Narrow Band Imaging Enhances the Detection Rate of Penetration and Aspiration in FEES.

PubMed

Nienstedt, Julie C; Müller, Frank; Nießen, Almut; Fleischer, Susanne; Koseki, Jana-Christiane; Flügel, Till; Pflug, Christina

2017-06-01

Narrow band imaging (NBI) is widely used in gastrointestinal, laryngeal, and urological endoscopy. Its original purpose was to visualize vessels and epithelial irregularities. Based on our observation that adding NBI to common white light (WL) improves the contrast of the test bolus in fiberoptic endoscopic evaluation of swallowing (FEES), we now investigated the potential value of NBI in swallowing disorders. 148 FEES images were analyzed from 74 consecutive patients with swallowing disorders, including 74 with and 74 without NBI. All images were evaluated by four dysphagia specialists. Findings were classified according to Rosenbek's penetration-aspiration scale modified for evaluating these FEES images. Intra- and inter-rater reliability was determined as well as observer confidence. A better visualization of the bolus is the main advantage of NBI in FEES. This generally leads to sharper optical contrasts and better detection of small bolus quantities. Accordingly, NBI enhances the detection rate of penetration and aspiration. On average, identification of laryngeal penetration increased from 40 to 73% and of aspiration from 13 to 24% (each p < 0.01) of patients. In contrast to WL alone, the use of NBI also markedly increased the inter- and intra-rater reliability (p < 0.01) and the rating confidence of all experts (p < 0.05). NBI is an easy and cost-effective tool simplifying dysphagia evaluation and shortening FEES evaluation time. It leads to a markedly higher detection rate of pathological findings. The significantly better intra- and inter-rater reliability argues further for a better overall reproducibly of FEES interpretation.

Analysis of the unbalanced NBI rotation experiments in the ISX-B, PLT and PDX tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stacey, W.M. Jr.; Ryu, C.M.; Malik, M.A.

1985-07-01

The recently developed Stacey-Sigmar theory for toroidal momentum confinement, which is based upon neoclassical gyroviscosity, has been applied to the analysis of the unbalanced NBI rotation experiments in ISX-B, PLT and PDX. Measured steady-state rotation velocities, momentum confinement times inferred therefrom and momentum confinement times inferred from rotation decay after termination of NBI were compared with theoretical predictions. Good agreement between theory and experiment was obtained over a wide range of the parameters which enter the theory (R,Z,T,B).

NBI-98854, a selective monoamine transport inhibitor for the treatment of tardive dyskinesia: A randomized, double-blind, placebo-controlled study.

PubMed

O'Brien, Christopher F; Jimenez, Roland; Hauser, Robert A; Factor, Stewart A; Burke, Joshua; Mandri, Daniel; Castro-Gayol, Julio C

2015-10-01

Tardive dyskinesia is a persistent movement disorder induced by chronic neuroleptic exposure. NBI-98854 is a novel, highly selective, vesicular monoamine transporter 2 inhibitor. We present results of a randomized, 6-week, double-blind, placebo-controlled, dose-titration study evaluating the safety, tolerability, and efficacy of NBI-98854 for the treatment of tardive dyskinesia. Male and female adult subjects with moderate or severe tardive dyskinesia were included. NBI-98854 or placebo was given once per day starting at 25 mg and then escalated by 25 mg to a maximum of 75 mg based on dyskinesia and tolerability assessment. The primary efficacy endpoint was the change in Abnormal Involuntary Movement Scale from baseline at week 6 scored by blinded, central video raters. The secondary endpoint was the Clinical Global Impression of Change-Tardive Dyskinesia score assessed by the blinded investigator. Two hundred five potential subjects were screened, and 102 were randomized; 76% of NBI-98854 subjects and 80% of placebo subjects reached the maximum allowed dose. Abnormal Involuntary Movement Scale scores for NBI-98854 compared with placebo were significantly reduced (p = 0.0005). Active drug was also superior on the Clinical Global Impression of Change-Tardive Dyskinesia (p < 0.0001). Treatment-emergent adverse event rates were 49% in the NBI-98854 and 33% in the placebo subjects. The most common adverse events (active vs. placebo) were fatigue and headache (9.8% vs. 4.1%) and constipation and urinary tract infection (3.9% vs. 6.1%). No clinically relevant changes in safety assessments were noted. NBI-98854 significantly improved tardive dyskinesia and was well tolerated in patients. These results support the phase 3 clinical trials of NBI-98854 now underway. © 2015 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Lack of evidence to favor specific preventive interventions in psychosis: a network meta-analysis.

PubMed

Davies, Cathy; Cipriani, Andrea; Ioannidis, John P A; Radua, Joaquim; Stahl, Daniel; Provenzani, Umberto; McGuire, Philip; Fusar-Poli, Paolo

2018-06-01

Preventing psychosis in patients at clinical high risk may be a promising avenue for pre-emptively ameliorating outcomes of the most severe psychiatric disorder. However, information on how each preventive intervention fares against other currently available treatment options remains unavailable. The aim of the current study was to quantify the consistency and magnitude of effects of specific preventive interventions for psychosis, comparing different treatments in a network meta-analysis. PsycINFO, Web of Science, Cochrane Central Register of Controlled Trials, and unpublished/grey literature were searched up to July 18, 2017, to identify randomized controlled trials conducted in individuals at clinical high risk for psychosis, comparing different types of intervention and reporting transition to psychosis. Two reviewers independently extracted data. Data were synthesized using network meta-analyses. The primary outcome was transition to psychosis at different time points and the secondary outcome was treatment acceptability (dropout due to any cause). Effect sizes were reported as odds ratios and 95% confidence intervals (CIs). Sixteen studies (2,035 patients, 57% male, mean age 20.1 years) reported on risk of transition. The treatments tested were needs-based interventions (NBI); omega-3 + NBI; ziprasidone + NBI; olanzapine + NBI; aripiprazole + NBI; integrated psychological interventions; family therapy + NBI; D-serine + NBI; cognitive behavioural therapy, French & Morrison protocol (CBT-F) + NBI; CBT-F + risperidone + NBI; and cognitive behavioural therapy, van der Gaag protocol (CBT-V) + CBT-F + NBI. The network meta-analysis showed no evidence of significantly superior efficacy of any one intervention over the others at 6 and 12 months (insufficient data were available after 12 months). Similarly, there was no evidence for intervention differences in acceptability at either time point. Tests for inconsistency were non-significant and sensitivity analyses controlling for different clustering of interventions and biases did not materially affect the interpretation of the results. In summary, this study indicates that, to date, there is no evidence that any specific intervention is particularly effective over the others in preventing transition to psychosis. Further experimental research is needed. © 2018 World Psychiatric Association.

Lack of evidence to favor specific preventive interventions in psychosis: a network meta‐analysis

PubMed Central

Davies, Cathy; Cipriani, Andrea; Ioannidis, John P.A.; Radua, Joaquim; Stahl, Daniel; Provenzani, Umberto; McGuire, Philip; Fusar‐Poli, Paolo

2018-01-01

Preventing psychosis in patients at clinical high risk may be a promising avenue for pre‐emptively ameliorating outcomes of the most severe psychiatric disorder. However, information on how each preventive intervention fares against other currently available treatment options remains unavailable. The aim of the current study was to quantify the consistency and magnitude of effects of specific preventive interventions for psychosis, comparing different treatments in a network meta‐analysis. PsycINFO, Web of Science, Cochrane Central Register of Controlled Trials, and unpublished/grey literature were searched up to July 18, 2017, to identify randomized controlled trials conducted in individuals at clinical high risk for psychosis, comparing different types of intervention and reporting transition to psychosis. Two reviewers independently extracted data. Data were synthesized using network meta‐analyses. The primary outcome was transition to psychosis at different time points and the secondary outcome was treatment acceptability (dropout due to any cause). Effect sizes were reported as odds ratios and 95% confidence intervals (CIs). Sixteen studies (2,035 patients, 57% male, mean age 20.1 years) reported on risk of transition. The treatments tested were needs‐based interventions (NBI); omega‐3 + NBI; ziprasidone + NBI; olanzapine + NBI; aripiprazole + NBI; integrated psychological interventions; family therapy + NBI; D‐serine + NBI; cognitive behavioural therapy, French & Morrison protocol (CBT‐F) + NBI; CBT‐F + risperidone + NBI; and cognitive behavioural therapy, van der Gaag protocol (CBT‐V) + CBT‐F + NBI. The network meta‐analysis showed no evidence of significantly superior efficacy of any one intervention over the others at 6 and 12 months (insufficient data were available after 12 months). Similarly, there was no evidence for intervention differences in acceptability at either time point. Tests for inconsistency were non‐significant and sensitivity analyses controlling for different clustering of interventions and biases did not materially affect the interpretation of the results. In summary, this study indicates that, to date, there is no evidence that any specific intervention is particularly effective over the others in preventing transition to psychosis. Further experimental research is needed. PMID:29856551

A pharmacokinetic evaluation of five H1 antagonists after an oral and intravenous microdose to human subjects

PubMed Central

Madan, Ajay; O'Brien, Zhihong; Wen, Jianyun; O'Brien, Chris; Farber, Robert H; Beaton, Graham; Crowe, Paul; Oosterhuis, Berend; Garner, R Colin; Lappin, Graham; Bozigian, Haig P

2009-01-01

AIMS To evaluate the pharmacokinetics (PK) of five H1 receptor antagonists in human volunteers after a single oral and intravenous (i.v.) microdose (0.1 mg). METHODS Five H1 receptor antagonists, namely NBI-1, NBI-2, NBI-3, NBI-4 and diphenhydramine, were administered to human volunteers as a single 0.1-mg oral and i.v. dose. Blood samples were collected up to 48 h, and the parent compound in the plasma extract was quantified by high-performance liquid chromatography and accelerator mass spectroscopy. RESULTS The median clearance (CL), apparent volume of distribution (Vd) and apparent terminal elimination half-life (t1/2) of diphenhydramine after an i.v. microdose were 24.7 l h−1, 302 l and 9.3 h, and the oral Cmax and AUC0–∞ were 0.195 ng ml−1 and 1.52 ng h ml−1, respectively. These data were consistent with previously published diphenhydramine data at 500 times the microdose. The rank order of oral bioavailability of the five compounds was as follows: NBI-2 > NBI-1 > NBI-3 > diphenhydramine > NBI-4, whereas the rank order for CL was NBI-4 > diphenhydramine > NBI-1 > NBI-3 > NBI-2. CONCLUSIONS Human microdosing provided estimates of clinical PK of four structurally related compounds, which were deemed useful for compound selection. PMID:19523012

A pharmacokinetic evaluation of five H(1) antagonists after an oral and intravenous microdose to human subjects.

PubMed

Madan, Ajay; O'Brien, Zhihong; Wen, Jianyun; O'Brien, Chris; Farber, Robert H; Beaton, Graham; Crowe, Paul; Oosterhuis, Berend; Garner, R Colin; Lappin, Graham; Bozigian, Haig P

2009-03-01

To evaluate the pharmacokinetics (PK) of five H(1) receptor antagonists in human volunteers after a single oral and intravenous (i.v.) microdose (0.1 mg). Five H(1) receptor antagonists, namely NBI-1, NBI-2, NBI-3, NBI-4 and diphenhydramine, were administered to human volunteers as a single 0.1-mg oral and i.v. dose. Blood samples were collected up to 48 h, and the parent compound in the plasma extract was quantified by high-performance liquid chromatography and accelerator mass spectroscopy. The median clearance (CL), apparent volume of distribution (V(d)) and apparent terminal elimination half-life (t(1/2)) of diphenhydramine after an i.v. microdose were 24.7 l h(-1), 302 l and 9.3 h, and the oral C(max) and AUC(0-infinity) were 0.195 ng ml(-1) and 1.52 ng h ml(-1), respectively. These data were consistent with previously published diphenhydramine data at 500 times the microdose. The rank order of oral bioavailability of the five compounds was as follows: NBI-2 > NBI-1 > NBI-3 > diphenhydramine > NBI-4, whereas the rank order for CL was NBI-4 > diphenhydramine > NBI-1 > NBI-3 > NBI-2. Human microdosing provided estimates of clinical PK of four structurally related compounds, which were deemed useful for compound selection.

Alfvén cascades in JET discharges with NBI-heating

NASA Astrophysics Data System (ADS)

Sharapov, S. E.; Alper, B.; Baranov, Yu. F.; Berk, H. L.; Borba, D.; Boswell, C.; Breizman, B. N.; Challis, C. D.; de Baar, M.; DeLa Luna, E.; Evangelidis, E. A.; Hacquin, S.; Hawkes, N. C.; Kiptily, V. G.; Pinches, S. D.; Sandquist, P.; Voitsekhovich, I.; Young, N. P.; Contributors, JET-EFDA

2006-10-01

Alfvén cascade (AC) eigenmodes excited by energetic ions accelerated with ion-cyclotron resonance heating in JET reversed-shear discharges are studied experimentally in high-density plasmas fuelled by neutral beam injection (NBI) and by deuterium pellets. The recently developed O-mode interferometry technique and Mirnov coils are employed for detecting ACs. The spontaneous improvements in plasma confinement (internal transport barrier (ITB) triggering events) and grand ACs are found to correlate within 0.2 s in JET plasmas with densities up to ~5 × 1019 m-3. Measurements with high time resolution show that ITB triggering events happen before 'grand' ACs in the majority of JET discharges, indicating that this improvement in confinement is likely to be associated with the decrease in the density of rational magnetic surfaces just before qmin(t) passes an integer value. Experimentally observed ACs excited by sub-Alfvénic NBI-produced ions with parallel velocities as low as V||NBI ap 0.2 · VA are found to be most likely associated with the geodesic acoustic effect that significantly modifies the shear-Alfvén dispersion relation at low frequency. Experiments were performed with a tritium NBI-blip (short time pulse) into JET plasmas with NBI-driven ACs. Although considerable NBI-driven AC activity was present, good agreement was found both in the radial profile and in the time evolution of DT neutrons between the neutron measurements and the TRANSP code modelling based on the Coulomb collision model, indicating the ACs have at most a small effect on fast particle confinement in this case.

Optical Design with Narrow-Band Imaging for a Capsule Endoscope.

PubMed

Yen, Chih-Ta; Lai, Zong-Wei; Lin, Yu-Ting; Cheng, Hsu-Chih

2018-01-01

The study proposes narrow-band imaging (NBI) lens design of 415 nm and 540 nm of a capsule endoscope (CE). The researches show that in terms of the rate of accuracy in detecting and screening neoplastic and nonneoplastic intestinal lesions, the NBI system outperformed that of traditional endoscopes and rivaled that of chromoendoscopes. In the proposed NBI CE optical system, the simulation result shows the field of view (FOV) was 109.8°; the modulation transfer function (MTF) could achieve 12.5% at 285 lp/mm and 34.1% at 144 lp/mm. The relative illumination reaches more than 60%, and the system total length was less than 4 mm. Finally, this design provides high-quality images for a 300-megapixel 1/4 ″ CMOS image sensor with a pixel size of 1.75  μ m.

High magnification bronchovideoscopy combined with narrow band imaging could detect capillary loops of angiogenic squamous dysplasia in heavy smokers at high risk for lung cancer.

PubMed

Shibuya, K; Hoshino, H; Chiyo, M; Iyoda, A; Yoshida, S; Sekine, Y; Iizasa, T; Saitoh, Y; Baba, M; Hiroshima, K; Ohwada, H; Fujisawa, T

2003-11-01

We investigated the use of high magnification bronchovideoscopy combined with narrow band imaging (NBI) for the detailed examination of angiogenic squamous dysplasia (ASD). This was carried out in relation to bronchial vascular patterns with abnormal mucosal fluorescence in heavy smokers at high risk for lung cancer. Forty eight patients with sputum cytology specimens suspicious or positive for malignancy were entered into the study. Conventional white light and fluorescence bronchoscopic examination was first performed. Observations by high magnification bronchovideoscopy with conventional white light were made primarily at sites of abnormal fluorescence, and then repeated with NBI light to examine microvascular networks in the bronchial mucosa. Spectral features on the RGB (Red/Green/Blue) sequential videoscope system were changed from the conventional RGB broadband filter to the new NBI filter. The wavelength ranges of the new NBI filter were B1: 400-430 nm, B2: 420-470 nm, and G: 560-590 nm. ASD tissues were also examined using a confocal laser scanning microscope equipped with argon-krypton (488 nm) and argon (514 nm) laser sources. The microvessels, vascular networks of various grades, and dotted vessels in ASD tissues were clearly observed in NBI-B1 images. Diameters of the dotted vessels visible on NBI-B1 images agreed with the diameters of ASD capillary blood vessels diagnosed by pathological examination. Capillary blood vessels were also clearly visualised by green fluorescence by confocal laser scanning microscopy. There was a significant association between the frequency of dotted vessels by NBI-B1 imaging and tissues confirmed as ASD pathologically (p=0.002). High magnification bronchovideoscopy combined with NBI was useful in the detection of capillary blood vessels in ASD lesions at sites of abnormal fluorescence. This may enable the discrimination between ASD and another pre-invasive bronchial lesion.

Dual-focus versus conventional magnification endoscopy for the diagnosis of superficial squamous neoplasms in the pharynx and esophagus: a randomized trial.

PubMed

Goda, Kenichi; Dobashi, Akira; Yoshimura, Noboru; Aihara, Hiroyuki; Kato, Masayuki; Sumiyama, Kazuki; Toyoizumi, Hirobumi; Kato, Tomohiro; Saijo, Hiroki; Ikegami, Masahiro; Tajiri, Hisao

2016-04-01

Conventional magnification narrow-band imaging (CM-NBI) endoscopy has demonstrated high diagnostic accuracy for superficial squamous neoplasms in the pharynx and esophagus. This study aimed to evaluate the diagnostic utility of the newly developed dual-focus NBI (DF-NBI) compared with that of CM-NBI. We recruited patients with squamous cell carcinoma (SCC) in the head and neck, or esophagus, or with a history of SCC. The primary endpoint of this prospective controlled non-inferiority trial was the sensitivity of DF-NBI and CM-NBI for detecting superficial carcinoma in the pharynx and esophagus. Secondary endpoints included other diagnostic values and the resolving power of each endoscope. Superficial carcinoma was defined as high grade dysplasia and SCC invading up to the submucosal layer. The study included 93 patients. A total of 28 superficial carcinomas were detected in the pharynx and esophagus. The sensitivities of DF-NBI and CM-NBI for superficial carcinoma were 82 % and 71 %, respectively. The lower limit of the 90 % confidence interval for the difference between the sensitivities exceeded the non-inferiority threshold. The specificity and overall accuracy of DF-NBI vs. CM-NBI were 93 % vs. 90 % and 91 % vs. 86 %, respectively (both non-significant differences). The maximum resolving power of a conventional magnification endoscope was significantly higher than a dual-focus endoscope (7.2 µm vs. 11.6 µm: P < 0.001). The findings indicate the non-inferiority of DF-NBI versus CM-NBI in detecting superficial carcinoma in the pharynx and esophagus. DF-NBI appears to have a resolving power that, although significantly lower, is sufficient to achieve high diagnostic accuracy, comparable to that of CM-NBI.University Hospital Medical Information Network (UMIN, No. 000007585). © Georg Thieme Verlag KG Stuttgart · New York.

Data management and data enrichment for systems biology projects.

PubMed

Wittig, Ulrike; Rey, Maja; Weidemann, Andreas; Müller, Wolfgang

2017-11-10

Collecting, curating, interlinking, and sharing high quality data are central to de.NBI-SysBio, the systems biology data management service center within the de.NBI network (German Network for Bioinformatics Infrastructure). The work of the center is guided by the FAIR principles for scientific data management and stewardship. FAIR stands for the four foundational principles Findability, Accessibility, Interoperability, and Reusability which were established to enhance the ability of machines to automatically find, access, exchange and use data. Within this overview paper we describe three tools (SABIO-RK, Excemplify, SEEK) that exemplify the contribution of de.NBI-SysBio services to FAIR data, models, and experimental methods storage and exchange. The interconnectivity of the tools and the data workflow within systems biology projects will be explained. For many years we are the German partner in the FAIRDOM initiative (http://fair-dom.org) to establish a European data and model management service facility for systems biology. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Sensitivity and specificity of narrow-band imaging nasoendoscopy compared to histopathology results in patients with suspected nasopharyngeal carcinoma

NASA Astrophysics Data System (ADS)

Adham, M.; Musa, Z.; Lisnawati; Suryati, I.

2017-08-01

Nasopharyngeal carcinoma (NPC) is a disease which is prevalent in developing countries like Indonesia. There were 164 new cases of nasopharyngeal carcinoma in the ear, nose, and throat (ENT) oncology outpatient clinic of the Cipto Mangunkusumo hospital in 2014, and 142 cases in 2015. Unfortunately, almost all of these cases presented at an advanced stage. The success of nasopharyngeal carcinoma treatment is largely determined by the stage when patients are diagnosed; it is critical to diagnose NPC as early as possible. Narrow-band imaging (NBI) is an endoscopic instrument with a light system that can improve the visualization of blood vessels of mucosal epithelial malignant tumors. NBI is expected to help clinicians to assess whether a lesion is malignant or not; to do so, it is important to know the value of sensitivity and specificity. This study is a cross-sectional form of a diagnostic test which was performed in the outpatient clinic of the ENT Head and Neck Surgery Department for the Cipto Mangunkusumo Hospital, from January to June 2016, and involved 56 subjects. Patients with a nasopharyngeal mass discovered by physical examination or imaging, and a suspected nasopharyngeal carcinoma were included as a subject. An NBI examination and biopsy was performed locally. Based on this research, NBI could be used as a screening tool for nasopharyngeal carcinoma with high sensitivity (100%), but with a low specificity result (6.7%).

Narrow band imaging in the diagnosis of intra-epithelial and invasive laryngeal squamous cell carcinoma: a preliminary report of two cases.

PubMed

Masaki, Takashi; Katada, Chikatoshi; Nakayama, Meijin; Takeda, Masahiko; Miyamoto, Shunsuke; Seino, Yutomo; Koizumi, Wasaburo; Tanabe, Satoshi; Horiguchi, Satoshi; Okamoto, Makito

2009-12-01

Narrow band imaging (NBI) is a novel optical technique that enhances the diagnostic capability of the gastrointestinal endoscope (GIE) by illuminating the intraepithelial papillary capillary loop (IPCL) using narrow bandwidth filters in a red-green-blue sequential illumination system (CV-260SL processor and CLV-260SL light source, Olympus Optical Co. Ltd, Tokyo, Japan). The NBI filter sets (415 nm and 540 nm) are selected to obtain fine images of the microvascular structure. Because 415 nm is the hemoglobin absorption band, capillaries on the mucosal surface can be seen most clearly at this wavelength. NBI is able to represent more clearly both capillary patterns and the boundary between different types of tissue, which are necessary for diagnosing a tumor in its early stage (Gono K, Yamazaki K, Doguchi N, Nonami T, Obi T, Yamaguchi M, et al. Endoscopic observation of tissue by narrow band illumination. Opt Rev 2003;10:211-215, Gono K, Obi T, Yamaguchi M, Ohyama N, Machida H, Sano Y, et al. Appearance of enhanced tissue feature in narrow-band endoscopic imaging. J Biomed Opt 2004;9:568-577). We present two patients with laryngeal squamous cell carcinoma in whom the spread and the depth of invasion was evaluated with transnasal GIE equipped with NBI. Based on our results, the vascular neoplastic changes of carcinoma in situ of the larynx could be similar to carcinoma in situ of the esophagus.

A Web-Based Education Program for Colorectal Lesion Diagnosis with Narrow Band Imaging Classification.

PubMed

Aihara, Hiroyuki; Kumar, Nitin; Thompson, Christopher C

2018-04-19

An education system for narrow band imaging (NBI) interpretation requires sufficient exposure to key features. However, access to didactic lectures by experienced teachers is limited in the United States. To develop and assess the effectiveness of a colorectal lesion identification tutorial. In the image analysis pretest, subjects including 9 experts and 8 trainees interpreted 50 white light (WL) and 50 NBI images of colorectal lesions. Results were not reviewed with subjects. Trainees then participated in an online tutorial emphasizing NBI interpretation in colorectal lesion analysis. A post-test was administered and diagnostic yields were compared to pre-education diagnostic yields. Under the NBI mode, experts showed higher diagnostic yields (sensitivity 91.5% [87.3-94.4], specificity 90.6% [85.1-94.2], and accuracy 91.1% [88.5-93.7] with substantial interobserver agreement [κ value 0.71]) compared to trainees (sensitivity 89.6% [84.8-93.0], specificity 80.6% [73.5-86.3], and accuracy 86.0% [82.6-89.2], with substantial interobserver agreement [κ value 0.69]). The online tutorial improved the diagnostic yields of trainees to the equivalent level of experts (sensitivity 94.1% [90.0-96.6], specificity 89.0% [83.0-93.2], and accuracy 92.0% [89.3-94.7], p < 0.001 with substantial interobserver agreement [κ value 0.78]). This short, online tutorial improved diagnostic performance and interobserver agreement. © 2018 S. Karger AG, Basel.

Effectiveness of computer-aided diagnosis of colorectal lesions using novel software for magnifying narrow-band imaging: a pilot study.

PubMed

Tamai, Naoto; Saito, Yutaka; Sakamoto, Taku; Nakajima, Takeshi; Matsuda, Takahisa; Sumiyama, Kazuki; Tajiri, Hisao; Koyama, Ryosuke; Kido, Shoji

2017-08-01

 Magnifying narrow-band imaging (M-NBI) enables detailed observation of microvascular architecture and can be used in endoscopic diagnosis of colorectal lesion. However, in clinical practice, differential diagnosis and estimation of invasion depth of colorectal lesions based on M-NBI findings require experience. Therefore, developing computer-aided diagnosis (CAD) for M-NBI would be beneficial for clinical practice. The aim of this study was to evaluate the effectiveness of software for CAD of colorectal lesions. In collaboration with Yamaguchi University, we developed novel software that enables CAD of colorectal lesions using M-NBI images. This software for CAD further specifically divides original Sano's colorectal M-NBI classification into 3 groups (group A, capillary pattern [CP] type I; group B, CP type II + CP type IIIA; group C, CP type IIIB), which describe hyperplastic polyps (HPs), adenoma/adenocarcinoma (intramucosal [IM] to submucosal [SM]-superficial) lesions, and SM-deep lesions, respectively. We retrospectively reviewed 121 lesions evaluated using M-NBI. The 121 reviewed lesions included 21 HP, 80 adenoma/adenocarcinoma (IM to SM-superficial), and 20 SM-deep lesions. The concordance rate between the CAD and the diagnosis of the experienced endoscopists was 90.9 %. The sensitivity, specificity, positive and negative predictive values, and accuracy of the CAD for neoplastic lesions were 83.9 %, 82.6 %, 53.1 %, 95.6 %, and 82.8 %, respectively. The values for SM-deep lesions were 83.9 %, 82.6 %, 53.1 %, 95.6 %, and 82.8 %, respectively.  Relatively high diagnostic values were obtained using CAD. This software for CAD could possibly lead to a wider use of M-NBI in the endoscopic diagnosis of colorectal lesions.

[Value of narrow band imaging endoscopy in detection of early laryngeal squamous cell carcinoma].

PubMed

Staníková, L; Kučová, H; Walderová, R; Zeleník, K; Šatanková, J; Komínek, P

2015-01-01

Narrow band imaging (NBI) is an endoscopic method using filtered wavelengths in detection of microvascular abnormalities associated with preneoplastic and neoplastic changes of the mucosa. The aim of the study is to evaluate the value of NBI endoscopy in the dia-gnosis of laryngeal precancerous and early stages of cancerous lesions and to investigate impact of NBI method in prehistological diagnostics in vivo. One hundred patients were enrolled in the study and their larynx was investigated using white light HD endoscopy and narrow band imaging between 6/ 2013- 10/ 2014. Indication criteria included chronic laryngitis, hoarseness for more than three weeks or macroscopic laryngeal lesion. Features of mucosal lesions were evaluated by white light endoscopy and afterwards were compared with intra-epithelial papillary capillary loop changes, viewed using NBI endoscopy. Suspicious lesions (leukoplakia, exophytic tumors, recurrent respiratory papillomatosis and/ or malignant type of vascular network by NBI endoscopy) were evaluated by histological analysis, results were compared with prehistological NBI dia-gnosis. Using NBI endoscopy, larger demarcation of pathological mucosal features than in white light visualization were recorded in 32/ 100 (32.0%) lesions, in 4/ 100 (4.0%) cases even new lesions were detected only by NBI endoscopy. 63/ 100 (63.0%) suspected lesions were evaluated histologically -  malign changes (carcinoma in situ or invasive carcinoma) were observed in 25/ 63 (39.7%). Prehistological diagnostics of malignant lesions using NBI endoscopy were in agreement with results of histological examination in 23/ 25 (92.0%) cases. The sensitivity of NBI in detecting malignant lesions was 89.3%, specificity of this method was 94.9%. NBI endoscopy is a promising optical technique enabling in vivo differentiation of superficial neoplastic lesions. These results suggest endoscopic NBI may be useful in the early detection of laryngeal cancer and precancerous lesions.

Use of narrow-band imaging bronchoscopy in detection of lung cancer.

PubMed

Zaric, Bojan; Perin, Branislav

2010-05-01

Narrow-band imaging (NBI) is a new endoscopic technique designed for detection of pathologically altered submucosal and mucosal microvascular patterns. The combination of magnification videobronchoscopy and NBI showed great potential in the detection of precancerous and cancerous lesions of the bronchial mucosa. The preliminary studies confirmed supremacy of NBI over white-light videobronchoscopy in the detection of premalignant and malignant lesions. Pathological patterns of capillaries in bronchial mucosa are known as Shibuya's descriptors (dotted, tortuous and abrupt-ending blood vessels). Where respiratory endoscopy is concerned, the NBI is still a 'technology in search of proper indication'. More randomized trials are necessary to confirm the place of NBI in the diagnostic algorithm, and more trials are needed to evaluate the relation of NBI to autofluorescence videobronchoscopy and to white-light magnification videobronchoscopy. Considering the fact that NBI examination of the tracheo-bronchial tree is easy, reproducible and clear to interpret, it is certain that NBI videobronchoscopy will play a significant role in the future of lung cancer detection and staging.

Feasibility of a motional Stark effect system on the TCV tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegrist, M.R.; Hawkes, N.; Weisen, H.

This paper presents a feasibility study for a motional Stark effect (MSE) [F. M. Levinton et al., Phys. Rev. Lett. 63, 2060 (1989)] diagnostic on the TCV tokamak. A numerical simulation code has been used to identify the optimal port arrangement and geometrical layout. It predicts the expected measurement accuracy for a range of typical plasma scenarios. With the existing neutral beam injector (NBI) and a detection system based on current day technology, it should be possible to determine the safety factor with an accuracy of the order of 5%. A vertically injected beam through the plasma center would allowmore » one to measure plasmas which are centered above the midplane, a common occurrence in connection with electron cyclotron resonance heating and electron cyclotron current drive experiments. In this case a new and ideally more powerful NBI would be required.« less

An enhanced narrow-band imaging method for the microvessel detection

NASA Astrophysics Data System (ADS)

Yu, Feng; Song, Enmin; Liu, Hong; Wan, Youming; Zhu, Jun; Hung, Chih-Cheng

2018-02-01

A medical endoscope system combined with the narrow-band imaging (NBI), has been shown to be a superior diagnostic tool for early cancer detection. The NBI can reveal the morphologic changes of microvessels in the superficial cancer. In order to improve the conspicuousness of microvessel texture, we propose an enhanced NBI method to improve the conspicuousness of endoscopic images. To obtain the more conspicuous narrow-band images, we use the edge operator to extract the edge information of the narrow-band blue and green images, and give a weight to the extracted edges. Then, the weighted edges are fused with the narrow-band blue and green images. Finally, the displayed endoscopic images are reconstructed with the enhanced narrow-band images. In addition, we evaluate the performance of enhanced narrow-band images with different edge operators. Experimental results indicate that the Sobel and Canny operators achieve the best performance of all. Compared with traditional NBI method of Olympus company, our proposed method has more conspicuous texture of microvessel.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

PubMed Central

Yoshida, Naohisa; Yagi, Nobuaki; Yanagisawa, Akio; Naito, Yuji

2012-01-01

Recently, image-enhanced endoscopy (IEE) has been used to diagnose gastrointestinal tumors. This method is a change from conventional white-light (WL) endoscopy without dyeing solution, requiring only the push of a button. In IEE, there are many advantages in diagnosis of neoplastic tumors, evaluation of invasion depth for cancerous lesions, and detection of neoplastic lesions. In narrow band imaging (NBI) systems (Olympus Medical Co., Tokyo, Japan), optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used. Mucosal surface blood vessels are seen most clearly at 415 nm, which is the wavelength that corresponds to the hemoglobin absorption band, while vessels in the deep layer of the mucosa can be detected at 540 nm. Thus, NBI also can detect pit-like structures named surface pattern. The flexible spectral imaging color enhancement (FICE) system (Fujifilm Medical Co., Tokyo, Japan) is also an IEE but different to NBI. FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images. FICE can enhance vascular and surface patterns. The autofluorescence imaging (AFI) video endoscope system (Olympus Medical Co., Tokyo, Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions. AFI light comprises a blue light for emitting and a green light for hemoglobin absorption. The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment. PMID:23293724

Analysis of Radiation Transport Due to Activated Coolant in the ITER Neutral Beam Injection Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Royston, Katherine; Wilson, Stephen C.; Risner, Joel M.

Detailed spatial distributions of the biological dose rate due to a variety of sources are required for the design of the ITER tokamak facility to ensure that all radiological zoning limits are met. During operation, water in the Integrated loop of Blanket, Edge-localized mode and vertical stabilization coils, and Divertor (IBED) cooling system will be activated by plasma neutrons and will flow out of the bioshield through a complex system of pipes and heat exchangers. This paper discusses the methods used to characterize the biological dose rate outside the tokamak complex due to 16N gamma radiation emitted by the activatedmore » coolant in the Neutral Beam Injection (NBI) cell of the tokamak building. Activated coolant will enter the NBI cell through the IBED Primary Heat Transfer System (PHTS), and the NBI PHTS will also become activated due to radiation streaming through the NBI system. To properly characterize these gamma sources, the production of 16N, the decay of 16N, and the flow of activated water through the coolant loops were modeled. The impact of conservative approximations on the solution was also examined. Once the source due to activated coolant was calculated, the resulting biological dose rate outside the north wall of the NBI cell was determined through the use of sophisticated variance reduction techniques. The AutomateD VAriaNce reducTion Generator (ADVANTG) software implements methods developed specifically to provide highly effective variance reduction for complex radiation transport simulations such as those encountered with ITER. Using ADVANTG with the Monte Carlo N-particle (MCNP) radiation transport code, radiation responses were calculated on a fine spatial mesh with a high degree of statistical accuracy. In conclusion, advanced visualization tools were also developed and used to determine pipe cell connectivity, to facilitate model checking, and to post-process the transport simulation results.« less

Analysis of Radiation Transport Due to Activated Coolant in the ITER Neutral Beam Injection Cell

DOE PAGES

Royston, Katherine; Wilson, Stephen C.; Risner, Joel M.; ...

2017-07-26

Detailed spatial distributions of the biological dose rate due to a variety of sources are required for the design of the ITER tokamak facility to ensure that all radiological zoning limits are met. During operation, water in the Integrated loop of Blanket, Edge-localized mode and vertical stabilization coils, and Divertor (IBED) cooling system will be activated by plasma neutrons and will flow out of the bioshield through a complex system of pipes and heat exchangers. This paper discusses the methods used to characterize the biological dose rate outside the tokamak complex due to 16N gamma radiation emitted by the activatedmore » coolant in the Neutral Beam Injection (NBI) cell of the tokamak building. Activated coolant will enter the NBI cell through the IBED Primary Heat Transfer System (PHTS), and the NBI PHTS will also become activated due to radiation streaming through the NBI system. To properly characterize these gamma sources, the production of 16N, the decay of 16N, and the flow of activated water through the coolant loops were modeled. The impact of conservative approximations on the solution was also examined. Once the source due to activated coolant was calculated, the resulting biological dose rate outside the north wall of the NBI cell was determined through the use of sophisticated variance reduction techniques. The AutomateD VAriaNce reducTion Generator (ADVANTG) software implements methods developed specifically to provide highly effective variance reduction for complex radiation transport simulations such as those encountered with ITER. Using ADVANTG with the Monte Carlo N-particle (MCNP) radiation transport code, radiation responses were calculated on a fine spatial mesh with a high degree of statistical accuracy. In conclusion, advanced visualization tools were also developed and used to determine pipe cell connectivity, to facilitate model checking, and to post-process the transport simulation results.« less

Development of a novel image-based program to teach narrow-band imaging.

PubMed

Dumas, Cedric; Fielding, David; Coles, Timothy; Good, Norm

2016-08-01

Narrow-band imaging (NBI) is a widely available endoscopic imaging technology; however, uptake of the technique could be improved. Teaching new imaging techniques and assessing trainees' performance can be a challenging exercise during a 1-day workshop. To support NBI training, we developed an online training tool (Medimq) to help experts train novices in NBI bronchoscopy that could assess trainees' performance and provide feedback before the close of the 1-day course. The present study determines whether trainees' capacity to identify relevant pathology increases with the proposed interactive testing method. Two groups of 20 and 18 bronchoscopists have attended an NBI course where they did a pretest and post-test before and after the main lecture, and a follow-up test 4 weeks later to measure retention of knowledge. We measured their ability to mark normal and abnormal 'biopsy size' areas on bronchoscopic NBI images for biopsy. These markings were compared with areas marked by experts on the same images. The first group results were used to pilot the test. After modifications, the results of the improved test for group 2 showed trainees improved by 32% (total class average normalized gain) in detecting normal or abnormal areas. On follow-up testing, Group 2 improved by 23%. The overall class average normalized gain of 32% shows our test can be used to improve trainees' competency in analyzing NBI Images. The testing method (and tool) can be used to measure the follow up 4 weeks later. Better follow-up test results would be expected with more frequent practice by trainees after the course. © The Author(s), 2016.

Usefulness of magnifying endoscopy with narrow-band imaging for diagnosis of depressed gastric lesions

PubMed Central

SUMIE, HIROAKI; SUMIE, SHUJI; NAKAHARA, KEITA; WATANABE, YASUTOMO; MATSUO, KEN; MUKASA, MICHITA; SAKAI, TAKESHI; YOSHIDA, HIKARU; TSURUTA, OSAMU; SATA, MICHIO

2014-01-01

The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) for the diagnosis of early gastric cancer is well known, however, there are no evaluation criteria. The aim of this study was to devise and evaluate a novel diagnostic algorithm for ME-NBI in depressed early gastric cancer. Between August, 2007 and May, 2011, 90 patients with a total of 110 depressed gastric lesions were enrolled in the study. A diagnostic algorithm was devised based on ME-NBI microvascular findings: microvascular irregularity and abnormal microvascular patterns (fine network, corkscrew and unclassified patterns). The diagnostic efficiency of the algorithm for gastric cancer and histological grade was assessed by measuring its mean sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy. Furthermore, inter- and intra-observer variation were measured. In the differential diagnosis of gastric cancer from non-cancerous lesions, the mean sensitivity, specificity, PPV, NPV, and accuracy of the diagnostic algorithm were 86.7, 48.0, 94.4, 26.7, and 83.2%, respectively. Furthermore, in the differential diagnosis of undifferentiated adenocarcinoma from differentiated adenocarcinoma, the mean sensitivity, specificity, PPV, NPV, and accuracy of the diagnostic algorithm were 61.6, 86.3, 69.0, 84.8, and 79.1%, respectively. For the ME-NBI final diagnosis using this algorithm, the mean κ values for inter- and intra-observer agreement were 0.50 and 0.77, respectively. In conclusion, the diagnostic algorithm based on ME-NBI microvascular findings was convenient and had high diagnostic accuracy, reliability and reproducibility in the differential diagnosis of depressed gastric lesions. PMID:24649321

Diagnostic values of dual focus narrow band imaging and probe-based confocal laser endomicroscopy in FAP-related duodenal adenoma.

PubMed

Pittayanon, Rapat; Rerknimitr, Rungsun; Imraporn, Boonlert; Wisedopas, Naruemon; Kullavanijaya, Pinit

2015-10-01

Familial adenomatous polyposis (FAP) is associated with an increased risk of development of periampullary and nonampullary adenoma. Either routine biopsy or endoscopic removal of the lesion is generally required to identify the presence of adenoma. Because the risk of tissue sampling from the ampulla is high and nonampullary polyps are sometimes numerous, resection of all the lesions is time-consuming. This study aimed to evaluate the diagnostic values of duodenal adenoma by dual focus NBI (dNBI) and probe-based confocal endomicroscopy (pCLE) in FAP patients. The authors conducted a diagnostic study in a single tertiary-care referral center. Surveillance esophagogastroduodenoscopy with dNBI and pCLE was performed on 26 patients with FAP for real-time adenoma diagnosis by two different endoscopists; one used dNBI and the other pCLE. Histology from the matched lesion was used as the gold standard. A total of 55 matched biopsies (25 ampullas, 30 nonampullas) were performed. The sensitivity, specificity, post predictive value (PPV), negative predictive value (NPV), and accuracy of dNBI vs. pCLE from all duodenal lesions were 96.9 % vs. 93.8 %, 78.3 % vs. 81 %, 86.1 % vs. 88.2 %, 94.7 vs. 89.5 %, and 92.4 % vs. 88.6 %, respectively. For surveillance of periampullary and nonampullary adenoma in patients with FAP, the real-time readings provided a high degree of diagnostic value when histology was used as the gold standard. ( NCT02162173).

Ion source development for a photoneutralization based NBI system for fusion reactors

NASA Astrophysics Data System (ADS)

Simonin, A.; de Esch, H. P. L.; Garibaldi, P.; Grand, C.; Bechu, S.; Bès, A.; Lacoste, A.

2015-04-01

The next step after ITER is to demonstrate the viability and generation of electricity by a future fusion reactor (DEMO). The specifications required to operate an NBI system on DEMO are very demanding. The system has to provide a very high level of power and energy, ~100MW of D° beam at 1MeV, including high wall-plug efficiency (η > 60%). For this purpose, a new injector concept, called Siphore, is under investigation between CEA and French universities. Siphore is based on the stripping of the accelerated negative ions by photo-detachment provided by several Fabry-Perot cavities (3.5MW of light power per cavity) implemented along the D- beam. The beamline is designed to be tall and narrow in order that the photon flux overlaps the entire negative ion beam. The paper will describe the present R&D at CEA which addresses the development of an ion source and pre-accelerator prototypes for Siphore, the main goal being to produce an intense negative ion beam sheet. The negative ion source Cybele is based on a magnetized plasma column where hot electrons are emitted from the source center. Parametric studies of the source are performed using Langmuir probes in order to characterize the plasma and to compare with numerical models being developed in French universities.

Narrow-band imaging for the computer assisted diagnosis in patients with Barrett's esophagus

NASA Astrophysics Data System (ADS)

Kage, Andreas; Raithel, Martin; Zopf, Steffen; Wittenberg, Thomas; Münzenmayer, Christian

2009-02-01

Cancer of the esophagus has the worst prediction of all known cancers in Germany. The early detection of suspicious changes in the esophagus allows therapies that can prevent the cancer. Barrett's esophagus is a premalignant change of the esophagus that is a strong indication for cancer. Therefore there is a big interest to detect Barrett's esophagus as early as possible. The standard examination is done with a videoscope where the physician checks the esophagus for suspicious regions. Once a suspicious region is found, the physician takes a biopsy of that region to get a histological result of it. Besides the traditional white light for the illumination there is a new technology: the so called narrow-band Imaging (NBI). This technology uses a smaller spectrum of the visible light to highlight the scene captured by the videoscope. Medical studies indicate that the use of NBI instead of white light can increase the rate of correct diagnoses of a physician. In the future, Computer-Assisted Diagnosis (CAD) which is well known in the area of mammography might be used to support the physician in the diagnosis of different lesions in the esophagus. A knowledge-based system which uses a database is a possible solution for this task. For our work we have collected NBI images containing 326 Regions of Interest (ROI) of three typical classes: epithelium, cardia mucosa and Barrett's esophagus. We then used standard texture analysis features like those proposed by Haralick, Chen, Gabor and Unser to extract features from every ROI. The performance of the classification was evaluated with a classifier using the leaving-one-out sampling. The best result that was achieved is an accuracy of 92% for all classes and an accuracy of 76% for Barrett's esophagus. These results show that the NBI technology can provide a good diagnosis support when used in a CAD system.

Prediction of Drug-Target Interactions and Drug Repositioning via Network-Based Inference

PubMed Central

Jiang, Jing; Lu, Weiqiang; Li, Weihua; Liu, Guixia; Zhou, Weixing; Huang, Jin; Tang, Yun

2012-01-01

Drug-target interaction (DTI) is the basis of drug discovery and design. It is time consuming and costly to determine DTI experimentally. Hence, it is necessary to develop computational methods for the prediction of potential DTI. Based on complex network theory, three supervised inference methods were developed here to predict DTI and used for drug repositioning, namely drug-based similarity inference (DBSI), target-based similarity inference (TBSI) and network-based inference (NBI). Among them, NBI performed best on four benchmark data sets. Then a drug-target network was created with NBI based on 12,483 FDA-approved and experimental drug-target binary links, and some new DTIs were further predicted. In vitro assays confirmed that five old drugs, namely montelukast, diclofenac, simvastatin, ketoconazole, and itraconazole, showed polypharmacological features on estrogen receptors or dipeptidyl peptidase-IV with half maximal inhibitory or effective concentration ranged from 0.2 to 10 µM. Moreover, simvastatin and ketoconazole showed potent antiproliferative activities on human MDA-MB-231 breast cancer cell line in MTT assays. The results indicated that these methods could be powerful tools in prediction of DTIs and drug repositioning. PMID:22589709

A 12-Year Analysis of Nonbattle Injury Among US Service Members Deployed to Iraq and Afghanistan.

PubMed

Le, Tuan D; Gurney, Jennifer M; Nnamani, Nina S; Gross, Kirby R; Chung, Kevin K; Stockinger, Zsolt T; Nessen, Shawn C; Pusateri, Anthony E; Akers, Kevin S

2018-05-30

Nonbattle injury (NBI) among deployed US service members increases the burden on medical systems and results in high rates of attrition, affecting the available force. The possible causes and trends of NBI in the Iraq and Afghanistan wars have, to date, not been comprehensively described. To describe NBI among service members deployed to Iraq and Afghanistan, quantify absolute numbers of NBIs and proportion of NBIs within the Department of Defense Trauma Registry, and document the characteristics of this injury category. In this retrospective cohort study, data from the Department of Defense Trauma Registry on 29 958 service members injured in Iraq and Afghanistan from January 1, 2003, through December 31, 2014, were obtained. Injury incidence, patterns, and severity were characterized by battle injury and NBI. Trends in NBI were modeled using time series analysis with autoregressive integrated moving average and the weighted moving average method. Statistical analysis was performed from January 1, 2003, to December 31, 2014. Primary outcomes were proportion of NBIs and the changes in NBI over time. Among 29 958 casualties (battle injury and NBI) analyzed, 29 003 were in men and 955 were in women; the median age at injury was 24 years (interquartile range, 21-29 years). Nonbattle injury caused 34.1% of total casualties (n = 10 203) and 11.5% of all deaths (206 of 1788). Rates of NBI were higher among women than among men (63.2% [604 of 955] vs 33.1% [9599 of 29 003]; P < .001) and in Operation New Dawn (71.0% [298 of 420]) and Operation Iraqi Freedom (36.3% [6655 of 18 334]) compared with Operation Enduring Freedom (29.0% [3250 of 11 204]) (P < .001). A higher proportion of NBIs occurred in members of the Air Force (66.3% [539 of 810]) and Navy (48.3% [394 of 815]) than in members of the Army (34.7% [7680 of 22 154]) and Marine Corps (25.7% [1584 of 6169]) (P < .001). Leading mechanisms of NBI included falls (2178 [21.3%]), motor vehicle crashes (1921 [18.8%]), machinery or equipment accidents (1283 [12.6%]), blunt objects (1107 [10.8%]), gunshot wounds (728 [7.1%]), and sports (697 [6.8%]), causing predominantly blunt trauma (7080 [69.4%]). The trend in proportion of NBIs did not decrease over time, remaining at approximately 35% (by weighted moving average) after 2006 and approximately 39% by autoregressive integrated moving average. Assuming stable battlefield conditions, the autoregressive integrated moving average model estimated that the proportion of NBIs from 2015 to 2022 would be approximately 41.0% (95% CI, 37.8%-44.3%). In this study, approximately one-third of injuries during the Iraq and Afghanistan wars resulted from NBI, and the proportion of NBIs was steady for 12 years. Understanding the possible causes of NBI during military operations may be useful to target protective measures and safety interventions, thereby conserving fighting strength on the battlefield.

Progress toward commissioning and plasma operation in NSTX-U

NASA Astrophysics Data System (ADS)

Ono, M.; Chrzanowski, J.; Dudek, L.; Gerhardt, S.; Heitzenroeder, P.; Kaita, R.; Menard, J. E.; Perry, E.; Stevenson, T.; Strykowsky, R.; Titus, P.; von Halle, A.; Williams, M.; Atnafu, N. D.; Blanchard, W.; Cropper, M.; Diallo, A.; Gates, D. A.; Ellis, R.; Erickson, K.; Hosea, J.; Hatcher, R.; Jurczynski, S. Z.; Kaye, S.; Labik, G.; Lawson, J.; LeBlanc, B.; Maingi, R.; Neumeyer, C.; Raman, R.; Raftopoulos, S.; Ramakrishnan, R.; Roquemore, A. L.; Sabbagh, S. A.; Sichta, P.; Schneider, H.; Smith, M.; Stratton, B.; Soukhanovskii, V.; Taylor, G.; Tresemer, K.; Zolfaghari, A.; The NSTX-U Team

2015-07-01

The National Spherical Torus Experiment-Upgrade (NSTX-U) is the most powerful spherical torus facility at PPPL, Princeton USA. The major mission of NSTX-U is to develop the physics basis for an ST-based Fusion Nuclear Science Facility (FNSF). The ST-based FNSF has the promise of achieving the high neutron fluence needed for reactor component testing with relatively modest tritium consumption. At the same time, the unique operating regimes of NSTX-U can contribute to several important issues in the physics of burning plasmas to optimize the performance of ITER. NSTX-U further aims to determine the attractiveness of the compact ST for addressing key research needs on the path toward a fusion demonstration power plant (DEMO). The upgrade will nearly double the toroidal magnetic field BT to 1 T at a major radius of R0 = 0.93 m, plasma current Ip to 2 MA and neutral beam injection (NBI) heating power to 14 MW. The anticipated plasma performance enhancement is a quadrupling of the plasma stored energy and near doubling of the plasma confinement time, which would result in a 5-10 fold increase in the fusion performance parameter nτ T. A much more tangential 2nd NBI system, with 2-3 times higher current drive efficiency compared to the 1st NBI system, is installed to attain the 100% non-inductive operation needed for a compact FNSF design. With higher fields and heating powers, the NSTX-U plasma collisionality will be reduced by a factor of 3-6 to help explore the favourable trend in transport towards the low collisionality FNSF regime. The NSTX-U first plasma is planned for the Summer of 2015, at which time the transition to plasma operations will occur.

Prediction of Helicobacter pylori status by conventional endoscopy, narrow-band imaging magnifying endoscopy in stomach after endoscopic resection of gastric cancer.

PubMed

Yagi, Kazuyoshi; Saka, Akiko; Nozawa, Yujiro; Nakamura, Atsuo

2014-04-01

To reduce the incidence of metachronous gastric carcinoma after endoscopic resection of early gastric cancer, Helicobacter pylori eradication therapy has been endorsed. It is not unusual for such patients to be H. pylori negative after eradication or for other reasons. If it were possible to predict H. pylori status using endoscopy alone, it would be very useful in clinical practice. To clarify the accuracy of endoscopic judgment of H. pylori status, we evaluated it in the stomach after endoscopic submucosal dissection (ESD) of gastric cancer. Fifty-six patients treated by ESD were enrolled. The diagnostic criteria for H. pylori status by conventional endoscopy and narrow-band imaging (NBI)-magnifying endoscopy were decided, and H. pylori status was judged by two endoscopists. Based on the H. pylori stool antigen test as a diagnostic gold standard, conventional endoscopy and NBI-magnifying endoscopy were compared for their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Interobserver agreement was assessed in terms of κ value. Interobserver agreement was moderate (0.56) for conventional endoscopy and substantial (0.77) for NBI-magnifying endoscopy. The sensitivity, specificity, PPV, and NPV were 0.79, 0.52, 0.70, and 0.63 for conventional endoscopy and 0.91, 0.83, 0.88, and 0.86 for NBI-magnifying endoscopy, respectively. Prediction of H. pylori status using NBI-magnifying endoscopy is practical, and interobserver agreement is substantial. © 2013 John Wiley & Sons Ltd.

Naphthalene bisimides asymmetrically and symmetrically N-substituted with triarylamine--comparison of spectroscopic, electrochemical, electronic and self-assembly properties.

PubMed

Rybakiewicz, Renata; Zapala, Joanna; Djurado, David; Nowakowski, Robert; Toman, Petr; Pfleger, Jiri; Verilhac, Jean-Marie; Zagorska, Malgorzata; Pron, Adam

2013-02-07

Two semiconducting naphthalene bisimides were comparatively studied: NBI-(TAA)(2), symmetrically N-substituted with triaryl amine and asymmetric NBI-TAA-Oc with triaryl amine and octyl N-substituents. Both compounds show very similar spectroscopic and redox properties but differ in their supramolecular organization. As evidenced by STM, in monolayers on HOPG they form ordered 2D structures, however of different packing patterns. NBI-(TAA)(2) does not form ordered 3D structures, yielding amorphous thin films whereas films of NBI-TAA-Oc are highly crystalline. DFT calculations predict the ionization potential (IP) of 5.22 eV and 5.18 eV for NBI-TAA-Oc and NBI-(TAA)(2), respectively, as well as the electron affinity values (EA) of -3.25 eV and -3.22 eV. These results are consistent with the cyclic voltammetry data which yield similar values of IP (5.20 eV and 5.19 eV) and somehow different values of EA (-3.80 eV and -3.83 eV). As judged from these data, both semiconductors should exhibit ambipolar behavior. Indeed, NBI-TAA-Oc is ambipolar, showing hole and electron mobilities of 4.5 × 10(-5) cm(2)/(V s) and of 2.6 × 10(-4) cm(2)/(V s), respectively, in the field effect transistor configuration. NBI-(TAA)(2) is not ambipolar and yields field effect only in the p-channel configuration. This different behavior is rationalized on the basis of structural factors.

Ion source development for a photoneutralization based NBI system for fusion reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simonin, A.; Esch, H. P. L. de; Garibaldi, P.

2015-04-08

The next step after ITER is to demonstrate the viability and generation of electricity by a future fusion reactor (DEMO). The specifications required to operate an NBI system on DEMO are very demanding. The system has to provide a very high level of power and energy, ~100MW of D° beam at 1MeV, including high wall-plug efficiency (η > 60%). For this purpose, a new injector concept, called Siphore, is under investigation between CEA and French universities. Siphore is based on the stripping of the accelerated negative ions by photo-detachment provided by several Fabry-Perot cavities (3.5MW of light power per cavity)more » implemented along the D{sup −} beam. The beamline is designed to be tall and narrow in order that the photon flux overlaps the entire negative ion beam. The paper will describe the present R and D at CEA which addresses the development of an ion source and pre-accelerator prototypes for Siphore, the main goal being to produce an intense negative ion beam sheet. The negative ion source Cybele is based on a magnetized plasma column where hot electrons are emitted from the source center. Parametric studies of the source are performed using Langmuir probes in order to characterize the plasma and to compare with numerical models being developed in French universities.« less

Code-division multiple-access protocol for active RFID systems

NASA Astrophysics Data System (ADS)

Mazurek, Gustaw; Szabatin, Jerzy

2008-01-01

Most of the Radio Frequency Identification (RFID) systems operating in HF and UHF bands employ narrowband modulations (FSK or ASK) with Manchester coding. However, these simple transmission schemes are vulnerable to narrowband interference (NBI) generated by other radio systems working in the same frequency band, and also suffer from collision problem and need special anti-collision procedures. This becomes especially important when operating in a noisy, crowded industrial environment. In this paper we show the performance of RFID system with DS-CDMA transmission in comparison to a standard system with FSK modulation defined in ISO 18000-7. Our simulation results show that without any bandwidth expansion the immunity against NBI can be improved by 8 dB and the system capacity can be 7 times higher when using DS-CDMA transmission instead of FSK modulation with Manchester coding.

Randomized, controlled trial of standard-definition white-light, high-definition white-light, and narrow-band imaging colonoscopy for the detection of colon polyps and prediction of polyp histology.

PubMed

Rastogi, Amit; Early, Dayna S; Gupta, Neil; Bansal, Ajay; Singh, Vikas; Ansstas, Michael; Jonnalagadda, Sreenivasa S; Hovis, Christine E; Gaddam, Srinivas; Wani, Sachin B; Edmundowicz, Steven A; Sharma, Prateek

2011-09-01

Missing adenomas and the inability to accurately differentiate between polyp histology remain the main limitations of standard-definition white-light (SD-WL) colonoscopy. To compare the adenoma detection rates of SD-WL with those of high-definition white-light (HD-WL) and narrow-band imaging (NBI) as well as the accuracy of predicting polyp histology. Multicenter, prospective, randomized, controlled trial. Two academic medical centers in the United States. Subjects undergoing screening or surveillance colonoscopy. Subjects were randomized to undergo colonoscopy with one of the following: SD-WL, HD-WL, or NBI. The proportion of subjects detected with adenomas, adenomas detected per subject, and the accuracy of predicting polyp histology real time. A total of 630 subjects were included. The proportion of subjects with adenomas was 38.6% with SD-WL compared with 45.7% with HD-WL and 46.2% with NBI (P = .17 and P = .14, respectively). Adenomas detected per subject were 0.69 with SD-WL compared with 1.12 with HD-WL and 1.13 with NBI (P = .016 and P = .014, respectively). HD-WL and NBI detected more subjects with flat and right-sided adenomas compared with SD-WL (all P values <.005). NBI had a superior sensitivity (90%) and accuracy (82%) to predict adenomas compared with SD-WL and HD-WL (all P values <.005). Academic medical centers with experienced endoscopists. There was no difference in the proportion of subjects with adenomas detected with SD-WL, HD-WL, and NBI. However, HD-WL and NBI detected significantly more adenomas per subject (>60%) compared with SD-WL. NBI had the highest accuracy in predicting adenomas in real time during colonoscopy. ( NCT 00614770.). Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

CNN-SVM for Microvascular Morphological Type Recognition with Data Augmentation.

PubMed

Xue, Di-Xiu; Zhang, Rong; Feng, Hui; Wang, Ya-Lei

2016-01-01

This paper focuses on the problem of feature extraction and the classification of microvascular morphological types to aid esophageal cancer detection. We present a patch-based system with a hybrid SVM model with data augmentation for intraepithelial papillary capillary loop recognition. A greedy patch-generating algorithm and a specialized CNN named NBI-Net are designed to extract hierarchical features from patches. We investigate a series of data augmentation techniques to progressively improve the prediction invariance of image scaling and rotation. For classifier boosting, SVM is used as an alternative to softmax to enhance generalization ability. The effectiveness of CNN feature representation ability is discussed for a set of widely used CNN models, including AlexNet, VGG-16, and GoogLeNet. Experiments are conducted on the NBI-ME dataset. The recognition rate is up to 92.74% on the patch level with data augmentation and classifier boosting. The results show that the combined CNN-SVM model beats models of traditional features with SVM as well as the original CNN with softmax. The synthesis results indicate that our system is able to assist clinical diagnosis to a certain extent.

Diagnosis of early gastric cancer using narrow band imaging and acetic acid

PubMed Central

Matsuo, Ken; Takedatsu, Hidetoshi; Mukasa, Michita; Sumie, Hiroaki; Yoshida, Hikaru; Watanabe, Yasutomo; Akiba, Jun; Nakahara, Keita; Tsuruta, Osamu; Torimura, Takuji

2015-01-01

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers (EGCs) could precisely predict the histological type. METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular (MV) and mucosal surface (MS) patterns of depressed-type EGCs using magnifying endoscopy (ME) with narrow-band imaging (NBI) (NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME (EME) images obtained from the same angle. RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma (25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma (18/23, 78.3%). However, 42 of the 90 (46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33 (81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90 (84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME. CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressed-type EGC. PMID:25632201

Clinical usefulness of magnifying endoscopy for non-ampullary duodenal tumors.

PubMed

Mizumoto, Takeshi; Sanomura, Yoji; Tanaka, Shinji; Kuroki, Kazutoshi; Kurihara, Mio; Yoshifuku, Yoshikazu; Oka, Shiro; Arihiro, Koji; Shimamoto, Fumio; Chayama, Kazuaki

2017-04-01

Study aims  This study aimed to investigate the clinical usefulness of magnifying endoscopy (ME) for non-ampullary duodenal tumors. Patients and methods  We enrolled 103 consecutive patients with non-ampullary duodenal tumors that were observed by ME with narrow-band imaging (ME-NBI) and had pit pattern analysis before endoscopic resection at Hiroshima University Hospital before December 2014. ME-NBI images were classified as Type B or Type C according to the Hiroshima classification, and pit patterns were classified as regular or irregular. We studied the clinicopathological features and diagnoses with ME-NBI and pit pattern analyses according to the Vienna classification (category 3: 73 patients; category 4: 30 patients). Results  Category 4 lesions were significantly larger than category 3 lesions. According to ME-NBI images, category 4 Type C lesions (83 %) were significantly more common than category 4 Type B lesions (17 %). According to pit pattern analyses, category 4 irregular lesions 4 (77 %) were significantly more common than category 4 regular lesions (23 %). The accuracies of using Type C ME-NBI images and irregular pit patterns to diagnose category 4 lesions were 87 % and 84 %, the sensitivities were 83 % and 77 %, and the specificities were 89 % and 88 %, respectively. There was no significant difference between ME-NBI and pit pattern analyses for diagnosing the histologic grade of non-ampullary duodenal tumors. Conclusion  Our study showed that ME-NBI and pit pattern analysis had equivalent abilities to determine the histologic grade of non-ampullary duodenal tumors. ME-NBI may be more useful because it is a simple, less time-consuming procedure.

Low and High Molecular Mass Dithienopyrrole-Naphthalene Bisimide Donor-Acceptor Compounds: Synthesis, Electrochemical and Spectroelectrochemical Behaviour.

PubMed

Rybakiewicz, Renata; Glowacki, Eric D; Skorka, Lukasz; Pluczyk, Sandra; Zassowski, Pawel; Apaydin, Dogukan Hazar; Lapkowski, Mieczyslaw; Zagorska, Malgorzata; Pron, Adam

2017-02-24

Two low molecular weight electroactive donor-acceptor-donor (DAD)-type molecules are reported, namely naphthalene bisimide (NBI) symmetrically core-functionalized with dithienopyrrole (NBI-(DTP) 2 ) and an asymmetric core-functionalized naphthalene bisimide with dithienopyrrole (DTP) substituent on one side and 2-ethylhexylamine on the other side (NBI-DTP-NHEtHex). Both compounds are characterized by low optical bandgaps (1.52 and 1.65 eV, respectively). NBI-(DTP) 2 undergoes oxidative electropolymerization giving the electroactive polymer of ambipolar character. Its two-step reversible reduction and oxidation is corroborated by complementary EPR and UV/Vis-NIR spectroelectrochemical investigations. The polymer turned out to be electrochemically active not only in aprotic solvents but also in aqueous electrolytes, showing a distinct photocathodic current attributed to proton reduction. Additionally, poly(NBI-(DTP) 2 ) was successfully tested as a photodiode material. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endoscopic tri-modal imaging for detection of early neoplasia in Barrett's oesophagus: a multi-centre feasibility study using high-resolution endoscopy, autofluorescence imaging and narrow band imaging incorporated in one endoscopy system.

PubMed

Curvers, W L; Singh, R; Song, L-M Wong-Kee; Wolfsen, H C; Ragunath, K; Wang, K; Wallace, M B; Fockens, P; Bergman, J J G H M

2008-02-01

To investigate the diagnostic potential of endoscopic tri-modal imaging and the relative contribution of each imaging modality (i.e. high-resolution endoscopy (HRE), autofluorescence imaging (AFI) and narrow-band imaging (NBI)) for the detection of early neoplasia in Barrett's oesophagus. Prospective multi-centre study. Tertiary referral centres. 84 Patients with Barrett's oesophagus. The Barrett's oesophagus was inspected with HRE followed by AFI. All lesions detected with HRE and/or AFI were subsequently inspected in detail by NBI for the presence of abnormal mucosal and/or microvascular patterns. Biopsies were obtained from all suspicious lesions for blinded histopathological assessment followed by random biopsies. (1) Number of patients with early neoplasia diagnosed by HRE and AFI; (2) number of lesions with early neoplasia detected with HRE and AFI; and (3) reduction of false positive AFI findings after NBI. Per patient analysis: AFI identified all 16 patients with early neoplasia identified with HRE and detected an additional 11 patients with early neoplasia that were not identified with HRE. In three patients no abnormalities were seen but random biopsies revealed HGIN. After HRE inspection, AFI detected an additional 102 lesions; 19 contained HGIN/EC (false positive rate of AFI after HRE: 81%). Detailed inspection with NBI reduced this false positive rate to 26%. In this international multi-centre study, the addition of AFI to HRE increased the detection of both the number of patients and the number of lesions with early neoplasia in patients with Barrett's oesophagus. The false positive rate of AFI was reduced after detailed inspection with NBI.

The Clinical Research Office of the Endourological Society (CROES) Multicentre Randomised Trial of Narrow Band Imaging-Assisted Transurethral Resection of Bladder Tumour (TURBT) Versus Conventional White Light Imaging-Assisted TURBT in Primary Non-Muscle-invasive Bladder Cancer Patients: Trial Protocol and 1-year Results.

PubMed

Naito, Seiji; Algaba, Ferran; Babjuk, Marko; Bryan, Richard T; Sun, Ying-Hao; Valiquette, Luc; de la Rosette, Jean

2016-09-01

White light (WL) is the established imaging modality for transurethral resection of bladder tumour (TURBT). Narrow band imaging (NBI) is a promising addition. To compare 12-mo recurrence rates following TURBT using NBI versus WL guidance. The Clinical Research Office of the Endourological Society (CROES) conducted a prospective randomised single-blind multicentre study. Patients with primary non-muscle-invasive bladder cancer (NMIBC) were randomly assigned 1:1 to TURBT guided by NBI or WL. TURBT for NMIBC using NBI or WL. Twelve-month recurrence rates were compared by chi-square tests and survival analyses. Of the 965 patients enrolled in the study, 481 patients underwent WL-assisted TURBT and 484 patients received NBI-assisted TURBT. Of these, 294 and 303 patients, respectively, completed 12-mo follow-up, with recurrence rates of 27.1% and 25.4%, respectively (p=0.585, intention-to-treat [ITT] analysis). In patients at low risk for disease recurrence, recurrence rates at 12 mo were significantly higher in the WL group compared with the NBI group (27.3% vs 5.6%; p=0.002, ITT analysis). Although TURBT took longer on average with NBI plus WL compared with WL alone (38.1 vs 35.0min, p=0.039, ITT; 39.1 vs 35.7min, p=0.047, per protocol [PP] analysis), lesions were significantly more often visible with NBI than with WL (p=0.033). Frequency and severity of adverse events were similar in both treatment groups. Possible limitations were lack of uniformity of surgical resection, data on smoking status, central pathology review, and specific data regarding adjuvant intravesical instillation therapy. NBI and WL guidance achieved similar overall recurrence rates 12 mo after TURBT in patients with NMIBC. NBI-assisted TURBT significantly reduced the likelihood of disease recurrence in low-risk patients. Use of a narrow band imaging technique might provide greater detection of bladder tumours and subsequent treatment leading to reduced recurrence in low-risk patients. Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Overview of C-2W Field-Reversed Configuration Experimental Program

NASA Astrophysics Data System (ADS)

Gota, H.; Binderbauer, M. W.; Tajima, T.; Putvinski, S.; Tuszewski, M.; Dettrick, S.; Korepanov, S.; Romero, J.; Smirnov, A.; Song, Y.; Thompson, M. C.; van Drie, A.; Yang, X.; Ivanov, A. A.; TAE Team

2017-10-01

Tri Alpha Energy's research has been devoted to producing a high temperature, stable, long-lived field-reversed configuration (FRC) plasma state by neutral-beam injection (NBI) and edge biasing/control. C-2U experiments have demonstrated drastic improvements in particle and energy confinement properties of FRC's, and the plasma performance obtained via 10 MW NBI has achieved plasma sustainment of up to 5 ms and plasma (diamagnetism) lifetimes of 10 + ms. The emerging confinement scaling, whereby electron energy confinement time is proportional to a positive power of the electron temperature, is very attractive for higher energy plasma confinement; accordingly, verification of the observed Te scaling law will be a key future research objective. The new experimental device, C-2W (now also called ``Norman''), has the following key subsystem upgrades from C-2U: (i) higher injected power, optimum energies, and extended pulse duration of the NBI system; (ii) installation of inner divertors with upgraded edge-biasing systems; (iii) fast external equilibrium/mirror-coil current ramp-up capability; and (iv) installation of trim/saddle coils for active feedback control of the FRC plasma. This paper will review highlights of the C-2W program.

Electron cyclotron plasma startup in the GDT experiment

NASA Astrophysics Data System (ADS)

Yakovlev, D. V.; Shalashov, A. G.; Gospodchikov, E. D.; Solomakhin, A. L.; Savkin, V. Ya.; Bagryansky, P. A.

2017-01-01

We report on a new plasma startup scenario in the gas dynamic trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) plasma heating system fires into a sufficiently dense plasma target (‘seed plasma’), which is commonly supplied by an arc plasma generator. In the reported experiments, a different approach to seed plasma generation is explored. One of the channels of the electron cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of plasma to a level suitable for NBI capture. After a short transition of approximately 1 ms the discharge becomes essentially similar to a standard one initiated by the plasma gun. This paper presents the discharge scenario and experimental data on the seed plasma evolution during ECRH, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of the consequent high-power NBI discharge are studied and differences from the conventional scenario are discussed. A theoretical model describing the ECR breakdown and the seed plasma accumulation in a large-scale mirror trap is developed on the basis of the GDT experiment.

A Proposal for a Dimensional Classification System Based on the Shared Features of the DSM-IV Anxiety and Mood Disorders: Implications for Assessment and Treatment

PubMed Central

Brown, Timothy A.; Barlow, David H.

2010-01-01

A wealth of evidence attests to the extensive current and lifetime diagnostic comorbidity of the DSM-IV anxiety and mood disorders. Research has shown that the considerable cross-sectional covariation of DSM-IV emotional disorders is accounted for by common higher-order dimensions such as neuroticism/behavioral inhibition (N/BI) and low positive affect/behavioral activation. Longitudinal studies have indicated that the temporal covariation of these disorders can be explained by changes in N/BI and in some cases, initial levels of N/BI are predictive of the temporal course of emotional disorders. Moreover, the marked phenotypal overlap of the DSM-IV anxiety and mood disorder constructs is a frequent source of diagnostic unreliability (e.g., temporal overlap in the shared features of generalized anxiety disorder and mood disorders, situation specificity of panic attacks in panic disorder and specific phobia). Although dimensional approaches have been considered as a method to address the drawbacks associated with the extant prototypical nosology (e.g., inadequate assessment of individual differences in disorder severity), these proposals do not reconcile key problems in current classification such as modest reliability and high comorbidity. The current paper considers an alternative approach that emphasizes empirically supported common dimensions of emotional disorders over disorder-specific criteria sets. The selection and assessment of these dimensions are discussed along with how these methods could be implemented to promote more reliable and valid diagnosis, prognosis, and treatment planning. For instance, the advantages of this classification system are discussed in context of current transdiagnostic treatment protocols that are efficaciously applied to a variety of disorders by targeting their shared features. PMID:19719339

A randomised tandem colonoscopy trial of narrow band imaging versus white light examination to compare neoplasia miss rates.

PubMed

Kaltenbach, T; Friedland, S; Soetikno, R

2008-10-01

Colonoscopy, the "gold standard" screening test for colorectal cancer (CRC), has known diagnostic limitations. Advances in endoscope technology have focused on improving mucosal visualisation. In addition to increased angle of view and resolution features, recent colonoscopes have non-white-light optics, such as narrow band imaging (NBI), to enhance image contrast. We aimed to study the neoplasia diagnostic characteristics of NBI, by comparing the neoplasm miss rate when the colonoscopy was performed under NBI versus white light (WL). Randomised controlled trial. US Veterans hospital. Elective colonoscopy adults. We randomly assigned patients to undergo a colonoscopic examination using NBI or WL. All patients underwent a second examination using WL, as the reference standard. The primary end point was the difference in the neoplasm miss rate, and secondary outcome was the neoplasm detection rate. In 276 tandem colonoscopy patients, there was no significant difference of miss or detection rates between NBI or WL colonoscopy techniques. Of the 135 patients in the NBI group, 17 patients (12.6%; 95% confidence interval (CI) 7.5 to 19.4%) had a missed neoplasm, as compared with 17 of the 141 patients (12.1%; 95% CI 7.2 to 18.6%) in the WL group, with a miss rate risk difference of 0.5% (95% CI -7.2 to 8.3). 130 patients (47%) had at least one neoplasm. Missed lesions with NBI showed similar characteristics to those missed with WL. All missed neoplasms were tubular adenomas, the majority (78%) was < or = 5 mm and none were larger than 1 cm (one-sided 95% CI up to 1%). Nonpolypoid lesions represented 35% (13/37) of missed neoplasms. NBI did not improve the colorectal neoplasm miss rate compared to WL; the miss rate for advanced adenomas was less than 1% and for all adenomas was 12%. The neoplasm detection rates were similar high using NBI or WL; almost a half the study patients had at least one adenoma. Clinicaltrials.gov identifier: NCT00628147.

Backscatter measurements for NIF ignition targets (invited).

PubMed

Moody, J D; Datte, P; Krauter, K; Bond, E; Michel, P A; Glenzer, S H; Divol, L; Niemann, C; Suter, L; Meezan, N; MacGowan, B J; Hibbard, R; London, R; Kilkenny, J; Wallace, R; Kline, J L; Knittel, K; Frieders, G; Golick, B; Ross, G; Widmann, K; Jackson, J; Vernon, S; Clancy, T

2010-10-01

Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

Fast particle confinement with optimized coil currents in the W7-X stellarator

NASA Astrophysics Data System (ADS)

Drevlak, M.; Geiger, J.; Helander, P.; Turkin, Y.

2014-07-01

One of the principal goals of the W7-X stellarator is to demonstrate good confinement of energetic ions at finite β. This confinement, however, is sensitive to the magnetic field configuration and is thus vulnerable to design modifications of the coil geometry. The collisionless drift orbit losses for 60 keV protons in W7-X are studied using the ANTS code. Particles in this energy range will be produced by the neutral beam injection (NBI) system being constructed for W7-X, and are particularly important because protons at this energy accurately mimick the behaviour of 3.5 MeV α-particles in a HELIAS reactor. To investigate the possibility of improved fast particle confinement, several approaches to adjust the coil currents (5 main field coil currents +2 auxiliary coil currents) were explored. These strategies include simple rules of thumb as well as computational optimization of various properties of the magnetic field. It is shown that significant improvement of collisionless fast particle confinement can be achieved in W7-X for particle populations similar to α particles produced in fusion reactions. Nevertheless, the experimental goal of demonstrating confinement improvement with rising plasma pressure using an NBI-generated population appears to be difficult based on optimization of the coil currents only. The principal reason for this difficulty is that the NBI deposition profile is broader than the region of good fast-ion confinement around the magnetic axis.

Stability and confinement improvement of an oblate field-reversed configuration by using neutral beam injection

NASA Astrophysics Data System (ADS)

T., Ii; Inomoto, M.; Gi, K.; Umezawa, T.; Ito, T.; Kadowaki, K.; Kaminou, Y.; Ono, Y.

2013-07-01

A low-energy, high-current neutral beam injection (NBI) was applied to an oblate field-reversed configuration (FRC) for the first time. The NB fast ions reduce growth rates of low-n modes dangerous for the oblate FRC, extending the FRC lifetime by a factor of 1.2. The reduced loss power of 5 MW is much higher than the NBI power of 0.5 MW, indicating that the NBI not only heats the FRC plasma but also improves its stability and transport properties. The NBI also maintains higher pressure and current density profiles of the FRC, improving its flux and energy decay times by a factor of 2.

Oblate Field-Reversed Configuration Experiments with Neutral Beam Injection

NASA Astrophysics Data System (ADS)

T., II; Gi, K.; Umezawa, T.; Inomoto, M.; Ono, Y.

2011-11-01

The effect of energetic beam ions on oblate Field-Reversed Configurations (FRCs) has been studied experimentally in the TS-4 plasma merging device. In order to examine its kinetic effects, we developed an economical pulsed Neutral Beam Injection (NBI) system by using a washer gun plasma source and finally attained the beam power of 0.6 MW (15 kV, 40 A) for its pulse length of 0.5 ms, longer than the FRC lifetime in TS-4. The Monte Carlo simulation indicates that the tangential NB ions of 15 keV are trapped between the magnetic axis and the separatrix. We found that two merging high-s (s is plasma size normalized by ion gyroradius) hydrogen spheromaks with opposite helicities relaxed into the large scale FRC with poloidal flux as high as 15 mWb under the assistance of the NBI. Without the assistance of NBI, however, they did not relax to an FRC but to another spheromak. These facts suggest some ion kinetic effects such as toroidal ion flow are essential to FRC stability. Recently, two new NB sources with acceleration voltage and current of 15 kV and 20 A were installed on the TS-4 device on the midplane for tangential injection, increasing the beam power over 1 MW. We will start the upgraded FRC experiments using the 1 MW NBI for ion flow control.

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy.

PubMed

Kikuchi, D; Iizuka, T; Hoteya, S; Nomura, K; Kuribayashi, Y; Toba, T; Tanaka, M; Yamashita, S; Furuhata, T; Matsui, A; Mitani, T; Inoshita, N; Kaise, M

2017-11-01

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Simplified criteria for diagnosing superficial esophageal squamous neoplasms using Narrow Band Imaging magnifying endoscopy

PubMed Central

Dobashi, Akira; Goda, Kenichi; Yoshimura, Noboru; Ohya, Tomohiko R; Kato, Masayuki; Sumiyama, Kazuki; Matsushima, Masato; Hirooka, Shinichi; Ikegami, Masahiro; Tajiri, Hisao

2016-01-01

AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma (SESCC) on Narrow Band Imaging combined with magnifying endoscopy (NBI-ME). METHODS This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopists detected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: “intervascular background coloration”; “proliferation of intrapapillary capillary loops (IPCL)”; and “dilation”, “tortuosity”, “change in caliber”, and “various shapes (VS)” of IPCLs (i.e., Inoue’s tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue’s criteria. RESULTS Fifty-four lesions (65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC (P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue’s tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue’s tetrad criteria, respectively. CONCLUSION The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBI-ME. PMID:27895406

The hydrogen isotope ratio in W7-AS during deuterium NBI heating

NASA Astrophysics Data System (ADS)

Zebisch, P.; Taglauer, E.; W7-AS Team; NBI Team

1999-04-01

With a so-called sniffer probe the fraction of hydrogen during discharges with deuterium NBI heating was studied in the plasma edge of the stellarator W7-AS. As expected, the ratios were significantly lower than in discharges with hydrogen NBI heating but were higher than those in discharges with only ECRH. An examination of the possible reasons for this increase concludes that it is not only partially caused by the direct influence of neutral injection but also depends on the energy content of the plasma determined by the heating power and the confinement time. Of course, the isotope ratio also depends on the starting conditions, i.e. the isotope ratio before the onset of NBI.

A series of coordination polymers constructed from R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands: Syntheses, structures and fluorescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Yong-Hong, E-mail: zhou21921@sina.com; Zhou, Xu-Wan; Zhou, Su-Rong

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn{sub 2}Na(sip){sub 2}(bpp){sub 3}(Hbpp)(H{sub 2}O){sub 2}]·8H{sub 2}O (1), [Cd{sub 3}(sip){sub 2}(nbi){sub 6}(H{sub 2}O){sub 2}]·7H{sub 2}O (2), [Zn(sip)(nbi){sub 2}(H{sub 2}O)]·Hnbi·3H{sub 2}O (3), [Cd(hip)(nbi){sub 2}(H{sub 2}O)]·nbi·5H{sub 2}O (4), [Cd{sub 2}(nip){sub 2}(nbi){sub 2}(H{sub 2}O){sub 2}]·DMF (5), and [Cu(nip)(nbi)(H{sub 2}O){sub 2}]·H{sub 2}O (6) (H{sub 3}sip=5-sulfoisophthalic acid, H{sub 2}hip=5-hydroxylisophthalic acid, H{sub 2}nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through Omore » atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip{sup 3−} anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3–5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip{sup 2−} ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied. - Graphical abstract: A series of Cd(II)/Zn(II)/ Cu(II) coordination polymers based on R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands have been synthesized under hydrothermal conditions and structurally characterized. Photoluminescent properties have been discussed. - Highlights: • Six coordination polymers were synthesized based on mixed-ligand strategy. • The polycarboxylate acids play a crucial role in determining the final structures. • Each complex shows diverse structures and different supramolecular interactions.« less

The role of high-resolution endoscopy and narrow-band imaging in the evaluation of upper GI neoplasia in familial adenomatous polyposis.

PubMed

Lopez-Ceron, Maria; van den Broek, Frank J C; Mathus-Vliegen, Elisabeth M; Boparai, Karam S; van Eeden, Susanne; Fockens, Paul; Dekker, Evelien

2013-04-01

The Spigelman classification stratifies cancer risk in familial adenomatous polyposis (FAP) patients with duodenal adenomatosis. High-resolution endoscopy (HRE) and narrow-band imaging (NBI) may identify lesions at high risk. To compare HRE and NBI for the detection of duodenal and gastric polyps and to characterize duodenal adenomas harboring advanced histology with HRE and NBI. Prospective, nonrandomized, comparative study. Retrospective image evaluation study. Tertiary-care center. Thirty-seven FAP patients undergoing surveillance upper endoscopies. HRE endoscopy was followed by NBI. The number of gastric polyps and Spigelman staging were compared. Duodenal polyp images were systematically reviewed in a learning and validation phase. Number of gastric and duodenal polyps detected by HRE and NBI and prevalence of specific endoscopic features in duodenal adenomas with advanced histology. NBI did not identify additional gastric polyps but detected more duodenal adenomas in 16 examinations, resulting in upgrades of the Spigelman stage in 2 cases (4.4%). Pictures of 168 duodenal adenomas (44% advanced histology) were assessed. In the learning phase, 3 endoscopic features were associated with advanced histology: white color, enlarged villi, and size ≥1 cm. Only size ≥1 cm was confirmed in the validation phase (odds ratio 3.0; 95% confidence interval, 1.2-7.4). Nonrandomized study, scant number of high-grade dysplasia adenomas. Inspection with NBI did not lead to a clinically relevant upgrade in the Spigelman classification and did not improve the detection of gastric polyps in comparison with HRE. The only endoscopic feature that predicted advanced histology of a duodenal adenoma was size ≥1 cm. Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Didactic training vs. computer-based self-learning in the prediction of diminutive colon polyp histology by trainees: a randomized controlled study.

PubMed

Khan, Taimur; Cinnor, Birtukan; Gupta, Neil; Hosford, Lindsay; Bansal, Ajay; Olyaee, Mojtaba S; Wani, Sachin; Rastogi, Amit

2017-12-01

Background and study aim  Experts can accurately predict diminutive polyp histology, but the ideal method to train nonexperts is not known. The aim of the study was to compare accuracy in diminutive polyp histology characterization using narrow-band imaging (NBI) between participants undergoing classroom didactic training vs. computer-based self-learning. Participants and methods  Trainees at two institutions were randomized to classroom didactic training or computer-based self-learning. In didactic training, experienced endoscopists reviewed a presentation on NBI patterns for adenomatous and hyperplastic polyps and 40 NBI videos, along with interactive discussion. The self-learning group reviewed the same presentation of 40 teaching videos independently, without interactive discussion. A total of 40 testing videos of diminutive polyps under NBI were then evaluated by both groups. Performance characteristics were calculated by comparing predicted and actual histology. Fisher's exact test was used and P  < 0.05 was considered significant. Results  A total of 17 trainees participated (8 didactic training and 9 self-learning). A larger proportion of polyps were diagnosed with high confidence in the classroom group (66.5 % vs. 50.8 %; P  < 0.01), although sensitivity (86.9 % vs. 95.0 %) and accuracy (85.7 % vs. 93.9 %) of high-confidence predictions were higher in the self-learning group. However, there was no difference in overall accuracy of histology characterization (83.4 % vs. 87.2 %; P  = 0.19). Similar results were noted when comparing sensitivity and specificity between the groups. Conclusion  The self-learning group showed results on a par with or, for high-confidence predictions, even slightly superior to classroom didactic training for predicting diminutive polyp histology. This approach can help in widespread training and clinical implementation of real-time polyp histology characterization. © Georg Thieme Verlag KG Stuttgart · New York.

Long pulse high performance plasma scenario development for the National Spherical Torus Experiment

NASA Astrophysics Data System (ADS)

Kessel, C. E.; Bell, R. E.; Bell, M. G.; Gates, D. A.; Kaye, S. M.; LeBlanc, B. P.; Menard, J. E.; Phillips, C. K.; Synakowski, E. J.; Taylor, G.; Wilson, R.; Harvey, R. W.; Mau, T. K.; Ryan, P. M.; Sabbagh, S. A.

2006-05-01

The National Spherical Torus Experiment [Ono et al., Nucl. Fusion, 44, 452 (2004)] is targeting long pulse high performance, noninductive sustained operations at low aspect ratio, and the demonstration of nonsolenoidal startup and current rampup. The modeling of these plasmas provides a framework for experimental planning and identifies the tools to access these regimes. Simulations based on neutral beam injection (NBI)-heated plasmas are made to understand the impact of various modifications and identify the requirements for (1) high elongation and triangularity, (2) density control to optimize the current drive, (3) plasma rotation and/or feedback stabilization to operate above the no-wall β limit, and (4) electron Bernstein waves (EBW) for off-axis heating/current drive (H/CD). Integrated scenarios are constructed to provide the transport evolution and H/CD source modeling, supported by rf and stability analyses. Important factors include the energy confinement, Zeff, early heating/H mode, broadening of the NBI-driven current profile, and maintaining q(0) and qmin>1.0. Simulations show that noninductive sustained plasmas can be reached at IP=800 kA, BT=0.5 T, κ≈2.5, βN⩽5, β⩽15%, fNI=92%, and q(0)>1.0 with NBI H/CD, density control, and similar global energy confinement to experiments. The noninductive sustained high β plasmas can be reached at IP=1.0 MA, BT=0.35 T, κ≈2.5, βN⩽9, β⩽43%, fNI=100%, and q(0)>1.5 with NBI H/CD and 3.0 MW of EBW H/CD, density control, and 25% higher global energy confinement than experiments. A scenario for nonsolenoidal plasma current rampup is developed using high harmonic fast wave H/CD in the early low IP and low Te phase, followed by NBI H/CD to continue the current ramp, reaching a maximum of 480 kA after 3.4 s.

Terahertz conductivity of the highly mismatched amorphous alloy, GaNBi

NASA Astrophysics Data System (ADS)

Vaisakh, C. P.; Foxon, C. T.; Novikov, S. V.; Kini, R. N.

2017-12-01

We report terahertz optical conductivity measurements of the highly mismatched alloy, GaNBi. We find that in these amorphous GaNBi epilayers grown using plasma assisted molecular beam epitaxy, the optical conductivity is enhanced in the samples grown at higher gallium beam equivalent pressure (BEP). The optical conductivity spectra in these pseudo-amorphous epilayers follow a Drude-Smith behaviour due to charge confinement effects. The direct current conductivity in the epilayers grown at the highest Ga BEP (3.1 × 10-7 Torr) show an increase of three orders of magnitude compared to the one grown at the lowest Ga BEP (2.0 × 10-7 Torr). Our measurements suggests a percolative transition from an insulating nature in the GaNBi epilayers grown at low Ga BEP to a highly conducting phase in the epilayers grown at high Ga BEP.

Probing RFP Density Limits and the Interaction of Pellet Fueling and NBI Heating on MST

NASA Astrophysics Data System (ADS)

Caspary, K. J.; Chapman, B. E.; Anderson, J. K.; Limbach, S. T.; Oliva, S. P.; Sarff, J. S.; Waksman, J.; Combs, S. K.; Foust, C. R.

2013-10-01

Pellet fueling on MST has previously achieved Greenwald fractions of up to 1.5 in 200 kA improved confinement discharges. Additionally, pellet fueling to densities above the Greenwald limit in 200 kA standard discharges resulted in early termination of the plasma, but pellet size was insufficient to exceed the limit for higher current discharges. To this end, the pellet injector on MST has been upgraded to increase the maximum fueling capability by increasing the size of the pellet guide tubes, which constrain the lateral motion of the pellet in flight, to accommodate pellets of up to 4.0 mm in diameter. These 4.0 mm pellets are capable of triggering density limit terminations for MST's peak current of 600 kA. An unexpected improvement in the pellet speed and mass control was also observed compared to the smaller diameter pellets. Exploring the effect of increased density on NBI particle and heat deposition shows that for MST's 1 MW tangential NBI, core deposition of 25 keV neutrals is optimized for densities of 2-3 × 1019 m-3. This is key for beta limit studies in pellet fueled discharges with improved confinement where maximum NBI heating is desired. An observed toroidal deflection of pellets injected into NBI heated discharges is consistent with asymmetric ablation due to the fast ion population. In 200 kA improved confinement plasmas with NBI heating, pellet fueling has achieved a Greenwald fraction of 2.0. Work supported by US DoE.

Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

DOE PAGES

Yamada, Masaaki

2016-01-01

This study briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactormore » program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.« less

Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

NASA Astrophysics Data System (ADS)

Yamada, Masaaki

2016-03-01

This paper briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactor program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.

Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Masaaki

2016-03-25

This paper briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactormore » program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.« less

Scintillator-based fast ion loss measurements in the EAST.

PubMed

Chang, J F; Isobe, M; Ogawa, K; Huang, J; Wu, C R; Xu, Z; Jin, Z; Lin, S Y; Hu, L Q

2016-11-01

A new scintillator-based fast ion loss detector (FILD) has been installed on Experimental Advanced Superconducting Tokamak (EAST) to investigate the fast ion loss behavior in high performance plasma with neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). A two dimensional 40 mm × 40 mm scintillator-coated (ZnS:Ag) stainless plate is mounted in the front of the detector, capturing the escaping fast ions. Photons from the scintillator plate are imaged with a Phantom V2010 CCD camera. The lost fast ions can be measured with the pitch angle from 60° to 120° and the gyroradius from 10 mm to 180 mm. This paper will describe the details of FILD diagnostic on EAST and describe preliminary measurements during NBI and ICRH heating.

Using narrow-band imaging with conventional hysteroscopy increases the detection of chronic endometritis in abnormal uterine bleeding and postmenopausal bleeding.

PubMed

Ozturk, Mustafa; Ulubay, Mustafa; Alanbay, Ibrahim; Keskin, Uğur; Karasahin, Emre; Yenen, Müfit Cemal

2016-01-01

A preliminary study was designed to evaluate whether a narrow-band imaging (NBI) endoscopic light source could detect chronic endometritis that was not identifiable with a white light hysteroscope. A total of 86 patients with endometrial pathology (71 abnormal uterine bleeding and 15 postmenopausal bleeding) were examined by NBI endoscopy and white light hysteroscopy between February 2010 and February 2011. The surgeon initially observed the uterine cavity using white light hysteroscopy and made a diagnostic impression, which was recorded. Subsequently, after pressing a button on the telescope, NBI was used to reevaluate the endometrial mucosa. The median age of the patients was 40 years (range: 30-60 years). Endometritis was diagnosed histologically. Six cases of abnormal uterine bleeding (6/71, 8.4%, 95% confidence interval [CI] 0.03-0.17) and one case of postmenopausal bleeding (1/15, 6%, 95%CI 0.01-0.29) were only diagnosed with chronic endometritis by NBI (7/86, 8.1%, 95%CI 0.04-0.15). Capillary patterns of the endometrium can be observed by NBI and this method can be used to assess chronic endometritis. © 2015 Japan Society of Obstetrics and Gynecology.

The learning curve for narrow-band imaging in the diagnosis of precancerous gastric lesions by using Web-based video.

PubMed

Dias-Silva, Diogo; Pimentel-Nunes, Pedro; Magalhães, Joana; Magalhães, Ricardo; Veloso, Nuno; Ferreira, Carlos; Figueiredo, Pedro; Moutinho, Pedro; Dinis-Ribeiro, Mário

2014-06-01

A simplified narrow-band imaging (NBI) endoscopy classification of gastric precancerous and cancerous lesions was derived and validated in a multicenter study. This classification comes with the need for dissemination through adequate training. To address the learning curve of this classification by endoscopists with differing expertise and to assess the feasibility of a YouTube-based learning program to disseminate it. Prospective study. Five centers. Six gastroenterologists (3 trainees, 3 fully trained endoscopists [FTs]). Twenty tests provided through a Web-based program containing 10 randomly ordered NBI videos of gastric mucosa were taken. Feedback was sent 7 days after every test submission. Measures of accuracy of the NBI classification throughout the time. From the first to the last 50 videos, a learning curve was observed with a 10% increase in global accuracy, for both trainees (from 64% to 74%) and FTs (from 56% to 65%). After 200 videos, sensitivity and specificity of 80% and higher for intestinal metaplasia were observed in half the participants, and a specificity for dysplasia greater than 95%, along with a relevant likelihood ratio for a positive result of 7 to 28 and likelihood ratio for a negative result of 0.21 to 0.82, were achieved by all of the participants. No constant learning curve was observed for the identification of Helicobacter pylori gastritis and sensitivity to dysplasia. The trainees had better results in all of the parameters, except specificity for dysplasia, compared with the FTs. Globally, participants agreed that the program's structure was adequate, except on the feedback, which should have consisted of a more detailed explanation of each answer. No formal sample size estimate. A Web-based learning program could be used to teach and disseminate classifications in the endoscopy field. In this study, an NBI classification for gastric mucosal features seems to be easily learned for the identification of gastric preneoplastic lesions. Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Real-Time Optical Biopsy of Colon Polyps With Narrow Band Imaging in Community Practice Does Not Yet Meet Key Thresholds for Clinical Decisions

PubMed Central

LADABAUM, URI; FIORITTO, ANN; MITANI, AYA; DESAI, MANISHA; KIM, JANE P.; REX, DOUGLAS K.; IMPERIALE, THOMAS; GUNARATNAM, NARESH

2017-01-01

BACKGROUND & AIMS Accurate optical analysis of colorectal polyps (optical biopsy) could prevent unnecessary polypectomies or allow a “resect and discard” strategy with surveillance intervals determined based on the results of the optical biopsy; this could be less expensive than histopathologic analysis of polyps. We prospectively evaluated real-time optical biopsy analysis of polyps with narrow band imaging (NBI) by community-based gastroenterologists. METHODS We first analyzed a computerized module to train gastroenterologists (N = 13) in optical biopsy skills using photographs of polyps. Then we evaluated a practice-based learning program for these gastroenterologists (n = 12) that included real-time optical analysis of polyps in vivo, comparison of optical biopsy predictions to histopathologic analysis, and ongoing feedback on performance. RESULTS Twelve of 13 subjects identified adenomas with >90% accuracy at the end of the computer study, and 3 of 12 subjects did so with accuracy ≥90% in the in vivo study. Learning curves showed considerable variation among batches of polyps. For diminutive rectosigmoid polyps assessed with high confidence at the end of the study, adenomas were identified with mean (95% confidence interval [CI]) accuracy, sensitivity, specificity, and negative predictive values of 81% (73%–89%), 85% (74%–96%), 78% (66%–92%), and 91% (86%–97%), respectively. The adjusted odds ratio for high confidence as a predictor of accuracy was 1.8 (95% CI, 1.3–2.5). The agreement between surveillance recommendations informed by high-confidence NBI analysis of diminutive polyps and results from histopathologic analysis of all polyps was 80% (95% CI, 77%–82%). CONCLUSIONS In an evaluation of real-time optical biopsy analysis of polyps with NBI, only 25% of gastroenterologists assessed polyps with ≥90% accuracy. The negative predictive value for identification of adenomas, but not the surveillance interval agreement, met the American Society for Gastrointestinal Endoscopy–recommended thresholds for optical biopsy. Better results in community practice must be achieved before NBI-based optical biopsy methods can be used routinely to evaluate polyps; ClinicalTrials.gov number, NCT01638091. PMID:23041328

Initial exploration of scenarios with Internal Transport Barrier in the first NBI-heated L-mode TCV plasmas

NASA Astrophysics Data System (ADS)

Piron, Chiara; Sauter, Olivier; Coda, Stefano; Merle, Antoine; Karpushov, Alexander; Pigatto, Leonardo; Bolzonella, Tommaso; Piovesan, Paolo; Vianello, Nicola; TCV Team; EUROfusion MST1 Team

2016-10-01

Fully non-inductive operation of high performance plasmas is one of the main objectives of contemporary Tokamak research. In this perspective, plasmas with Internal Transport Barriers (ITBs) are an attractive scenario, since they can attain a high fraction of bootstrap current. In this work we start exploring ITB scenarios on the Tokamak à Configuration Variable (TCV) heated by a newly available 1MW Neutral Beam Injector (NBI). Here we investigate for the first time in this device the impact of the additional NBI power on the performance and stability of L-mode plasmas with ITBs. Results of both experimental data analyses and ASTRA transport simulations are presented. The work examines also the Magneto Hydro-Dynamics (MHD) activity and stability of the explored plasmas. In particular, the role of plasma magnetic equilibrium parameters, such as plasma elongation and triangularity, on the sustainment of these NBI-heated ITB scenarios is discussed.

Development of a radio frequency ion source with multi-helicon plasma injectors for neutral beam injection system of Versatile Experiment Spherical Torus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choe, Kyumin; Jung, Bongki; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr

2014-02-15

Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 × 120 × 120 mm{sup 3}), four helicon plasma injectors with annular permanent magnetsmore » and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.« less

Development of a radio frequency ion source with multi-helicon plasma injectors for neutral beam injection system of Versatile Experiment Spherical Torus

NASA Astrophysics Data System (ADS)

Choe, Kyumin; Jung, Bongki; Chung, Kyoung-Jae; Hwang, Y. S.

2014-02-01

Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 × 120 × 120 mm3), four helicon plasma injectors with annular permanent magnets and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.

Development of a radio frequency ion source with multi-helicon plasma injectors for neutral beam injection system of Versatile Experiment Spherical Torus.

PubMed

Choe, Kyumin; Jung, Bongki; Chung, Kyoung-Jae; Hwang, Y S

2014-02-01

Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 × 120 × 120 mm(3)), four helicon plasma injectors with annular permanent magnets and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.

Commissioning and Plans for the NSTX-U Facility

NASA Astrophysics Data System (ADS)

Ono, Masayuki; NSTX-U Team

2016-10-01

The National Spherical Torus Experiment - Upgrade (NSTX-U) has started its first year of plasma operations after the successful completion of the CD-4 milestones. The unique operating regimes of NSTX-U can contribute to several important issues in the physics of burning plasmas to optimize the performance of ITER. The major mission of NSTX-U is also to develop the physics and technology basis for an ST-based Fusion Nuclear Science Facility (FNSF). The new center stack will provide toroidal field of 1 Tesla at a major radius of 0.93 m which should enable a plasma current of up to 2 mega-Amp for 5 sec. A much more tangential 2nd NBI system, with 2-3 times higher current drive efficiency compared to the 1st NBI system, is installed. NSTX-U is designed to attain the 100% non-inductive operation needed for a compact FNSF design. With higher fields and heating powers of 14 MW, the NSTX-U plasma collisionality will be reduced by a factor of 3-6 to help explore the trend in transport towards the low collisionality FNSF regime. If the favorable trends observed on NSTX holds at low collisionality, high fusion neutron fluences could be achievable in very compact ST devices.

Active spectroscopy upgrades and neutral beam injection on LTX- β

NASA Astrophysics Data System (ADS)

Elliott, Drew; Biewer, Theodore; Canik, John; Reinke, Matthew; Bell, Ronald; Boyle, Dennis; Guttenfelder, Walter; Kaita, Robert; Kozub, Thomas; Majeski, Richard; Merino, Enrique

2017-10-01

The LTX- β upgrade includes the addition of neutral beam injection (NBI) and increased active spectroscopy. Typical plasmas have been and are expected to remain inboard limited, at 14 cm with minor radii of 18-23 cm. The NBI, 35 Amps of 20 keV particles, will enable active diagnosis of ion velocity distribution profiles through charge exchange (CHERS). 18 CHERS views will cover more than a full minor radius, each sampling 2 cm of major radius. The system has both a set of beam directed ``active'' views and a symmetric set of views pointing away from the beam for stray light subtraction. Along with measuring ion temperatures and impurity transport, the CHERS diagnostic will measure the plasma rotation profiles. The recently described low recycling regime is predicted to allow for high rotational velocities due to the low neutral drag. The planned NBI has been predicted to give on axis velocities near 100 km/s. Flow shear is expected to increase confinement in this regime by suppressing trapped electron mode and other microturbulence enhanced transport. Upgrades to the Thomson scattering system, including an array of polychromators and a new camera, will assist in diagnosing the low density hot edge in this low recycling regime. Supported by US DOE contracts DE-AC02-09CH11466 and DE-AC05-00OR22725.

Diagnostic accuracy of pit pattern and vascular pattern analyses in colorectal lesions.

PubMed

Wada, Yoshiki; Kashida, Hiroshi; Kudo, Shin-ei; Misawa, Masashi; Ikehara, Nobunao; Hamatani, Shigeharu

2010-07-01

The aim of this prospective study is to compare the usefulness of magnifying narrow band imaging (NBI) and magnifying chromoendoscopy in the diagnosis of colorectal lesions. The subjects were 1185 patients who underwent a complete colonoscopic examination and endoscopic or surgical treatment, from January 2006 to February 2008. A total of 1473 lesions were evaluated (53 hyperplastic polyps, 1317 adenomas, 103 submucosally invasive cancers). The digital images with NBI or chromoendoscopy were recorded and diagnosed independently from each other by two endoscopists who were blinded to the final pathological diagnosis. We could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 88.9%, specificity of 98.5% and accuracy of 98.2% according to the vascular pattern. By recognizing an irregular or sparse pattern with NBI, massively invasive submucosal cancer could be diagnosed with the sensitivity and specificity of 94.9% and 76.0%. Using chromoendoscopy, we could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 86.8% and specificity of 99.2%. We were able to differentiate between massively invasive cancers and slightly invasive cancers using the pit patterns with sensitivity of 89.7% and specificity of 88.0%. The specificity was superior to that of NBI colonoscopy. Both NBI and chromoendoscopy can be useful for distinguishing between neoplastic and non-neoplastic lesions. In the diagnosis of submucosal cancer, pit pattern diagnosis was slightly superior to vascular pattern diagnosis. It is desirable to perform chromoendoscopy in addition to NBI for distinguishing between slightly and massively invasive submucosal cancer lesions and determining the treatment.

Ion collector design for an energy recovery test proposal with the negative ion source NIO1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Variale, V., E-mail: vincenzo.variale@ba.infn.it; Cavenago, M.; Agostinetti, P.

2016-02-15

Commercial viability of thermonuclear fusion power plants depends also on minimizing the recirculation power used to operate the reactor. The neutral beam injector (NBI) remains one of the most important method for plasma heating and control. For the future fusion power plant project DEMO, a NBI wall plug efficiency at least of 0.45 is required, while efficiency of present NBI project is about 0.25. The D{sup −} beam from a negative ion source is partially neutralized by a gas cell, which leaves more than 40% of energy in residual beams (D{sup −} and D{sup +}), so that an ion beammore » energy recovery system can significantly contribute to optimize efficiency. Recently, the test negative ion source NIO1 (60 keV, 9 beamlets with 15 mA H{sup −} each) has been designed and built at RFX (Padua) for negative ion production efficiency and the beam quality optimization. In this paper, a study proposal to use the NIO1 source also for a beam energy recovery test experiment is presented and a preliminary design of a negative ion beam collector with simulations of beam energy recovery is discussed.« less

Accurate and diverse recommendations via eliminating redundant correlations

NASA Astrophysics Data System (ADS)

Zhou, Tao; Su, Ri-Qi; Liu, Run-Ran; Jiang, Luo-Luo; Wang, Bing-Hong; Zhang, Yi-Cheng

2009-12-01

In this paper, based on a weighted projection of a bipartite user-object network, we introduce a personalized recommendation algorithm, called network-based inference (NBI), which has higher accuracy than the classical algorithm, namely collaborative filtering. In NBI, the correlation resulting from a specific attribute may be repeatedly counted in the cumulative recommendations from different objects. By considering the higher order correlations, we design an improved algorithm that can, to some extent, eliminate the redundant correlations. We test our algorithm on two benchmark data sets, MovieLens and Netflix. Compared with NBI, the algorithmic accuracy, measured by the ranking score, can be further improved by 23 per cent for MovieLens and 22 per cent for Netflix. The present algorithm can even outperform the Latent Dirichlet Allocation algorithm, which requires much longer computational time. Furthermore, most previous studies considered the algorithmic accuracy only; in this paper, we argue that the diversity and popularity, as two significant criteria of algorithmic performance, should also be taken into account. With more or less the same accuracy, an algorithm giving higher diversity and lower popularity is more favorable. Numerical results show that the present algorithm can outperform the standard one simultaneously in all five adopted metrics: lower ranking score and higher precision for accuracy, larger Hamming distance and lower intra-similarity for diversity, as well as smaller average degree for popularity.

Personalized recommendation via an improved NBI algorithm and user influence model in a Microblog network

NASA Astrophysics Data System (ADS)

Lian, Jie; Liu, Yun; Zhang, Zhen-jiang; Gui, Chang-ni

2013-10-01

Bipartite network based recommendations have attracted extensive attentions in recent years. Differing from traditional object-oriented recommendations, the recommendation in a Microblog network has two crucial differences. One is high authority users or one’s special friends usually play a very active role in tweet-oriented recommendation. The other is that the object in a Microblog network corresponds to a set of tweets on same topic instead of an actual and single entity, e.g. goods or movies in traditional networks. Thus repeat recommendations of the tweets in one’s collected topics are indispensable. Therefore, this paper improves network based inference (NBI) algorithm by original link matrix and link weight on resource allocation processes. This paper finally proposes the Microblog recommendation model based on the factors of improved network based inference and user influence model. Adjusting the weights of these two factors could generate the best recommendation results in algorithm accuracy and recommendation personalization.

Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

NASA Astrophysics Data System (ADS)

Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

2018-04-01

Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

A novel approach emphasising intra-operative superficial margin enhancement of head-neck tumours with narrow-band imaging in transoral robotic surgery.

PubMed

Vicini, C; Montevecchi, F; D'Agostino, G; DE Vito, A; Meccariello, G

2015-06-01

The primary goal of surgical oncology is to obtain a tumour resection with disease-free margins. Transoral robotic surgery (TORS) for surgical treatment of head-neck cancer is commensurate with standard treatments. However, the likelihood of positive margins after TORS is up to 20.2% in a recent US survey. The aim of this study is to evaluate the efficacy and the feasibility of narrow-band imaging (NBI) during TORS in order to improve the ability to achieve disease-free margins during tumour excision. The present study was conducted at the ENT, Head- Neck Surgery and Oral Surgery Unit, Department of Special Surgery, Morgagni Pierantoni Hospital, Azienda USL Romagna. From March 2008 to January 2015, 333 TORS were carried out for malignant and benign diseases. For the present study, we retrospectively evaluated 58 biopsy-proven squamous cell carcinoma patients who underwent TORS procedures. Patients were divided into 2 groups: (1) 32 who underwent TORS and intra-operative NBI evaluation (NBI-TORS); (2) 21 who underwent TORS with standard intra-operative white-light imaging (WLITORS). Frozen section analysis of margins on surgical specimens showed a higher rate of negative superficial lateral margins in the NBI-TORS group compared with the WLI-TORS group (87.9% vs. 57.9%, respectively, p = 0.02). The sensitivity and specificity of intra-operative use of NBI, respectively, were 72.5% and 66.7% with a negative predictive value of 87.9%. Tumour margin enhancement provided by NBI associated with magnification and 3-dimensional view of the surgical field might increase the capability to achieve an oncologically-safe resection in challenging anatomical areas where minimal curative resection is strongly recommended for function preservation.

Clinical evaluation of endoscopic trimodal imaging for the detection and differentiation of colonic polyps.

PubMed

van den Broek, Frank J C; Fockens, Paul; Van Eeden, Susanne; Kara, Mohammed A; Hardwick, James C H; Reitsma, Johannes B; Dekker, Evelien

2009-03-01

Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for adenoma detection and to assess the diagnostic accuracy of NBI for differentiation of polyps. This was a randomized trial of tandem colonoscopies. The study was performed at the Academic Medical Center in Amsterdam. One hundred patients underwent colonoscopy with ETMI. Each colonic segment was examined twice for polyps, once with HRE and once with AFI, in random order per patient. All detected polyps were assessed with NBI for pit pattern and with AFI for color, and subsequently removed. Histopathology served as the gold standard for diagnosis. The main outcome measures of this study were adenoma miss-rates of AFI and HRE, and diagnostic accuracy of NBI and AFI for differentiating adenomas from nonneoplastic polyps. Among 50 patients examined with AFI first, 32 adenomas were detected initially. Subsequent inspection with HRE identified 8 additional adenomas. Among 50 patients examined with HRE first, 35 adenomas were detected initially. Successive AFI yielded 14 additional adenomas. The adenoma miss-rates of AFI and HRE therefore were 20% and 29%, respectively (P = .351). The sensitivity, specificity, and overall accuracy of NBI for differentiation were 90%, 70%, and 79%, respectively; corresponding figures for AFI were 99%, 35%, and 63%, respectively. The overall adenoma miss-rate was 25%; AFI did not significantly reduce the adenoma miss-rate compared with HRE. Both NBI and AFI had a disappointing diagnostic accuracy for polyp differentiation, although AFI had a high sensitivity.

PubMed Central

VICINI, C.; MONTEVECCHI, F.; D'AGOSTINO, G.; DE VITO, A.

2015-01-01

SUMMARY The primary goal of surgical oncology is to obtain a tumour resection with disease-free margins. Transoral robotic surgery (TORS) for surgical treatment of head-neck cancer is commensurate with standard treatments. However, the likelihood of positive margins after TORS is up to 20.2% in a recent US survey. The aim of this study is to evaluate the efficacy and the feasibility of narrow-band imaging (NBI) during TORS in order to improve the ability to achieve disease-free margins during tumour excision. The present study was conducted at the ENT, Head- Neck Surgery and Oral Surgery Unit, Department of Special Surgery, Morgagni Pierantoni Hospital, Azienda USL Romagna. From March 2008 to January 2015, 333 TORS were carried out for malignant and benign diseases. For the present study, we retrospectively evaluated 58 biopsy-proven squamous cell carcinoma patients who underwent TORS procedures. Patients were divided into 2 groups: (1) 32 who underwent TORS and intra-operative NBI evaluation (NBI-TORS); (2) 21 who underwent TORS with standard intra-operative white-light imaging (WLITORS). Frozen section analysis of margins on surgical specimens showed a higher rate of negative superficial lateral margins in the NBI-TORS group compared with the WLI-TORS group (87.9% vs. 57.9%, respectively, p = 0.02). The sensitivity and specificity of intra-operative use of NBI, respectively, were 72.5% and 66.7% with a negative predictive value of 87.9%. Tumour margin enhancement provided by NBI associated with magnification and 3-dimensional view of the surgical field might increase the capability to achieve an oncologically-safe resection in challenging anatomical areas where minimal curative resection is strongly recommended for function preservation. PMID:26246659

Change in Pain and Quality of Life Among Women Enrolled in a Trial Examining the Use of Narrow Band Imaging During Laparoscopic Surgery for Suspected Endometriosis.

PubMed

Gallicchio, Lisa; Helzlsouer, Kathy J; Audlin, Kevin M; Miller, Charles; MacDonald, Ryan; Johnston, Mary; Barrueto, Fermin F

2015-01-01

To examine whether the addition of narrow band imaging (NBI) to traditional white light imaging during laparoscopic surgery impacts pain and quality of life (QOL) at 3 and 6 months after surgery among women with suspected endometriosis and/or infertility. A randomized controlled trial (Canadian Task Force classification level I). The trial was conducted in 2 medical centers. From October 2011 to November 2013, 167 patients undergoing laparoscopic examination for suspected endometriosis and/or infertility were recruited. The analytic study sample includes 148 patients with pain and QOL outcome data. Patients were randomized in a 3:1 ratio to receive white light imaging followed by NBI (WL/NBI) or white light imaging only (WL/WL). Questionnaires were administered at baseline and at 3- and 6-month follow-up time points. Average and most severe pain at each time point were assessed using a 10-cm visual analog scale. QOL was measured using the Endometriosis Health Profile-30. Baseline characteristics were similar for the study groups. The WL/NBI and WL/WL groups had similar reductions in pain at 3 and 6 months. In addition, QOL improved similarly for both the WL/NBI and WL/WL groups at 3 and 6 months. Laparoscopic surgery for suspected endometriosis is associated with a reduction in pain and an improvement in QOL. The differences in pain reduction and QOL improvement, which are noted at 3 months and remain stable at 6 months after surgery, are similar for those undergoing surgery with WL/NBI compared with those undergoing surgery under traditional white light conditions. Copyright © 2015 AAGL. Published by Elsevier Inc. All rights reserved.

Long-pulse power-supply system for EAST neutral-beam injectors

NASA Astrophysics Data System (ADS)

Liu, Zhimin; Jiang, Caichao; Pan, Junjun; Liu, Sheng; Xu, Yongjian; Chen, Shiyong; Hu, Chundong; NBI Team

2017-05-01

The long-pulse power-supply system equipped for the 4 MW beam-power ion source is comprised of three units at ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences): one for the neutral-beam test stand and two for the EAST neutral-beam injectors (NBI-1 and NBI-2, respectively). Each power supply system consists of two low voltage and high current DC power supplies for plasma generation of the ion source, and two high voltage and high current DC power supplies for the accelerator grid system. The operation range of the NB power supply is about 80 percent of the design value, which is the safe and stable operation range. At the neutral-beam test stand, a hydrogen ion beam with a beam pulse of 150 s, beam power of 1.5 MW and beam energy of 50 keV was achieved during the long-pulse testing experiments. The result shows that the power-supply system meets the requirements of the EAST-NBIs fully and lays a basis for achieving plasma heating.

Single Dose and Repeat Once-Daily Dose Safety, Tolerability and Pharmacokinetics of Valbenazine in Healthy Male Subjects.

PubMed

Luo, Rosa; Bozigian, Haig; Jimenez, Roland; Loewen, Gordon; O'Brien, Christopher F

2017-08-01

Valbenazine (VBZ) is a vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia. The safety, tolerability and pharmacokinetics of VBZ following single and repeat once-daily (QD) dosing were evaluated in 2 randomized, single-center, double-blind studies in healthy male subjects. In the first study, 2 cohorts of 8 subjects were administered single doses (SD) of placebo (PBO; N = 2/period) or VBZ (N = 6/period; 1, 2, 5, or 12.5 mg for Cohort 1 and 12.5, 25, 50, or 75 mg for Cohort 2) using a sequential escalation scheme. The second study consisted of 2 phases. In the initial phase, subjects were administered SD PBO (N = 2/period) or VBZ (N = 6/period; 75, 100, 125 or 150 mg) with sequential escalation. In the second phase, subjects received PBO, or 50 or 100 mg VBZ (N = 4:8:8) QD for 8 days (Cohort 1) or PBO or 50 mg VBZ (N = 6:6) QD for 8 days (Cohort 2). For both studies, plasma concentrations of VBZ and its active metabolite, NBI-98782, were determined. Safety was assessed throughout the studies. PK parameters were determined using noncompartmental methods. In both studies, VBZ was rapidly absorbed with peak concentrations typically observed within 1.5 hours. Peak NBI-98782 concentrations were typically observed at 4.0 to 9.0 hours. Terminal elimination half-life for both VBZ and NBI-98782 was ~20 hours. Across the 1 to 150 mg SD range evaluated across the studies, VBZ and NBI-98782 C max and AUC increased dose-proportionally from 50 to 150 mg and more than dose-proportionally from 1 to 50 mg. QD VBZ and NBI-98782 C max and AUC parameters were also dose-proportional between the 50 and 100 mg doses. Steady-state for both analytes appeared to be achieved by Day 8. The accumulation index was ~1.5 for VBZ and ~2.5 for NBI-98782. Peak to trough fluctuation was approximately 250% for VBZ and 70% for NBI-98782. Across both studies, NBI-98782 exposure was approximately 20%-30% that of VBZ based on molar ratios. In the first study, the maximum-tolerated dose was not achieved; headache (2 events) was the only treatment-emergent adverse event (TEAE) reported by more than one subject. In the second study, fatigue (4 events) was the only TEAE reported by more than one subject following SD VBZ. Following QD VBZ, the TEAEs of fatigue, insomnia, disturbance in attention, and nervousness were dose-dependent; the latter three TEAEs were considered dose-limiting. Subject withdrawals due to TEAEs were 1 each for PBO and 50 mg VBZ QD, and 3 for 100 mg VBZ QD. Clinically relevant effects on laboratory parameters, vital signs or ECGs were limited to increased CPK (SD: 1 each for 5 mg VBZ and PBO), ALT (QD: 1 each for 50 and 100 mg VBZ and PBO), and triglycerides (QD: 1 each for 50 mg VBZ and PBO). VBZ has an acceptable safety profile and predictable pharmacokinetics that result in stable concentrations of active compounds with low peak-to-trough fluctuation following once-daily dosing.

Single Dose and Repeat Once-Daily Dose Safety, Tolerability and Pharmacokinetics of Valbenazine in Healthy Male Subjects

PubMed Central

Luo, Rosa; Bozigian, Haig; Jimenez, Roland; Loewen, Gordon; O’Brien, Christopher F.

2017-01-01

Valbenazine (VBZ) is a vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia. The safety, tolerability and pharmacokinetics of VBZ following single and repeat once-daily (QD) dosing were evaluated in 2 randomized, single-center, double-blind studies in healthy male subjects. In the first study, 2 cohorts of 8 subjects were administered single doses (SD) of placebo (PBO; N = 2/period) or VBZ (N = 6/period; 1, 2, 5, or 12.5 mg for Cohort 1 and 12.5, 25, 50, or 75 mg for Cohort 2) using a sequential escalation scheme. The second study consisted of 2 phases. In the initial phase, subjects were administered SD PBO (N = 2/period) or VBZ (N = 6/period; 75, 100, 125 or 150 mg) with sequential escalation. In the second phase, subjects received PBO, or 50 or 100 mg VBZ (N = 4:8:8) QD for 8 days (Cohort 1) or PBO or 50 mg VBZ (N = 6:6) QD for 8 days (Cohort 2). For both studies, plasma concentrations of VBZ and its active metabolite, NBI-98782, were determined. Safety was assessed throughout the studies. PK parameters were determined using noncompartmental methods. In both studies, VBZ was rapidly absorbed with peak concentrations typically observed within 1.5 hours. Peak NBI-98782 concentrations were typically observed at 4.0 to 9.0 hours. Terminal elimination half-life for both VBZ and NBI-98782 was ~20 hours. Across the 1 to 150 mg SD range evaluated across the studies, VBZ and NBI-98782 Cmax and AUC increased dose-proportionally from 50 to 150 mg and more than dose-proportionally from 1 to 50 mg. QD VBZ and NBI-98782 Cmax and AUC parameters were also dose-proportional between the 50 and 100 mg doses. Steady-state for both analytes appeared to be achieved by Day 8. The accumulation index was ~1.5 for VBZ and ~2.5 for NBI-98782. Peak to trough fluctuation was approximately 250% for VBZ and 70% for NBI-98782. Across both studies, NBI-98782 exposure was approximately 20%–30% that of VBZ based on molar ratios. In the first study, the maximum-tolerated dose was not achieved; headache (2 events) was the only treatment-emergent adverse event (TEAE) reported by more than one subject. In the second study, fatigue (4 events) was the only TEAE reported by more than one subject following SD VBZ. Following QD VBZ, the TEAEs of fatigue, insomnia, disturbance in attention, and nervousness were dose-dependent; the latter three TEAEs were considered dose-limiting. Subject withdrawals due to TEAEs were 1 each for PBO and 50 mg VBZ QD, and 3 for 100 mg VBZ QD. Clinically relevant effects on laboratory parameters, vital signs or ECGs were limited to increased CPK (SD: 1 each for 5 mg VBZ and PBO), ALT (QD: 1 each for 50 and 100 mg VBZ and PBO), and triglycerides (QD: 1 each for 50 mg VBZ and PBO). VBZ has an acceptable safety profile and predictable pharmacokinetics that result in stable concentrations of active compounds with low peak-to-trough fluctuation following once-daily dosing. PMID:28839339

Identification of an hexapeptide that binds to a surface pocket in cyclin A and inhibits the catalytic activity of the complex cyclin-dependent kinase 2-cyclin A.

PubMed

Canela, Núria; Orzáez, Mar; Fucho, Raquel; Mateo, Francesca; Gutierrez, Ricardo; Pineda-Lucena, Antonio; Bachs, Oriol; Pérez-Payá, Enrique

2006-11-24

The protein-protein complexes formed between different cyclins and cyclin-dependent kinases (CDKs) are central to cell cycle regulation. These complexes represent interesting points of chemical intervention for the development of antineoplastic molecules. Here we describe the identification of an all d-amino acid hexapeptide, termed NBI1, that inhibits the kinase activity of the cyclin-dependent kinase 2 (cdk2)-cyclin A complex through selective binding to cyclin A. The mechanism of inhibition is non-competitive for ATP and non-competitive for protein substrates. In contrast to the existing CDKs peptide inhibitors, the hexapeptide NBI1 interferes with the formation of the cdk2-cyclin A complex. Furthermore, a cell-permeable derivative of NBI1 induces apoptosis and inhibits proliferation of tumor cell lines. Thus, the NBI1-binding site on cyclin A may represent a new target site for the selective inhibition of activity cdk2-cyclin A complex.

Analysis of past NBI ratings to determine future bridge preservation needs.

DOT National Transportation Integrated Search

2004-01-01

Bridge Management System (BMS) needs an analytical tool that can predict bridge element deterioration and answer questions related to bridge preservation. PONTIS, a comprehensive BMS software, was developed to serve this purpose. However, the intensi...

NBI - plasma vaporization hybrid approach in bladder cancer endoscopic management.

PubMed

Stănescu, F; Geavlete, B; Georgescu, D; Jecu, M; Moldoveanu, C; Adou, L; Bulai, C; Ene, C; Geavlete, P

2014-06-15

A prospective study was performed aiming to evaluate the surgical efficacy, perioperative safety profile, diagnostic accuracy and medium term results of a multi-modal approach consisting in narrow band imaging (NBI) cystoscopy and bipolar plasma vaporization (BPV) when compared to the standard protocol represented by white light cystoscopy (WLC) and transurethral resection of bladder tumors (TURBT). A total of 260 patients with apparently at least one bladder tumor over 3 cm were included in the trial. In the first group, 130 patients underwent conventional and NBI cystoscopy followed by BPV, while in a similar number of cases of the second arm, classical WLC and TURBT were applied. In all non-muscle invasive bladder tumors' (NMIBT) pathologically confirmed cases, standard monopolar Re-TUR was performed at 4-6 weeks after the initial intervention, followed by one year' BCG immunotherapy. The follow-up protocol included abdominal ultrasound, urinary cytology and WLC, performed every 3 months for a period of 2 years. The obturator nerve stimulation, bladder wall perforation, mean hemoglobin level drop, postoperative bleeding, catheterization period and hospital stay were significantly reduced for the plasma vaporization technique by comparison to conventional resection. Concerning tumoral detection, the present data confirmed the NBI superiority when compared to standard WLC regardless of tumor stage (95.3% vs. 65.1% for CIS, 93.3% vs. 82.2% for pTa, 97.4% vs. 94% for pT1, 95% vs. 84.2% overall). During standard Re-TUR the overall (6.3% versus 17.4%) and primary site (3.6% versus 12.8%) residual tumors' rates were significantly lower for the NBI-BPV group. The 1 (7.2% versus 18.3%) and 2 (11.5% versus 25.8%) years' recurrence rates were substantially lower for the combined approach. NBI cystoscopy significantly improved diagnostic accuracy, while bipolar technology showed a higher surgical efficiency, lower morbidity and faster postoperative recovery. The combined technique offered a reduced rate of residual tumors at Re-TUR, both globally as well as for orthotopic tumors. Substantially lower recurrence rates were found at 1 and 2 years among the NBI-BPV cases.

A series of coordination polymers constructed from R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands: Syntheses, structures and fluorescence properties

NASA Astrophysics Data System (ADS)

Zhou, Yong-Hong; Zhou, Xu-Wan; Zhou, Su-Rong; Tian, Yu-Peng; Wu, Jie-Ying

2017-01-01

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn2Na(sip)2(bpp)3(Hbpp)(H2O)2]·8H2O (1), [Cd3(sip)2(nbi)6(H2O)2]·7H2O (2), [Zn(sip)(nbi)2(H2O)]·Hnbi·3H2O (3), [Cd(hip)(nbi)2(H2O)]·nbi·5H2O (4), [Cd2(nip)2(nbi)2(H2O)2]·DMF (5), and [Cu(nip)(nbi)(H2O)2]·H2O (6) (H3sip=5-sulfoisophthalic acid, H2hip=5-hydroxylisophthalic acid, H2nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip3- anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3-5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip2- ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied.

Study of neutron generation in the compact tokamak TUMAN-3M in support of a tokamak-based fusion neutron source

NASA Astrophysics Data System (ADS)

Kornev, V. A.; Askinazi, L. G.; Belokurov, A. A.; Chernyshev, F. V.; Lebedev, S. V.; Melnik, A. D.; Shabelsky, A. A.; Tukachinsky, A. S.; Zhubr, N. A.

2017-12-01

The paper presents DD neutron flux measurements in neutron beam injection (NBI) experiments aimed at the optimization of target plasma and heating beam parameters to achieve maximum neutron flux in the TUMAN-3M compact tokamak. Two ion sources of different design were used, which allowed the separation of the beam’s energy and power influence on the neutron rate. Using the database of experiments performed with the two ion sources, an empirical scaling was derived describing the neutron rate dependence on the target plasma and heating beam parameters. Numerical modeling of the neutron rate in the NBI experiments performed using the ASTRA transport code showed good agreement with the scaling.

Narrow-band imaging can increase the visibility of fibrin caps after bleeding of esophageal varices: a case with extensive esophageal candidiasis.

PubMed

Furuichi, Yoshihiro; Kasai, Yoshitaka; Takeuchi, Hirohito; Yoshimasu, Yuu; Kawai, Takashi; Sugimoto, Katsutoshi; Kobayashi, Yoshiyuki; Nakamura, Ikuo; Itoi, Takao

2017-08-01

A 58-year-old man with hepatitis B cirrhosis noticed black stools and underwent an endoscopy at a community hospital. The presence of esophageal varices (EVs) was confirmed, but the bleeding point was not found. He was referred to our institution and underwent a second endoscopy. Extensive white patches of esophageal candidiasis were visible on endoscopy by white-light imaging (WLI), but it was difficult to find the fibrin cap of the EVs. This was easier under narrow-band imaging (NBI), however, as the color turned red from absorption by hemoglobin adhered to it. We retrospectively measured the color differences (CD) between the fibrin cap and the surrounding mucosa 10 times using the CIE (L*a*b*) color space method. The median value of CD increased after NBI (13.9 → 43.0, p < 0.001), with increased visibility. However, the median CD between the white patch and surrounding mucosa decreased after NBI (44.8 → 30.3, p < 0.001). The fibrin cap was paler than the white patch of candidiasis, but the increased visibility of the fibrin cap by NBI enabled it to be found more easily. This is the first report of a case in which NBI was helpful in locating a fibrin cap of EVs.

Toroidal rotation and ion heating during neutral beam injection in PBX-M

NASA Astrophysics Data System (ADS)

Asakura, N.; Fonck, R. J.; Jaehnig, K. P.; Kaye, S. M.; LeBlanc, B.; Okabayashi, M.

1993-08-01

Determination of the profiles of the ion temperature and the plasma toroidal rotation has been accomplished by charge exchange recombination spectroscopy in PBX-M. The angular momentum and the thermal ion energy transport have been studied mainly during the H mode phase of a high βp discharge (Ip approx 330 kA, 3.5 × 1019 <= ne <= 6.5 × 1019 m-3) having different heating beam configurations (combination of two perpendicular and two tangential neutral beam injections, abbreviated as 2 perp. NBI and 2 parall. NBI). The toroidal rotation velocity Vphi rises substantially in the region of r/a >= 0.5 after the L-H transition, and the Vphi profile (peakedness) is more highly dependent on the beam configuration than the Ti profile. The angular momentum confinement time varies from 147 ms (rigid rotation for 2 perp. NBI) to 39 ms (viscous rotation for 2 parall. NBI). In contrast, the thermal energy confinement time is 44-48 ms and is almost independent of the configuration. The transport analysis shows that the radial angular momentum diffusion is caused mainly by the viscous losses and that the angular momentum diffusivity χphi is reduced substantially in the outer minor radius region during the 2 perp. NBI H mode. The neoclassical friction effect between the bulk ions and the impurities may influence the χphi profiles locally, where the ion temperature gradient is steep

Destabilization of counter-propagating TAEs by off-axis, co-current Neutral Beam Injection

NASA Astrophysics Data System (ADS)

Podesta', M.; Fredrickson, E.; Gorelenkova, M.

2017-10-01

Neutral Beam injection (NBI) is a common tool to heat the plasma and drive current non-inductively in fusion devices. Energetic particles (EP) resulting from NBI can drive instabilities that are detrimental for the performance and the predictability of plasma discharges. A broad NBI deposition profile, e.g. by off-axis injection aiming near the plasma mid-radius, is often assumed to limit those undesired effects by reducing the radial gradient of the EP density, thus reducing the ``universal'' drive for instabilities. However, this work presents new evidence that off-axis NBI can also lead to undesired effects such as the destabilization of Alfvénic instabilities, as observed in NSTX-U plasmas. Experimental observations indicate that counter propagating toroidal AEs are destabilized as the radial EP density profile becomes hollow as a result of off-axis NBI. Time-dependent analysis with the TRANSP code, augmented by a reduced fast ion transport model (known as kick model), indicates that instabilities are driven by a combination of radial and energy gradients in the EP distribution. Understanding the mechanisms for wave-particle interaction, revealed by the phase space resolved analysis, is the basis to identify strategies to mitigate or suppress the observed instabilities. Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, Philip Michael; Ahn, Joonwook; Bell, R. E.

High-harmonic fast wave (HHFW) heating and current drive is being developed in NSTX to provide bulk electron heating and q(0) control during non-inductively sustained Hmode plasmas fuelled by deuterium neutral-beam injection (NBI). In addition, it is used to assist the plasma current ramp-up. A major modification to increase the RF power limit was made in 2009; the original end-grounded, single end-powered current straps of the 12- element array were replaced with center-grounded, double end-powered straps. Greater than 3 MW have been coupled into NBI-driven, ELMy H-mode plasmas with this upgraded antenna. Improved core HHFW heating, particularly at longer wavelengths andmore » during low-density start-up and plasma current ramp-up, has been obtained by lowering the edge density with lithium wall conditioning, thereby moving the critical density for fast-wave propagation away from the vessel wall [1]. Significant core electron heating of NBI-fuelled H-modes has been observed for the first time over a range of launched wavelengths and H-modes can be accessed by HHFW alone. Visible and IR camera images of the antenna and divertor indicate that fast wave interactions can deposit considerable RF energy on the outboard divertor plate, especially at longer wavelengths that begin to propagate closer to the vessel walls. Edge power loss can also arise from HHFWgenerated parametric decay instabilities; edge ion heating is observed that is wavelength dependent. During plasmas where HHFW is combined with NBI, there is a significant enhancement in neutron rate, and fast-ion D-alpha (FIDA) emission measurements clearly show broadening of the fast-ion profile in the plasma core. Large edge localized modes (ELMs) have been observed immediately following the termination of RF power, whether the power turn off is programmed or due to antenna arcing. Causality has not been established but new experiments are planned and will be reported. Fast digitization of the reflected power signal indicates a much faster rise time for arcs than for ELMs. Based on this observation, an ELM/arc discrimination system is being implemented to maintain RF power during ELMs even when the reflection coefficient becomes large. This work is supported by US DOE contracts DE-AC-05-00OR22725 and DE-AC02- 09CH11466. References [1] C. K. Phillips, et al, Nuclear Fusion 10, 075015 (2009)« less

Development progresses of radio frequency ion source for neutral beam injector in fusion devices.

PubMed

Chang, D H; Jeong, S H; Kim, T S; Park, M; Lee, K W; In, S R

2014-02-01

A large-area RF (radio frequency)-driven ion source is being developed in Germany for the heating and current drive of an ITER device. Negative hydrogen ion sources are the major components of neutral beam injection systems in future large-scale fusion experiments such as ITER and DEMO. RF ion sources for the production of positive hydrogen (deuterium) ions have been successfully developed for the neutral beam heating systems at IPP (Max-Planck-Institute for Plasma Physics) in Germany. The first long-pulse ion source has been developed successfully with a magnetic bucket plasma generator including a filament heating structure for the first NBI system of the KSTAR tokamak. There is a development plan for an RF ion source at KAERI to extract the positive ions, which can be applied for the KSTAR NBI system and to extract the negative ions for future fusion devices such as the Fusion Neutron Source and Korea-DEMO. The characteristics of RF-driven plasmas and the uniformity of the plasma parameters in the test-RF ion source were investigated initially using an electrostatic probe.

Virtual chromoendoscopy for the real-time assessment of colorectal polyps in vivo: a systematic review and economic evaluation.

PubMed

Picot, Joanna; Rose, Micah; Cooper, Keith; Pickett, Karen; Lord, Joanne; Harris, Petra; Whyte, Sophie; Böhning, Dankmar; Shepherd, Jonathan

2017-12-01

Current clinical practice is to remove a colorectal polyp detected during colonoscopy and determine whether it is an adenoma or hyperplastic by histopathology. Identifying adenomas is important because they may eventually become cancerous if untreated, whereas hyperplastic polyps do not usually develop into cancer, and a surveillance interval is set based on the number and size of adenomas found. Virtual chromoendoscopy (VCE) (an electronic endoscopic imaging technique) could be used by the endoscopist under strictly controlled conditions for real-time optical diagnosis of diminutive (≤ 5 mm) colorectal polyps to replace histopathological diagnosis. To assess the clinical effectiveness and cost-effectiveness of the VCE technologies narrow-band imaging (NBI), flexible spectral imaging colour enhancement (FICE) and i-scan for the characterisation and management of diminutive (≤ 5 mm) colorectal polyps using high-definition (HD) systems without magnification. Systematic review and economic analysis. People undergoing colonoscopy for screening or surveillance or to investigate symptoms suggestive of colorectal cancer. NBI, FICE and i-scan. Diagnostic accuracy, recommended surveillance intervals, health-related quality of life (HRQoL), adverse effects, incidence of colorectal cancer, mortality and cost-effectiveness of VCE compared with histopathology. Electronic bibliographic databases including MEDLINE, EMBASE, The Cochrane Library and Database of Abstracts of Reviews of Effects were searched for published English-language studies from inception to June 2016. Bibliographies of related papers, systematic reviews and company information were screened and experts were contacted to identify additional evidence. Systematic reviews of test accuracy and economic evaluations were undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Meta-analyses were conducted, where possible, to inform the independent economic model. A cost-utility decision-analytic model was developed to estimate the cost-effectiveness of VCE compared with histopathology. The model used a decision tree for patients undergoing endoscopy, combined with estimates of long-term outcomes (e.g. incidence of colorectal cancer and subsequent morbidity and mortality) derived from University of Sheffield School of Health and Related Research's bowel cancer screening model. The model took a NHS perspective, with costs and benefits discounted at 3.5% over a lifetime horizon. There were limitations in the data on the distribution of adenomas across risk categories and recurrence rates post polypectomy. Thirty test accuracy studies were included: 24 for NBI, five for i-scan and three for FICE (two studies assessed two interventions). Polyp assessments made with high confidence were associated with higher sensitivity and endoscopists experienced in VCE achieved better results than those without experience. Two economic evaluations were included. NBI, i-scan and FICE are cost-saving strategies compared with histopathology and the number of quality-adjusted life-years gained was similar for histopathology and VCE. The correct surveillance interval would be given to 95% of patients with NBI, 94% of patients with FICE and 97% of patients with i-scan. Limited evidence was available for i-scan and FICE and there was heterogeneity among the NBI studies. There is a lack of data on longer-term health outcomes of patients undergoing VCE for assessment of diminutive colorectal polyps. VCE technologies, using HD systems without magnification, could potentially be used for the real-time assessment of diminutive colorectal polyps, if endoscopists have adequate experience and training. Future research priorities include head-to-head randomised controlled trials of all three VCE technologies; more research on the diagnostic accuracy of FICE and i-scan (when used without magnification); further studies evaluating the impact of endoscopist experience and training on outcomes; studies measuring adverse effects, HRQoL and anxiety; and longitudinal data on colorectal cancer incidence, HRQoL and mortality. This study is registered as PROSPERO CRD42016037767. The National Institute for Health Research Health Technology Assessment programme.

High-resolution endoscopy plus chromoendoscopy or narrow-band imaging in Barrett's esophagus: a prospective randomized crossover study.

PubMed

Kara, M A; Peters, F P; Rosmolen, W D; Krishnadath, K K; ten Kate, F J; Fockens, P; Bergman, J J G H

2005-10-01

High-resolution endoscopy (HRE) may improve the detection of early neoplasia in Barrett's esophagus. Indigo carmine chromoendoscopy (ICC) and narrow-band imaging (NBI) may be useful techniques to complement HRE. The aim of this study was to compare HRE-ICC with HRE-NBI for the detection of high-grade dysplasia or early cancer (HGD/EC) in patients with Barrett's esophagus. Twenty-eight patients with Barrett's esophagus underwent HRE-ICC and HRE-NBI (separated by 6 - 8 weeks) in a randomized sequence. The two procedures were performed by two different endoscopists, who were blinded to the findings of the other examination. Targeted biopsies were taken from all detected lesions, followed by four-quadrant biopsies at 2-cm intervals. Biopsy evaluation was supervised by a single expert pathologist, who was blinded to the imaging technique used. Fourteen patients were diagnosed with HGD/EC. The sensitivity for HGD/EC was 93 % and 86 % for HRE-ICC and HRE-NBI, respectively. Targeted biopsies had a sensitivity of 79 % with HRE alone. HGD was diagnosed from random biopsies alone in only one patient. ICC and NBI detected a limited number of additional lesions occult to HRE, but these lesions did not alter the sensitivity for identifying patients with HGD/EC. In most patients with high-grade dysplasia or early cancer in Barrett's esophagus, subtle lesions can be identified with high-resolution endoscopy. Indigo carmine chromoendoscopy and narrow-band imaging are comparable as adjuncts to high-resolution endoscopy.

The Cadarache negative ion experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massmann, P.; Bottereau, J.M.; Belchenko, Y.

1995-12-31

Up to energies of 140 keV neutral beam injection (NBI) based on positive ions has proven to be a reliable and flexible plasma heating method and has provided major contributions to most of the important experiments on virtually all large tokamaks around the world. As a candidate for additional heating and current drive on next step fusion machines (ITER ao) it is hoped that NBI can be equally successful. The ITER NBI parameters of 1 MeV, 50 MW D{degree} demand primary D{sup {minus}} beams with current densities of at least 15 mA/cm{sup 2}. Although considerable progress has been made inmore » the area of negative ion production and acceleration the high demands still require substantial and urgent development. Regarding negative ion production Cs seeded plasma sources lead the way. Adding a small amount of Cs to the discharge (Cs seeding) not only increases the negative ion yield by a factor 3--5 but also has the advantage that the discharge can be run at lower pressures. This is beneficial for the reduction of stripping losses in the accelerator. Multi-ampere negative ion production in a large plasma source is studied in the MANTIS experiment. Acceleration and neutralization at ITER relevant parameters is the objective of the 1 MV SINGAP experiment.« less

Validation of Kinetic-Turbulent-Neoclassical Theory for Edge Intrinsic Rotation in DIII-D Plasmas

NASA Astrophysics Data System (ADS)

Ashourvan, Arash

2017-10-01

Recent experiments on DIII-D with low-torque neutral beam injection (NBI) have provided a validation of a new model of momentum generation in a wide range of conditions spanning L- and H-mode with direct ion and electron heating. A challenge in predicting the bulk rotation profile for ITER has been to capture the physics of momentum transport near the separatrix and steep gradient region. A recent theory has presented a model for edge momentum transport which predicts the value and direction of the main-ion intrinsic velocity at the pedestal-top, generated by the passing orbits in the inhomogeneous turbulent field. In this study, this model-predicted velocity is tested on DIII-D for a database of 44 low-torque NBI discharges comprised of bothL- and H-mode plasmas. For moderate NBI powers (PNBI<4 MW), model prediction agrees well with the experiments for both L- and H-mode. At higher NBI power the experimental rotation is observed to saturate and even degrade compared to theory. TRANSP-NUBEAM simulations performed for the database show that for discharges with nominally balanced - but high powered - NBI, the net injected torque through the edge can exceed 1 N.m in the counter-current direction. The theory model has been extended to compute the rotation degradation from this counter-current NBI torque by solving a reduced momentum evolution equation for the edge and found the revised velocity prediction to be in agreement with experiment. Projecting to the ITER baseline scenario, this model predicts a value for the pedestal-top rotation (ρ 0.9) comparable to 4 kRad/s. Using the theory modeled - and now tested - velocity to predict the bulk plasma rotation opens up a path to more confidently projecting the confinement and stability in ITER. Supported by the US DOE under DE-AC02-09CH11466 and DE-FC02-04ER54698.

[Interaction Between Occupational Vanadium Exposure and hsp70-hom on Neurobehavioral Function].

PubMed

Zhang, Qin; Liu, Yun-xing; Cui, Li; Li, Shun-pin; Gao, Wei; Hu, Gao-lin; Zhang, Zu-hui; Lan, Ya-jia

2016-01-01

In determine the effect of heat shock protein 70-hom gene (hsp70-hom) polymorphism on the neurobehavioral function of workers exposed to vanadium. Workers from the vanadium products and chemical industry were recruited by cluster sampling. Demographic data and exposure information were collected using a questionnaire. Neurobehavioral function was assessed by Neurobehavioral Core Test Battery. The hsp70-hom genotype was detected by restricted fragment length polymorphism-polymerase chain reaction (RFLP-PCR). A neurobehavioral index (NBI) was formulated through principal component analysis. Workers with a T/C genotype had worse performance in average reaction time, visual retention, digital span (backward), Santa Ana aiming (non-habitual hand), pursuit aiming (right points, total points), digit symbol and NBI score than others (P < 0.05). The relative risk of abnormal NBI score of the workers with a T/C genotype was 1.748 fold of those with a T/T genotype. The relative risk of abnormal.NBI score of the workers exposed to vanadium was 3.048 fold of controls (P < 0.05). But after adjustment with age and education, only vanadium exposure appeared with a significant effect on NBI score. When gene polymorphism and vanadium exposure coexisted, the effect of vanadium on neurobehavioral function was attenuated, but the influence of T/C genotype increased Codds ratio (OR = 4.577, P < 0.05). After adjustment with age and education, the OR of T/C genotype further increased to 7.777 (P < 0.05). Vanadium exposure and T/C genotype had.a bio-interaction effect on NBI score Crelative excess risk due to interaction (RERI) = 4.12, attributable proportion (AP) = 0.7, synergy index (S) = 6.45]. After adjustment with age and education, the RERI became 2.49 and the AP became 0.75, but no coefficient of interaction was produced. Priorities of occupational protection should be given to vanadium-exposed workers with a hsp70-hom T/C genotype and low education level.

Pharmacologic Characterization of Valbenazine (NBI-98854) and Its Metabolites.

PubMed

Grigoriadis, Dimitri E; Smith, Evan; Hoare, Sam R J; Madan, Ajay; Bozigian, Haig

2017-06-01

The vesicular monoamine transporter 2 (VMAT2) is an integral presynaptic protein that regulates the packaging and subsequent release of dopamine and other monoamines from neuronal vesicles into the synapse. Valbenazine (NBI-98854), a novel compound that selectively inhibits VMAT2, is approved for the treatment of tardive dyskinesia. Valbenazine is converted to two significant circulating metabolites in vivo, namely, (+)- α -dihydrotetrabenazine (R,R,R-HTBZ) and a mono-oxy metabolite, NBI-136110. Radioligand-binding studies were conducted to assess and compare valbenazine, tetrabenazine, and their respective metabolites in their abilities to selectively and potently inhibit [ 3 H]-HTBZ binding to VMAT2 in rat striatal, rat forebrain, and human platelet homogenates. A broad panel screen was conducted to evaluate possible off-target interactions of valbenazine, R,R,R-HTBZ, and NBI-136110 at >80 receptor, transporter, and ion channel sites. Radioligand binding showed R,R,R-HTBZ to be a potent VMAT2 inhibitor in homogenates of rat striatum (K i = 1.0-2.8 nM), rat forebrain (K i = 4.2 nM), and human platelets (K i = 2.6-3.3 nM). Valbenazine (K i = 110-190 nM) and NBI-136110 (K i = 160-220 nM) also exhibited inhibitory effects on VMAT2, but with lower potency than R,R,R-HTBZ. Neither valbenazine, R,R,R-HTBZ, nor NBI-136110 had significant off-target interactions at serotonin (5-HT 1A , 5-HT 2A , 5-HT 2B ) or dopamine (D 1 or D 2 ) receptor sites. In vivo studies measuring ptosis and prolactin secretion in the rat confirmed the specific and dose-dependent interactions of tetrabenazine and R,R,R-HTBZ with VMAT2. Evaluations of potency and selectivity of tetrabenazine and its pharmacologically active metabolites were also performed. Overall, the pharmacologic characteristics of valbenazine appear consistent with the favorable efficacy and tolerability findings of recent clinical studies [KINECT 2 (NCT01733121), KINECT 3 (NCT02274558)]. Copyright © 2017 by The Author(s).

Physics design of the injector source for ITER neutral beam injector (invited).

PubMed

Antoni, V; Agostinetti, P; Aprile, D; Cavenago, M; Chitarin, G; Fonnesu, N; Marconato, N; Pilan, N; Sartori, E; Serianni, G; Veltri, P

2014-02-01

Two Neutral Beam Injectors (NBI) are foreseen to provide a substantial fraction of the heating power necessary to ignite thermonuclear fusion reactions in ITER. The development of the NBI system at unprecedented parameters (40 A of negative ion current accelerated up to 1 MV) requires the realization of a full scale prototype, to be tested and optimized at the Test Facility under construction in Padova (Italy). The beam source is the key component of the system and the design of the multi-grid accelerator is the goal of a multi-national collaborative effort. In particular, beam steering is a challenging aspect, being a tradeoff between requirements of the optics and real grids with finite thickness and thermo-mechanical constraints due to the cooling needs and the presence of permanent magnets. In the paper, a review of the accelerator physics and an overview of the whole R&D physics program aimed to the development of the injector source are presented.

An Integrated Hydrological and Water Management Study of the Entire Nile River System - Lake Victoria to Nile Delta

NASA Technical Reports Server (NTRS)

Habib, Shahid; Zaitchik, Benjamin; Alo, Clement; Ozdogan, Mutlu; Anderson, Martha; Policelli, Fritz

2011-01-01

The Nile basin River system spans 3 million km(exp 2) distributed over ten nations. The eight upstream riparian nations, Ethiopia, Eretria, Uganda, Rwanda, Burundi, Congo, Tanzania and Kenya are the source of approximately 86% of the water inputs to the Nile, while the two downstream riparian countries Sudan and Egypt, presently rely on the river's flow for most of the their needs. Both climate and agriculture contribute to the complicated nature of Nile River management: precipitation in the headwaters regions of Ethiopia and Lake Victoria is variable on a seasonal and inter-annual basis, while demand for irrigation water in the arid downstream region is consistently high. The Nile is, perhaps, one of the most difficult trans-boundary water issue in the world, and this study would be the first initiative to combine NASA satellite observations with the hydrologic models study the overall water balance in a to comprehensive manner. The cornerstone application of NASA's Earth Science Research Results under this project are the NASA Land Data Assimilation System (LDAS) and the USDA Atmosphere-land Exchange Inverse (ALEXI) model. These two complementary research results are methodologically independent methods for using NASA observations to support water resource analysis in data poor regions. Where an LDAS uses multiple sources of satellite data to inform prognostic simulations of hydrological process, ALEXI diagnoses evapotranspiration and water stress on the basis of thermal infrared satellite imagery. Specifically, this work integrates NASA Land Data Assimilation systems into the water management decision support systems that member countries of the Nile Basin Initiative (NBI) and Regional Center for Mapping of Resources for Development (RCMRD, located in Nairobi, Kenya) use in water resource analysis, agricultural planning, and acute drought response to support sustainable development of Nile Basin water resources. The project is motivated by the recognition that accurate, frequent, and spatially distributed estimates of the water balance are necessary for effective water management. This creates a challenge for watersheds that are large, include data poor regions, and/or span multiple nations. All of these descriptors apply to the Nile River basin, yet successful management of the Nile is critical for development and political stability in the region. For this reason, improved hydrological data to support cooperative water management in the Nile basin is a priority for USAID, the US State Department, the World Bank and other international organizations. In this project, the U.S. based research team is working with partners at RCMRD, Nile Basin Initiative (NBI), and their member national-level agencies to develop satellite-based land cover maps, satellite-derived evapotranspiration estimates (using the ALEXI algorithm), and NASA's Land Data Assimilation System (LDAS) customized to match identified information needs. The cornerstone applied sciences product of the project is the development of a customized "Nile LDAS" that will produce optimal estimates of hydrological states and fluxes, as vetted against the in situ observations of NBI and RCMRD member organizations and independent satellite-derived hydrological estimates. Nile LDAS will be applied to improve the reliability of emerging Decision Support Systems in applications that include drought monitoring, reservoir management, and irrigation planning. The end-users such as RCMRD, NBI, Ethiopian and Kenya Meteorological and Famine Early Warning System Network (FEWSNet) will be the eventual benefactors of this work. There will be a capacity building process involving the above end-user organizations and transfer the models and the results for these organizations to execute for future use. The team has already initiated this study and the early results of first years' work are shown. The plan is to complete this work by late 2013.

Development of neutral beam injection system by use of washer gun plasma source

NASA Astrophysics Data System (ADS)

Imanaka, Heizo; Kajiya, Hirotaka; Nemoto, Yuichi; Azuma, Akiyoshi; Asai, Tomoaki; Yamada, Takuma; Inomoto, Michiaki; Ono, Yasushi

2008-11-01

For the past ten years, we have been investigating high-beta Spherical Tokamaks (ST) formation using reconnection heating of their axial merging in the TS-4 experiment, University of Tokyo. The produced ST was observed to have the maximum beta of 50-60% right after the merging of two STs. A key issue after the formation is to maintain the produced high-beta ST over 100 Alfven times for its stability check. A new low-cost pulsed neutral beam injection (NBI) system has been arranged for its sustainment experiment. Its advantages are 1) low voltage (15kV for low-field side of ST) and high current (20A), 2) maintenance-free, 3) low-cost. The conventional filament plasma source was replaced by the washer gun to realize air-cooled and maintenance free NBI system. In its startup experiment, we already extracted the maximum beam current of 3.7A for then acceleration voltage of 10kV successfully. This result suggests that the increase in the acceleration voltage and several conditioning work will realize its designed beam parameters of 15kV, 20A.

Image segmentation of pyramid style identifier based on Support Vector Machine for colorectal endoscopic images.

PubMed

Okamoto, Takumi; Koide, Tetsushi; Sugi, Koki; Shimizu, Tatsuya; Anh-Tuan Hoang; Tamaki, Toru; Raytchev, Bisser; Kaneda, Kazufumi; Kominami, Yoko; Yoshida, Shigeto; Mieno, Hiroshi; Tanaka, Shinji

2015-08-01

With the increase of colorectal cancer patients in recent years, the needs of quantitative evaluation of colorectal cancer are increased, and the computer-aided diagnosis (CAD) system which supports doctor's diagnosis is essential. In this paper, a hardware design of type identification module in CAD system for colorectal endoscopic images with narrow band imaging (NBI) magnification is proposed for real-time processing of full high definition image (1920 × 1080 pixel). A pyramid style image segmentation with SVMs for multi-size scan windows, which can be implemented on an FPGA with small circuit area and achieve high accuracy, is proposed for actual complex colorectal endoscopic images.

Screening Libraries of Semifluorinated Arylene Bisimides to Discover and Predict Thermodynamically Controlled Helical Crystallization.

PubMed

Ho, Ming-Shou; Partridge, Benjamin E; Sun, Hao-Jan; Sahoo, Dipankar; Leowanawat, Pawaret; Peterca, Mihai; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Ungar, Goran; Heiney, Paul A; Hsu, Chain-Shu; Percec, Virgil

2016-12-12

Synthesis, structural, and retrostructural analysis of a library containing 16 self-assembling perylene (PBI), 1,6,7,12-tetrachloroperylene (Cl 4 PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environmentally friendly AB 3 chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds, permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures. Thermodynamically controlled helical crystallization was discovered for propeller-like PBI, Cl 4 PBI and NBI with m = 0. Unexpectedly, assemblies of twisted Cl 4 PBIs exhibit higher order than those of planar PBIs. PBI with m = 1, 2, and 3 form a thermodynamically controlled columnar hexagonal 2D lattice of tilted helical columns with intracolumnar order. PBI and Cl 4 PBI with m = 1 crystallize via a recently discovered helical cogwheel mechanism, while NBI and PMBI with m = 1 form tilted helical columns. PBI, NBI and PMBI with m = 2 generate lamellar-like structures. 3D and 2D assemblies of PBI with m = 1, 2, and 3, NBI with m = 1 and PMBI with m = 2 exhibit 3.4 Å π-π stacking. The library approach applied here and in previous work enabled the discovery of six assemblies which self-organize via thermodynamic control into 3D and 2D periodic arrays, and provides molecular principles to predict the supramolecular structure of electronically active components.

Observations of ELM stabilization during neutral beam injection in DIII-D

NASA Astrophysics Data System (ADS)

Bortolon, Alessandro; Kramer, Gerrit; Diallo, Ahmed; Knolker, Matthias; Maingi, Rajesh; Nazikian, Raffi; Degrassie, John; Osborne, Thomas

2017-10-01

Edge localized modes (ELMs) are generally interpreted as peeling-ballooning instabilities, driven by the pedestal current and pressure gradient, with other subdominant effects possibly relevant close to marginal stability. We report observations of transient stabilization of type-I ELMs during neutral beam injection (NBI), emerging from a combined dataset of DIII-D ELMy H-mode plasmas with moderate heating obtained through pulsed NBI waveforms. Statistical analysis of ELM onset times indicates that, in the selected dataset, the likelihood of onset of an ELM lowers significantly during NBI modulation pulses, with the stronger correlation found with counter-current NBI. The effect is also found in rf-heated H-modes, where ELMs appear inhibited when isolated diagnostic beam pulses are applied. Coherent average analysis is used to determine how plasma density, temperature, rotation as well as beam ion quantities evolve during a NB modulation cycle, finding relatively small changes ( 3%) of pedestal Te and ne and toroidal and poloidal rotation variations up to 5 km/s. The effect of these changes on pedestal stability will be discussed. Work supported by US DOE under DE-FC02-04ER54698, DE-AC02-09CH11466.

SOL and Edge Flows in DIII-D

NASA Astrophysics Data System (ADS)

Boedo, J. A.; Degrassie, J. S.; Grierson, B. A.; Rudakov, D. A.

2015-11-01

Recent measurements at DIII-D edge plasmas at the outer midplane show that, in the absence of external torque, the edge and near-SOL plasma flow is largely dominated by the intrinsic source of rotation most likely due to thermal ion loss. We also show that when NBI heating is present, the core momentum competes with the edge intrinsic momentum and can overwhelm it, in short, NBI-heated discharges at high power tend to determine edge and near SOL flows. Experiments performed in the DIII-D tokamak with OH heated, ECH-heated and NBI-heated discharges are diagnosed for core plasma flow with CER and edge/SOL plasma flow with Mach probes. We have changed the amount of NBI, OH and ECH heating while scanning the discharge collisionality. We have compared the experimental measurements to two complementary thermal ion loss theories that explain most of the observed features, including a scaling with Ti. One theory considers passing and trapped particles that are lost via a loss cone purely due to drifts and the other considers turbulence-enhanced loss of passing particles. Work supported by the US DOE under DE-FC02-04ER54698, DE-FG02-07ER54917 and DE-AC02-09CH111466.

Usefulness of Demarcation of Differentiated-Type Early Gastric Cancers after Helicobacter pylori Eradication by Magnifying Endoscopy with Narrow-Band Imaging.

PubMed

Akazawa, Yoichi; Ueyama, Hiroya; Yao, Takashi; Komori, Hiroyuki; Takeda, Tsutomu; Matsumoto, Kohei; Matsumoto, Kenshi; Asaoka, Daisuke; Hojo, Mariko; Watanabe, Sumio; Nagahara, Akihito

2018-06-05

Early gastric cancer after Helicobacter pylori (Hp) eradication is difficult to demarcate. We used the vessel plus surface classification system (VSCS) to determine whether magnifying endoscopy with narrow-band imaging (ME-NBI) could demarcate differentiated-type early gastric cancers after Hp eradication, and to identify causes of an unclear demarcation line (DL). Among 100 lesions of differentiated-type early gastric cancer resected endoscopically, 34 lesions in the Hp-eradicated group and 66 in the Hp-infected group were retrospectively compared. Clinicopathological factors and ME-NBI findings, including the presence or absence of the DL, were examined. Histopathologically, histological gastritis, the surface structure at the tumor border, well-differentiated adenocarcinoma with low-grade atypia (tub1-low), and non-neoplastic epithelium (NE) coverage rate on the tumor surface and at the tumor border were evaluated. DL (-) cases were more frequent in the Hp-eradicated group (11.8%, 4/34) than in the Hp-infected group (1.5%, 1/66; p < 0.05). The Hp-eradicated group had a higher NE coverage rate than the Hp-infected group (p < 0.05). All DL (-) cases had tub1-low or NE at the tumor border. ME-NBI with VSCS can identify the DL in most patients (88.2%) with differentiated-type early gastric cancer after Hp eradication. © 2018 S. Karger AG, Basel.

Diagnostic Performance of Narrow Band Imaging for Nasopharyngeal Cancer: A Systematic Review and Meta-analysis.

PubMed

Sun, Changling; Zhang, Yayun; Han, Xue; Du, Xiaodong

2018-03-01

Objective The purposes of this study were to verify the effectiveness of the narrow band imaging (NBI) system in diagnosing nasopharyngeal cancer (NPC) as compared with white light endoscopy. Data Sources PubMed, Cochrane Library, EMBASE, CNKI, and Wan Fang databases. Review Methods Data analyses were performed with Meta-Disc. The updated Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality and potential bias. Publication bias was assessed with a Deeks asymmetry test. The registry number of the protocol published on PROSPERO is CRD42015026244. Results This meta-analysis included 10 studies of 1337 lesions. For NBI diagnosis of NPC, the pooled values were as follows: sensitivity, 0.83 (95% CI, 0.80-0.86); specificity, 0.91 (95% CI, 0.89-0.93); positive likelihood ratio, 8.82 (95% CI, 5.12-15.21); negative likelihood ratio, 0.18 (95% CI, 0.12-0.27); and diagnostic odds ratio, 65.73 (95% CI, 36.74-117.60). The area under the curve was 0.9549. For white light endoscopy in diagnosing NPC, the pooled values were as follows: sensitivity, 0.79 (95% CI, 0.75-0.83); specificity, 0.87 (95% CI, 0.84-0.90); positive likelihood ratio, 5.02 (95% CI, 1.99-12.65); negative likelihood ratio, 0.34 (95% CI, 0.24-0.49); and diagnostic odds ratio, 16.89 (95% CI, 5.98-47.66). The area under the curve was 0.8627. The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I 2 of 0.326. No marked publication bias ( P = .68) existed in this meta-analysis. Conclusion The sensitivity and specificity of NBI for the diagnosis of NPC are similar to those of white light endoscopy, and the potential value of NBI for the diagnosis of NPC needs to be validated further.

A blue optical filter for narrow-band imaging in endoscopic capsules

NASA Astrophysics Data System (ADS)

Silva, M. F.; Ghaderi, M.; Goncalves, L. M.; de Graaf, G.; Wolffenbuttel, R. F.; Correia, J. H.

2014-05-01

This paper presents the design, simulation, fabrication, and characterization of a thin-film Fabry-Perot resonator composed of titanium dioxide (TiO2) and silicon dioxide (SiO2) thin-films. The optical filter is developed to be integrated with a light emitting diode (LED) for enabling narrow-band imaging (NBI) in endoscopy. The NBI is a high resolution imaging technique that uses spectrally centered blue light (415 nm) and green light (540 nm) to illuminate the target tissue. The light at 415 nm enhances the imaging of superficial veins due to their hemoglobin absorption, while the light at 540 nm penetrates deeper into the mucosa, thus enhances the sub-epithelial vessels imaging. Typically the endoscopes and endoscopic capsules use white light for acquiring images of the gastrointestinal (GI) tract. However, implementing the NBI technique in endoscopic capsules enhances their capabilities for the clinical applications. A commercially available blue LED with a maximum peak intensity at 404 nm and Full Width Half Maximum (FWHM) of 20 nm is integrated with a narrow band blue filter as the NBI light source. The thin film simulations show a maximum spectral transmittance of 36 %, that is centered at 415 nm with FWHM of 13 nm for combined the blue LED and a Fabry Perot resonator system. A custom made deposition scheme was developed for the fabrication of the blue optical filter by RF sputtering. RF powered reactive sputtering at 200 W with the gas flows of argon and oxygen that are controlled for a 5:1 ratio gives the optimum optical conditions for TiO2 thin films. For SiO2 thin films, a non-reactive RF sputtering at 150 W with argon gas flow at 15 sccm results in the best optical performance. The TiO2 and SiO2 thin films were fully characterized by an ellipsometer in the wavelength range between 250 nm to 1600 nm. Finally, the optical performance of the blue optical filter is measured and presented.

Performance of the BATMAN RF source with a large racetrack shaped driver

NASA Astrophysics Data System (ADS)

Kraus, W.; Schiesko, L.; Wimmer, C.; Fantz, U.; Heinemann, B.

2017-08-01

In the negative ion sources in neutral beam injection systems (NBI) of future fusion reactors the plasma is generated in up to eight cylindrical RF sources ("drivers") from which it expands into the main volume. For these large sources, in particular those used in the future DEMO NBI, a high RF efficiency and operational reliability is required. To achieve this it could be favorable to substitute each pair of drivers by one larger one. To investigate this option the cylindrical driver of the BATMAN source at IPP Garching has been replaced by a large source with a racetrack shaped base area and tested using the same extraction system. The main differences are a five times larger source volume and another position of the Cs oven which is mounted onto the driver`s back plate and not onto the expansion volume. The conditioning characteristics and the plasma symmetry in front of the plasma grid were very similar. The extracted H- current densities jex are comparable to that achieved with the small driver at the same power. Because no saturation of jex occurred at 0.6 Pa at high power and the source allows high power operation, a maximum value 45.1 mA/cm2 at 103 kW has been reached. Sputtered Cu from the walls of the expansion volume affected the performance at low pressure, particularly in deuterium. The experiments will be therefore continued with Mo coating of all inner walls.

Sawtooth control in fusion plasmas

NASA Astrophysics Data System (ADS)

Graves, J. P.; Angioni, C.; Budny, R. V.; Buttery, R. J.; Coda, S.; Eriksson, L.-G.; Gimblett, C. G.; Goodman, T. P.; Hastie, R. J.; Henderson, M. A.; Koslowski, H. R.; Mantsinen, M. J.; Martynov, An; Mayoral, M.-L.; Mück, A.; Nave, M. F. F.; Sauter, O.; Westerhof, E.; Contributors, JET–EFDA

2005-12-01

Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth.

Young Prehistoric Kilauea Lava Flows From Uwekahuna Bluff, Hawaii: Mixed Source or Hybrid Magmas?

NASA Astrophysics Data System (ADS)

Marske, J. P.; Pietruszka, A. J.; Garcia, M. O.; Norman, M. D.; Rhodes, J. M.

2004-12-01

For the last 350 kyr, nearly the entire known compositional range of subaerial and submarine Kilauea lavas lie within the range defined by the volcano's historical eruptions. In contrast, Rhodes et al. (1989) discovered that some Kilauea lavas have Mauna Loa-like major-and trace-element signatures and concluded that Mauna Loa magmas may periodically invade Kilauea's shallow plumbing system. Here, we present new major- and trace- element data for 25 sequential prehistoric lava flows (0.5 to <2 ka) from the upper 55 m of the north wall of Kilauea caldera at Uwekahuna Bluff (UB). Although historical Kilauea and Mauna Loa lavas have been compositionally distinct for most of the last 230 kyr, our results show that the UB lavas span the geochemical spectrum between these neighboring volcanoes. At a given MgO content, the abundances of major elements (e.g., SiO2, TiO2, or CaO) in the UB lavas typically plot between historical Mauna Loa and Kilauea values, suggesting that these lavas originated from compositionally intermediate parental magmas or from hybridization between historical Kilauea- and Mauna Loa-type magmas. In contrast to the major element abundances, ratios of highly to moderately incompatible elements (e.g., Nb/Y) in the UB lavas are mostly Mauna Loa-like. These incompatible trace element ratios reveal a rapid fluctuation of Kilauea's lava composition since prehistoric times: (1) two lava flows at the base of the suite record a decrease in Nb/Y from historical Kilauea- to historical Mauna Loa-type values, (2) a weathered hiatus near the middle of the flow sequence coincides with a gradual Nb/Y minimum and reversal, and (3) the top three lava flows transition back into historical Kilauea-type Nb/Y values with a smooth temporal connection to the oldest historical lavas from this volcano. The systematic variations of these UB trace-element ratios may result from gradual mixing between Kilauea- and Mauna Loa-type magmas within the summit reservoir and/or varying degrees of partial melting of a Mauna Loa-like mantle heterogeneity within Kilauea's source region. Highly incompatible element ratios (e.g., Rb/Nb), which are typically unaffected by variable melt fraction, indicate that changes in the degree of partial melting alone cannot explain these Mauna Loa-like lava flows. Pb, Sr and Nd isotopic ratios of the Uwekahuna Bluff lavas will be presented to differentiate mantle source and melting effects from magma chamber processes.

Diagnostic Performance of Narrow Band Imaging for Laryngeal Cancer: A Systematic Review and Meta-analysis.

PubMed

Sun, Changling; Han, Xue; Li, Xiaoying; Zhang, Yayun; Du, Xiaodong

2017-04-01

Objective To evaluate the performance of narrow band imaging (NBI) for the diagnosis of laryngeal cancer and to compare the diagnostic value of NBI with that of white light endoscopy. Data Sources PubMed, Embase, Cochrane Library, and CNKI databases. Review Methods Data analyses were performed with Meta-DiSc. The updated Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality and potential bias. Publication bias was assessed with the Deeks's asymmetry test. The protocol used in this article has been published on PROSPERO and is in accordance with the PRISMA checklist. The registry number for this study is CRD42015025866. Results Six studies including 716 lesions were included in this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio for the NBI diagnosis of laryngeal cancer were 0.94 (95% confidence interval [95% CI]: 0.91-0.96), 0.89 (95% CI: 0.85-0.92), and 142.12 (95% CI: 46.42-435.15), respectively, and the area under receiver operating characteristics curve was 0.97. Among the 6 studies, 3 evaluated the diagnostic value of white light endoscopy, with a sensitivity of 0.81 (95% CI: 0.76-0.86), a specificity of 0.92 (95% CI: 0.88-0.95), and a diagnostic odds ratio of 33.82 (95% CI: 14.76-77.49). The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I 2 of 66%. No marked publication bias ( P = .84) was detected in this meta-analysis. Conclusion The sensitivity of NBI is superior to white light endoscopy, and the potential value of NBI needs to be validated in future studies.

No effect of the altered peptide ligand NBI-6024 on beta-cell residual function and insulin needs in new-onset type 1 diabetes.

PubMed

Walter, Markus; Philotheou, Areti; Bonnici, François; Ziegler, Anette-G; Jimenez, Roland

2009-11-01

This randomized, four-arm, placebo-controlled, dose-ranging phase 2 trial was conducted to determine whether repeated subcutaneous injections of the altered peptide ligand, NBI-6024, designed to inhibit autoreactive T-cells, improves beta-cell function in patients with recently diagnosed type 1 diabetes. A total of 188 patients, aged 10-35 years, with recently diagnosed type 1 diabetes were randomly assigned for a treatment consisting of the subcutaneous administration of placebo or 1, 0.5, or 0.1 mg NBI-6024 at baseline, weeks 2 and 4, and then monthly until month 24. Fasting, peak, and area under the curve (AUC) C-peptide concentrations during a 2-h mixed-meal tolerance test were measured at 3-month intervals during treatment. Immune function parameters (islet antibodies and CD4 and CD8 T-cells) were also studied. The mean peak C-peptide concentration at 24 months after study entry showed no significant difference between the groups treated with 0.1 mg (0.59 pmol/ml), 0.5 mg (0.57 pmol/ml), and 1.0 mg NBI-6024 (0.48 pmol/ml) and the placebo group (0.54 pmol/ml). Fasting, stimulated peak, and AUC C-peptide concentrations declined linearly in all groups by approximately 60% over the 24-month treatment period. The average daily insulin needs at month 24 were also comparable between the four groups. No treatment-related changes in islet antibodies and T cell numbers were observed. Treatment with altered peptide ligand NBI-6024 at repeated doses of 0.1, 0.5, or 1.0 mg did not improve or maintain beta-cell function.

Potential Application of a Graphical Processing Unit to Parallel Computations in the NUBEAM Code

NASA Astrophysics Data System (ADS)

Payne, J.; McCune, D.; Prater, R.

2010-11-01

NUBEAM is a comprehensive computational Monte Carlo based model for neutral beam injection (NBI) in tokamaks. NUBEAM computes NBI-relevant profiles in tokamak plasmas by tracking the deposition and the slowing of fast ions. At the core of NUBEAM are vector calculations used to track fast ions. These calculations have recently been parallelized to run on MPI clusters. However, cost and interlink bandwidth limit the ability to fully parallelize NUBEAM on an MPI cluster. Recent implementation of double precision capabilities for Graphical Processing Units (GPUs) presents a cost effective and high performance alternative or complement to MPI computation. Commercially available graphics cards can achieve up to 672 GFLOPS double precision and can handle hundreds of thousands of threads. The ability to execute at least one thread per particle simultaneously could significantly reduce the execution time and the statistical noise of NUBEAM. Progress on implementation on a GPU will be presented.

Regeneration and tritium recovery from the large JET neutral injection cryopump system after the FTE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obert, W.; Bell, A.; Davies, J.

1992-12-01

Neutral Beam Injection (NBI) was used to introduce tritium into the plasma for the First Tritium Experiment In addition to the decisive advantage of depositing the tritium into the centre of the plasma, the use of NBI also minimized the total quantity of tritium introduced into the Torus and the contamination of the vacuum vessel. However, because of the relatively low gas efficiency of the positive ion injection system approximately 95% of the total quantity of tritium introduced was pumped by the large condensation cryopumps which form an integral part of the injector. Several hardware and associated software changes weremore » implemented in order to making provision for possible fault scenarios during operation with tritium and to ensure complete regeneration of the tritium from the cryopumps. The tritium released after all subsequent regeneration`s has been monitored carefully in order to determine the amount of tritium retained by the black anodized liquid nitrogen panel surfaces of the cryopump and to compare it with experiments at TSTA on JET samples before the FTE.« less

Regeneration and tritium recovery from the large JET neutral injection cryopump system after the FTE. [First Tritium Experiment (FTE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obert, W.; Bell, A.; Davies, J.

1992-01-01

Neutral Beam Injection (NBI) was used to introduce tritium into the plasma for the First Tritium Experiment In addition to the decisive advantage of depositing the tritium into the centre of the plasma, the use of NBI also minimized the total quantity of tritium introduced into the Torus and the contamination of the vacuum vessel. However, because of the relatively low gas efficiency of the positive ion injection system approximately 95% of the total quantity of tritium introduced was pumped by the large condensation cryopumps which form an integral part of the injector. Several hardware and associated software changes weremore » implemented in order to making provision for possible fault scenarios during operation with tritium and to ensure complete regeneration of the tritium from the cryopumps. The tritium released after all subsequent regeneration's has been monitored carefully in order to determine the amount of tritium retained by the black anodized liquid nitrogen panel surfaces of the cryopump and to compare it with experiments at TSTA on JET samples before the FTE.« less

Perturbative studies of toroidal momentum transport in KSTAR H-mode and the effect of ion temperature perturbation

NASA Astrophysics Data System (ADS)

Yang, S. M.; Na, Yong-Su; Na, D. H.; Park, J.-K.; Shi, Y. J.; Ko, W. H.; Lee, S. G.; Hahm, T. S.

2018-06-01

Perturbative experiments have been carried out using tangential neutral beam injection (NBI) and non-resonant magnetic perturbation (NRMP) to analyze the momentum transport properties in KSTAR H-modes. Diffusive and non-diffusive terms of momentum transport are evaluated from the transient analysis. Although the operating conditions and methodologies applied in the two cases are similar, the momentum transport properties obtained show clear differences. The estimated momentum diffusivity and pinch obtained in the NBI modulation experiments is larger than that in the NRMP modulation experiments. We found that this discrepancy could be a result of uncertainties in the assumption for the analysis. By introducing time varying momentum transport coefficients depending on the temperature gradient, the linearized equation shows that if the temperature perturbation exists, the evolution of toroidal rotation perturbation could be faster than the transport rate of mean quantity, since the evolution of toroidal rotation perturbation is related to , a momentum diffusivity from perturbative analysis. This could explain the estimated higher momentum diffusivity using time independent transport coefficients in NBI experiments with higher ion temperature perturbation compared to that in NRMP modulation experiments. The differences in the momentum transport coefficient with NRMP and NBI are much reduced by considering time varying momentum transport coefficients in the time dependent transport simulation.

Intraoperative narrow band imaging better delineates superficial resection margins during transoral laser microsurgery for early glottic cancer.

PubMed

Garofolo, Sabrina; Piazza, Cesare; Del Bon, Francesca; Mangili, Stefano; Guastini, Luca; Mora, Francesco; Nicolai, Piero; Peretti, Giorgio

2015-04-01

The high rate of positive margins after transoral laser microsurgery (TLM) remains a matter of debate. This study investigates the effect of intraoperative narrow band imaging (NBI) examination on the incidence of positive superficial surgical margins in early glottic cancer treated by TLM. Between January 2012 and October 2013, 82 patients affected by Tis-T1a glottic cancer were treated with TLM by type I or II cordectomies. Intraoperative NBI evaluation was performed using 0-degree and 70-degree rigid telescopes. Surgical specimens were oriented by marking the superior edge with black ink and sent to a dedicated pathologist. Comparison between the rate of positive superficial margins in the present cohort and in a matched historical control group treated in the same way without intraoperative NBI was calculated by chi-square test. At histopathological examination, all surgical margins were negative in 70 patients, whereas 7 had positive deep margins, 2 close, and 3 positive superficial margins. The rate of positive superficial margins was thus 3.6% in the present group and 23.7% in the control cohort (P<.001). Routine use of intraoperative NBI increases the accuracy of neoplastic superficial spreading evaluation during TLM for early glottic cancer. © The Author(s) 2014.

A preliminary investigation of the effects of the unified protocol on temperament.

PubMed

Carl, Jenna R; Gallagher, Matthew W; Sauer-Zavala, Shannon E; Bentley, Kate H; Barlow, David H

2014-08-01

Previous research has shown that two dimensions of temperament referred to as neuroticism/behavioral inhibition (N/BI) and extraversion/behavioral activation (E/BA) are key risk factors in the development and maintenance of anxiety and mood disorders (Brown & Barlow, 2009). Given such findings, these temperamental dimensions may represent promising treatment targets for individuals with emotional disorders; however, to date, few studies have investigated the effects of psychological treatments on temperamental constructs generally assumed to be "stable, inflexible, and pervasive" (American Psychiatric Association, 2000). The present study addresses this gap in the literature by examining the effects of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP; Barlow et al., 2011), a cognitive-behavioral therapy designed to target core processes of N/BI and E/BA temperaments, in a sample of adults with principal anxiety disorders and a range of comorbid conditions. Results revealed small effects of the UP on N/BI and E/BA compared with a waitlist control group at post-treatment. Additionally, decreases in N/BI and increases in E/BA during treatment were associated with improvements in symptoms, functioning, and quality of life. Findings provide preliminary support for the notion that the UP treatment facilitates beneficial changes in dimensions of temperament. Copyright © 2014 Elsevier Inc. All rights reserved.

A wireless narrowband imaging chip for capsule endoscope.

PubMed

Lan-Rong Dung; Yin-Yi Wu

2010-12-01

This paper presents a dual-mode capsule gastrointestinal endoscope device. An endoscope combined with a narrowband image (NBI), has been shown to be a superior diagnostic tool for early stage tissue neoplasms detection. Nevertheless, a wireless capsule endoscope with the narrowband imaging technology has not been presented in the market up to now. The narrowband image acquisition and power dissipation reduction are the main challenges of NBI capsule endoscope. In this paper, we present the first narrowband imaging capsule endoscope that can assist clinical doctors to effectively diagnose early gastrointestinal cancers, profited from our dedicated dual-mode complementary metal-oxide semiconductor (CMOS) sensor. The dedicated dual-mode CMOS sensor can offer white-light and narrowband images. Implementation results show that the proposed 512 × 512 CMOS sensor consumes only 2 mA at a 3-V power supply. The average current of the NBI capsule with an 8-Mb/s RF transmitter is nearly 7 ~ 8 mA that can continuously work for 6 ~ 8 h with two 1.5-V 80-mAh button batteries while the frame rate is 2 fps. Experimental results on backside mucosa of a human tongue and pig's small intestine showed that the wireless NBI capsule endoscope can significantly improve the image quality, compared with a commercial-of-the-shelf capsule endoscope for gastrointestinal tract diagnosis.

Pilot study on probe-based confocal laser endomicroscopy for colorectal neoplasms: an initial experience in Japan.

PubMed

Abe, Seiichiro; Saito, Yutaka; Oono, Yasuhiro; Tanaka, Yusaku; Sakamoto, Taku; Yamada, Masayoshi; Nakajima, Takeshi; Matsuda, Takahisa; Ikematsu, Hiroaki; Yano, Tomonori; Sekine, Shigeki; Kojima, Motohiro; Yamagishi, Hidetsugu; Kato, Hiroyuki

2018-04-26

The aim of this pilot study is to investigate the diagnostic yield of probe-based confocal laser endomicroscopy (pCLE) in the evaluation of depth of invasion in colorectal lesions. Patients with colorectal lesions eligible for either endoscopic treatment or surgery were enrolled in the study. Tumor's depth of invasion was classified as mucosal or slight submucosal (M-SM1) and deep submucosal invasion or deeper (SM2 or deeper). White light endoscopy (WLE), magnifying narrow band imaging (M-NBI), and magnifying chromoendoscopy (M-CE) were used to assess colorectal lesions, and pCLE was used to identify tumor's features related to SM2 or deeper. The diagnostic classification of depth of invasion was obtained by correlating pCLE findings with histology results (on-site diagnosis). All colorectal lesions were stratified by a second endoscopist who was blinded to any clinical and histological information with the use of WLE, M-NBI, M-CE, and pCLE (off-line review). A total of 22 colorectal lesions were analyzed: seven were adenoma, ten intramucosal cancer, and five SM2 or deeper cancer. With respect to pCLE findings, loss of crypt structure was seen in all SM2 or deeper cancers and only in one M-SM1 lesion. Sensitivity, specificity, and accuracy of WLE, M-NBI, and M-CE in off-line review were 60/94/86, 60/94/86, and 80/94/91%, respectively. Sensitivity/specificity/accuracy of pCLE in off-line review were 80/94/91%, respectively. The inter-observer agreement of pCLE between on-site diagnosis and off-line review was 0.64 (95%CI 0.27-1.0). pCLE may represent a useful tool to evaluate the depth of invasion in colorectal lesions.

Monte Carlo modeling of light-tissue interactions in narrow band imaging.

PubMed

Le, Du V N; Wang, Quanzeng; Ramella-Roman, Jessica C; Pfefer, T Joshua

2013-01-01

Light-tissue interactions that influence vascular contrast enhancement in narrow band imaging (NBI) have not been the subject of extensive theoretical study. In order to elucidate relevant mechanisms in a systematic and quantitative manner we have developed and validated a Monte Carlo model of NBI and used it to study the effect of device and tissue parameters, specifically, imaging wavelength (415 versus 540 nm) and vessel diameter and depth. Simulations provided quantitative predictions of contrast-including up to 125% improvement in small, superficial vessel contrast for 415 over 540 nm. Our findings indicated that absorption rather than scattering-the mechanism often cited in prior studies-was the dominant factor behind spectral variations in vessel depth-selectivity. Narrow-band images of a tissue-simulating phantom showed good agreement in terms of trends and quantitative values. Numerical modeling represents a powerful tool for elucidating the factors that affect the performance of spectral imaging approaches such as NBI.

Modelling third harmonic ion cyclotron acceleration of deuterium beams for JET fusion product studies experiments

NASA Astrophysics Data System (ADS)

Schneider, M.; Johnson, T.; Dumont, R.; Eriksson, J.; Eriksson, L.-G.; Giacomelli, L.; Girardo, J.-B.; Hellsten, T.; Khilkevitch, E.; Kiptily, V. G.; Koskela, T.; Mantsinen, M.; Nocente, M.; Salewski, M.; Sharapov, S. E.; Shevelev, A. E.; Contributors, JET

2016-11-01

Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 (3He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) of the beam. This scenario generates a fast ion deuterium tail enhancing DD and D3He fusion reactions. Modelling and measuring the fast deuterium tail accurately is essential for quantifying the fusion products. This paper presents the modelling of the D distribution function resulting from the NBI+ICRF heating scheme, reinforced by a comparison with dedicated JET fast ion diagnostics, showing an overall good agreement. Finally, a sawtooth activity for these experiments has been observed and interpreted using SPOT/RFOF simulations in the framework of Porcelli’s theoretical model, where NBI+ICRH accelerated ions are found to have a strong stabilizing effect, leading to monster sawteeth.

First measurement of the edge charge exchange recombination spectroscopy on EAST tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Y. Y., E-mail: liyy@ipp.ac.cn; Fu, J.; Jiang, D.

2016-11-15

An edge toroidal charge exchange recombination spectroscopy (eCXRS) diagnostic, based on a heating neutral beam injection (NBI), has been deployed recently on the Experimental Advanced Superconducting Tokamak (EAST). The eCXRS, which aims to measure the plasma ion temperature and toroidal rotation velocity in the edge region simultaneously, is a complement to the exiting core CXRS (cCXRS). Two rows with 32 fiber channels each cover a radial range from ∼2.15 m to ∼2.32 m with a high spatial resolution of ∼5-7 mm. Charge exchange emission of Carbon VI CVI at 529.059 nm induced by the NBI is routinely observed, but canmore » be tuned to any interested wavelength in the spectral range from 400 to 700 nm. Double-slit fiber bundles increase the number of channels, the fibers viewing the same radial position are binned on the CCD detector to improve the signal-to-noise ratio, enabling shorter exposure time down to 5 ms. One channel is connected to a neon lamp, which provides the real-time wavelength calibration on a shot-to-shot basis. In this paper, an overview of the eCXRS diagnostic on EAST is presented and the first results from the 2015 experimental campaign will be shown. Good agreements in ion temperature and toroidal rotation are obtained between the eCXRS and cCXRS systems.« less

Synthetic neutron camera and spectrometer in JET based on AFSI-ASCOT simulations

NASA Astrophysics Data System (ADS)

Sirén, P.; Varje, J.; Weisen, H.; Koskela, T.; contributors, JET

2017-09-01

The ASCOT Fusion Source Integrator (AFSI) has been used to calculate neutron production rates and spectra corresponding to the JET 19-channel neutron camera (KN3) and the time-of-flight spectrometer (TOFOR) as ideal diagnostics, without detector-related effects. AFSI calculates fusion product distributions in 4D, based on Monte Carlo integration from arbitrary reactant distribution functions. The distribution functions were calculated by the ASCOT Monte Carlo particle orbit following code for thermal, NBI and ICRH particle reactions. Fusion cross-sections were defined based on the Bosch-Hale model and both DD and DT reactions have been included. Neutrons generated by AFSI-ASCOT simulations have already been applied as a neutron source of the Serpent neutron transport code in ITER studies. Additionally, AFSI has been selected to be a main tool as the fusion product generator in the complete analysis calculation chain: ASCOT - AFSI - SERPENT (neutron and gamma transport Monte Carlo code) - APROS (system and power plant modelling code), which encompasses the plasma as an energy source, heat deposition in plant structures as well as cooling and balance-of-plant in DEMO applications and other reactor relevant analyses. This conference paper presents the first results and validation of the AFSI DD fusion model for different auxiliary heating scenarios (NBI, ICRH) with very different fast particle distribution functions. Both calculated quantities (production rates and spectra) have been compared with experimental data from KN3 and synthetic spectrometer data from ControlRoom code. No unexplained differences have been observed. In future work, AFSI will be extended for synthetic gamma diagnostics and additionally, AFSI will be used as part of the neutron transport calculation chain to model real diagnostics instead of ideal synthetic diagnostics for quantitative benchmarking.

Conceptual design of the DEMO neutral beam injectors: main developments and R&D achievements

NASA Astrophysics Data System (ADS)

Sonato, P.; Agostinetti, P.; Bolzonella, T.; Cismondi, F.; Fantz, U.; Fassina, A.; Franke, T.; Furno, I.; Hopf, C.; Jenkins, I.; Sartori, E.; Tran, M. Q.; Varje, J.; Vincenzi, P.; Zanotto, L.

2017-05-01

The objectives of the nuclear fusion power plant DEMO, to be built after the ITER experimental reactor, are usually understood to lie somewhere between those of ITER and a ‘first of a kind’ commercial plant. Hence, in DEMO the issues related to efficiency and RAMI (reliability, availability, maintainability and inspectability) are among the most important drivers for the design, as the cost of the electricity produced by this power plant will strongly depend on these aspects. In the framework of the EUROfusion Work Package Heating and Current Drive within the Power Plant Physics and Development activities, a conceptual design of the neutral beam injector (NBI) for the DEMO fusion reactor has been developed by Consorzio RFX in collaboration with other European research institutes. In order to improve efficiency and RAMI aspects, several innovative solutions have been introduced in comparison to the ITER NBI, mainly regarding the beam source, neutralizer and vacuum pumping systems.

A feasibility study of a NBI photoneutralizer based on nonlinear gating laser recirculation

NASA Astrophysics Data System (ADS)

Fassina, A.; Pretato, F.; Barbisan, M.; Giudicotti, L.; Pasqualotto, R.

2016-02-01

The neutralization efficiency of negative ion neutral beam injectors is a major issue for future fusion reactors. Photon neutralization might be a valid alternative to present gas neutralizers, but still with several challenges for a valid implementation. Some concepts have been presented so far but none has been validated yet. A novel photoneutralization concept is discussed here, based on an annular cavity and a duplicated frequency laser beam (recirculation injection by nonlinear gating). The choice of lithium triborate as the material for the second harmonic extractor is discussed and a possible cooling method via crystal slicing is presented; laser intensity enhancement within the cavity is evaluated in order to quantify the achievable neutralization rate. Mockups of the critical components are proposed as intermediate steps toward system realization.

The add-on N-acetylcysteine is more effective than dimethicone alone to eliminate mucus during narrow-band imaging endoscopy: a double-blind, randomized controlled trial.

PubMed

Chen, Ming-Jen; Wang, Horng-Yuan; Chang, Chen-Wang; Hu, Kuang-Chun; Hung, Chien-Yuan; Chen, Chih-Jen; Shih, Shou-Chuan

2013-02-01

Recent studies have shown that pronase can improve mucosal visibility, but this agent is not uniformly available for human use worldwide. This study aimed to assess the efficacy of N-acetylcysteine (NAC), a mucolytic agent, in improving mucus elimination as measured by decreased endoscopic water flushes during narrow-band imaging (NBI) endoscopy. A consecutive series of patients scheduled for upper gastrointestinal endoscopy at outpatient clinics were enrolled in this double-blind, randomized controlled trial. The control group drank a preparation of 100 mg dimethicone (5 ml at 20 mg/ml) plus water up to 100 ml, and the NAC group drank 300 mg NAC plus 100 mg dimethicone and water up to 100 ml. During the endoscopy, the endoscopist used as many flushes of water as deemed necessary to produce a satisfactory NBI view of the entire gastric mucosa. In all, 177 patients with a mean age of 51 years were evaluated in this study. Significantly lesser water was used for flushing during NBI endoscopy for the NAC group than the control group; 40 ml (30-70, 0-120) versus 50 ml (30-100, 0-150) (median (interquartile range, range), p = 0.0095). Considering the safety profile of NAC, decreasing the number of water flushes for optimal vision and unavailability of pronase in some areas, the authors suggest the use of add-on NAC to eliminate mucus during NBI endoscopy.

Magnifying Endoscopy with Narrow Band Imaging of Early Gastric Cancer: Correlation with Histopathology and Mucin Phenotype

PubMed Central

Ok, Kyung-Sun; Kim, Gwang Ha; Park, Do Youn; Lee, Hyun Jeong; Jeon, Hye Kyung; Baek, Dong Hoon; Lee, Bong Eun; Song, Geun Am

2016-01-01

Background/Aims Magnifying endoscopy with narrow band imaging (ME-NBI) is a useful modality for the detailed visualization of microsurface (MS) and microvascular (MV) structures in the gastrointestinal tract. This study aimed to determine whether the MS and MV patterns in ME-NBI differ according to the histologic type, invasion depth, and mucin phenotype of early gastric cancers (EGCs). Methods The MS and MV patterns of 160 lesions in 160 patients with EGC who underwent ME-NBI before endoscopic or surgical resection were prospectively collected and analyzed. EGCs were categorized as either differentiated or undifferentiated and as either mucosal or submucosal, and their mucin phenotypes were determined via immunohistochemistry of the tumor specimens. Results Differentiated tumors mainly displayed an oval and/or tubular MS pattern and a fine network or loop MV pattern, whereas undifferentiated tumors mainly displayed an absent MS pattern and a corkscrew MV pattern. The destructive MS pattern was associated with submucosal invasion, and this association was more prominent in the differentiated tumors than in the undifferentiated tumors. MUC5AC expression was increased in lesions with either a papillary or absent MS pattern and a corkscrew MV pattern, whereas MUC6 expression was increased in lesions with a papillary MS pattern and a loop MV pattern. CD10 expression was more frequent in lesions with a fine network MV pattern. Conclusions ME-NBI can be useful for predicting the histopathology and mucin phenotype of EGCs. PMID:27021504

Investigation of mucosal pattern of gastric antrum using magnifying narrow-band imaging in patients with chronic atrophic fundic gastritis.

PubMed

Yamasaki, Yasushi; Uedo, Noriya; Kanzaki, Hiromitsu; Kato, Minoru; Hamada, Kenta; Aoi, Kenji; Tonai, Yusuke; Matsuura, Noriko; Kanesaka, Takashi; Yamashina, Takeshi; Akasaka, Tomofumi; Hanaoka, Noboru; Takeuchi, Yoji; Higashino, Koji; Ishihara, Ryu; Tomita, Yasuhiko; Iishi, Hiroyasu

2017-01-01

Magnifying narrow-band imaging (M-NBI) can reportedly help predict the presence and distribution of atrophy and intestinal metaplasia in the gastric corpus. However, the micro-mucosal pattern of the antrum shown by M-NBI differs from that of the corpus. We studied the distribution and histology of the micro-mucosal pattern in the antrum based on magnifying endoscopy. Endoscopic images of the greater curvature of the antrum were evaluated in 50 patients with chronic atrophic fundic gastritis (CAFG). The extent of CAFG was evaluated by autofluorescence imaging. The micro-mucosal pattern was evaluated by M-NBI and classified into groove and white villiform types. The localization of white villiform type mucosa was classified into three types in relation to the areae gastricae : null, central, and segmental types. Biopsies were taken from regions showing different micro-mucosal patterns. Associations among the extent of CAFG, micro-mucosal pattern, and histology were examined. As the extent of CAFG increased, the proportion of white villiform type mucosa increased, whereas that of groove type mucosa decreased (P=0.022). In patients with extensive CAFG, most of the areae gastricae was composed of the segmental or central type of white villiform type mucosa (P=0.044). The white villiform type mucosa had significantly higher grades of atrophy (P=0.002) and intestinal metaplasia (P<0.001) than did the groove type mucosa. White villiform type mucosa is indicative of atrophy and intestinal metaplasia in the gastric antrum. It extends to the whole or central part of the areae gastricae as CAFG becomes more extensive.

TRANSP-based Trajectory Optimization of the Current Profile Evolution to Facilitate Robust Non-inductive Ramp-up in NSTX-U

NASA Astrophysics Data System (ADS)

Wehner, William; Schuster, Eugenio; Poli, Francesca

2016-10-01

Initial progress towards the design of non-inductive current ramp-up scenarios in the National Spherical Torus Experiment Upgrade (NSTX-U) has been made through the use of TRANSP predictive simulations. The strategy involves, first, ramping the plasma current with high harmonic fast waves (HHFW) to about 400 kA, and then further ramping to 900 kA with neutral beam injection (NBI). However, the early ramping of neutral beams and application of HHFW leads to an undesirably peaked current profile making the plasma unstable to ballooning modes. We present an optimization-based control approach to improve on the non-inductive ramp-up strategy. We combine the TRANSP code with an optimization algorithm based on sequential quadratic programming to search for time evolutions of the NBI powers, the HHFW powers, and the line averaged density that define an open-loop actuator strategy that maximizes the non-inductive current while satisfying constraints associated with the current profile evolution for MHD stable plasmas. This technique has the potential of playing a critical role in achieving robustly stable non-inductive ramp-up, which will ultimately be necessary to demonstrate applicability of the spherical torus concept to larger devices without sufficient room for a central coil. Supported by the US DOE under the SCGSR Program.

Identification of early cancerous lesion of esophagus with endoscopic images by hyperspectral image technique (Conference Presentation)

NASA Astrophysics Data System (ADS)

Huang, Shih-Wei; Chen, Shih-Hua; Chen, Weichung; Wu, I.-Chen; Wu, Ming Tsang; Kuo, Chie-Tong; Wang, Hsiang-Chen

2016-03-01

This study presents a method to identify early esophageal cancer within endoscope using hyperspectral imaging technology. The research samples are three kinds of endoscopic images including white light endoscopic, chromoendoscopic, and narrow-band endoscopic images with different stages of pathological changes (normal, dysplasia, dysplasia - esophageal cancer, and esophageal cancer). Research is divided into two parts: first, we analysis the reflectance spectra of endoscopic images with different stages to know the spectral responses by pathological changes. Second, we identified early cancerous lesion of esophagus by principal component analysis (PCA) of the reflectance spectra of endoscopic images. The results of this study show that the identification of early cancerous lesion is possible achieve from three kinds of images. In which the spectral characteristics of NBI endoscopy images of a gray area than those without the existence of the problem the first two, and the trend is very clear. Therefore, if simply to reflect differences in the degree of spectral identification, chromoendoscopic images are suitable samples. The best identification of early esophageal cancer is using the NBI endoscopic images. Based on the results, the use of hyperspectral imaging technology in the early endoscopic esophageal cancer lesion image recognition helps clinicians quickly diagnose. We hope for the future to have a relatively large amount of endoscopic image by establishing a hyperspectral imaging database system developed in this study, so the clinician can take this repository more efficiently preliminary diagnosis.

U. S. Army Operation Enduring Freedom Deployment Injury Surveillance Summary, 1 January-31 December 2012

DTIC Science & Technology

2015-06-01

Training, American Football , and Weight Lifting) ......................... 27 8. Causes of Air Evacuated Back Injuries (NBI) Iraq and Afghanistan...American football (14 percent). (Note: These data examples are not shown in the figure.) OEF Injury Intention 1 Air Evacuations...Blood Vessel Contu- sion/Su- perficial Crush Burns Nerves Unspeci- fied System- wide & late effects Post- Concussive Total Percent Percent by Body

Sex differences in corticotropin-releasing factor receptor-1 action within the dorsal raphe nucleus in stress responsivity.

PubMed

Howerton, Alexis R; Roland, Alison V; Fluharty, Jessica M; Marshall, Anikò; Chen, Alon; Daniels, Derek; Beck, Sheryl G; Bale, Tracy L

2014-06-01

Women are twice as likely as men to suffer from stress-related affective disorders. Corticotropin-releasing factor (CRF) is an important link between stress and mood, in part through its signaling in the serotonergic dorsal raphe (DR). Development of CRF receptor-1 (CRFr1) antagonists has been a focus of numerous clinical trials but has not yet been proven efficacious. We hypothesized that sex differences in CRFr1 modulation of DR circuits might be key determinants in predicting therapeutic responses and affective disorder vulnerability. Male and female mice received DR infusions of the CRFr1 antagonist, NBI 35965, or CRF and were evaluated for stress responsivity. Sex differences in indices of neural activation (cFos) and colocalization of CRFr1 throughout the DR were examined. Whole-cell patch-clamp electrophysiology assessed sex differences in serotonin neuron membrane characteristics and responsivity to CRF. Males showed robust behavioral and hypothalamic-pituitary-adrenal axis responses to DR infusion of NBI 35965 and CRF, whereas females were minimally responsive. Sex differences were also found for both CRF-induced DR cFos and CRFr1 co-localization throughout the DR. Electrophysiologically, female serotonergic neurons showed blunted membrane excitability and divergent inhibitory postsynaptic current responses to CRF application. These studies demonstrate convincing sex differences in CRFr1 activity in the DR, where blunted female responses to NBI 35965 and CRF suggest unique stress modulation of the DR. These sex differences might underlie affective disorder vulnerability and differential sensitivity to pharmacologic treatments developed to target the CRF system, thereby contributing to a current lack of CRFr1 antagonist efficacy in clinical trials. © 2013 Published by Society of Biological Psychiatry on behalf of Society of Biological Psychiatry.

Using typical endoscopic features to diagnose esophageal squamous papilloma.

PubMed

Wong, Ming-Wun; Bair, Ming-Joug; Shih, Shou-Chuan; Chu, Cheng-Hsin; Wang, Horng-Yuan; Wang, Tsang-En; Chang, Chen-Wang; Chen, Ming-Jen

2016-02-21

To better understand some of the superficial tiny lesions that are recognized as squamous papilloma of the esophagus (SPE) and receive a different pathological diagnosis. All consecutive patients with esophageal polypoid lesions detected by routine endoscopy at our Endoscopy Centre between October 2009 and June 2014 were retrospectively analysed. We enrolled patients with SPE or other superficial lesions to investigate four key endoscopic appearances (whitish color, exophytic growth, wart-like shape, and surface vessels) and used narrow band imaging (NBI) to distinguish their differences. These series endoscopic images of each patient were retrospectively reviewed by three experienced endoscopists with no prior access to the images. All lesion specimens obtained by forceps biopsy were fixed in formalin and processed for pathological examination. The following data were collected from patient medical records: gender, age, indications for esophagogastroduodenoscopy, and endoscopic characteristics including lesion location, number, color, size, surface morphology, surrounding mucosa, and surface vessels under NBI. Clinicopathological features were also compared. During the study period, 41 esophageal polypoid lesions from 5698 endoscopic examinations were identified retrospectively. These included 24 patients with pathologically confirmed SPE, 11 patients with squamous hyperplasia, three patients with glycogenic acanthosis, two patients with ectopic sebaceous glands, and one patient with a xanthoma. In the χ (2) test, exophytic growth (P = 0.003), a wart-like shape (P < 0.001), and crossing surface vessels under NBI (P = 0.001) were more frequently observed in SPE than in other lesion types. By contrast, there was no significant difference regarding the appearance of a whitish color between SPE and other lesion types (P = 0.872). The most sensitive characteristic was wart-like projections (81.3%) and the most specific was exophytic growth (87.5%). Promising positive predictive values of 84.2%, 80.8%, and 82.6% were noted for exophytic growth, wart-like projections, and surface vessel crossing on NBI, respectively. The use of three key typical endoscopic appearances--exophytic growth, a wart-like shape, and vessel crossing on the lesion surface under NBI--has a promising positive predictive value of 88.2%. This diagnostic triad is useful for the endoscopic diagnosis of SPE.

Using typical endoscopic features to diagnose esophageal squamous papilloma

PubMed Central

Wong, Ming-Wun; Bair, Ming-Joug; Shih, Shou-Chuan; Chu, Cheng-Hsin; Wang, Horng-Yuan; Wang, Tsang-En; Chang, Chen-Wang; Chen, Ming-Jen

2016-01-01

AIM: To better understand some of the superficial tiny lesions that are recognized as squamous papilloma of the esophagus (SPE) and receive a different pathological diagnosis. METHODS: All consecutive patients with esophageal polypoid lesions detected by routine endoscopy at our Endoscopy Centre between October 2009 and June 2014 were retrospectively analysed. We enrolled patients with SPE or other superficial lesions to investigate four key endoscopic appearances (whitish color, exophytic growth, wart-like shape, and surface vessels) and used narrow band imaging (NBI) to distinguish their differences. These series endoscopic images of each patient were retrospectively reviewed by three experienced endoscopists with no prior access to the images. All lesion specimens obtained by forceps biopsy were fixed in formalin and processed for pathological examination. The following data were collected from patient medical records: gender, age, indications for esophagogastroduodenoscopy, and endoscopic characteristics including lesion location, number, color, size, surface morphology, surrounding mucosa, and surface vessels under NBI. Clinicopathological features were also compared. RESULTS: During the study period, 41 esophageal polypoid lesions from 5698 endoscopic examinations were identified retrospectively. These included 24 patients with pathologically confirmed SPE, 11 patients with squamous hyperplasia, three patients with glycogenic acanthosis, two patients with ectopic sebaceous glands, and one patient with a xanthoma. In the χ2 test, exophytic growth (P = 0.003), a wart-like shape (P < 0.001), and crossing surface vessels under NBI (P = 0.001) were more frequently observed in SPE than in other lesion types. By contrast, there was no significant difference regarding the appearance of a whitish color between SPE and other lesion types (P = 0.872). The most sensitive characteristic was wart-like projections (81.3%) and the most specific was exophytic growth (87.5%). Promising positive predictive values of 84.2%, 80.8%, and 82.6% were noted for exophytic growth, wart-like projections, and surface vessel crossing on NBI, respectively. CONCLUSION: The use of three key typical endoscopic appearances - exophytic growth, a wart-like shape, and vessel crossing on the lesion surface under NBI - has a promising positive predictive value of 88.2%. This diagnostic triad is useful for the endoscopic diagnosis of SPE. PMID:26900297

Clinical impact of surveillance for head and neck cancer in patients with esophageal squamous cell carcinoma.

PubMed

Morimoto, Hiroyuki; Yano, Tomonori; Yoda, Yusuke; Oono, Yasuhiro; Ikematsu, Hiroaki; Hayashi, Ryuichi; Ohtsu, Atsushi; Kaneko, Kazuhiro

2017-02-14

To evaluate the clinical impact of surveillance for head and neck (HN) region with narrow band imaging (NBI) in patients with esophageal squamous cell carcinoma (ESCC). Since 2006, we introduced the surveillance for HN region using NBI for all patients with ESCC before treatment, and each follow-up. The patients with newly diagnosed stage I to III ESCC were enrolled and classified into two groups as follows: Group A (no surveillance for HN region); between 1992 and 2000), and Group B (surveillance for HN region with NBI; between 2006 and 2008). We comparatively evaluated the detection rate of superficial head and neck squamous cell carcinoma (HNSCC), and the serious events due to metachronous advanced HNSCC during the follow-up. A total 561 patients (group A: 254, group B: 307) were enrolled. Synchronous superficial HNSCC was detected in 1 patient (0.3%) in group A, and in 12 (3.9%) in group B ( P = 0.008). During the follow up period, metachronous HNSCC were detected in 10 patients (3.9%) in group A and in 30 patients (9.8%) in group B ( P = 0.008). All metachronous lesions in group B were early stage, and 26 patients underwent local resection, however, 6 of 10 patients (60%) in group A lost their laryngeal function and died with metachronous HNSCC. Surveillance for the HN region by using NBI endoscopy increase the detection rate of early HNSCC in patients with ESCC, and led to decrease serious events related to advanced metachronous HNSCC.

Transport studies in high-performance field reversed configuration plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, S., E-mail: sgupta@trialphaenergy.com; Barnes, D. C.; Dettrick, S. A.

2016-05-15

A significant improvement of field reversed configuration (FRC) lifetime and plasma confinement times in the C-2 plasma, called High Performance FRC regime, has been observed with neutral beam injection (NBI), improved edge stability, and better wall conditioning [Binderbauer et al., Phys. Plasmas 22, 056110 (2015)]. A Quasi-1D (Q1D) fluid transport code has been developed and employed to carry out transport analysis of such C-2 plasma conditions. The Q1D code is coupled to a Monte-Carlo code to incorporate the effect of fast ions, due to NBI, on the background FRC plasma. Numerically, the Q1D transport behavior with enhanced transport coefficients (butmore » with otherwise classical parametric dependencies) such as 5 times classical resistive diffusion, classical thermal ion conductivity, 20 times classical electron thermal conductivity, and classical fast ion behavior fit with the experimentally measured time evolution of the excluded flux radius, line-integrated density, and electron/ion temperature. The numerical study shows near sustainment of poloidal flux for nearly 1 ms in the presence of NBI.« less

Neuropsychological and neurophysiological benefits from white noise in children with and without ADHD.

PubMed

Baijot, Simon; Slama, Hichem; Söderlund, Göran; Dan, Bernard; Deltenre, Paul; Colin, Cécile; Deconinck, Nicolas

2016-03-15

Optimal stimulation theory and moderate brain arousal (MBA) model hypothesize that extra-task stimulation (e.g. white noise) could improve cognitive functions of children with attention-deficit/hyperactivity disorder (ADHD). We investigate benefits of white noise on attention and inhibition in children with and without ADHD (7-12 years old), both at behavioral and at neurophysiological levels. Thirty children with and without ADHD performed a visual cued Go/Nogo task in two conditions (white noise or no-noise exposure), in which behavioral and P300 (mean amplitudes) data were analyzed. Spontaneous eye-blink rates were also recorded and participants went through neuropsychological assessment. Two separate analyses were conducted with each child separately assigned into two groups (1) ADHD or typically developing children (TDC), and (2) noise beneficiaries or non-beneficiaries according to the observed performance during the experiment. This latest categorization, based on a new index we called "Noise Benefits Index" (NBI), was proposed to determine a neuropsychological profile positively sensitive to noise. Noise exposure reduced omission rate in children with ADHD, who were no longer different from TDC. Eye-blink rate was higher in children with ADHD but was not modulated by white noise. NBI indicated a significant relationship between ADHD and noise benefit. Strong correlations were observed between noise benefit and neuropsychological weaknesses in vigilance and inhibition. Participants who benefited from noise had an increased Go P300 in the noise condition. The improvement of children with ADHD with white noise supports both optimal stimulation theory and MBA model. However, eye-blink rate results question the dopaminergic hypothesis in the latter. The NBI evidenced a profile positively sensitive to noise, related with ADHD, and associated with weaker cognitive control.

Preliminary experience with 4K ultra-high definition endoscope: analysis of pros and cons in skull base surgery.

PubMed

Rigante, M; La Rocca, G; Lauretti, L; D'Alessandris, G Q; Mangiola, A; Anile, C; Olivi, A; Paludetti, G

2017-06-01

During the last two decades endoscopic skull base surgery observed a continuous technical and technological development 3D endoscopy and ultra High Definition (HD) endoscopy have provided great advances in terms of visualisation and spatial resolution. Ultra-high definition (UHD) 4K systems, recently introduced in the clinical practice, will shape next steps forward especially in skull base surgery field. Patients were operated on through transnasal transsphenoidal endoscopic approaches performed using Olympus NBI 4K UHD endoscope with a 4 mm 0° Ultra Telescope, 300 W xenon lamp (CLV-S400) predisposed for narrow band imaging (NBI) technology connected through a camera head to a high-quality control unit (OTV-S400 - VISERA 4K UHD) (Olympus Corporation, Tokyo, Japan). Two screens are used, one 31" Monitor - (LMD-X310S) and one main ultra-HD 55" screen optimised for UHD image reproduction (LMD-X550S). In selected cases, we used a navigation system (Stealthstation S7, Medtronic, Minneapolis, MN, US). We evaluated 22 pituitary adenomas (86.3% macroadenomas; 13.7% microadenomas). 50% were not functional (NF), 22.8% GH, 18.2% ACTH, 9% PRL-secreting. Three of 22 were recurrences. In 91% of cases we achieved total removal, while in 9% near total resection. A mean follow-up of 187 days and average length of hospitalisation was 3.09 ± 0.61 days. Surgical duration was 128.18± 30.74 minutes. We experienced only 1 case of intraoperative low flow fistula with no further complications. None of the cases required any post- or intraoperative blood transfusion. The visualisation and high resolution of the operative field provided a very detailed view of all anatomical structures and pathologies allowing an improvement in safety and efficacy of the surgical procedure. The operative time was similar to the standard 2D HD and 3D procedures and the physical strain was also comparable to others in terms of ergonomics and weight. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Faraday-cup-type lost fast ion detector on Heliotron J.

PubMed

Yamamoto, S; Ogawa, K; Isobe, M; Darrow, D S; Kobayashi, S; Nagasaki, K; Okada, H; Minami, T; Kado, S; Ohshima, S; Weir, G M; Nakamura, Y; Konoshima, S; Kemmochi, N; Ohtani, Y; Mizuuchi, T

2016-11-01

A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7-42.5 keV (proton) and pitch angle of 90 ∘ -140 ∘ , especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamamoto, S., E-mail: yamamoto.satoshi.6n@kyoto-u.ac.jp; Kobayashi, S.; Nagasaki, K.

A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7–42.5 keV (proton) and pitch angle of 90{sup ∘}–140{sup ∘}, especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

Review of particle-in-cell modeling for the extraction region of large negative hydrogen ion sources for fusion

NASA Astrophysics Data System (ADS)

Wünderlich, D.; Mochalskyy, S.; Montellano, I. M.; Revel, A.

2018-05-01

Particle-in-cell (PIC) codes are used since the early 1960s for calculating self-consistently the motion of charged particles in plasmas, taking into account external electric and magnetic fields as well as the fields created by the particles itself. Due to the used very small time steps (in the order of the inverse plasma frequency) and mesh size, the computational requirements can be very high and they drastically increase with increasing plasma density and size of the calculation domain. Thus, usually small computational domains and/or reduced dimensionality are used. In the last years, the available central processing unit (CPU) power strongly increased. Together with a massive parallelization of the codes, it is now possible to describe in 3D the extraction of charged particles from a plasma, using calculation domains with an edge length of several centimeters, consisting of one extraction aperture, the plasma in direct vicinity of the aperture, and a part of the extraction system. Large negative hydrogen or deuterium ion sources are essential parts of the neutral beam injection (NBI) system in future fusion devices like the international fusion experiment ITER and the demonstration reactor (DEMO). For ITER NBI RF driven sources with a source area of 0.9 × 1.9 m2 and 1280 extraction apertures will be used. The extraction of negative ions is accompanied by the co-extraction of electrons which are deflected onto an electron dump. Typically, the maximum negative extracted ion current is limited by the amount and the temporal instability of the co-extracted electrons, especially for operation in deuterium. Different PIC codes are available for the extraction region of large driven negative ion sources for fusion. Additionally, some effort is ongoing in developing codes that describe in a simplified manner (coarser mesh or reduced dimensionality) the plasma of the whole ion source. The presentation first gives a brief overview of the current status of the ion source development for ITER NBI and of the PIC method. Different PIC codes for the extraction region are introduced as well as the coupling to codes describing the whole source (PIC codes or fluid codes). Presented and discussed are different physical and numerical aspects of applying PIC codes to negative hydrogen ion sources for fusion as well as selected code results. The main focus of future calculations will be the meniscus formation and identifying measures for reducing the co-extracted electrons, in particular for deuterium operation. The recent results of the 3D PIC code ONIX (calculation domain: one extraction aperture and its vicinity) for the ITER prototype source (1/8 size of the ITER NBI source) are presented.

Conceptual design of the beam source for the DEMO Neutral Beam Injectors

NASA Astrophysics Data System (ADS)

Sonato, P.; Agostinetti, P.; Fantz, U.; Franke, T.; Furno, I.; Simonin, A.; Tran, M. Q.

2016-12-01

DEMO (DEMOnstration Fusion Power Plant) is a proposed nuclear fusion power plant that is intended to follow the ITER experimental reactor. The main goal of DEMO will be to demonstrate the possibility to produce electric energy from the fusion reaction. The injection of high energy neutral beams is one of the main tools to heat the plasma up to fusion conditions. A conceptual design of the Neutral Beam Injector (NBI) for the DEMO fusion reactor, is currently being developed by Consorzio RFX in collaboration with other European research institutes. High efficiency and low recirculating power, which are fundamental requirements for the success of DEMO, have been taken into special consideration for the DEMO NBI. Moreover, particular attention has been paid to the issues related to reliability, availability, maintainability and inspectability. A conceptual design of the beam source for the DEMO NBI is here presented featuring 20 sub-sources (two adjacent columns of 10 sub-sources each), following a modular design concept, with each sub-source featuring its radio frequency driver, capable of increasing the reliability and availability of the DEMO NBI. Copper grids with increasing size of the apertures have been adopted in the accelerator, with three main layouts of the apertures (circular apertures, slotted apertures and frame-like apertures for each sub-source). This design, permitting to significantly decrease the stripping losses in the accelerator without spoiling the beam optics, has been investigated with a self-consistent model able to study at the same time the magnetic field, the electrostatic field and the trajectory of the negative ions. Moreover, the status on the R&D carried out in Europe on the ion sources is presented.

Liver stiffness measurement, better than APRI, Fibroindex, Fib-4, and NBI gastroscopy, predicts portal hypertension in patients with cirrhosis.

PubMed

Zhang, Wei; Wang, Liqiong; Wang, Lei; Li, Gang; Huang, Aoshuang; Yin, Ping; Yang, Zhenhua; Ling, Changquan; Wang, Lingtai

2015-03-01

Liver stiffness measurement (LSM) is frequently used as non-invasive alternative for liver fibrosis including cirrhosis, which can lead to portal hypertension. This study was conducted to evaluate the predictive value of LSM in cirrhosis-induced portal hypertension patients. Between July 2011 and December 2013, 153 participants were enrolled into a single-center, prospective, cross-sectional study. Each subject received both gastroscopy and LSM. Baseline biochemical, APRI, Fibroindex, and Fib-4 were also performed. LSM of cirrhosis patients with portal hypertension was significantly higher compared to those without portal hypertension (P < 0.05). A LSM ≥ 13.6 kPa had a sensitivity of 83.87 % and a specificity of 72.53 % with an accuracy of 77.1 for the prediction of portal hypertension, which are higher than those of APRI, Fib-4, and Fibroscan separately. A combination of Fibroscan combined with Fib-4 achieved a maximum AUC of 0.833 and accuracy of 77.8. Discriminant and internal validation analysis showed that Fibroscan plus APRI obtained a lower false negative rate compared to Fibroscan plus Fib-4 and Fibroscan plus Fibroindex (9.68, 17.74, and 11.29 %, respectively). A good relationship was found between LSM and NBI mean optical density both by linear and polynomial correlation analysis (r = 0.5533 and r = 0.7349, both P < 0.001). There was a trend toward a better performance of LSM for assessing portal hypertension compared with NBI gastroscopy mean optical density (P = 0.028 and P = 0.05, respectively). Better than APRI, Fibroindex, Fib-4, and NBI gastroscopy, LSM can predict portal hypertension in cirrhosis patients. A LSM of 13.6 kPa can be considered to be the predictive value for portal hypertension.

A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

NASA Astrophysics Data System (ADS)

Pilan, N.; Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E.

2016-02-01

A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices.

PubMed

Pilan, N; Antoni, V; De Lorenzi, A; Chitarin, G; Veltri, P; Sartori, E

2016-02-01

A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

Helicon wave-generated plasmas for negative ion beams for fusion

NASA Astrophysics Data System (ADS)

Furno, Ivo; Agnello, Riccardo; Fantz, U.; Howling, Alan; Jacquier, Remy; Marini, Claudio; Plyushchev, Gennady; Guittienne, Philippe; Simonin, Alain

2017-10-01

In the next generation of fusion reactors, such as DEMO, neutral beam injectors (NBIs) of high energy (0.8-1 MeV) deuterium atoms with high wall-plug efficiency (>50%) will be required to reach burning plasma conditions and to provide a significant amount of current drive. The present NBI system for DEMO assumes that 50 MW is delivered to the plasma by 3 NBIs. In the Siphore NBI concept, negative deuterium ions are extracted from a long, thin ion source 3 m high and 15 cm wide, accelerated and subsequently photo-neutralized. This requires the development of a new generation of negative ion sources. At the Swiss Plasma Center, a novel radio frequency helicon plasma source, based on a resonant network antenna source delivering up to 10 kW at 13.56 MHz, has been developed and is presently under study on the Resonant Antenna Ion Device (RAID). RAID is a linear device (1.9 m total length, 0.4 m diameter) and is equipped with an extensive set of diagnostics for full plasma characterization. In this work, the principles of operation of resonant antennas as helicon sources are introduced. We present absolute spectroscopy, Langmuir probe, and interferometry measurements on helicon plasmas. We characterize the performance of the source in terms of hydrogen/deuterium dissociation and negative ion production as a function of the input power. Furthermore, first results with the helicon birdcage antenna installed on the Cybele negative ion source at CEA-IRFM are presented, as a first step towards the validation of the Siphore concept.

EDITORIAL: Special section on recent progress on radio frequency heating and current drive studies in the JET tokamak Special section on recent progress on radio frequency heating and current drive studies in the JET tokamak

NASA Astrophysics Data System (ADS)

Ongena, Jef; Mailloux, Joelle; Mayoral, Marie-Line

2009-04-01

This special cluster of papers summarizes the work accomplished during the last three years in the framework of the Task Force Heating at JET, whose mission it is to study the optimisation of heating systems for plasma heating and current drive, launching and deposition questions and the physics of plasma rotation. Good progress and new physics insights have been obtained with the three heating systems available at JET: lower hybrid (LH), ion cyclotron resonance heating (ICRH) and neutral beam injection (NBI). Topics covered in the present issue are the use of edge gas puffing to improve the coupling of LH waves at large distances between the plasma separatrix and the LH launcher. Closely linked with this topic are detailed studies of the changes in LH coupling due to modifications in the scrape-off layer during gas puffing and simultaneous application of ICRH. We revisit the fundamental ICRH heating of D plasmas, include new physics results made possible by recently installed new diagnostic capabilities on JET and point out caveats for ITER when NBI is simultaneously applied. Other topics are the study of the anomalous behaviour of fast ions from NBI, and a study of toroidal rotation induced by ICRH, both again with possible implications for ITER. In finalizing this cluster of articles, thanks are due to all colleagues involved in preparing and executing the JET programme under EFDA in recent years. We want to thank the EFDA leadership for the special privilege of appointing us as Leaders or Deputies of Task Force Heating, a wonderful and hardworking group of colleagues. Thanks also to all other European and non-European scientists who contributed to the JET scientific programme, the Operations team of JET and the colleagues of the Close Support Unit (CSU). Thanks are also due to the Editors, Editorial Board and referees of Plasma Physics and Controlled Fusion together with the publishing staff of IOP Publishing who have supported and contributed substantially to this initiative.

Active core profile and transport modification by application of ion Bernstein wave power in the Princeton Beta Experiment-Modification

NASA Astrophysics Data System (ADS)

LeBlanc, B.; Batha, S.; Bell, R.; Bernabei, S.; Blush, L.; de la Luna, E.; Doerner, R.; Dunlap, J.; England, A.; Garcia, I.; Ignat, D.; Isler, R.; Jones, S.; Kaita, R.; Kaye, S.; Kugel, H.; Levinton, F.; Luckhardt, S.; Mutoh, T.; Okabayashi, M.; Ono, M.; Paoletti, F.; Paul, S.; Petravich, G.; Post-Zwicker, A.; Sauthoff, N.; Schmitz, L.; Sesnic, S.; Takahashi, H.; Talvard, M.; Tighe, W.; Tynan, G.; von Goeler, S.; Woskov, P.; Zolfaghari, A.

1995-03-01

Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH-assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large ∇ne, ∇Te, ∇νφ, and ∇Ti, delimiting the confinement zone. This regime is reminiscent of the H(high) mode, but with a confinement zone moved inward. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhances NBI core deposition and increases nuclear reactivity. An increase in central Ti results from χi reduction (compared to the H mode) and better beam penetration. Bootstrap current fractions of up to 0.32-0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma.

Modelling of combined ICRF and NBI heating in JET hybrid plasmas

NASA Astrophysics Data System (ADS)

Gallart, Dani; Mantsinen, Mervi; Challis, Clive; Frigione, Domenico; Graves, Jonathan; Hobirk, Joerg; Belonohy, Eva; Czarnecka, Agata; Eriksson, Jacob; Goniche, Marc; Hellesen, Carl; Jacquet, Philippe; Joffrin, Emmanuel; Krawczyk, Natalia; King, Damian; Lennholm, Morten; Lerche, Ernesto; Pawelec, Ewa; Sips, George; Solano, Emilia; Tsalas, Maximos; Valisa, Marco

2017-10-01

During the 2015-2016 JET campaigns many efforts have been devoted to the exploration of high performance plasma scenarios envisaged for ITER operation. In this paper we model the combined ICRF+NBI heating in selected key hybrid discharges using PION. The antenna frequency was tuned to match the cyclotron frequency of minority hydrogen (H) at the center of the tokamak coinciding with the second harmonic cyclotron resonance of deuterium. The modelling takes into account the synergy between ICRF and NBI heating through the second harmonic cyclotron resonance of deuterium beam ions which allows us to assess its impact on the neutron rate RNT. We evaluate the influence of H concentration which was varied in different discharges in order to test their role in the heating performance. According to our modelling, the ICRF enhancement of RNT increases by decreasing the H concentration which increases the ICRF power absorbed by deuterons. We find that in the recent hybrid discharges this ICRF enhancement was in the range of 10-25%. Finally, we extrapolate the results to D-T and find that the best performing hybrid discharges correspond to an equivalent fusion power of ˜7.0 MW in D-T.

High specification starter diets improve the performance of low birth weight pigs to 10 weeks of age.

PubMed

Douglas, S L; Wellock, I; Edwards, S A; Kyriazakis, I

2014-10-01

Piglets born with low birth weights (LBiW) are likely to be lighter at weaning. Starter regimes tailored for pigs of average BW therefore may not be optimal for LBiW nursery performance. The objective was to determine if LBiW pigs benefit from a high specification starter regime and the provision of extra feed (additional allowance of last phase diet of the starter regime) in comparison to a standard commercial regime. Additionally, the effect of starter regime on performance of normal birth weight (NBiW) pigs at weaning was determined and compared to that of LBiW pigs. Finally, the cost effectiveness of the treatments was determined. The experiment was therefore an incomplete 2 × 2 × 2 factorial design, as the provision of extra feed was given only to LBiW pigs (n = 6 replicates per treatment; 5 pigs per replicate). Treatments comprised birth weight (LBiW or NBiW), starter regime (high specification [HS] or standard starter [SS]), and extra feed 3 quantity (yes [YF] or no [NF], for LBiW pigs only; feed 3 corresponded to the last phase diet of the starter regime). At weaning (d 28), pigs were randomly assigned within each birth weight category to treatment groups. Nutritional treatments were fed ad libitum on a kilogram/head basis for approximately 3 wk followed by a common weaner diet fed ad libitum until d 70. Starter regime (P = 0.019), feed 3 amount (P = 0.010), and their interaction (P = 0.029) had an effect on ADG of LBiW pigs from d 28 to 49, with pigs on HS followed by YF (HY) performing best. An improvement in feed conversion ratio (FCR) was noted between d 28 and 49 for pigs fed the additional feed 3 (P = 0.030); between d 49 and 70, the only residual effect seen was of starter regime (P = 0.017) on ADG. In contrast, there was no significant effect of starter regime from d 28 to 70 on ADG, ADFI, or FCR of NBiW pigs. By d 49 and 70, LBiW pigs on regime HY weighed the same as NBiW pigs (d 70 BW; 30.0 vs. 30.6 kg; P = 0.413), with similar growth rates from d 28 to 70 (0.570 vs. 0.533 kg/d; P = 0.137). Despite highest feed cost for regime HY at US$12.30 per pig, its margin over feed was greatest ($23.40). Conversely, regime SS gave the best margin over feed for NBiW pigs at $22.70 per pig. In conclusion, a postweaning feeding regime formulated for LBiW pigs improved the ADG and FCR to the end of the nursery phase enabling them to achieve the same weight as NBiW. Targeting the provision of the high quality expensive regime only to light pigs will ensure maximum growth and increased profitability.

Equilibrium and Stability Properties of Low Aspect Ratio Mirror Systems: from Neutron Source Design to the Parker Spiral

NASA Astrophysics Data System (ADS)

Peterson, Ethan; Anderson, Jay; Clark, Mike; Egedal, Jan; Endrizzi, Douglass; Flanagan, Ken; Harvey, Robert; Lynn, Jacob; Milhone, Jason; Wallace, John; Waleffe, Roger; Mirnov, Vladimir; Forest, Cary

2017-10-01

Equilibrium reconstructions of rotating magnetospheres in the lab are computed using a user-friendly extended Grad-Shafranov solver written in Python and various magnetic and kinetic measurements. The stability of these equilibria are investigated using the NIMROD code with two goals: understand the onset of the classic ``wobble'' in the heliospheric current sheet and demonstrating proof-of-principle for a laboratory source of high- β turbulence. Using the same extended Grad-Shafranov solver, equilibria for an axisymmetric, non-paraxial magnetic mirror are used as a design foundation for a high-field magnetic mirror neutron source. These equilibria are numerically shown to be stable to the m=1 flute instability, with higher modes likely stabilized by FLR effects; this provides stability to gross MHD modes in an axisymmetric configuration. Numerical results of RF heating and neutral beam injection (NBI) from the GENRAY/CQL3D code suite show neutron fluxes promising for medical radioisotope production as well as materials testing. Synergistic effects between NBI and high-harmonic fast wave heating show large increases in neutron yield for a modest increase in RF power. work funded by DOE, NSF, NASA.

Modelling of caesium dynamics in the negative ion sources at BATMAN and ELISE

NASA Astrophysics Data System (ADS)

Mimo, A.; Wimmer, C.; Wünderlich, D.; Fantz, U.

2017-08-01

The knowledge of Cs dynamics in negative hydrogen ion sources is a primary issue to achieve the ITER requirements for the Neutral Beam Injection (NBI) systems, i.e. one hour operation with an accelerated ion current of 40 A of D- and a ratio between negative ions and co-extracted electrons below one. Production of negative ions is mostly achieved by conversion of hydrogen/deuterium atoms on a converter surface, which is caesiated in order to reduce the work function and increase the conversion efficiency. The understanding of the Cs transport and redistribution mechanism inside the source is necessary for the achievement of high performances. Cs dynamics was therefore investigated by means of numerical simulations performed with the Monte Carlo transport code CsFlow3D. Simulations of the prototype source (1/8 of the ITER NBI source size) have shown that the plasma distribution inside the source has the major effect on Cs dynamics during the pulse: asymmetry of the plasma parameters leads to asymmetry in Cs distribution in front of the plasma grid. The simulated time traces and the general simulation results are in agreement with the experimental measurements. Simulations performed for the ELISE testbed (half of the ITER NBI source size) have shown an effect of the vacuum phase time on the amount and stability of Cs during the pulse. The sputtering of Cs due to back-streaming ions was reproduced by the simulations and it is in agreement with the experimental observation: this can become a critical issue during long pulses, especially in case of continuous extraction as foreseen for ITER. These results and the acquired knowledge of Cs dynamics will be useful to have a better management of Cs and thus to reduce its consumption, in the direction of the demonstration fusion power plant DEMO.

A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilan, N., E-mail: nicola.pilan@igi.cnr.it; Antoni, V.; De Lorenzi, A.

A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BSmore » to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF{sub 6} instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.« less

Observation of Alpha-Driven TAEs in TFTR

NASA Astrophysics Data System (ADS)

Nazikian, R.; Chang, Z.; Fu, G. Y.; Majeski, R.; Batha, S.; Bell, M.; Budny, R.; Cheng, C. Z.; Darrow, D. S.; Duong, H.; Efthimion, P. C.; Fredrickson, E.; Levinton, F.; Mazzucato, E.; Medley, S.; Taylor, S.; Zweben, G.

1996-11-01

Transient mode activity in the TAE range of frequencies (150-170 kHz) with toroidal mode numbers n=2,3 is observed in reduced magnetic shear DT discharges on TFTR with a fusion power threshold of ~1.5 MW. Mode activity appears 50-100 msec after NBI in discharges with the following machine parameter: B=5.3 T, I=1.6MA, R=260cm, P_NBI=25-28 MW, q(0)>2.0 from MSE and toroidal beta β_T<1%. The elevated q(0) and reduced central shear |s|<0.2 is achieved using a full size plasma startup with delayed NBI. Theoretical calculations using NOVA-K indicate that the combined effect of low shear, low beta and elevated q(0) leads to a very low instability threshold for the alpha-driven TAE with β_α (0) ~ 10-4. This appears to be consistent with experimental observations of mode activity in DT plasmas with β_α ~ 10-4 (determined from TRANSP analysis). Thus far the modes have only been observed on Mirnov coils with fluctuation levels tildeB ~ 1mG. Efforts to determine mode location by perturbing the edge density and inducing strong toroidal velocity shear will be reported, as will efforts to affect mode stability by systematically varying the central safety factor.

Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grierson, B. A.; Staebler, G. M.; Solomon, W. M.

Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changesmore » in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. Finally, for a range of E×B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.« less

Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER

DOE PAGES

Grierson, B. A.; Staebler, G. M.; Solomon, W. M.; ...

2018-02-01

Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changesmore » in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. Finally, for a range of E×B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.« less

Multi-scale transport in the DIII-D ITER baseline scenario with direct electron heating and projection to ITER

NASA Astrophysics Data System (ADS)

Grierson, B. A.; Staebler, G. M.; Solomon, W. M.; McKee, G. R.; Holland, C.; Austin, M.; Marinoni, A.; Schmitz, L.; Pinsker, R. I.; DIII-D Team

2018-02-01

Multi-scale fluctuations measured by turbulence diagnostics spanning long and short wavelength spatial scales impact energy confinement and the scale-lengths of plasma kinetic profiles in the DIII-D ITER baseline scenario with direct electron heating. Contrasting discharge phases with ECH + neutral beam injection (NBI) and NBI only at similar rotation reveal higher energy confinement and lower fluctuations when only NBI heating is used. Modeling of the core transport with TGYRO using the TGLF turbulent transport model and NEO neoclassical transport reproduces the experimental profile changes upon application of direct electron heating and indicates that multi-scale transport mechanisms are responsible for changes in the temperature and density profiles. Intermediate and high-k fluctuations appear responsible for the enhanced electron thermal flux, and intermediate-k electron modes produce an inward particle pinch that increases the inverse density scale length. Projection to ITER is performed with TGLF and indicates a density profile that has a finite scale length due to intermediate-k electron modes at low collisionality and increases the fusion gain. For a range of E × B shear, the dominant mechanism that increases fusion performance is suppression of outward low-k particle flux and increased density peaking.

The Electron Bernstein Waves Heating Project In The TJ-II Stellarator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, A.; Cappa, A.; Castejon, F.

2007-09-28

TJ-II is a middle sized flexible Heliac operating in Madrid, whose plasmas are created and heated by ECRH via two 300 kW gyrotrons at second harmonic X-mode (53.2 GHz). Neutral beam injection is used for second phase heating. Since the cut off density for the 2nd harmonic X-mode (n{sub c} = 1.7x10 {sup 19} m{sup -3}) is reached during NBI, EBWs are considered both for providing additional heating after NBI switch on and to perform kinetic studies in high-density plasmas. Previous work has shown that the most suitable scheme for launching EBWs in TJ-II is O-X-B mode conversion, which hasmore » acceptable heating efficiency for central densities above 1.2x10{sup 19} m{sup -3}, with an operating frequency of 28 GHz. In this work, the most relevant theoretical calculations are presented, including the relativistic effects both in ray trajectory and absorption, as well as the results of the optimization of the beam parameters that provide the maximum O-X conversion efficiency at the critical layer. A system based on a 28 GHz-100 ms diode gyrotron will be used to deliver 300 kW through a corrugated waveguide. The microwave beam is directed and focused by a steerable mirror located inside the vacuum vessel. A diagnostic for measuring the EBW emission has been designed and tested on the bench. It uses a section of corrugated waveguide and a glass lens to focus the emission from the plasma into the aperture of a dual polarized quad-ridged horn. It will allow us to determine the EBW mode conversion efficiency, and also provides an indication of the electron temperature evolution in overdense plasmas.« less

The prevalence of diabetes, hypertension and obesity among immigrants from East Africa and the former Soviet Union: a retrospective comparative 30-year cohort study.

PubMed

Reuven, Yonatan; Dreiher, Jacob; Shvartzman, Pesach

2016-05-05

Previous studies have reported an increasing prevalence of metabolic abnormalities in immigrants who moved from low-cardiovascular-risk regions to Western countries, but little is known about time trends following immigration. A retrospective cohort study of immigrants from Ethiopia in east Africa (EAI), the former Soviet Union (FSUI) and native-born Israelis (NBI) over a 35-year period. EAI were divided into three groups by date of immigration. Associations between ethnicity, age, sex and metabolic risk factors were assessed using logistic regression models. The study included 58,901 individuals (20,768 EAI, 20,507 FSUI, and 17,626 NBI). The multivariate odds ratios (OR) for diabetes were 2.4 (95 % CI 2.1-2.6), 2.1 (95 % CI 1.9-2.2) and 1.5 (95 % CI 1.3-1.7), respectively, for the three waves of EAI immigrations (P < 0.001 for trend) and 1.1 (95 % CI 0.9-1.2) for FSUI. For hypertension, the corresponding ORs were 1.8 (95 % CI 1.6-1.9), 1.4 (95 % CI 1.3-1.5), and 1.1 (95 % CI 0.9-1.2), respectively (P < 0.001) for EAI, and 2.1 (95 % CI 1.9-2.2) for FSUI. For obesity the ORs were -0.5 (95 % CI 0.4-0.6), 0.5 (95 % CI 0.4-0.6), and 0.3 (95 % CI 0.2-0.3), respectively (P < 0.001) for EAI, and 1.2 (95 % CI 1.1-1.3) for FSUI. The prevalence of diabetes in NBI with a BMI of 30 was identical to a BMI of 23.4 for EAI and 28.9 for FSUI. The prevalence of diabetes and hypertension was higher in EAI and increased over the years, despite a lower prevalence of obesity. It exceeded the prevalence rates in NBI.

Non-inductive current drive and transport in high βN plasmas in JET

NASA Astrophysics Data System (ADS)

Voitsekhovitch, I.; Alper, B.; Brix, M.; Budny, R. V.; Buratti, P.; Challis, C. D.; Ferron, J.; Giroud, C.; Joffrin, E.; Laborde, L.; Luce, T. C.; McCune, D.; Menard, J.; Murakami, M.; Park, J. M.; JET-EFDA contributors

2009-05-01

A route to stationary MHD stable operation at high βN has been explored at the Joint European Torus (JET) by optimizing the current ramp-up, heating start time and the waveform of neutral beam injection (NBI) power. In these scenarios the current ramp-up has been accompanied by plasma pre-heat (or the NBI has been started before the current flat-top) and NBI power up to 22 MW has been applied during the current flat-top. In the discharges considered transient total βN ≈ 3.3 and stationary (during high power phase) βN ≈ 3 have been achieved by applying the feedback control of βN with the NBI power in configurations with monotonic or flat core safety factor profile and without an internal transport barrier (ITB). The transport and current drive in this scenario is analysed here by using the TRANSP and ASTRA codes. The interpretative analysis performed with TRANSP shows that 50-70% of current is driven non-inductively; half of this current is due to the bootstrap current which has a broad profile since an ITB was deliberately avoided. The GLF23 transport model predicts the temperature profiles within a ±22% discrepancy with the measurements over the explored parameter space. Predictive simulations with this model show that the E × B rotational shear plays an important role for thermal ion transport in this scenario, producing up to a 40% increase of the ion temperature. By applying transport and current drive models validated in self-consistent simulations of given reference scenarios in a wider parameter space, the requirements for fully non-inductive stationary operation at JET are estimated. It is shown that the strong stiffness of the temperature profiles predicted by the GLF23 model restricts the bootstrap current at larger heating power. In this situation full non-inductive operation without an ITB can be rather expensive strongly relying on the external non-inductive current drive sources.

Synthesis and characterization study of n-Bi2O3/p-Si heterojunction dependence on thickness

NASA Astrophysics Data System (ADS)

Al-Maiyaly, Bushra K. H.; Hussein, Bushra H.; Salih, Ayad A.; Shaban, Auday H.; Mahdi, Shatha H.; Khudayer, Iman H.

2018-05-01

In this work, Bi2O3 was deposited as a thin film of different thickness (400, 500, and 600 ±20 nm) by using thermal oxidation at 573 K with ambient oxygen of evaporated bismuth (Bi) thin films in a vacuum on glass substrate and on Si wafer to produce n-Bi2O3/p-Si heterojunction. The effect of thickness on the structural, electrical, surface and optical properties of Bi2O3 thin films was studied. XRD analysis reveals that all the as deposited Bi2O3 films show polycrystalline tetragonal structure, with preferential orientation in the (201) direction, without any change in structure due to increase of film thickness. AFM and SEM images are used to investigate the influences of film thickness on surface properties. The optical measurement were taken for the wave length range (400-1100) nm showed that the nature of the optical transition has been direct allowed with average band gap energies varies in the range of (2.9-2.25) eV with change thickness parameter. The extent and nature of transmittance, absorbance, reflectance and optimized band gap of the material assure to utilize it for photovoltaic applications. Hall measurements showed that all the films are n-type. The electrical properties of n-Bi2O3/p-Si heterojunction (HJ) were obtained by I-V (dark and illuminated) and C-V measurement at frequency (10 MHz) at different thickness. The ideality factor saturation current density, depletion width, built-in potential and carrier concentration are characterized under different thickness. The results show these HJ were of abrupt type. The photovoltaic measurements short-circuit current density, open-circuit voltage, fill factor and efficiencies are determined for all samples. Finally thermal oxidation allowed fabrication n-Bi2O3/p-Si heterojunction with different thickness for solar cell application.

Validation of the kinetic-turbulent-neoclassical theory for edge intrinsic rotation in DIII-D

NASA Astrophysics Data System (ADS)

Ashourvan, Arash; Grierson, B. A.; Battaglia, D. J.; Haskey, S. R.; Stoltzfus-Dueck, T.

2018-05-01

In a recent kinetic model of edge main-ion (deuterium) toroidal velocity, intrinsic rotation results from neoclassical orbits in an inhomogeneous turbulent field [T. Stoltzfus-Dueck, Phys. Rev. Lett. 108, 065002 (2012)]. This model predicts a value for the toroidal velocity that is co-current for a typical inboard X-point plasma at the core-edge boundary (ρ ˜ 0.9). Using this model, the velocity prediction is tested on the DIII-D tokamak for a database of L-mode and H-mode plasmas with nominally low neutral beam torque, including both signs of plasma current. Values for the flux-surface-averaged main-ion rotation velocity in the database are obtained from the impurity carbon rotation by analytically calculating the main-ion—impurity neoclassical offset. The deuterium rotation obtained in this manner has been validated by direct main-ion measurements for a limited number of cases. Key theoretical parameters of ion temperature and turbulent scale length are varied across a wide range in an experimental database of discharges. Using a characteristic electron temperature scale length as a proxy for a turbulent scale length, the predicted main-ion rotation velocity has a general agreement with the experimental measurements for neutral beam injection (NBI) powers in the range PNBI < 4 MW. At higher NBI power, the experimental rotation is observed to saturate and even degrade compared to theory. TRANSP-NUBEAM simulations performed for the database show that for discharges with nominally balanced—but high powered—NBI, the net injected torque through the edge can exceed 1 Nm in the counter-current direction. The theory model has been extended to compute the rotation degradation from this counter-current NBI torque by solving a reduced momentum evolution equation for the edge and found the revised velocity prediction to be in agreement with experiment. Using the theory modeled—and now tested—velocity to predict the bulk plasma rotation opens up a path to more confidently projecting the confinement and stability in ITER.

Maintenance method and its critical issues for a fast-ignition laser fusion reactor based on a dry wall chamber

NASA Astrophysics Data System (ADS)

Someya, Y.; Matsumoto, T.; Okano, K.; Asaoka, Y.; Hiwatari, R.; Goto, T.; Ogawa, Y.

2008-05-01

The neutronics analysis has been carried out for feasibility study of the FALCON-D concept by Monte Carlo N-paticle transport code (MCNP), in order to inspect the cooling performance of in-vessel and ex-vessel components, and a connection pipe between Vacuum Vessel and reactor room. The nuclear heating rate in the Vacuum Vessel was at the same level as that of NBI duct of the ITER. The temperature of the connection pipe was found to be 345·, ·which was smaller than the melting point of structure materials (F82H). Moreover, the radiation damage of the final optics was also investigated. We propose a sliding changer concept for replacement. This method could be adapted for the replacement of one FPY cycle in the final optics system.

Steady state plasma operation in RF dominated regimes on EAST

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, X. J.; Zhao, Y. P.; Gong, X. Z.

Significant progress has recently been made on EAST in the 2014 campaign, including the enhanced CW H&CD system over 20MW heating power (LHCD, ICRH and NBI), more than 70 diagnostics, ITER-like W-monoblock on upper divertor, two inner cryo-pumps and RMP coils, enabling EAST to investigate long pulse H mode operation with dominant electron heating and low torque to address the critical issues for ITER. H-mode plasmas were achieved by new H&CD system or 4.6GHz LHCD alone for the first time. Long pulse high performance H mode has been obtained by LHCD alone up to 28s at H{sub 98}∼1.2 or bymore » combing of ICRH and LHCD, no or small ELM was found in RF plasmas, which is essential for steady state operation in the future Tokamak. Plasma operation in low collision regimes were implemented by new 4.6GHz LHCD with core Te∼4.5keV. The non-inductive scenarios with high performance at high bootstrap current fraction have been demonstrated in RF dominated regimes for long pulse operation. Near full non-inductive CD discharges have been achieved. In addition, effective heating and decoupling method under multi-transmitter for ICRF system were developed in this campaign, etc. EAST could be in operation with over 30MW CW heating and current drive power (LHCD ICRH NBI and ECRH), enhanced diagnostic capabilities and full actively-cooled metal wall from 2015. It will therefore allow to access new confinement regimes and to extend these regimes towards to steady state operation.« less

Update on narrow band imaging in disorders of the upper gastrointestinal tract.

PubMed

Singh, Rajvinder; Lee, Shok Y; Vijay, Nimal; Sharma, Prateek; Uedo, Noriya

2014-03-01

With the ever-increasing concern regarding morbidity and mortality associated with diseases of the gastrointestinal tract, the importance of an effective and efficient diagnostic tool cannot be overstated. The standard of care currently is an examination using conventional white light endoscopy. This approach may occasionally overlook areas exhibiting a premalignant change. Numerous image-enhanced modalities have been recently introduced. Narrow band imaging (NBI) appears to be the most prominent of these and perhaps the most commonly used. Thepresent review will focus on some of the newer studies on NBI and its utility in the diagnosis of malignant, pre-malignant and chronic inflammatory conditions of the upper gastrointestinal tract. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Self-consistent field theory of polymer-ionic molecule complexation.

PubMed

Nakamura, Issei; Shi, An-Chang

2010-05-21

A self-consistent field theory is developed for polymers that are capable of binding small ionic molecules (adsorbates). The polymer-ionic molecule association is described by Ising-like binding variables, C(i) ((a))(kDelta)(=0 or 1), whose average determines the number of adsorbed molecules, n(BI). Polymer gelation can occur through polymer-ionic molecule complexation in our model. For polymer-polymer cross-links through the ionic molecules, three types of solutions for n(BI) are obtained, depending on the equilibrium constant of single-ion binding. Spinodal lines calculated from the mean-field free energy exhibit closed-loop regions where the homogeneous phase becomes unstable. This phase instability is driven by the excluded-volume interaction due to the single occupancy of ion-binding sites on the polymers. Moreover, sol-gel transitions are examined using a critical degree of conversion. A gel phase is induced when the concentration of adsorbates is increased. At a higher concentration of the adsorbates, however, a re-entrance from a gel phase into a sol phase arises from the correlation between unoccupied and occupied ion-binding sites. The theory is applied to a model system, poly(vinyl alcohol) and borate ion in aqueous solution with sodium chloride. Good agreement between theory and experiment is obtained.

Control of Internal Transport Barriers in Magnetically Confined Fusion Plasmas

NASA Astrophysics Data System (ADS)

Panta, Soma; Newman, David; Sanchez, Raul; Terry, Paul

2016-10-01

In magnetic confinement fusion devices the best performance often involves some sort of transport barriers to reduce the energy and particle flow from core to edge. Those barriers create gradients in the temperature and density profiles. If gradients in the profiles are too steep that can lead to instabilities and the system collapses. Control of these barriers is therefore an important challenge for fusion devices (burning plasmas). In this work we focus on the dynamics of internal transport barriers. Using a simple 7 field transport model, extensively used for barrier dynamics and control studies, we explore the use of RF heating to control the local gradients and therefore the growth rates and shearing rates for barrier initiation and control in self-heated fusion plasmas. Ion channel barriers can be formed in self-heated plasmas with some NBI heating but electron channel barriers are very sensitive. They can be formed in self-heated plasmas with additional auxiliary heating i.e. NBI and radio-frequency(RF). Using RF heating on both electrons and ions at proper locations, electron channel barriers along with ion channel barriers can be formed and removed demonstrating a control technique. Investigating the role of pellet injection in controlling the barriers is our next goal. Work supported by DOE Grant DE-FG02-04ER54741.

"Leopard skin sign": the use of narrow-band imaging with magnification endoscopy in celiac disease.

PubMed

Tchekmedyian, Asadur J; Coronel, Emmanuel; Czul, Frank

2014-01-01

Celiac Disease (CD) is an immune reaction to gluten containing foods such as rye, wheat and barley. This condition affects individuals with a genetic predisposition; it targets the small bowel and may cause symptoms including diarrhea, malabsorption, weight loss, abdominal pain and bloating. The diagnosis is made by serologic testing of celiac-specific antibodies and confirmed by histology. Certain endoscopic characteristics, such as scalloping, reduction in the number of folds, mosaic-pattern mucosa or nodular mucosa, are suggestive of CD and can be visualized under white light endoscopy. Due to its low sensitivity, endoscopy alone is not recommended to diagnose CD; however, enhanced visual identification of suspected mucosal abnormalities through the use of new technologies, such as narrow band imaging with magnification (NBI-ME), could assist in targeting biopsies and thereby increasing the sensitivity of endoscopy. This is a case series of seven patients with serologic and histologic diagnoses of CD who underwent upper endoscopies with NBI-ME imaging technology as part of their CD evaluation. By employing this imaging technology, we could identify patchy atrophy sites in a mosaic pattern, with flattened villi and alteration of the central capillaries of the duodenal mucosa. We refer to this epithelial pattern as "Leopard Skin Sign". Since epithelial lesions are easily seen using NBI-ME, we found it beneficial for identifying and targeting biopsy sites. Larger prospective studies are warranted to confirm our findings.

Indian Test Facility (INTF) and its updates

NASA Astrophysics Data System (ADS)

Bandyopadhyay, M.; Chakraborty, A.; Rotti, C.; Joshi, J.; Patel, H.; Yadav, A.; Shah, S.; Tyagi, H.; Parmar, D.; Sudhir, Dass; Gahlaut, A.; Bansal, G.; Soni, J.; Pandya, K.; Pandey, R.; Yadav, R.; Nagaraju, M. V.; Mahesh, V.; Pillai, S.; Sharma, D.; Singh, D.; Bhuyan, M.; Mistry, H.; Parmar, K.; Patel, M.; Patel, K.; Prajapati, B.; Shishangiya, H.; Vishnudev, M.; Bhagora, J.

2017-04-01

To characterize ITER Diagnostic Neutral Beam (DNB) system with full specification and to support IPR’s negative ion beam based neutral beam injector (NBI) system development program, a R&D facility, named INTF is under commissioning phase. Implementation of a successful DNB at ITER requires several challenges need to be overcome. These issues are related to the negative ion production, its neutralization and corresponding neutral beam transport over the path lengths of ∼ 20.67 m to reach ITER plasma. DNB is a procurement package for INDIA, as an in-kind contribution to ITER. Since ITER is considered as a nuclear facility, minimum diagnostic systems, linked with safe operation of the machine are planned to be incorporated in it and so there is difficulty to characterize DNB after onsite commissioning. Therefore, the delivery of DNB to ITER will be benefited if DNB is operated and characterized prior to onsite commissioning. INTF has been envisaged to be operational with the large size ion source activities in the similar timeline, as with the SPIDER (RFX, Padova) facility. This paper describes some of the development updates of the facility.

Operating characteristics of a new ion source for KSTAR neutral beam injection system.

PubMed

Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

2014-02-01

A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.

Dependence of Edge Profiles and Stability on Neutral Beam Power in NSTX

NASA Astrophysics Data System (ADS)

Travis, P.; Canal, G. P.; Osborne, T. H.; Maingi, R.; Sabbagh, S. A.; NSTX-U Team

2016-10-01

Studying the effect of neutral beam injected (NBI) power on edge plasma profiles and magnetohydrodynamic (MHD) stability is central to the understanding of edge-localized modes (ELMs). Higher heating power should quicken the development of pressure and current-driven peeling-ballooning modes. NSTX ELMy H-mode discharges with NBI power of 4, 5 and 6 MW were analyzed with a python-based set of analysis tools that fit plasma profiles, compute kinetic equilibria, and evaluate the MHD stability with the code ELITE. Electron density and temperature from Thomson scattering measurements, and ion density, temperature, and rotation from Charge Exchange Recombination Spectroscopy were inputs to the kinetic equilibrium fits. The power scan provides an opportunity to compare the stability calculations from the ELITE (ideal) and M3D-C1 (resistive) codes. Preliminary analysis shows that edge pressure profiles for the 5 and 6 MW discharges are comparable, suggesting they both reach a stability boundary. The 4 MW case shows lower edge pressure, which is likely limited by edge transport below the edge stability boundary. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program.

Effects of MHD instabilities on neutral beam current drive

NASA Astrophysics Data System (ADS)

Podestà, M.; Gorelenkova, M.; Darrow, D. S.; Fredrickson, E. D.; Gerhardt, S. P.; White, R. B.

2015-05-01

Neutral beam injection (NBI) is one of the primary tools foreseen for heating, current drive (CD) and q-profile control in future fusion reactors such as ITER and a Fusion Nuclear Science Facility. However, fast ions from NBI may also provide the drive for energetic particle-driven instabilities (e.g. Alfvénic modes (AEs)), which in turn redistribute fast ions in both space and energy, thus hampering the control capabilities and overall efficiency of NB-driven current. Based on experiments on the NSTX tokamak (M. Ono et al 2000 Nucl. Fusion 40 557), the effects of AEs and other low-frequency magneto-hydrodynamic instabilities on NB-CD efficiency are investigated. A new fast ion transport model, which accounts for particle transport in phase space as required for resonant AE perturbations, is utilized to obtain consistent simulations of NB-CD through the tokamak transport code TRANSP. It is found that instabilities do indeed reduce the NB-driven current density over most of the plasma radius by up to ∼50%. Moreover, the details of the current profile evolution are sensitive to the specific model used to mimic the interaction between NB ions and instabilities. Implications for fast ion transport modeling in integrated tokamak simulations are briefly discussed.

The ITER Neutral Beam Test Facility towards SPIDER operation

NASA Astrophysics Data System (ADS)

Toigo, V.; Dal Bello, S.; Gaio, E.; Luchetta, A.; Pasqualotto, R.; Zaccaria, P.; Bigi, M.; Chitarin, G.; Marcuzzi, D.; Pomaro, N.; Serianni, G.; Agostinetti, P.; Agostini, M.; Antoni, V.; Aprile, D.; Baltador, C.; Barbisan, M.; Battistella, M.; Boldrin, M.; Brombin, M.; Dalla Palma, M.; De Lorenzi, A.; Delogu, R.; De Muri, M.; Fellin, F.; Ferro, A.; Gambetta, G.; Grando, L.; Jain, P.; Maistrello, A.; Manduchi, G.; Marconato, N.; Pavei, M.; Peruzzo, S.; Pilan, N.; Pimazzoni, A.; Piovan, R.; Recchia, M.; Rizzolo, A.; Sartori, E.; Siragusa, M.; Spada, E.; Spagnolo, S.; Spolaore, M.; Taliercio, C.; Valente, M.; Veltri, P.; Zamengo, A.; Zaniol, B.; Zanotto, L.; Zaupa, M.; Boilson, D.; Graceffa, J.; Svensson, L.; Schunke, B.; Decamps, H.; Urbani, M.; Kushwah, M.; Chareyre, J.; Singh, M.; Bonicelli, T.; Agarici, G.; Garbuglia, A.; Masiello, A.; Paolucci, F.; Simon, M.; Bailly-Maitre, L.; Bragulat, E.; Gomez, G.; Gutierrez, D.; Mico, G.; Moreno, J.-F.; Pilard, V.; Chakraborty, A.; Baruah, U.; Rotti, C.; Patel, H.; Nagaraju, M. V.; Singh, N. P.; Patel, A.; Dhola, H.; Raval, B.; Fantz, U.; Fröschle, M.; Heinemann, B.; Kraus, W.; Nocentini, R.; Riedl, R.; Schiesko, L.; Wimmer, C.; Wünderlich, D.; Cavenago, M.; Croci, G.; Gorini, G.; Rebai, M.; Muraro, A.; Tardocchi, M.; Hemsworth, R.

2017-08-01

SPIDER is one of two projects of the ITER Neutral Beam Test Facility under construction in Padova, Italy, at the Consorzio RFX premises. It will have a 100 keV beam source with a full-size prototype of the radiofrequency ion source for the ITER neutral beam injector (NBI) and also, similar to the ITER diagnostic neutral beam, it is designed to operate with a pulse length of up to 3600 s, featuring an ITER-like magnetic filter field configuration (for high extraction of negative ions) and caesium oven (for high production of negative ions) layout as well as a wide set of diagnostics. These features will allow a reproduction of the ion source operation in ITER, which cannot be done in any other existing test facility. SPIDER realization is well advanced and the first operation is expected at the beginning of 2018, with the mission of achieving the ITER heating and diagnostic NBI ion source requirements and of improving its performance in terms of reliability and availability. This paper mainly focuses on the preparation of the first SPIDER operations—integration and testing of SPIDER components, completion and implementation of diagnostics and control and formulation of operation and research plan, based on a staged strategy.

Effects of MHD instabilities on neutral beam current drive

DOE PAGES

Podestà, M.; Gorelenkova, M.; Darrow, D. S.; ...

2015-04-17

One of the primary tools foreseen for heating, current drive (CD) and q-profile control in future fusion reactors such as ITER and a Fusion Nuclear Science Facility is the neutral beam injection (NBI). However, fast ions from NBI may also provide the drive for energetic particle-driven instabilities (e.g. Alfvénic modes (AEs)), which in turn redistribute fast ions in both space and energy, thus hampering the control capabilities and overall efficiency of NB-driven current. Based on experiments on the NSTX tokamak (M. Ono et al 2000 Nucl. Fusion 40 557), the effects of AEs and other low-frequency magneto-hydrodynamic instabilities on NB-CDmore » efficiency are investigated. When looking at the new fast ion transport model, which accounts for particle transport in phase space as required for resonant AE perturbations, is utilized to obtain consistent simulations of NB-CD through the tokamak transport code TRANSP. It is found that instabilities do indeed reduce the NB-driven current density over most of the plasma radius by up to ~50%. Moreover, the details of the current profile evolution are sensitive to the specific model used to mimic the interaction between NB ions and instabilities. Finally, implications for fast ion transport modeling in integrated tokamak simulations are briefly discussed.« less

Combined magnetic and kinetic control of advanced tokamak steady state scenarios based on semi-empirical modelling

NASA Astrophysics Data System (ADS)

Moreau, D.; Artaud, J. F.; Ferron, J. R.; Holcomb, C. T.; Humphreys, D. A.; Liu, F.; Luce, T. C.; Park, J. M.; Prater, R.; Turco, F.; Walker, M. L.

2015-06-01

This paper shows that semi-empirical data-driven models based on a two-time-scale approximation for the magnetic and kinetic control of advanced tokamak (AT) scenarios can be advantageously identified from simulated rather than real data, and used for control design. The method is applied to the combined control of the safety factor profile, q(x), and normalized pressure parameter, βN, using DIII-D parameters and actuators (on-axis co-current neutral beam injection (NBI) power, off-axis co-current NBI power, electron cyclotron current drive power, and ohmic coil). The approximate plasma response model was identified from simulated open-loop data obtained using a rapidly converging plasma transport code, METIS, which includes an MHD equilibrium and current diffusion solver, and combines plasma transport nonlinearity with 0D scaling laws and 1.5D ordinary differential equations. The paper discusses the results of closed-loop METIS simulations, using the near-optimal ARTAEMIS control algorithm (Moreau D et al 2013 Nucl. Fusion 53 063020) for steady state AT operation. With feedforward plus feedback control, the steady state target q-profile and βN are satisfactorily tracked with a time scale of about 10 s, despite large disturbances applied to the feedforward powers and plasma parameters. The robustness of the control algorithm with respect to disturbances of the H&CD actuators and of plasma parameters such as the H-factor, plasma density and effective charge, is also shown.

Improved Management of the Nile River Basin Through Modeling the Sudd, a Wetland with Vital Socioeconomic and Environmental Services

NASA Astrophysics Data System (ADS)

Di Vittorio, C.; Georgakakos, A. P.

2017-12-01

The Sudd is a vast, remote wetland in South Sudan and a vital component of the Nile River Basin. While decision support tools like the Nile Decision Support Tool (Nile DST) estimate the amount of water flowing through the Sudd, they do not account for other wetland processes that sustain the ecosystem diversity and the pastoral way of life for nearly two million people who live in the area (Howell et al. 1988). An accurate hydrologic model of the Sudd would enable policy makers to appreciate and manage it in a way that benefits local inhabitants as well as the 500 million people living within the Nile region (NBI, 2016). Currently, the most widely accepted model of the Sudd was developed by Sutcliffe and Parks (1999) and is a lumped mass balance model that accounts for key water fluxes. Estimates of the aerial extent of flooding obtained from satellite and airborne imagery on a few dates were used to calibrate the model parameters over the 1905-1983 period. During the AGU Fall 2016 meeting, we presented a method for deriving the dynamic flooding extents of the Sudd on a monthly temporal resolution from 2000-2015 using MODIS (Moderate Resolution Imaging Spectrometer) land surface reflectance data (Di Vittorio & Georgakakos, 2017 in press). In the study presented here, we have used this new information to evaluate the Sutcliffe and Park's model, highlight its shortcomings, and suggest alternative modeling approaches that are accurate enough to incorporate into water management models. The alternative modelling approaches include statistical and physically based models, and the incorporation of satellite-based hydrometeorlogical data sets. This improved hydrologic model will allow stakeholders in this sensitive world region to better understand how current and future climate and water management scenarios will impact the Sudd ecosystem and local economy. References: Di Vittorio, C. A., Georgakakos, A.P. (2017). Land cover classification and wetland inundation mapping using MODIS. Remote Sensing of Environment. In press.Howell, P., Lock, M., & Cobb, S. (1988). The Jonglei Canal impact and opportunity. Cambridge: Cambridge University Press. NBI, N.B.I. (2016). Annual Corporate Report. Sutcliffe, J.V., & Parks, Y.P. (1999). The Hydrology of the Nile. Wallingford, UK.

Experimental observation of multi-scale interactions among kink /tearing modes and high-frequency fluctuations in the HL-2A core NBI plasmas

NASA Astrophysics Data System (ADS)

Chen, W.; Jiang, M.; Xu, Y.; Shi, P. W.; Yu, L. M.; Ding, X. T.; Shi, Z. B.; Ji, X. Q.; Yu, D. L.; Li, Y. G.; Yang, Z. C.; Zhong, W. L.; Qiu, Z. Y.; Li, J. Q.; Dong, J. Q.; Yang, Q. W.; Liu, Yi.; Yan, L. W.; Xu, M.; Duan, X. R.

2017-11-01

Multi-scale interactions have been observed recently in the HL-2A core NBI plasmas, including the synchronous coupling between m/n=1/1 kink mode and m/n=2/1 tearing mode, nonlinear couplings of TAE/BAE and m/n=2/1 TM near q=2 surface, AITG/KBM/BAE and m/n=1/1 kink mode near q=1 surface, and between m/n=1/1 kink mode and high-frequency turbulence. Experimental results suggest that several couplings can exist simultaneously, Alfvenic fluctuations have an important contribution to the high-frequency turbulence spectra, and the couplings reveal the electromagnetic character. Multi-scale interactions via the nonlinear modulation process maybe enhance plasma transport and trigger sawtooth-crash onset.

Improvement of a plasma uniformity of the 2nd ion source of KSTAR neutral beam injector.

PubMed

Jeong, S H; Kim, T S; Lee, K W; Chang, D H; In, S R; Bae, Y S

2014-02-01

The 2nd ion source of KSTAR (Korea Superconducting Tokamak Advanced Research) NBI (Neutral Beam Injector) had been developed and operated since last year. A calorimetric analysis revealed that the heat load of the back plate of the ion source is relatively higher than that of the 1st ion source of KSTAR NBI. The spatial plasma uniformity of the ion source is not good. Therefore, we intended to identify factors affecting the uniformity of a plasma density and improve it. We estimated the effects of a direction of filament current and a magnetic field configuration of the plasma generator on the plasma uniformity. We also verified that the operation conditions of an ion source could change a uniformity of the plasma density of an ion source.

RF generator interlock by plasma grid bias current - An alternate to Hα interlock

NASA Astrophysics Data System (ADS)

Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

2017-08-01

ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma operation, BC rises due to the presence of plasma electrons, almost in the same timescale as plasma light detection system and so, BC signal can also be used as RFG interlock. The BC signal transmission is through optical isolation to reduce noise interference with the signal. The response of the current monitoring signal available from the PG power supply of ROBIN is quite slow (in the order of few tens of milliseconds). Therefore, a fast response current detection electronic circuit having the ability to generate a PG current detection pulse with adjustable threshold set point has been developed and integrated with ROBIN, and the above concept has been demonstrated in ROBIN recently. The present paper will discuss this experimental activity and its results.

Comparative analysis of core heat transport of JET high density H-mode plasmas in carbon wall and ITER-like wall

NASA Astrophysics Data System (ADS)

Kim, Hyun-Tae; Romanelli, M.; Voitsekhovitch, I.; Koskela, T.; Conboy, J.; Giroud, C.; Maddison, G.; Joffrin, E.; contributors, JET

2015-06-01

A consistent deterioration of global confinement in H-mode experiments has been observed in JET [1] following the replacement of all carbon plasma facing components (PFCs) with an all metal (‘ITER-like’) wall (ILW). This has been correlated to the observed degradation of the pedestal confinement, as lower electron temperature (Te) values are routinely measured at the top of the edge barrier region. A comparative investigation of core heat transport in JET-ILW and JET-CW (carbon wall) discharges has been performed, to assess whether core confinement has also been affected by the wall change. The results presented here have been obtained by analysing a set of discharges consisting of high density JET-ILW H-mode plasmas and comparing them against their counterpart discharges in JET-CW having similar global operational parameters. The set contains 10 baseline ({βN}=1.5∼ 2 ) discharge-pairs with 2.7 T toroidal magnetic field, 2.5 MA plasma current, and 14 to 17 MW of neutral beam injection (NBI) heating. Based on a Te profile analysis using high resolution Thomson scattering (HRTS) data, the Te profile peaking (i.e. core Te (ρ = 0.3) / edge Te (ρ = 0.7)) is found to be similar, and weakly dependent on edge Te, for both JET-ILW and JET-CW discharges. When ILW discharges are seeded with N2, core and edge Te both increase to maintain a similar peaking factor. The change in core confinement is addressed with interpretative TRANSP simulations. It is found that JET-ILW H-mode plasmas have higher NBI power deposition to electrons and lower NBI power deposition to ions as compared to the JET-CW counterparts. This is an effect of the lower electron temperature at the top of the pedestal. As a result, the core electron energy confinement time is reduced in JET-ILW discharges, but the core ion energy confinement time is not decreased. Overall, the core energy confinement is found to be the same in the JET-ILW discharges compared to the JET-CW counterparts.

A modular and programmable development platform for capsule endoscopy system.

PubMed

Khan, Tareq Hasan; Shrestha, Ravi; Wahid, Khan A

2014-06-01

The state-of-the-art capsule endoscopy (CE) technology offers painless examination for the patients and the ability to examine the interior of the gastrointestinal tract by a noninvasive procedure for the gastroenterologists. In this work, a modular and flexible CE development system platform consisting of a miniature field programmable gate array (FPGA) based electronic capsule, a microcontroller based portable data recorder unit and computer software is designed and developed. Due to the flexible and reprogrammable nature of the system, various image processing and compression algorithms can be tested in the design without requiring any hardware change. The designed capsule prototype supports various imaging modes including white light imaging (WLI) and narrow band imaging (NBI), and communicates with the data recorder in full duplex fashion, which enables configuring the image size and imaging mode in real time during examination. A low complexity image compressor based on a novel color-space is implemented inside the capsule to reduce the amount of RF transmission data. The data recorder contains graphical LCD for real time image viewing and SD cards for storing image data. Data can be uploaded to a computer or Smartphone by SD card, USB interface or by wireless Bluetooth link. Computer software is developed that decompresses and reconstructs images. The fabricated capsule PCBs have a diameter of 16 mm. An ex-vivo animal testing has also been conducted to validate the results.

The Role of Combined ICRF and NBI Heating in JET Hybrid Plasmas in Quest for High D-T Fusion Yield

NASA Astrophysics Data System (ADS)

Mantsinen, Mervi; Challis, Clive; Frigione, Domenico; Graves, Jonathan; Hobirk, Joerg; Belonohy, Eva; Czarnecka, Agata; Eriksson, Jacob; Gallart, Dani; Goniche, Marc; Hellesen, Carl; Jacquet, Philippe; Joffrin, Emmanuel; King, Damian; Krawczyk, Natalia; Lennholm, Morten; Lerche, Ernesto; Pawelec, Ewa; Sips, George; Solano, Emilia R.; Tsalas, Maximos; Valisa, Marco

2017-10-01

Combined ICRF and NBI heating played a key role in achieving the world-record fusion yield in the first deuterium-tritium campaign at the JET tokamak in 1997. The current plans for JET include new experiments with deuterium-tritium (D-T) plasmas with more ITER-like conditions given the recently installed ITER-like wall (ILW). In the 2015-2016 campaigns, significant efforts have been devoted to the development of high-performance plasma scenarios compatible with ILW in preparation of the forthcoming D-T campaign. Good progress was made in both the inductive (baseline) and the hybrid scenario: a new record JET ILW fusion yield with a significantly extended duration of the high-performance phase was achieved. This paper reports on the progress with the hybrid scenario which is a candidate for ITER longpulse operation (˜1000 s) thanks to its improved normalized confinement, reduced plasma current and higher plasma beta with respect to the ITER reference baseline scenario. The combined NBI+ICRF power in the hybrid scenario was increased to 33 MW and the record fusion yield, averaged over 100 ms, to 2.9x1016 neutrons/s from the 2014 ILW fusion record of 2.3x1016 neutrons/s. Impurity control with ICRF waves was one of the key means for extending the duration of the high-performance phase. The main results are reviewed covering both key core and edge plasma issues.

MST Pellet Injector Upgrades to Probe Beta and Density Limits and Impurity Particle Transport

NASA Astrophysics Data System (ADS)

Caspary, K. J.; Chapman, B. E.; Anderson, J. K.; Kumar, S. T. A.; Limbach, S. T.; Oliva, S. P.; Sarff, J. S.; Waksman, J.; Combs, S. K.; Foust, C. R.

2012-10-01

Upgrades to the pellet injector on MST will allow for significantly increased fueling capability enabling density limit studies for previously unavailable density regimes. Thus far, Greenwald fractions of 1.2 and 1.5 have been achieved in 500 kA and 200 kA improved confinement plasmas, respectively. The size of the pellet guide tubes, which constrain the lateral motion of the pellet in flight, was increased to accommodate pellets of up to 4.0 mm in diameter, capable of fueling to Greenwald fractions > 2.0 for MST's peak current of 600 kA. Exploring the effect of increased density on NBI deposition shows that for MST's NBI, core deposition of 25 keV neutrals is optimized for densities of 2 -- 3 x 10^19 m-3. This is key for beta limit studies in pellet fueled discharges with improved confinement where maximum NBI heating is desired. In addition, a modification to the injector has allowed operation using alternative pellet fuels with triple points significantly higher than that of deuterium (18.7 K). A small flow of helium into the pellet formation vacuum chamber introduces a controllable heat source capable of elevating the operating temperature of the injector. Injection of methane pellets with a triple point of 90.7 K results in a 12-fold increase in the core carbon impurity density. The flow rate is easily adjusted to optimize injector operating temperature for other fuel gases as well. Work supported by US DoE.

Synthetic NPA diagnostic for energetic particles in JET plasmas

NASA Astrophysics Data System (ADS)

Varje, J.; Sirén, P.; Weisen, H.; Kurki-Suonio, T.; Äkäslompolo, S.; contributors, JET

2017-11-01

Neutral particle analysis (NPA) is one of the few methods for diagnosing fast ions inside a plasma by measuring neutral atom fluxes emitted due to charge exchange reactions. The JET tokamak features an NPA diagnostic which measures neutral atom fluxes and energy spectra simultaneously for hydrogen, deuterium and tritium species. A synthetic NPA diagnostic has been developed and used to interpret these measurements to diagnose energetic particles in JET plasmas with neutral beam injection (NBI) heating. The synthetic NPA diagnostic performs a Monte Carlo calculation of the neutral atom fluxes in a realistic geometry. The 4D fast ion distributions, representing NBI ions, were simulated using the Monte Carlo orbit-following code ASCOT. Neutral atom density profiles were calculated using the FRANTIC neutral code in the JINTRAC modelling suite. Additionally, for rapid analysis, a scan of neutral profiles was precalculated with FRANTIC for a range of typical plasma parameters. These were taken from the JETPEAK database, which includes a comprehensive set of data from the flat-top phases of nearly all discharges in recent JET campaigns. The synthetic diagnostic was applied to various JET plasmas in the recent hydrogen campaign where different hydrogen/deuterium mixtures and NBI configurations were used. The simulated neutral fluxes from the fast ion distributions were found to agree with the measured fluxes, reproducing the slowing-down profiles for different beam isotopes and energies and quantitatively estimating the fraction of hydrogen and deuterium fast ions.

Optimizing the current ramp-up phase for the hybrid ITER scenario

NASA Astrophysics Data System (ADS)

Hogeweij, G. M. D.; Artaud, J.-F.; Casper, T. A.; Citrin, J.; Imbeaux, F.; Köchl, F.; Litaudon, X.; Voitsekhovitch, I.; the ITM-TF ITER Scenario Modelling Group

2013-01-01

The current ramp-up phase for the ITER hybrid scenario is analysed with the CRONOS integrated modelling suite. The simulations presented in this paper show that the heating systems available at ITER allow, within the operational limits, the attainment of a hybrid q profile at the end of the current ramp-up. A reference ramp-up scenario is reached by a combination of NBI, ECCD (UPL) and LHCD. A heating scheme with only NBI and ECCD can also reach the target q profile; however, LHCD can play a crucial role in reducing the flux consumption during the ramp-up phase. The optimum heating scheme depends on the chosen transport model, and on assumptions of parameters like ne peaking, edge Te,i and Zeff. The sensitivity of the current diffusion on parameters that are not easily controlled, shows that development of real-time control is important to reach the target q profile. A first step in that direction has been indicated in this paper. Minimizing resistive flux consumption and optimizing the q profile turn out to be conflicting requirements. A trade-off between these two requirements has to be made. In this paper it is shown that fast current ramp with L-mode current overshoot is at the one extreme, i.e. the optimum q profile at the cost of increased resistive flux consumption, whereas early H-mode transition is at the other extreme.

Recent Updates in the Endoscopic Diagnosis of Barrett's Oesophagus.

PubMed

Sharma, Neel; Ho, Khek Yu

2016-10-01

Barrett's oesophagus (BO) is a premalignant condition associated with the development of oesophageal adenocarcinoma (OAC). Despite the low risk of progression per annum, OAC is associated with significant morbidity and mortality, with an estimated 5-year survival of 10%. Furthermore, the incidence of OAC continues to rise globally. Therefore, it is imperative to detect the premalignant phase of BO and follow up such patients accordingly. The mainstay diagnosis of BO is endoscopy and biopsy sampling. However, limitations with white light endoscopy (WLE) and undertaking biopsies have shifted the current focus towards real-time image analysis. Utilization of additional tools such as chromoendoscopy, narrow-band imaging (NBI), confocal laser endomicroscopy (CLE), and optical coherence tomography (OCT) are proving beneficial. Furthermore, it is also becoming more apparent that often these tools are utilized by experts in the field. Therefore, for the non-expert, training in these systems is key. Currently as yet, the methodologies used for training optimization require further inquiry. (1) Real-time imaging can serve to minimize excess biopsies. (2) Tools such as chromoendoscopy, NBI, CLE, and OCT can help to compliment WLE. WLE is associated with limited sensitivity. Biopsy sampling is cost-ineffective and associated with sampling error. Hence, from a practical perspective, endoscopists should aim to utilize additional tools to help in real-time image interpretation and minimize an overreliance on histology.

Recent Updates in the Endoscopic Diagnosis of Barrett's Oesophagus

PubMed Central

Sharma, Neel; Ho, Khek Yu

2016-01-01

Background Barrett's oesophagus (BO) is a premalignant condition associated with the development of oesophageal adenocarcinoma (OAC). Despite the low risk of progression per annum, OAC is associated with significant morbidity and mortality, with an estimated 5-year survival of 10%. Furthermore, the incidence of OAC continues to rise globally. Therefore, it is imperative to detect the premalignant phase of BO and follow up such patients accordingly. Summary The mainstay diagnosis of BO is endoscopy and biopsy sampling. However, limitations with white light endoscopy (WLE) and undertaking biopsies have shifted the current focus towards real-time image analysis. Utilization of additional tools such as chromoendoscopy, narrow-band imaging (NBI), confocal laser endomicroscopy (CLE), and optical coherence tomography (OCT) are proving beneficial. Furthermore, it is also becoming more apparent that often these tools are utilized by experts in the field. Therefore, for the non-expert, training in these systems is key. Currently as yet, the methodologies used for training optimization require further inquiry. Key Message (1) Real-time imaging can serve to minimize excess biopsies. (2) Tools such as chromoendoscopy, NBI, CLE, and OCT can help to compliment WLE. Practical Implications WLE is associated with limited sensitivity. Biopsy sampling is cost-ineffective and associated with sampling error. Hence, from a practical perspective, endoscopists should aim to utilize additional tools to help in real-time image interpretation and minimize an overreliance on histology. PMID:27904863

Applications of Artificial Intelligence in Voice Recognition Systems in Micro-Computers.

DTIC Science & Technology

1982-03-01

DELTAO THEN 1290 1050 IF ANS$(I) = "HAIN MENU THEN 320 1060 IF ANS$(I) - " ABORTO THEN 3150 1070 IF ANS$(I) - 󈧄 BACK’ THEN 3590 1080 NEXT I 1090... ABORTO THEN 3150 1660 NEXT I 1670 SOTO 3350 3 REM’ ERROR PACK 1680 STOP 1690 REM SHIPS MENU 1700 REM------------ 1710 HOME : VTAB 5 :HTAB 15 :PRINT...IF ANS*(I) - PROFILESO THEN 3100 2470 IF IS$(I) - "MIN MENU" THEN 320 24Sf IF NB$(I) - "G0 BACK" THEN 3590 2490 IF ANS$(I) - " ABORTO THEN 3150 2500

Heating and current drive on NSTX

NASA Astrophysics Data System (ADS)

Wilson, J. R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C. K.; Rogers, J. H.; Schilling, G.

1997-04-01

Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (˜45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation.

A Critical Fast Ion Beta in the Madison Symmetric Torus Reversed Field Pinch

NASA Astrophysics Data System (ADS)

Capecchi, William J.

The first fast-ion profile measurements have been made in a reversed-field pinch (RFP) plasma. A large population of fast-ions are deposited in the core of the Madison Symmetric Torus (MST) through use of a 1 MW neutral beam injector (NBI) giving rise to a variety of beam-driven instabilities. One such mode, the energetic-particle mode (EPM) has been shown to reduce fast-ion content in MST, evident through drops in signal levels of the advanced neutral particle analyzer (ANPA). EPMs in MST appear as bursts of magnetic fluctuations at a lab frequency of ˜100 kHz reaching peak amplitude and decaying away within 100 microseconds. A burst ensemble of the neutron data does not reveal a drop in neutron emission across a burst, implying the population of fast-ions transported by a burst constitute a small fraction of the total. The burst may also pitch-angle scatter out of the ANPA phase space or be transported to mid-radius where charge-exchange with the background neutrals or fast-ion orbit stochasticity may reduce fast-ion confinement. Data gathered from the expanded neutron diagnostic suite including a new collimated neutron detector (CiNDe) was used to reconstruct the fast-ion profile in MST and measure critical fast-ion beta quantities. Measurements were made in plasma conditions with varying magnetic field strength in order to investigate the interplay between the energetic particle (EP) drive and Alfven continuum damping. The measured values of the core fast-ion beta (7.5% (1.2%) in 300 (500) kA plasmas) are reduced from classical predictions (TRANSP predicts up to 10% core value) due to EPM activity. The frequency, magnitude, and rate of occurrence of the bursts depends on the tearing mode amplitude, Alfven continuum damping rate, fast-ion profile shape, and resonant orbit dynamics. Marginal stability was reached in both moderate- (300 kA) and high- (500 kA) current discharges, marked by sustained EPM activity and a saturated global neutron signal during NBI. The difference in profile shape is interpreted to be related to the core-most resonant tearing mode amplitude, as a larger core magnetic island moves the location of steepest fast-ion gradient further out in radius, resulting in lower confinement of the fast-ions. The reconstructed profile is more strongly peaked at lower current, consistent with a lower measured core-most tearing mode amplitude. A larger dataset at lower current gives enough temporal resolution to investigate the evolution of the fast-ion profile. The suppression of the core-most tearing mode amplitude during NBI results in a rapid and dynamically evolving fast-ion profile at the beginning of the NBI discharge and results in an initially broader profile early evolving into a more strongly peaked profile later in the NBI discharge.

Rational-q Triggered Transport Changes With Varying Toroidal Rotation in DIII-D

NASA Astrophysics Data System (ADS)

Austin, M. E.; Burrell, K. H.; Waltz, R. E.; van Zeeland, M. A.; McKee, G. R.; Shafer, M. W.; Rhodes, T. L.

2007-11-01

Comparison of rational-q triggered ITBs in discharges with varying toroidal torque injection was carried out. Experiments were conducted in negative central shear discharges with different mixes of co/counter neutral beam injection (NBI) that altered the equilibrium ExB shear in conditions where transient improvements in transport occur near integer qmin values. The transport changes were seen in high and low rotation cases; however, the latter discharges did not transition to improved core confinement. Observations support the model that sufficient background ExB shear is required for barrier formation and zonal flow effects at integer qmin act as trigger in this case. The lack of TAE modes in the balanced injection cases indicates they are not linked to the transient confinement improvement. Fluctuation data obtained in co and balanced NBI show similar reductions in turbulence near integer qmin as well as poloidal velocity excursions that may be further evidence of zonal flow.

Vacuum Surface Flashover Characteristics and Secondary Electron Emission Characteristics of Epoxy Resin and FRP Insulator

NASA Astrophysics Data System (ADS)

Yamano, Yasushi; Takahashi, Masahiro; Kobayashi, Shinichi; Hanada, Masaya; Ikeda, Yoshitaka

Neutral beam injectors (NBI) used for JT-60 are required to generate negative ions of 500 keV energies. To produce such high-energy ions, the electrostatic accelerators consisting of 3-stage of electrodes and three insulator rings are applied. The insulators are made of Fiberglass Reinforced Plastic (FRP) which is composed of epoxy resin and glass fibers. The surface discharges along the insulators are one of the most serious problems in the development of NBI. To increase the hold-off voltage against surface flashover events, it is necessary to investigate the FRP and epoxy resin insulator properties related to surface discharges in vacuum. This paper describes surface flashover characteristics for epoxy resin, FRP and Alumina samples under vacuum condition. In addition, the measurements of secondary electron emission (SEE) characteristics are also reported. These are important parameters to analyze surface discharge characteristics of insulators in vacuum.

High fusion performance at high T i/ T e in JET-ILW baseline plasmas with high NBI heating power and low gas puffing

DOE PAGES

Kim, Hyun-Tae; Sips, A. C. C.; Romanelli, M.; ...

2018-02-01

This article presents the transport analysis of high density baseline discharges in the 2016 experimental campaign of the Joint European Torus with the ITER-Like Wall (JET-ILW), where a significant increase in the deuterium–deuterium (D–D) fusion neutron rate (~2.8 × 10 16 s -1) was achieved with stable high neutral beam injection (NBI) powers of up to 28 MW and low gas puffing. Increase in T i exceeding T e were produced for the first time in baseline discharges despite the high electron density; this enabled a significant increase in the thermal fusion reaction rate. As a result, the new achievedmore » record in fusion performance was much higher than the previous record in the same heating power baseline discharges, where T i = T e. In addition to the decreases in collisionality and the increases in ion heating fraction in the discharges with high NBI power, T i > T e can also be attributed to positive feedback between the high T i/T e ratio and stabilisation of the turbulent heat flux resulting from the ion temperature gradient driven mode. The high T i/T e ratio was correlated with high rotation frequency. Among the discharges with identical beam heating power, higher rotation frequencies were observed when particle fuelling was provided by low gas puffing and pellet injection. Lastly, this reveals that particle fuelling played a key role for achieving high T i/T e, and the improved fusion performance.« less

High fusion performance at high T i/ T e in JET-ILW baseline plasmas with high NBI heating power and low gas puffing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hyun-Tae; Sips, A. C. C.; Romanelli, M.

This article presents the transport analysis of high density baseline discharges in the 2016 experimental campaign of the Joint European Torus with the ITER-Like Wall (JET-ILW), where a significant increase in the deuterium–deuterium (D–D) fusion neutron rate (~2.8 × 10 16 s -1) was achieved with stable high neutral beam injection (NBI) powers of up to 28 MW and low gas puffing. Increase in T i exceeding T e were produced for the first time in baseline discharges despite the high electron density; this enabled a significant increase in the thermal fusion reaction rate. As a result, the new achievedmore » record in fusion performance was much higher than the previous record in the same heating power baseline discharges, where T i = T e. In addition to the decreases in collisionality and the increases in ion heating fraction in the discharges with high NBI power, T i > T e can also be attributed to positive feedback between the high T i/T e ratio and stabilisation of the turbulent heat flux resulting from the ion temperature gradient driven mode. The high T i/T e ratio was correlated with high rotation frequency. Among the discharges with identical beam heating power, higher rotation frequencies were observed when particle fuelling was provided by low gas puffing and pellet injection. Lastly, this reveals that particle fuelling played a key role for achieving high T i/T e, and the improved fusion performance.« less

Measurements of fast ion spatial dynamics during magnetic activity in the RFP

NASA Astrophysics Data System (ADS)

Goetz, J. A.; Anderson, J. K.; Bonofiglo, P.; Kim, J.; McConnell, R.; Magee, R. M.

2017-10-01

Fast ions in the RFP are only weakly affected by a stochastic magnetic field and behave nearly classically in concentration too low to excite Alfvenic activity. At high fast ion concentration sourced by H-NBI in 300kA RFP discharges, a substantial drop in core-localized high pitch fast ions is observed during bursts of coupled EPM and IAE (magnetic island-induced Alfven eigenmode) activity (100-200kHz) through neutral particle analysis. Sourcing instead fast deuterium with NBI, the DD fusion products can measure the dynamics of the fast ion density profile. Both a collimated neutron detector and a new 3MeV fusion proton detector loaned by TriAlpha Energy measure the fast ion density profile with 5cm spatial resolution and 100 μs temporal resolution. In D-NBI, the bursting EPM is excited at slightly lower frequency and the IAE activity is nearly absent, likely due to an isotope effect and loss of wave-particle interaction. In these cases, neutral particle analysis shows little change in the core-localized high pitch fast ion content, and the fusion product profile indicates little change in the fast ion density profile, leaving unexplained the mechanism removing EPM drive. We measure a substantial redistribution of the fast ion profile due to strong lower-frequency ( 30kHz) MHD activity that accompanies the current profile relaxation in the RFP. Profile flattening is strongest in low bulk density discharges, which often occur with a total increase in global neutron flux from acceleration of the beam ions. Work supported by US DoE.

High fusion performance at high T i/T e in JET-ILW baseline plasmas with high NBI heating power and low gas puffing

NASA Astrophysics Data System (ADS)

Kim, Hyun-Tae; Sips, A. C. C.; Romanelli, M.; Challis, C. D.; Rimini, F.; Garzotti, L.; Lerche, E.; Buchanan, J.; Yuan, X.; Kaye, S.; contributors, JET

2018-03-01

This paper presents the transport analysis of high density baseline discharges in the 2016 experimental campaign of the Joint European Torus with the ITER-Like Wall (JET-ILW), where a significant increase in the deuterium-deuterium (D-D) fusion neutron rate (~2.8  ×  1016 s-1) was achieved with stable high neutral beam injection (NBI) powers of up to 28 MW and low gas puffing. Increase in T i exceeding T e were produced for the first time in baseline discharges despite the high electron density; this enabled a significant increase in the thermal fusion reaction rate. As a result, the new achieved record in fusion performance was much higher than the previous record in the same heating power baseline discharges, where T i  =  T e. In addition to the decreases in collisionality and the increases in ion heating fraction in the discharges with high NBI power, T i  >  T e can also be attributed to positive feedback between the high T i/T e ratio and stabilisation of the turbulent heat flux resulting from the ion temperature gradient driven mode. The high T i/T e ratio was correlated with high rotation frequency. Among the discharges with identical beam heating power, higher rotation frequencies were observed when particle fuelling was provided by low gas puffing and pellet injection. This reveals that particle fuelling played a key role for achieving high T i/T e, and the improved fusion performance.

[Clinical and endoscopic features of a selected population with serrated colorectal adenomas in a private clinic in Lima - Peru].

PubMed

Castillo, Ofelia; Barreda, Carlos; Recavarren, Sixto; Barriga, José A; Salazar M, Fernando; Yriberry, Simón; Barriga, Eduardo; Salazar C, Fernando

2013-01-01

To describe the clinical and endoscopic caracteristics of a population that has only serrated polyps of colon (mainly sessile serrated adenomas) in a private clinic in Lima, Perú, from 2009-2011. Retrospective study conducted at the endoscopy center of Clinic Ricardo Palma, Lima, Peru. Olympus colonoscope was used with high definition, including NBI (narrow band imaging) and electronic magnification. Patients had pathologic diagnosis of “polyps and / or colorectal serrated adenomas” and excluded those with synchronous tubular or villous adenomas. Images were evaluated by two endoscopists and then by a third gastroenterologist. We found 201 serrated polyps in 108 patients. Women were 60.2% and overweight predominated. Eighty (74.1%) had only one serrated adenoma and 23 (21.3%) with at least one synchronous hyperplastic polyp. The average size of sessile serrated adenomas was 5.12 mm (± 3.87 DS) and the flat type was 91 (58.7%). There were significant differences in the diameter of sessile serrated adenomas between the distal and proximal colon (4.47 mm ± 2.23 vs. 6.90 mm ± 6.25; p<0.000). The common features of sessile serrated adenomas were: White (31/36, 86.1%), smooth (28/36, 77.8%) and regular margins (26/36, 72.2%). There was a relationship between vascular pattern according NBI and serrated polyp histology (p=0.024). The endoscopic features of sessile serrated adenomas can evade detection to white light. NBI is a useful tool to define some features of these lesions.

Is narrow-band imaging useful for histological evaluation of gastric mucosa-associated lymphoid tissue lymphoma after treatment?

PubMed

Nonaka, Kouichi; Ohata, Ken; Matsuhashi, Nobuyuki; Shimizu, Michio; Arai, Shin; Hiejima, Yoshimitsu; Kita, Hiroto

2014-05-01

Endoscopic diagnosis of stomach mucosa-associated lymphoid tissue (MALT) lymphoma is often difficult because few specific findings are indicated. Even when MALT lymphoma is suspected by endoscopy, it is still difficult to make a definitive diagnosis by biopsy because lymphoma cells sometimes distribute unevenly. We previously reported that a tree-like appearance (TLA) is a characteristic finding of MALT lymphoma by narrow-band imaging (NBI) magnifying endoscopy and it is valuable in the selection of an optimal biopsy site in MALT lymphoma. Here, we study the frequency of TLA and evaluate the relationship between the response to eradication therapy and TLA in MALT lymphoma. We retrospectively examined the clinical background, endoscopic findings, response to eradication therapy, and Helicobacter pylori infection status of 16 patients diagnosed with MALT lymphoma who were referred to our hospital from April 2007 to August 2012. The regimen for eradicationtherapy consisted of rabeprazole, with amoxicillin and clarithromycin, all given for 7 days. TLA was found in 75% (12/16) and H. pylori infection in 75% (12/16) of patients diagnosed with MALT lymphoma by NBI magnifying endoscopy. In all complete regression (CR) patients after eradication treatment, the TLA finding had disappeared (100%); however, in the non-CR patients, TLA remained the same as before the eradication therapy (P=0.002). These results suggest that NBI magnifying endoscopy may be useful not only in the diagnosis but also in the evaluation of the response to eradication therapy of MALT lymphoma of the stomach. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Lipidomics informatics for life-science.

PubMed

Schwudke, D; Shevchenko, A; Hoffmann, N; Ahrends, R

2017-11-10

Lipidomics encompasses analytical approaches that aim to identify and quantify the complete set of lipids, defined as lipidome in a given cell, tissue or organism as well as their interactions with other molecules. The majority of lipidomics workflows is based on mass spectrometry and has been proven as a powerful tool in system biology in concert with other Omics disciplines. Unfortunately, bioinformatics infrastructures for this relatively young discipline are limited only to some specialists. Search engines, quantification algorithms, visualization tools and databases developed by the 'Lipidomics Informatics for Life-Science' (LIFS) partners will be restructured and standardized to provide broad access to these specialized bioinformatics pipelines. There are many medical challenges related to lipid metabolic alterations that will be fostered by capacity building suggested by LIFS. LIFS as member of the 'German Network for Bioinformatics' (de.NBI) node for 'Bioinformatics for Proteomics' (BioInfra.Prot) and will provide access to the described software as well as to tutorials and consulting services via a unified web-portal. Copyright © 2017 Elsevier B.V. All rights reserved.

Advances in boronization on NSTX-Upgrade

DOE PAGES

Skinner, C. H.; Bedoya, F.; Scotti, F.; ...

2017-01-27

Boronization has been effective in reducing plasma impurities and enabling access to higher density, higher confinement plasmas in many magnetic fusion devices. The National Spherical Torus eXperiment, NSTX, has recently undergone a major upgrade to NSTX-U in order to develop the physics basis for a ST-based Fusion Nuclear Science Facility (FNSF) with capability for double the toroidal field, plasma current, and NBI heating power and increased pulse duration from 1–1.5 s to 5–8 s. A new deuterated tri-methyl boron conditioning system was implemented together with a novel surface analysis diagnostic. We report on the spatial distribution of the boron depositionmore » versus discharge pressure, gas injection and electrode location. The oxygen concentration of the plasma facing surface was measured by in-vacuo XPS and increased both with plasma exposure and with exposure to trace residual gases. Furthermore, this increase correlated with the rise of oxygen emission from the plasma.« less

Follicle-Stimulating Hormone Regulates igfbp Gene Expression Directly or via Downstream Effectors to Modulate Igf3 Effects on Zebrafish Spermatogenesis

PubMed Central

Safian, Diego; van der Kant, Henk J. G.; Crespo, Diego; Bogerd, Jan; Schulz, Rüdiger W.

2017-01-01

Previous work showed that pharmacological inactivation of Igf-binding proteins (Igfbps), modulators of Igf activity, resulted in an excessive differentiation of type A undifferentiated (Aund) spermatogonia in zebrafish testis in tissue culture when Fsh was present in the incubation medium. Using this testis tissue culture system, we studied here the regulation of igfbp transcript levels by Fsh and two of its downstream effectors, Igf3 and 11-ketotestosterone (11-KT). We also explored how Fsh-modulated igfbp expression affected spermatogonial proliferation by adding or removing the Igfbp inhibitor NBI-31772 at different times. Fsh (100 ng/mL) decreased the transcript levels of igfbp1a, -3, and -6a after 1 or 3 days, while increasing igfbp2a and -5b expression, but only after 5 days of incubation. Igf3 down-regulated the same igfbp transcripts as Fsh but with a delay of at least 4 days. 11-KT increased the transcripts (igfbp2a and 5b) that were elevated by Fsh and decreased those of igfbp6a, as did Fsh, while 11-KT did not change igfbp1a or -3 transcript levels. To evaluate Igfbps effects on spermatogenesis, we quantified under different conditions the mitotic indices and relative section areas occupied by the different spermatogonial generations (type Aund, type A differentiating (Adiff), or type B (B) spermatogonia). Igf3 (100 ng/mL) increased the area occupied by Adiff and B while decreasing the one for Aund. Interestingly, a concentration of Igf3 that was inactive by itself (25 ng/mL) became active in the presence of the Igfbp inhibitor NBI-31772 and mimicked the effect of 100 ng/mL Igf3 on spermatogonia. Studies exploiting the different dynamics of igfbp expression in response to Fsh and adding or removing NBI-31772 at different times showed that the quick downregulation of three igfbp as well as the delayed upregulated of two igfbps all support Igf3 bioactivity, namely the stimulation of spermatogonial differentiation. We conclude that Fsh modulates, directly or via androgens and Igf3, igfbp gene expression, supporting Igf3 bioactivity either by decreasing igfbp1a, -3, -6a or by increasing igfbp2a and -5b gene expression. PMID:29209278

A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor

PubMed Central

Kameoka, Shinichi; Isoda, Shuhei; Hashimoto, Atsushi; Ito, Ryoei; Miyamoto, Satoru; Wada, Genki; Watanabe, Naoki; Yamakami, Takashi; Suzuki, Ken; Kameoka, Takaharu

2017-01-01

We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth. PMID:28448452

A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor.

PubMed

Kameoka, Shinichi; Isoda, Shuhei; Hashimoto, Atsushi; Ito, Ryoei; Miyamoto, Satoru; Wada, Genki; Watanabe, Naoki; Yamakami, Takashi; Suzuki, Ken; Kameoka, Takaharu

2017-04-27

We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth.

Development and validation of the SIMPLE endoscopic classification of diminutive and small colorectal polyps.

PubMed

Iacucci, Marietta; Trovato, Cristina; Daperno, Marco; Akinola, Oluseyi; Greenwald, David; Gross, Seth A; Hoffman, Arthur; Lee, Jeffrey; Lethebe, Brendan C; Lowerison, Mark; Nayor, Jennifer; Neumann, Helmut; Rath, Timo; Sanduleanu, Silvia; Sharma, Prateek; Kiesslich, Ralf; Ghosh, Subrata; Saltzman, John R

2018-03-23

Prediction of histology of small polyps facilitates colonoscopic treatment. The aims of this study were: 1) to develop a simplified polyp classification, 2) to evaluate its performance in predicting polyp histology, and 3) to evaluate the reproducibility of the classification by trainees using multiplatform endoscopic systems. In phase 1, a new simplified endoscopic classification for polyps - Simplified Identification Method for Polyp Labeling during Endoscopy (SIMPLE) - was created, using the new I-SCAN OE system (Pentax, Tokyo, Japan), by eight international experts. In phase 2, the accuracy, level of confidence, and interobserver agreement to predict polyp histology before and after training, and univariable/multivariable analysis of the endoscopic features, were performed. In phase 3, the reproducibility of SIMPLE by trainees using different endoscopy platforms was evaluated. Using the SIMPLE classification, the accuracy of experts in predicting polyps was 83 % (95 % confidence interval [CI] 77 % - 88 %) before and 94 % (95 %CI 89 % - 97 %) after training ( P   = 0.002). The sensitivity, specificity, positive predictive value, and negative predictive value after training were 97 %, 88 %, 95 %, and 91 %. The interobserver agreement of polyp diagnosis improved from 0.46 (95 %CI 0.30 - 0.64) before to 0.66 (95 %CI 0.48 - 0.82) after training. The trainees demonstrated that the SIMPLE classification is applicable across endoscopy platforms, with similar post-training accuracies for narrow-band imaging NBI classification (0.69; 95 %CI 0.64 - 0.73) and SIMPLE (0.71; 95 %CI 0.67 - 0.75). Using the I-SCAN OE system, the new SIMPLE classification demonstrated a high degree of accuracy for adenoma diagnosis, meeting the ASGE PIVI recommendations. We demonstrated that SIMPLE may be used with either I-SCAN OE or NBI. © Georg Thieme Verlag KG Stuttgart · New York.

Automatic classification of endoscopic images for premalignant conditions of the esophagus

NASA Astrophysics Data System (ADS)

Boschetto, Davide; Gambaretto, Gloria; Grisan, Enrico

2016-03-01

Barrett's esophagus (BE) is a precancerous complication of gastroesophageal reflux disease in which normal stratified squamous epithelium lining the esophagus is replaced by intestinal metaplastic columnar epithelium. Repeated endoscopies and multiple biopsies are often necessary to establish the presence of intestinal metaplasia. Narrow Band Imaging (NBI) is an imaging technique commonly used with endoscopies that enhances the contrast of vascular pattern on the mucosa. We present a computer-based method for the automatic normal/metaplastic classification of endoscopic NBI images. Superpixel segmentation is used to identify and cluster pixels belonging to uniform regions. From each uniform clustered region of pixels, eight features maximizing differences among normal and metaplastic epithelium are extracted for the classification step. For each superpixel, the three mean intensities of each color channel are firstly selected as features. Three added features are the mean intensities for each superpixel after separately applying to the red-channel image three different morphological filters (top-hat filtering, entropy filtering and range filtering). The last two features require the computation of the Grey-Level Co-Occurrence Matrix (GLCM), and are reflective of the contrast and the homogeneity of each superpixel. The classification step is performed using an ensemble of 50 classification trees, with a 10-fold cross-validation scheme by training the classifier at each step on a random 70% of the images and testing on the remaining 30% of the dataset. Sensitivity and Specificity are respectively of 79.2% and 87.3%, with an overall accuracy of 83.9%.

Chronic pain management in the active-duty military

NASA Astrophysics Data System (ADS)

Jamison, David; Cohen, Steven P.

2012-06-01

As in the general population, chronic pain is a prevalent and burdensome affliction in active-duty military personnel. Painful conditions in military members can be categorized broadly in terms of whether they arise directly from combat injuries (gunshot, fragmentation wound, blast impact) or whether they result from non-combat injuries (sprains, herniated discs, motor vehicle accidents). Both combat-related and non-combat-related causes of pain can further be classified as either acute or chronic. Here we discuss the state of pain management as it relates to the military population in both deployed and non-deployed settings. The term non-battle injury (NBI) is commonly used to refer to those conditions not directly associated with the combat actions of war. In the history of warfare, NBI have far outstripped battle-related injuries in terms not only of morbidity, but also mortality. It was not until improvements in health care and field medicine were applied in World War I that battle-related deaths finally outnumbered those attributed to disease and pestilence. However, NBI have been the leading cause of morbidity and hospital admission in every major conflict since the Korean War. Pain remains a leading cause of presentation to military medical facilities, both in and out of theater. The absence of pain services is associated with a low return-to-duty rate among the deployed population. The most common pain complaints involve the low-back and neck, and studies have suggested that earlier treatment is associated with more significant improvement and a higher return to duty rate. It is recognized that military medicine is often at the forefront of medical innovation, and that many fields of medicine have reaped benefit from the conduct of war.

Magnifying narrow-band imaging of gastric mucosal morphology predicts the H. pylori-related epigenetic field defect.

PubMed

Tahara, Tomomitsu; Yamazaki, Jumpei; Tahara, Sayumi; Okubo, Masaaki; Kawamura, Tomohiko; Horiguchi, Noriyuki; Ishizuka, Takamitsu; Nagasaka, Mitsuo; Nakagawa, Yoshihito; Shibata, Tomoyuki; Kuroda, Makoto; Ohmiya, Naoki

2017-06-08

DNA methylation is associated with "field defect" in the gastric mucosa. To characterize "field defect" morphologically, we examined DNA methylation of non-neoplastic gastric mucosa in relation to their morphology seen by narrow-band imaging (NBI) with magnifying endoscopy. Magnifying NBI of non-neoplastic gastric body was classified as follows: normal-small and round pits with uniform subepithelial capillary networks; type 1-a little enlarged round pits with indistinct subepithelial capillary networks; type 2-remarkably enlarged pits with irregular vessels; and type 3-clearly demarcated oval or tubulovillous pits with bulky coiled or wavy vessels. Methylation of nine candidate genes (MYOD1, SLC16A12, GDNF, IGF2, MIR 124A1, CDH1, PRDM5, RORA and MLF1) were determined by bisulfite pyrosequencing. Infinium HumanMethylation450 array was used to characterize the methylation of >450,000 CpG sites. Mean Z score methylation of nine genes positively correlated with the changes of mucosal patterns from normal to types 1, 2, and 3 (P < 0.0001). Genome-wide analysis showed that development of mucosal patterns correlated with methylation accumulation especially at CpG islands. Genes with promoter CpG islands that were gradually methylated with the development of mucosal patterns significantly enriched the genes involved in zinc-related pathways. The results indicates that gastric mucosal morphology predicts a "field defect" in this tissue type. Accumulation of DNA methylation is associated with "field defect" in the non-neoplastic gastric mucosa. Endoscopic identification of "field defect" has important implications for preventing gastric cancer. Our results suggest that magnifying NBI of gastric mucosal morphology predicts a "field defect" in the gastric mucosa.

Advanced Fuels Reactor using Aneutronic Rodless Ultra Low Aspect Ratio Tokamak Hydrogenic Plasmas

NASA Astrophysics Data System (ADS)

Ribeiro, Celso

2015-11-01

The use of advanced fuels for fusion reactor is conventionally envisaged for field reversed configuration (FRC) devices. It is proposed here a preliminary study about the use of these fuels but on an aneutronic Rodless Ultra Low Aspect Ratio (RULART) hydrogenic plasmas. The idea is to inject micro-size boron pellets vertically at the inboard side (HFS, where TF is very high and the tokamak electron temperature is relatively low because of profile), synchronised with a proton NBI pointed to this region. Therefore, p-B reactions should occur and alpha particles produced. These pellets will act as an edge-like disturbance only (cp. killer pellet, although the vertical HFS should make this less critical, since the unablated part should appear in the bottom of the device). The boron cloud will appear at midplance, possibly as a MARFE-look like. Scaling of the p-B reactions by varying the NBI energy should be compared with the predictions of nuclear physics. This could be an alternative to the FRC approach, without the difficulties of the optimization of the FRC low confinement time. Instead, a robust good tokamak confinement with high local HFS TF (enhanced due to the ultra low aspect ratio and low pitch angle) is used. The plasma central post makes the RULART concept attractive because of the proximity of NBI path and also because a fraction of born alphas will cross the plasma post and dragged into it in the direction of the central plasma post current, escaping vertically into a hole in the bias plate and reaching the direct electricity converter, such as in the FRC concept.

Detection of palisade vessels as a landmark for Barrett's esophagus in a Western population.

PubMed

Schölvinck, Dirk W; Goto, Osamu; Seldenrijk, Cornelis A; Bisschops, Raf; Horii, Joichiro; Ochiai, Yasutoshi; Schoon, Erik J; Schenk, Boudewijn E; Uraoka, Toshio; van Oijen, Martijn G H; Bergman, Jacques J G H M; Yahagi, Naohisa; Weusten, Bas L A M

2016-07-01

In Japan, palisade vessels (PV) are used to distinguish the esophagogastric junction (EGJ). Elsewhere, the EGJ is defined by the upper end of the gastric folds (GF) and PV are considered difficult to detect. This study evaluated the detection rate of PV in Western patients with Barrett's esophagus (BE) using white light imaging (WLI) and narrow band imaging (NBI), and quantified any discordance between Western and Japanese criteria for the EGJ. In 25 BE patients, the presence and location of PV and GF were determined and biopsies were obtained. High-quality images of the EGJ were collected under different conditions (insufflations-desufflation, WLI-NBI, forward-retroflex approach), resulting in eight different images per patient. The presence of PV on each still image was assessed by a panel of six Western and Japanese endoscopists with expertise in BE. PV were observed in ≥ 1 images by a majority of the panel (≥ 4 raters) in 100 % of patients during insufflation versus 60 % during desufflation (p < 0.001). WLI and NBI detected PV in 100 and 92 %, respectively (p = 0.50). Interobserver agreement of the panel was 'moderate' (κ = 0.51). During endoscopy PV were located a median of 1 cm distal of the GF in 15 patients (63 %), with intestinal metaplasia (IM) in this discordant zone, in 27 % of patients. PV are visible in most Western BE patients and are best inspected during insufflation. The location of the GF and PV differed in a substantial group of patients, partially with IM in this discordant zone.

Surface discharge related properties of fiberglass reinforced plastic insulator for use in neutral beam injector of JT-60U.

PubMed

Yamano, Y; Takahashi, M; Kobayashi, S; Hanada, M; Ikeda, Y

2008-02-01

Neutral beam injection (NBI) used for JT-60U is required to generate negative ions of 500 keV energies. To produce such high-energy ions, three-stage electrostatic accelerators consisting of three insulator rings made of fiberglass reinforced plastic (FRP) are applied. The surface discharges along FRP insulators are one of the most serious problems in the development of NBI. To increase the hold-off voltage against surface flashover events, it is necessary to investigate the FRP insulator properties related to surface discharges in vacuum. This paper describes surface flashover characteristics for FRP and alumina samples under vacuum condition. The results show that the fold-off voltages for FRP samples are inferior to those of alumina ceramics. In addition, measurement results of surface resistivity and volume resistivity under vacuum and atmospheric conditions, secondary electron emission characteristics, and cathodoluminescence under some keV electron beam irradiation are also reported. These are important parameters to analyze surface discharge of insulators in vacuum.

Surface discharge related properties of fiberglass reinforced plastic insulator for use in neutral beam injector of JT-60Ua)

NASA Astrophysics Data System (ADS)

Yamano, Y.; Takahashi, M.; Kobayashi, S.; Hanada, M.; Ikeda, Y.

2008-02-01

Neutral beam injection (NBI) used for JT-60U is required to generate negative ions of 500keV energies. To produce such high-energy ions, three-stage electrostatic accelerators consisting of three insulator rings made of fiberglass reinforced plastic (FRP) are applied. The surface discharges along FRP insulators are one of the most serious problems in the development of NBI. To increase the hold-off voltage against surface flashover events, it is necessary to investigate the FRP insulator properties related to surface discharges in vacuum. This paper describes surface flashover characteristics for FRP and alumina samples under vacuum condition. The results show that the fold-off voltages for FRP samples are inferior to those of alumina ceramics. In addition, measurement results of surface resistivity and volume resistivity under vacuum and atmospheric conditions, secondary electron emission characteristics, and cathodoluminescence under some keV electron beam irradiation are also reported. These are important parameters to analyze surface discharge of insulators in vacuum.

Swarm intelligence for multi-objective optimization of synthesis gas production

NASA Astrophysics Data System (ADS)

Ganesan, T.; Vasant, P.; Elamvazuthi, I.; Ku Shaari, Ku Zilati

2012-11-01

In the chemical industry, the production of methanol, ammonia, hydrogen and higher hydrocarbons require synthesis gas (or syn gas). The main three syn gas production methods are carbon dioxide reforming (CRM), steam reforming (SRM) and partial-oxidation of methane (POM). In this work, multi-objective (MO) optimization of the combined CRM and POM was carried out. The empirical model and the MO problem formulation for this combined process were obtained from previous works. The central objectives considered in this problem are methane conversion, carbon monoxide selectivity and the hydrogen to carbon monoxide ratio. The MO nature of the problem was tackled using the Normal Boundary Intersection (NBI) method. Two techniques (Gravitational Search Algorithm (GSA) and Particle Swarm Optimization (PSO)) were then applied in conjunction with the NBI method. The performance of the two algorithms and the quality of the solutions were gauged by using two performance metrics. Comparative studies and results analysis were then carried out on the optimization results.

Electrostatic sensors for SPIDER experiment: Design, manufacture of prototypes, and first tests

NASA Astrophysics Data System (ADS)

Brombin, M.; Spolaore, M.; Serianni, G.; Barzon, A.; Franchin, L.; Pasqualotto, R.; Pomaro, N.; Schiesko, L.; Taliercio, C.; Trevisan, L.

2014-02-01

A system of electrostatic sensors has been designed for the SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) experiment, prototype RF source of the ITER NBI (neutral beam injection). A prototype of the sensor system was manufactured and tested at the BATMAN (BAvarian Test MAchine for Negative ions) facility, where the plasma environment is similar to that of SPIDER. Different aspects concerning the mechanical manufacturing and the signal conditioning are presented, among them the RF compensation adopted to reduce the RF effects which could lead to overestimated values of the electron temperature. The first commissioning tests provided ion saturation current values in the range assumed for the design, so the deduced plasma density estimate is consistent with the expected values.

Electrostatic sensors for SPIDER experiment: design, manufacture of prototypes, and first tests.

PubMed

Brombin, M; Spolaore, M; Serianni, G; Barzon, A; Franchin, L; Pasqualotto, R; Pomaro, N; Schiesko, L; Taliercio, C; Trevisan, L

2014-02-01

A system of electrostatic sensors has been designed for the SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) experiment, prototype RF source of the ITER NBI (neutral beam injection). A prototype of the sensor system was manufactured and tested at the BATMAN (BAvarian Test MAchine for Negative ions) facility, where the plasma environment is similar to that of SPIDER. Different aspects concerning the mechanical manufacturing and the signal conditioning are presented, among them the RF compensation adopted to reduce the RF effects which could lead to overestimated values of the electron temperature. The first commissioning tests provided ion saturation current values in the range assumed for the design, so the deduced plasma density estimate is consistent with the expected values.

Electrostatic sensors for SPIDER experiment: Design, manufacture of prototypes, and first tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brombin, M., E-mail: matteo.brombin@igi.cnr.it; Spolaore, M.; Serianni, G.

2014-02-15

A system of electrostatic sensors has been designed for the SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) experiment, prototype RF source of the ITER NBI (neutral beam injection). A prototype of the sensor system was manufactured and tested at the BATMAN (BAvarian Test MAchine for Negative ions) facility, where the plasma environment is similar to that of SPIDER. Different aspects concerning the mechanical manufacturing and the signal conditioning are presented, among them the RF compensation adopted to reduce the RF effects which could lead to overestimated values of the electron temperature. The first commissioningmore » tests provided ion saturation current values in the range assumed for the design, so the deduced plasma density estimate is consistent with the expected values.« less

Combined magnetic and kinetic control of advanced tokamak steady state scenarios based on semi-empirical modelling

DOE PAGES

Moreau, Didier; Artaud, J. F.; Ferron, John R.; ...

2015-05-01

This paper shows that semi-empirical data-driven models based on a twotime- scale approximation for the magnetic and kinetic control of advanced tokamak (AT) scenarios can be advantageously identified from simulated rather than real data, and used for control design. The method is applied to the combined control of the safety factor profile, q(x), and normalized pressure parameter, β N, using DIII-D parameters and actuators (on-axis co-current neutral beam injection (NBI) power, off axis co-current NBI power, electron cyclotron current drive power, and ohmic coil). The approximate plasma response model was identified from simulated data obtained using a rapidly converging plasmamore » transport code, METIS, which includes an MHD equilibrium and current diffusion solver, and combines plasma transport nonlinearity with 0-D scaling laws and 1.5-D ordinary differential equations. A number of open loop simulations were performed, in which the heating and current drive (H&CD) sources were randomly modulated around the typical values of a reference AT discharge on DIIID. Using these simulated data, a two-time-scale state space model was obtained for the coupled evolution of the poloidal flux profile and βN parameter, and a controller was synthesized based on the near-optimal ARTAEMIS algorithm [D. Moreau et al., Nucl. Fusion 53 (2013) 063020]. The paper discusses the results of closed-loop nonlinear simulations, using this controller for steady state AT operation. With feedforward plus feedback control, the steady state target q-profile and β N are satisfactorily tracked with a time scale of about ten seconds, despite large disturbances applied to the feedforward powers and plasma parameters. The effectiveness of the control algorithm is thus demonstrated for long pulse and steady state high-β N AT discharges. Its robustness with respect to disturbances of the H&CD actuators and of plasma parameters such as the H-factor, plasma density and effective charge, is also shown.« less

Integrated biophotonics in endoscopic oncology

NASA Astrophysics Data System (ADS)

Muguruma, Naoki; DaCosta, Ralph S.; Wilson, Brian C.; Marcon, Norman E.

2009-02-01

Gastrointestinal endoscopy has made great progress during last decade. Diagnostic accuracy can be enhanced by better training, improved dye-contrast techniques method, and the development of new image processing technologies. However, diagnosis using conventional endoscopy with white-light optical imaging is essentially limited by being based on morphological changes and/or visual attribution: hue, saturation and intensity, interpretation of which depends on the endoscopist's eye and brain. In microlesions in the gastrointestinal tract, we still rely ultimately on the histopathological diagnosis from biopsy specimens. Autofluorescence imaging system has been applied for lesions which have been difficult to morphologically recognize or are indistinct with conventional endoscope, and this approach has potential application for the diagnosis of dysplastic lesions and early cancers in the gastrointestinal tract, supplementing the information from white light endoscopy. This system has an advantage that it needs no administration of a photosensitive agent, making it suitable as a screening method for the early detection of neoplastic tissues. Narrow band imaging (NBI) is a novel endoscopic technique which can distinguish neoplastic and non-neoplastic lesions without chromoendoscopy. Magnifying endoscopy in combination with NBI has an obvious advantage, namely analysis of the epithelial pit pattern and the vascular network. This new technique allows a detailed visualization in early neoplastic lesions of esophagus, stomach and colon. However, problems remain; how to combine these technologies in an optimum diagnostic strategy, how to apply them into the algorithm for therapeutic decision-making, and how to standardize several classifications surrounding them. 'Molecular imaging' is a concept representing the most novel imaging methods in medicine, although the definition of the word is still controversial. In the field of gastrointestinal endoscopy, the future of endoscopic diagnosis is likely to be impacted by a combination of biomarkers and technology, and 'endoscopic molecular imaging' should be defined as "visualization of molecular characteristics with endoscopy". These innovations will allow us not only to locate a tumor or dysplastic lesion but also to visualize its molecular characteristics (e.g., DNA mutations and polymorphisms, gene and/or protein expression), and the activity of specific molecules and biological processes that affect tumor behavior and/or its response to therapy. In the near future, these methods should be promising technologies that will play a central role in gastrointestinal oncology.

R&D around a photoneutralizer-based NBI system (Siphore) in view of a DEMO Tokamak steady state fusion reactor

NASA Astrophysics Data System (ADS)

Simonin, A.; Achard, Jocelyn; Achkasov, K.; Bechu, S.; Baudouin, C.; Baulaigue, O.; Blondel, C.; Boeuf, J. P.; Bresteau, D.; Cartry, G.; Chaibi, W.; Drag, C.; de Esch, H. P. L.; Fiorucci, D.; Fubiani, G.; Furno, I.; Futtersack, R.; Garibaldi, P.; Gicquel, A.; Grand, C.; Guittienne, Ph.; Hagelaar, G.; Howling, A.; Jacquier, R.; Kirkpatrick, M. J.; Lemoine, D.; Lepetit, B.; Minea, T.; Odic, E.; Revel, A.; Soliman, B. A.; Teste, P.

2015-11-01

Since the signature of the ITER treaty in 2006, a new research programme targeting the emergence of a new generation of neutral beam (NB) system for the future fusion reactor (DEMO Tokamak) has been underway between several laboratories in Europe. The specifications required to operate a NB system on DEMO are very demanding: the system has to provide plasma heating, current drive and plasma control at a very high level of power (up to 150 MW) and energy (1 or 2 MeV), including high performances in term of wall-plug efficiency (η  >  60%), high availability and reliability. To this aim, a novel NB concept based on the photodetachment of the energetic negative ion beam is under study. The keystone of this new concept is the achievement of a photoneutralizer where a high power photon flux (~3 MW) generated within a Fabry-Perot cavity will overlap, cross and partially photodetach the intense negative ion beam accelerated at high energy (1 or 2 MeV). The aspect ratio of the beam-line (source, accelerator, etc) is specifically designed to maximize the overlap of the photon beam with the ion beam. It is shown that such a photoneutralized based NB system would have the capability to provide several tens of MW of D0 per beam line with a wall-plug efficiency higher than 60%. A feasibility study of the concept has been launched between different laboratories to address the different physics aspects, i.e. negative ion source, plasma modelling, ion accelerator simulation, photoneutralization and high voltage holding under vacuum. The paper describes the present status of the project and the main achievements of the developments in laboratories.

Novel laparoscopic narrow band imaging for real-time detection of bile leak during hepatectomy: proof of the concept in a porcine model.

PubMed

Diana, Michele; Usmaan, Hameed; Legnèr, Andras; Yu-Yin, Liu; D'Urso, Antonio; Halvax, Peter; Nagao, Yoshihiro; Pessaux, Patrick; Marescaux, Jacques

2016-07-01

Bile leakage is a serious complication occurring in up to 10 % of hepatic resections. Intraoperative detection of bile leakage is challenging, and concomitant blood oozing can mask the presence of bile. Intraductal dye injection [methylene blue or indocyanine green (ICG)] is a validated technique to detect bile leakage. However, this method is time-consuming, particularly in the laparoscopic setting. A novel narrow band imaging (NBI) modality (SPECTRA-A; Karl Storz, Tuttlingen, Germany) allows easy discrimination of the presence of bile, which appears in clear orange, by image processing. The aim of this experimental study was to evaluate SPECTRA-A ability to detect bile leakage. Twelve laparoscopic partial hepatectomies were performed in seven pigs. The common bile duct was clipped distally and dissected, and a catheter was inserted and secured with a suture or a clip. Liver dissection was achieved with an ultrasonic cutting device. Dissection surfaces were checked by frequently switching on the SPECTRA filter to identify the presence of bile leakage. Intraductal ICG injection through the catheter was performed to confirm SPECTRA findings. Three active bile leakages were obtained out of 12 hepatectomies and successfully detected intraoperatively by the SPECTRA. There was complete concordance between NBI and ICG fluorescence detection. No active leaks were found in the remaining cases with both techniques. The leaking area identified was sutured, and SPECTRA was used to assess the success of the repair. The SPECTRA laparoscopic image processing system allows for rapid detection of bile leaks following hepatectomy without any contrast injection.

Feedback Control of Resistive Wall Modes in Slowly Rotating DIII-D Plasmas

NASA Astrophysics Data System (ADS)

Okabayashi, M.; Chance, M. S.; Takahashi, H.; Garofalo, A. M.; Reimerdes, H.; in, Y.; Chu, M. S.; Jackson, G. L.; La Haye, R. J.; Strait, E. J.

2006-10-01

In slowly rotating plasmas on DIII-D, the requirement of RWM control feedback have been identified, using a MHD code along with measured power supply characteristics. It was found that a small time delay is essential for achieving high beta if no rotation stabilization exists. The overall system delay or the band pass time constant should be in the range of 0.4 of the RWM growth time. Recently the control system was upgraded using twelve linear audio amplifiers and a faster digital control system, reducing the time-delay from 600 to 100 μs. The advantage has been clearly observed when the RWMs excited by ELMs were effectively controlled by feedback even if the rotation transiently slowed nearly to zero. This study provides insight on stability in the low- rotation plasmasw with balanced NBI in DIII-D and also in ITER.

Sustained high βN plasmas on EAST tokamak

NASA Astrophysics Data System (ADS)

Gao, Xiang; the EAST team

2018-05-01

Sustained high normalized beta (βN ∼ 1.9) plasmas with an ITER-like tungsten divertor have been achieved on EAST tokamak recently. The high power NBI heating system of 4.8 MW and the 4.6 GHz lower hybrid wave of 1 MW were developed and applied to produce edge and internal transport barriers in high βN discharges. The central flat q profile with q (ρ) ∼ 1 at ρ < 0.3 region and edge safety factor q95 = 4.7 is identified by the multi-channel far-infrared laser polarimeter and the EFIT code. The fraction of non-inductive current is about 40%. The relation between fishbone activity and ITB formation is observed and discussed.

Role of new endoscopic techniques in inflammatory bowel disease management: Has the change come?

PubMed

Goran, Loredana; Negreanu, Lucian; Negreanu, Ana Maria

2017-06-28

Despite significant therapeutic progress in recent years, inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, remains a challenge regarding its pathogenesis and long-term complications. New concepts have emerged in the management of this disease, such as the "treat-to-target" concept, in which mucosal healing plays a key role in the evolution of IBD, the risk of recurrence and the need for surgery. Endoscopy is essential for the assessment of mucosal inflammation and plays a pivotal role in the analysis of mucosal healing in patients with IBD. Endoscopy is also essential in the detection of dysplasia and in the identification of the risk of colon cancer. The current surveillance strategy for dysplasia in IBD patients indicates white-light endoscopy with non-targeted biopsies. The new chromoendoscopy techniques provide substantial benefits for both clinicians and patients. Narrow-band imaging (NBI) has similar rates of dysplastic lesion detection as white-light endoscopy, and it seems that NBI identifies more adenoma-like lesions. Because it is used instinctively by many endoscopists, the combination of these two techniques might improve the rate of dysplasia detection. Flexible spectral imaging color enhancement can help differentiate dysplastic and non-dysplastic lesions and can also predict the risk of recurrence, which allows us to modulate the treatment to gain better control of the disease. The combination of non-invasive serum and stool biomarkers with endoscopy will improve the monitoring and limit the evolution of IBD because it enables the use of a personalized approach to each patient based on that patient's history and risk factors.

Thermoelectric properties, Shubnikov-de Haas effect and mobility of charge carriers in bismuth antimony tellurides and selenides and nanocomposite based on these materials

NASA Astrophysics Data System (ADS)

Kulbachinskii, V. A.; Kytin, V. G.; Kudryashov, A. A.; Lunin, R. A.; Banerjee, A.

2017-04-01

We describe here the study of the Shubnikov-de Haas effect and thermoelectric properties of p-(Bi0.5Sb0.5)2Te3 single crystals doped with Ga, n-Bi2-xTlxSe3 and p-Sb2-xTlxTe3. Using Fourier spectra of the oscillations we calculated the mobility of charge carriers and its variation upon doping. We found that Ga has a donor effect in p-(Bi0.5Sb0.5)2Te3, Tl is an acceptor in n-Bi2-xTlxSe3 and increases the mobility of electrons, while in p-Sb2-xTlxTe3, Tl is a donor and decreases the mobility of holes. We consider the evolution of the defectiveness of crystals that leads to the observed effects. We also synthesized and investigated nanocomposites of solid solutions Sb2Te3-xSex (0 < x < 1). When Se concentration increases in Sb2Te3-xSex, the concentration of holes decreases. At the same time the Seebeck coefficient decreases. This is not typical for semiconductors but correlates with the earlier data. A theoretical model was developed to calculate simultaneously the dependences of the Seebeck coefficient, Hall coefficient and conductivity on the selenium concentration x. Calculations showed that for a simultaneous quantitative description of the thermoelectric and galvanomagnetic data it is necessary to take into consideration both the evolution of the band structure of Sb2Te3-xSex and partial localization of holes.

Risk Factors Analysis and Death Prediction in Some Life-Threatening Ailments Using Chi-Square Case-Based Reasoning (χ2 CBR) Model.

PubMed

Adeniyi, D A; Wei, Z; Yang, Y

2018-01-30

A wealth of data are available within the health care system, however, effective analysis tools for exploring the hidden patterns in these datasets are lacking. To alleviate this limitation, this paper proposes a simple but promising hybrid predictive model by suitably combining the Chi-square distance measurement with case-based reasoning technique. The study presents the realization of an automated risk calculator and death prediction in some life-threatening ailments using Chi-square case-based reasoning (χ 2 CBR) model. The proposed predictive engine is capable of reducing runtime and speeds up execution process through the use of critical χ 2 distribution value. This work also showcases the development of a novel feature selection method referred to as frequent item based rule (FIBR) method. This FIBR method is used for selecting the best feature for the proposed χ 2 CBR model at the preprocessing stage of the predictive procedures. The implementation of the proposed risk calculator is achieved through the use of an in-house developed PHP program experimented with XAMP/Apache HTTP server as hosting server. The process of data acquisition and case-based development is implemented using the MySQL application. Performance comparison between our system, the NBY, the ED-KNN, the ANN, the SVM, the Random Forest and the traditional CBR techniques shows that the quality of predictions produced by our system outperformed the baseline methods studied. The result of our experiment shows that the precision rate and predictive quality of our system in most cases are equal to or greater than 70%. Our result also shows that the proposed system executes faster than the baseline methods studied. Therefore, the proposed risk calculator is capable of providing useful, consistent, faster, accurate and efficient risk level prediction to both the patients and the physicians at any time, online and on a real-time basis.

Design of a Lossless Image Compression System for Video Capsule Endoscopy and Its Performance in In-Vivo Trials

PubMed Central

Khan, Tareq H.; Wahid, Khan A.

2014-01-01

In this paper, a new low complexity and lossless image compression system for capsule endoscopy (CE) is presented. The compressor consists of a low-cost YEF color space converter and variable-length predictive with a combination of Golomb-Rice and unary encoding. All these components have been heavily optimized for low-power and low-cost and lossless in nature. As a result, the entire compression system does not incur any loss of image information. Unlike transform based algorithms, the compressor can be interfaced with commercial image sensors which send pixel data in raster-scan fashion that eliminates the need of having large buffer memory. The compression algorithm is capable to work with white light imaging (WLI) and narrow band imaging (NBI) with average compression ratio of 78% and 84% respectively. Finally, a complete capsule endoscopy system is developed on a single, low-power, 65-nm field programmable gate arrays (FPGA) chip. The prototype is developed using circular PCBs having a diameter of 16 mm. Several in-vivo and ex-vivo trials using pig's intestine have been conducted using the prototype to validate the performance of the proposed lossless compression algorithm. The results show that, compared with all other existing works, the proposed algorithm offers a solution to wireless capsule endoscopy with lossless and yet acceptable level of compression. PMID:25375753

MAST Upgrade Status and Future Enhancements

NASA Astrophysics Data System (ADS)

Harrison, James; MAST Upgrade Team Team

2017-10-01

The MAST Upgrade spherical tokamak has unique capabilities to address some of the key issues facing the development of fusion energy. Its main objectives are: 1) development of novel exhaust concepts, 2) contribution to the knowledge base for ITER and 3) to explore potential routes to smaller/cheaper fusion reactors. To fulfil these aims, it is equipped with 19 new poloidal field coils and closed divertors with Super-X capability. BT has been increased by 50% and the pulse length and Ip have increased to 5s and 2MA respectively. Auxiliary heating is provided by on and off axis NBI. The gas fuelling system allows for injection from 10 poloidal locations. The divertors are diagnosed with probes, bolometers, Thomson scattering, IR, visible imaging and spectroscopy. Fast ion physics studies are enhanced with a new fast ion loss detector. Following the construction phase, further enhancements are underway including new diagnostics, a cryoplant to serve the cryopumps and 2 additional neutral beams to increase the heating power from 5 to 10MW. Work supported by the RCUK Energy Programme [Grant Number EP/P012450/1] and EURATOM.

Plasma Rotation During Neutral Beam Injection In MST

NASA Astrophysics Data System (ADS)

Hudson, Ben; Ding, W.; Fiksel, G.; Prager, S.; Yates, T.

2006-10-01

The effect of fast ions from neutral beam injection (20 keV, 30 A, 1.5 ms) on plasma rotation and magnetic tearing modes is studied. We observe that during co-injected NBI (with the injection in the same direction as the plasma and mode rotation) the rotation of the core-resonant n = 5 magnetic mode decreases and in many instances lock to the vessel wall. There is an associated drop in the poloidal component of n = 5 magnetic mode amplitude. The drop in the mode velocity suggests a counter-directed torque, perhaps due to modification of the radial electric field. The rotation slows during the injection phase, then restores itself on the timescale of the fast ion slowing down time (5 ms @ Te = 100 eV). The fluctuation-induced j x b Maxwell stress is measured using MST's FIR diagnostic and presented for comparison. Equilibrium reconstruction suggests a small increase in on-axis J||, consistent with the presence of a localized fast ion population moving in the direction of the plasma current. Mode rotation during NBI counter-injection is also presented.

Time Dependent Predictive Modeling of DIII-D ITER Baseline Scenario using Predictive TRANSP

NASA Astrophysics Data System (ADS)

Grierson, B. A.; Andre, R. G.; Budny, R. V.; Solomon, W. M.; Yuan, X.; Candy, J.; Pinsker, R. I.; Staebler, G. M.; Holland, C.; Rafiq, T.

2015-11-01

ITER baseline scenario discharges on DIII-D are modeled with TGLF and MMM transitioning from combined ECH (3.3MW) +NBI(2.8MW) heating to NBI only (3.0 MW) heating maintaining βN = 2.0 on DIII-D predicting temperature, density and rotation for comparison to experimental measurements. These models capture the reduction of confinement associated with direct electron heating H98y2 = 0.89 vs. 1.0) consistent with stiff electron transport. Reasonable agreement between experimental and modeled temperature profiles is achieved for both heating methods, whereas density and momentum predictions differ significantly. Transport fluxes from TGLF indicate that on DIII-D the electron energy flux has reached a transition from low-k to high-k turbulence with more stiff high-k transport that inhibits an increase in core electron stored energy with additional electron heating. Projections to ITER also indicate high electron stiffness. Supported by US DOE DE-AC02-09CH11466, DE-FC02-04ER54698, DE-FG02-07ER54917, DE-FG02-92-ER54141.

Enhanced motivation for food reward induced by stress and attenuation by corticotrophin-releasing factor receptor antagonism in rats: implications for overeating and obesity

PubMed Central

Liu, Xiu

2014-01-01

Rationale Overeating beyond individuals’ homeostatic needs critically contributes to obesity. The neurobehavioral mechanisms underlying the motivation to consume excessive foods with high calories are not fully understood. Objective The present study examined whether a pharmacological stressor, yohimbine enhances the motivation to procure food reward with an emphasis on comparisons between standard lab chow and high-fat foods. The effects of corticotropin-releasing factor receptor (CRF1) blockade by a CFR1 selective antagonist NBI on the stress-enhanced motivation for food reward were also assessed. Methods Male Sprague-Dawley rats with chow available ad libitum in their home cages were trained to press a lever under a progressive-ratio schedule for deliveries of either standard or high-fat food pellets. For testing yohimbine stress effects, rats received an intraperitoneal administration of yohimbine 10 min before start of the test sessions. For testing effects of CRF1 receptor blockade on stress responses, NBI was administered 20 min prior to yohimbine challenge. Results The rats emitted higher levels of lever responses to procure the high-fat food pellets compared with their counterparts on standard food pellets. Yohimbine challenge facilitated lever responses for the reward in all of the rats, whereas the effect was more robust in the rats on high-fat food pellets compared with their counterparts on standard food pellets. An inhibitory effect of pretreatment with NBI was observed on the enhancing effect of yohimbine challenge but not on the responses under baseline condition without yohimbine administration. Conclusions Stress challenge significantly enhanced the motivation of satiated rats to procure extra food reward, especially the high-fat food pellets. Activation of CRF1 receptors is required for the stress-enhanced motivation for food reward. These results may have implications for our better understanding of the biobehavioral mechanisms of overeating and obesity. PMID:25510859

Enhanced motivation for food reward induced by stress and attenuation by corticotrophin-releasing factor receptor antagonism in rats: implications for overeating and obesity.

PubMed

Liu, Xiu

2015-06-01

Overeating beyond individuals' homeostatic needs critically contributes to obesity. The neurobehavioral mechanisms underlying the motivation to consume excessive foods with high calories are not fully understood. The present study examined whether a pharmacological stressor, yohimbine, enhances the motivation to procure food reward with an emphasis on comparisons between standard lab chow and high-fat foods. The effects of corticotropin-releasing factor (CRF) receptor blockade by a CRF1-selective antagonist NBI on the stress-enhanced motivation for food reward were also assessed. Male Sprague-Dawley rats with chow available ad libitum in their home cages were trained to press a lever under a progressive ratio schedule for deliveries of either standard or high-fat food pellets. For testing yohimbine stress effects, rats received an intraperitoneal administration of yohimbine 10 min before start of the test sessions. For testing effects of CRF1 receptor blockade on stress responses, NBI was administered 20 min prior to yohimbine challenge. The rats emitted higher levels of lever responses to procure the high-fat food pellets compared with their counterparts on standard food pellets. Yohimbine challenge facilitated lever responses for the reward in all of the rats, whereas the effect was more robust in the rats on high-fat food pellets compared with their counterparts on standard food pellets. An inhibitory effect of pretreatment with NBI was observed on the enhancing effect of yohimbine challenge but not on the responses under baseline condition without yohimbine administration. Stress challenge significantly enhanced the motivation of satiated rats to procure extra food reward, especially the high-fat food pellets. Activation of CRF1 receptors is required for the stress-enhanced motivation for food reward. These results may have implications for our better understanding of the biobehavioral mechanisms of overeating and obesity.

Impact of body image on patients' attitude towards conventional, minimal invasive, and natural orifice surgery.

PubMed

Lamadé, Wolfram; Friedrich, Colin; Ulmer, Christoph; Basar, Tarkan; Weiss, Heinz; Thon, Klaus-Peter

2011-03-01

A series of investigations proposed that patients' preference on minimal invasive and scarless surgery may be influenced by age, sex, and surgical as well as endoscopic history of the individual patient. However, it is unknown which psychological criteria lead to the acceptance of increased personal surgical risk or increased personal expenses in patients demanding scarless operations. We investigated whether individual body image contributes to the patient's readiness to assume higher risk in favor of potentially increased cosmesis. We conducted a nonrandomized survey among 63 consecutive surgical patients after receiving surgery. Individual body image perception was assessed postoperatively applying the FKB-20 questionnaire extended by four additional items. The FKB-20 questionnaire is a validated tool for measuring body image disturbances resulting in a two-dimensional score with negative body image (NBI) and vital body dynamics (VBD) being the two resulting scores. A subgroup analysis was performed according to the conducted operations: conventional open surgery = group 1, traditional laparoscopic surgery = group 2, and no scar surgery = group 3. There was a significant correlation between a negative body image and the preference for scar sparing and scarless surgery indicated by a significantly increased acceptance of surgical risks and the willingness to spend additional money for receiving scarless surgery (r = 0.333; p = 0.0227). Allocated to operation subgroups, 17 of 63 patients belonged to group 1 (OS), 29 to group 2 (minimally invasive surgery), and 17 patients to group 3 (no scar). Although age and sex were unequally distributed, the groups were homogenous regarding body mass index and body image (NBI). Subgroup analysis revealed that postoperative desire for scar sparing approaches was most frequently expressed by patients who received no scar operations. Patients with an NBI tend towards scarless surgery and are willing to accept increased operative risk and to spend additional money for improved postoperative cosmesis.

Polyp detection rates using magnification with narrow band imaging and white light.

PubMed

Gilani, Nooman; Stipho, Sally; Panetta, James D; Petre, Sorin; Young, Michele A; Ramirez, Francisco C

2015-05-16

To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other's findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ(2) test and means were compared using the Student's t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light (WL) → narrow band imaging (NBI)]; narrow band imaging followed by white light (Group B: NBI → WL) and, white light followed by white light (Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. Three hundred patients were studied (100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups (23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C (P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A (6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B (18.9 ± 0.7 min and 17.6 ± 0.6 min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively (P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look (WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first (29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia (defined by size only) missed during the first look. Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps' and adenomas.

Polyp detection rates using magnification with narrow band imaging and white light

PubMed Central

Gilani, Nooman; Stipho, Sally; Panetta, James D; Petre, Sorin; Young, Michele A; Ramirez, Francisco C

2015-01-01

AIM: To compare the yield of adenomas between narrow band imaging and white light when using high definition/magnification. METHODS: This prospective, non-randomized comparative study was performed at the endoscopy unit of veteran affairs medical center in Phoenix, Arizona. Consecutive patients undergoing first average risk colorectal cancer screening colonoscopy were selected. Two experienced gastroenterologists performed all the procedures that were blinded to each other’s findings. Demographic details were recorded. Data are presented as mean ± SEM. Proportional data were compared using the χ2 test and means were compared using the Student’s t test. Tandem colonoscopy was performed in a sequential and segmental fashion using one of 3 strategies: white light followed by narrow band imaging [Group A: white light (WL) → narrow band imaging (NBI)]; narrow band imaging followed by white light (Group B: NBI → WL) and, white light followed by white light (Group C: WL → WL). Detection rate of missed polyps and adenomas were evaluated in all three groups. RESULTS: Three hundred patients were studied (100 in each Group). Although the total time for the colonoscopy was similar in the 3 groups (23.8 ± 0.7, 22.2 ± 0.5 and 24.1 ± 0.7 min for Groups A, B and C, respectively), it reached statistical significance between Groups B and C (P < 0.05). The cecal intubation time in Groups B and C was longer than for Group A (6.5 ± 0.4 min and 6.5 ± 0.4 min vs 4.9 ± 0.3 min; P < 0.05). The withdrawal time for Groups A and C was longer than Group B (18.9 ± 0.7 min and 17.6 ± 0.6 min vs 15.7 ± 0.4 min; P < 0.05). Overall miss rate for polyps and adenomas detected in three groups during the second look was 18% and 17%, respectively (P = NS). Detection rate for polyps and adenomas after first look with white light was similar irrespective of the light used during the second look (WL → WL: 13.7% for polyps, 12.6% for adenomas; WL → NBI: 14.2% for polyps, 11.3% for adenomas). Miss rate of polyps and adenomas however was significantly higher when NBI was used first (29.3% and 30.3%, respectively; P < 0.05). Most missed adenomas were ≤ 5 mm in size. There was only one advanced neoplasia (defined by size only) missed during the first look. CONCLUSION: Our data suggest that the tandem nature of the procedure rather than the optical techniques was associated with the detection of additional polyps’ and adenomas. PMID:25992195

The Ways of White Folks: A Love Letter to the National Education Association

ERIC Educational Resources Information Center

Lyne, Bill

2017-01-01

In July 2015, on the recommendation of the NEA Executive Committee and the NEA Board of Directors, the NEA Representative Assembly unanimously passed New Business Item B (NBI B), in which NEA declared itself ready to combat "institutional racism." The organization declared the existence of institutional racism and committed to spend more…

Divertor Heat Flux Reduction and Detachment in the National Spherical Torus eXperiment.

NASA Astrophysics Data System (ADS)

Soukhanovskii, Vsevolod

2007-11-01

Steady-state handling of the heat flux is a critical divertor issue for both the International Thermonuclear Experimental Reactor and spherical torus (ST) devices. Because of an inherently compact divertor, it was thought that ST-based devices might not be able to fully utilize radiative and dissipative divertor techniques based on induced power and momentum loss. However, initial experiments conducted in the National Spherical Torus Experiment in an open geometry horizontal carbon plate divertor using 0.8 MA 2-6 MW NBI-heated lower single null H-mode plasmas at the lower end of elongations κ=1.8-2.4 and triangularities δ=0.45-0.75 demonstrated that high divertor peak heat fluxes, up to 6-10 MW/ m^2, could be reduced by 50-75% using a high-recycling radiative divertor regime with D2 injection. Furthermore, similar reduction was obtained with a partially detached divertor (PDD) at high D2 injection rates, however, it was accompanied by an X-point MARFE that quickly led to confinement degradation. Another approach takes advantage of the ST relation between strong shaping and high performance, and utilizes the poloidal magnetic flux expansion in the divertor region. Up to 60 % reduction in divertor peak heat flux was achieved at similar levels of scrape-off layer power by varying plasma shaping and thereby increasing the outer strike point (OSP) poloidal flux expansion from 4-6 to 18-22. In recent experiments conducted in highly-shaped 1.0-1.2 MA 6 MW NBI heated H-mode plasmas with divertor D2 injection at rates up to 10^22 s-1, a PDD regime with OSP peak heat flux 0.5-1.5 MW/m^2 was obtained without noticeable confinement degradation. Calculations based on a two point scrape-off layer model with parameterized power and momentum losses show that the short parallel connection length at the OSP sets the upper limit on the radiative exhaust channel, and both the impurity radiation and large momentum sink achievable only at high divertor neutral pressures are required for detachment.

Library/Media Centers in U.S. Public Schools: Growth, Staffing, and Resources. Full Report

ERIC Educational Resources Information Center

Tuck, Kathy D.; Holmes, Dwight R.

2016-01-01

At the request of New Business Item: 89 (NBI: 89) adopted at the 2015 NEA Representative Assembly, this study examines the extent to which students have access to public school library/media centers with qualified staff and up-to-date resources. The study explores trends in library/media center openings and closings as well as staffing patterns…

Extension of the operational regime of the LHD towards a deuterium experiment

NASA Astrophysics Data System (ADS)

Takeiri, Y.; Morisaki, T.; Osakabe, M.; Yokoyama, M.; Sakakibara, S.; Takahashi, H.; Nakamura, Y.; Oishi, T.; Motojima, G.; Murakami, S.; Ito, K.; Ejiri, A.; Imagawa, S.; Inagaki, S.; Isobe, M.; Kubo, S.; Masamune, S.; Mito, T.; Murakami, I.; Nagaoka, K.; Nagasaki, K.; Nishimura, K.; Sakamoto, M.; Sakamoto, R.; Shimozuma, T.; Shinohara, K.; Sugama, H.; Watanabe, K. Y.; Ahn, J. W.; Akata, N.; Akiyama, T.; Ashikawa, N.; Baldzuhn, J.; Bando, T.; Bernard, E.; Castejón, F.; Chikaraishi, H.; Emoto, M.; Evans, T.; Ezumi, N.; Fujii, K.; Funaba, H.; Goto, M.; Goto, T.; Gradic, D.; Gunsu, Y.; Hamaguchi, S.; Hasegawa, H.; Hayashi, Y.; Hidalgo, C.; Higashiguchi, T.; Hirooka, Y.; Hishinuma, Y.; Horiuchi, R.; Ichiguchi, K.; Ida, K.; Ido, T.; Igami, H.; Ikeda, K.; Ishiguro, S.; Ishizaki, R.; Ishizawa, A.; Ito, A.; Ito, Y.; Iwamoto, A.; Kamio, S.; Kamiya, K.; Kaneko, O.; Kanno, R.; Kasahara, H.; Kato, D.; Kato, T.; Kawahata, K.; Kawamura, G.; Kisaki, M.; Kitajima, S.; Ko, W. H.; Kobayashi, M.; Kobayashi, S.; Kobayashi, T.; Koga, K.; Kohyama, A.; Kumazawa, R.; Lee, J. H.; López-Bruna, D.; Makino, R.; Masuzaki, S.; Matsumoto, Y.; Matsuura, H.; Mitarai, O.; Miura, H.; Miyazawa, J.; Mizuguchi, N.; Moon, C.; Morita, S.; Moritaka, T.; Mukai, K.; Muroga, T.; Muto, S.; Mutoh, T.; Nagasaka, T.; Nagayama, Y.; Nakajima, N.; Nakamura, Y.; Nakanishi, H.; Nakano, H.; Nakata, M.; Narushima, Y.; Nishijima, D.; Nishimura, A.; Nishimura, S.; Nishitani, T.; Nishiura, M.; Nobuta, Y.; Noto, H.; Nunami, M.; Obana, T.; Ogawa, K.; Ohdachi, S.; Ohno, M.; Ohno, N.; Ohtani, H.; Okamoto, M.; Oya, Y.; Ozaki, T.; Peterson, B. J.; Preynas, M.; Sagara, S.; Saito, K.; Sakaue, H.; Sanpei, A.; Satake, S.; Sato, M.; Saze, T.; Schmitz, O.; Seki, R.; Seki, T.; Sharov, I.; Shimizu, A.; Shiratani, M.; Shoji, M.; Skinner, C.; Soga, R.; Stange, T.; Suzuki, C.; Suzuki, Y.; Takada, S.; Takahata, K.; Takayama, A.; Takayama, S.; Takemura, Y.; Takeuchi, Y.; Tamura, H.; Tamura, N.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Tanaka, T.; Tanaka, Y.; Toda, S.; Todo, Y.; Toi, K.; Toida, M.; Tokitani, M.; Tokuzawa, T.; Tsuchiya, H.; Tsujimura, T.; Tsumori, K.; Usami, S.; Velasco, J. L.; Wang, H.; Watanabe, T.-H.; Watanabe, T.; Yagi, J.; Yajima, M.; Yamada, H.; Yamada, I.; Yamagishi, O.; Yamaguchi, N.; Yamamoto, Y.; Yanagi, N.; Yasuhara, R.; Yatsuka, E.; Yoshida, N.; Yoshinuma, M.; Yoshimura, S.; Yoshimura, Y.

2017-10-01

As the finalization of a hydrogen experiment towards the deuterium phase, the exploration of the best performance of hydrogen plasma was intensively performed in the large helical device. High ion and electron temperatures, T i and T e, of more than 6 keV were simultaneously achieved by superimposing high-power electron cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value ≤ft< β \\right> . The high ≤ft< β \\right> regime around 4% was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with a wide range of edge plasma parameters. The existence of a no impurity accumulation regime, where the high performance plasma is maintained with high power heating  >10 MW, was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region.

Damping Rates of Energetic Particle Modes and Stability With Changing Equilibrium Conditions in the MST Reversed-Field Pinch

NASA Astrophysics Data System (ADS)

Sears, S. H.; Almagri, A. F.; Anderson, J. K.; Bonofiglo, P. J.; Capecchi, W.; Kim, J.

2016-10-01

The damping of Alfvenic waves is an important process, with implications varying from anomalous ion heating in laboratory and astrophysical plasmas to the stability of fusion alpha-driven modes in a burning plasma. With a 1 MW NBI on the MST, a controllable set of energetic particle modes (EPMs) and Alfvenic eigenmodes can be excited. We investigate the damping of these modes as a function of both magnetic and flow shear. Typical EPM damping rates are -104 s-1 in standard RFP discharges. Magnetic shear in the region of large energetic ion density is -2 cm-1 and can be increased up to -2.5 cm-1 by varying the boundary field. Continuum mode damping rates can be reduced up to 50%. New experiments use a bias probe to control the rotation profile. Accelerating the edge plasma relative to the rapidly rotating NBI-driven core decreases the flow shear, while decelerating the edge plasma increases the flow shear in the region of strong energetic ion population. Mode damping rates measured as a function of the local flow shear are compared to ideal MHD predictions. Work supported by US DOE.

Central Safety Factor and Normalized Beta Control Under Near-Zero Input Torque Constraints in DIII-D

NASA Astrophysics Data System (ADS)

Pajares, Andres; Wehner, William; Schuster, Eugenio; Burrell, Keith; Ferron, John; Walker, Michael; Humphreys, David; Lehigh University Team; Atomics Team, General

2017-10-01

DIII-D experiments have assessed the capability of combined central safety factor (q0) and normalized beta (βN) control under near-zero net torque to facilitate access to QH-mode with reverse Ip and normal Bt. Regulation of q0 and βN can prevent magneto-hydrodynamic instabilities that deteriorate plasma performance in discharges with a monotonically increasing safety-factor profile. Zero-input-torque scenarios are of special interest because future burning plasma tokamaks such as ITER will most likely operate with very low input torque, which makes these scenarios more susceptible to locked modes. To support studies of such scenarios, a controller for simultaneous regulation of q0 and βN has been developed using near-zero net input torque actuators including balanced neutral beam injection (NBI) and electron-cyclotron heating & current drive (ECH/ECCD). Experimental results show that in spite of the presence of locked modes the use of feedback control resulted in good tracking of the commanded q0 and βN when both ECCD/ECH and NBI were available. Supported by the US DOE under DE-SC0010661 and DE-FC02-04ER54698.

Investigation of the long-lived saturated internal mode and its control on the HL-2A tokamak

NASA Astrophysics Data System (ADS)

Wei, Deng; Yi, Liu; Xian-Qu, Wang; Wei, Chen; Yun-Bo, Dong; Ohdachi, S.; Xiao-Quan, Ji; Yong, Shen; Jian-Yong, Cao; Jun, Zhou; Bei-Bing, Feng; Yong-Gao, Li; Xian-Li, Huang; Jin-Ming, Gao; Xiao-Yu, Han; Mei, Huang; Xiao-Gang, Wang

2014-01-01

HL-2A plasmas heated by neutral beam injection (NBI) regularly exhibit n = 1 long-lived saturated magnetohydrodynamic instabilities. A reduction in the electron density and plasma stored energy and an increase in fast ion losses are usually observed in the presence of such perturbations. The observed long-lived saturated internal mode (LLM) occurs when the safety factor profile has a weak shear in a broad range of the plasma centre with qmin around unity. It is found that the ideal interchange mode can become marginally stable due to the weak magnetic shear reaching a critical value. The LLM, due to its pressure-driven feature, is destabilized by the strong interaction with fast ions in the low-shear region during the NBI. Furthermore, for the first time it is clearly observed that the LLMs can be suppressed by electron cyclotron resonant heating (ECRH), or by supersonic molecular beam injection in HL-2A plasmas. Low-n sidebands observed during the LLM are also suppressed by increasing the ECRH power. The control of LLMs is due to the change in the magnetic shear or in the pressure profile induced by the local heating or fuelling.

Thermoelectric properties of the electron-doped perovskites Sr1-xCaxTi1-yNbyO3

NASA Astrophysics Data System (ADS)

Fukuyado, J.; Narikiyo, K.; Akaki, M.; Kuwahara, H.; Okuda, T.

2012-02-01

We have investigated thermoelectric (TE) properties for single crystals of perovskites Sr1-xCaxTi1-yNbyO3 for 0 ⩽ x ⩽ 0.4 and 0 ⩽ y ⩽ 0.03 below room temperature (RT). We found that SrTi0.99Nb0.01O3 shows a large power factor at low temperature (PF=50 μW/K2 cm at 100 K ˜ 90 μW/K2 cm at 50 K) and the largest dimensionless TE figure-of-merit below 40 K (ZT ˜ 0.07) among the ever-reported materials. Such a large low-temperature TE response around a carrier concentration of 1020 cm-3 is due to a distinct electron-phonon interaction, which could relate to the superconducting state. We also found that the Ca2+ substitution for Sr2+ increases ZT at 300 K for Sr1-xCaxTi0.97Nb0.03O3 from 0.08 to 0.105. The enhancement of ZT around RT originates both in a large reduction of a thermal conductivity due to an introduced randomness into the crystal structure and in an unexpected enhancement of a Seebeck coefficient.

Current–voltage characteristics of manganite–titanite perovskite junctions

PubMed Central

Ifland, Benedikt; Peretzki, Patrick; Kressdorf, Birte; Saring, Philipp; Kelling, Andreas; Seibt, Michael

2015-01-01

Summary After a general introduction into the Shockley theory of current voltage (J–V) characteristics of inorganic and organic semiconductor junctions of different bandwidth, we apply the Shockley theory-based, one diode model to a new type of perovskite junctions with polaronic charge carriers. In particular, we studied manganite–titanate p–n heterojunctions made of n-doped SrTi1− yNbyO3, y = 0.002 and p-doped Pr1− xCaxMnO3, x = 0.34 having a strongly correlated electron system. The diffusion length of the polaron carriers was analyzed by electron beam-induced current (EBIC) in a thin cross plane lamella of the junction. In the J–V characteristics, the polaronic nature of the charge carriers is exhibited mainly by the temperature dependence of the microscopic parameters, such as the hopping mobility of the series resistance and a colossal electro-resistance (CER) effect in the parallel resistance. We conclude that a modification of the Shockley equation incorporating voltage-dependent microscopic polaron parameters is required. Specifically, the voltage dependence of the reverse saturation current density is analyzed and interpreted as a voltage-dependent electron–polaron hole–polaron pair generation and separation at the interface. PMID:26199851

U.S. Army Deployment Injury Surveillance Summary Calendar Year 2008. 1 January 2008 - 31 December 2008

DTIC Science & Technology

2009-09-15

region affected. In 2008, 831 NBI-related musculoskeletal conditions required medical air evacuation. Inflammation and Pain (Overuse) Joint...evacuation were inflammation and pain (overuse) (56 percent), joint derangement (16 percent), and strains/sprains/rupture (13 percent). The spine/back...extremities (14 percent). The leading specific injury-related musculoskeletal conditions were inflammation and pain (overuse) involving the lumbar

Progress Toward Steady State Tokamak Operation Exploiting the high bootstrap current fraction regime

NASA Astrophysics Data System (ADS)

Ren, Q.

2015-11-01

Recent DIII-D experiments have advanced the normalized fusion performance of the high bootstrap current fraction tokamak regime toward reactor-relevant steady state operation. The experiments, conducted by a joint team of researchers from the DIII-D and EAST tokamaks, developed a fully noninductive scenario that could be extended on EAST to a demonstration of long pulse steady-state tokamak operation. Fully noninductive plasmas with extremely high values of the poloidal beta, βp >= 4 , have been sustained at βT >= 2 % for long durations with excellent energy confinement quality (H98y,2 >= 1 . 5) and internal transport barriers (ITBs) generated at large minor radius (>= 0 . 6) in all channels (Te, Ti, ne, VTf). Large bootstrap fraction (fBS ~ 80 %) has been obtained with high βp. ITBs have been shown to be compatible with steady state operation. Because of the unusually large ITB radius, normalized pressure is not limited to low βN values by internal ITB-driven modes. βN up to ~4.3 has been obtained by optimizing the plasma-wall distance. The scenario is robust against several variations, including replacing some on-axis with off-axis neutral beam injection (NBI), adding electron cyclotron (EC) heating, and reducing the NBI torque by a factor of 2. This latter observation is particularly promising for extension of the scenario to EAST, where maximum power is obtained with balanced NBI injection, and to a reactor, expected to have low rotation. However, modeling of this regime has provided new challenges to state-of-the-art modeling capabilities: quasilinear models can dramatically underpredict the electron transport, and the Sauter bootstrap current can be insufficient. The analysis shows first-principle NEO is in good agreement with experiments for the bootstrap current calculation and ETG modes with a larger saturated amplitude or EM modes may provide the missing electron transport. Work supported in part by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-AC02-09CH11466, and the NMCFP of China under 2015GB110000 and 2015GB102000.

Can optical diagnosis of small colon polyps be accurate? Comparing standard scope without narrow banding to high definition scope with narrow banding.

PubMed

Ashktorab, Hassan; Etaati, Firoozeh; Rezaeean, Farahnaz; Nouraie, Mehdi; Paydar, Mansour; Namin, Hassan Hassanzadeh; Sanderson, Andrew; Begum, Rehana; Alkhalloufi, Kawtar; Brim, Hassan; Laiyemo, Adeyinka O

2016-07-28

To study the accuracy of using high definition (HD) scope with narrow band imaging (NBI) vs standard white light colonoscope without NBI (ST), to predict the histology of the colon polyps, particularly those < 1 cm. A total of 147 African Americans patients who were referred to Howard University Hospital for screening or, diagnostic or follow up colonoscopy, during a 12-mo period in 2012 were prospectively recruited. Some patients had multiple polyps and total number of polyps was 179. Their colonoscopies were performed by 3 experienced endoscopists who determined the size and stated whether the polyps being removed were hyperplastic or adenomatous polyps using standard colonoscopes or high definition colonoscopes with NBI. The histopathologic diagnosis was reported by pathologists as part of routine care. Of participants in the study, 55 (37%) were male and median (interquartile range) of age was 56 (19-80). Demographic, clinical characteristics, past medical history of patients, and the data obtained by two instruments were not significantly different and two methods detected similar number of polyps. In ST scope 89% of polyps were < 1 cm vs 87% in HD scope (P = 0.7). The ST scope had a positive predictive value (PPV) and positive likelihood ratio (PLR) of 86% and 4.0 for adenoma compared to 74% and 2.6 for HD scope. There was a trend of higher sensitivity for HD scope (68%) compare to ST scope (53%) with almost the same specificity. The ST scope had a PPV and PLR of 38% and 1.8 for hyperplastic polyp (HPP) compared to 42% and 2.2 for HD scope. The sensitivity and specificity of two instruments for HPP diagnosis were similar. Our results indicated that HD scope was more sensitive in diagnosis of adenoma than ST scope. Clinical diagnosis of HPP with either scope is less accurate compared to adenoma. Colonoscopy diagnosis is not yet fully matched with pathologic diagnosis of colon polyp. However with the advancement of both imaging and training, it may be possible to increase the sensitivity and specificity of the scopes and hence save money for eliminating time and the cost of Immunohistochemistry/pathology.

Recent progress of the JT-60SA project

NASA Astrophysics Data System (ADS)

Shirai, H.; Barabaschi, P.; Kamada, Y.; the JT-60SA Team

2017-10-01

The JT-60SA project has been implemented for the purpose of an early realization of fusion energy. With a powerful and versatile NBI and ECRF system, a flexible plasma-shaping capability, and various kinds of in-vessel coils to suppress MHD instabilities, JT-60SA plays an essential role in addressing the key physics and engineering issues of ITER and DEMO. It aims to achieve the long sustainment of high integrated performance plasmas under the high β N condition required in DEMO. The fabrication and installation of components and systems of JT-60SA procured by the EU and Japan are steadily progressing. The installation of toroidal field (TF) coils around the vacuum vessel started in December 2016. The commissioning of the cryogenic system and power supply system has been implemented in the Naka site, and JT-60SA will start operation in 2019. The JT-60SA research plan covers a wide area of issues in ITER and DEMO relevant operation regimes, and has been regularly updated on the basis of intensive discussion among European and Japanese researchers.

Advanced endoscopic imaging: European Society of Gastrointestinal Endoscopy (ESGE) Technology Review.

PubMed

East, James E; Vleugels, Jasper L; Roelandt, Philip; Bhandari, Pradeep; Bisschops, Raf; Dekker, Evelien; Hassan, Cesare; Horgan, Gareth; Kiesslich, Ralf; Longcroft-Wheaton, Gaius; Wilson, Ana; Dumonceau, Jean-Marc

2016-11-01

Background and aim: This technical review is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the utilization of advanced endoscopic imaging in gastrointestinal (GI) endoscopy. Methods: This technical review is based on a systematic literature search to evaluate the evidence supporting the use of advanced endoscopic imaging throughout the GI tract. Technologies considered include narrowed-spectrum endoscopy (narrow band imaging [NBI]; flexible spectral imaging color enhancement [FICE]; i-Scan digital contrast [I-SCAN]), autofluorescence imaging (AFI), and confocal laser endomicroscopy (CLE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendation and the quality of evidence. Main recommendations: 1. We suggest advanced endoscopic imaging technologies improve mucosal visualization and enhance fine structural and microvascular detail. Expert endoscopic diagnosis may be improved by advanced imaging, but as yet in community-based practice no technology has been shown consistently to be diagnostically superior to current practice with high definition white light. (Low quality evidence.) 2. We recommend the use of validated classification systems to support the use of optical diagnosis with advanced endoscopic imaging in the upper and lower GI tracts (strong recommendation, moderate quality evidence). 3. We suggest that training improves performance in the use of advanced endoscopic imaging techniques and that it is a prerequisite for use in clinical practice. A learning curve exists and training alone does not guarantee sustained high performances in clinical practice. (Weak recommendation, low quality evidence.) Conclusion: Advanced endoscopic imaging can improve mucosal visualization and endoscopic diagnosis; however it requires training and the use of validated classification systems. © Georg Thieme Verlag KG Stuttgart · New York.

Control system for 5 MW neutral beam ion source for SST1

NASA Astrophysics Data System (ADS)

Patel, G. B.; Onali, Raja; Sharma, Vivek; Suresh, S.; Tripathi, V.; Bandyopadhyay, M.; Singh, N. P.; Thakkar, Dipal; Gupta, L. N.; Singh, M. J.; Patel, P. J.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.

2006-01-01

This article describes the control system for a 5MW ion source of the NBI (neutral beam injector) for steady-state superconducting tokamak-1 (SST-1). The system uses both hardware and software solutions. It comprises a DAS (data acquisition system) and a control system. The DAS is used to read the voltage and current signals from eight filament heater power supplies and 24 discharge power supplies. The control system is used to adjust the filament heater current in order to achieve an effective control on the discharge current in the plasma box. The system consists of a VME (Verse Module Eurocard) system and C application program running on a VxWorks™ real-time operating system. A PID (proportional, integral, and differential) algorithm is used to control the filament heater current. Experiments using this system have shown that the discharge current can be controlled within 1% accuracy for a PID loop time of 20ms. Response of the control system to the pressure variation of the gas in the chamber has also been studied and compared with the results obtained from those of an uncontrolled system. The present approach increases the flexibility of the control system. It not only eases the control of the plasma but also allows an easy changeover to various operation scenarios.

Issues in Adaptive Planning

DTIC Science & Technology

1986-06-30

approach to the application of theorem proving to problem solving, Aritificial Intelligence 2 (1Q71), 18Q- 208. 4. Fikes, R., Hart, P. and Nilsson, N...by emphasizing the structure of knowledge. 1.2. Planning Literature The earliest work in planning in Artificial Intelligence grew out of the work on...References 1. Newell, A., Artificial Intelligence and the concept of mind, in Computer models of thought and language, Schank, R. and Colby, K. (editor

Non-inductive Hybrid Scenario-Transport and Turbulence at Reduced Plasma Torque

NASA Astrophysics Data System (ADS)

Thome, K. E.; Petty, C. C.; Pace, D. C.; Turco, F.; Rhodes, T. L.

2016-10-01

As the neutral beam injection (NBI) torque is lowered in steady-state hybrid plasmas via counter-beam injection, increased turbulence and thermal transport is observed, particularly in the ion channel. These discharges require Pco-NBI = 11 MW and PECH = 3 MW to achieve zero surface loop voltage. As the beam torque is reduced from 8.5 N-m to 4 N-m with βN 3 and q95 6 , the global confinement decreases from H 98 y , 2 of 1.5 to 1.2 . Local transport analysis using TRANSP shows that the lower torque discharges have increased ion thermal diffusivity across the whole profile and increased electron thermal diffusivity localized to the ρ = 0.7 region. Similarly, Doppler Backscattering shows increased density fluctuations at intermediate wavenumbers at the lower torque. However, fast-ion transport caused by off-axis fishbones favorably decreases from 0.7m2 /s to 0.1m2 /s as the torque is lowered, partially offsetting the thermal transport reduction. These measured changes in turbulence and transport are being compared to plasma simulations using TGLF/GYRO to better predict the confinement of future steady-state hybrids that will be primarily RF-heated. Work supported by the US DOE under DE-FC02-04ER54698.

Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments

DOE PAGES

Waltz, Ronald E.; Bass, Eric M.; Heidbrink, William W.; ...

2015-10-30

Recent experiments with the DIII-D tilted neutral beam injection (NBI) varying the beam energetic particle (EP) source profiles have provided strong evidence that unstable Alfven eigenmodes (AE) drive stiff EP transport at a critical EP density gradient. Here the critical gradient is identified by the local AE growth rate being equal to the local ITG/TEM growth rate at the same low toroidal mode number. The growth rates are taken from the gyrokinetic code GYRO. Simulation show that the slowing down beam-like EP distribution has a slightly lower critical gradient than the Maxwellian. The ALPHA EP density transport code, used tomore » validate the model, combines the low-n stiff EP critical density gradient AE mid-core transport with the energy independent high-n ITG/TEM density transport model controling the central core EP density profile. For the on-axis NBI heated DIII-D shot 146102, while the net loss to the edge is small, about half the birth fast ions are transported from the central core r/a < 0.5 and the central density is about half the slowing down density. Lastly, these results are in good agreement with experimental fast ion pressure profiles inferred from MSE constrained EFIT equilibria.« less

Acquisition and visualization techniques for narrow spectral color imaging.

PubMed

Neumann, László; García, Rafael; Basa, János; Hegedüs, Ramón

2013-06-01

This paper introduces a new approach in narrow-band imaging (NBI). Existing NBI techniques generate images by selecting discrete bands over the full visible spectrum or an even wider spectral range. In contrast, here we perform the sampling with filters covering a tight spectral window. This image acquisition method, named narrow spectral imaging, can be particularly useful when optical information is only available within a narrow spectral window, such as in the case of deep-water transmittance, which constitutes the principal motivation of this work. In this study we demonstrate the potential of the proposed photographic technique on nonunderwater scenes recorded under controlled conditions. To this end three multilayer narrow bandpass filters were employed, which transmit at 440, 456, and 470 nm bluish wavelengths, respectively. Since the differences among the images captured in such a narrow spectral window can be extremely small, both image acquisition and visualization require a novel approach. First, high-bit-depth images were acquired with multilayer narrow-band filters either placed in front of the illumination or mounted on the camera lens. Second, a color-mapping method is proposed, using which the input data can be transformed onto the entire display color gamut with a continuous and perceptually nearly uniform mapping, while ensuring optimally high information content for human perception.

The high-βN hybrid scenario for ITER and FNSF steady-state missions

DOE PAGES

Turco, Francesca; Petty, Clinton C.; Luce, Timothy C.; ...

2015-05-15

New experiments on DIII-D have demonstrated the steady-state potential of the hybrid scenario, with 1 MA of plasma current driven fully non-inductively and βN up to 3.7 sustained for ~3 s (~1.5 current diffusion time, τ R, in DIII-D), providing the basis for an attractive option for steady-state operation in ITER and FNSF. Excellent confinement is achieved (H 98y2~1.6) without performance limiting tearing modes. Furthermore, the hybrid regime overcomes the need for off-axis current drive efficiency, taking advantage of poloidal magnetic flux pumping that is believed to be the result of a saturated 3/2 tearing mode. This allows for efficientmore » current drive close to the axis, without deleterious sawtooth instabilities. In these experiments, the edge surface loop voltage is driven down to zero for >1 τ R when the poloidal β is increased above 1.9 at a plasma current of 1.0 MA and the ECH power is increased to 3.2 MW. Stationary operation of hybrid plasmas with all on-axis current drive is sustained at pressures slightly above the ideal no-wall limit, while the calculated ideal with-wall MHD limit is β N~4-4.5. Off-axis NBI power has been used to broaden the pressure and current profiles in this scenario, seeking to take advantage of higher predicted kink stability limits and lower values of the tearing stability index Δ', as calculated by the DCON and PEST3 codes. Our results are based on measured profiles that predict ideal limits at βN>4.5, 10% higher than the cases with on-axis NBI. A 0-D model, based on the present confinement, βN and shape values of the DIII-D hybrid scenario, shows that these plasmas are consistent with the ITER 9 MA, Q=5 mission and the FNSF 6.7 MA scenario with Q=3.5. With collisionality and edge safety factor values comparable to those envisioned for ITER and FNSF, the high-βN hybrid represents an attractive high performance option for the steady-state missions of these devices.« less

Investigation of plasma parameters at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

NASA Astrophysics Data System (ADS)

Wimmer, C.; Fantz, U.; Aza, E.; Jovović, J.; Kraus, W.; Mimo, A.; Schiesko, L.

2017-08-01

The Neutral Beam Injection (NBI) system for fusion devices like ITER and, beyond ITER, DEMO requires large scale sources for negative hydrogen ions. BATMAN (Bavarian Test Machine for Negative ions) is a test facility attached with the prototype source for the ITER NBI (1/8 source size of the ITER source), dedicated to physical investigations due to its flexible access for diagnostics and exchange of source components. The required amount of negative ions is produced by surface conversion of hydrogen atoms or ions on caesiated surfaces. Several diagnostic tools (Optical Emission Spectroscopy, Cavity Ring-Down Spectroscopy for H-, Langmuir probes, Tunable Diode Laser Absorption Spectroscopy for Cs) allow the determination of plasma parameters in the ion source. Plasma parameters for two modifications of the standard prototype source have been investigated: Firstly, a second Cs oven has been installed in the bottom part of the back plate in addition to the regularly used oven in the top part of the back plate. Evaporation from the top oven only can lead to a vertically asymmetric Cs distribution in front of the plasma grid. Using both ovens, a symmetric Cs distribution can be reached - however, in most cases no significant change of the extracted ion current has been determined for varying Cs symmetry if the source is well-conditioned. Secondly, BATMAN has been equipped with a much larger, racetrack-shaped RF driver (area of 32×58 cm2) instead of the cylindrical RF driver (diameter of 24.5 cm). The main idea is that one racetrack driver could substitute two cylindrical drivers in larger sources with increased reliability and power efficiency. For the same applied RF power, the electron density is lower in the racetrack driver due to its five times higher volume. The fraction of hydrogen atoms to molecules, however, is at a similar level or even slightly higher, which is a promising result for application in larger sources.

Analysis of Alfven eigenmode destabilization in DIII-D high poloidal β discharges using a Landau closure model

NASA Astrophysics Data System (ADS)

Varela, J.; Spong, D. A.; Garcia, L.; Huang, J.; Murakami, M.; Garofalo, A. M.; Qian, J. P.; Holcomb, C. T.; Hyatt, A. W.; Ferron, J. R.; Collins, C. S.; Ren, Q. L.; McClenaghan, J.; Guo, W.

2018-07-01

Alfvén eigenmodes are destabilized at the DIII-D pedestal during transient beta drops in high poloidal β discharges with internal transport barriers (ITBs), driven by n  =  1 external kink modes, leading to energetic particle losses. There are two different scenarios in the thermal β recovery phase: with bifurcation (two instability branches with different frequencies) or without bifurcation (single instability branch). We use the reduced MHD equations in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particles as well as the geodesic acoustic wave dynamics, to study the properties of the instabilities observed in the DIII-D high poloidal β discharges and identify the conditions to trigger the bifurcation. The simulations suggest that instabilities with lower frequency in the bifurcation case are ballooning modes driven at the plasma pedestal, while the instability branch with higher frequencies are low n (n  <  4) toroidal Alfvén eigenmodes nearby the pedestal. The reverse shear region between the middle and plasma periphery in the non-bifurcated case avoids the excitation of ballooning modes at the pedestal, although toroidal Alfvén eigenmodes and reverse shear Alfvén eigenmodes are unstable in the reverse shear region. The n  =  1 and n  =  2 Alfvén eigenmode activity can be suppressed or minimized if the neutral beam injector (NBI) intensity is lower than the experimental value (). In addition, if the beam energy or neutral beam injector voltage is lower than in the experiment (), the resonance between beam and thermal plasma is weaker. The and 6 AE activity can not be fully suppressed, although the growth rate and frequency is smaller for an optimized neutral beam injector operation regime. In conclusion, AE activity in high poloidal β discharges can be minimized for optimized NBI operation regimes.

Serrated polyps of the colon and rectum: Endoscopic features including image enhanced endoscopy

PubMed Central

Saito, Shoichi; Tajiri, Hisao; Ikegami, Masahiro

2015-01-01

In this review, I outline the characteristic endoscopic findings of serrated lesions of the colorectum based on image enhanced endoscopy (IEE). Histopathologically, lesions with serrated structures are typically classified into the following three types based: hyperplastic polyps (HPs), traditional serrated adenomas (TSAs), and sessile serrated adenoma/polyps (SSA/Ps). Both HP and SSA/P often present as dark-green colors on auto fluorescence imaging (AFI) colonoscopy that are similar to the normal surrounding mucosa. In contrast, TSAs often have elevated shapes and present as magenta colors that are similar to the tubular adenomas. The superficial type of TSA also includes many lesions that present as magenta colors. When SSA/Ps are associated with cytological dysplasia, many lesions present with magenta colors, whereas lesions that are not associated with cytological dysplasia present with dark-green colors. When observed via narrow band imaging (NBI), many SSA/P include lesions with strong mucous adhesions. Because these lesions are observed with reddish mucous adhesions, we refer to them as “red cap sign” and place such signs among the typical findings of SSA/P. Because the dilatation of the pit in SSA/P is observed as a round/oval black dot on magnified observations, we refer to this finding as II-dilatation pit (II-D pit) and also positioned it as a characteristic finding of SSA/P. In contrast, dilatations of the capillary vessels surrounding the glands, such as those that occur in tubular adenoma, are not considered to be useful for differentiating HPs from SSA/Ps. However, in cases in which SSA/P is associated with cytological dysplasia, the dilatation of capillary vessels is observed in the same area. When submucosal layer invasion occurs in the same area, the blood flow presents with irregularities that are similar to those of common colorectal cancer at an early stage and disappears as the invasion proceeds deeply. The surface pattern of invasive cancer that is observed at the tumor surface is also likely to disappear. Based on the above results, we considered that the differentiations between HP and TSA, between TSA and SSA/P, and between HP and SSA/P might become easier due to the concomitant use of white light observation and IEE. We also concluded that AFI and NBI can be useful modalities for SSA/P lesions associated with cytological dysplasia. PMID:26240687

Mapping vegetation cover and biomass on the Qinghai-Tibet-Plateau using hyperspectral measurements and multispectral satellite images

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Nauss, Thomas; Bendix, Jörg

2016-04-01

Pastoralism is the dominant land-use on the Qinghai-Tibet-Plateau (QTP) providing the major economic resource for the local population. However, the pastures are highly supposed to be affected by ongoing degradation whose extent is still disputed. This study uses hyperspectral in situ measurements and multispectral satellite images to assess vegetation cover and above ground biomass (AGB) as proxies of pasture degradation on a regional scale. Using Random Forests in conjunction with recursive feature selection as modeling tool, it is tested whether the full hyperspectral information is needed or if multispectral information is sufficient to accurately estimate vegetation cover and AGB. To regionalize pasture degradation proxies, the transferability of the locally derived models to high resolution multispectral satellite data is assessed. For this purpose, 1183 hyperspectral measurements and vegetation records were sampled at 18 locations on the QTP. AGB was determined on 25 0.5x0.5m plots. Proxies for pasture degradation were derived from the spectra by calculating narrow-band indices (NBI). Using the NBI as predictor variables vegetation cover and AGB were modeled. Models were calculated using the hyperspectral data as well as the same data resampled to WorldView-2, QuickBird and RapidEye channels. The hyperspectral results were compared to the multispectral results. Finally, the models were applied to satellite data to map vegetation cover and AGB on a regional scale. Vegetation cover was accurately predicted by Random Forest if hyperspectral measurements were used. In contrast, errors in AGB estimations were considerably higher. Only small differences in accuracy were observed between the models based on hyper- compared to multispectral data. The application of the models to satellite images generally resulted in an increase of the estimation error. Though this reflects the challenge of applying in situ measurements to satellite data, the results still show a high potential to map pasture degradation proxies on the QTP even for larger scales.

Endoscopists can sustain high performance for the optical diagnosis of colorectal polyps following standardized and continued training.

PubMed

McGill, Sarah K; Soetikno, Roy; Rastogi, Amit; Rouse, Robert V; Sato, Tohru; Bansal, Ajay; McQuaid, Kenneth; Kaltenbach, Tonya

2015-03-01

The learning curve for optical diagnosis of colorectal polyps with the narrow-band imaging (NBI) is unknown. To forego histological analysis of diminutive polyps diagnosed optically with high confidence, guidelines recommend ≥ 90 % negative predictive value (NPV) and concordance of ≥ 90 % for surveillance intervals predicted optically and histologically. We aimed to study the learning of optical diagnosis for colorectal polyps. We studied five endoscopists as part of a randomized multisite trial comparing near-focus and standard-focus views for optical diagnosis. They trained using a computer-based module, followed by 10 real-time colonoscopies with pathology correlation. Endoscopists then optically diagnosed and resected all the polyps found during 558 consecutive colonoscopies, and diagnoses were compared with pathology. Endoscopists repeated the training module at the study midpoint. NPV and concordance of surveillance intervals for diminutive polyps diagnosed optically with high confidence were measured over time. Endoscopists showed high diagnostic performance, with a nonsignificant trend toward higher NPV in the second half of the study. For the 445 polyps in the standard-view arm, the NPV was 88.0 % (95 %CI 75.7 % - 95.5 %) in the first half and 95.8 % (88.3 % - 99.1 %) in the second; P = 0.7. Three endoscopists in the first half and four in the second achieved > 90 % NPV. Concordance of surveillance intervals was identical in the first and second halves at 98.1 % (95 %CI 93.3 % - 99.8 %). High NPV for the prediction of non-neoplasms with NBI was achieved and maintained in this group of endoscopists who participated in standardized and continued training. Both NPV and surveillance interval agreement indicated high performance in the optical diagnosis of colorectal polyps and exceeded thresholds. © Georg Thieme Verlag KG Stuttgart · New York.

Physics-based investigation of negative ion behavior in a negative-ion-rich plasma using integrated diagnostics

NASA Astrophysics Data System (ADS)

Tsumori, K.; Takeiri, Y.; Ikeda, K.; Nakano, H.; Geng, S.; Kisaki, M.; Nagaoka, K.; Tokuzawa, T.; Wada, M.; Sasaki, K.; Nishiyama, S.; Goto, M.; Osakabe, M.

2017-08-01

Total power of 16 MW has been successfully delivered to the plasma confined in the Large Helical Device (LHD) from three Neutral Beam Injectors (NBIs) equipped with negative hydrogen (H-) ion sources. However, the detailed mechanisms from production through extraction of H- ions are still yet to be clarified and a similar size ion source on an independent acceleration test bench called Research and development Negative Ion Source (RNIS) serves as the facility to study physics related to H- production and transport for further improvement of NBI. The production of negative-ion-rich plasma and the H- ions behavior in the beam extraction region in RNIS is being investigated by employing an integrated diagnostic system. Flow patterns of electrons, positive ions and H- ions in the extraction region are described in a two-dimensional map. The measured flow patterns indicate the existence a stagnation region, where the H- flow changes the direction at a distance about 20 mm from the plasma grid. The pattern also suggested the H- flow originated from plasma grid (PG) surface that turned back toward extraction apertures. The turning region seems formed by a layer of combined magnetic field produced by the magnetic filter field and the Electron-Deflection Magnetic (EDM) field created by magnets installed in the extraction electrode.

Establishment of a low recycling state with full density control by active pumping of the closed helical divertor at LHD

NASA Astrophysics Data System (ADS)

Motojima, G.; Masuzaki, S.; Tanaka, H.; Morisaki, T.; Sakamoto, R.; Murase, T.; Tsuchibushi, Y.; Kobayashi, M.; Schmitz, O.; Shoji, M.; Tokitani, M.; Yamada, H.; Takeiri, Y.; The LHD Experiment Group

2018-01-01

Superior control of particle recycling and hence full governance of plasma density has been established in the Large Helical Device (LHD) using largely enhanced active pumping of the closed helical divertor (CHD). In-vessel cryo-sorption pumping systems inside the CHD in five out of ten inner toroidal divertor sections have been developed and installed step by step in the LHD. The total effective pumping speed obtained was 67  ±  5 m3 s-1 in hydrogen, which is approximately seven times larger than previously obtained. As a result, a low recycling state was observed with CHD pumping for the first time in LHD featuring excellent density control even under intense pellet fueling conditions. A global particle confinement time (τ p* ) is used for comparison of operation with and without the CHD pumping. The τ p* was evaluated from the density decay after the fueling of hydrogen pellet injection or gas puffing in NBI plasmas. A reliably low base density before the fueling and short τ p* after the fueling were obtained during the CHD pumping, demonstrating for the first time full control of the particle balance with active pumping in the CHD.

Optimization of DIII-D discharges to avoid AE destabilization

NASA Astrophysics Data System (ADS)

Varela, Jacobo; Spong, Donald; Garcia, Luis; Huang, Juan; Murakami, Masanori

2017-10-01

The aim of the study is to analyze the stability of Alfven Eigenmodes (AE) perturbed by energetic particles (EP) during DIII-D operation. We identify the optimal NBI operational regimes that avoid or minimize the negative effects of AE on the device performance. We use the reduced MHD equations to describe the linear evolution of the poloidal flux and the toroidal component of the vorticity in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particles, including the effect of the acoustic modes. We add the Landau damping and resonant destabilization effects using a closure relation. We perform parametric studies of the MHD and AE stability, taking into account the experimental profiles of the thermal plasma and EP, also using a range of values of the energetic particles β, density and velocity as well the effect of the toroidal couplings. We reproduce the AE activity observed in high poloidal β discharge at the pedestal and reverse shear discharges. This material based on work is supported both by the U.S. Department of Energy, Office of Science, under Contract DE-AC05-00OR22725 with UT-Battelle, LLC. Research sponsored in part by the Ministerio de Economia y Competitividad of Spain under the project.

BioInfra.Prot: A comprehensive proteomics workflow including data standardization, protein inference, expression analysis and data publication.

PubMed

Turewicz, Michael; Kohl, Michael; Ahrens, Maike; Mayer, Gerhard; Uszkoreit, Julian; Naboulsi, Wael; Bracht, Thilo; Megger, Dominik A; Sitek, Barbara; Marcus, Katrin; Eisenacher, Martin

2017-11-10

The analysis of high-throughput mass spectrometry-based proteomics data must address the specific challenges of this technology. To this end, the comprehensive proteomics workflow offered by the de.NBI service center BioInfra.Prot provides indispensable components for the computational and statistical analysis of this kind of data. These components include tools and methods for spectrum identification and protein inference, protein quantification, expression analysis as well as data standardization and data publication. All particular methods of the workflow which address these tasks are state-of-the-art or cutting edge. As has been shown in previous publications, each of these methods is adequate to solve its specific task and gives competitive results. However, the methods included in the workflow are continuously reviewed, updated and improved to adapt to new scientific developments. All of these particular components and methods are available as stand-alone BioInfra.Prot services or as a complete workflow. Since BioInfra.Prot provides manifold fast communication channels to get access to all components of the workflow (e.g., via the BioInfra.Prot ticket system: bioinfraprot@rub.de) users can easily benefit from this service and get support by experts. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Test of the Hill Stability Criterion against Chaos Indicators

NASA Astrophysics Data System (ADS)

Satyal, Suman; Quarles, Billy; Hinse, Tobias

2012-10-01

The efficacy of Hill Stability (HS) criterion is tested against other known chaos indicators such as Maximum Lyapunov Exponents (MLE) and Mean Exponential Growth of Nearby Orbits (MEGNO) maps. First, orbits of four observationally verified binary star systems: γ Cephei, Gliese-86, HD41004, and HD196885 are integrated using standard integration packages (MERCURY, SWIFTER, NBI, C/C++). The HS which measures orbital perturbation of a planet around the primary star due to the secondary star is calculated for each system. The LEs spectra are generated to measure the divergence/convergence rate of stable manifolds and the MEGNO maps are generated by using the variational equations of the system during the integration process. These maps allow to accurately differentiate between stable and unstable dynamical systems. Then the results obtained from the analysis of HS, MLE, and MEGNO maps are checked for their dynamical variations and resemblance. The HS of most of the planets seems to be stable, quasi-periodic for at least ten million years. The MLE and the MEGNO maps also indicate the local quasi-periodicity and global stability in relatively short integration period. The HS criterion is found to be a comparably efficient tool to measure the stability of planetary orbits.

Can optical diagnosis of small colon polyps be accurate? Comparing standard scope without narrow banding to high definition scope with narrow banding

PubMed Central

Ashktorab, Hassan; Etaati, Firoozeh; Rezaeean, Farahnaz; Nouraie, Mehdi; Paydar, Mansour; Namin, Hassan Hassanzadeh; Sanderson, Andrew; Begum, Rehana; Alkhalloufi, Kawtar; Brim, Hassan; Laiyemo, Adeyinka O

2016-01-01

AIM: To study the accuracy of using high definition (HD) scope with narrow band imaging (NBI) vs standard white light colonoscope without NBI (ST), to predict the histology of the colon polyps, particularly those < 1 cm. METHODS: A total of 147 African Americans patients who were referred to Howard University Hospital for screening or, diagnostic or follow up colonoscopy, during a 12-mo period in 2012 were prospectively recruited. Some patients had multiple polyps and total number of polyps was 179. Their colonoscopies were performed by 3 experienced endoscopists who determined the size and stated whether the polyps being removed were hyperplastic or adenomatous polyps using standard colonoscopes or high definition colonoscopes with NBI. The histopathologic diagnosis was reported by pathologists as part of routine care. RESULTS: Of participants in the study, 55 (37%) were male and median (interquartile range) of age was 56 (19-80). Demographic, clinical characteristics, past medical history of patients, and the data obtained by two instruments were not significantly different and two methods detected similar number of polyps. In ST scope 89% of polyps were < 1 cm vs 87% in HD scope (P = 0.7). The ST scope had a positive predictive value (PPV) and positive likelihood ratio (PLR) of 86% and 4.0 for adenoma compared to 74% and 2.6 for HD scope. There was a trend of higher sensitivity for HD scope (68%) compare to ST scope (53%) with almost the same specificity. The ST scope had a PPV and PLR of 38% and 1.8 for hyperplastic polyp (HPP) compared to 42% and 2.2 for HD scope. The sensitivity and specificity of two instruments for HPP diagnosis were similar. CONCLUSION: Our results indicated that HD scope was more sensitive in diagnosis of adenoma than ST scope. Clinical diagnosis of HPP with either scope is less accurate compared to adenoma. Colonoscopy diagnosis is not yet fully matched with pathologic diagnosis of colon polyp. However with the advancement of both imaging and training, it may be possible to increase the sensitivity and specificity of the scopes and hence save money for eliminating time and the cost of Immunohistochemistry/pathology. PMID:27605888

Progress of long pulse operation with high performance plasma in KSTAR

NASA Astrophysics Data System (ADS)

Bae, Young; Kstar Team

2015-11-01

Recent KSTAR experiments showed the sustained H-mode operation up to the pulse duration of 46 s at the plasma current of 600 kA. The long-pulse H-mode operation has been supported by long-pulse capable neutral beam injection (NBI) system with high NB current drive efficiency attributed by highly tangential injections of three beam sources. In next phase, aiming to demonstrate the long pulse stationary high performance plasma operation, we are attempting the long pulse inductive operation at the higher performance (MA plasma current, high normalized beta, and low q95) for the final goal of demonstration of ITER-like baseline scenario in KSTAR with progressive improvement of the plasma shape control and higher neutral beam injection power. This paper presents the progress of long pulse operation and the analysis of energy confinement time and non-inductive current drive in KSTAR.

Studies on Typhus and Spotted Fever.

DTIC Science & Technology

1980-02-01

prowazekii-infected human somatic (fibroblast, endothelia)), but not chick, mouse or monkey , cells in culture: (a) intracellular antirickettsial action...that of the controls. No such effect on growth was apparent in CE cells, Nu E % o0 M Ŕ ZOO - .0 E 00 (1 CI - 4D W = .) C ~ o r- -!NBI Go !N 21501,,o o...human origin transformed or malignant cells, monkey primary or diploid and primary mouse embryo fibroblasts will permit expression of these effects to

Analysis of resonant fast ion distributions during combined ICRF and NBI heating with transients using neutron emission spectroscopy

NASA Astrophysics Data System (ADS)

Hellesen, C.; Mantsinen, M.; Conroy, S.; Ericsson, G.; Eriksson, J.; Kiptily, V. G.; Nabais, F.; Contributors, JET

2018-05-01

ICRF heating at the fundamental cyclotron frequency of a hydrogen minority ion species also gives rise to a partial power absorption by deuterium ions at their second harmonic resonance. This paper studies the deuterium distributions resulting from such 2nd harmonic heating at JET using neutron emission spectroscopy data from the time of flight spectrometer TOFOR. The fast deuterium distributions are obtained over the energy range 100 keV to 2 MeV. Specifically, we study how the fast deuterium distributions vary as ICRF heating is used alone as well as in combination with NBI heating. When comparing the different heating scenarios, we observed both a difference in the shapes of the distributions as well as in their absolute level. The differences are most pronounced below 0.5 MeV. Comparisons are made with corresponding distributions calculated with the code PION. We find a good agreement between the measured distributions and those calculated with PION, both in terms of their shapes as well as their amplitudes. However, we also identified a period with signs of an inverted fast ion distribution, which showed large disagreements between the modeled and measured results. Resonant interactions with tornado modes, i.e. core localized toroidal alfven eigenmodes (TAEs), are put forward as a possible explanation for the inverted distribution.

Plasma rotation and transport in MAST spherical tokamak

NASA Astrophysics Data System (ADS)

Field, A. R.; Michael, C.; Akers, R. J.; Candy, J.; Colyer, G.; Guttenfelder, W.; Ghim, Y.-c.; Roach, C. M.; Saarelma, S.; MAST Team

2011-06-01

The formation of internal transport barriers (ITBs) is investigated in MAST spherical tokamak plasmas. The relative importance of equilibrium flow shear and magnetic shear in their formation and evolution is investigated using data from high-resolution kinetic- and q-profile diagnostics. In L-mode plasmas, with co-current directed NBI heating, ITBs in the momentum and ion thermal channels form in the negative shear region just inside qmin. In the ITB region the anomalous ion thermal transport is suppressed, with ion thermal transport close to the neo-classical level, although the electron transport remains anomalous. Linear stability analysis with the gyro-kinetic code GS2 shows that all electrostatic micro-instabilities are stable in the negative magnetic shear region in the core, both with and without flow shear. Outside the ITB, in the region of positive magnetic shear and relatively weak flow shear, electrostatic micro-instabilities become unstable over a wide range of wave numbers. Flow shear reduces the linear growth rates of low-k modes but suppression of ITG modes is incomplete, which is consistent with the observed anomalous ion transport in this region; however, flow shear has little impact on growth rates of high-k, electron-scale modes. With counter-NBI ITBs of greater radial extent form outside qmin due to the broader profile of E × B flow shear produced by the greater prompt fast-ion loss torque.

Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

NASA Astrophysics Data System (ADS)

Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

2012-10-01

A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

Overview of results from the MST reversed field pinch experiment

NASA Astrophysics Data System (ADS)

Sarff, J. S.; Almagri, A. F.; Anderson, J. K.; Borchardt, M.; Carmody, D.; Caspary, K.; Chapman, B. E.; Den Hartog, D. J.; Duff, J.; Eilerman, S.; Falkowski, A.; Forest, C. B.; Goetz, J. A.; Holly, D. J.; Kim, J.-H.; King, J.; Ko, J.; Koliner, J.; Kumar, S.; Lee, J. D.; Liu, D.; Magee, R.; McCollam, K. J.; McGarry, M.; Mirnov, V. V.; Nornberg, M. D.; Nonn, P. D.; Oliva, S. P.; Parke, E.; Reusch, J. A.; Sauppe, J. P.; Seltzman, A.; Sovinec, C. R.; Stephens, H.; Stone, D.; Theucks, D.; Thomas, M.; Triana, J.; Terry, P. W.; Waksman, J.; Bergerson, W. F.; Brower, D. L.; Ding, W. X.; Lin, L.; Demers, D. R.; Fimognari, P.; Titus, J.; Auriemma, F.; Cappello, S.; Franz, P.; Innocente, P.; Lorenzini, R.; Martines, E.; Momo, B.; Piovesan, P.; Puiatti, M.; Spolaore, M.; Terranova, D.; Zanca, P.; Belykh, V.; Davydenko, V. I.; Deichuli, P.; Ivanov, A. A.; Polosatkin, S.; Stupishin, N. V.; Spong, D.; Craig, D.; Harvey, R. W.; Cianciosa, M.; Hanson, J. D.

2013-10-01

An overview of recent results from the MST programme on physics important for the advancement of the reversed field pinch (RFP) as well as for improved understanding of toroidal magnetic confinement more generally is reported. Evidence for the classical confinement of ions in the RFP is provided by analysis of impurity ions and energetic ions created by 1 MW neutral beam injection (NBI). The first appearance of energetic-particle-driven modes by NBI in a RFP plasma is described. MST plasmas robustly access the quasi-single-helicity state that has commonalities to the stellarator and ‘snake’ formation in tokamaks. In MST the dominant mode grows to 8% of the axisymmetric field strength, while the remaining modes are reduced. Predictive capability for tearing mode behaviour has been improved through nonlinear, 3D, resistive magnetohydrodynamic computation using the measured resistivity profile and Lundquist number, which reproduces the sawtooth cycle dynamics. Experimental evidence and computational analysis indicates two-fluid effects, e.g., Hall physics and gyro-viscosity, are needed to understand the coupling of parallel momentum transport and current profile relaxation. Large Reynolds and Maxwell stresses, plus separately measured kinetic stress, indicate an intricate momentum balance and a possible origin for MST's intrinsic plasma rotation. Gyrokinetic analysis indicates that micro-tearing modes can be unstable at high beta, with a critical gradient for the electron temperature that is larger than for tokamak plasmas by roughly the aspect ratio.

A comparison of blood vessel features and local binary patterns for colorectal polyp classification

NASA Astrophysics Data System (ADS)

Gross, Sebastian; Stehle, Thomas; Behrens, Alexander; Auer, Roland; Aach, Til; Winograd, Ron; Trautwein, Christian; Tischendorf, Jens

2009-02-01

Colorectal cancer is the third leading cause of cancer deaths in the United States of America for both women and men. By means of early detection, the five year survival rate can be up to 90%. Polyps can to be grouped into three different classes: hyperplastic, adenomatous, and carcinomatous polyps. Hyperplastic polyps are benign and are not likely to develop into cancer. Adenomas, on the other hand, are known to grow into cancer (adenoma-carcinoma sequence). Carcinomas are fully developed cancers and can be easily distinguished from adenomas and hyperplastic polyps. A recent narrow band imaging (NBI) study by Tischendorf et al. has shown that hyperplastic polyps and adenomas can be discriminated by their blood vessel structure. We designed a computer-aided system for the differentiation between hyperplastic and adenomatous polyps. Our development aim is to provide the medical practitioner with an additional objective interpretation of the available image data as well as a confidence measure for the classification. We propose classification features calculated on the basis of the extracted blood vessel structure. We use the combined length of the detected blood vessels, the average perimeter of the vessels and their average gray level value. We achieve a successful classification rate of more than 90% on 102 polyps from our polyp data base. The classification results based on these features are compared to the results of Local Binary Patterns (LBP). The results indicate that the implemented features are superior to LBP.

New ion source for KSTAR neutral beam injection system.

PubMed

Kim, Tae-Seong; Jeong, Seung Ho; In, Sang-Ryul

2012-02-01

The neutral beam injection system (NBI-1) of the KSTAR tokamak can accommodate three ion sources; however, it is currently equipped with only one prototype ion source. In the 2010 and 2011 KSTAR campaigns, this ion source supplied deuterium neutral beam power of 0.7-1.6 MW to the KSTAR plasma with a beam energy of 70-100 keV. A new ion source will be prepared for the 2012 KSTAR campaign with a much advanced performance compared with the previous one. The newly designed ion source has a very large transparency (∼56%) without deteriorating the beam optics, which is designed to deliver a 2 MW injection power of deuterium beams at 100 keV. The plasma generator of the ion source is of a horizontally cusped bucket type, and the whole inner wall, except the cathode filaments and plasma grid side, functions as an anode. The accelerator assembly consists of four multi-circular aperture grids made of copper and four electrode flanges made of aluminum alloy. The electrodes are insulated using PEEK. The ion source will be completed and tested in 2011.

The high-β{sub N} hybrid scenario for ITER and FNSF steady-state missions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turco, F.; Petty, C. C.; Luce, T. C.

2015-05-15

New experiments on DIII-D have demonstrated the steady-state potential of the hybrid scenario, with 1 MA of plasma current driven fully non-inductively and β{sub N} up to 3.7 sustained for ∼3 s (∼1.5 current diffusion time, τ{sub R}, in DIII-D), providing the basis for an attractive option for steady-state operation in ITER and FNSF. Excellent confinement is achieved (H{sub 98y2} ∼ 1.6) without performance limiting tearing modes. The hybrid regime overcomes the need for off-axis current drive efficiency, taking advantage of poloidal magnetic flux pumping that is believed to be the result of a saturated 3/2 tearing mode. This allows for efficient currentmore » drive close to the axis, without deleterious sawtooth instabilities. In these experiments, the edge surface loop voltage is driven down to zero for >1 τ{sub R} when the poloidal β is increased above 1.9 at a plasma current of 1.0 MA and the ECH power is increased to 3.2 MW. Stationary operation of hybrid plasmas with all on-axis current drive is sustained at pressures slightly above the ideal no-wall limit, while the calculated ideal with-wall MHD limit is β{sub N} ∼ 4–4.5. Off-axis Neutral Beam Injection (NBI) power has been used to broaden the pressure and current profiles in this scenario, seeking to take advantage of higher predicted kink stability limits and lower values of the tearing stability index Δ′, as calculated by the DCON and PEST3 codes. Results based on measured profiles predict ideal limits at β{sub N} > 4.5, 10% higher than the cases with on-axis NBI. A 0-D model, based on the present confinement, β{sub N} and shape values of the DIII-D hybrid scenario, shows that these plasmas are consistent with the ITER 9 MA, Q = 5 mission and the FNSF 6.7 MA scenario with Q = 3.5. With collisionality and edge safety factor values comparable to those envisioned for ITER and FNSF, the high-β{sub N} hybrid represents an attractive high performance option for the steady-state missions of these devices.« less

Delta Niobium or Delta VICE?

NASA Astrophysics Data System (ADS)

Hofmann, A. W.

2006-12-01

Delta Niobium or Delta VICE? Niobium is one of a few chemical elements that can be used to discriminate between melts derived from upwelling mantle, represented by MORBs and OIBs, and those derived from subduction and continental crust environments. The Nb/U ratio was introduced because these two elements appear to partition nearly identically in upwelling environments, but very differently (from one another) in subduction and continental environments (Hofmann et al., 1986). Fitton et al. (1997, 2003) have taken a radically different approach, using log(Nb/Y)-log(Zr/Y) correlations that appear to discriminate between MORB and OIB (or plume) environments. MORB correlations are parallel to, and at lower Nb/Y ratios than, Iceland basalt correlations. This is expressed by a discrimination parameter defined as Delta Nb = 1.74 + log(Nb/Y) - 1.92 log(Zr/Y). N-MORB have negative Delta-Nb values, whereas Iceland and other OIBs have positive values. Fitton et al. interpret this in terms of a niobium deficiency in MORB that is balanced by a Nb excess in OIBs. This interpretation conflicts with evidence based on Nb/U ratios (Hofmann et al., 1986), that MORB and OIB are parts of a common reservoir, which is different from, and complementary to, the continental crust. Both parts of this MORB-OIB reservoir are characterized by higher-than-primitive Nb/U and Nb/Th ratios, whereas continental crust has dramatically lower Nb/U and Nb/Th ratios. The use of VICE/MICE (very-incompatible- element to moderately-incompatible-element) ratios, such as Nb/Y, obscures this. The significance of the VICE/MICE plot becomes clear if one replaces Nb by other VICEs in the log(Nb/Y)-log(Zr/Y) plot. This shows that any of these VICEs yield similar topologies as Nb/Y. Thus for a given Zr/Y ratio, depleted MORB have consistently lower Ba/Y, Th/Y, and La/Y ratios than do Iceland basalts, even the most incompatible-element- depleted Iceland picrites. This is caused by a less extreme depletion of Icelandic picrites (and tholeiites) in VICEs relative to Y, causing their spidergram patterns to be flatter than those of depleted MORB, which "drop off" more steeply. The important point is that there is no special Nb effect. The difference between Iceland-style and MORB-style depletion might therefore be called "Delta VICE" rather than "Delta Niobium." This assessment of Nb geochemistry is confirmed by new compilations for several MORB and OIB suites, which shows that in some of these suites, Nb and Th yield the most uniform ratios, whereas Nb/U is more uniform in others (including Iceland). Similarly, Ta is similar to Nb in some suites, whereas it is slightly more compatible than Nb in others. These slight regional differences are of minor consequence in the present context. The cause of the greater depletion in VICEs relative to MICEs in N-MORB compared with the most depleted Icelandic is most likely related to the roles of garnet and clinopyroxene during source depletion processes.

Performance of multi-aperture grid extraction systems for an ITER-relevant RF-driven negative hydrogen ion source

NASA Astrophysics Data System (ADS)

Franzen, P.; Gutser, R.; Fantz, U.; Kraus, W.; Falter, H.; Fröschle, M.; Heinemann, B.; McNeely, P.; Nocentini, R.; Riedl, R.; Stäbler, A.; Wünderlich, D.

2011-07-01

The ITER neutral beam system requires a negative hydrogen ion beam of 48 A with an energy of 0.87 MeV, and a negative deuterium beam of 40 A with an energy of 1 MeV. The beam is extracted from a large ion source of dimension 1.9 × 0.9 m2 by an acceleration system consisting of seven grids with 1280 apertures each. Currently, apertures with a diameter of 14 mm in the first grid are foreseen. In 2007, the IPP RF source was chosen as the ITER reference source due to its reduced maintenance compared with arc-driven sources and the successful development at the BATMAN test facility of being equipped with the small IPP prototype RF source ( {\\sim}\\frac{1}{8} of the area of the ITER NBI source). These results, however, were obtained with an extraction system with 8 mm diameter apertures. This paper reports on the comparison of the source performance at BATMAN of an ITER-relevant extraction system equipped with chamfered apertures with a 14 mm diameter and 8 mm diameter aperture extraction system. The most important result is that there is almost no difference in the achieved current density—being consistent with ion trajectory calculations—and the amount of co-extracted electrons. Furthermore, some aspects of the beam optics of both extraction systems are discussed.

Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments

NASA Astrophysics Data System (ADS)

Waltz, R. E.; Bass, E. M.; Heidbrink, W. W.; VanZeeland, M. A.

2015-11-01

Recent experiments with the DIII-D tilted neutral beam injection (NBI) varying the beam energetic particle (EP) source profiles have provided strong evidence that unstable Alfven eigenmodes (AE) drive stiff EP transport at a critical EP density gradient [Heidbrink et al 2013 Nucl. Fusion 53 093006]. Here the critical gradient is identified by the local AE growth rate being equal to the local ITG/TEM growth rate at the same low toroidal mode number. The growth rates are taken from the gyrokinetic code GYRO. Simulation show that the slowing down beam-like EP distribution has a slightly lower critical gradient than the Maxwellian. The ALPHA EP density transport code [Waltz and Bass 2014 Nucl. Fusion 54 104006], used to validate the model, combines the low-n stiff EP critical density gradient AE mid-core transport with the Angioni et al (2009 Nucl. Fusion 49 055013) energy independent high-n ITG/TEM density transport model controling the central core EP density profile. For the on-axis NBI heated DIII-D shot 146102, while the net loss to the edge is small, about half the birth fast ions are transported from the central core r/a  <  0.5 and the central density is about half the slowing down density. These results are in good agreement with experimental fast ion pressure profiles inferred from MSE constrained EFIT equilibria.

[Effect of vanadium exposure on neurobehavioral function in workers].

PubMed

Zhu, C W; Liu, Y X; Huang, C J; Gao, W; Hu, G L; Li, J; Zhang, Q; Lan, Y J

2016-02-20

To establish the comprehensive indicators for neurobehavioral function test, and to investigate the possible adverse effect of long-time vanadium exposure on neurobehavioral function and its features in workers. From July to November, 2012, The Neurobehavioral Core Test Battery(NCTB) recommended by WHO was used to conduct tests for 128 workers in vanadium exposure group and 128 workers in control group. The t-test and analysis of covariance were used to compare the differences in each indicator in NCTB between different populations, and the principal component analysis was used to establish the comprehensive neurobehavioral index(NBI) and investigate the effect of vanadium on workers' neurobehavioral function. The vanadium exposure group had significantly lower visual retention score(6.9±1.9), digit span(order) score(8.9±2.9), lifting and turning dexterity(the non-handed hand) score (14.1±3.6), pursuit aiming test(the number of correct dots) score(65.7±24.8), and digit symbol score (31.1±15.0) than the control group (8.2±1.3, 9.4±2.7, 15.5±3.0, 76.5±23.8, and 33.7±9.5)(all P<0.05). The vanadium exposure group also had a significantly lower NBI than the control group(-0.167±0.602 vs 0.168±0.564, P<0.05). Long-term vanadium exposure can influence the workers' neurobehavioral function, with the manifestations of decreased hearing and visual memory, movement velocity, accuracy, and coordination.

Effect of toroidal field ripple on plasma rotation in JET

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Vries, P.; Salmi, A.; Parail, V.

Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude ( ) from an average value of M = 0.40 0.55 for operations at the standard JET ripple of = 0.08% to M = 0.25 0.40 for = 0.5% and M = 0.1 0.3 for = 1%. TF ripple effectsmore » should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes ( ~ 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect.« less

Density and beta limits in the Madison Symmetric Torus Reversed-Field Pinch

NASA Astrophysics Data System (ADS)

Caspary, Kyle Jonathan

Operational limits and the underlying physics are explored on the Madison Symmetric Torus (MST) Reversed-Field Pinch (RFP) using deuterium pellet fueling. The injection of a fast pellet provides a large source of fuel in the plasma edge upon impact with the vessel wall, capable of triggering density limit terminations for the full range of plasma current, up to 600 kA. As the pellet size and plasma density increase, approaching the empirical Greenwald limit, plasma degradation is observed in the form of current decay, increased magnetic activity in the edge and core, increased radiation and plasma cooling. The complete termination of the plasma is consistent with the Greenwald limit; however, a slightly smaller maximum density is observed in discharges without toroidal field reversal. The plasma beta is the ratio of the plasma pressure to the confining magnetic pressure. Beta limits are known to constrain other magnetic confinement devices, but no beta limit has yet been established on the RFP. On MST, the highest beta values are obtained in improved confinement discharges with pellet fueling. By using pellet injection to scan the plasma density during PPCD, we also achieve a scan of Ohmic input power due to the increase in plasma resistivity. We observe a factor of 3 or more increase in Ohmic power as we increase the density from 1*1019 to 3*10 19 m-3. Despite this increased Ohmic power, the electron contribution to beta is constant, suggesting a confinement limited beta for the RFP. The electrons and ions are classically well coupled in these cold, dense pellet fueled plasmas, so the increase in total beta at higher density is primarily due to the increased ion contribution. The interaction of pellet fueling and NBI heating is explored. Modeling of MST's neutral heating beam suggests an optimal density for beam power deposition of 2-3*1019 m-3. Low current, NBI heated discharges show evidence of an increased electron beta in this density range. Additionally, the fast ion population can enhance ablation as well as cause pellet deflection. Other exploratory experiments with the pellet injection system explore additional injection scenarios and expand the injector capabilities.

Determination of structural, mechanical and corrosion properties of Nb2O5 and (NbyCu 1-y)Ox thin films deposited on Ti6Al4V alloy substrates for dental implant applications.

PubMed

Mazur, M; Kalisz, M; Wojcieszak, D; Grobelny, M; Mazur, P; Kaczmarek, D; Domaradzki, J

2015-02-01

In this paper comparative studies on the structural, mechanical and corrosion properties of Nb2O5/Ti and (NbyCu1-y)Ox/Ti alloy systems have been investigated. Pure layers of niobia and niobia with a copper addition were deposited on a Ti6Al4V titanium alloy surface using the magnetron sputtering method. The physicochemical properties of the prepared thin films were examined with the aid of XRD, XPS SEM and AFM measurements. The mechanical properties (i.e., nanohardness, Young's modulus and abrasion resistance) were performed using nanoindentation and a steel wool test. The corrosion properties of the coatings were determined by analysis of the voltammetric curves. The deposited coatings were crack free, exhibited good adherence to the substrate, no discontinuity of the thin film was observed and the surface morphology was homogeneous. The hardness of pure niobium pentoxide was ca. 8.64GPa. The obtained results showed that the addition of copper into pure niobia resulted in the preparation of a layer with a lower hardness of ca. 7.79 GPa (for niobia with 17 at.% Cu) and 7.75 GPa (for niobia with 25 at.% Cu). The corrosion properties of the tested thin films deposited on the surface of titanium alloy depended on the composition of the thin layer. The addition of copper (i.e. a noble metal) to Nb2O5 film increased the corrosion resistance followed by a significant decrease in the value of corrosion currents and, in case of the highest Cu content, the shift of corrosion potential towards the noble direction. The best corrosion properties were obtained from a sample of Ti6Al4V coated with (Nb0.75Cu0.25)Ox thin film. It seems that the tested materials could be used in the future as protection coatings for Ti alloys in biomedical applications such as implants. Copyright © 2014. Published by Elsevier B.V.

Prospects for Alpha Particle Heating in JET in the Hot Ion Regime

NASA Astrophysics Data System (ADS)

Cordey, J. G.; Keilhacker, M.; Watkins, M. L.

1987-01-01

The prospects for alpha particle heating in JET are discussed. A computational model is developed to represent adequately the neutron yield from JET plasmas heated by neutral beam injection. This neutral beam model, augmented by a simple plasma model, is then used to determine the neutron yields and fusion Q-values anticipated for different heating schemes in future operation of JET with tritium. The relative importance of beam-thermal and thermal-thermal reactions is pointed out and the dependence of the results on, for example, plasma density, temperature, energy confinement and purity is shown. Full 1½-D transport code calculations, based on models developed for ohmic, ICRF and NBI heated JET discharges, are used also to provide a power scan for JET operation in tritium in the low density, high ion temperature regime. The results are shown to be in good agreement with the estimates made using the simple plasma model and indicate that, based on present knowledge, a fusion Q-value in the plasma centre above unity should be achieved in JET.

A novel approach of an absolute coding pattern based on Hamiltonian graph

NASA Astrophysics Data System (ADS)

Wang, Ya'nan; Wang, Huawei; Hao, Fusheng; Liu, Liqiang

2017-02-01

In this paper, a novel approach of an optical type absolute rotary encoder coding pattern is presented. The concept is based on the principle of the absolute encoder to find out a unique sequence that ensures an unambiguous shaft position of any angular. We design a single-ring and a n-by-2 matrix absolute encoder coding pattern by using the variations of Hamiltonian graph principle. 12 encoding bits is used in the single-ring by a linear array CCD to achieve an 1080-position cycle encoding. Besides, a 2-by-2 matrix is used as an unit in the 2-track disk to achieve a 16-bits encoding pattern by using an area array CCD sensor (as a sample). Finally, a higher resolution can be gained by an electronic subdivision of the signals. Compared with the conventional gray or binary code pattern (for a 2n resolution), this new pattern has a higher resolution (2n*n) with less coding tracks, which means the new pattern can lead to a smaller encoder, which is essential in the industrial production.

Development of an energy analyzer as diagnostic of beam-generated plasma in negative ion beam systems

NASA Astrophysics Data System (ADS)

Sartori, E.; Carozzi, G.; Veltri, P.; Spolaore, M.; Cavazzana, R.; Antoni, V.; Serianni, G.

2017-08-01

The measurement of the plasma potential and the energy spectrum of secondary particles in the drift region of a negative ion beam offers an insight into beam-induced plasma formation and beam transport in low pressure gasses. Plasma formation in negative-ion beam systems, and the characteristics of such a plasma are of interest especially for space charge compensation, plasma formation in neutralizers, and the development of improved schemes of beam-induced plasma neutralisers for future fusion devices. All these aspects have direct implications in the ITER Heating Neutral Beam and the operation of the prototypes, SPIDER and MITICA, and also have important role in the conceptual studies for NBI systems of DEMO, while at present experimental data are lacking. In this paper we present the design and development of an ion energy analyzer to measure the beam plasma formation and space charge compensation in negative ion beams. The diagnostic is a retarding field energy analyzer (RFEA), and will measure the transverse energy spectra of plasma molecular ions. The calculations that supported the design are reported, and a method to interpret the measurements in negative ion beam systems is also proposed. Finally, the experimental results of the first test in a magnetron plasma are presented.

From local spectral measurements to maps of vegetation cover and biomass on the Qinghai-Tibet-Plateau: Do we need hyperspectral information?

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Nauss, Thomas; Bendix, Jörg

2017-03-01

Though the relevance of pasture degradation on the Qinghai-Tibet Plateau (QTP) is widely postulated, its extent is still unknown. Due to the enormous spatial extent, remote sensing provides the only possibility to investigate pasture degradation via frequently used proxies such as vegetation cover and aboveground biomass (AGB). However, unified remote sensing approaches are still lacking. This study tests the applicability of hyper- and multispectral in situ measurements to map vegetation cover and AGB on regional scales. Using machine learning techniques, it is tested whether the full hyperspectral information is needed or if multispectral information is sufficient to accurately estimate pasture degradation proxies. To regionalize pasture degradation proxies, the transferability of the locally derived ML-models to high resolution multispectral satellite data is assessed. 1183 hyperspectral measurements and vegetation records were performed at 18 locations on the QTP. Random Forests models with recursive feature selection were trained to estimate vegetation cover and AGB using narrow-band indices (NBI) as predictors. Separate models were calculated using NBI from hyperspectral data as well as from the same data resampled to WorldView-2, QuickBird and RapidEye channels. The hyperspectral results were compared to the multispectral results. Finally, the models were applied to satellite data to map vegetation cover and AGB on a regional scale. Vegetation cover was accurately predicted by Random Forest if hyperspectral measurements were used (cross validated R2 = 0.89). In contrast, errors in AGB estimations were considerably higher (cross validated R2 = 0.32). Only small differences in accuracy were observed between the models based on hyperspectral compared to multispectral data. The application of the models to satellite images generally resulted in an increase of the estimation error. Though this reflects the challenge of applying in situ measurements to satellite data, the results still show a high potential to map pasture degradation proxies on the QTP. Thus, this study presents robust methodology to remotely detect and monitor pasture degradation at high spatial resolutions.

Terahertz imaging with compressive sensing

NASA Astrophysics Data System (ADS)

Chan, Wai Lam

Most existing terahertz imaging systems are generally limited by slow image acquisition due to mechanical raster scanning. Other systems using focal plane detector arrays can acquire images in real time, but are either too costly or limited by low sensitivity in the terahertz frequency range. To design faster and more cost-effective terahertz imaging systems, the first part of this thesis proposes two new terahertz imaging schemes based on compressive sensing (CS). Both schemes can acquire amplitude and phase-contrast images efficiently with a single-pixel detector, thanks to the powerful CS algorithms which enable the reconstruction of N-by- N pixel images with much fewer than N2 measurements. The first CS Fourier imaging approach successfully reconstructs a 64x64 image of an object with pixel size 1.4 mm using a randomly chosen subset of the 4096 pixels which defines the image in the Fourier plane. Only about 12% of the pixels are required for reassembling the image of a selected object, equivalent to a 2/3 reduction in acquisition time. The second approach is single-pixel CS imaging, which uses a series of random masks for acquisition. Besides speeding up acquisition with a reduced number of measurements, the single-pixel system can further cut down acquisition time by electrical or optical spatial modulation of random patterns. In order to switch between random patterns at high speed in the single-pixel imaging system, the second part of this thesis implements a multi-pixel electrical spatial modulator for terahertz beams using active terahertz metamaterials. The first generation of this device consists of a 4x4 pixel array, where each pixel is an array of sub-wavelength-sized split-ring resonator elements fabricated on a semiconductor substrate, and is independently controlled by applying an external voltage. The spatial modulator has a uniform modulation depth of around 40 percent across all pixels, and negligible crosstalk, at the resonant frequency. The second-generation spatial terahertz modulator, also based on metamaterials with a higher resolution (32x32), is under development. A FPGA-based circuit is designed to control the large number of modulator pixels. Once fully implemented, this second-generation device will enable fast terahertz imaging with both pulsed and continuous-wave terahertz sources.

VMAT2 Inhibitors and the Path to Ingrezza (Valbenazine).

PubMed

Harriott, Nicole D; Williams, John P; Smith, Evan B; Bozigian, Haig P; Grigoriadis, Dimitri E

2018-01-01

The dopaminergic system plays a key role in the central nervous system, regulating executive function, arousal, reward, and motor control. Dysregulation of this critical monoaminergic system has been associated with diseases of the central nervous system including schizophrenia, Parkinson's disease, and disorders such as attention deficit hyperactivity disorders and addiction. Drugs that modify the dopaminergic system by modulating the activity of dopamine have been successful in demonstrating clinical efficacy by providing treatments for these diseases. Specifically, antipsychotics, both typical and atypical, while acting on a number of monoaminergic systems in the brain, primarily target the dopamine system via inhibition of postsynaptic dopamine receptors. The vesicular monoamine transporter 2 (VMAT2) is an integral presynaptic protein that regulates the packaging and subsequent release of dopamine and other monoamines from neuronal vesicles into the synapse. Despite acting on opposing sides of the synapse, both antipsychotics and VMAT2 inhibitors act to decrease the activity of central dopaminergic systems. Tardive dyskinesia is a disorder characterized by involuntary repetitive movements and thought to be a result of a hyperdopaminergic state precipitated by the use of antipsychotics. Valbenazine (NBI-98854), a novel compound that selectively inhibits VMAT2 through an active metabolite, has been developed for the treatment of tardive dyskinesia and is the first drug approved for the treatment of this disorder. This chapter describes the process leading to the discovery of valbenazine, its pharmacological characteristics, along with preclinical and clinical evidence of its efficacy. © 2018 Elsevier B.V. All rights reserved.

Stable “Trait” Variance of Temperament as a Predictor of the Temporal Course of Depression and Social Phobia

PubMed Central

Naragon-Gainey, Kristin; Gallagher, Matthew W.; Brown, Timothy A.

2013-01-01

A large body of research has found robust associations between dimensions of temperament (e.g., neuroticism, extraversion) and the mood and anxiety disorders. However, mood-state distortion (i.e., the tendency for current mood state to bias ratings of temperament) likely confounds these associations, rendering their interpretation and validity unclear. This issue is of particular relevance to clinical populations who experience elevated levels of general distress. The current study used the “trait-state-occasion” latent variable model (Cole, Martin, & Steiger, 2005) to separate the stable components of temperament from transient, situational influences such as current mood state. We examined the predictive power of the time-invariant components of temperament on the course of depression and social phobia in a large, treatment-seeking sample with mood and/or anxiety disorders (N = 826). Participants were assessed three times over the course of one year, using interview and self-report measures; most participants received treatment during this time. Results indicated that both neuroticism/behavioral inhibition (N/BI) and behavioral activation/positive affect (BA/P) consisted largely of stable, time-invariant variance (57% to 78% of total variance). Furthermore, the time-invariant components of N/BI and BA/P were uniquely and incrementally predictive of change in depression and social phobia, adjusting for initial symptom levels. These results suggest that the removal of state variance bolsters the effect of temperament on psychopathology among clinically distressed individuals. Implications for temperament-psychopathology models, psychopathology assessment, and the stability of traits are discussed. PMID:24016004

Experimental challenges to stiffness as a transport paradigm

DOE PAGES

Luce, Timothy C.; Burrell, Keith H.; Holland, Christopher; ...

2018-01-04

Two power scans were carried out in H-mode plasmas in DIII-D; one employed standard co-current neutral beam injection (NBI), while the other used a mixture of co-current and counter-current NBI to scan power while holding the torque to a low fixed value. Analysis of the ion and electron heat transport, ion toroidal angular momentum transport, and thermal deuterium transport from these scans are presented. Invariance of the gradients or gradient scalelengths, as might be expected from stiff transport, was not generally observed. When invariance was seen, it was not accompanied by a strong increase in transport, except in the casemore » of the absolute deuterium ion transport. Conduction in the ion channel is the dominant energy loss mechanism. The variation of the ion heat transport with applied power is similar for the co-injection and fixed torque scans, indicating that ExB shearing is not determining the plasma response to additional power. There is however, a quantitative difference in the transport between the two scans, indicating ExB shearing does play a role in the transport. Comparison of these results with a previous experiment that directly probed stiffness at a single radius leads to the following conclusion: while local stiffness as formally defined may hold, invariance of the gradients or normalized scalelengths does not follow from stiff transport in more practical scaling experiments, such as the power scans discussed here. Lastly, possible reasons for the lack of correspondence between the local picture and the global expectations are discussed.« less

Experimental challenges to stiffness as a transport paradigm

NASA Astrophysics Data System (ADS)

Luce, T. C.; Burrell, K. H.; Holland, C.; Marinoni, A.; Petty, C. C.; Smith, S. P.; Austin, M. E.; Grierson, B. A.; Zeng, L.

2018-02-01

Two power scans were carried out in H-mode plasmas in DIII-D; one employed standard co-current neutral beam injection (NBI), while the other used a mixture of co-current and counter-current NBI to scan power while holding the torque to a low fixed value. Analysis of the ion and electron heat transport, ion toroidal angular momentum transport, and thermal deuterium transport from these scans is presented. Invariance of the gradients or gradient scalelengths, as might be expected from stiff transport, was not generally observed. When invariance was seen, it was not accompanied by a strong increase in transport, except in the case of the absolute deuterium ion transport. Conduction in the ion channel is the dominant energy loss mechanism. The variation of the ion heat transport with applied power is similar for the co-injection and fixed torque scans, indicating that E  ×  B shearing is not determining the plasma response to additional power. There is however, a quantitative difference in the transport between the two scans, indicating E  ×  B shearing does play a role in the transport. Comparison of these results with a previous experiment that directly probed stiffness at a single radius leads to the following conclusion: while local stiffness as formally defined may hold, invariance of the gradients or normalized scalelengths does not follow from stiff transport in more practical scaling experiments, such as the power scans discussed here. Possible reasons for the lack of correspondence between the local picture and the global expectations are discussed.

Electromagnetic characteristics of geodesic acoustic mode in the COMPASS tokamak

NASA Astrophysics Data System (ADS)

Seidl, J.; Krbec, J.; Hron, M.; Adamek, J.; Hidalgo, C.; Markovic, T.; Melnikov, A. V.; Stockel, J.; Weinzettl, V.; Aftanas, M.; Bilkova, P.; Bogar, O.; Bohm, P.; Eliseev, L. G.; Hacek, P.; Havlicek, J.; Horacek, J.; Imrisek, M.; Kovarik, K.; Mitosinkova, K.; Panek, R.; Tomes, M.; Vondracek, P.

2017-12-01

Axisymmetric geodesic acoustic mode (GAM) oscillations of the magnetic field, plasma potential and electron temperature have been identified on the COMPASS tokamak. This work brings an overview of their electromagnetic properties studied by multi-pin reciprocating probes and magnetic diagnostics. The n  =  0 fluctuations form a continuous spectrum in limited plasmas but change to a single dominant peak in diverted configuration. At the edge of diverted plasmas the mode exhibits a non-local structure with a constant frequency over a radial extent of at least several centimeters. Nevertheless, the frequency still reacts on temporal changes of plasma temperature caused by an auxiliary NBI heating as well as those induced by periodic sawtooth crashes. Radial wavelength of the mode is found to be about 1-4 cm, with values larger for the plasma potential than for the electron temperature. The mode propagates radially outward and its radial structure induces oscillations of a poloidal E  ×  B velocity, that can locally reach the level of the mean poloidal flow. Bicoherence analysis confirms a non-linear interaction of GAM with a broadband ambient turbulence. The mode exhibits strong axisymmetric magnetic oscillations that are studied both in the poloidal and radial components of the magnetic field. Their poloidal standing-wave structure was confirmed and described for the first time in diverted plasmas. In limited plasmas their amplitude scales with safety factor. Strong suppression of the magnetic GAM component, and possibly of GAM itself, is observed during co-current but not counter-current NBI.

Stable "trait" variance of temperament as a predictor of the temporal course of depression and social phobia.

PubMed

Naragon-Gainey, Kristin; Gallagher, Matthew W; Brown, Timothy A

2013-08-01

A large body of research has found robust associations between dimensions of temperament (e.g., neuroticism, extraversion) and the mood and anxiety disorders. However, mood-state distortion (i.e., the tendency for current mood state to bias ratings of temperament) likely confounds these associations, rendering their interpretation and validity unclear. This issue is of particular relevance to clinical populations who experience elevated levels of general distress. The current study used the "trait-state-occasion" latent variable model (D. A. Cole, N. C. Martin, & J. H. Steiger, 2005) to separate the stable components of temperament from transient, situational influences such as current mood state. We examined the predictive power of the time-invariant components of temperament on the course of depression and social phobia in a large, treatment-seeking sample with mood and/or anxiety disorders (N = 826). Participants were assessed 3 times over the course of 1 year, using interview and self-report measures; most participants received treatment during this time. Results indicated that both neuroticism/behavioral inhibition (N/BI) and behavioral activation/positive affect (BA/P) consisted largely of stable, time-invariant variance (57% to 78% of total variance). Furthermore, the time-invariant components of N/BI and BA/P were uniquely and incrementally predictive of change in depression and social phobia, adjusting for initial symptom levels. These results suggest that the removal of state variance bolsters the effect of temperament on psychopathology among clinically distressed individuals. Implications for temperament-psychopathology models, psychopathology assessment, and the stability of traits are discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Experimental challenges to stiffness as a transport paradigm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luce, Timothy C.; Burrell, Keith H.; Holland, Christopher

Two power scans were carried out in H-mode plasmas in DIII-D; one employed standard co-current neutral beam injection (NBI), while the other used a mixture of co-current and counter-current NBI to scan power while holding the torque to a low fixed value. Analysis of the ion and electron heat transport, ion toroidal angular momentum transport, and thermal deuterium transport from these scans are presented. Invariance of the gradients or gradient scalelengths, as might be expected from stiff transport, was not generally observed. When invariance was seen, it was not accompanied by a strong increase in transport, except in the casemore » of the absolute deuterium ion transport. Conduction in the ion channel is the dominant energy loss mechanism. The variation of the ion heat transport with applied power is similar for the co-injection and fixed torque scans, indicating that ExB shearing is not determining the plasma response to additional power. There is however, a quantitative difference in the transport between the two scans, indicating ExB shearing does play a role in the transport. Comparison of these results with a previous experiment that directly probed stiffness at a single radius leads to the following conclusion: while local stiffness as formally defined may hold, invariance of the gradients or normalized scalelengths does not follow from stiff transport in more practical scaling experiments, such as the power scans discussed here. Lastly, possible reasons for the lack of correspondence between the local picture and the global expectations are discussed.« less

Divertor scenario development for NSTX Upgrade

NASA Astrophysics Data System (ADS)

Soukhanovskii, V. A.; McLean, A. G.; Meier, E. T.; Rognlien, T. D.; Ryutov, D. D.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kaita, R.; Kolemen, E.; Leblanc, B. P.; Menard, J. E.; Podesta, M.; Scotti, F.

2012-10-01

In the NSTX-U tokamak, initial plans for divertor plasma-facing components (PFCs) include lithium and boron coated graphite, with a staged transition to molybdenum. Steady-state peak divertor heat fluxes are projected to reach 20-30 MW/m^2 in 2 MA, 12 MW NBI-heated discharges of up to 5 s duration, thus challenging PFC thermal limits. Based on the recent NSTX divertor experiments and modeling with edge transport code UEDGE, a favorable basis for divertor power handling in NSTX-U is developed. The snowflake divertor geometry and feedback-controlled divertor impurity seeding applied to the lower and upper divertors are presently envisioned. In the NSTX snowflake experiments with lithium-coated graphite PFCs, the peak divertor heat fluxes from Type I ELMs and between ELMs were significantly reduced due to geometry effects, increased volumetric losses and null-point convective redistribution between strike points. H-mode core confinement was maintained at H98(y,2)<=1 albeit the radiative detachment. Additional CD4 seeding demonstrated potential for a further increase of divertor radiation.

Hf-Nd isotope constraints on the origin of the Cretaceous Caribbean plateau and its relationship to the Galápagos plume

NASA Astrophysics Data System (ADS)

Thompson, P. M. E.; Kempton, P. D.; White, R. V.; Kerr, A. C.; Tarney, J.; Saunders, A. D.; Fitton, J. G.; McBirney, A.

2004-01-01

Formation of the Cretaceous Caribbean plateau, including the komatiites of Gorgona, has been linked to the currently active Galápagos hotspot. We use Hf-Nd isotopes and trace element data to characterise both the Caribbean plateau and the Galápagos hotspot, and to investigate the relationship between them. Four geochemical components are identified in the Galápagos mantle plume: two 'enriched' components with ɛHf and ɛNd similar to enriched components observed in other mantle plumes, one moderately enriched component with high Nb/Y, and a fourth component which most likely represents depleted MORB source mantle. The Caribbean plateau basalt data form a linear array in Hf-Nd isotope space, consistent with mixing between two mantle components. Combined Hf-Nd-Pb-Sr-He isotope and trace element data from this study and the literature suggest that the more enriched Caribbean end member corresponds to one or both of the enriched components identified on Galápagos. Likewise, the depleted end member of the array is geochemically indistinguishable from MORB and corresponds to the depleted component of the Galápagos system. Enriched basalts from Gorgona partially overlap with the Caribbean plateau array in ɛHf vs. ɛNd, whereas depleted basalts, picrites and komatiites from Gorgona have a high ɛHf for a given ɛNd, defining a high- ɛHf depleted end member that is not observed elsewhere within the Caribbean plateau sequences. This component is similar, however, in terms of Hf-Nd-Pb-He isotopes and trace elements to the depleted plume component recognised in basalts from Iceland and along the Reykjanes Ridge. We suggest that the Caribbean plateau represents the initial outpourings of the ancestral Galápagos plume. Absence of a moderately enriched, high Nb/Y component in the older Caribbean plateau (but found today on the island of Floreana) is either due to changing source compositions of the plume over its 90 Ma history, or is an artifact of limited sampling. The high- ɛHf depleted component sampled by the Gorgona komatiites and depleted basalts is unique to Gorgona and is not found in the Caribbean plateau. This may be an indication of the scale of heterogeneity of the Caribbean plateau system; alternatively Gorgona may represent a separate oceanic plateau derived from a completely different Pacific plume, such as the Sala y Gomez.

Electron temperature and heat load measurements in the COMPASS divertor using the new system of probes

NASA Astrophysics Data System (ADS)

Adamek, J.; Seidl, J.; Horacek, J.; Komm, M.; Eich, T.; Panek, R.; Cavalier, J.; Devitre, A.; Peterka, M.; Vondracek, P.; Stöckel, J.; Sestak, D.; Grover, O.; Bilkova, P.; Böhm, P.; Varju, J.; Havranek, A.; Weinzettl, V.; Lovell, J.; Dimitrova, M.; Mitosinkova, K.; Dejarnac, R.; Hron, M.; The COMPASS Team; The EUROfusion MST1 Team

2017-11-01

A new system of probes was recently installed in the divertor of tokamak COMPASS in order to investigate the ELM energy density with high spatial and temporal resolution. The new system consists of two arrays of rooftop-shaped Langmuir probes (LPs) used to measure the floating potential or the ion saturation current density and one array of Ball-pen probes (BPPs) used to measure the plasma potential with a spatial resolution of ~3.5 mm. The combination of floating BPPs and LPs yields the electron temperature with microsecond temporal resolution. We report on the design of the new divertor probe arrays and first results of electron temperature profile measurements in ELMy H-mode and L-mode. We also present comparative measurements of the parallel heat flux using the new probe arrays and fast infrared termography (IR) data during L-mode with excellent agreement between both techniques using a heat power transmission coefficient γ  =  7. The ELM energy density {{\\varepsilon }\\parallel } was measured during a set of NBI assisted ELMy H-mode discharges. The peak values of {{\\varepsilon }\\parallel } were compared with those predicted by model and with experimental data from JET, AUG and MAST with a good agreement.

Research on Turbine Flowfield Analysis Methods.

DTIC Science & Technology

1985-01-01

Z W 2 N 312 ZClC(NP)=(Z7A1(NP)+Z- A2(NP),*2-W)/Z. 72:’ 3 l=2,NB.2 SNP =NBI2+I ZB-B=(Z-AI(NP2-NP)iZA2(NP--NIP)*ZW)/2. 31𔃽 Z’CC’(NP)=CONJG(ZBB) =REAL (C...AD-RI64 179 RESEARCH ON TURBINE FLOUFIELD ANALYSIS NETHODSCU) 1/2 CALSPAN ADYANCED TECHNOLOGY CENTER BUFFALO NY U J RAE JAN 85 CALSPAN-?177 A 3 AFOSR...MARKINGS %. ft UNCLASSIFIED _ _ _ _ _ _ _ 4 2&. SECURITY CLASSIFICATION AUTHORITY 3 . DISTRIBUTION/AVAI LABILITY OF REPORT * 2. OCLASIFCATON/OWNRAONG

Symposium on Molecular Spectroscopy (44th) Held in Columbus, Ohio on 12- 16 June 1989

DTIC Science & Technology

1989-06-01

California, 94025. FC4. A PARTIAL DIFFERENTIAL EQUATION FOR THE RKR INTEGRAL ........................ 15 min.(9:21) D. L. HUESTIS, Molecular Physics...above have been analyzed further. We define effective constants by the following equations : Beff(v4 ,o) - B - B + nb(i/2)<cos(67)> + b<P72 > DJeff(v4...a) - D J - DJ + ndj(l/2)<cos(6j)> +edj<P72> D J K - D J K + "djk(l/2)<cos(6y)> + djk<Py 2>. In these equations , <..> are the diagonal values of

Rapid and sensitive detection of early esophageal squamous cell carcinoma with fluorescence probe targeting dipeptidylpeptidase IV

PubMed Central

Onoyama, Haruna; Kamiya, Mako; Kuriki, Yugo; Komatsu, Toru; Abe, Hiroyuki; Tsuji, Yosuke; Yagi, Koichi; Yamagata, Yukinori; Aikou, Susumu; Nishida, Masato; Mori, Kazuhiko; Yamashita, Hiroharu; Fujishiro, Mitsuhiro; Nomura, Sachiyo; Shimizu, Nobuyuki; Fukayama, Masashi; Koike, Kazuhiko; Urano, Yasuteru; Seto, Yasuyuki

2016-01-01

Early detection of esophageal squamous cell carcinoma (ESCC) is an important prognosticator, but is difficult to achieve by conventional endoscopy. Conventional lugol chromoendoscopy and equipment-based image-enhanced endoscopy, such as narrow-band imaging (NBI), have various practical limitations. Since fluorescence-based visualization is considered a promising approach, we aimed to develop an activatable fluorescence probe to visualize ESCCs. First, based on the fact that various aminopeptidase activities are elevated in cancer, we screened freshly resected specimens from patients with a series of aminopeptidase-activatable fluorescence probes. The results indicated that dipeptidylpeptidase IV (DPP-IV) is specifically activated in ESCCs, and would be a suitable molecular target for detection of esophageal cancer. Therefore, we designed, synthesized and characterized a series of DPP-IV-activatable fluorescence probes. When the selected probe was topically sprayed onto endoscopic submucosal dissection (ESD) or surgical specimens, tumors were visualized within 5 min, and when the probe was sprayed on biopsy samples, the sensitivity, specificity and accuracy reached 96.9%, 85.7% and 90.5%. We believe that DPP-IV-targeted activatable fluorescence probes are practically translatable as convenient tools for clinical application to enable rapid and accurate diagnosis of early esophageal cancer during endoscopic or surgical procedures. PMID:27245876

H-mode fueling optimization with the supersonic deuterium jet in NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soukhanovskii, V A; Bell, M G; Bell, R E

2008-06-18

High-performance, long-pulse 0.7-1.2 MA 6-7 MW NBI-heated small-ELM H-mode plasma discharges are developed in the National Spherical Torus Experiment (NSTX) as prototypes for confinement and current drive extrapolations to future spherical tori. It is envisioned that innovative lithium coating techniques for H-mode density pumping and a supersonic deuterium jet for plasma refueling will be used to achieve the low pedestal collisionality and low n{sub e}/n{sub G} fractions (0.3-0.6), both of which being essential conditions for maximizing the non-inductive (bootstrap and beam driven) current fractions. The low field side supersonic gas injector (SGI) on NSTX consists of a small converging-diverging graphitemore » Laval nozzle and a piezoelectric gas valve. The nozzle is capable of producing a deuterium jet with Mach number M {le} 4, estimated gas density at the nozzle exit n {le} 5 x 10{sup 23} m{sup -3}, estimated temperature T {ge} 70 K, and flow velocity v = 2:4 km/s. The nozzle Reynolds number Reis {approx_equal} 6000. The nozzle and the valve are enclosed in a protective carbon fiber composite shroud and mounted on a movable probe at a midplane port location. Despite the beneficial L-mode fueling experience with supersonic jets in limiter tokamaks, there is a limited experience with fueling of high-performance H-mode divertor discharges and the associated density, MHD stability, and MARFE limits. In initial supersonic deuterium jet fueling experiments in NSTX, a reliable H-mode access, a low NBI power threshold, P{sub LH} {le} 2 MW, and a high fueling efficiency (0.1-0.4) have been demonstrated. Progress has also been made toward a better control of the injected fueling gas by decreasing the uncontrolled high field side (HFS) injector fueling rate by up to 95 % and complementing it with the supersonic jet fueling. These results motivated recent upgrades to the SGI gas delivery and control systems. The new SGI-Upgrade (SGI-U) capabilities include multi-pulse ms-scale controls and a reservoir gas pressure up to P{sub 0} = 5000 Torr. In this paper we summarize recent progress toward optimization of H-mode fueling in NSTX using the SGI-U.« less

Automatic Detection and Classification of Colorectal Polyps by Transferring Low-Level CNN Features From Nonmedical Domain.

PubMed

Zhang, Ruikai; Zheng, Yali; Mak, Tony Wing Chung; Yu, Ruoxi; Wong, Sunny H; Lau, James Y W; Poon, Carmen C Y

2017-01-01

Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. Although polypectomy at early stage reduces CRC incidence, 90% of the polyps are small and diminutive, where removal of them poses risks to patients that may outweigh the benefits. Correctly detecting and predicting polyp type during colonoscopy allows endoscopists to resect and discard the tissue without submitting it for histology, saving time, and costs. Nevertheless, human visual observation of early stage polyps varies. Therefore, this paper aims at developing a fully automatic algorithm to detect and classify hyperplastic and adenomatous colorectal polyps. Adenomatous polyps should be removed, whereas distal diminutive hyperplastic polyps are considered clinically insignificant and may be left in situ . A novel transfer learning application is proposed utilizing features learned from big nonmedical datasets with 1.4-2.5 million images using deep convolutional neural network. The endoscopic images we collected for experiment were taken under random lighting conditions, zooming and optical magnification, including 1104 endoscopic nonpolyp images taken under both white-light and narrowband imaging (NBI) endoscopy and 826 NBI endoscopic polyp images, of which 263 images were hyperplasia and 563 were adenoma as confirmed by histology. The proposed method identified polyp images from nonpolyp images in the beginning followed by predicting the polyp histology. When compared with visual inspection by endoscopists, the results of this study show that the proposed method has similar precision (87.3% versus 86.4%) but a higher recall rate (87.6% versus 77.0%) and a higher accuracy (85.9% versus 74.3%). In conclusion, automatic algorithms can assist endoscopists in identifying polyps that are adenomatous but have been incorrectly judged as hyperplasia and, therefore, enable timely resection of these polyps at an early stage before they develop into invasive cancer.

Present and future status of flexible spectral imaging color enhancement and blue laser imaging technology.

PubMed

Osawa, Hiroyuki; Yamamoto, Hironori

2014-01-01

The usefulness of flexible spectral imaging color enhancement (FICE) has been reported for evaluating the esophagus, stomach, and small and large intestine. Higher contrast is shown between cancer and the surrounding mucosa in the esophagus and stomach and may facilitate the detection of gastric cancers missed by white light imaging alone. The surface patterns of gastric mucosa are clearly visualized in non-malignant areas but are irregular and blurred in malignant areas, leading to clear demarcation. Capsule endoscopy with FICE detects angiodysplasia and erosions of the small intestine. The surface and vascular pattern with FICE is useful for the differential diagnosis of colorectal polyps. However, FICE remains somewhat poor at visualizing mucosal microvasculature on a tumor surface. Narrow-band imaging (NBI) is dark in observing whole gastric mucosa and poor at visualizing mucosal microstructure. Blue laser imaging (BLI) has the potential to resolve these limitations. Narrow-band laser light combined with white light shows irregular microvessels on both differentiated and undifferentiated gastric cancer similar to those using NBI. In addition, irregular surface patterns including minute white zones are clearly seen on the uneven surface of differentiated lesions, resulting in exclusion of undifferentiated lesions. Using both distant and close-up views, a high contrast between green intestinal metaplasia and brown gastric cancer may lead to early detection of gastric cancers and determination of a demarcation line. BLI produces high-contrast images in esophageal cancer with clear vision of intrapapillary capillary loops and also predicts the histopathological diagnosis and depth of invasion in colorectal neoplasms. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

Characterization of beam-driven instabilities and current redistribution in MST plasmas

NASA Astrophysics Data System (ADS)

Parke, E.

2015-11-01

A unique, high-rep-rate (>10 kHz) Thomson scattering diagnostic and a high-bandwidth FIR interferometer-polarimeter on MST have enabled characterization of beam-driven instabilities and magnetic equilibrium changes observed during high power (1 MW) neutral beam injection (NBI). While NBI leads to negligible net current drive, an increase in on-axis current density observed through Faraday rotation is offset by a reduction in mid-radius current. Identification of the phase flip in temperature fluctuations associated with tearing modes provides a sensitive measure of rational surface locations. This technique strongly constrains the safety factor for equilibrium reconstruction and provides a powerful new tool for measuring the equilibrium magnetic field. For example, the n = 6 temperature structure is observed to shift inward 1.1 +/- 0.6 cm, with an estimated reduction of q0 by 5%. This is consistent with a mid-radius reduction in current, and together the Faraday rotation and Thomson scattering measurements corroborate an inductive redistribution of current that compares well with TRANSP/MSTFit predictions. Interpreting tearing mode temperature structures in the RFP remains challenging; the effects of multiple, closely-spaced tearing modes on the mode phase measurement require further verification. In addition to equilibrium changes, previous work has shown that the large fast ion population drives instabilities at higher frequencies near the Alfvén continuum. Recent observations reveal a new instability at much lower frequency (~7 kHz) with strongly chirping behavior. It participates in extensive avalanches of the higher frequency energetic particle and Alfvénic modes to drive enhanced fast ion transport. Internal structures measured from Te and ne fluctuations, their dependence on the safety factor, as well as frequency scaling motivate speculation about mode identity. Work supported by U.S. DOE.

Potential link between caffeine consumption and pediatric depression: A case-control study.

PubMed

Benko, Cássia R; Farias, Antonio C; Farias, Lucilene G; Pereira, Erico F; Louzada, Fernando M; Cordeiro, Mara L

2011-08-25

Early-onset depressive disorders can have severe consequences both from developmental and functional aspects. The etiology of depressive disorders is complex and multi-factorial, with an intricate interaction among environmental factors and genetic predisposition. While data from studies on adults suggest that caffeine is fairly safe, effects of caffeine in children, who are in period of rapid brain development, are currently unknown. Furthermore, systematic research addressing the relationship between depressive symptoms in children and caffeine consumption is lacking.The present study examined the effects of caffeine consumption on depressed mood in children with depression and non-depressed participants. Children and adolescents (n = 51) already enrolled in an ongoing longitudinal study, aged 9-12 years, were assessed for depressive symptoms with the Children Depressive Inventory (CDI). Psychopathological symptoms were assessed with the Child Behavioral Checklist (CBCL) and eating habits were assessed with the Nutrition-Behavior Inventory (NBI) 1. The children were compared to control children without psychopathology attending public schools in a Southern Brazilian city. Participants with CDI scores ≥ 15 (mean = 19; S.D. = 4) also had high NBI scores (mean = 52; S.D. = 19, p < 0.001) suggestive of a relationship between depressive symptoms and environmental factors, in this case nutrition/behavior. Additional linear regression adjusted statistical analysis, considering the factors of consumption of sweets and caffeine individually, showed that caffeine, but not sweets, was associated with depressive symptoms. These findings indicate that depressed children consume more caffeinated drinks than non-depressed children. Nonetheless while a strong association between depressive symptoms and caffeine consumption among children was found, further research should investigate whether or not this association is due to a cause and effect relationship.

Potential link between caffeine consumption and pediatric depression: A case-control study

PubMed Central

2011-01-01

Background Early-onset depressive disorders can have severe consequences both from developmental and functional aspects. The etiology of depressive disorders is complex and multi-factorial, with an intricate interaction among environmental factors and genetic predisposition. While data from studies on adults suggest that caffeine is fairly safe, effects of caffeine in children, who are in period of rapid brain development, are currently unknown. Furthermore, systematic research addressing the relationship between depressive symptoms in children and caffeine consumption is lacking. The present study examined the effects of caffeine consumption on depressed mood in children with depression and non-depressed participants. Methods Children and adolescents (n = 51) already enrolled in an ongoing longitudinal study, aged 9-12 years, were assessed for depressive symptoms with the Children Depressive Inventory (CDI). Psychopathological symptoms were assessed with the Child Behavioral Checklist (CBCL) and eating habits were assessed with the Nutrition-Behavior Inventory (NBI) [1]. The children were compared to control children without psychopathology attending public schools in a Southern Brazilian city. Results Participants with CDI scores ≥ 15 (mean = 19; S.D. = 4) also had high NBI scores (mean = 52; S.D. = 19, p < 0.001) suggestive of a relationship between depressive symptoms and environmental factors, in this case nutrition/behavior. Additional linear regression adjusted statistical analysis, considering the factors of consumption of sweets and caffeine individually, showed that caffeine, but not sweets, was associated with depressive symptoms. Conclusions These findings indicate that depressed children consume more caffeinated drinks than non-depressed children. Nonetheless while a strong association between depressive symptoms and caffeine consumption among children was found, further research should investigate whether or not this association is due to a cause and effect relationship. PMID:21867528

Design of the optical backscatter diagnostic for laser plasma interaction measurements on NIF

NASA Astrophysics Data System (ADS)

Moody, J. D.; Datte, P.; Ng, E.; Maitland, K.; Hsing, W.; MacGowan, B. J.; Froula, D. H.; Neumayer, P.; Sutter, L.; Meezan, N.; Glenzer, S. H.; Kirkwood, R. K.; Divol, L.; Andrews, S.; Jackson, J.; MacKinnon, A.; Jovanovic, I.; Beeler, R.; Bertolini, L.; Landon, M.; Alvarez, S.; Lee, T.; Watts, P.

2007-11-01

We describe the design of the backscatter diagnostic for NIF laser-plasma interaction (LPI) studies. It will initially be used to validate the 280 eV point design hohlraum and select phase plates for the ignition experiments. Backscatter measurements are planned for two separate groups of 4 beams (a quad). One quad is 30^o from the hohlraum axis and the other at 50^o. The backscatter measurement utilizes 2 instruments for each beam quad. The full aperture backscatter system (FABS) measures light backscattered into the final focus lens of each beam in the quad. The near backscatter imager (NBI) measures light backscattered outside of the beam quad. Both instruments must work in conjunction to provide spectrally and temporally resolved backscatter power. We describe the design of the diagnostic and its capabilities as well as plans for calibrating it and analyzing the resulting data. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

The R&D progress of 4 MW EAST-NBI high current ion source.

PubMed

Xie, Yahong; Hu, Chundong; Liu, Sheng; Xu, Yongjian; Liang, Lizhen; Xie, Yuanlai; Sheng, Peng; Jiang, Caichao; Liu, Zhimin

2014-02-01

A high current ion source, which consists of the multi-cusp bucket plasma generator and tetrode accelerator with multi-slot apertures, is developed and tested for the Experimental Advanced Superconducting Tokamak neutral beam injector. Three ion sources are tested on the test bed with arc power of 80 kW, beam voltage of 80 keV, and beam power of 4 MW. The arc regulation technology with Langmuir probes is employed for the long pulse operation of ion source, and the long pulse beam of 50 keV @ 15.5 A @ 100 s and 80 keV @ 52A @ 1s are extracted, respectively.

Diurnal carbon system variability and hydrodynamics on coral reefs of Palau and Palmyra Atoll

NASA Astrophysics Data System (ADS)

Teneva, L. T.; Dunbar, R. B.; Fleischfresser, J. D.; Koweek, D.; Koseff, J. R.; Mucciarone, D. A.

2012-12-01

The rates of coral reef response to ocean pH changes and the implications for ecosystem resilience remain largely unknown. Our ability to predict the impacts of ocean acidification hinges on an improved understanding of temporal and spatial measurements of coral reef carbon budgets. Here we report on the first 5-minute resolution multi-day carbon system measurements from Palau and Palmyra Atoll collected in April 2011 and September 2011, respectively. Our experimental approach uses a custom-made automated continuous flow system capable of resolving pH, temperature, and salinity on a 10-second timescale, and Dissolved Inorganic Carbon (DIC) on a 5-minute timescale. At Palmyra Atoll, a lagoonal site of North Barren Island (NBI) was characterized by high amplitude in diel biogeochemical variability: pH 7.93-8.2 (mean: 8.06± 0.06), pCO2 211.4-535.2 (μatm) (mean: 364.8 ± 72.2) nTA 2141.5-2297.5 (μmol/kg) (mean: 2216.7 ± 35.2), nDIC 1626.5 - 2069.9(μmol/kg) (mean: 1908.4 ± 86.3), ΩARAG 3.04-5 (mean: 3.91 ± 0.43), and dissolved oxygen 100.6-285.0 (mL/L) (mean: 178.4 ± 47.3). Variability observed at well-mixed back reef site at Palmyra Atoll, named Penguin Spit, was smaller compared with NBI: pH 8.06-8.18 (mean: 8.12 ± 0.03), pCO2 263.6-380.4 (μatm) (mean: 319.9 ± 29.0), nTA 2232.0-2307.8 (μmol/kg) (mean: 2278.9 ± 15.2), nDIC 1848.2-2052.0 (μmol/kg) (mean: 1972.8 ± 35.4), and ΩARAG 4.03-4.99 (mean: 4.5 ± 0.24), and dissolved oxygen 155.4-214.2 (mL/L) (mean: 181.4 ± 15.5). At Palau we observe the following ranges in a backreef environment: pH 8.07-8.24 (mean: 8.15 ± 0.03), pCO2 330.6-519.9 (μatm) (mean: 420.9 ± 35.2), nTA 2171.1-2357.8 (μmol/kg) (mean: 2234.1 ± 25.2), nDIC 1834.4-2120.6 μmol/kg (mean: 1954.3±35.8), ΩARAG 2.84-3.98 (mean: 3.36 ±0.2). Local hydrodynamics can attenuate or enhance coral reef metabolism signals within the water column to different extent at different reef sites. Such field studies contribute to a broader database of reefal carbon budgets and highlight the need for future ocean acidification impact projections to account for inter- and intra-island spatial heterogeneity in pH conditions and commensurate net community calcification and net community production rates.

U.S. Geological Survey's ShakeCast: A cloud-based future

USGS Publications Warehouse

Wald, David J.; Lin, Kuo-Wan; Turner, Loren; Bekiri, Nebi

2014-01-01

When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap portrays the extent of potentially damaging shaking. In turn, the ShakeCast system, a freely-available, post-earthquake situational awareness application, automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users’ facilities, sends notifications of potential damage to responsible parties, and generates facility damage assessment maps and other web-based products for emergency managers and responders. ShakeCast is particularly suitable for earthquake planning and response purposes by Departments of Transportation (DOTs), critical facility and lifeline utilities, large businesses, engineering and financial services, and loss and risk modelers. Recent important developments to the ShakeCast system and its user base are described. The newly-released Version 3 of the ShakeCast system encompasses advancements in seismology, earthquake engineering, and information technology applicable to the legacy ShakeCast installation (Version 2). In particular, this upgrade includes a full statistical fragility analysis framework for general assessment of structures as part of the near real-time system, direct access to additional earthquake-specific USGS products besides ShakeMap (PAGER, DYFI?, tectonic summary, etc.), significant improvements in the graphical user interface, including a console view for operations centers, and custom, user-defined hazard and loss modules. The release also introduces a new adaption option to port ShakeCast to the "cloud". Employing Amazon Web Services (AWS), users now have a low-cost alternative to local hosting, by fully offloading hardware, software, and communication obligations to the cloud. Other advantages of the "ShakeCast Cloud" strategy include (1) Reliability and robustness of offsite operations, (2) Scalability naturally accommodated, (3), Serviceability, problems reduced due to software and hardware uniformity, (4) Testability, freely available for new users, (5) Remotely supported, allowing expert-facilitated maintenance, (6) Adoptability, simplified with disk images, and (7) Security, built in at the very high level associated with AWS. The ShakeCast user base continues to expand and broaden. For example, Caltrans, the prototypical ShakeCast user and development supporter, has been providing guidance to other DOTs on the use of the National Bridge Inventory (NBI) database to implement fully-functional ShakeCast systems in their states. A long-term goal underway is to further "connect the DOTs" via a Transportation Pooled Fund (TPF) with participating state DOTs. We also review some of the many other users and uses of ShakeCast. Lastly, on the hazard input front, we detail related ShakeMap improvements and ongoing advancements in estimating the likelihood of shaking-induced secondary hazards at structures, facilities, bridges, and along roadways due to landslides and liquefaction, and implemented within the ShakeCast framework.

[Endoscopical features of precancer changes of the stomach in patients with chronic gastric erosions and biliary tract disease].

PubMed

Solovĭova, H A

2012-01-01

Frequency of the precancer changes of the stomach, diagnosed by using zoom-endoscopy, NBI, chromoscopy, in the three groups of patients: with gastric erosions and biliary tract diseases, with gastric erosions and duodenal ulcer disease, with gastric erosions and chronic gastritis is compared in the article. It is shown, that patients with gastric erosions and biliary tract diseases are characterized by bigger spreading of precancer changes: atrophy, intestinal metaplasia with predominant smalluently intestine in gastric body, intestine metaplasia in antral part of the stomach is revealed more freq in these category of patients. A strong correlation between endoscopical and morphological methods of investigation was demonstrated.

Comparison of TIMS and MC-ICP-MS Analyses of Pb Isotopic Compositions on Prehistoric Mauna Loa Basalts: Implications for Plume Source Components

NASA Astrophysics Data System (ADS)

De Jong, J.; Weis, D.; Maerschalk, C.; Rhodes, J. M.

2001-12-01

Recent isotopic studies on Hawaiian lavas have shown the necessity of constraining fractionation for Pb isotopes. This isotopic system presents systematic variations reflecting the presence of different plume components in the source of Hawaiian basalts. We have analyzed a series of 23 tholeiitic Mauna Loa basalts ranging in age from 36,780 to 140 y for their Pb isotopic compositions by TIMS (Micromass Sector 54) and MC-ICP-MS (Nu Plasma) to directly compare results from the same, carefully leached, samples. These analyses indicate an internal precision better than 120 ppm for the MC-ICP-MS Pb ratios, while for the TIMS ratios, it is in the per mil range. This results in a more coherent dataset for the MC-ICP-MS analyses, with the range of 207Pb/204Pb variations decreasing by a factor of 3 and of 208Pb/204Pb ratios by a factor of 1.5. The co-variations between the Pb isotopic data and other geochemical parameters for the Hawaiian lavas are now much stronger and better defined. There are clearly two groups amongst the prehistoric Mauna Loa basalts: one group with higher 87Sr/86Sr (>0.7038) and low 206Pb/204Pb (<18.15) that covers the entire range of Nb/Y (0.31 to 0.51) observed in this volcano, and the other group with low 87Sr/86Sr (<0.7038) and higher 206Pb/204Pb with Nb/Y<0.4. The second group is only present in basalts younger than 3,000 y or older than 24,000 y. The high 87Sr/86Sr group was not sampled in the HSDP I drill core, which covers an age range of 100,000 y. This either reflects a sampling bias, as the upper flow units (<10,000 y) were not sampled for geochemistry, or variations in magma supply. Altogether, Mauna Loa lava flows that are younger than 20,000 y show much more isotopic variation than older flows and there is a nearly continuous transition away from the Kilauea component. This may indicate that the transition between the Mauna Loa and Mauna Kea trends is not as sharp as previously documented. This study shows the importance of reducing the error associated with mass fractionation by measuring Pb isotopes by MC-ICP-MS to constrain plume components in the mantle source of oceanic basalts.

Three-dimensional modeling of a negative ion source with a magnetic filter: impact of biasing the plasma electrode on the plasma asymmetry

NASA Astrophysics Data System (ADS)

Fubiani, G.; Boeuf, J. P.

2015-10-01

The effect on the plasma characteristics of biasing positively the plasma electrode (PE) in negative ion sources with a magnetic filter is analysed using a 3D particle-in-cell model with Monte-Carlo collisions (PIC-MCC). We specialize to the one driver (i.e. one inductively coupled radio-frequency discharge) BATMAN negative ion source and the 4-drivers (large volume) ELISE device. Both are ITER prototype high power tandem-type negative ion sources developed for the neutral beam injector (NBI) system. The plasma is generated in the driver and diffuses inside the second chamber which is magnetized. Asymmetric plasma profiles originate from the formation of an electric field transverse to the electron current flowing through the magnetic filter (Hall effect). The model shows that the importance of the asymmetry increases with the PE bias potential, i.e. with the electron flow from the driver to the extraction region and depends on the shape of the magnetic filter field. We find that although the plasma density and potential profiles may be more or less asymmetric depending on the filter field configuration, the electron current to the plasma grid is always strongly asymmetric.

Control of ITBs in Magnetically Confined Burning Plasmas

NASA Astrophysics Data System (ADS)

Panta, S. R.; Newman, D. E.; Terry, P. W.; Sanchez, R.

2017-10-01

In the magnetically confined burning plasma devices (in this case Tokamaks), internal transport barriers (ITBs) are those regimes in which the turbulence is suppressed by the E X B velocity shear, reducing the turbulent transport. This often occurs at a critical gradient in the profiles. The change in the transport then modifies the density and temperature profiles feeding back on the system. These transport barriers have to be controlled both to form them for improved confinement and remove them to both prevent global instabilities and to remove the ash and unnecessary impurities in the device. In this work we focus on pellet injection and modulated RF heating as a way to trigger and control the ITBs. These have an immediate consequence on density and temperature and hence pressure profiles acting as a control knob. For example, depending upon pellet size and its radial position of injection, it either helps to form or strengthen the barrier or to get rid of ITBs in the different transport channels of the burning plasmas. This transport model is then used to investigate the control and dynamics of the transport barriers in burning plasmas using pellets and RF addition to the NBI power and alpha power.

Dust Studies in DIII-D and TEXTOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudakov, D L; Litnovsky, A; West, W P

2009-02-17

Studies of naturally occurring and artificially introduced carbon dust are conducted in DIII-D and TEXTOR. In DIII-D, dust does not present operational concerns except immediately after entry vents. Submicron sized dust is routinely observed using Mie scattering from a Nd:Yag laser. The source is strongly correlated with the presence of Type I edge localized modes (ELMs). Larger size (0.005-1 mm diameter) dust is observed by optical imaging, showing elevated dust levels after entry vents. Inverse dependence of the dust velocity on the inferred dust size is found from the imaging data. Direct heating of the dust particles by the neutralmore » beam injection (NBI) and acceleration of dust particles by the plasma flows are observed. Energetic plasma disruptions produce significant amounts of dust. Large flakes or debris falling into the plasma may result in a disruption. Migration of pre-characterized carbon dust is studied in DIII-D and TEXTOR by introducing micron-size dust in plasma discharges. In DIII-D, a sample holder filled with {approx}30 mg of dust is introduced in the lower divertor and exposed to high-power ELMing H-mode discharges with strike points swept across the divertor floor. After a brief exposure ({approx}0.1 s) at the outer strike point, part of the dust is injected into the plasma, raising the core carbon density by a factor of 2-3 and resulting in a twofold increase of the radiated power. In TEXTOR, instrumented dust holders with 1-45 mg of dust are exposed in the scrape-off layer 0-2 cm radially outside of the last closed flux surface in discharges heated with neutral beam injection (NBI) power of 1.4 MW. At the given configuration of the launch, the dust did not penetrate the core plasma and only moderately perturbed the edge plasma, as evidenced by an increase of the edge carbon content.« less

Modeling of fast neutral-beam-generated ion effects on MHD-spectroscopic observations of resistive wall mode stability in DIII-D plasmas [Modeling of fast neutral-beam-generated ion effects on MHD spectroscopic observations of RWM stability in DIII-D plasmas

DOE PAGES

Turco, Francesca; Turnbull, Alan D.; Hanson, Jeremy M.; ...

2015-02-03

Experiments conducted at DIII-D investigate the role of drift kinetic damping and fast neutral beam injection (NBI)-ions in the approach to the no-wall β N limit. Modelling results show that the drift kinetic effects are significant and necessary to reproduce the measured plasma response at the ideal no-wall limit. Fast neutral-beam ions and rotation play important roles and are crucial to quantitatively match the experiment. In this paper, we report on the model validation of a series of plasmas with increasing β N, where the plasma stability is probed by active magnetohydrodynamic (MHD) spectroscopy. The response of the plasma tomore » an externally applied field is used to probe the stable side of the resistive wall mode and obtain an indication of the proximity of the equilibrium to an instability limit. We describe the comparison between the measured plasma response and that calculated by means of the drift kinetic MARS-K code, which includes the toroidal rotation, the electron and ion drift-kinetic resonances, and the presence of fast particles for the modelled plasmas. The inclusion of kinetic effects allows the code to reproduce the experimental results within ~13% for both the amplitude and phase of the plasma response, which is a significant improvement with respect to the undamped MHD-only model. The presence of fast NBI-generated ions is necessary to obtain the low response at the highest β N levels (~90% of the ideal no-wall limit). Finally, the toroidal rotation has an impact on the results, and a sensitivity study shows that a large variation in the predicted response is caused by the details of the rotation profiles at high β N.« less

Dust studies in DIII-D and TEXTOR

NASA Astrophysics Data System (ADS)

Rudakov, D. L.; Litnovsky, A.; West, W. P.; Yu, J. H.; Boedo, J. A.; Bray, B. D.; Brezinsek, S.; Brooks, N. H.; Fenstermacher, M. E.; Groth, M.; Hollmann, E. M.; Huber, A.; Hyatt, A. W.; Krasheninnikov, S. I.; Lasnier, C. J.; McLean, A. G.; Moyer, R. A.; Pigarov, A. Yu.; Philipps, V.; Pospieszczyk, A.; Smirnov, R. D.; Sharpe, J. P.; Solomon, W. M.; Watkins, J. G.; Wong, C. P. C.

2009-08-01

Studies of naturally occurring and artificially introduced carbon dust are conducted in DIII-D and TEXTOR. In DIII-D, dust does not present operational concerns except immediately after entry vents. Submicrometre sized dust is routinely observed using Mie scattering from a Nd : Yag laser. The source is strongly correlated with the presence of type I edge localized modes (ELMs). Larger size (0.005-1 mm diameter) dust is observed by optical imaging, showing elevated dust levels after entry vents. Inverse dependence of the dust velocity on the inferred dust size is found from the imaging data. Heating of the dust particles by the neutral beam injection (NBI) and acceleration of dust particles by the plasma flows are observed. Energetic plasma disruptions produce significant amounts of dust; on the other hand, large flakes or debris falling into the plasma may induce a disruption. Migration of pre-characterized carbon dust is studied in DIII-D and TEXTOR by introducing micrometre-size particles into plasma discharges. In DIII-D, a sample holder filled with 30-40 mg of dust is inserted in the lower divertor and exposed, via sweeping of the strike points, to the diverted plasma flux of high-power ELMing H-mode discharges. After a brief dwell (~0.1 s) of the outer strike point on the sample holder, part of the dust penetrates into the core plasma, raising the core carbon density by a factor of 2-3 and resulting in a twofold increase in the radiated power. In TEXTOR, instrumented dust holders with 1-45 mg of dust are exposed in the scrape-off-layer 0-2 cm radially outside of the last closed flux surface in discharges heated with 1.4 MW of NBI. Launched in this configuration, the dust perturbed the edge plasma, as evidenced by a moderate increase in the edge carbon content, but did not penetrate into the core plasma.

The major results from W7-AS stellarator

NASA Astrophysics Data System (ADS)

Wagner, Friedrich

2002-11-01

W7-AS has terminated operation this summer. In the last phase, W7-AS was equipped with an island divertor using the natural edge islands of the low-shear, n=5 design. NBI heating has been done with co-injection (3 MW), ECRH was successfully extended to high density with the OXB scheme, and ICRH was applied in all standard modes but also in beach wave heating. The island divertor allowed high β and provided excellent exhaust conditions thanks to the accessibility to high densities (ne <= 4 × 10^20 m-3). 3D edge modelling with the EMC3-EIRENE code predicted and explained the absence of the high-recycling regime and the low-density high-temperature momentum losses associated with the prominent role of the cross-field transport. The confinement of W7-AS is determined by two concept dependent features low shear and 3D geometry: τE depends strongly on low-order rationals; in the plasma core the neo-classical bifurcation between ion and electron roots is observed. A distinct difference to tokamaks is the lack of Te - profile resilience. The H-mode operational range is governed by poloidal flow damping. At high density, a further bifurcation appears into a regime characterised by good energy and low impurity confinement (HDH). Because of its appealing features, this regime will be described in detail. The most visible MHD are beam driven global Alfven modes and ELMs. The operational limits are set by NBI power: The balance of heating and edge radiation determines the density limit; the maximal β is limited to 3.1%. The operation at high densities and high β is quiescent and quasi-steady state. The intrinsic stellarator features - steady state and no disruptions - remain close to operational limits. The results of W7-AS confirm the design criteria of W7-X and contribute to establish the stellarator line as independent route to a reactor.

Confinement & Stability in MAST

NASA Astrophysics Data System (ADS)

Akers, Rob

2001-10-01

Transition to H-mode has been achieved in the MAST spherical tokamak (ST) for both ohmically and neutral beam heated plasmas (P_NBI ~ 0.5-1.5MW), resulting in double-null diverted discharges containing both regular and irregular edge localised modes (ELMs). The observed L-H power threshold is ~10 times higher than predicted by established empirical scalings. L-H transition in MAST is accompanied by a sharp increase in edge density gradient, the efficient conversion of internal electron Bernstein waves into free space waves, the onset and saturation of edge poloidal rotation and a marked decrease in turbulence. During ELM free periods, a reduction in outboard power deposition width is observed using a Langmuir probe array. A novel divertor structure has been installed to counter the resulting increase in target heat-flux by applying a toroidally varying potential to the divertor plasma, theory suggesting that convective broadening of the scrape off layer will take place. Global confinement in H-mode is found to routinely exceed the international IPB(y,2) scaling, even for discharges approaching the Greenwald density. In an attempt to further extend the density range (densities in excess of Greenwald having been achieved for plasma currents up to 0.8MA) a multi-pellet injector has been installed at the low-field-side. In addition, high field side fuelling can be supplied via a gas-feed located at the centre-column mid-plane, this technique having been found to significantly enhance H-mode accessibility and quality. A range of stability issues will be discussed, including vertical displacement events, the rich variety of high frequency MHD seen in MAST and the physics of the Neoclassical Tearing Mode. This work was funded by the UK Department of Trade and Industry and by EURATOM. The NBI equipment is on loan from ORNL and the pellet injector was provided by FOM.

Endocytoscopic findings of lymphomas of the stomach.

PubMed

Isomoto, Hajime; Matsushima, Kayoko; Hayashi, Tomayoshi; Imaizumi, Yoshitaka; Shiota, Junya; Ishii, Hiroyuki; Minami, Hitomi; Ohnita, Ken; Takeshima, Fuminao; Shikuwa, Saburo; Miyazaki, Yasushi; Nakao, Kazuhiko

2013-12-26

The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy. Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma. On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression. On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy.

Feasibility study of ECRH in NSTX-U startup plasma

NASA Astrophysics Data System (ADS)

Lopez, N. A.; Poli, F.; Taylor, G.; Harvey, R.; Petrov, Yu.

2016-10-01

A key mission goal of the National Spherical Torus eXperiment Upgrade (NSTX-U) is the demonstration of fully non-inductive startup and operation. In part to accomplish this, a 1MW, 28 GHz ECRH system is presently being developed for implementation on NSTX-U in 2018. Like most spherical tokamaks, NSTX-U operates in the overdense regime (fpe>fce) , which limits traditional ECRH to the early startup phase. An extensive modelling effort of the propagation and absorption of EC waves in the evolving plasma is thus required to define the most effective window of operation, and to optimize the launcher geometry for maximal heating and for current drive during this window. In fact, the ECRH system will play an important role in preparing a target plasma for subsequent injection of IC waves and NBI. Here we assess the feasibility of O1-mode ECRH in NSTX-U startup plasma at full field of 1T through time-dependent simulations performed with the transport solver TRANSP. Linear ray-tracing calculations conducted by GENRAY are coupled into the TRANSP framework, allowing the plasma equilibrium and the temperature profiles to evolve self-consistently in response to the injected microwave power. Furthermore, we investigate additional possibilities of heating and current drive made available through coupling the injected O-mode power to the electrostatic EBW via the slow X-mode as an intermediary.

Indiplon in the management of insomnia

PubMed Central

Lemon, Michael D; Strain, Joe D; Hegg, Annie M; Farver, Debra K

2009-01-01

Indiplon is a novel pyrazolopyrimidine, nonbenzodiazepine γ-aminobutyric acid (GABA) agonist studied for the treatment of insomnia. This article reviews the chemistry, pharmacology, clinical pharmacokinetics, drug interactions, clinical trials, safety, tolerability, contraindications, use in special populations, and dosing of indiplon. OVID, International Pharmaceutical Abstracts (IPA), and PubMed databases were searched (1966 to February 2009) for the keywords indiplon, NBI-34060, and insomnia. References of key articles were also reviewed to identify additional publications. Only English language articles were selected for review. Indiplon has been shown to have high affinity and selectivity for the GABAα1 receptor subunit associated with sedation. In clinical studies, indiplon has demonstrated efficacy in improving latency to sleep onset, latency to persistent sleep, total sleep time, wake time after sleep onset, number of awakenings after sleep onset, and overall sleep quality when compared to placebo. Indiplon has a favorable safety profile with limited rebound insomnia and no tolerance. Neurocrine Biosciences, Incorporated received an Approvable Letter from the United States Food and Drug Administration in December 2007 for the indiplon IR 5 mg and 10 mg capsules based on meeting three additional requirements. At the time of this writing, indiplon remains unapproved. PMID:19920929

Indiplon in the management of insomnia.

PubMed

Lemon, Michael D; Strain, Joe D; Hegg, Annie M; Farver, Debra K

2009-09-21

Indiplon is a novel pyrazolopyrimidine, nonbenzodiazepine gamma-aminobutyric acid (GABA) agonist studied for the treatment of insomnia. This article reviews the chemistry, pharmacology, clinical pharmacokinetics, drug interactions, clinical trials, safety, tolerability, contraindications, use in special populations, and dosing of indiplon. OVID, International Pharmaceutical Abstracts (IPA), and PubMed databases were searched (1966 to February 2009) for the keywords indiplon, NBI-34060, and insomnia. References of key articles were also reviewed to identify additional publications. Only English language articles were selected for review. Indiplon has been shown to have high affinity and selectivity for the GABAalpha(1) receptor subunit associated with sedation. In clinical studies, indiplon has demonstrated efficacy in improving latency to sleep onset, latency to persistent sleep, total sleep time, wake time after sleep onset, number of awakenings after sleep onset, and overall sleep quality when compared to placebo. Indiplon has a favorable safety profile with limited rebound insomnia and no tolerance. Neurocrine Biosciences, Incorporated received an Approvable Letter from the United States Food and Drug Administration in December 2007 for the indiplon IR 5 mg and 10 mg capsules based on meeting three additional requirements. At the time of this writing, indiplon remains unapproved.

A Finite-Orbit-Width Fokker-Planck solver for modeling of RF Current Drive in ITER

NASA Astrophysics Data System (ADS)

Petrov, Yu. V.; Harvey, R. W.

2017-10-01

The bounce-average (BA) finite-difference Fokker-Planck (FP) code CQL3D now includes the essential physics to describe the RF heating of Finite-Orbit-Width (FOW) ions in tokamaks. The FP equation is reformulated in terms of constants-of-motion coordinates, which we select to be particle speed, pitch angle, and major radius on the equatorial plane thus obtaining the distribution function directly at this location. A recent development is the capability to obtain solution simultaneously for FOW ions and Zero-Orbit-Width (ZOW) electrons. As a practical application, the code is used for simulation of alpha-particle heating by high-harmonic waves in ITER scenarios. Coupling of high harmonic or helicon fast waves power to electrons is a promising current drive (CD) scenario for high beta plasmas. However, the efficiency of current drive can be diminished by parasitic channeling of RF power into fast ions such as alphas or NBI-produced deuterons, through finite Larmor-radius effects. Based on simulations, we formulate conditions where the fast ions absorb less than 10% of RF power. Supported by USDOE Grants ER54649, ER54744, and SC0006614.

Detection of malignant lesions in vivo in the upper gastrointestinal tract using image-guided Raman endoscopy

NASA Astrophysics Data System (ADS)

Bergholt, Mads Sylvest; Zheng, Wei; Lin, Kan; Ho, Khek Yu; Yeoh, Khay Guan; Teh, Ming; So, Jimmy Bok Yan; Huang, Zhiwei

2012-01-01

Raman spectroscopy is a vibrational analytic technique sensitive to the changes in biomolecular composition and conformations occurring in tissue. With our most recent development of near-infrared (NIR) Raman endoscopy integrated with diagnostic algorithms, in vivo real-time Raman diagnostics has been realized under multimodal wide-field imaging (i.e., white- light reflectance (WLR), narrow-band imaging (NBI), autofluorescence imaging (AFI)) modalities. A selection of 177 patients who previously underwent Raman endoscopy (n=2510 spectra) was used to render two robust models based on partial least squares - discriminant analysis (PLS-DA) for esophageal and gastric cancer diagnosis. The Raman endoscopy technique was validated prospectively on 4 new gastric and esophageal patients for in vivo tissue diagnosis. The Raman endoscopic technique could identify esophageal cancer in vivo with a sensitivity of 88.9% (8/9) and specificity of 100.0% (11/11) and gastric cancers with a sensitivity of 77.8% (14/18) and specificity of 100.0% (13/13). This study realizes for the first time the image-guided Raman endoscopy for real-time in vivo diagnosis of malignancies in the esophagus and gastric at the biomolecular level.

A GDT-based fusion neutron source for academic and industrial applications

NASA Astrophysics Data System (ADS)

Anderson, J. K.; Forest, C. B.; Mirnov, V. V.; Peterson, E. E.; Waleffe, R.; Wallace, J.; Harvey, R. W.

2017-10-01

The design of a fusion neutron source based on the gas dynamic trap (GDT) configuration is underway. The motivation is both the ends and the means. There are immediate applications for neutrons including medical isotope production and actinide burners. Taking the next step in the magnetic mirror path will leverage advances in high-temperature superconducting magnets and additive manufacturing in confining a fusion plasma, and both the technological and physics bases exist. Recent breakthrough results at the GDT facility in Russia demonstrate stable confinement of a beta 60% mirror plasma at high Te ( 1 keV). These scale readily to a fusion neutron source with an increase in magnetic field, mirror ratio, and ion energy. Studies of a next-step compact device focus on calculations of MHD equilibrium and stability, and Fokker-Planck modeling to optimize the heating scenario. The conceptualized device uses off-the-shelf MRI magnets for a 1 T central field, REBCO superconducting mirror coils (which can currently produce fields in excess of 30T), and existing 75 keV NBI and 140 GHz ECRH. High harmonic fast wave injection is damped on beam ions, dramatically increasing the fusion reactivity for an incremental bump in input power. MHD stability is achieved with the vortex confinement scheme, where a biasing profile imposes optimal ExB rotation of the plasma. Liquid metal divertors are being considered in the end cells. Work supported by the Wisconsin Alumni Research Foundation.

National Spherical Torus Experiment (NSTX) and Planned Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Yueng Kay Martin; Ono, M.; Kaye, S.

1998-01-01

The U.S. fusion energy sciences program began in 1996 to increase emphasis on confinement concept innovation. The NSTX is being built at PPPL as a national fusion science research facility in response to this emphasis. NSTX is to test fusion science principles of the Spherical Torus (ST) plasmas, which include: (1) High plasma pressure in low magnetic field for high fusion power density, (2) Good energy confinement is a small-size plasma, (3) Nearly fully self-driven (bootstrap) plasma current, (4) Dispersed heat and particle fluxes, and (5) Plasma startup without complicated in board solenoid magnet. These properties of the ST plasma,more » if verified, would lead to possible future fusion devices of high fusion performance, small size, feasible power handling, and improved economy. The design of NSTX is depicted in a figure. The vessel will be covered fully with graphite tiles and can be baked to 350 C. Other wall condition techniques are also planned. The NSTX facilty extensively utilizes the equipment at PPPL and other reasearch institutions in collaboration. These include 6-MW High Harmonic Fast Wave (HHFW) power at {approx}30 MHz for 5 s, which will be the primary heating and current drive system following the first plasma planned for April 1999, and small ECH systems to assist breakdown for initiation. A plethora of diagnostics from TFTR and collaborators are planned. A NBI system from TFTR capable of delivering 5 MW at 80 keV for 5 s, and more powerful ECH systems are also planned for installation in 2000. The baseline plan for diagnostics systems are laid out in a figure and include: (1) Rogowski coils to measure total plasma and halo curents.« less

Extended capability of the integrated transport analysis suite, TASK3D-a, for LHD experiment

NASA Astrophysics Data System (ADS)

Yokoyama, M.; Seki, R.; Suzuki, C.; Sato, M.; Emoto, M.; Murakami, S.; Osakabe, M.; Tsujimura, T. Ii.; Yoshimura, Y.; Ido, T.; Ogawa, K.; Satake, S.; Suzuki, Y.; Goto, T.; Ida, K.; Pablant, N.; Gates, D.; Warmer, F.; Vincenzi, P.; Simulation Reactor Research Project, Numerical; LHD Experiment Group

2017-12-01

The integrated transport analysis suite, TASK3D-a (Analysis), has been developed to be capable for routine whole-discharge analyses of plasmas confined in three-dimensional (3D) magnetic configurations such as the LHD. The routine dynamic energy balance analysis for NBI-heated plasmas was made possible in the first version released in September 2012. The suite has been further extended through implementing additional modules for neoclassical transport and ECH deposition for 3D configurations. A module has also been added for creating systematic data for the International Stellarator-Heliotron Confinement and Profile Database. Improvement of neutral beam injection modules for multiple-ion species plasmas and loose coupling with a large-simulation code are also highlights of recent developments.

Preliminary measurements of neutrons from the D-D reaction in the COMPASS tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dankowski, J., E-mail: jan.dankowski@ifj.edu.pl; Kurowski, A.; Twarog, D.

Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during experiment. He-3 detectors and bubble detectors as a support. The measurements are an introduction for neutron diagnostic on tokamak COMPASS and monitoring neutrons during discharges with Neutral Beam Injection (NBI). The He-3 counters and bubble detectors were located in two positions near tokamak vacuum chamber at a distance less than 40 cm to the centre of plasma. The neutrons flux was observed in ohmic discharges. However, analysis of our resultsmore » does not indicate any clear source of neutrons production during ohmic discharges.« less

Inter-ELM evolution of the pedestal structures in type-I ELMy H-mode plasmas with LHW and NBI heating on EAST

NASA Astrophysics Data System (ADS)

Han, X.; Zang, Q.; Xiao, S.; Wang, T.; Hu, A.; Tian, B.; Li, D.; Zhou, H.; Zhao, J.; Hsieh, C.; Li, M.; Yan, N.; Gong, X.; Hu, L.; Xu, G.; Gao, X.; the EAST Team

2017-04-01

The evolution characteristics of type-I ELMy high-confinement mode pedestal are examined in EAST based on the recently developed Thomson scattering system. The influence of the plasma current on pedestal evolvement has been confirmed experimentally. In the higher I p case (500 kA) the pedestal height shows an increase trend until the onset of next ELM and in the lower I p cases (300 and 400 kA), however, this buildup saturates at the first ˜30% of the ELM cycle. In contrast, the width increases only during the first ˜70% of the ELM cycle and then keeps almost stable in three I p cases, but resulting in different widening size of ˜1.5, 1 and 0.5 cm for 300, 400 and 500 kA respectively. Experimental results show that the pedestal pressure width has good correlation with poloidal beta as {{{Δ }}}{{p}{{e}},\\psi }=0.16\\sqrt{{{β }}{{p}{{o}}{{l}}}}, where the fitting coefficient 0.16 is not changed with different plasma currents but a little larger than that of other machines. For each current level, the pedestal density increases while the pedestal temperature decreases. But with increasing {I}{{p}} platforms, the pedestal height prior to the ELM onset shows a near quadratic (within error bars) increase. Experimental measurements demonstrate that the decrease of {{Δ }}{W}{{E}{{L}}{{M}}} with increasing {ν }{{p}{{e}}{{d}}}* comes mostly from the reduction of the plasma temperature drop, while the pedestal density height keeps relatively stable. Additional injection of LHW has been proved to modify the pedestal structure which should be responsible for the remaining scatter of the experimental data.

Radiation Safety System for SPIDER Neutral Beam Accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandri, S.; Poggi, C.; Coniglio, A.

2011-12-13

SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma only) and MITICA (Megavolt ITER Injector Concept Advanced) are the ITER neutral beam injector (NBI) testing facilities of the PRIMA (Padova Research Injector Megavolt Accelerated) Center. Both injectors accelerate negative deuterium ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER with a maximum beam current of 40 A for both experiments. The SPIDER facility is classified in Italy as a particle accelerator. At present, the design of the radiation safety system for the facility has been completed and the relevant reports havemore » been presented to the Italian regulatory authorities. Before SPIDER can operate, approval must be obtained from the Italian Regulatory Authority Board (IRAB) following a detailed licensing process. In the present work, the main project information and criteria for the SPIDER injector source are reported together with the analysis of hypothetical accidental situations and safety issues considerations. Neutron and photon nuclear analysis is presented, along with special shielding solutions designed to meet Italian regulatory dose limits. The contribution of activated corrosion products (ACP) to external exposure of workers has also been assessed. Nuclear analysis indicates that the photon contribution to worker external exposure is negligible, and the neutron dose can be considered by far the main radiation protection issue. Our results confirm that the injector has no important radiological impact on the population living around the facility.« less

A first characterization of the NIO1 particle beam by means of a diagnostic calorimeter

NASA Astrophysics Data System (ADS)

Pimazzoni, A.; Cavenago, M.; Cervaro, V.; Fasolo, D.; Serianni, G.; Tollin, M.; Veltri, P.

2017-08-01

Powerful neutral beam injectors (NBI) are required as heating and current drive systems for tokamaks like ITER. The development of negative ion sources and accelerators (40 A; 1 MeV D- beam) in particular, is a crucial point and many issues still require a better understanding. In this framework, the experiment NIO1 (9 beamlets of 15 mA H- each, 60 kV) operated at Consorzio RFX started operation in 2014[1]. Both its RF negative ion source (up to 2.5 kW) and its beamline are equipped with many diagnostics [2]. For the early tests on the extraction system, oxygen has been used as well as hydrogen due to its higher electronegativity, which allows reaching currents large enough to test the beam diagnostics even without caesium injection. In particular a 1D-CFC (carbon-fibre-carbon composite) tile is used as a calorimeter to determine the beam power deposition by observing the rear surface of the tile with an infra-red camera; the same design is applied as for STRIKE [3], one of the diagnostics of SPIDER (the ITER-like ion source prototype [4]) whose facility is currently under construction at Consorzio RFX. From this diagnostic it is also possible to assess the beam divergence and thus the beam optics. The present contribution describes the characterization of the NIO1 particle beam by means of temperature and current measurements with different source and accelerator parameters.

In vivo microscopic imaging of the bronchial mucosa using an endo-cytoscopy system.

PubMed

Shibuya, Kiyoshi; Fujiwara, Taiki; Yasufuku, Kazuhiro; Alaa, Mohamed; Chiyo, Masako; Nakajima, Takahiro; Hoshino, Hidehisa; Hiroshima, Kenzo; Nakatani, Yukio; Yoshino, Ichiro

2011-05-01

We investigated the capabilities of an endo-cytoscopy system (ECS) that enables microscopic imaging of the tracheobronchial tree during bronchoscopy, including normal bronchial epithelium, dysplastic mucosa and squamous cell carcinoma. The newly developed ECS has a 3.2 mm diameter that can be passed through the 4.2 mm working channel of a mother endoscope for insertion of the ECS. It has a high magnification of 570× on a 17 in. video monitor. Twenty-two patients (7 squamous cell carcinoma, 11 squamous dysplasia and 4 after PDT therapies) were underwent white light, NBI light and AFI bronchoscopy. Both abnormal areas of interest and normal bronchial mucosa were stained with 0.5% methylene blue and examined with ECS at high magnification (570×). Histological examinations using haematoxylin and eosin staining were made of biopsied specimens. Analyzed ECS images were compared with the corresponding histological examinations. In normal bronchial mucosa, ciliated columnar epithelial cells were visible. In bronchial squamous dysplasia, superficial cells with abundant cytoplasm were arranged regularly. In squamous cell carcinoma, large, polymorphic tumor cells showed increased cellular densities with irregular stratified patterns. These ECS images corresponded well with the light-microscopic examination of conventional histology. ECS was useful for the discrimination between normal bronchial epithelial cells and dysplastic cells or malignant cells during bronchoscopy in real time. This novel technology has an excellent potential to provide in vivo diagnosis during bronchoscopic examinations. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

An algorithmic framework for multiobjective optimization.

PubMed

Ganesan, T; Elamvazuthi, I; Shaari, Ku Zilati Ku; Vasant, P

2013-01-01

Multiobjective (MO) optimization is an emerging field which is increasingly being encountered in many fields globally. Various metaheuristic techniques such as differential evolution (DE), genetic algorithm (GA), gravitational search algorithm (GSA), and particle swarm optimization (PSO) have been used in conjunction with scalarization techniques such as weighted sum approach and the normal-boundary intersection (NBI) method to solve MO problems. Nevertheless, many challenges still arise especially when dealing with problems with multiple objectives (especially in cases more than two). In addition, problems with extensive computational overhead emerge when dealing with hybrid algorithms. This paper discusses these issues by proposing an alternative framework that utilizes algorithmic concepts related to the problem structure for generating efficient and effective algorithms. This paper proposes a framework to generate new high-performance algorithms with minimal computational overhead for MO optimization.

An Algorithmic Framework for Multiobjective Optimization

PubMed Central

Ganesan, T.; Elamvazuthi, I.; Shaari, Ku Zilati Ku; Vasant, P.

2013-01-01

Multiobjective (MO) optimization is an emerging field which is increasingly being encountered in many fields globally. Various metaheuristic techniques such as differential evolution (DE), genetic algorithm (GA), gravitational search algorithm (GSA), and particle swarm optimization (PSO) have been used in conjunction with scalarization techniques such as weighted sum approach and the normal-boundary intersection (NBI) method to solve MO problems. Nevertheless, many challenges still arise especially when dealing with problems with multiple objectives (especially in cases more than two). In addition, problems with extensive computational overhead emerge when dealing with hybrid algorithms. This paper discusses these issues by proposing an alternative framework that utilizes algorithmic concepts related to the problem structure for generating efficient and effective algorithms. This paper proposes a framework to generate new high-performance algorithms with minimal computational overhead for MO optimization. PMID:24470795

Bi-enhanced N incorporation in GaAsNBi alloys

NASA Astrophysics Data System (ADS)

Occena, J.; Jen, T.; Rizzi, E. E.; Johnson, T. M.; Horwath, J.; Wang, Y. Q.; Goldman, R. S.

2017-06-01

We have examined the influence of bismuth (Bi) and nitrogen (N) fluxes on N and Bi incorporation during molecular-beam epitaxy of GaAs1-x-yNxBiy alloys. The incorporation of Bi is found to be independent of N flux, while the total N incorporation and the fraction of N atoms occupying non-substitutional lattice sites increase with increasing Bi flux. A comparison of channeling nuclear reaction analysis along the [100], [110], and [111] directions with Monte Carlo-Molecular Dynamics simulations indicates that the non-substitutional N primarily incorporate as (N-As)As interstitial complexes. We discuss the influence of Bi adatoms on the formation of arsenic-terminated [110]-oriented step-edges and the resulting enhancement in total N incorporation via the formation of additional (N-As)As.

Valbenazine for the treatment of tardive dyskinesia.

PubMed

Barquero, N

2016-12-01

Valbenazine (NBI-98854, Ingrezza) is a highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor that modulates dopamine release during nerve communication. The pharmacological target VMAT2 may play an important role in the treatment of tardive dyskinesia (TD), an iatrogenic condition associated with the administration of antipsychotic medication for long periods and characterized by rapid, repetitive, stereotypic, involuntary movements of the face and extremities. There are currently no Food and Drug Administration (FDA)-approved drugs for the treatment of TD. Results of clinical trials have shown a distinctive improvement in TD symptoms during valbenazine administration and a new drug application submitted to the FDA in August 2016 is undergoing priority review with a decision expected in April 2017. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

Status of the 1 MeV Accelerator Design for ITER NBI

NASA Astrophysics Data System (ADS)

Kuriyama, M.; Boilson, D.; Hemsworth, R.; Svensson, L.; Graceffa, J.; Schunke, B.; Decamps, H.; Tanaka, M.; Bonicelli, T.; Masiello, A.; Bigi, M.; Chitarin, G.; Luchetta, A.; Marcuzzi, D.; Pasqualotto, R.; Pomaro, N.; Serianni, G.; Sonato, P.; Toigo, V.; Zaccaria, P.; Kraus, W.; Franzen, P.; Heinemann, B.; Inoue, T.; Watanabe, K.; Kashiwagi, M.; Taniguchi, M.; Tobari, H.; De Esch, H.

2011-09-01

The beam source of neutral beam heating/current drive system for ITER is needed to accelerate the negative ion beam of 40A with D- at 1 MeV for 3600 sec. In order to realize the beam source, design and R&D works are being developed in many institutions under the coordination of ITER organization. The development of the key issues of the ion source including source plasma uniformity, suppression of co-extracted electron in D beam operation and also after the long beam duration time of over a few 100 sec, is progressed mainly in IPP with the facilities of BATMAN, MANITU and RADI. In the near future, ELISE, that will be tested the half size of the ITER ion source, will start the operation in 2011, and then SPIDER, which demonstrates negative ion production and extraction with the same size and same structure as the ITER ion source, will start the operation in 2014 as part of the NBTF. The development of the accelerator is progressed mainly in JAEA with the MeV test facility, and also the computer simulation of beam optics also developed in JAEA, CEA and RFX. The full ITER heating and current drive beam performance will be demonstrated in MITICA, which will start operation in 2016 as part of the NBTF.

Involvement of CRFR1 in the Basolateral Amygdala in the Immediate Fear Extinction Deficit

PubMed Central

Sevelinges, Yannick; Zanoletti, Olivia

2016-01-01

Abstract Several animal and clinical studies have highlighted the ineffectiveness of fear extinction sessions delivered shortly after trauma exposure. This phenomenon, termed the immediate extinction deficit, refers to situations in which extinction programs applied shortly after fear conditioning may result in the reduction of fear behaviors (in rodents, frequently measured as freezing responses to the conditioned cue) during extinction training, but failure to consolidate this reduction in the long term. The molecular mechanisms driving this immediate extinction resistance remain unclear. Here we present evidence for the involvement of the corticotropin releasing factor (CRF) system in the basolateral amygdala (BLA) in male Wistar rats. Intra-BLA microinfusion of the CRFR1 antagonist NBI30775 enhances extinction recall, whereas administration of the CRF agonist CRF6–33 before delayed extinction disrupts recall of extinction. We link the immediate fear extinction deficit with dephosphorylation of GluA1 glutamate receptors at Ser845 and enhanced activity of the protein phosphatase calcineurin in the BLA. Their reversal after treatment with the CRFR1 antagonist indicates their dependence on CRFR1 actions. These findings can have important implications for the improvement of therapeutic approaches to trauma, as well as furthering our understanding of the neurobiological mechanisms underlying fear-related disorders. PMID:27844053

Involvement of CRFR1 in the Basolateral Amygdala in the Immediate Fear Extinction Deficit.

PubMed

Hollis, Fiona; Sevelinges, Yannick; Grosse, Jocelyn; Zanoletti, Olivia; Sandi, Carmen

2016-01-01

Several animal and clinical studies have highlighted the ineffectiveness of fear extinction sessions delivered shortly after trauma exposure. This phenomenon, termed the immediate extinction deficit, refers to situations in which extinction programs applied shortly after fear conditioning may result in the reduction of fear behaviors (in rodents, frequently measured as freezing responses to the conditioned cue) during extinction training, but failure to consolidate this reduction in the long term. The molecular mechanisms driving this immediate extinction resistance remain unclear. Here we present evidence for the involvement of the corticotropin releasing factor (CRF) system in the basolateral amygdala (BLA) in male Wistar rats. Intra-BLA microinfusion of the CRFR 1 antagonist NBI30775 enhances extinction recall, whereas administration of the CRF agonist CRF 6-33 before delayed extinction disrupts recall of extinction. We link the immediate fear extinction deficit with dephosphorylation of GluA1 glutamate receptors at Ser 845 and enhanced activity of the protein phosphatase calcineurin in the BLA. Their reversal after treatment with the CRFR 1 antagonist indicates their dependence on CRFR 1 actions. These findings can have important implications for the improvement of therapeutic approaches to trauma, as well as furthering our understanding of the neurobiological mechanisms underlying fear-related disorders.

Progress of the ELISE test facility: towards one hour pulses in hydrogen

NASA Astrophysics Data System (ADS)

Wünderlich, D.; Fantz, U.; Heinemann, B.; Kraus, W.; Riedl, R.; Wimmer, C.; the NNBI Team

2016-10-01

In order to fulfil the ITER requirements, the negative hydrogen ion source used for NBI has to deliver a high source performance, i.e. a high extracted negative ion current and simultaneously a low co-extracted electron current over a pulse length up to 1 h. Negative ions will be generated by the surface process in a low-temperature low-pressure hydrogen or deuterium plasma. Therefore, a certain amount of caesium has to be deposited on the plasma grid in order to obtain a low surface work function and consequently a high negative ion production yield. This caesium is re-distributed by the influence of the plasma, resulting in temporal instabilities of the extracted negative ion current and the co-extracted electrons over long pulses. This paper describes experiments performed in hydrogen operation at the half-ITER-size NNBI test facility ELISE in order to develop a caesium conditioning technique for more stable long pulses at an ITER relevant filling pressure of 0.3 Pa. A significant improvement of the long pulse stability is achieved. Together with different plasma diagnostics it is demonstrated that this improvement is correlated to the interplay of very small variations of parameters like the electrostatic potential and the particle densities close to the extraction system.

Development and Characterization of a 16.3 keV X-Ray Source at the National Ignition Facility

NASA Astrophysics Data System (ADS)

Fournier, K. B.; Barrios, M. A.; Schneider, M. B.; Khan, S.; Chen, H.; Coppari, F.; Rygg, R.; Hohenberger, M.; Albert, F.; Moody, J.; Ralph, J.; Kemp, G. E.; Regan, S. P.

2014-10-01

X-ray sources at the National Ignition Facility are needed for radiography of in-flight capsules in inertial confinement fusion experiments and for diffraction studies of materials at high pressures. In the former case, we want to optimize signal to noise and signal over background ratios for the radiograph, in the latter case, we want to minimize high-energy emission from the backlighter that creates background on the diffraction data. Four interleaved shots at NIF were taken in one day, with laser irradiances on a Zr backlighter target ranging from 5 to 14 × 1015 W/cm2. Two shots were for source optimization as a function of laser irradiance. X-ray fluxes were measured with the time-resolved NIF X-ray Spectrometer (NXS) and the DANTE array of calibrated, filtered diodes. Two shots were optimized to make backscatter measurements with the FABS and NBI optical power systems. The backscatter levels are investigated to look for correlation with hot electron populations inferred from high-energy x rays measured with the FFLEX broadband spectrometer. Results from all shots are presented and compared with models. Work performed under the auspices of the U.S. DOE by LLNL under Contract No. DE-AC52-07NA27344.

MHD stability analysis and global mode identification preparing for high beta operation in KSTAR

NASA Astrophysics Data System (ADS)

Park, Y. S.; Sabbagh, S. A.; Berkery, J. W.; Jiang, Y.; Ahn, J. H.; Han, H. S.; Bak, J. G.; Park, B. H.; Jeon, Y. M.; Kim, J.; Hahn, S. H.; Lee, J. H.; Ko, J. S.; in, Y. K.; Yoon, S. W.; Oh, Y. K.; Wang, Z.; Glasser, A. H.

2017-10-01

H-mode plasma operation in KSTAR has surpassed the computed n = 1 ideal no-wall stability limit in discharges exceeding several seconds in duration. The achieved high normalized beta plasmas are presently limited by resistive tearing instabilities rather than global kink/ballooning or RWMs. The ideal and resistive stability of these plasmas is examined by using different physics models. The observed m/ n = 2/1 tearing stability is computed by using the M3D-C1 code, and by the resistive DCON code. The global MHD stability modified by kinetic effects is examined using the MISK code. Results from the analysis explain the stabilization of the plasma above the ideal MHD no-wall limit. Equilibrium reconstructions used include the measured kinetic profiles and MSE data. In preparation for plasma operation at higher beta utilizing the planned second NBI system, three sets of 3D magnetic field sensors have been installed and will be used for RWM active feedback control. To accurately determine the dominant n-component produced by low frequency unstable RWMs, an algorithm has been developed that includes magnetic sensor compensation of the prompt applied field and the field from the induced current on the passive conductors. Supported by US DOE Contracts DE-FG02-99ER54524 and DE-SC0016614.

Insights Into Upland Cotton (Gossypium hirsutum L.) Genetic Recombination Based on 3 High-Density Single-Nucleotide Polymorphism and a Consensus Map Developed Independently With Common Parents.

PubMed

Ulloa, Mauricio; Hulse-Kemp, Amanda M; De Santiago, Luis M; Stelly, David M; Burke, John J

2017-01-01

High-density linkage maps are vital to supporting the correct placement of scaffolds and gene sequences on chromosomes and fundamental to contemporary organismal research and scientific approaches to genetic improvement, especially in paleopolyploids with exceptionally complex genomes, eg, upland cotton ( Gossypium hirsutum L., "2n = 52"). Three independently developed intraspecific upland mapping populations were analyzed to generate 3 high-density genetic linkage single-nucleotide polymorphism (SNP) maps and a consensus map using the CottonSNP63K array. The populations consisted of a previously reported F 2 , a recombinant inbred line (RIL), and reciprocal RIL population, from "Phytogen 72" and "Stoneville 474" cultivars. The cluster file provided 7417 genotyped SNP markers, resulting in 26 linkage groups corresponding to the 26 chromosomes (c) of the allotetraploid upland cotton (AD) 1 arisen from the merging of 2 genomes ("A" Old World and "D" New World). Patterns of chromosome-specific recombination were largely consistent across mapping populations. The high-density genetic consensus map included 7244 SNP markers that spanned 3538 cM and comprised 3824 SNP bins, of which 1783 and 2041 were in the A t and D t subgenomes with 1825 and 1713 cM map lengths, respectively. Subgenome average distances were nearly identical, indicating that subgenomic differences in bin number arose due to the high numbers of SNPs on the D t subgenome. Examination of expected recombination frequency or crossovers (COs) on the chromosomes within each population of the 2 subgenomes revealed that COs were also not affected by the SNPs or SNP bin number in these subgenomes. Comparative alignment analyses identified historical ancestral A t -subgenomic translocations of c02 and c03, as well as of c04 and c05. The consensus map SNP sequences aligned with high congruency to the NBI assembly of Gossypium hirsutum . However, the genomic comparisons revealed evidence of additional unconfirmed possible duplications, inversions and translocations, and unbalance SNP sequence homology or SNP sequence/loci genomic dominance, or homeolog loci bias of the upland tetraploid A t and D t subgenomes. The alignments indicated that 364 SNP-associated previously unintegrated scaffolds can be placed in pseudochromosomes of the NBI G hirsutum assembly. This is the first intraspecific SNP genetic linkage consensus map assembled in G hirsutum with a core of reproducible mendelian SNP markers assayed on different populations and it provides further knowledge of chromosome arrangement of genic and nongenic SNPs. Together, the consensus map and RIL populations provide a synergistically useful platform for localizing and identifying agronomically important loci for improvement of the cotton crop.

Physics Results from the National Spherical Torus Experiment

NASA Astrophysics Data System (ADS)

Kaye, S. M.

2000-10-01

The National Spherical Torus Experiment (NSTX) will produce plasmas with R/a=0.85/0.68 m 1.25, I_p= 1 MA, BT <=0.6 T, κ<=2.2, δ<=0.5, with 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI) and Co-axial Helicity Injection (CHI) for non-inductive startup to establish the physics principles of low aspect ratio. Outboard passive conducting plates aid vertical stability and suppression of low-n modes. During the initial set of physics experiments, studies of poloidal flux consumption indicated an optimal current ramp rate of 5 MA/sec, with higher ramp rates limited by m=2 oscillations and Internal Reconnection Events possibly related to impurity accumulation and double tearing modes. Flux consumption optimization and real-time plasma control led to the achievement of ohmic discharges with 1 MA plasma current and stored energies up to 48 kJ and βT 9%. Inboard limited and single and double-null diverted plasmas over a wide range of κ and δ were produced. The density limit, so far, is consistent with the Hugill limit, which is about 60% of the Greenwald limit, and it was characterized by growing and locking m=1 oscillations, followed by a series of Reconnection Events. The q-limit was manifest as growing and locking 2/1 perturbations leading to severe kinking of the plasma surface and subsequent discharge termination as q_cyl decreased below 2. Initial observations of edge turbulence indicated filamentary structures with λ_perp 10 cm. Up to 2 MW of HHFW power was coupled to the plasma, with increases in stored energy observed for waves with k_parallel=14 m-1, but not at higher phase velocity. CHI experiments on NSTX produced up to 130 kA of toroidal current for up to 100 msec. NBI heating is planned for late September 2000. This work has been supported at PPPL by U.S. DOE Contract # DE-AC02-76CH03073.

Endocytoscopic findings of lymphomas of the stomach

PubMed Central

2013-01-01

Background The gastric lesions of various lymphomas were observed at the cellular level using endocytoscopy. Methods Endocytoscopy and magnifying endoscopy with narrow band imaging (NBI) were performed in 17 patients with lymphomas of the stomach. The lesions consisted of 7 with low-grade mucosa-associated lymphoid tissue (MALT), 5 with gastric involvement by adult T-cell leukemia/lymphoma (ATLL), 4 with diffuse large B-cell lymphoma (DLBCL), and 1 with peripheral T-cell lymphoma. Results On conventional endoscopy, 9 were classified as having superficial spreading type, 7 were mass-forming type, and 1 was diffuse infiltrating type. Anti-H. pylori treatment was given in the 7 MALT lymphoma cases. NBI magnification endoscopy invariably showed dilatation or ballooning and destruction of gastric pits and elongation and distortion in microvessels. Endocytoscopy showed mucosal aggregation of interstitial cellular elements in almost all gastric lymphoma cases. The nuclear diversity in size and configuration was exclusively seen in gastric lymphomas other than MALT lymphoma, whereas the nuclei of MALT lymphoma cells were regular and small to moderate in size. Inter-glandular infiltration by lymphomatous cell elements was frequently observed in MALT lymphoma and DLBCL, but it was uncommon in peripheral gastric T-cell malignancies. Endocytoscopy could identify the disease-specific histology, the lymphoepithelial origin, as inter-glandular infiltration of cellular components in MALT lymphoma and the possibly related DLBCL cases. Complete regression (CR) was observed in 2 of the 7 MALT lymphoma patients. In the 2 patients with CR who underwent repeat endocytoscopy, the ultra-high magnification abnormalities returned to normal, while they were unchanged in those without tumor regression. Conclusions On endocytoscopy, intra-glandular aggregation of cellular components was invariably identified in lymphomas of the stomach. Nuclear regularity in size and configuration may indicate the cytological grade, differentiating the indolent low-grade from aggressive lymphoproliferative diseases. The inter-glandular infiltration seen on endocytoscopy can indicate the lymphoepithelial lesions seen in MALT lymphoma and related DLBCL. Endocytoscopy would be applicable for virtual histopathological diagnosis of different lymphoproliferative disorders and their clinical assessment during ongoing endoscopy. PMID:24369830

Behavioral, biological, and chemical perspectives on targeting CRF1 receptor antagonists to treat alcoholism

PubMed Central

Zorrilla, Eric P.; Heilig, Markus; de Wit, Harriet; Shaham, Yavin

2013-01-01

Background Alcohol use disorders are chronic disabling conditions for which existing pharmacotherapies have only modest efficacy. In the present review, derived from the 2012 Behavior, Biology and Chemistry “Translational Research in Addiction” symposium, we summarize the anti-relapse potential of corticotropin-releasing factor type 1 (CRF1) receptor antagonists to reduce negative emotional symptoms of acute and protracted alcohol withdrawal and stress-induced relapse to alcohol seeking. Methods We review the biology of CRF1 systems, the activity of CRF1 receptor antagonists in animal models of anxiolytic and antidepressant activity, and experimental findings in alcohol addiction models. We also update the clinical trial status of CRF1 receptor antagonists, including pexacerfont (BMS-562086), emicerfont (GW876008), verucerfont (GSK561679), CP316311, SSR125543A, R121919/NBI30775, R317573/19567470/CRA5626, and ONO-2333Ms. Finally, we discuss the potential heterogeneity and pharmacogenomics of CRF1 receptor pharmacotherapy for alcohol dependence. Results The evidence suggests that brain penetrant-CRF1 receptor antagonists have therapeutic potential for alcohol dependence. Lead compounds with clinically desirable pharmacokinetic properties now exist, and longer receptor residence rates (i.e., slow dissociation) may predict greater CRF1 receptor antagonist efficacy. Functional variants in genes that encode CRF system molecules, including polymorphisms in Crhr1 (rs110402, rs1876831, rs242938) and Crhbp genes (rs10055255, rs3811939) may promote alcohol seeking and consumption by altering basal or stress-induced CRF system activation. Conclusions Ongoing clinical trials with pexacerfont and verucerfont in moderately to highly severe dependent anxious alcoholics may yield insight as to the role of CRF1 receptor antagonists in a personalized medicine approach to treat drug or alcohol dependence. PMID:23294766

Transmission of electrons inside the cryogenic pumps of ITER injector.

PubMed

Veltri, P; Sartori, E

2016-02-01

Large cryogenic pumps are installed in the vessel of large neutral beam injectors (NBIs) used to heat the plasma in nuclear fusion experiments. The operation of such pumps can be compromised by the presence of stray secondary electrons that are generated along the beam path. In this paper, we present a numerical model to analyze the propagation of the electrons inside the pump. The aim of the study is to quantify the power load on the active pump elements, via evaluation of the transmission probabilities across the domain of the pump. These are obtained starting from large datasets of particle trajectories, obtained by numerical means. The transmission probability of the electrons across the domain is calculated for the NBI of the ITER and for its prototype Megavolt ITer Injector and Concept Advancement (MITICA) and the results are discussed.

Analysis of activation and shutdown contact dose rate for EAST neutral beam port

NASA Astrophysics Data System (ADS)

Chen, Yuqing; Wang, Ji; Zhong, Guoqiang; Li, Jun; Wang, Jinfang; Xie, Yahong; Wu, Bin; Hu, Chundong

2017-12-01

For the safe operation and maintenance of neutral beam injector (NBI), specific activity and shutdown contact dose rate of the sample material SS316 are estimated around the experimental advanced superconducting tokamak (EAST) neutral beam port. Firstly, the neutron emission intensity is calculated by TRANSP code while the neutral beam is co-injected to EAST. Secondly, the neutron activation and shutdown contact dose rates for the neutral beam sample materials SS316 are derived by the Monte Carlo code MCNP and the inventory code FISPACT-2007. The simulations indicate that the primary radioactive nuclides of SS316 are 58Co and 54Mn. The peak contact dose rate is 8.52 × 10-6 Sv/h after EAST shutdown one second. That is under the International Thermonuclear Experimental Reactor (ITER) design values 1 × 10-5 Sv/h.

"Snowflake" divertor configuration in NSTX

NASA Astrophysics Data System (ADS)

Soukhanovskii, V. A.; Ahn, J.-W.; Bell, R. E.; Gates, D. A.; Gerhardt, S.; Kaita, R.; Kolemen, E.; Kugel, H. W.; Leblanc, B. P.; Maingi, R.; Maqueda, R.; McLean, A.; Menard, J. E.; Mueller, D. M.; Paul, S. F.; Raman, R.; Roquemore, A. L.; Ryutov, D. D.; Scott, H. A.

2011-08-01

Steady-state handling of divertor heat flux is a critical issue for present and future conventional and spherical tokamaks with compact high power density divertors. A novel "snowflake" divertor (SFD) configuration that takes advantage of magnetic properties of a second-order poloidal null has been predicted to have a larger plasma-wetted area and a larger divertor volume, in comparison with a standard first-order poloidal X-point divertor configuration. The SFD was obtained in 0.8 MA, 4-6 MW NBI-heated H-mode discharges in NSTX using two divertor magnetic coils. The SFD led to a partial detachment of the outer strike point even in low-collisionality scrape-off layer plasma obtained with lithium coatings in NSTX. Significant divertor peak heat flux reduction and impurity screening have been achieved simultaneously with good core confinement and MHD properties.

Bi-enhanced N incorporation in GaAsNBi alloys

DOE PAGES

Occena, J.; Jen, T.; Rizzi, E. E.; ...

2017-06-12

We have examined the influence of bismuth (Bi) and nitrogen (N) fluxes on N and Bi incorporation during molecular-beam epitaxy of GaAs 1-x-yN xBi y alloys. The incorporation of Bi is found to be independent of N flux, while the total N incorporation and the fraction of N atoms occupying non-substitutional lattice sites increase with increasing Bi flux. A comparison of channeling nuclear reaction analysis along the [100], [110], and [111] directions with Monte Carlo-Molecular Dynamics simulations indicates that the non-substitutional N primarily incorporate as (N-As) As interstitial complexes. We discuss the influence of Bi adatoms on the formation ofmore » arsenic-terminated [110]-oriented step-edges and the resulting enhancement in total N incorporation via the formation of additional (N-As) As.« less

Neonatal isolation delays the developmental decline of long-term depression in the CA1 region of rat hippocampus.

PubMed

Ku, Hsiao-Yun; Huang, Yu-Fei; Chao, Pei-Hsuan; Huang, Chiung-Chun; Hsu, Kuei-Sen

2008-11-01

Activity-dependent alterations of synaptic efficacy or connectivity are essential for the development, signal processing, and learning and memory functions of the nervous system. It was observed that, in particular in the CA1 region of the hippocampus, low-frequency stimulation (LFS) became progressively less effective at inducing long-term depression (LTD) with advancing developmental age. The physiological factors regulating this developmental plasticity change, however, have not yet been elucidated. Here we examined the hypothesis that neonatal isolation (once per day for 1 h from postnatal days 1-7) is able to alter processes underlying the developmental decline of LTD. We confirm that the magnitude of LTD induced by LFS (900 stimuli at 1 Hz) protocol correlates negatively with developmental age and illustrates that neonatal isolation delays this developmental decline via the activation of corticotrophin-releasing factor (CRF) system. Furthermore, this modulation appears to be mediated by an increased transcription of N-methyl-D-aspartate receptor NR2B subunits. We also demonstrate that intracerebroventricular injection of CRF postnatally mimicked the effect of neonatal isolation to increase the expression of NR2B subunits and delayed the developmental decline of LTD, which was specifically blocked by CRF receptor 1 antagonist NBI27914 pretreatment. These results suggest a novel role for CRF in regulating developmental events in the hippocampus and indicate that although maternal deprivation is stressful for neonate, appropriate neonatal isolation can serve to promote an endocrine state that may regulate the gradual developmental change in the induction rules for synaptic plasticity in the hippocampal CA1 region.

Neoclassical parallel flow calculation in the presence of external parallel momentum sources in Heliotron J

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishioka, K.; Nakamura, Y.; Nishimura, S.

A moment approach to calculate neoclassical transport in non-axisymmetric torus plasmas composed of multiple ion species is extended to include the external parallel momentum sources due to unbalanced tangential neutral beam injections (NBIs). The momentum sources that are included in the parallel momentum balance are calculated from the collision operators of background particles with fast ions. This method is applied for the clarification of the physical mechanism of the neoclassical parallel ion flows and the multi-ion species effect on them in Heliotron J NBI plasmas. It is found that parallel ion flow can be determined by the balance between themore » parallel viscosity and the external momentum source in the region where the external source is much larger than the thermodynamic force driven source in the collisional plasmas. This is because the friction between C{sup 6+} and D{sup +} prevents a large difference between C{sup 6+} and D{sup +} flow velocities in such plasmas. The C{sup 6+} flow velocities, which are measured by the charge exchange recombination spectroscopy system, are numerically evaluated with this method. It is shown that the experimentally measured C{sup 6+} impurity flow velocities do not contradict clearly with the neoclassical estimations, and the dependence of parallel flow velocities on the magnetic field ripples is consistent in both results.« less

Transmission of electrons inside the cryogenic pumps of ITER injector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veltri, P., E-mail: pierluigi.veltri@igi.cnr.it; Sartori, E.

2016-02-15

Large cryogenic pumps are installed in the vessel of large neutral beam injectors (NBIs) used to heat the plasma in nuclear fusion experiments. The operation of such pumps can be compromised by the presence of stray secondary electrons that are generated along the beam path. In this paper, we present a numerical model to analyze the propagation of the electrons inside the pump. The aim of the study is to quantify the power load on the active pump elements, via evaluation of the transmission probabilities across the domain of the pump. These are obtained starting from large datasets of particlemore » trajectories, obtained by numerical means. The transmission probability of the electrons across the domain is calculated for the NBI of the ITER and for its prototype Megavolt ITer Injector and Concept Advancement (MITICA) and the results are discussed.« less

ELM suppression in helium plasmas with 3D magnetic fields

DOE PAGES

Evans, T. E.; Loarte, A.; Orlov, D. M.; ...

2017-06-21

Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L–H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER's non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n = 3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction andmore » an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. Here, the change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.« less

Extension of operational regime in high-temperature plasmas and effect of ECRH on ion thermal transport in the LHD

NASA Astrophysics Data System (ADS)

Takahashi, H.; Nagaoka, K.; Murakami, S.; Osakabe, M.; Nakano, H.; Ida, K.; Tsujimura, T. I.; Kubo, S.; Kobayashi, T.; Tanaka, K.; Seki, R.; Takeiri, Y.; Yokoyama, M.; Maeta, S.; Nakata, M.; Yoshinuma, M.; Yamada, I.; Yasuhara, R.; Ido, T.; Shimizu, A.; Tsuchiya, H.; Tokuzawa, T.; Goto, M.; Oishi, T.; Morita, S.; Suzuki, C.; Emoto, M.; Tsumori, K.; Ikeda, K.; Kisaki, M.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Makino, R.; Seki, T.; Kasahara, H.; Saito, K.; Kamio, S.; Nagasaki, K.; Mutoh, T.; Kaneko, O.; Morisaki, T.; the LHD Experiment Group

2017-08-01

A simultaneous high ion temperature (T i) and high electron temperature (T e) regime was successfully extended due to an optimized heating scenario in the LHD. Such high-temperature plasmas were realized by the simultaneous formation of an electron internal transport barrier (ITB) and an ion ITB by the combination of high power NBI and ECRH. Although the ion thermal confinement was degraded in the plasma core with an increase of T e/T i by the on-axis ECRH, it was found that the ion thermal confinement was improved at the plasma edge. The normalized ion thermal diffusivity {χ\\text{i}}/T\\text{i}1.5 at the plasma edge was reduced by 70%. The improvement of the ion thermal confinement at the edge led to an increase in T i in the entire plasma region, even though the core transport was degraded.

Technological advances for improving adenoma detection rates: The changing face of colonoscopy.

PubMed

Ishaq, Sauid; Siau, Keith; Harrison, Elizabeth; Tontini, Gian Eugenio; Hoffman, Arthur; Gross, Seth; Kiesslich, Ralf; Neumann, Helmut

2017-07-01

Worldwide, colorectal cancer is the third commonest cancer. Over 90% follow an adenoma-to-cancer sequence over many years. Colonoscopy is the gold standard method for cancer screening and early adenoma detection. However, considerable variation exists between endoscopists' detection rates. This review considers the effects of different endoscopic techniques on adenoma detection. Two areas of technological interest were considered: (1) optical technologies and (2) mechanical technologies. Optical solutions, including FICE, NBI, i-SCAN and high definition colonoscopy showed mixed results. In contrast, mechanical advances, such as cap-assisted colonoscopy, FUSE, EndoCuff and G-EYE™, showed promise, with reported detections rates of up to 69%. However, before definitive recommendations can be made for their incorporation into daily practice, further studies and comparison trials are required. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

ELM suppression in helium plasmas with 3D magnetic fields

NASA Astrophysics Data System (ADS)

Evans, T. E.; Loarte, A.; Orlov, D. M.; Grierson, B. A.; Knölker, M. M.; Lyons, B. C.; Cui, L.; Gohil, P.; Groebner, R. J.; Moyer, R. A.; Nazikian, R.; Osborne, T. H.; Unterberg, E. A.

2017-08-01

Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L-H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER’s non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n  =  3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction and an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. The change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.

Individual Sawtooth Pacing by Synchronized ECCD in TCV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodman, T. P.; Felici, F.; Canal, G.

2011-12-23

Previous real-time sawtooth control scenarios using EC actuators have attempted to shorten or lengthen the sawtooth period by optimally positioning the EC absorption near the q = 1 surface. In new experiments we demonstrate for the first time that individual sawtooth crashes can be repetitively induced at predictable times by reducing the stabilizing ECCD power after a predetermined time from the preceding crash. Other stabilizing actuators (e.g. ICRF, NBI) are expected to produce similar effects. Armed with these results, we present a new sawtooth / NTM control paradigm for improved performance in burning plasmas. The potential appearance of neo-classical tearingmore » modes, triggered by long period sawtooth crashes even at low beta, becomes predictable and therefore amenable to preemptive ECCD. The ITER Electron Cyclotron Upper Launcher (EC-UL) design incorporates the needed functionalities for this method to be applied. The methodology and associated TCV experiments will be presented.« less

Wartime critical care air transport.

PubMed

Bridges, Elizabeth; Evers, Karen

2009-04-01

Describe the characteristics/enroute care of casualties transported by USAF Critical Care Air Transport Teams (CCATT) during Operation Enduring Freedom/Iraqi Freedom (OEF/OIF). Retrospective review of TRAC2ES and CCATT Mission Reports (Oct 2001-May 2006). 3492 patient moves (2439 patients). Moves by route: within Area of Responsibility (AOR) (n = 261); AOR-Landstuhl (LRMC) (n = 1995), Germany-CONUS (n = 1188). For AOR-LRMC: BI (64%), NBI (8%), Disease (25%). Among injured (n = 1491), 69% suffered polytrauma, primarily d/t explosions. Injury area: extremities (63%), head (55%), thorax (46%), abdomen (31%), neck (17%). Injury type: soft tissue (64%), orthopedic (45%), thoracic (35%), skull fracture (27%), brain injury (25%). Disease diagnoses: cardiac (15%) and pulmonary (8%). This is the first analysis of OEF/OIF CCATT patients. Phase 1 of this study demonstrates the strengths and limitations of TRAC2ES and CCATT Mission Reports to describe the characteristics/enroute care of this unique population.

Kinetic equilibrium reconstruction for the NBI- and ICRH-heated H-mode plasma on EAST tokamak

NASA Astrophysics Data System (ADS)

Zhen, ZHENG; Nong, XIANG; Jiale, CHEN; Siye, DING; Hongfei, DU; Guoqiang, LI; Yifeng, WANG; Haiqing, LIU; Yingying, LI; Bo, LYU; Qing, ZANG

2018-04-01

The equilibrium reconstruction is important to study the tokamak plasma physical processes. To analyze the contribution of fast ions to the equilibrium, the kinetic equilibria at two time-slices in a typical H-mode discharge with different auxiliary heatings are reconstructed by using magnetic diagnostics, kinetic diagnostics and TRANSP code. It is found that the fast-ion pressure might be up to one-third of the plasma pressure and the contribution is mainly in the core plasma due to the neutral beam injection power is primarily deposited in the core region. The fast-ion current contributes mainly in the core region while contributes little to the pedestal current. A steep pressure gradient in the pedestal is observed which gives rise to a strong edge current. It is proved that the fast ion effects cannot be ignored and should be considered in the future study of EAST.

DFT investigation of electronic structures and magnetic properties of halides family MeHal3 (Me=Ti, Mo,Zr,Nb, Ru, Hal=Cl,Br,I) one dimensional structures

NASA Astrophysics Data System (ADS)

Kuzubov, A. A.; Kovaleva, E. A.; Popova, M. I.; Kholtobina, A. S.; Mikhaleva, N. S.; Visotin, M. A.; Fedorov, A. S.

2017-10-01

Using DFT GGA calculations, electronic structure and magnetic properties of wide family of transition metal trihalides (TMHal3) (Zr, Ti and Nb iodides, Mo, Ru, Ti and Zr bromides and Ti or Zr chlorides) are investigated. These structures consist of transition metal atoms chains surrounded by halides atoms. Chains are connected to each other by weak interactions. All TMHal3 compounds were found to be conductive along chain axis except of MoBr3 which is indirect gap semiconductor. It was shown that NbI3 and MoBr3 have large magnetic moments on metal atoms (1.17 and 1.81 μB, respectively) but other TMHal3 materials have small or zero magnetic moments. For all structures ferromagnetic and anti-ferromagnetic phases have almost the same energies. The causes of these properties are debated.

Nonlinear MHD study on the influence of E×B flow in QH-mode plasma of DIII-D

NASA Astrophysics Data System (ADS)

Liu, Feng; Huijsmans, Guido; Loarte, Alberto; Garofalo, Andrea; Solomon, Wayne; Nkonga, Boniface; Hoelzl, Matthias

2017-10-01

In QH-mode experiments with zero-net NBI torque show that there remains a finite E×B rotation in the pedestal region implying that a minimum E×B flow or flow shear is required for the plasma to develop the Edge Harmonic Oscillation (EHO), which is a saturated KPM (kink-peeling mode) characteristic of the QH-mode. To understand the roles of E×B flow and its shear in the saturation of KPMs, non-linear MHD simulations of DIII-D QH-mode plasmas including toroidal mode numbers n = 0 to 10 with different E×B rotation speed have been performed. These simulation show that ExB rotation strongly stabilizes high-n modes but destabilizes low-n modes (particularly the n =2 mode) in the linear growth phase, which is consistent experimental observations and previous linear MHD modelling. US DOE under DE-FC02-04ER54698.

Commissioning and experimental validation of SST-1 plasma facing components

NASA Astrophysics Data System (ADS)

Paravastu, Yuvakiran; Raval, Dilip; Khan, Ziauddin; Patel, Hitesh; Biswas, Prabal; Parekh, Tejas; George, Siju; Santra, Prosenjit; Ramesh, Gattu; ArunPrakash, A.; Thankey, Prashant; Semwal, Pratibha; Dhanani, Kalpeshkumar R.; Jaiswal, Snehal; Chauhan, Pradeep; Pradhan, Subrata

2017-04-01

Plasma facing components of SST-1 are designed to withstand an input heat load of 1.0 MW/m2. They protect vacuum vessel, auxiliary heating source i.e. RF antennas, NBI and other in-vessel diagnostic from the plasma particles and high radiative heat loads. PFC’s are positioned symmetric to mid-plane to accommodate with circular, single and double null configuration. Graphite is used as plasma facing material, back made of copper alloy and SS cooling/baking tubes are brazed on copper alloy back plates for efficient heat removal of incident heat flux. Benchmarking of PFC assembly was first carried out in prototype vacuum vessel of SST-1 to develop understanding and methodology of co-ordinate measurements. Based on such hands-on-experience, the final assembly of PFC’s in vacuum vessel of SST-1 was carried out. Initially, PFC’s are to be baked at 250 °C for wall conditioning followed with cooling for heat removal of incident heat flux during long pulse plasma operation. For this purpose, the supply and return headers are designed and installed inside the vacuum vessel in such a way that it will cater water as well as hot nitrogen gas depending up on the cycle. This paper will discuss the successful installation of PFC’s and its plasma operation respecting all design criteria.

A generally applicable lightweight method for calculating a value structure for tools and services in bioinformatics infrastructure projects.

PubMed

Mayer, Gerhard; Quast, Christian; Felden, Janine; Lange, Matthias; Prinz, Manuel; Pühler, Alfred; Lawerenz, Chris; Scholz, Uwe; Glöckner, Frank Oliver; Müller, Wolfgang; Marcus, Katrin; Eisenacher, Martin

2017-10-30

Sustainable noncommercial bioinformatics infrastructures are a prerequisite to use and take advantage of the potential of big data analysis for research and economy. Consequently, funders, universities and institutes as well as users ask for a transparent value model for the tools and services offered. In this article, a generally applicable lightweight method is described by which bioinformatics infrastructure projects can estimate the value of tools and services offered without determining exactly the total costs of ownership. Five representative scenarios for value estimation from a rough estimation to a detailed breakdown of costs are presented. To account for the diversity in bioinformatics applications and services, the notion of service-specific 'service provision units' is introduced together with the factors influencing them and the main underlying assumptions for these 'value influencing factors'. Special attention is given on how to handle personnel costs and indirect costs such as electricity. Four examples are presented for the calculation of the value of tools and services provided by the German Network for Bioinformatics Infrastructure (de.NBI): one for tool usage, one for (Web-based) database analyses, one for consulting services and one for bioinformatics training events. Finally, from the discussed values, the costs of direct funding and the costs of payment of services by funded projects are calculated and compared. © The Author 2017. Published by Oxford University Press.

Developing physics basis for the snowflake divertor in the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Soukhanovskii, V. A.; Allen, S. L.; Fenstermacher, M. E.; Lasnier, C. J.; Makowski, M. A.; McLean, A. G.; Meyer, W. H.; Ryutov, D. D.; Kolemen, E.; Groebner, R. J.; Hyatt, A. W.; Leonard, A. W.; Osborne, T. H.; Petrie, T. W.; Watkins, J.

2018-03-01

Recent DIII-D results demonstrate that the snowflake (SF) divertor geometry (see standard divertor) enables significant manipulation of divertor heat transport for heat spreading and reduction in attached and radiative divertor regimes, between and during edge localized modes (ELMs), while maintaining good H-mode confinement. Snowflake divertor configurations have been realized in the DIII-D tokamak for several seconds in H-mode discharges with heating power P_NBI ≤slant 4 -5 MW and a range of plasma currents I_p=0.8-1.2 MA. In this work, inter-ELM transport and radiative SF divertor properties are studied. Significant impact of geometric properties on SOL and divertor plasma parameters, including increased poloidal magnetic flux expansion, divertor magnetic field line length and divertor volume, is confirmed. In the SF-minus configuration, heat deposition is affected by the geometry, and peak divertor heat fluxes are significantly reduced. In the SF-plus and near-exact SF configurations, divertor peak heat flux reduction and outer strike point heat flux profile broadening are observed. Inter-ELM sharing of power and particle fluxes between the main and additional snowflake divertor strike points has been demonstrated. The additional strike points typically receive up to 10-15% of total outer divertor power. Measurements of electron pressure and poloidal beta βp support the theoretically proposed churning mode that is driven by toroidal curvature and vertical pressure gradient in the weak poloidal field region. A comparison of the 4-4.5 MW NBI-heated H-mode plasmas with radiative SF divertor and the standard radiative divertor (both induced with additional gas puffing) shows a nearly complete power detachment and broader divertor radiated power distribution in the SF, as compared to a partial detachment and peaked localized radiation in the standard divertor. However, insignificant difference in the detachment onset w.r.t. density between the SF and the standard divertor was found. The results complement the initial SF divertor studies conducted in high-power H-mode discharges in the NSTX and DIII-D tokamaks, and, along with snowflake divertor results from TCV and other tokamaks, contribute to the physics basis of the SF divertor as a power exhaust concept for future high power density tokamaks.

Tephra compositions from Late Quaternary volcanoes around the Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Kraus, S.

2009-12-01

Crustal extension and rifting processes opened the Bransfield Strait between the South Shetland Islands and the Antarctic Peninsula during the last 4 Ma. Similar processes on the Peninsula's eastern side are responsible for volcanism along Larsen Rift. There are at least 11 volcanic centers with known or suspected Late Pleistocene / Holocene explosive activity (Fig. 1). Fieldwork was carried out on the islands Deception, Penguin, Bridgeman and Paulet, moreover at Melville Peak (King George Is.) and Rezen Peak (Livingston Is.). Of special importance is the second ever reported visit and sampling at Sail Rock, and the work on never before visited outcrops on the northern slopes and at the summit of Cape Purvis volcano (Fig. 1). The new bulk tephra ICP-MS geochemical data provide a reliable framework to distinguish the individual volcanic centers from each other. According to their Mg-number, Melville Peak and Penguin Island represent the most primitive magma source. Nb/Y ratios higher than 0.67 in combination with elevated Th/Yb and Ta/Yb ratios and strongly enriched LREE seem to be diagnostic to distinguish the volcanoes located along the Larsen Rift from those associated with Bransfield Rift. Sr/Y ratios discriminate between the individual Larsen Rift volcanoes, Paulet Island showing considerably higher values than Cape Purvis volcano. Along Bransfield Rift, Bridgeman Island and Melville Peak have notably lower Nb/Y and much higher Th/Nb than Deception Island, Penguin Island and Sail Rock. The latter displays almost double the Th/Yb ratio as compared to Deception Island, and also much higher LREE enrichment but extraordinarily low Ba/Th, discriminating it from Penguin Island. Such extremely low Ba/Th ratios are also typical for Melville Peak, but for none of the other volcanoes. Penguin Island has almost double the Ba/Th and Sr/Y ratios higher than any other investigated volcano. Whereas the volcanoes located in the northern part of Bransfield Strait have Zr/Hf ratios lower than N-MORB, all other volcanoes including the Larsen Rift centers display Zr/Hf higher than N-MORB. It is expected that the correlation of the new data with published data from tephra layers found in ice, lake and marine sediment cores will contribute to a better constrained timing of individual climatic events identified in the northern Antarctic Peninsula area. Late Quaternary volcanoes around the northern Antarctic Peninsula.

Training of polyp staging systems using mixed imaging modalities.

PubMed

Wimmer, Georg; Gadermayr, Michael; Kwitt, Roland; Häfner, Michael; Tamaki, Toru; Yoshida, Shigeto; Tanaka, Shinji; Merhof, Dorit; Uhl, Andreas

2018-05-04

In medical image data sets, the number of images is usually quite small. The small number of training samples does not allow to properly train classifiers which leads to massive overfitting to the training data. In this work, we investigate whether increasing the number of training samples by merging datasets from different imaging modalities can be effectively applied to improve predictive performance. Further, we investigate if the extracted features from the employed image representations differ between different imaging modalities and if domain adaption helps to overcome these differences. We employ twelve feature extraction methods to differentiate between non-neoplastic and neoplastic lesions. Experiments are performed using four different classifier training strategies, each with a different combination of training data. The specifically designed setup for these experiments enables a fair comparison between the four training strategies. Combining high definition with high magnification training data and chromoscopic with non-chromoscopic training data partly improved the results. The usage of domain adaptation has only a small effect on the results compared to just using non-adapted training data. Merging datasets from different imaging modalities turned out to be partially beneficial for the case of combining high definition endoscopic data with high magnification endoscopic data and for combining chromoscopic with non-chromoscopic data. NBI and chromoendoscopy on the other hand are mostly too different with respect to the extracted features to combine images of these two modalities for classifier training. Copyright © 2018 Elsevier Ltd. All rights reserved.

Axisymmetric oscillations at L-H transitions in JET: M-mode

NASA Astrophysics Data System (ADS)

Solano, Emilia R.; Vianello, N.; Delabie, E.; Hillesheim, J. C.; Buratti, P.; Réfy, D.; Balboa, I.; Boboc, A.; Coelho, R.; Sieglin, B.; Silburn, S.; Drewelow, P.; Devaux, S.; Dodt, D.; Figueiredo, A.; Frassinetti, L.; Marsen, S.; Meneses, L.; Maggi, C. F.; Morris, J.; Gerasimov, S.; Baruzzo, M.; Stamp, M.; Grist, D.; Nunes, I.; Rimini, F.; Schmuck, S.; Lupelli, I.; Silva, C.; contributors, JET

2017-02-01

L to H transition studies at JET have revealed an n  =  0, m  =  1 magnetic oscillation starting immediately at the L to H transition (called M-mode for brevity). While the magnetic oscillation is present a weak ELM-less H-mode regime is obtained, with a clear increase of density and a weak electron temperature pedestal. It is an intermediate state between L and H-mode. In ICRH heated plasmas or low density NBI plasmas the magnetic mode and the pedestal can remain steady (with small oscillations) for the duration of the heating phase, of order 10 s or more. The axisymmetric magnetic oscillation has period ~0.5-2 ms, and poloidal mode number m  =  1: it looks like a pedestal localised up/down oscillation, although it is clearly a natural oscillation of the plasma, not driven by the position control system. Electron cyclotron emission, interferometry, reflectometry and fast Li beam measurements locate the mode in the pedestal region. D α , fast infrared camera and Langmuir probe measurements show that the mode modulates heat and particle fluxes to the target. The mode frequency appears to scale with the poloidal Alfvén velocity, and not with sound speed (i.e. it is not a geodesic acoustic mode). A heuristic model is proposed for the frequency scaling of the mode. We discuss the relationship between the M-mode and other related observations near the L-H transition.

Formation of the internal transport barrier in KSTAR

NASA Astrophysics Data System (ADS)

Chung, J.; Kim, H. S.; Jeon, Y. M.; Kim, J.; Choi, M. J.; Ko, J.; Lee, K. D.; Lee, H. H.; Yi, S.; Kwon, J. M.; Hahn, S.-H.; Ko, W. H.; Lee, J. H.; Yoon, S. W.

2018-01-01

One of key objectives of tokamak experiments is the exploration of enhanced confinement regimes, and the access of the internal transport barrier (ITB) formation is dealt with an important physics issue in the most of major tokamaks. Also, the advanced tokamak scenario with ITB is expected to lead to a continuous reactor with high fusion power density. From that point of view, the formation of the ITB in KSTAR which is designed for long pulse operation capability is very important although its heating and current drive systems are not fully equipped yet. We have therefore assumed that an early injection of the full NBI power (∼5.5 MW) during the current ramp-up would give a chance to form an internal barrier if the plasma could stay in the L-mode. To avoid the H-mode transition, we have produced inboard limited plasmas with detaching from the both upper and lower divertors. Using this approach, an ITB formation during L-mode has been observed which shows improved core confinement. Ion and electron temperature profiles show the barrier clearly in the temperature, and it was sustained for about 7 s in the dedicated experiment. This is the first stationary ITB observed in a full superconducting tokamak. This operation scenario with the ITB could be an alternative way to achieve a high performance regime in KSTAR, and the length of the ITB discharge could be extended even longer. In this paper, we present the formation of the ITB using measured and simulated characteristic profiles.

Ohmic ignition with high engineering beta based on the RFP

NASA Astrophysics Data System (ADS)

Sarff, J. S.; Anderson, J. K.; Chapman, B. E.; McCollam, K. J.

2017-10-01

The RFP configuration allows the possibility of ohmic ignition for fusion energy, eliminating the need for auxiliary heating by rf or neutral beam injection. Complex plasma-facing antennas and NBI sources are therefore not required, simplifying the difficult fusion materials challenge. While all toroidal configurations require a volume-average 〈 B 〉 >= 5 T, the field strength at the magnet in the RFP is only Bcoil 3T since plasma current generates almost all of the field. Engineering beta is therefore maximized. We summarize access to ohmic ignition by examining a Lawson-like power balance for an RFP fusion plasma comparable to the ARIES-AT advanced tokamak, which generates neutron wall loading Pn / A 5 MW/m2. The required energy confinement for ohmic ignition in an RFP is similar to that for a tokamak. Confinement in MST is comparable to a same-size, same-field tokamak plasma, but 〈 B 〉 in MST is only 1/20th that required for fusion. While transport could ultimately be dominated by micro turbulence, extrapolation of stochastic transport using Lundquist number scaling for MHD tearing indicates standard RFP confinement (not enhanced by current profile control) could be sufficient to access ohmic ignition. This bolsters the possibility for steady-state inductive sustainment using oscillating field current drive. The high beta and classical energetic ion confinement measured in MST also bolster the RFP's fusion potential. Work supported by U.S. DoE.

Beam characterization at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

NASA Astrophysics Data System (ADS)

Aza, E.; Schiesko, L.; Wimmer, C.; Wünderlich, D.; Fantz, U.

2017-08-01

The properties of the negative hydrogen ion beam produced by the scaled prototype ITER NBI source at the BATMAN testbed were investigated by means of two beam diagnostics: Beam Emission Spectroscopy (BES) and a calorimeter. Two modifications to the prototype were applied. The first was the installation of a second Cs oven at the bottom part of the backplate in addition to the standard one at the upper part of the backplate varying the Cs evaporation asymmetry inside the source. The second consisted in the replacement of the cylindrical driver with a larger racetrack-shaped RF driver and placing a single Cs oven in a central position at the backplate of the driver. The resulting beam characteristics are discussed and compared with those obtained with the previous source design. The position of the Cs oven and the different driver size and geometry appear not to influence the beam profile and the beam deflection for a well-conditioned source.

Turbulent transport stabilization by ICRH minority fast ions in low rotating JET ILW L-mode plasmas

NASA Astrophysics Data System (ADS)

Bonanomi, N.; Mantica, P.; Di Siena, A.; Delabie, E.; Giroud, C.; Johnson, T.; Lerche, E.; Menmuir, S.; Tsalas, M.; Van Eester, D.; Contributors, JET

2018-05-01

The first experimental demonstration that fast ion induced stabilization of thermal turbulent transport takes place also at low values of plasma toroidal rotation has been obtained in JET ILW (ITER-like wall) L-mode plasmas with high (3He)-D ICRH (ion cyclotron resonance heating) power. A reduction of the gyro-Bohm normalized ion heat flux and higher values of the normalized ion temperature gradient have been observed at high ICRH power and low NBI (neutral beam injection) power and plasma rotation. Gyrokinetic simulations indicate that ITG (ion temperature gradient) turbulence stabilization induced by the presence of high-energetic 3He ions is the key mechanism in order to explain the experimental observations. Two main mechanisms have been identified to be responsible for the turbulence stabilization: a linear electrostatic wave-fast particle resonance mechanism and a nonlinear electromagnetic mechanism. The dependence of the stabilization on the 3He distribution function has also been studied.

Initial operation of the Lockheed Martin T4B experiment

NASA Astrophysics Data System (ADS)

Garrett, M. L.; Blinzer, A.; Ebersohn, F.; Gucker, S.; Heinrich, J.; Lohff, C.; McGuire, T.; Montecalvo, N.; Raymond, A.; Rhoads, J.; Ross, P.; Sommers, B.; Strandberg, E.; Sullivan, R.; Walker, J.

2017-10-01

The T4B experiment is a linear, encapsulated ring cusp confinement device, designed to develop a physics and technology basis for a follow-on high beta (β 1) machine. The experiment consists of 13 magnetic field coils (11 external, 2 internal), to produce a series of on-axis field nulls surrounded by modest magnetic fields of up to 0.3 T. The primary plasma source used on T4B is a lanthanum hexaboride (LaB6) cathode, capable of coupling over 100 kW into the plasma. Initial testing focused on commissioning of components and integration of diagnostics. Diagnostics include both long and short wavelength interferometry, bolometry, visible and X-ray spectroscopy, Langmuir and B-dot probes, Thomson scattering, flux loops, and fast camera imagery. Low energy discharges were used to begin validation of physics models and simulation efforts. Following the initial machine check-out, neutral beam injection (NBI) was integrated onto the device. Detailed results will be presented. 2017 Lockheed Martin Corporation. All Rights Reserved.

Initial applications of the non-Maxwellian extension of the full-wave TORIC v.5 code in the mid/high harmonic and minority heating regimes

NASA Astrophysics Data System (ADS)

Bertelli, N.; Valeo, E. J.; Phillips, C. K.

2015-11-01

A non Maxwellian extension of the full wave TORIC v.5 code in the mid/high harmonic and minority heating regimes has been revisited. In both regimes the treatment of the non-Maxwellian ions is needed in order to improve the analysis of combined fast wave (FW) and neutral beam injection (NBI) heated discharges in the current fusion devices. Additionally, this extension is also needed in time-dependent analysis where the combined heating experiments are generally considered. Initial numerical cases with thermal ions and with a non-Maxwellian ions are presented for both regimes. The simulations are then compared with results from the AORSA code, which has already been extended to include non-Maxwellian ions. First attempts to apply this extension in a self-consistent way with the NUBEAM module, which is included in the TRANSP code, are also discussed. Work supported by US DOE Contracts # DE-FC02-01ER54648 and DE-AC02-09CH11466.

Impurity behavior during ion-Bernstein wave heating in PBX-M

NASA Astrophysics Data System (ADS)

Isler, R. C.; Post-Zwicker, A. P.; Paul, S. F.; Tighe, W.; Ono, M.; Leblanc, B. P.; Bell, R.; Kugel, H. W.; Kaita, R.

1994-07-01

Ion-Bernstein-wave heating (IBWH) has been tested in several tokamaks. In some cases the results have been quite positive, producing temperature increases and also improving both energy and particle confinement times, whereas in others, no distinctive changes were observed. Most recently, IBWH has been utilized in the Princeton Beta Experiment-Modified (PBX-M) where the long-range goal is the achievement of operation in the second stable region by current and pressure profile control. Investigations have been performed in this machine using IBWH as the sole source of auxiliary power or using IBWH in conjunction with neutral-beam injection (NBI) or with lower-hybrid current drive (LHCD). Impurity studies seem particularly important for IBWH since not only have influxes often been observed to increase, but the global impurity confinement time has also been shown to lengthen as the confinement of the working gas improved. The authors present here a set of characteristic experimental results regarding the impurity behavior in PBX-M; in general, these are consonant with previous observations in other tokamaks.

Study of ion-gyroscale fluctuations in low-density L-mode plasmas heated by NBI on KSTAR

NASA Astrophysics Data System (ADS)

Lee, W.; Ko, S. H.; Leem, J.; Yun, G. S.; Park, H. K.; Wang, W. X.; Budny, R. V.; Kim, K. W.; Luhmann, N. C., Jr.; The KSTAR Team

2018-04-01

Broadband density fluctuations with peak frequency ranging from 150 to 400 kHz were measured using a multichannel microwave imaging reflectometer in core region of the low-density L-mode plasmas heated by neutral beam injection on KSTAR. These fluctuations have been studied by comparing the dominant mode scales estimated from the measurement with those predicted from linear gyrokinetic simulation. The measured poloidal wavenumbers are qualitatively comparable to those of the ‘fastest growing modes’ from simulations, whereas they are larger than those of the ‘transport-dominant modes’ by about a factor of three. The agreement on wavenumbers between the measurement and linear simulation (for the fastest growing modes) is probably due to sufficiently weak E × B flow shear compared to the maximum linear growth rate. Meanwhile, the transport-dominant modes seem to be related to the fluctuations in lower frequencies (˜80-150 kHz) observed in some of the measurement.

Estimation of Electron Bernstein Emission in the TJ-II Stellarator

NASA Astrophysics Data System (ADS)

García-Rega\\ Na, J. M.; Cappa, A.; Castejón, F.; Tereshchenko, M.

2009-05-01

In order to study experimentally the viability of first harmonic EBW heating in the TJ-II stellarator by means of the O-X-B tecnique [1], an EBE diagnostic was recently installed [2]. In the present work a theoretical estimation of the EBW radiation in the TJ-II plasmas have been carried out making use of the ray tracing code TRUBA [3]. The line of sight of the EBE diagnostic may be modified using an internal movable mirror and therefore, for comparison with the experimental results, the theoretical O-X-B emission window has been determined. Experimental density and temperature profiles obtained in NBI discharges are considered in the simulations.References:[1] F. Castejon et al, Nucl. Fusion 48, 075011 (2008).[2] J. Caughman et al, Proc. 15th Joint Workshop on ECE and ECRH, Yosemite, USA (2008).[3] M. A. Tereshchenko et. al, Proc. 30th EPS Conference on Contr. Fusion and Plasma Phys., 27A, P-1.18 (2003).

Analysis and Design of ITER 1 MV Core Snubber

NASA Astrophysics Data System (ADS)

Wang, Haitian; Li, Ge

2012-11-01

The core snubber, as a passive protection device, can suppress arc current and absorb stored energy in stray capacitance during the electrical breakdown in accelerating electrodes of ITER NBI. In order to design the core snubber of ITER, the control parameters of the arc peak current have been firstly analyzed by the Fink-Baker-Owren (FBO) method, which are used for designing the DIIID 100 kV snubber. The B-H curve can be derived from the measured voltage and current waveforms, and the hysteresis loss of the core snubber can be derived using the revised parallelogram method. The core snubber can be a simplified representation as an equivalent parallel resistance and inductance, which has been neglected by the FBO method. A simulation code including the parallel equivalent resistance and inductance has been set up. The simulation and experiments result in dramatically large arc shorting currents due to the parallel inductance effect. The case shows that the core snubber utilizing the FBO method gives more compact design.

Transoral Laser Microsurgery in Early Glottic Lesions.

PubMed

Sjögren, E V

2017-01-01

To give an overview of the evolvement of transoral laser microsurgery (TLM) in the treatment of early glottic carcinoma and highlight the contribution of recent literature. The indications and limits of TLM have been well specified. Effects on swallowing have been well documented. Introduction of narrow-band imaging (NBI) and diffusion-weighted magnetic resonance has been shown of additional value for outcome. The first reports on transoral robotic surgery show that it may be of added value in the future. TLM for early glottic carcinoma (Tis-T2) has very good oncological outcomes with indications of higher larynx preservation in TLM than that in radiotherapy. The anterior commissure is a risk factor if involved in the cranio-caudal plane, and reduced vocal fold mobility is a risk factor when this is due to arytenoid involvement. The best voice results are achieved when the anterior commissure can be left intact along with part of the vocal fold muscle although even in larger resections, patient self-reported voice handicap is still limited.

First experiments with the negative ion source NIO1.

PubMed

Cavenago, M; Serianni, G; De Muri, M; Agostinetti, P; Antoni, V; Baltador, C; Barbisan, M; Baseggio, L; Bigi, M; Cervaro, V; Degli Agostini, F; Fagotti, E; Kulevoy, T; Ippolito, N; Laterza, B; Minarello, A; Maniero, M; Pasqualotto, R; Petrenko, S; Poggi, M; Ravarotto, D; Recchia, M; Sartori, E; Sattin, M; Sonato, P; Taccogna, F; Variale, V; Veltri, P; Zaniol, B; Zanotto, L; Zucchetti, S

2016-02-01

Neutral Beam Injectors (NBIs), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact radio frequency (rf) ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, was installed at Consorzio RFX, including a high voltage deck and an X-ray shield, to provide a test bench for source optimizations for activities in support to the ITER NBI test facility. NIO1 status and plasma experiments both with air and with hydrogen as filling gas are described. Transition from a weak plasma to an inductively coupled plasma is clearly evident for the former gas and may be triggered by rising the rf power (over 0.5 kW) at low pressure (equal or below 2 Pa). Transition in hydrogen plasma requires more rf power (over 1.5 kW).

Design and Control of Hydronic Radiant Cooling Systems

NASA Astrophysics Data System (ADS)

Feng, Jingjuan

Improving energy efficiency in the Heating Ventilation and Air conditioning (HVAC) systems in buildings is critical to achieve the energy reduction in the building sector, which consumes 41% of all primary energy produced in the United States, and was responsible for nearly half of U.S. CO2 emissions. Based on a report by the New Building Institute (NBI), when HVAC systems are used, about half of the zero net energy (ZNE) buildings report using a radiant cooling/heating system, often in conjunction with ground source heat pumps. Radiant systems differ from air systems in the main heat transfer mechanism used to remove heat from a space, and in their control characteristics when responding to changes in control signals and room thermal conditions. This dissertation investigates three related design and control topics: cooling load calculations, cooling capacity estimation, and control for the heavyweight radiant systems. These three issues are fundamental to the development of accurate design/modeling tools, relevant performance testing methods, and ultimately the realization of the potential energy benefits of radiant systems. Cooling load calculations are a crucial step in designing any HVAC system. In the current standards, cooling load is defined and calculated independent of HVAC system type. In this dissertation, I present research evidence that sensible zone cooling loads for radiant systems are different from cooling loads for traditional air systems. Energy simulations, in EnergyPlus, and laboratory experiments were conducted to investigate the heat transfer dynamics in spaces conditioned by radiant and air systems. The results show that the magnitude of the cooling load difference between the two systems ranges from 7-85%, and radiant systems remove heat faster than air systems. For the experimental tested conditions, 75-82% of total heat gain was removed by radiant system during the period when the heater (simulating the heat gain) was on, while for air system, 61-63% were removed. From a heat transfer perspective, the differences are mainly because the chilled surfaces directly remove part of the radiant heat gains from a zone, thereby bypassing the time-delay effect caused by the interaction of radiant heat gain with non-active thermal mass in air systems. The major conclusions based on these findings are: 1) there are important limitations in the definition of cooling load for a mixing air system described in Chapter 18 of ASHRAE Handbook of Fundamentals when applied to radiant systems; 2) due to the obvious mismatch between how radiant heat transfer is handled in traditional cooling load calculation methods compared to its central role in radiant cooling systems, this dissertation provides improvements for the current cooling load calculation method based on the Heat Balance procedure. The Radiant Time Series method is not appropriate for radiant system applications. The findings also directly apply to the selection of space heat transfer modeling algorithms that are part of all energy modeling software. Cooling capacity estimation is another critical step in a design project. The above mentioned findings and a review of the existing methods indicates that current radiant system cooling capacity estimation methods fail to take into account incident shortwave radiation generated by solar and lighting in the calculation process. This causes a significant underestimation (up to 150% for some instances) of floor cooling capacity when solar load is dominant. Building performance simulations were conducted to verify this hypothesis and quantify the impacts of solar for different design scenarios. A new simplified method was proposed to improve the predictability of the method described in ISO 11855 when solar radiation is present. The dissertation also compares the energy and comfort benefits of the model-based predictive control (MPC) method with a fine-tuned heuristic control method when applied to a heavyweight embedded surface system. A first order dynamic model of a radiant slab system was developed for implementation in model predictive controllers. A calibrated EnergyPlus model of a typical office building in California was used as a testbed for the comparison. The results indicated that MPC is able to reduce the cooling tower energy consumption by 55% and pumping power consumption by 26%, while maintaining equivalent or even better thermal comfort conditions. In summary, the dissertation work has: (1) provided clear evidence that the fundamental heat transfer mechanisms differ between radiant and air systems. These findings have important implications for the development of accurate and reliable design and energy simulation tools; (2) developed practical design methods and guidance to aid practicing engineers who are designing radiant systems; and (3) outlined future research and design tools need to advance the state-of-knowledge and design and operating guidelines for radiant systems.

Experimental and numerical investigation of HyperVapotron heat transfer

NASA Astrophysics Data System (ADS)

Wang, Weihua; Deng, Haifei; Huang, Shenghong; Chu, Delin; Yang, Bin; Mei, Luoqin; Pan, Baoguo

2014-12-01

The divertor first wall and neutral beam injection (NBI) components of tokamak devices require high heat flux removal up to 20-30 MW m-2 for future fusion reactors. The water cooled HyperVapotron (HV) structure, which relies on internal grooves or fins and boiling heat transfer to maximize the heat transfer capability, is the most promising candidate. The HV devices, that are able to transfer large amounts of heat (1-20 MW m-2) efficiently, have therefore been developed specifically for this application. Until recently, there have been few attempts to observe the detailed bubble characteristics and vortex evolvement of coolant flowing inside their various parts and understand of the internal two-phase complex heat transfer mechanism behind the vapotron effect. This research builds the experimental facilities of HyperVapotron Loop-I (HVL-I) and Pressure Water HyperVapotron Loop-II (PWHL-II) to implement the subcooled boiling principle experiment in terms of typical flow parameters, geometrical parameters of test section and surface heat flux, which are similar to those of the ITER-like first wall and NBI components (EAST and MAST). The multiphase flow and heat transfer phenomena on the surface of grooves and triangular fins when the subcooled water flowed through were observed and measured with the planar laser induced fluorescence (PLIF) and high-speed photography (HSP) techniques. Particle image velocimetry (PIV) was selected to reveal vortex formation, the flow structure that promotes the vapotron effect during subcooled boiling. The coolant flow data for contributing to the understanding of the vapotron phenomenon and the assessment of how the design and operational conditions that might affect the thermal performance of the devices were collected and analysed. The subcooled flow boiling model and methods of HV heat transfer adopted in the considered computational fluid dynamics (CFD) code were evaluated by comparing the calculated wall temperatures with the experimentally measured values. It was discovered that the bubble and vortex characteristics in the HV are clearly heavily dependent on the internal geometry, flow conditions and input heat flux. The evaporation latent heat is the primary heat transfer mechanism of HV flow under the condition of high heat flux, and the heat transfer through convection is very limited. The percentage of wall heat flux going into vapour production is almost 70%. These relationships between the flow phenomena and thermal performance of the HV device are essential to study the mechanisms for the flow structure alterations for design optimization and improvements of the ITER-like devices' water cooling structure and plasma facing components for future fusion reactors.

Measuring pasture degradation on the Qinghai-Tibet Plateau using hyperspectral dissimilarities and indices

NASA Astrophysics Data System (ADS)

Meyer, Hanna; Lehnert, Lukas W.; Wang, Yun; Reudenbach, Christoph; Bendix, Jörg

2013-10-01

Despite that relevance of pasture degradation on the Qinghai-Tibet Plateau (QTP) is widely postulated, its extent is still unknown. However, livestock grazing is widely accepted as a major factor. This study investigated spectral differences of vegetation patterns along gradients of grazing intensities using plot-based hyperspectral measurements. The measurements were used to define spectral indicators for pasture degradation, which were applied to map asserted proxies for degradation from satellite images. For this purpose, hyperspectral measurements were taken at 11 sites on the north-eastern QTP using a transect design from heavy grazing and therefore asserted degradation near the settlement to less degradation with increasing distance. Potential spectral indicators for degradation were derived from the spectra by calculating the size of continuum removed absorption features and narrow-band indices (NBI). They were compared between degraded and less degraded plots. Linear regressions between proxies and each of the potential spectral indicators were calculated to assess its predictive power. The findings were transferred to larger scales by applying the indicators on two WorldView-2 (WV-2) scenes. Spectral differences between degraded and less degraded plots were obvious regarding a wide range of tested indicators. Several NBIs were considered as good indicators for vegetation cover and species numbers. WV-2 images could be successfully classified into vegetation cover whilst the estimation of species numbers was afflicted with uncertainties. The results demonstrate the potential to estimate degradation proxies using spectrometer measurements and satellite data. Applying these techniques will contribute to a better estimation of spatial degradation patterns on the QTP.

A review of bioinformatics platforms for comparative genomics. Recent developments of the EDGAR 2.0 platform and its utility for taxonomic and phylogenetic studies.

PubMed

Yu, J; Blom, J; Glaeser, S P; Jaenicke, S; Juhre, T; Rupp, O; Schwengers, O; Spänig, S; Goesmann, A

2017-11-10

The rapid development of next generation sequencing technology has greatly increased the amount of available microbial genomes. As a result of this development, there is a rising demand for fast and automated approaches in analyzing these genomes in a comparative way. Whole genome sequencing also bears a huge potential for obtaining a higher resolution in phylogenetic and taxonomic classification. During the last decade, several software tools and platforms have been developed in the field of comparative genomics. In this manuscript, we review the most commonly used platforms and approaches for ortholog group analyses with a focus on their potential for phylogenetic and taxonomic research. Furthermore, we describe the latest improvements of the EDGAR platform for comparative genome analyses and present recent examples of its application for the phylogenomic analysis of different taxa. Finally, we illustrate the role of the EDGAR platform as part of the BiGi Center for Microbial Bioinformatics within the German network on Bioinformatics Infrastructure (de.NBI). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Measurements and modelling of fast-ion redistribution due to resonant MHD instabilities in MAST

NASA Astrophysics Data System (ADS)

Jones, O. M.; Cecconello, M.; McClements, K. G.; Klimek, I.; Akers, R. J.; Boeglin, W. U.; Keeling, D. L.; Meakins, A. J.; Perez, R. V.; Sharapov, S. E.; Turnyanskiy, M.; the MAST Team

2015-12-01

The results of a comprehensive investigation into the effects of toroidicity-induced Alfvén eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due to frequency-chirping TAE in the range 50 kHz-100 kHz and frequency-chirping energetic particle modes known as fishbones in the range 20 kHz-50 kHz, is observed. TAE and fishbones are also observed to cause losses of fast ions from the plasma. The spatial and temporal evolution of the fast-ion distribution is determined using a fission chamber, a radially-scanning collimated neutron flux monitor, a fast-ion deuterium alpha spectrometer and a charged fusion product detector. Modelling using the global transport analysis code Transp, with ad hoc anomalous diffusion and fishbone loss models introduced, reproduces the coarsest features of the affected fast-ion distribution in the presence of energetic particle-driven modes. The spectrally and spatially resolved measurements show, however, that these models do not fully capture the effects of chirping modes on the fast-ion distribution.

Suppression of Alfvénic modes with off-axis NBI

NASA Astrophysics Data System (ADS)

Fredrickson, Eric; Bell, R.; Diallo, A.; Leblanc, B.; Podesta, M.; Levinton, F.; Yuh, H.; Liu, D.

2016-10-01

GAE are seen on NSTX-U in the frequency range from 1 to 3 MHz with injection of the more perpendicular, NSTX neutral beam sources. A new result is that injection of any of the new, more tangential, neutral beam sources with tangency radii larger than the magnetic axis suppress this GAE activity. Simulations of beam deposition and slowing down with the TRANSP code indicate that these new sources deposit fast ions with 0.9

Overview of the new capabilities of TORIC-v6 and comparison with TORIC-v5

NASA Astrophysics Data System (ADS)

Bilato, R.; Brambilla, M.; Bertelli, N.

2016-10-01

Since its release, version 5 (v5) of the full-wave TORIC code, characterized by an optimized parallelized solver for its routinely use in TRANSP package, has been ameliorated in many technical issues, e.g. the plasma-vacuum transition and the full-spectrum antenna modeling. For the WPCD-benchmark cases a good agreement between the new version, v6, and v5 is found. The major improvement, however, has been done in interfacing TORIC-v6 with the Fokker-Planck SSFPQL solver to account for the back-reaction of ICRF and NBI heating on the wave propagation and absorption. Special algorithms have been developed for SSFPQL for the numerical precision at high pitch-angle resolution and to evaluate the generalized dispersion function directly from the numerical solution. Care has been spent in automatizing the non-linear loop between TORIC-v6 and SSFPQL. In v6 the description of wave absorption at high-harmonics has been revised and applied to DEMO. For high-harmonic regimes there is an ongoing activity on the comparison with AORSA.

Trapping Experiments on a Trichlorosilanide Anion: a Key Intermediate of Halogenosilane Chemistry.

PubMed

Teichmann, Julian; Bursch, Markus; Köstler, Benedikt; Bolte, Michael; Lerner, Hans-Wolfram; Grimme, Stefan; Wagner, Matthias

2017-08-07

Treatment of Si 2 Cl 6 with [Et 4 N][BCl 4 ] in CH 2 Cl 2 furnished the known products of a chloride-induced disproportionation reaction of the disilane, such as SiCl 4 , [Si(SiCl 3 ) 3 ] - , and [Si 6 Cl 12 ·2Cl] 2- . No Si-B-bonded products were detectable. In contrast, the addition of Si 2 Cl 6 to [Et 4 N][BI 3 Cl] afforded the Si-B adduct [Et 4 N][I 3 SiBI 3 ]. Thus, a quantitative Cl/I exchange at the silicon atom accompanies the trihalogenosilanide formation. [Et 4 N][I 3 SiBI 3 ] was also accessible from a mixture of Si 2 I 6 , [Et 4 N]I, and BI 3 . According to X-ray crystallography, the anion [I 3 SiBI 3 ] - adopts a staggered conformation with an Si-B bond length of 1.977(6) Å. Quantum-chemical calculations revealed a polar covalent Si-B bond with significant contributions from intramolecular I···I dispersion interactions.

High Harmonic Fast Wave Damping on an Ion Beam: NSTX and DIII-D Regimes Compared

NASA Astrophysics Data System (ADS)

Pinsker, R. I.; Choi, C. C.; Petty, C. C.; Porkolab, M.; Wilson, J. R.; Murakami, M.; Harvey, R. W.

2004-11-01

Both NSTX and DIII-D use the combination of fast Alfven waves (FW) and neutral beam injection (NBI) for central electron heating and current drive. Damping of the fast wave on the beam ions at moderate to high harmonics (4th--20th) of the beam ion cyclotron frequency represents a loss process. In DIII-D current drive experiments at low density in which 4th and 8th harmonics were compared, damping at the 8th harmonic damping was much weaker than at the 4th [1]. However, recent simulations have predicted that in higher density and higher beam power regimes (of interest to the Advanced Tokamak program) the beam ion absorption will transition to the unmagnetized ion regime, where the damping is significant and essentially independent of harmonic number. In the present work, the transition from magnetized to unmagnetized ion regimes for the NSTX and DIII-D HHFW experiments is studied theoretically, with a combination of simple semi-analytic models and numerical models. \\vspace0.25 em [1] C.C. Petty, et al., Plasma Phys. and Contr. Fusion 43, 1747 (2001).

Initial experiments with a versatile multi-aperture negative-ion source and related improvements

NASA Astrophysics Data System (ADS)

Cavenago, M.

2016-03-01

A relatively compact ion source, named NIO1 (Negative-Ion Optimization 1), with 9 beam apertures for H- extraction is under commissioning, in collaboration between Consorzio RFX and INFN, to provide a test bench for source optimizations, for innovations, and for simulation code validations in support of Neutral Beam Injectors (NBI) optimization. NIO1 installation includes a 60kV high-voltage deck, power supplies for a 130mA ion nominal current, an X-ray shield, and beam diagnostics. Plasma is heated with a tunable 2MHz radiofrequency (rf) generator. Physical aspects of source operation and rf-plasma coupling are discussed. NIO1 tuning procedures and plasma experiments both with air and with hydrogen as filling gas are described, up to a 1.7kW rf power. Transitions to inductively coupled plasma are reported in the case of air (for a rf power of about 0.5kW and a gas pressure below 2Pa), discussing their robust signature in optical emission, and briefly summarized for hydrogen, where more than 1kW rf power is needed.

Profile measurements of the electron temperature on the ASDEX Upgrade, COMPASS, and ISTTOK tokamak using Thomson scattering, triple, and ball-pen probes

NASA Astrophysics Data System (ADS)

Adamek, J.; Müller, H. W.; Silva, C.; Schrittwieser, R.; Ionita, C.; Mehlmann, F.; Costea, S.; Horacek, J.; Kurzan, B.; Bilkova, P.; Böhm, P.; Aftanas, M.; Vondracek, P.; Stöckel, J.; Panek, R.; Fernandes, H.; Figueiredo, H.

2016-04-01

The ball-pen probe (BPP) technique is used successfully to make profile measurements of the electron temperature on the ASDEX Upgrade (Axially Symmetric Divertor Experiment), COMPASS (COMPact ASSembly), and ISTTOK (Instituto Superior Tecnico TOKamak) tokamak. The electron temperature is provided by a combination of the BPP potential (ΦBPP) and the floating potential (Vfl) of the Langmuir probe (LP), which is compared with the Thomson scattering diagnostic on ASDEX Upgrade and COMPASS. Excellent agreement between the two diagnostics is obtained for circular and diverted plasmas and different heating mechanisms (Ohmic, NBI, ECRH) in deuterium discharges with the same formula Te = (ΦBPP - Vfl)/2.2. The comparative measurements of the electron temperature using BPP/LP and triple probe (TP) techniques on the ISTTOK tokamak show good agreement of averaged values only inside the separatrix. It was also found that the TP provides the electron temperature with significantly higher standard deviation than BPP/LP. However, the resulting values of both techniques are well in the phase with the maximum of cross-correlation function being 0.8.

Profile measurements of the electron temperature on the ASDEX Upgrade, COMPASS, and ISTTOK tokamak using Thomson scattering, triple, and ball-pen probes.

PubMed

Adamek, J; Müller, H W; Silva, C; Schrittwieser, R; Ionita, C; Mehlmann, F; Costea, S; Horacek, J; Kurzan, B; Bilkova, P; Böhm, P; Aftanas, M; Vondracek, P; Stöckel, J; Panek, R; Fernandes, H; Figueiredo, H

2016-04-01

The ball-pen probe (BPP) technique is used successfully to make profile measurements of the electron temperature on the ASDEX Upgrade (Axially Symmetric Divertor Experiment), COMPASS (COMPact ASSembly), and ISTTOK (Instituto Superior Tecnico TOKamak) tokamak. The electron temperature is provided by a combination of the BPP potential (ΦBPP) and the floating potential (Vfl) of the Langmuir probe (LP), which is compared with the Thomson scattering diagnostic on ASDEX Upgrade and COMPASS. Excellent agreement between the two diagnostics is obtained for circular and diverted plasmas and different heating mechanisms (Ohmic, NBI, ECRH) in deuterium discharges with the same formula Te = (ΦBPP - Vfl)/2.2. The comparative measurements of the electron temperature using BPP/LP and triple probe (TP) techniques on the ISTTOK tokamak show good agreement of averaged values only inside the separatrix. It was also found that the TP provides the electron temperature with significantly higher standard deviation than BPP/LP. However, the resulting values of both techniques are well in the phase with the maximum of cross-correlation function being 0.8.

Locked-mode avoidance and recovery without external momentum input

NASA Astrophysics Data System (ADS)

Delgado-Aparicio, L.; Gates, D. A.; Wolfe, S.; Rice, J. E.; Gao, C.; Wukitch, S.; Greenwald, M.; Hughes, J.; Marmar, E.; Scott, S.

2014-10-01

Error-field-induced locked-modes (LMs) have been studied in C-Mod at ITER toroidal fields without NBI fueling and momentum input. The use of ICRH heating in synch with the error-field ramp-up resulted in a successful delay of the mode-onset when PICRH > 1 MW and a transition into H-mode when PICRH > 2 MW. The recovery experiments consisted in applying ICRH power during the LM non-rotating phase successfully unlocking the core plasma. The ``induced'' toroidal rotation was in the counter-current direction, restoring the direction and magnitude of the toroidal flow before the LM formation, but contrary to the expected Rice-scaling in the co-current direction. However, the LM occurs near the LOC/SOC transition where rotation reversals are commonly observed. Once PICRH is turned off, the core plasma ``locks'' at later times depending on the evolution of ne and Vt. This work was performed under US DoE contracts including DE-FC02-99ER54512 and others at MIT and DE-AC02-09CH11466 at PPPL.

Locked-mode avoidance and recovery without momentum input

NASA Astrophysics Data System (ADS)

Delgado-Aparicio, L.; Rice, J. E.; Wolfe, S.; Cziegler, I.; Gao, C.; Granetz, R.; Wukitch, S.; Terry, J.; Greenwald, M.; Sugiyama, L.; Hubbard, A.; Hugges, J.; Marmar, E.; Phillips, P.; Rowan, W.

2015-11-01

Error-field-induced locked-modes (LMs) have been studied in Alcator C-Mod at ITER-Bϕ, without NBI fueling and momentum input. Delay of the mode-onset and locked-mode recovery has been successfully obtained without external momentum input using Ion Cyclotron Resonance Heating (ICRH). The use of external heating in-sync with the error-field ramp-up resulted in a successful delay of the mode-onset when PICRH > 1 MW, which demonstrates the existence of a power threshold to ``unlock'' the mode; in the presence of an error field the L-mode discharge can transition into H-mode only when PICRH > 2 MW and at high densities, avoiding also the density pump-out. The effects of ion heating observed on unlocking the core plasma may be due to ICRH induced flows in the plasma boundary, or modifications of plasma profiles that changed the underlying turbulence. This work was performed under US DoE contracts including DE-FC02-99ER54512 and others at MIT, DE-FG03-96ER-54373 at University of Texas at Austin, and DE-AC02-09CH11466 at PPPL.

Final Technical Report for SBIR entitled Four-Dimensional Finite-Orbit-Width Fokker-Planck Code with Sources, for Neoclassical/Anomalous Transport Simulation of Ion and Electron Distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, R. W.; Petrov, Yu. V.

2013-12-03

Within the US Department of Energy/Office of Fusion Energy magnetic fusion research program, there is an important whole-plasma-modeling need for a radio-frequency/neutral-beam-injection (RF/NBI) transport-oriented finite-difference Fokker-Planck (FP) code with combined capabilities for 4D (2R2V) geometry near the fusion plasma periphery, and computationally less demanding 3D (1R2V) bounce-averaged capabilities for plasma in the core of fusion devices. Demonstration of proof-of-principle achievement of this goal has been carried out in research carried out under Phase I of the SBIR award. Two DOE-sponsored codes, the CQL3D bounce-average Fokker-Planck code in which CompX has specialized, and the COGENT 4D, plasma edge-oriented Fokker-Planck code whichmore » has been constructed by Lawrence Livermore National Laboratory and Lawrence Berkeley Laboratory scientists, where coupled. Coupling was achieved by using CQL3D calculated velocity distributions including an energetic tail resulting from NBI, as boundary conditions for the COGENT code over the two-dimensional velocity space on a spatial interface (flux) surface at a given radius near the plasma periphery. The finite-orbit-width fast ions from the CQL3D distributions penetrated into the peripheral plasma modeled by the COGENT code. This combined code demonstrates the feasibility of the proposed 3D/4D code. By combining these codes, the greatest computational efficiency is achieved subject to present modeling needs in toroidally symmetric magnetic fusion devices. The more efficient 3D code can be used in its regions of applicability, coupled to the more computationally demanding 4D code in higher collisionality edge plasma regions where that extended capability is necessary for accurate representation of the plasma. More efficient code leads to greater use and utility of the model. An ancillary aim of the project is to make the combined 3D/4D code user friendly. Achievement of full-coupling of these two Fokker-Planck codes will advance computational modeling of plasma devices important to the USDOE magnetic fusion energy program, in particular the DIII-D tokamak at General Atomics, San Diego, the NSTX spherical tokamak at Princeton, New Jersey, and the MST reversed-field-pinch Madison, Wisconsin. The validation studies of the code against the experiments will improve understanding of physics important for magnetic fusion, and will increase our design capabilities for achieving the goals of the International Tokamak Experimental Reactor (ITER) project in which the US is a participant and which seeks to demonstrate at least a factor of five in fusion power production divided by input power.« less

Long-term Evolution of the Aerosol Debris Cloud Produced by the 2009 Impact of an Object with Jupiter

NASA Astrophysics Data System (ADS)

Sanchez-Lavega, Agustin; Orton, G. S.; Hueso, R.; Pérez-Hoyos, S.; Fletcher, L. N.; Garcia-Melendo, E.; Gomez, J. M.; de Pater, I.; Wong, M.; Hammel, H. B.; Yanamandra-Fisher, P.; Simon-Miller, M.; Barrado-Izagirre, N.; Marchis, F.; Mousis, O.; Ortiz, J. L.; Garcia, J.; Cecconi, M.; Clarke, J. T.; Noll, K.; Pedraz, S.; Wesley, A.; McConnel, N.; Kalas, P.; Graham, J.; McKenzie, L.; Reddy, V.; Golisch, W.; Griep, D.; Sears, P.; International Outer PLanet Watch (IOPW)

2010-10-01

We report the evolution of the cloud of aerosols produced in the atmosphere of Jupiter by the impact of an object in 19 July 2009 (Sánchez-Lavega et al., Astrophys. J. Lett, Vol. 715, L155. 2010). This study is based on images obtained with a battery of ground-based telescopes and the Hubble Space Telescope in the visible and in the deep near infrared absorption bands at 2.1-2.3 microns from the impact date to 31 December 2009. The impact cloud expanded zonally from 5000 km (July 19) to 225,000 km (about 180 deg in longitude by 29 October) and it was meridionally localized within a latitude band from -53.5 deg to -61.5 deg. During the first two months it showed a heterogeneous structure with embedded spots of a size of 500 - 1000 km. The cloud was mainly dispersed in longitude by the dominant zonal winds and their meridional shear and, during the initial stages, by the action of local motions perhaps originated by the thermal perturbation produced at the impact site. The tracking of individual spots within the impact cloud showed that the winds increase their eastward velocity with altitude above the tropopause by 5-10 m/s. We found evidence of discrete localized meridional motions in the equatorward direction with speeds of 1 - 2 m/s. Measurements of the cloud reflectivity evolution during the whole period showed that it followed an exponential decrease with a characteristic time of 15 days, shorter than the 45 - 200 days sedimentation time for the small aerosol particles in the stratosphere. A radiative transfer model of the cloud optical depth coupled to an advection model of the cloud dispersion by the wind shears, reproduces this behavior. Acknowledgements: ASL, RH, SPH, NBI are supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

Conceptual design of the EU DEMO EC-system: main developments and R&D achievements

NASA Astrophysics Data System (ADS)

Granucci, G.; Aiello, G.; Alberti, S.; Avramidis, K. A.; Braunmüller, F.; Bruschi, A.; Chelis, J.; Franck, J.; Figini, L.; Gantenbein, G.; Garavaglia, S.; Grossetti, G.; Illy, S.; Ioannidis, Z.; Jelonnek, J.; Kalaria, P.; Latsas, G.; Moro, A.; Pagonakis, I. Gr.; Peponis, D.; Poli, E.; Rispoli, N.; Rzesnicki, T.; Scherer, T.; Strauss, D.; Thumm, M.; Tigelis, I.; Tsironis, C.; Wu, C.; Franke, T.; Tran, M. Q.

2017-11-01

For the development of a DEMOnstration Fusion Power Plant the design of auxiliary heating systems is a key activity in order to achieve controlled burning plasma. The present heating mix considers electron cyclotron resonance heating (ECRH), neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH) with a target power to the plasma of about 50 MW for each system. The main tasks assigned to the EC system are plasma breakdown and assisted start-up, heating to L-H transition and plasma current ramp up to burn, MHD stability control and assistance in plasma current ramp down. The consequent requirements are used for the conceptual design of the EC system, from the RF source to the launcher, with an extensive R&D program focused on relevant technologies to be developed. Gyrotron: the R&D and Advanced Developments on EC RF sources are targeting for gyrotrons operating at 240 GHz, considered as optimum EC Current Drive frequency in case of higher magnetic field than for the 2015 EU DEMO1 baseline. Multi-purpose (multi-frequency) and frequency step-tunable gyrotrons are under investigation to increase the flexibility of the system. As main targets an output power of significantly above 1 MW (target: 2 MW) and a total efficiency higher than 60% are set. The principle feasibility at limits of a 236 GHz, conventional-cavity and, alternatively, of a 238 GHz coaxial-cavity gyrotron are under investigation together with the development of a synthetic diamond Brewster-angle window technology. Advanced developments are on-going in the field of multi-stage depressed collector technologies. Transmission line (TL): different TL options are under investigation and a preliminary study of an evacuated quasi-optical multiple-beam TL, considered for a hybrid solution, is presented and discussed in terms of layout, dimensions and theoretical losses. Launcher: remote steering antennas have been considered as a possible launcher solution especially under the constraints to avoid movable mirrors close to the plasma. With dedicated beam tracing calculations, the deposition locations coverage and the wave absorption efficiency have been investigated, considering a selection of frequencies, injection angles and launching points. An option for the EC system structure is proposed in clusters, in order to allow the necessary redundancy and flexibility to guarantee the required EC power in the different phases of the plasma pulse. Number and composition of the clusters are analysed to have high availability and therefore maximum reliability with a minimum number of components.

Bulk ion heating with ICRF waves in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mantsinen, M. J., E-mail: mervi.mantsinen@bsc.es; Barcelona Supercomputing Center, Barcelona; Bilato, R.

2015-12-10

Heating with ICRF waves is a well-established method on present-day tokamaks and one of the heating systems foreseen for ITER. However, further work is still needed to test and optimize its performance in fusion devices with metallic high-Z plasma facing components (PFCs) in preparation of ITER and DEMO operation. This is of particular importance for the bulk ion heating capabilities of ICRF waves. Efficient bulk ion heating with the standard ITER ICRF scheme, i.e. the second harmonic heating of tritium with or without {sup 3}He minority, was demonstrated in experiments carried out in deuterium-tritium plasmas on JET and TFTR andmore » is confirmed by ICRF modelling. This paper focuses on recent experiments with {sup 3}He minority heating for bulk ion heating on the ASDEX Upgrade (AUG) tokamak with ITER-relevant all-tungsten PFCs. An increase of 80% in the central ion temperature T{sub i} from 3 to 5.5 keV was achieved when 3 MW of ICRF power tuned to the central {sup 3}He ion cyclotron resonance was added to 4.5 MW of deuterium NBI. The radial gradient of the T{sub i} profile reached locally values up to about 50 keV/m and the normalized logarithmic ion temperature gradients R/LT{sub i} of about 20, which are unusually large for AUG plasmas. The large changes in the T{sub i} profiles were accompanied by significant changes in measured plasma toroidal rotation, plasma impurity profiles and MHD activity, which indicate concomitant changes in plasma properties with the application of ICRF waves. When the {sup 3}He concentration was increased above the optimum range for bulk ion heating, a weaker peaking of the ion temperature profile was observed, in line with theoretical expectations.« less

Steady state scenario development with elevated minimum safety factor on DIII-D

DOE PAGES

Holcomb, Christopher T.; Ferron, John R.; Luce, Timothy C.; ...

2014-08-15

On DIII-D, a high β scenario with minimum safety factor (q min) near 1.4 has been optimized with new tools and shown to be a favourable candidate for long pulse or steady state operation in future devices. Furthermore, the new capability to redirect up to 5 MW of neutral beam injection (NBI) from on- to off-axis improves the ability to sustain elevated q min with a less peaked pressure profile. The observed changes increase the ideal magnetohydrodynamics (MHD) n = 1 mode β N limit thus providing a path forward for increasing the noninductive current drive fraction by operating atmore » high β N. Quasi-stationary discharges free of tearing modes have been sustained at βN = 3.5 and β T = 3.6% for two current profile diffusion timescales (about 3 s) limited by neutral beam duration. The discharge performance has normalized fusion performance expected to give fusion gain Q ≈ 5 in a device the size of ITER. Analysis of the poloidal flux evolution and current drive balance show that the loop voltage profile is almost relaxed even with 25% of the current driven inductively, and q min remains elevated near 1.4. Our observations increase confidence that the current profile will not evolve to one unstable to a tearing mode. In preliminary tests a divertor heat flux reduction technique based on producing a radiating mantle with neon injection appears compatible with this operating scenario. 0D model extrapolations suggest it may be possible to push this scenario up to 100% noninductive current drive by raising β N. Similar discharges with q min = 1.5–2 were susceptible to tearing modes and off-axis fishbones, and with q min > 2 lower normalized global energy confinement time is observed.« less

Tungsten: an option for divertor and main chamber plasma facing components in future fusion devices

NASA Astrophysics Data System (ADS)

Neu, R.; Dux, R.; Kallenbach, A.; Pütterich, T.; Balden, M.; Fuchs, J. C.; Herrmann, A.; Maggi, C. F.; O'Mullane, M.; Pugno, R.; Radivojevic, I.; Rohde, V.; Sips, A. C. C.; Suttrop, W.; Whiteford, A.; ASDEX Upgrade Team

2005-03-01

The tungsten programme in ASDEX Upgrade is pursued towards a full high-Z device. The spectroscopic diagnostic of W has been extended and refined and the cooling factor of W has been re-evaluated. The W coated surfaces now represent a fraction of 65% of all plasma facing components (24.8 m2). The only two major components that are not yet coated are the strikepoint region of the lower divertor as well as the limiters at the low field side. While extending the W surfaces, the W concentration and the discharge behaviour have changed gradually pointing to critical issues when operating with a W wall: anomalous transport in the plasma centre should not be too low, otherwise neoclassical accumulation can occur. One very successful remedy is the addition of central RF heating at the 20-30% level. Regimes with low ELM activity show increased impurity concentration over the whole plasma radius. These discharges can be cured by increasing the ELM frequency through pellet ELM pacemaking or by higher heating power. Moderate gas puffing also mitigates the impurity influx and penetration, however, at the expense of lower confinement. The erosion yield at the low field side guard limiter can be as high as 10-3 and fast particle losses from NBI were identified to contribute a significant part to the W sputtering. Discharges run in the upper W coated divertor do not show higher W concentrations than comparable discharges in the lower C based divertor. According to impurity transport calculations no strong high-Z accumulation is expected for the ITER standard scenario as long as the anomalous transport is at least as high as the neoclassical one.

Disruption avoidance by means of electron cyclotron waves

NASA Astrophysics Data System (ADS)

Esposito, B.; Granucci, G.; Maraschek, M.; Nowak, S.; Lazzaro, E.; Giannone, L.; Gude, A.; Igochine, V.; McDermott, R.; Poli, E.; Reich, M.; Sommer, F.; Stober, J.; Suttrop, W.; Treutterer, W.; Zohm, H.; ASDEX Upgrade, the; FTU Teams

2011-12-01

Disruptions are very challenging to ITER operation as they may cause damage to plasma facing components due to direct plasma heating, forces on structural components due to halo and eddy currents and the production of runaway electrons. Electron cyclotron (EC) waves have been demonstrated as a tool for disruption avoidance by a large set of recent experiments performed in ASDEX Upgrade and FTU using various disruption types, plasma operating scenarios and power deposition locations. The technique is based on the stabilization of magnetohydrodynamic (MHD) modes (mainly m/n = 2/1) through the localized injection of EC power on the resonant surface. This paper presents new results obtained in ASDEX Upgrade regarding stable operation above the Greenwald density achieved after avoidance of density limit disruptions by means of ECRH and suitable density feedback control (L-mode ohmic plasmas, Ip = 0.6 MA, Bt = 2.5 T) and NTM-driven disruptions at high-β limit delayed/avoided by means of both co-current drive (co-ECCD) and pure heating (ECRH) with power <=1.7 MW (H-mode NBI-heated plasmas, PNBI ~ 7.5 MW, Ip = 1 MA, Bt = 2.1 T, q95 ~ 3.6). The localized perpendicular injection of ECRH/ECCD onto a resonant surface leads to the delay and/or complete avoidance of disruptions. The experiments indicate the existence of a power threshold for mode stabilization to occur. An analysis of the MHD mode evolution using the generalized Rutherford equation coupled to the frequency and phase evolution equations shows that control of the modes is due to EC heating close to the resonant surface. The ECRH contribution (Δ'H term) is larger than the co-ECCD one in the initial and more important phase when the discharge is 'saved'. Future research and developments of the disruption avoidance technique are also discussed.

Optical improvements in the diagnosis of bladder cancer: implications for clinical practice.

PubMed

Schubert, Tina; Rausch, Steffen; Fahmy, Omar; Gakis, Georgios; Stenzl, Arnulf

2017-11-01

For over 100 years white-light cystoscopy has remained the gold-standard technique for the detection of bladder cancer (BCa). Some limitations in the detection of flat lesions (CIS), the differentiation between inflammation and malignancy, the inaccurate determination of the tumor margin status as well as the tumor depth, have led to a variety of technological improvements. The aim of this review is to evaluate the impact of these improvements in the diagnosis of BCa and their effectiveness in clinical practice. A systematic literature search was conducted according to the PRISMA statement to identify studies reporting on imaging modalities in the diagnosis of NMIBC between 2000 and 2017. A two-stage selection process was utilized to determine eligible studies. A total of 74 studies were considered for final analysis. Optical imaging technologies have emerged as an adjunct to white-light cystoscopy and can be classified according to their scope as macroscopic, microscopic and molecular. Macroscopic techniques including photodynamic diagnosis (PDD), narrow-band imaging (NBI) and the Storz Professional Image Enhancement System (IMAGE1 S, formerly known as SPIES) are similar to white-light cystoscopy, but are superior in the detection of bladder tumors by means of contrast enhancement. Especially the detection rate of very mute lesions in the bladder mucosa (CIS) could be significantly increased by the use of these methods. Microscopic imaging techniques like confocal laser endomicroscopy and optical coherence tomography permit a real-time high-resolution assessment of the bladder mucosa at a cellular and sub-cellular level with spatial resolutions similar to histology, enabling the surgeon to perform an 'optical biopsy'. Molecular techniques are based on the combination of optical imaging technologies with fluorescence labeling of cancer-specific molecular agents like antibodies. This labeling is intended to favor an optical distinction between benign and malignant tissue. Optical improvements of the standard white-light cystoscopy have proven their benefit in the detection of BCa and have found their way into clinical practice. Especially the combination of macroscopic and microscopic techniques may improve diagnostic accuracy. Nevertheless, HAL-PDD guided cystoscopy is the only approach approved for routine use in the diagnosis of BCa by most urological associations in the EU and USA to date.

Melt Origin Across a Rifted Continental Margin: A Case for Subduction-related Metasomatic Agents in the Lithospheric Source of Alkaline Basalt, Northwest Ross Sea, Antarctica

NASA Astrophysics Data System (ADS)

Panter, K. S.; Castillo, P.; Krans, S. R.; Deering, C. D.; McIntosh, W. C.; Valley, J. W.; Kitajima, K.; Kyle, P. R.; Hart, S. R.; Blusztajn, J.

2017-12-01

Alkaline magmatism within the West Antarctic rift system in the NW Ross Sea (NWRS) includes a chain of shield volcanoes extending 260 km along the coast, numerous seamounts located on the continental shelf and hundreds more within the oceanic Adare Basin. Dating and geochemistry confirm that the seamounts are Pliocene‒Pleistocene in age and petrogenetically akin to the mostly Miocene volcanism on the continent as well as to a much broader region of alkaline volcanism that altogether encompasses areas of West Antarctica, Zealandia and Australia. All of these regions were contiguous prior to Gondwana breakup at 100 Ma, suggesting that the magmatism is interrelated. Mafic alkaline magmas (> 6 wt.% MgO) erupted across the transition from continent to ocean in the NWRS show a remarkable systematic increase in Si-undersaturation, P2O5, Sr, Zr, Nb and light rare earth element (LREE) concentrations, LREE/HREE and Nb/Y ratios. Radiogenic isotopes also vary with Nd and Pb ratios increasing and Sr ratios decreasing ocean-ward. The variations are not explained by crustal contamination or by changes in degree of mantle partial melting but are likely a function of the thickness and age of mantle lithosphere. The isotopic signature of the most Si-undersaturated and incompatible element enriched basalts best represent the composition of the sub-lithospheric source with low 87Sr/86Sr (≤ 0.7030) and δ18Oolivine (≤ 5.0 ‰), high 143Nd/144Nd ( 0.5130) and 206Pb/204Pb (≥ 20) ratios. The isotopic `endmember' is derived from recycled material and was transferred to the lithospheric mantle by small degree melts to form amphibole-rich metasomes. Later melting of the metasomes produced silica-undersaturated liquids that reacted with the surrounding peridotite. This reaction occurred to a greater extent as the melt traversed through thicker and older lithosphere continent-ward. Ancient or more recent ( 550‒100 Ma) subduction along the margin of Gondwana supplied the recycled subduction-related residue to the asthenosphere. Metasomatism was triggered by major episodes of extension beginning in the Late Cretaceous but did not produce alkaline magmatism directly. Significant delay of 30 to 20 Ma between extension and magmatism was likely controlled by conductive heating and the rate of thermal migration at the base of the lithosphere.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isler, R.C.; Colchin, R.J.; Wade, M.R.

Collapses of stored energy are typically observed in low-density ({anti n}{sub e} {approx} 10{sup 13} cm{sup {minus}3}) extensively gettered ATF plasmas when the electron density rises to the ECH cutoff point, and the central heating is supplied only by neutral- beam-injection (NBI). However, the decline of stored energy can be avoided if the density is raised rapidly to about 5 {times} 10{sup 13} cm{sup {minus}3}. Three mechanisms have been proposed to explain the collapses: (1) impurity radiation, (2) excitation of an electron instability driven by the neutral beams, or (3) poor coupling of the beam ions to the thermal plasmas.more » Detailed spectroscopic studies of plasma cleanliness as a function of the gettering procedure have shown that radiation is an unlikely candidate for initiating collapses, although it may become an important loss mechanism once the electron temperature has fallen to a low level. No specific electron instability has yet been identified with injection, but recent experimental and computational work indicates that losses by shinethrough and charge exchange strongly influence the evolution of low-density plasmas. This report discusses the beam particle losses, thermal ions, and the evolution of radiation profiles.« less

Fusion product losses due to fishbone instabilities in deuterium JET plasmas

NASA Astrophysics Data System (ADS)

Kiptily, V. G.; Fitzgerald, M.; Goloborodko, V.; Sharapov, S. E.; Challis, C. D.; Frigione, D.; Graves, J.; Mantsinen, M. J.; Beaumont, P.; Garcia-Munoz, M.; Perez von Thun, C.; Rodriguez, J. F. R.; Darrow, D.; Keeling, D.; King, D.; McClements, K. G.; Solano, E. R.; Schmuck, S.; Sips, G.; Szepesi, G.; Contributors, JET

2018-01-01

During development of a high-performance hybrid scenario for future deuterium-tritium experiments on the Joint European Torus, an increased level of fast ion losses in the MeV energy range was observed during the instability of high-frequency n  =  1 fishbones. The fishbones are excited during deuterium neutral beam injection combined with ion cyclotron heating. The frequency range of the fishbones, 10-25 kHz, indicates that they are driven by a resonant interaction with the NBI-produced deuterium beam ions in the energy range  ⩽120 keV. The fast particle losses in a much higher energy range are measured with a fast ion loss detector, and the data show an expulsion of deuterium plasma fusion products, 1 MeV tritons and 3 MeV protons, during the fishbone bursts. An MHD mode analysis with the MISHKA code combined with the nonlinear wave-particle interaction code HAGIS shows that the loss of toroidal symmetry caused by the n  =  1 fishbones affects strongly the confinement of non-resonant high energy fusion-born tritons and protons by perturbing their orbits and expelling them. This modelling is in a good agreement with the experimental data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Jinping P.; Garofalo, Andrea M.; Gong, Xianzu Z.

Recent EAST/DIII-D joint experiments on the high poloidal betamore » $${{\\beta}_{\\text{P}}}$$ regime in DIII-D have extended operation with internal transport barriers (ITBs) and excellent energy confinement (H 98y2 ~ 1.6) to higher plasma current, for lower q 95 ≤ 7.0, and more balanced neutral beam injection (NBI) (torque injection < 2 Nm), for lower plasma rotation than previous results. Transport analysis and experimental measurements at low toroidal rotation suggest that the E × B shear effect is not key to the ITB formation in these high $${{\\beta}_{\\text{P}}}$$ discharges. Experiments and TGLF modeling show that the Shafranov shift has a key stabilizing effect on turbulence. Extrapolation of the DIII-D results using a 0D model shows that with the improved confinement, the high bootstrap fraction regime could achieve fusion gain Q = 5 in ITER at $${{\\beta}_{\\text{N}}}$$ ~ 2.9 and q 95 ~ 7. With the optimization of q(0), the required improved confinement is achievable when using 1.5D TGLF-SAT1 for transport simulations. Furthermore, results reported in this paper suggest that the DIII-D high $${{\\beta}_{\\text{P}}}$$ scenario could be a candidate for ITER steady state operation.« less

Overview of MST Research

NASA Astrophysics Data System (ADS)

Sarff, J. S.; MST Team

2011-10-01

MST progress in advancing the RFP for (1) fusion plasma confinement with minimal external magnetization, (2) toroidal confinement physics, and (3) basic plasma physics is summarized. New tools and diagnostics are accessing physics barely studied in the RFP. Several diagnostic advances are important for ITER/burning plasma. A 1 MW neutral beam injector operates routinely for fast ion, heating, and transport investigations. Energetic ions are also created spontaneously by tearing mode reconnection, reminiscent of astrophysical plasmas. Classical confinement of impurity ions is measured in reduced-tearing plasmas. Fast ion slowing-down is also classical. Alfven-eigenmode-like activity occurs with NBI, but apparently not TAE. Stellarator-like helical structure appears in the core of high current plasmas, with improved confinement characteristics. FIR interferometry, Thomson scattering, and HIBP diagnostics are beginning to explore microturbulence scales, an opportunity to exploit the RFP's high beta and strong magnetic shear parameter space. A programmable power supply for the toroidal field flexibly explores scenarios from advanced inductive profile control to low current tokamak operation. A 1 MW 5.5 GHz source for electron Bernstein wave injection is nearly complete to investigate heating and current drive in over-dense plasmas. Supported by DOE and NSF.

Control of ITBs in Fusion Self-Heated Plasmas

NASA Astrophysics Data System (ADS)

Panta, Soma; Newman, David; Terry, Paul; Sanchez, Raul

2015-11-01

Simple dynamical models have been able to capture a remarkable amount of the dynamics of the transport barriers found in many devices, including the often disconnected nature of the electron thermal transport channel sometimes observed in the presence of a standard (``ion channel'') barrier. By including in this rich though simple dynamic transport model an evolution equation for electron fluctuations we have previously investigated the interaction between the formation of the standard ion channel barrier and the somewhat less common electron channel barrier. The electron channel formation and evolution is even more sensitive to the alignment of the various gradients making up the sheared radial electric field then the ion barrier is. Because of this sensitivity and coupling of the barrier dynamics, the dynamic evolution of the fusion self-heating profile can have a significant impact on the barrier location and dynamics. To investigate this, self-heating has been added this model and the impact of the self-heating on the formation and controllability of the various barriers is explored. It has been found that the evolution of the heating profiles can suppress or collapse the electron channel barrier. NBI and RF schemes will be investigated for profile/barrier control.

ELM Mitigation in Low-rotation ITER Baseline Scenario Plasmas on DIII-D with Deuterium Pellet Injection

NASA Astrophysics Data System (ADS)

Baylor, L. R.

2016-10-01

ELM mitigation using high frequency D2 pellet ELM pacing has been demonstrated in ITER baseline scenario plasmas on DIII D with low rotation obtained with low NBI input torque. The ITER burning plasmas will have relatively low input torque and are expected to have low rotation. ELM mitigation by on-demand pellet ELM triggering has not been observed before in these conditions. New experiments on DIII-D in these conditions with 90 Hz D2 pellets have shown that significant mitigation of the divertor ELM peak heat flux by a factor of 8 is possible without detrimental effects to the plasma confinement. High-Z impurity accumulation is dramatically reduced at all input torques from 0.1 to 2.5 N-m. Fueling with high field side injection of D2 pellets has been employed to demonstrate that density buildup can be obtained simultaneously with ELM mitigation. The implications are that rapid pellet injection remains a promising technique to trigger on-demand ELMs in low rotating plasmas with greatly reduced peak flux while preventing impurity accumulation in ITER. Supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698.

Nondestructive Optical Sensing of Flavonols and Chlorophyll in White Head Cabbage (Brassica oleracea L. var. capitata subvar. alba) Grown under Different Nitrogen Regimens.

PubMed

Agati, Giovanni; Tuccio, Lorenza; Kusznierewicz, Barbara; Chmiel, Tomasz; Bartoszek, Agnieszka; Kowalski, Artur; Grzegorzewska, Maria; Kosson, Ryszard; Kaniszewski, Stanislaw

2016-01-13

A multiparametric optical sensor was used to nondestructively estimate phytochemical compounds in white cabbage leaves directly in the field. An experimental site of 1980 white cabbages (Brassica oleracea L. var. capitata subvar. alba), under different nitrogen (N) treatments, was mapped by measuring leaf transmittance and chlorophyll fluorescence screening in one leaf/cabbage head. The provided indices of flavonols (FLAV) and chlorophyll (CHL) displayed the opposite response to applied N rates, decreasing and increasing, respectively. The combined nitrogen balance index (NBI = CHL/FLAV) calculated was able to discriminate all of the plots under four N regimens (0, 100, 200, and 400 kg/ha) and was correlated with the leaf N content determined destructively. CHL and FLAV were properly calibrated against chlorophyll (R(2) = 0.945) and flavonol (R(2) = 0.932) leaf contents, respectively, by using a homographic fit function. The proposed optical sensing of cabbage crops can be used to estimate the N status of plants and perform precision fertilization to maintain acceptable crop yield levels and, additionally, to rapidly detect health-promoting flavonol antioxidants in Brassica plants.

Development of Web Interfaces for Analysis Codes

NASA Astrophysics Data System (ADS)

Emoto, M.; Watanabe, T.; Funaba, H.; Murakami, S.; Nagayama, Y.; Kawahata, K.

Several codes have been developed to analyze plasma physics. However, most of them are developed to run on supercomputers. Therefore, users who typically use personal computers (PCs) find it difficult to use these codes. In order to facilitate the widespread use of these codes, a user-friendly interface is required. The authors propose Web interfaces for these codes. To demonstrate the usefulness of this approach, the authors developed Web interfaces for two analysis codes. One of them is for FIT developed by Murakami. This code is used to analyze the NBI heat deposition, etc. Because it requires electron density profiles, electron temperatures, and ion temperatures as polynomial expressions, those unfamiliar with the experiments find it difficult to use this code, especially visitors from other institutes. The second one is for visualizing the lines of force in the LHD (large helical device) developed by Watanabe. This code is used to analyze the interference caused by the lines of force resulting from the various structures installed in the vacuum vessel of the LHD. This code runs on PCs; however, it requires that the necessary parameters be edited manually. Using these Web interfaces, users can execute these codes interactively.

Kinetic electromagnetic instabilities in an ITB plasma with weak magnetic shear

NASA Astrophysics Data System (ADS)

Chen, W.; Yu, D. L.; Ma, R. R.; Shi, P. W.; Li, Y. Y.; Shi, Z. B.; Du, H. R.; Ji, X. Q.; Jiang, M.; Yu, L. M.; Yuan, B. S.; Li, Y. G.; Yang, Z. C.; Zhong, W. L.; Qiu, Z. Y.; Ding, X. T.; Dong, J. Q.; Wang, Z. X.; Wei, H. L.; Cao, J. Y.; Song, S. D.; Song, X. M.; Liu, Yi.; Yang, Q. W.; Xu, M.; Duan, X. R.

2018-05-01

Kinetic Alfvén and pressure gradient driven instabilities are very common in magnetized plasmas, both in space and the laboratory. These instabilities will be easily excited by energetic particles (EPs) and/or pressure gradients in present-day fusion and future burning plasmas. This will not only cause the loss and redistribution of the EPs, but also affect plasma confinement and transport. Alfvénic ion temperature gradient (AITG) instabilities with the frequency ω_BAE<ω<ω_TAE and the toroidal mode numbers n=2{-}8 are found to be unstable in NBI internal transport barrier plasmas with weak shear and low pressure gradients, where ω_BAE and ω_TAE are the frequencies of the beta- and toroidicity-induced Alfvén eigenmodes, respectively. The measured results are consistent with the general fishbone-like dispersion relation and kinetic ballooning mode equation, and the modes become more unstable the smaller the magnetic shear is in low pressure gradient regions. The interaction between AITG activity and EPs also needs to be investigated with greater attention in fusion plasmas, such as ITER (Tomabechi and The ITER Team 1991 Nucl. Fusion 31 1135), since these fluctuations can be enhanced by weak magnetic shear and EPs.

Profile measurements of the electron temperature on the ASDEX Upgrade, COMPASS, and ISTTOK tokamak using Thomson scattering, triple, and ball-pen probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamek, J., E-mail: adamek@ipp.cas.cz; Horacek, J.; Bilkova, P.

The ball-pen probe (BPP) technique is used successfully to make profile measurements of the electron temperature on the ASDEX Upgrade (Axially Symmetric Divertor Experiment), COMPASS (COMPact ASSembly), and ISTTOK (Instituto Superior Tecnico TOKamak) tokamak. The electron temperature is provided by a combination of the BPP potential (Φ{sub BPP}) and the floating potential (V{sub fl}) of the Langmuir probe (LP), which is compared with the Thomson scattering diagnostic on ASDEX Upgrade and COMPASS. Excellent agreement between the two diagnostics is obtained for circular and diverted plasmas and different heating mechanisms (Ohmic, NBI, ECRH) in deuterium discharges with the same formula T{submore » e} = (Φ{sub BPP} − V{sub fl})/2.2. The comparative measurements of the electron temperature using BPP/LP and triple probe (TP) techniques on the ISTTOK tokamak show good agreement of averaged values only inside the separatrix. It was also found that the TP provides the electron temperature with significantly higher standard deviation than BPP/LP. However, the resulting values of both techniques are well in the phase with the maximum of cross-correlation function being 0.8.« less

Overview of MST Research

NASA Astrophysics Data System (ADS)

Sarff, J. S.

2016-10-01

MST progress in advancing the RFP for (1) fusion plasma confinement with ohmic heating and minimal external magnetization, (2) predictive capability in toroidal confinement physics, and (3) basic plasma physics is summarized. Validation of key plasma models is a program priority. Programmable power supplies (PPS) are being developed to maximize inductive capability. Well-controlled flattops with current as low as 0.02 MA are produced with an existing PPS, and Ip <= 0.8 MA is anticipated with a second PPS under construction. The Lundquist number spans S =10(4 - 9) for 0.02-0.8 MA, allowing nonlinear MHD validation using NIMROD and DEBS at low S to be connected to highest S experiments. The PPS also enables MST tokamak operation for studying transients and runaway electron suppression with RMPs. Gyrokinetic modeling with GENE predicts unstable TEM in improved-confinement plasmas. Fluctuations are measured with TEM properties including a density-gradient threshold larger than for tokamak plasmas. Probe measurements hint that drift waves are also excited via the turbulent cascade in standard RFP plasmas. Turbulent energization of an electron tail occurs during sawtooth reconnection. New diagnostics are being developed to measure the energetic ion profile and transport from EP instabilities with NBI. Supported by US DoE and NSF.

Preliminary Geochemical Data for the Diabase Dykes from the Izmir-Ankara-Erzincan Suture Belt, Central Anatolia

NASA Astrophysics Data System (ADS)

Balcı, Uǧur; Sayıt, Kaan

2017-04-01

The Izmir-Ankara-Erzincan Suture Belt preserves oceanic and continental fragments originated from the closure of the northern branch of Neotethys. In the Bogazkale area (Central Anatolia), the pieces of the Neotethyan oceanic lithosphere exist in a chaotic manner, forming an ophiolitic mélange. Within the mélange, diabase dykes occur, which are found to cut various types of oceanic lithospheric rocks, including pillow basalts, gabbros and serpentinized ultramafics. We here present the preliminary geochemical results obtained from the diabase dykes and put some constraints on their petrogenesis. The investigated diabase dykes are chiefly composed of plagioclase and a mafic phase, which is clinopyroxene and/or hornblende. A detailed examination reveals two petrographic types on the basis of predominating mafic mineral phase, namely clinopyroxene-dominated Type 1, and hornblende-dominated Type 2. Ophitic to sub-ophitic textures, where lath-shaped plagioclase crystals are enclosed by clinopyroxene, can be observed in almost all Type 1 dykes. In Type 2 samples, altered mafic phases can be seen enclosed within plagioclase crystals, forming poikilitic texture. Polysynthetic twinning is common in plagioclase. Hornblende occasionally displays simple twinning. Both types appear to have been variably affected by low-grade hydrothermal alteration as reflected by the presence of secondary mineral phases, such as chlorite, epidote, prehnite, and actinolite. The whole-rock geochemistry appear to be consistent with the petrographical grouping, revealing distinct immobile trace element systematics for the two types. Both types have basaltic composition with sub-alkaline characteristics (Nb/Y=0.2-0.3 for Type 1; Nb/Y=0.02-0.08 for Type 2). The relatively low MgO contents of the dykes suggest that they do not represent primary magmas, but evolved through fractionation of mafic phases. In the N-MORB normalized diagrams, Type 2 diabases exhibit marked negative Nb anomalies, with HFSE abundances around or slightly more enriched than N-MORB. Type 1 diabases, on the other hand, do not possess any negative Nb anomalies and display enrichment in highly incompatible elements. In the chondrite-normalized diagrams, Type 1 diabases display slight LREE enrichment relative to HREE, whereas Type 2 diabases show flat to slightly LREE-depleted patterns. The N-MORB-like Nb contents of Type 2 dykes suggest that they have been derived from depleted asthenopheric mantle source. The marked enrichment of Th and La over Nb indicates that their source has been metasomatized by slab-derived fluids/melts. However, the enrichment in highly incompatible elements in Type 1 dykes implies their derivation from a relatively enriched source region and/or small degrees of partial melting. Trace element systematics suggest that Type 2 diabases may have formed in an oceanic back-arc basin environment, whereas Type 1 diabases have been generated in a mid-ocean ridge or alternatively in an oceanic back-arc basin.

Long-Term Safety and Tolerability of Valbenazine (NBI-98854) in Subjects with Tardive Dyskinesia and a Diagnosis of Schizophrenia or Mood Disorder

PubMed Central

Josiassen, Richard C.; Kane, John M.; Liang, Grace S.; Burke, Joshua; O’Brien, Christopher F.

2017-01-01

Background The short-term safety profile of once-daily valbenazine (NBI-98854) has been evaluated in several double-blind, placebo-controlled (DBPC) trials in adults with tardive dyskinesia (TD) who had a diagnosis of schizophrenia/schizoaffective (SCHZ) disorder or mood disorder. Studies with longer treatment duration (up to 48 weeks) were conducted to evaluate the long-term safety of this novel drug in subjects with TD. Methods The pooled long-term exposure (LTE) population included valbenazine-treated subjects from 3 studies: KINECT (NCT01688037: 6-week DBPC, 6-week open-label); KINECT 3 (NCT02274558: 6-week DBPC, 42-week blinded extension, 4-week drug-free follow-up); KINECT 4 (NCT02405091: 48-week open-label, 4-week drug-free follow-up). Safety assessments included adverse events (AEs), laboratory tests, vital signs, electrocardiograms (ECGs), and extrapyramidal symptom (EPS) scales. Psychiatric stability was monitored using the Positive and Negative Syndrome Scale (PANSS) and Calgary Depression Scale for Schizophrenia (CDSS) (SCHZ subgroup), as well as the Montgomery-Åsberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) (mood subgroup). All data were analyzed descriptively. Results The LTE population included 430 subjects (KINECT, n = 46; KINECT 3, n = 220; KINECT 4, n = 164), 71.7% with SCHZ and 28.3% with a mood disorder; 85.5% were taking an antipsychotic (atypical only, 69.8%; typical only or typical + atypical, 15.7%). In the LTE population, treatment-emergent AEs (TEAEs) and discontinuations due to AEs were reported in 66.5% and 14.7% of subjects, respectively. The TEAE incidence was lower in the SCHZ subgroup (64.4%) than in the mood subgroup (71.9%). The 3 most common TEAEs in the SCHZ subgroup were urinary tract infection (UTI, 6.1%), headache (5.8%), and somnolence (5.2%). The 3 most common TEAEs in the mood subgroup were headache (12.4%), UTI (10.7%), and somnolence (9.1%). Mean score changes from baseline to end of treatment (Week 48) indicated that psychiatric stability was maintained in the SCHZ subgroup (PANSS Total, -3.4; PANSS Positive, -1.1; PANSS Negative, -0.1; PANSS General Psychopathology, -2.2; CDSS total, -0.4) and the mood subgroup (MADRS Total, 0.0; YMRS Total, -1.2). These scores remained generally stable during the 4-week drug-free follow-up periods. In the LTE population, mean changes in laboratory parameters, vital signs, ECG, and EPS scales were generally minimal and not clinically significant. Conclusion Valbenazine appeared to be well tolerated in adults with TD who received up to 48 weeks of treatment. In addition to long-term efficacy results (presented separately), these results suggest that valbenazine may be appropriate for the long-term management of TD regardless of underlying psychiatric diagnosis (SCHZ disorder or mood disorder). PMID:28839341

Long-Term Safety and Tolerability of Valbenazine (NBI-98854) in Subjects with Tardive Dyskinesia and a Diagnosis of Schizophrenia or Mood Disorder.

PubMed

Josiassen, Richard C; Kane, John M; Liang, Grace S; Burke, Joshua; O'Brien, Christopher F

2017-08-01

The short-term safety profile of once-daily valbenazine (NBI-98854) has been evaluated in several double-blind, placebo-controlled (DBPC) trials in adults with tardive dyskinesia (TD) who had a diagnosis of schizophrenia/schizoaffective (SCHZ) disorder or mood disorder. Studies with longer treatment duration (up to 48 weeks) were conducted to evaluate the long-term safety of this novel drug in subjects with TD. The pooled long-term exposure (LTE) population included valbenazine-treated subjects from 3 studies: KINECT (NCT01688037: 6-week DBPC, 6-week open-label); KINECT 3 (NCT02274558: 6-week DBPC, 42-week blinded extension, 4-week drug-free follow-up); KINECT 4 (NCT02405091: 48-week open-label, 4-week drug-free follow-up). Safety assessments included adverse events (AEs), laboratory tests, vital signs, electrocardiograms (ECGs), and extrapyramidal symptom (EPS) scales. Psychiatric stability was monitored using the Positive and Negative Syndrome Scale (PANSS) and Calgary Depression Scale for Schizophrenia (CDSS) (SCHZ subgroup), as well as the Montgomery-Åsberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) (mood subgroup). All data were analyzed descriptively. The LTE population included 430 subjects (KINECT, n = 46; KINECT 3, n = 220; KINECT 4, n = 164), 71.7% with SCHZ and 28.3% with a mood disorder; 85.5% were taking an antipsychotic (atypical only, 69.8%; typical only or typical + atypical, 15.7%). In the LTE population, treatment-emergent AEs (TEAEs) and discontinuations due to AEs were reported in 66.5% and 14.7% of subjects, respectively. The TEAE incidence was lower in the SCHZ subgroup (64.4%) than in the mood subgroup (71.9%). The 3 most common TEAEs in the SCHZ subgroup were urinary tract infection (UTI, 6.1%), headache (5.8%), and somnolence (5.2%). The 3 most common TEAEs in the mood subgroup were headache (12.4%), UTI (10.7%), and somnolence (9.1%). Mean score changes from baseline to end of treatment (Week 48) indicated that psychiatric stability was maintained in the SCHZ subgroup (PANSS Total, -3.4; PANSS Positive, -1.1; PANSS Negative, -0.1; PANSS General Psychopathology, -2.2; CDSS total, -0.4) and the mood subgroup (MADRS Total, 0.0; YMRS Total, -1.2). These scores remained generally stable during the 4-week drug-free follow-up periods. In the LTE population, mean changes in laboratory parameters, vital signs, ECG, and EPS scales were generally minimal and not clinically significant. Valbenazine appeared to be well tolerated in adults with TD who received up to 48 weeks of treatment. In addition to long-term efficacy results (presented separately), these results suggest that valbenazine may be appropriate for the long-term management of TD regardless of underlying psychiatric diagnosis (SCHZ disorder or mood disorder).

Geochemical Relationships between Middle- to Upper-Crustal Exposures of the Alisitos Oceanic Arc (Baja California, Mexico): An Outstanding Field Analog to Active Extensional Oceanic Arcs

NASA Astrophysics Data System (ADS)

Morris, R.; DeBari, S. M.; Busby, C.; Medynski, S.

2016-12-01

The southern volcano-bounded basin of the Rosario segment of the Cretaceous Alisitos oceanic arc provides outstanding 3-D exposures of an extensional arc, where crustal generation processes are recorded in the upper-crustal volcanic units and underlying middle-crustal plutonic rocks. Geochemical linkages between exposed crustal levels provide an analog for extensional arc systems such as the Izu-Bonin-Mariana (IBM) Arc. Upper-crustal units comprise a 3-5 km thick volcanic-volcaniclastic stratigraphy with hypabyssal intrusions. Deep-seated plutonic rocks intrude these units over a transition of <500m, where rafted volcanic blocks and evidence of magma mingling are exposed. Thermobarometry suggests <6 km emplacement depths. Compositional ranges (basalt to rhyolite) and mineral assemblages are similar in both middle-crustal and upper-crustal units, with striking compositional overlap. The most mafic compositions occur in upper-crustal hypabyssal units, and as amphibole cumulates in the plutonic rocks ( 51% SiO2). The most felsic compositions occur in welded ignimbrites and a tonalite pluton ( 71% SiO2). All units are low K with flat REE patterns, and show LILE enrichment and HFSE depletion. Trace element ratios show limited variation throughout the crustal section. Zr/Y and Nb/Y ratios are similar to the Izu active ( 3 Ma to present) zone of extension immediately behind the arc front, suggesting comparable mantle melt % during extension. Th/Zr ratios are more enriched in Alisitos compared to Izu, suggesting greater subducted sediment input. The Alisitos crustal section shows a limited range in ɛNd (5.7-7.1), but a wider range in 87Sr/86Sr (0.7035-0.7055) and 206Pb/204Pb (18.12-19.12); the latter is likely alteration effects. Arc magmas were derived from a subduction-modified MORB mantle source, less depleted than Izu arc front and less enriched than the rear arc, but is a good match with the zone of extension that lies between. Differentiation occurred in a closed system (i.e., fractional crystallization/self-melting with back mixing), producing the entire crustal section in <3 Ma.

DiMES Tests of W Leading Edge Power Loading in DIII-D

NASA Astrophysics Data System (ADS)

Nygren, R. E.; Watkins, J. G.; Rudakov, D. L.; Lasnier, C. J.; Pitts, R. A.; Stangeby, P. C.

2015-11-01

In a transient melt experiment in JET, the power to a ~1-mm-high leading edge on a W lamella in the bulk-W outer divertor was lower than expected from the geometry by factors of 5 and 2 for L-mode and H-mode discharges, respectively. We checked this surprising result in DIII-D with 3 W blocks (10 mm square) mounted radially side-by-side in DiMES with leading edges of 0.0, 0.3, 1.0 mm, single null L-mode plasmas, OSP just outside ``0.0'' block, limited scans (NBI+ECH), B-field incident at 1.5° or 2.5°, and viewed, as in JET, from above with 0.2mm/pixel resolution IRTV. Langmuir probes measured parallel power to the target. We compared probe and IR data with a detailed thermal model of the blocks and concluded provisionally that we did not reproduce the power deficit found in JET. Blurred IR images complicated fitting of temperature distributions from the thermal model. We plan an experiment with both L- and H-mode He plasmas before the APS meeting. Supported by US DOE under DE-AC04-94AL85000, 44500007360, DE-AC52-07NA27344, and DE-FC02-04ER54698.

Integrated Scenario Modeling of NSTX Advanced Plasma Configurations

NASA Astrophysics Data System (ADS)

Kessel, Charles; Synakowski, Edward

2003-10-01

The Spherical Torus will provide an attractive fusion energy source if it can demonstrate the following major features: high elongation and triangularity, 100% non-inductive current with a credible path to high bootstrap fractions, non-solenoidal startup and current rampup, high beta with stabilization of RWM instabilities, and sufficiently high energy confinement. NSTX has specific experimental milestones to examine these features, and integrated scenario modeling is helping to understand how these configurations might be produced and what tools are needed to access this operating space. Simulations with the Tokamak Simulation Code (TSC), CURRAY, and JSOLVER/BALMSC/PEST2 have identified fully non-inductively sustained, high beta plasmas that rely on strong plasma shaping accomplished with a PF coil modification, off-axis current drive from Electron Bernstein Waves (EBW), flexible on-axis heating and CD from High Harmonic Fast Wave (HHFW) and Neutral Beam Injection (NBI), and density control. Ideal MHD stability shows that with wall stabilization through plasma rotation and/or RWM feedback coils, a beta of 40% is achievable, with 100% non-inductive current sustained for 4 current diffusion times. Experimental data and theory are combined to produce a best extrapolation to these regimes, which is continuously improved as the discharges approach these parameters, and theoretical/computational methods expand. Further investigations and development for integrated scenario modeling on NSTX is discussed.

Laser Backscatter and Propagation in Low-Density Ta2O5 and SiO2 Foams

NASA Astrophysics Data System (ADS)

Mariscal, Derek; Patankar, Siddarth; Goyon, Clement; Baker, Kevin; MacLaren, Stephan; Hammer, Jim; Baumann, Ted; Amendt, Peter; Menapace, Joseph; Berger, Robert; Afeyan, Bedros; Tabak, Max; Kim, Sung Ho; Dixit, Sham; Moody, John; Jones, Ogden; LLNL Team; Polymath Research Inc. Collaboration

2016-10-01

Recent experiments at the Jupiter Laser Facility at LLNL have investigated the propagation and backscatter of a laser in low-density foams (2-30 mg/cc) comprised of Ta2O5 and SiO2. The foams fill the volume of thin polyimide tubes (2 mm diameter, 0.5-2 mm length), while the laser is directed down the axis of the tubes. Time-resolved Stimulated Brillouin Scattering (SBS) spectrum, time-integrated Stimulated Raman Scattering (SRS) spectrum and power were measured in the focusing cone. In addition Near Backscatter Imaging (NBI) assessed SBS outside the focusing cone while X-ray diagnostics were used to assess laser propagation through the foams. While this experiment uses a 2-omega laser drive, the pulse shape, irradiance, and the ratio ne/nc are scaled to be similar to future tests using Ta2O5 foams at the NIF. Experimental results are directly compared to calculations of laser propagation and backscattered spectra. This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, with funding support from the Laboratory Directed Research and Development Program 15-ERD-073.

Study of electron transport across the magnetic filter of NIO1 negative ion source

NASA Astrophysics Data System (ADS)

Veltri, P.; Sartori, E.; Cavenago, M.; Serianni, G.; Barbisan, M.; Zaniol, B.

2017-08-01

In the framework of the accompanying activities in support to the ITER NBI test facility, a relatively compact radiofrequency (RF) ion source, named NIO1 (Negative Ion Optimization, phase 1) was developed in Padua, Italy, in collaboration between Consorzio RFX and INFN. Negative hydrogen ions are formed in a cold, inductively coupled plasma with a 2MHz, 2.5 kW external antenna. A low electron energy is necessary to increase the survival probability of negative ions in the proximity of the extraction area. This goal is accomplished by means of a transversal magnetic field, confining the high energy electrons better than the colder electrons. In NIO1, this filter field can cover different topologies, exploiting different set of magnets and high current paths. In this contribution we study the property of the plasma in the vicinity of the extraction region for two different B field configurations. For this experiment the source was operated in pure volume conditions, in hydrogen and oxygen plasmas. The experimental data, measured by spectroscopic means, is interpreted also with the support of finite element analyses simulations of the magnetic field and a dedicated particle in cell (PIC) numerical model for the electron transport across it, including Coulomb and gas collisions.

Effect of Fe doping on structural and impedance properties of PZTFN ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Arvind, E-mail: arvindmse07311209.in@gmail.com; Pal, Vijayeta; Mishra, S. K.

2016-05-06

An attempts have been made to synthesis the ceramics Pb{sub 1-3x/2} Fe{sub x}(Zr{sub 0.52}Ti{sub 0.48}){sub 1-5y/4} NbyO{sub 3} abbreviated as (PFZTN) for x = 1-6 mol% and y = 5.5 mol% by a semi-wet route. In the present paper, we have investigated the effect of Fe doping on structural and electrical properties of the PFZTN ceramics. X-ray diffraction (XRD) patterns reveal that PFZTN ceramics are single phase in nature. However, for x = 0.05 and 0.06, a secondary phase appears as discernible from the XRD profiles. Rietveld analysis of the powder diffraction data shows the presence of coexistence of tetragonal (P4mm spacemore » group) and rhombohedral phases (R3c space group) occurs near the morphotropic phase boundary (MPB) at x ≥ = 0.05. The log-log plots show that the conductivity increases with increase of temperature. The ac conductivity becomes sensitive at high frequency region and shifted towards higher frequency side with increasing temperature. It is observed that the activation energy (Ea) decreases with increasing frequency. This complex perovskite structure can be used as a multilayer ceramic capacitors and electromechanical transducers.« less

Fast ion beta limit measurements by collimated neutron detection in MST plasmas

NASA Astrophysics Data System (ADS)

Capecchi, William; Anderson, Jay; Bonofiglo, Phillip; Kim, Jungha; Sears, Stephanie

2015-11-01

Fast ion orbits in the reversed field pinch (RFP) are well ordered and classically confined despite magnetic field stochasticity generated by multiple tearing modes. Classical TRANSP modeling of a 1MW tangentially injected hydrogen neutral beam in MST deuterium plasmas predicts a core-localized fast ion density that can be up to 25% of the electron density and a fast ion beta of many times the local thermal beta. However, neutral particle analysis of an NBI-driven mode (presumably driven by a fast ion pressure gradient) shows mode-induced transport of core-localized fast ions and a saturated fast ion density. The TRANSP modeling is presumed valid until the onset of the beam-driven mode and gives an initial estimate of the volume-averaged fast ion beta of 1-2% (local core value up to 10%). A collimated neutron detector for fusion product profile measurements will be used to determine the spatial distribution of fast ions, allowing for a first measurement of the critical fast-ion pressure gradient required for mode destabilization. Testing/calibration data and initial fast-ion profiles will be presented. Characterization of both the local and global fast ion beta will be done for deuterium beam injection into deuterium plasmas for comparison to TRANSP predictions. Work supported by US DOE.

Stability of Elevated-qmin Steady-State Scenarios on DIII-D

NASA Astrophysics Data System (ADS)

Holcomb, C. T.; Victor, B.; Ferron, J. R.; Luce, T. C.; Schuster, E.

2016-10-01

Limits to high performance steady-state operation with qmin >1.4 and βN <= 3.5 are identified and explained. Various βN and q-profile histories were produced while testing feedback control of these profiles. Ten pulses had no core MHD at βN=3.4-3.5, with qmin=1.4-1.8, and q95=5-5.8. These have predicted ideal-wall kink βN limits between 4 and 5. One pulse had an n=1 tearing mode (TM) at βN=3.5 with no clear trigger. Five pulses developed n=1 TMs when βN=2, qmin=2, and q95=4.7. Stability calculations for these latter cases will be shown. In seven other shots, additional NBI power from sources with more normal injection was used, and these had off-axis fishbone (OAFB) modes at βN=3.5. These sources produce more large-radius trapped ions whose precession can drive OAFB. Preliminary analysis suggests a threshold power or voltage exists. In some cases OAFB appear to trigger n=1 TMs. These studies seek to clarify the operational limits of a steady-state scenario for next step devices. Supported by US DOE under DE-AC52-07NA27344, DE-FC02-04ER54698, DE-FG02-09ER55064.

Highlights of the Alcator C-Mod Research Campaign

NASA Astrophysics Data System (ADS)

Greenwald, Martin; Alcator Team

2011-10-01

Alcator C-Mod has completed an experimental campaign focusing on broad scientific issues with particular emphasis on ITER needs and requests. Experiments with no NBI torque have investigated spontaneous flow reversal, creation of transport barriers aided by the shear of intrinsic rotation and a variety of RF flow drive schemes. Studies of I-mode have found conditions where a wide operating regime opens up, allowing easy access to long-lived, high-performance discharges with L-mode like particle confinement. We are validating the EPED and BOUT++ models for pedestal height/width and ELM onset using extended parameter scans in ELMy H-mode. The challenge of high-Z impurity generation with ICRF is being addressed first by deployment of a novel antenna whose current straps and antenna box are perpendicular to the total magnetic field -second by studies of the modification of edge impurity transport, where fine-scale Er structures in the SOL in the presence of ICRF heating have been found. LH current drive has produced non-inductive reversed shear regimes at n ~ 5x1019 which exhibit electron temperature ITBs. The first observations have been made of in-tokamak production of divertor tungsten nano-structures (fuzz), which had previously been seen only in linear laboratory experiments. Supported by DoE DE-FC02-99ER54512.

Study of Stark Effect in n-doped 1.55 μm InN0.92yP1-1.92yBiy/InP MQWs

NASA Astrophysics Data System (ADS)

Bilel, C.; Chakir, K.; Rebey, A.; Alrowaili, Z. A.

2018-05-01

The effect of an applied electric field on electronic band structure and optical absorption properties of n-doped InN0.92y P1-1.92y Bi y /InP multiple quantum wells (MQWs) was theoretically studied using a self-consistent calculation combined with the 16-band anti-crossing model. The incorporation of N and Bi atoms into an InP host matrix leads to rapid reduction of the band gap energy covering a large infrared range. The optimization of the well parameters, such as the well/barrier widths, N/Bi compositions and doping density, allowed us to obtain InN0.92y P1-1.92y Bi y /InP MQWs operating at the wavelength 1.55 μm. Application of the electric field causes a red-shift of the fundamental transition energy T 1 accompanied by a significant change in the spatial distribution of confined electron density. The Stark effect on the absorption coefficient of n-doped InN0.92y P1-1.92y Bi y /InP MQWs was investigated. The Bi composition of these MQWs was adjusted for each electric field value in order to maintain the wavelength emission at 1.55 μm.

Advances in the high bootstrap fraction regime on DIII-D towards the Q = 5 mission of ITER steady state

DOE PAGES

Qian, Jinping P.; Garofalo, Andrea M.; Gong, Xianzu Z.; ...

2017-03-20

Recent EAST/DIII-D joint experiments on the high poloidal betamore » $${{\\beta}_{\\text{P}}}$$ regime in DIII-D have extended operation with internal transport barriers (ITBs) and excellent energy confinement (H 98y2 ~ 1.6) to higher plasma current, for lower q 95 ≤ 7.0, and more balanced neutral beam injection (NBI) (torque injection < 2 Nm), for lower plasma rotation than previous results. Transport analysis and experimental measurements at low toroidal rotation suggest that the E × B shear effect is not key to the ITB formation in these high $${{\\beta}_{\\text{P}}}$$ discharges. Experiments and TGLF modeling show that the Shafranov shift has a key stabilizing effect on turbulence. Extrapolation of the DIII-D results using a 0D model shows that with the improved confinement, the high bootstrap fraction regime could achieve fusion gain Q = 5 in ITER at $${{\\beta}_{\\text{N}}}$$ ~ 2.9 and q 95 ~ 7. With the optimization of q(0), the required improved confinement is achievable when using 1.5D TGLF-SAT1 for transport simulations. Furthermore, results reported in this paper suggest that the DIII-D high $${{\\beta}_{\\text{P}}}$$ scenario could be a candidate for ITER steady state operation.« less

Overview of recent HL-2A experiments

NASA Astrophysics Data System (ADS)

Duan, X. R.; Liu, Yi; Xu, M.; Yan, L. W.; Xu, Y.; Song, X. M.; Dong, J. Q.; Ding, X. T.; Chen, L. Y.; Lu, B.; Liu, D. Q.; Rao, J.; Xuan, W. M.; Yang, Q. W.; Zheng, G. Y.; Zou, X. L.; Liu, Y. Q.; Zhong, W. L.; Zhao, K. J.; Ji, X. Q.; Mao, W. C.; Wang, Q. M.; Li, Q.; Cao, J. Y.; Cao, Z.; Lei, G. J.; Zhang, J. H.; Li, X. D.; Bai, X. Y.; Cheng, J.; Chen, W.; Cui, Z. Y.; Delpech, L.; Diamond, P. H.; Dong, Y. B.; Ekedahl, A.; Hoang, T.; Huang, Y.; Ida, K.; Itoh, K.; Itoh, S.-I.; Isobe, M.; Inagaki, S.; Mazon, D.; Morita, S.; Peysson, Y.; Shi, Z. B.; Wang, X. G.; Xiao, G. L.; Yu, D. L.; Yu, L. M.; Zhang, Y. P.; Zhou, Y.; Cui, C. H.; Feng, B. B.; Huang, M.; Li, Y. G.; Li, B.; Li, G. S.; Li, H. J.; Li, Qing; Peng, J. F.; Wang, Y. Q.; Yuan, B. S.; Liu, Yong; HL-2A Team

2017-10-01

Since the last Fusion Energy Conference, significant progress has been made in the following areas. The first high coupling efficiency low-hybrid current drive (LHCD) with a passive-active multi-junction (PAM) antenna was successfully demonstrated in the H-mode on the HL-2A tokamak. Double critical impurity gradients of electromagnetic turbulence were observed in H-mode plasmas. Various ELM mitigation techniques have been investigated, including supersonic molecular beam injection (SMBI), impurity seeding, resonant magnetic perturbation (RMP) and low-hybrid wave (LHW). The ion internal transport barrier was observed in neutral beam injection (NBI) heated plasmas. Neoclassical tearing modes (NTMs) driven by the transient perturbation of local electron temperature during non-local thermal transport events have been observed, and a new type of non-local transport triggered by the ion fishbone was found. A long-lasting runaway electron plateau was achieved after argon injection and the runaway current was successfully suppressed by SMBI. It was found that low-n Alfvénic ion temperature gradient (AITG) modes can be destabilized in ohmic plasmas, even with weak magnetic shear and low-pressure gradients. For the first time, the synchronization of geodesic acoustic mode (GAM) and magnetic fluctuations was observed in edge plasmas, revealing frequency entrainment and phase lock. The spatiotemporal features of zonal flows were also studied using multi-channel correlation Doppler reflectometers.

Effect of Nb on magnetic and mechanical properties of TbDyFe alloys

NASA Astrophysics Data System (ADS)

Wang, Naijuan; Liu, Yuan; Zhang, Huawei; Chen, Xiang; Li, Yanxiang

2018-03-01

The intrinsic brittleness in giant magnetostrictive material TbDyFe alloy has devastating influence on the machinability and properties of the alloy, thus affecting its applications. The purpose of this paper is to study the mechanical properties of the TbDyFe alloy by alloying with Nb element. The samples (Tb0.3Dy0.7)xFe2xNby (y = 0, 0.01, 0.04, 0.07, 0.1; 3x + y = 1) were melted in an arc melting furnace under high purity argon atmosphere. The microstructure, magnetostrictive properties and mechanical performance of the alloys were studied systematically. The results showed that NbFe2 phases were observed in the alloys with the addition of Nb. Moreover, both the NbFe2 phases and rare earth (RE)-rich phases were increased with the increasing of Nb element. The mechanical properties results revealed that the fracture toughness of the alloy with the addition of Nb enhanced 1.5-5 times of the Nb-free alloy. Both the NbFe2 phase and the RE-rich phase had the ability to prevent crack propagation, so that they can strengthen the REFe2 body. However, NbFe2 phase is a paramagnetic phase, which can reduce the magnetostrictive properties of the alloy by excessive precipitation.

Towards a realistic 3D simulation of the extraction region in ITER NBI relevant ion source

NASA Astrophysics Data System (ADS)

Mochalskyy, S.; Wünderlich, D.; Fantz, U.; Franzen, P.; Minea, T.

2015-03-01

The development of negative ion (NI) sources for ITER is strongly accompanied by modelling activities. The ONIX code addresses the physics of formation and extraction of negative hydrogen ions at caesiated sources as well as the amount of co-extracted electrons. In order to be closer to the experimental conditions the code has been improved. It includes now the bias potential applied to first grid (plasma grid) of the extraction system, and the presence of Cs+ ions in the plasma. The simulation results show that such aspects play an important role for the formation of an ion-ion plasma in the boundary region by reducing the depth of the negative potential well in vicinity to the plasma grid that limits the extraction of the NIs produced at the Cs covered plasma grid surface. The influence of the initial temperature of the surface produced NI and its emission rate on the NI density in the bulk plasma that in turn affects the beam formation region was analysed. The formation of the plasma meniscus, the boundary between the plasma and the beam, was investigated for the extraction potentials of 5 and 10 kV. At the smaller extraction potential the meniscus moves closer to the plasma grid but as in the case of 10 kV the deepest meniscus bend point is still outside of the aperture. Finally, a plasma containing the same amount of NI and electrons (nH- =ne =1017 m-3) , representing good source conditioning, was simulated. It is shown that at such conditions the extracted NI current can reach values of ˜32 mA cm-2 using ITER-relevant extraction potential of 10 kV and ˜19 mA cm-2 at 5 kV. These results are in good agreement with experimental measurements performed at the small scale ITER prototype source at the test facility BATMAN.

Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade

DOE PAGES

Battaglia, D. J.; Boyer, M. D.; Gerhardt, S.; ...

2018-02-20

The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal field (1 T) and plasma current (1.0 - 2.0 MA) in a low aspect ratio geometry (A = 1.6 - 1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes progress in the development of L- and Hmode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supportedmore » the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (BT0 = 0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (tpulse > 1.8s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (Ip). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2 > 1) and stability (βN/βN-nowall > 1) compared to NSTX discharges for Ip ≤ 1 MA. High-performance H-mode scenarios require an L-H transition early in the Ip ramp-up phase in order to obtain low internal inductance (li) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (κ > 2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.« less

Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battaglia, D. J.; Boyer, M. D.; Gerhardt, S.

The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal field (1 T) and plasma current (1.0 - 2.0 MA) in a low aspect ratio geometry (A = 1.6 - 1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes progress in the development of L- and Hmode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supportedmore » the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (BT0 = 0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (tpulse > 1.8s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (Ip). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2 > 1) and stability (βN/βN-nowall > 1) compared to NSTX discharges for Ip ≤ 1 MA. High-performance H-mode scenarios require an L-H transition early in the Ip ramp-up phase in order to obtain low internal inductance (li) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (κ > 2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.« less

Gyrokinetic modeling of impurity peaking in JET H-mode plasmas

NASA Astrophysics Data System (ADS)

Manas, P.; Camenen, Y.; Benkadda, S.; Weisen, H.; Angioni, C.; Casson, F. J.; Giroud, C.; Gelfusa, M.; Maslov, M.

2017-06-01

Quantitative comparisons are presented between gyrokinetic simulations and experimental values of the carbon impurity peaking factor in a database of JET H-modes during the carbon wall era. These plasmas feature strong NBI heating and hence high values of toroidal rotation and corresponding gradient. Furthermore, the carbon profiles present particularly interesting shapes for fusion devices, i.e., hollow in the core and peaked near the edge. Dependencies of the experimental carbon peaking factor ( R / L nC ) on plasma parameters are investigated via multilinear regressions. A marked correlation between R / L nC and the normalised toroidal rotation gradient is observed in the core, which suggests an important role of the rotation in establishing hollow carbon profiles. The carbon peaking factor is then computed with the gyrokinetic code GKW, using a quasi-linear approach, supported by a few non-linear simulations. The comparison of the quasi-linear predictions to the experimental values at mid-radius reveals two main regimes. At low normalised collisionality, ν * , and T e / T i < 1 , the gyrokinetic simulations quantitatively recover experimental carbon density profiles, provided that rotodiffusion is taken into account. In contrast, at higher ν * and T e / T i > 1 , the very hollow experimental carbon density profiles are never predicted by the simulations and the carbon density peaking is systematically over estimated. This points to a possible missing ingredient in this regime.

LETTER: Study of combined NBI and ICRF enhancement of the D-3He fusion yield with a Fokker-Planck code

NASA Astrophysics Data System (ADS)

Azoulay, M.; George, M. A.; Burger, A.; Collins, W. E.; Silberman, E.

A two-dimensional bounce averaged Fokker-Planck code is used to study the fusion yield and the wave absorption by residual hydrogen ions in higher harmonic ICRF heating of D (120 keV) and 3He (80 keV) beams in the JT-60U tokamak. Both for the fourth harmonic resonance of 3He (ω = 4ωc3He(0), which is accompanied by the third harmonic resonance of hydrogen (ω = 3ωcH) at the low field side, and for the third harmonic resonance of 3He (ω = 4ωcD(0) = 3ωc3He(0)) = 2ωcH(0)), a few per cent of hydrogen ions are found to absorb a large fraction of the ICRF power and to degrade the fusion output power. In the latter case, D beam acceleration due to the fourth harmonic resonance in the 3He(D) regime can enhance the fusion yield more effectively. A discussion is given of the effect of D beam acceleration due to the fifth harmonic resonance (ω = 5ωcD) at the high field side in the case of ω = 4ωc3He(0) and of the optimization of the fusion yield in the case of lower electron density and higher electron temperature

Quiescence near the X-point of MAST measured by high speed visible imaging

NASA Astrophysics Data System (ADS)

Walkden, N. R.; Harrison, J.; Silburn, S. A.; Farley, T.; Henderson, S. S.; Kirk, A.; Militello, F.; Thornton, A.; The MAST Team

2017-12-01

Using high speed imaging of the divertor volume, the region close to the X-point in MAST is shown to be quiescent. This is confirmed by three different analysis techniques and the quiescent X-point region (QXR) spans from the separatrix to the \\psiN = 1.02 flux surface. Local reductions to the atomic density and effects associated with the camera viewing geometry are ruled out as causes of the QXR, leaving quiescence in the local plasma conditions as being the most likely cause. The QXR is found to be ubiquitous across a significant operational space in MAST including L-mode and H-mode discharges across maximal ranges of 9.8×1019~m-2 in line integrated density, 0.36 MA in plasma current, 0.11 T in toroidal magnetic field and 3.2 MW in NBI power. When mapped to the divertor target the QXR occupies approximately an e-folding length of the heat-flux profile, containing  ∼60% of the total heat flux to the target, and also shows a tendency towards higher frequency shorter lived fluctuations in the ion-saturation current. This is consistent with short-lived divertor localised filamentary structures observed further down the outer divertor leg in the camera images, and suggests a complex multi-region picture of filamentary transport in the divertor.

Investigation of physical processes limiting plasma density in H-mode on DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maingi, R.; Mahdavi, M.A.; Jernigan, T.C.

1996-12-01

A series of experiments was conducted on the DIII-D tokamak to investigate the physical processes which limit density in high confinement mode (H-mode) discharges. The typical H-mode to low confinement mode (L-mode) transition limit at high density near the empirical Greenwald density limit was avoided by divertor pumping, which reduced divertor neutral pressure and prevented formation of a high density, intense radiation zone (MARFE) near the X-point. It was determined that the density decay time after pellet injection was independent of density relative to the Greenwald limit and increased non-linearly with the plasma current. Magnetohydrodynamic (MHD) activity in pellet-fueled plasmasmore » was observed at all power levels, and often caused unacceptable confinement degradation, except when the neutral beam injected (NBI) power was {le} 3 MW. Formation of MARFEs on closed field lines was avoided with low safety factor (q) operation but was observed at high q, qualitatively consistent with theory. By using pellet fueling and optimizing discharge parameters to avoid each of these limits, an operational space was accessed in which density {approximately} 1.5 {times} Greenwald limit was achieved for 600 ms, and good H-mode confinement was maintained for 300 ms of the density flattop. More significantly, the density was successfully increased to the limit where a central radiative collapse was observed, the most fundamental density limit in tokamaks.« less

A new optical leaf-clip meter for simultaneous non-destructive assessment of leaf chlorophyll and epidermal flavonoids

PubMed Central

Cerovic, Zoran G; Masdoumier, Guillaume; Ghozlen, NaÏma Ben; Latouche, Gwendal

2012-01-01

We have characterized a new commercial chlorophyll (Chl) and flavonoid (Flav) meter called Dualex 4 Scientific (Dx4). We compared this device to two other Chl meters, the SPAD-502 and the CCM-200. In addition, Dx4 was compared to the leaf-clip Dualex 3 that measures only epidermal Flav. Dx4 is factory-calibrated to provide a linear response to increasing leaf Chl content in units of µg cm–2, as opposed to both SPAD-502 and CCM-200 that have a non-linear response to leaf Chl content. Our comparative calibration by Chl extraction confirmed these responses. It seems that the linear response of Dx4 derives from the use of 710 nm as the sampling wavelength for transmittance. The major advantage of Dx4 is its simultaneous assessment of Chl and Flav on the same leaf spot. This allows the generation of the nitrogen balance index (NBI) used for crop surveys and nitrogen nutrition management. The Dx4 leaf clip, that incorporates a GPS receiver, can be useful for non-destructive estimation of leaf Chl and Flav contents for ecophysiological research and ground truthing of remote sensing of vegetation. In this work, we also propose a consensus equation for the transformation of SPAD units into leaf Chl content, for general use. PMID:22568678

A new optical leaf-clip meter for simultaneous non-destructive assessment of leaf chlorophyll and epidermal flavonoids.

PubMed

Cerovic, Zoran G; Masdoumier, Guillaume; Ghozlen, Naïma Ben; Latouche, Gwendal

2012-11-01

We have characterized a new commercial chlorophyll (Chl) and flavonoid (Flav) meter called Dualex 4 Scientific (Dx4). We compared this device to two other Chl meters, the SPAD-502 and the CCM-200. In addition, Dx4 was compared to the leaf-clip Dualex 3 that measures only epidermal Flav. Dx4 is factory-calibrated to provide a linear response to increasing leaf Chl content in units of µg cm(-2), as opposed to both SPAD-502 and CCM-200 that have a non-linear response to leaf Chl content. Our comparative calibration by Chl extraction confirmed these responses. It seems that the linear response of Dx4 derives from the use of 710 nm as the sampling wavelength for transmittance. The major advantage of Dx4 is its simultaneous assessment of Chl and Flav on the same leaf spot. This allows the generation of the nitrogen balance index (NBI) used for crop surveys and nitrogen nutrition management. The Dx4 leaf clip, that incorporates a GPS receiver, can be useful for non-destructive estimation of leaf Chl and Flav contents for ecophysiological research and ground truthing of remote sensing of vegetation. In this work, we also propose a consensus equation for the transformation of SPAD units into leaf Chl content, for general use. Copyright © Physiologia Plantarum 2012.

S-(N, N-diethylcarbamoyl)glutathione (carbamathione), a disulfiram metabolite and its effect on nucleus accumbens and prefrontal cortex dopamine, GABA, and glutamate: A microdialysis study

PubMed Central

Faiman, Morris D.; Kaul, Swetha; Latif, Shaheen A.; Williams, Todd D.; Lunte, Craig E.

2015-01-01

Disulfiram (DSF), used for the treatment of alcohol use disorders (AUDs) for over six decades, most recently has shown promise for treating cocaine dependence. Although DSF’s mechanism of action in alcohol abuse is due to the inhibition of liver mitochondrial aldehyde dehydrogenase (ALDH2), its mechanism of action in the treatment of cocaine dependence is unknown. DSF is a pro-drug, forming a number of metabolites each with discrete pharmacological actions. One metabolite formed during DSF bioactivation is S-(N, N-diethylcarbamoyl) glutathione (carbamathione) (carb). We previously showed that carb affects glutamate binding. In the present studies, we employed microdialysis techniques to investigate the effect of carb administration on dopamine (DA), GABA, and glutamate (Glu) in the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC), two brain regions implicated in substance abuse dependence. The effect of DSF on DA, GABA, and Glu in the NAc also was determined. Both studies were carried out in male rats. Carb (20, 50, 200 mg/kg i v) in a dose-dependent manner increased DA, decreased GABA, and had a biphasic effect on Glu, first increasing and then decreasing Glu in both the NAc and mPFC. These changes all occurred concurrently. After carb administration, NAc and mPFC carb, as well as carb in plasma, were rapidly eliminated with a half-life for each approximately 4 min, while the changes in DA, GABA, and GLu in the NAc and mPFC persisted for approximately two hours. The maximal increase in carb (Cmax) in the NAc and mPFC after carb administration was dose-dependent, as was the area under the curve (AUC). DSF (200 mg/kg i p) also increased DA, decreased GABA, and had a biphasic effect on Glu in the NAc similar to that observed in the NAc after carb administration. When the cytochrome P450 inhibitor N-benzylimidazole (NBI) (20 mg/kg i p) was administered before DSF dosing, no carb could be detected in the NAc and plasma and also no changes in NAc DA, GABA, and GLu occurred. Changes in these neurotransmitters occurred only if carb was formed from DSF. When NBI was administered prior to dosing with carb, the increase in DA, decrease in GABA, and biphasic effect on GLu was similar to that seen after dosing with carb only. The i p or i v administration of carb showed similar changes in DA, GABA, and GLu, except the time to reach Cmax for DA as well as the changes in GABA, and GLu after i p administration occurred later. The elimination half-life of carb and the area under the curve (AUC) were similar after both routes of administration. It is concluded that carb must be formed from DSF before any changes in DA, GABA, and GLu in the NAc and mPFC are observed. DSF and carb, when administered to rats, co-release DA, GABA, and GLu. Carb, once formed can cross the blood brain barrier and enter the brain. Although inhibition of liver ALDH2 is the accepted mechanism for DSF’s action in treating AUDs, the concurrent changes in DA, GABA, and GLu in the NAc and mPFC after DSF administration suggest that changes in these neurotransmitters as a potential mechanism of action not only for AUDs, but also for cocaine dependence cannot be excluded. PMID:23891816

Efficacy of Valbenazine (NBI-98854) in Treating Subjects with Tardive Dyskinesia and Schizophrenia or Schizoaffective Disorder

PubMed Central

Kane, John M.; Correll, Christoph U.; Liang, Grace S.; Burke, Joshua; O’Brien, Christopher F.

2017-01-01

Background Valbenazine (VBZ, NBI-98854) is a novel vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia (TD). The KINECT 3 study (NCT02274558) evaluated the effects of VBZ on TD in subjects with schizophrenia/schizoaffective disorder (SCHZ) or mood disorder (mood disorder presented separately) who received up to 48 weeks of treatment. Methods KINECT 3 included: 6-week, double-blind, placebo (PBO)-controlled (DBPC) period (205 completers); 42-week VBZ extension (VE) period (124 completers): 4-week washout period (121 completers). Subjects entering the DBPC were randomized 1:1:1 to once-daily VBZ 80 mg, VBZ 40 mg, or PBO; stable concomitant antipsychotic medication regimens were allowed. Subjects completing the DBPC and entering the VE period were re-randomized (blinded) 1:1 from PBO to VBZ (80 or 40 mg) or continued VBZ treatment at the same dose. Efficacy assessments included: mean changes from baseline in Abnormal Involuntary Movement Scale (AIMS) total score (items 1–7); mean Clinical Global Impression of Change (CGI-TD) scores; AIMS responders (subjects with ≥50% score reduction from baseline): and CGI-TD responders (subjects with score ≤2 [“much improved” or “very much improved”]). Treatment effect sizes (Cohen’s d) and numbers needed to treat (NNTs) were analyzed for DBPC outcomes. Results Efficacy analyses were conducted in 148 subjects (DBPC) and 125 subjects (VE) with SCHZ. At Week 6 (end of DBPC), AIMS mean score improvements were greater in the VBZ groups (in a dose-related pattern) than in the PBO group (80 mg, -2.9, d = 0.88; 40 mg, -1.6, d = 0.52; PBO, +0.3). AIMS score changes at Week 48 (end of VE) showed continued TD improvement during long-term VBZ treatment (80 mg, -4.2; 40 mg, -2.5). By Week 52 (end of washout), AIMS scores were returning toward baseline levels, indicating re-emergence of TD. CGI-TD mean scores were as follows: Week 6 (80 mg, 3.0, d = 0.11; 40 mg, 2.9, d = 0.23; PBO, 3.2), Week 48 (80 mg, 2.2; 40 mg, 2.4), Week 52 (80 mg, 3.4; 40 mg, 3.3). AIMS responder rates (≥50% score reduction) were greater with VBZ than with PBO at Week 6 (80 mg, 40.9%, NNT = 4; 40 mg, 26.2%, NNT = 6; PBO, 9.3%), were increased at Week 48 (80 mg, 50.0%; 40 mg, 26.2%), and decreased after VBZ washout (80 mg, 21.6%; 40 mg, 9.5%). CGI-TD responder rates followed a similar pattern: Week 6 (80 mg, 29.5%, NNT = 17; 40 mg, 33.3%, NNT = 10; PBO, 23.3%), Week 48 (80 mg, 73.7%; 40 mg, 58.1%), Week 52 (80 mg, 29.7%; 40 mg, 33.3%). Conclusion Sustained TD improvements were found in subjects with SCHZ who received up to 48 weeks of VBZ, with TD reverting toward baseline when assessed 4 weeks after treatment withdrawal. Together with results from mood disorder subjects and the long-term safety profile (presented separately), these results indicate that long-term VBZ can be beneficial for managing TD regardless of psychiatric diagnosis category. PMID:28839342

Efficacy of Valbenazine (NBI-98854) in Treating Subjects with Tardive Dyskinesia and Mood Disorder.

PubMed

Correll, Christoph U; Josiassen, Richard C; Liang, Grace S; Burke, Joshua; O'Brien, Christopher F

2017-08-01

Valbenazine (VBZ, NBI-98854) is a novel vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia (TD). The KINECT 3 study (NCT02274558) evaluated the effects of VBZ on TD in subjects with mood disorder or schizophrenia/schizoaffective disorder (SCHZ, presented separately) who received up to 48 weeks of treatment. KINECT 3 included: 6-week, double-blind, placebo (PBO)-controlled (DBPC) period (205 completers); 42-week VBZ extension (VE) period (124 completers); 4-week washout period (121 completers). Subjects entering the DBPC were randomized 1:1:1 to once-daily VBZ 80 mg, VBZ 40 mg, or PBO; stable concomitant antipsychotic medication regimens were allowed. Subjects completing the DBPC and entering the VE period were re-randomized (blinded) from PBO to VBZ (80 or 40 mg) or continued VBZ treatment at the same dose. Efficacy assessments included: mean changes from baseline in Abnormal Involuntary Movement Scale (AIMS) total score (items 1-7); mean Clinical Global Impression of Change (CGI-TD) scores; AIMS responders (subjects with ≥50% score reduction from baseline); and CGI-TD responders (subjects with score ≤2 ["much improved" or "very much improved"]). Treatment effect sizes (Cohen's d) and numbers needed to treat (NNTs) were analyzed for DBPC outcomes. Efficacy analyses were conducted in 77 subjects (DBPC) and 73 subjects (VE) with a mood disorder. At Week 6 (end of DBPC), AIMS mean score improvements were greater in the VBZ groups (in a dose-related pattern) than in the PBO group (80 mg, -3.6, d = 0.94; 40 mg, -2.4, d = 0.55; PBO, -0.7). AIMS mean score changes at Week 48 (end of VE) showed continued TD improvement during long-term VBZ treatment (80 mg, -5.8; 40 mg, -4.2). By Week 52 (end of washout), AIMS mean scores in both dose groups were returning toward baseline levels, indicating re-emergence of TD. CGI-TD scores showed a similar pattern: Week 6 (80 mg, 2.7, d = 0.64; 40 mg, 2.9, d = 0.39; PBO, 3.2), Week 48 (80 mg, 2.0; 40 mg, 2.2), Week 52 (80 mg, 3.6; 40 mg, 2.8). AIMS responder rates (≥50% score reduction) were greater with VBZ vs PBO at Week 6 (80 mg, 38.5%, NNT = 4; 40 mg, 19.0%, NNT = 9; PBO, 7.7%), were increased at Week 48 (80 mg, 56.0%; 40 mg, 33.3%), and lower after VBZ washout (Week 52 80 mg, 16.7%; 40 mg, 27.8%). CGI-TD responder rates followed a similar pattern: Week 6 (80 mg, 34.6%, NNT = 6; 40 mg, 28.6%, NNT = 8; PBO, 15.4%), Week 48 (80 mg, 80.0%; 40 mg, 61.1%), Week 52 (80 mg, 25.0%; 40 mg, 44.4%). Sustained TD improvements were found in subjects with a mood disorder who received up to 48 weeks of VBZ, with TD reverting toward baseline severity when assessed 4 weeks after treatment withdrawal. Together with results from SCHZ subjects and the long-term safety profile (presented separately), these results indicate that long-term VBZ can be beneficial for managing TD regardless of psychiatric diagnosis.

Efficacy of Valbenazine (NBI-98854) in Treating Subjects with Tardive Dyskinesia and Mood Disorder

PubMed Central

Correll, Christoph U.; Josiassen, Richard C.; Liang, Grace S.; Burke, Joshua; O’Brien, Christopher F.

2017-01-01

Background Valbenazine (VBZ, NBI-98854) is a novel vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia (TD). The KINECT 3 study (NCT02274558) evaluated the effects of VBZ on TD in subjects with mood disorder or schizophrenia/schizoaffective disorder (SCHZ, presented separately) who received up to 48 weeks of treatment. Methods KINECT 3 included: 6-week, double-blind, placebo (PBO)-controlled (DBPC) period (205 completers); 42-week VBZ extension (VE) period (124 completers); 4-week washout period (121 completers). Subjects entering the DBPC were randomized 1:1:1 to once-daily VBZ 80 mg, VBZ 40 mg, or PBO; stable concomitant antipsychotic medication regimens were allowed. Subjects completing the DBPC and entering the VE period were re-randomized (blinded) from PBO to VBZ (80 or 40 mg) or continued VBZ treatment at the same dose. Efficacy assessments included: mean changes from baseline in Abnormal Involuntary Movement Scale (AIMS) total score (items 1–7); mean Clinical Global Impression of Change (CGI-TD) scores; AIMS responders (subjects with ≥50% score reduction from baseline); and CGI-TD responders (subjects with score ≤2 [“much improved” or “very much improved”]). Treatment effect sizes (Cohen’s d) and numbers needed to treat (NNTs) were analyzed for DBPC outcomes. Results Efficacy analyses were conducted in 77 subjects (DBPC) and 73 subjects (VE) with a mood disorder. At Week 6 (end of DBPC), AIMS mean score improvements were greater in the VBZ groups (in a dose-related pattern) than in the PBO group (80 mg, -3.6, d = 0.94; 40 mg, -2.4, d = 0.55; PBO, -0.7). AIMS mean score changes at Week 48 (end of VE) showed continued TD improvement during long-term VBZ treatment (80 mg, -5.8; 40 mg, -4.2). By Week 52 (end of washout), AIMS mean scores in both dose groups were returning toward baseline levels, indicating re-emergence of TD. CGI-TD scores showed a similar pattern: Week 6 (80 mg, 2.7, d = 0.64; 40 mg, 2.9, d = 0.39; PBO, 3.2), Week 48 (80 mg, 2.0; 40 mg, 2.2), Week 52 (80 mg, 3.6; 40 mg, 2.8). AIMS responder rates (≥50% score reduction) were greater with VBZ vs PBO at Week 6 (80 mg, 38.5%, NNT = 4; 40 mg, 19.0%, NNT = 9; PBO, 7.7%), were increased at Week 48 (80 mg, 56.0%; 40 mg, 33.3%), and lower after VBZ washout (Week 52 80 mg, 16.7%; 40 mg, 27.8%). CGI-TD responder rates followed a similar pattern: Week 6 (80 mg, 34.6%, NNT = 6; 40 mg, 28.6%, NNT = 8; PBO, 15.4%), Week 48 (80 mg, 80.0%; 40 mg, 61.1%), Week 52 (80 mg, 25.0%; 40 mg, 44.4%). Conclusion Sustained TD improvements were found in subjects with a mood disorder who received up to 48 weeks of VBZ, with TD reverting toward baseline severity when assessed 4 weeks after treatment withdrawal. Together with results from SCHZ subjects and the long-term safety profile (presented separately), these results indicate that long-term VBZ can be beneficial for managing TD regardless of psychiatric diagnosis. PMID:28839340

Efficacy of Valbenazine (NBI-98854) in Treating Subjects with Tardive Dyskinesia and Schizophrenia or Schizoaffective Disorder.

PubMed

Kane, John M; Correll, Christoph U; Liang, Grace S; Burke, Joshua; O'Brien, Christopher F

2017-08-01

Valbenazine (VBZ, NBI-98854) is a novel vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia (TD). The KINECT 3 study (NCT02274558) evaluated the effects of VBZ on TD in subjects with schizophrenia/schizoaffective disorder (SCHZ) or mood disorder (mood disorder presented separately) who received up to 48 weeks of treatment. KINECT 3 included: 6-week, double-blind, placebo (PBO)-controlled (DBPC) period (205 completers); 42-week VBZ extension (VE) period (124 completers): 4-week washout period (121 completers). Subjects entering the DBPC were randomized 1:1:1 to once-daily VBZ 80 mg, VBZ 40 mg, or PBO; stable concomitant antipsychotic medication regimens were allowed. Subjects completing the DBPC and entering the VE period were re-randomized (blinded) 1:1 from PBO to VBZ (80 or 40 mg) or continued VBZ treatment at the same dose. Efficacy assessments included: mean changes from baseline in Abnormal Involuntary Movement Scale (AIMS) total score (items 1-7); mean Clinical Global Impression of Change (CGI-TD) scores; AIMS responders (subjects with ≥50% score reduction from baseline): and CGI-TD responders (subjects with score ≤2 ["much improved" or "very much improved"]). Treatment effect sizes (Cohen's d) and numbers needed to treat (NNTs) were analyzed for DBPC outcomes. Efficacy analyses were conducted in 148 subjects (DBPC) and 125 subjects (VE) with SCHZ. At Week 6 (end of DBPC), AIMS mean score improvements were greater in the VBZ groups (in a dose-related pattern) than in the PBO group (80 mg, -2.9, d = 0.88; 40 mg, -1.6, d = 0.52; PBO, +0.3). AIMS score changes at Week 48 (end of VE) showed continued TD improvement during long-term VBZ treatment (80 mg, -4.2; 40 mg, -2.5). By Week 52 (end of washout), AIMS scores were returning toward baseline levels, indicating re-emergence of TD. CGI-TD mean scores were as follows: Week 6 (80 mg, 3.0, d = 0.11; 40 mg, 2.9, d = 0.23; PBO, 3.2), Week 48 (80 mg, 2.2; 40 mg, 2.4), Week 52 (80 mg, 3.4; 40 mg, 3.3). AIMS responder rates (≥50% score reduction) were greater with VBZ than with PBO at Week 6 (80 mg, 40.9%, NNT = 4; 40 mg, 26.2%, NNT = 6; PBO, 9.3%), were increased at Week 48 (80 mg, 50.0%; 40 mg, 26.2%), and decreased after VBZ washout (80 mg, 21.6%; 40 mg, 9.5%). CGI-TD responder rates followed a similar pattern: Week 6 (80 mg, 29.5%, NNT = 17; 40 mg, 33.3%, NNT = 10; PBO, 23.3%), Week 48 (80 mg, 73.7%; 40 mg, 58.1%), Week 52 (80 mg, 29.7%; 40 mg, 33.3%). Sustained TD improvements were found in subjects with SCHZ who received up to 48 weeks of VBZ, with TD reverting toward baseline when assessed 4 weeks after treatment withdrawal. Together with results from mood disorder subjects and the long-term safety profile (presented separately), these results indicate that long-term VBZ can be beneficial for managing TD regardless of psychiatric diagnosis category.

Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade

NASA Astrophysics Data System (ADS)

Battaglia, D. J.; Boyer, M. D.; Gerhardt, S.; Mueller, D.; Myers, C. E.; Guttenfelder, W.; Menard, J. E.; Sabbagh, S. A.; Scotti, F.; Bedoya, F.; Bell, R. E.; Berkery, J. W.; Diallo, A.; Ferraro, N.; Kaye, S. M.; Jaworski, M. A.; LeBlanc, B. P.; Ono, M.; Park, J.-K.; Podesta, M.; Raman, R.; Soukhanovskii, V.; NSTX-U Research, the; Operations; Engineering Team

2018-04-01

The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal fields (1 T) and plasma currents (1.0-2.0 MA) in a low aspect ratio geometry (A  =  1.6-1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes the progress in the development of L- and H-mode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supported the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (B T0  =  0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (t pulse  >  1.8 s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (I p). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2  >  1) and stability (β N/β N-nowall  >  1) compared to NSTX discharges for I p  ⩽  1 MA. High-performance H-mode scenarios require an L-H transition early in the I p ramp-up phase in order to obtain low internal inductance (l i) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (κ  >  2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.

Turbulent particle transport as a function of toroidal rotation in DIII-D H-mode plasmas

DOE PAGES

Wang, Xin; Mordijck, Saskia; Zeng, Lei; ...

2016-03-01

In this paper we show how changes in toroidal rotation, by controlling the injected torque, affect particle transport and confinement. The toroidal rotation is altered using the co- and counter neutral beam injection (NBI) in low collisionality H-mode plasmas on DIII-D with dominant electron cyclotron heating (ECH). We find that there is no correlation between the toroidal rotation shear and the inverse density gradient, which is observed on AUG whenmore » $${{T}_{\\text{e}}}/{{T}_{\\text{i}}}$$ is varied using ECH (Angioni et al 2011 Phys. Rev. Lett. 107 215003). In DIII-D, we find that in a discharge with balanced torque injection, the $$E\\times B$$ shear is smaller than the linear gyrokinetic growth rate for small $${{k}_{\\theta}}{{\\rho}_{s}}$$ for $$\\rho =0.6$$ –0.85. This results in lower particle confinement. In the co- and counter- injected discharges the $$E\\times B$$ shear is larger or close to the linear growth rate at the plasma edge and both configurations have higher particle confinement. In order to measure particle transport, we use a small periodic perturbative gas puff. This gas puff perturbs the density profiles and allows us to extract the perturbed diffusion and inward pinch coefficients. We observe a strong increase in the inward particle pinch in the counter-torque injected plasma. Lastly, the calculated quasi-linear particle flux, nor the linear growth rates using TGLF agree with experimental observations.« less

A provenance study of iron archaeological artefacts by Inductively Coupled Plasma-Mass Spectrometry multi-elemental analysis

NASA Astrophysics Data System (ADS)

Desaulty, Anne-Marie; Mariet, Clarisse; Dillmann, Philippe; Joron, Jean Louis; Fluzin, Philippe

2008-11-01

Raw materials and wastes (i.e. ore, slag and laitier) from ironmaking archaeological sites have been analyzed in order to understand the behavior of the trace elements in the ancient ironmaking processes and to find the significant-most elements to characterize an iron making region. The ICP-MS (Inductively Coupled Plasma Mass Spectrometry) appears to be an excellent technique for this type of studies. The comparison between the ICP-MS results obtained with the Standard Addition method and the INAA (Instrumental Neutron Activation Analyses) results proved that Sc, Co, (Ni), Rb, Cs, Ba, La, Ce, Sm, Eu, Yb, Hf, Th, U contents in the ores, slag and laitiers, and Co and Ni contents in the cast iron can be successfully determined by ICP-MS after wet acid digestion (low detection limits, good sensitivity and precision). By using significant trace element pairs (Yb/Ce, Ce/Th, La/Sc, U/Th, Nb/Y) present in the ores, laitiers and slag, it is possible to discriminate different French ironmaking regions as the Pays de Bray, Lorraine and Pays d'Ouche. These results open the way to further studies on the provenance of iron objects. The comparison between the ICP-MS results obtained with the Standard Calibration Curves method and the INAA results shows that matrices rich in iron, affect the ICP-MS analyses by suppressing the analytes signal. Further studies are necessary to improve understanding matrix effects.

Studies of short-range tungsten migration in DIII-D divertor

NASA Astrophysics Data System (ADS)

Rudakov, D. L.; Stangeby, P. C.; Elder, J. D.; Ding, R.; Abrams, T.; Unterberg, E. A.; Briesemeister, A.; Donovan, D.; McLean, A. G.; Guo, H. Y.; Thomas, D. M.; Hinson, E.; Wampler, W. R.; Watkins, J. G.

2016-10-01

Two toroidal rings of 5 cm wide W-coated TZM inserts were installed in the lower divertor of DIII-D. Migration of W on the graphite tile surfaces 1-6 cm radially outwards from the outermost ring was studied in a series of 23 reproducible lower single null L-mode discharges with the Outer Strike Point (OSP) placed on the ring. The discharges used 3.2 MW of NBI heating power; plasma density and electron temperature at the OSP were about 1x1020m-3 and 30 eV. W gross erosion rates were measured via monitoring 400.9 nm WI line and applying S/XB coefficient. W deposition was measured on a graphite DiMES sample used as a divertor collector probe. The sample featured two 1 mm wide radial inserts; one was exposed for the whole experiment, the other was exchanged every 4-8 plasma discharges. Measurements of the areal density of W on the inserts by post-mortem RBS analysis show that W deposition is largest in the area of net carbon deposition, possibly due to W re-erosion suppression by C deposits. Measured W coverage in the area of net C erosion is comparable to ERO modeling predictions. Supported by US DOE under DE-FG02-07ER54917, DE-AC04-94AL85000, DE-AC05-00OR22725, DE-AC52-07NA27344, DE-FC02-04ER54698.

Divertor-localized fluctuations in NSTX-U L-mode discharges

NASA Astrophysics Data System (ADS)

Scotti, Filippo; Soukhanovskii, V. A.; Zweben, S.; Myra, J.; Baver, D.; Sabbagh, S. A.

2017-10-01

The 3-D structure of divertor turbulence is characterized in NSTX-U by means of fast camera imaging. Edge and divertor turbulence can be important in determining the heat flux width in fusion devices. Field-aligned filaments are found on the divertor legs via imaging of C III and D- α emission in NBI-heated diverted L-mode discharges, similar to observations in Alcator C-Mod and MAST. These flute-like fluctuations of up to 10-20% in RMS/mean are radially localized around the separatrix and limited to the region below the X-point. Poloidal and parallel correlation lengths are a few cm (10-50ρi) and several meters, respectively. For the outer leg filaments, poloidal correlation lengths decrease along the leg away from the strike point and typical effective toroidal mode numbers are in the range of 10-20. Opposite toroidal rotation is observed for inner (co-current rotation) and outer leg (counter-current rotation) filaments with apparent poloidal propagation of 1 km/s. The poloidal motion of outer leg filaments is opposite to the one typically observed for NSTX upstream blobs in the scrape-off layer. The shape, dynamics and absence of correlation with upstream turbulence suggest that these fluctuations are generated and localized in the divertor region. Supported by US DOE DE-AC52-07NA27344, DE-AC02-09CH11466, DE-FG02- 02ER54678, DE-FG02-99ER54524.

High-beta spherical tokamak startup in TS-4 merging experiment by use of toroidal field ramp-up

NASA Astrophysics Data System (ADS)

Kaminou, Yasuhiro; , Toru, II; Kato, Joji; Inomoto, Michiaki; Ono, Yasushi; TS Group Team; National InstituteFusion Science Collaboration

2014-10-01

We demonstrated the formation method of an ultrahigh-beta spherical tokamak by use of a field-reversed configuration and a spheromak in TS-4 device (R ~ 0.5 m, A ~ 1.5, Ip ~ 30-100 kA, B ~ 100 mT). This method is composed of the following steps: 1. Two spheromaks are merged together and a high-beta spheromak or FRC is formed by reconnection heating. 2. External toroidal magnetic field is added (current rising time ~50 μs), and spherical tokamak-like configuration is formed. In this way, the ultrahigh-beta ST is formed. The ultrahigh-beta ST formed by FRC has a diamagnetic toroidal field, and it presumed to be in a second-stable state for ballooning stability, and the one formed by spheromak has a weak paramagnetic toroidal magnetic field, while a spheormak has a strong paramagnetic toroidal magnetic field. This diamagnetic current derives from inductive electric field by ramping up the external toroidal magnetic field, and the diamagnetic current sustains high thermal pressure of the ultrahigh-beta spherical tokamak. And the beta of the ultrahigh-beta ST formed by FRC reaches about 50%. To sustain the high-beta state, 0.6 MW neutral beam injection and center solenoid coils are installed to the TS-4 device. In the poster, we report the experimental results of ultrahigh-beta spherical tokamak startup and sustainment by NBI and CS current driving experiment.

Advances in the high bootstrap fraction regime on DIII-D towards the Q  =  5 mission of ITER steady state

NASA Astrophysics Data System (ADS)

Qian, J. P.; Garofalo, A. M.; Gong, X. Z.; Ren, Q. L.; Ding, S. Y.; Solomon, W. M.; Xu, G. S.; Grierson, B. A.; Guo, W. F.; Holcomb, C. T.; McClenaghan, J.; McKee, G. R.; Pan, C. K.; Huang, J.; Staebler, G. M.; Wan, B. N.

2017-05-01

Recent EAST/DIII-D joint experiments on the high poloidal beta {β\\text{P}} regime in DIII-D have extended operation with internal transport barriers (ITBs) and excellent energy confinement (H 98y2 ~ 1.6) to higher plasma current, for lower q 95  ⩽  7.0, and more balanced neutral beam injection (NBI) (torque injection  <  2 Nm), for lower plasma rotation than previous results (Garofalo et al, IAEA 2014, Gong et al 2014 IAEA Int. Conf. on Fusion Energy). Transport analysis and experimental measurements at low toroidal rotation suggest that the E  ×  B shear effect is not key to the ITB formation in these high {β\\text{P}} discharges. Experiments and TGLF modeling show that the Shafranov shift has a key stabilizing effect on turbulence. Extrapolation of the DIII-D results using a 0D model shows that with the improved confinement, the high bootstrap fraction regime could achieve fusion gain Q  =  5 in ITER at {β\\text{N}} ~ 2.9 and q 95 ~ 7. With the optimization of q(0), the required improved confinement is achievable when using 1.5D TGLF-SAT1 for transport simulations. Results reported in this paper suggest that the DIII-D high {β\\text{P}} scenario could be a candidate for ITER steady state operation.

Lower hybrid current drive in experiments for transport barriers at high βN of JET (Joint European Torus)

NASA Astrophysics Data System (ADS)

Cesario, R. C.; Castaldo, C.; Fonseca, A.; De Angelis, R.; Parail, V.; Smeulders, P.; Beurskens, M.; Brix, M.; Calabrò, G.; De Vries, P.; Mailloux, J.; Pericoli, V.; Ravera, G.; Zagorski, R.

2007-09-01

LHCD has been used in JET experiments aimed at producing internal transport barriers (ITBs) in highly triangular plasmas (δ≈0.4) at high βN (up to 3) for steady-state application. The LHCD is a potentially valuable tool for (i) modifying the target q-profile, which can help avoid deleterious MHD modes and favour the formation of ITBs, and (ii) contributing to the non-inductive current drive required to prolong such plasma regimes. The q-profile evolution has been simulated during the current ramp-up phase for such a discharge (B0 = 2.3 T, IP = 1.5 MA) where 2 MW of LHCD has been coupled. The JETTO code was used taking measured plasma profiles, and the LHCD profile modeled by the LHstar code. The results are in agreement with MSE measurements and indicate the importance of the elevated electron temperature due to LHCD, as well as the driven current. During main heating with 18 MW of NBI and 3 MW of ICRH the bootstrap current density at the edge also becomes large, consistently with the observed reduction of the local turbulence and of the MHD activity. JETTO modelling suggests that the bootstrap current can reduce the magnetic shear (sh) at large radius, potentially affecting the MHD stability and turbulence behaviour in this region. Keywords: lower hybrid current drive (LHCD), bootstrap current, q (safety factor) and shear (sh) profile evolutions.

Overview of recent and current research on the TCV tokamak

NASA Astrophysics Data System (ADS)

S. Codathe TCV Team

2013-10-01

Through a diverse research programme, the Tokamak à Configuration Variable (TCV) addresses physics issues and develops tools for ITER and for the longer term goals of nuclear fusion, relying especially on its extreme plasma shaping and electron cyclotron resonance heating (ECRH) launching flexibility and preparing for an ECRH and NBI power upgrade. Localized edge heating was unexpectedly found to decrease the period and relative energy loss of edge localized modes (ELMs). Successful ELM pacing has been demonstrated by following individual ELM detection with an ECRH power cut before turning the power back up to trigger the next ELM, the duration of the cut determining the ELM period. Negative triangularity was also seen to reduce the ELM energy release. H-mode studies have focused on the L-H threshold dependence on the main ion species and on the divertor leg length. Both L- and H-modes have been explored in the snowflake configuration with emphasis on edge measurements, revealing that the heat flux to the strike points on the secondary separatrix increases as the X-points approach each other, well before they coalesce. In L-mode, a systematic scan of the auxiliary power deposition profile, with no effect on confinement, has ruled it out as the cause of confinement degradation. An ECRH power absorption observer based on transmitted stray radiation was validated for eventual polarization control. A new profile control methodology was introduced, relying on real-time modelling to supplement diagnostic information; the RAPTOR current transport code in particular has been employed for joint control of the internal inductance and central temperature. An internal inductance controller using the ohmic transformer has also been demonstrated. Fundamental investigations of neoclassical tearing mode (NTM) seed island formation by sawtooth crashes and of NTM destabilization in the absence of a sawtooth trigger were carried out. Both stabilizing and destabilizing agents (electron cyclotron current drive on or inside the q = 1 surface, respectively) were used to pace sawtooth oscillations, permitting precise control of their period. Locking of the sawtooth period to a pre-defined ECRH modulation period was also demonstrated. Sawtooth control has permitted nearly failsafe NTM prevention when combined with backup NTM stabilization by ECRH.

Uncertainties in the production of p nuclides in thermonuclear supernovae determined by Monte Carlo variations

NASA Astrophysics Data System (ADS)

Nishimura, N.; Rauscher, T.; Hirschi, R.; Murphy, A. St J.; Cescutti, G.; Travaglio, C.

2018-03-01

Thermonuclear supernovae originating from the explosion of a white dwarf accreting mass from a companion star have been suggested as a site for the production of p nuclides. Such nuclei are produced during the explosion, in layers enriched with seed nuclei coming from prior strong s processing. These seeds are transformed into proton-richer isotopes mainly by photodisintegration reactions. Several thousand trajectories from a 2D explosion model were used in a Monte Carlo approach. Temperature-dependent uncertainties were assigned individually to thousands of rates varied simultaneously in post-processing in an extended nuclear reaction network. The uncertainties in the final nuclear abundances originating from uncertainties in the astrophysical reaction rates were determined. In addition to the 35 classical p nuclides, abundance uncertainties were also determined for the radioactive nuclides 92Nb, 97, 98Tc, 146Sm, and for the abundance ratios Y(92Mo)/Y(94Mo), Y(92Nb)/Y(92Mo), Y(97Tc)/Y(98Ru), Y(98Tc)/Y(98Ru), and Y(146Sm)/Y(144Sm), important for Galactic Chemical Evolution studies. Uncertainties found were generally lower than a factor of 2, although most nucleosynthesis flows mainly involve predicted rates with larger uncertainties. The main contribution to the total uncertainties comes from a group of trajectories with high peak density originating from the interior of the exploding white dwarf. The distinction between low-density and high-density trajectories allows more general conclusions to be drawn, also applicable to other simulations of white dwarf explosions.

Development of a plasma generator for a long pulse ion source for neutral beam injectors.

PubMed

Watanabe, K; Dairaku, M; Tobari, H; Kashiwagi, M; Inoue, T; Hanada, M; Jeong, S H; Chang, D H; Kim, T S; Kim, B R; Seo, C S; Jin, J T; Lee, K W; In, S R; Oh, B H; Kim, J; Bae, Y S

2011-06-01

A plasma generator for a long pulse H(+)/D(+) ion source has been developed. The plasma generator was designed to produce 65 A H(+)/D(+) beams at an energy of 120 keV from an ion extraction area of 12 cm in width and 45 cm in length. Configuration of the plasma generator is a multi-cusp bucket type with SmCo permanent magnets. Dimension of a plasma chamber is 25 cm in width, 59 cm in length, and 32.5 cm in depth. The plasma generator was designed and fabricated at Japan Atomic Energy Agency. Source plasma generation and beam extraction tests for hydrogen coupling with an accelerator of the KSTAR ion source have been performed at the KSTAR neutral beam test stand under the agreement of Japan-Korea collaborative experiment. Spatial uniformity of the source plasma at the extraction region was measured using Langmuir probes and ±7% of the deviation from an averaged ion saturation current density was obtained. A long pulse test of the plasma generation up to 200 s with an arc discharge power of 70 kW has been successfully demonstrated. The arc discharge power satisfies the requirement of the beam production for the KSTAR NBI. A 70 keV, 41 A, 5 s hydrogen ion beam has been extracted with a high arc efficiency of 0.9 -1.1 A/kW at a beam extraction experiment. A deuteron yield of 77% was measured even at a low beam current density of 73 mA/cm(2). © 2011 American Institute of Physics

Drying characteristic, enzyme inactivation and browning pigmentation kinetics of controlled humidity-convective drying of banana slices

NASA Astrophysics Data System (ADS)

Sarpong, Frederick; Yu, Xiaojie; Zhou, Cunshan; Oteng-Darko, Patricia; Amenorfe, Leticia Peace; Wu, Bengang; Bai, Junwen; Ma, Haile

2018-04-01

Investigating the kinetics of enzyme activities and browning indexes in food are very essential in understanding the enzyme inactivation and browning pigmentation reaction during drying processing. In order to understand and predict accurately the enzyme inactivation and browning pigmentation of banana slices using Relative Humidity (RH)-convective hot air dryer aided by ultrasound (US) pretreatment, this study was conducted. Drying was carried out with 20 kHz frequency of US-pretreatment using three durations (10 20 and 30 min) and RH (10 20 and 30%) conditions at 70 °C and 2.0 m/s air velocity. The kinetic study of both enzyme inactivation and browning pigmentation results were compared to their relevance of fit in terms of coefficient of correlation (R2), the root mean square error (RMSE) and the reduced chi-square (χ 2). First order and second-order polynomial kinetic model fitted well for enzyme inactivation and browning indexes respectively. Both enzymes inactivation kinetics and enzymatic browning index (EBI) declined significantly (p < 0.05) with increasing drying time in all drying conditions and rate of decrease intensified in longer US-pretreatment duration and lower RH conditions. However, shorter US-pretreatment duration and higher RH conditions reduced the non- enzymatic browning index (NBI) significantly. Again, longer US-pretreatment duration and lower RH shortened the drying time but adversely created more microspores from the micrograph study. Longer US pretreatment and lower RH decrease significantly (p < 0.05) the L* and b* values whereas the a* values was increased.

Dipeptidyl peptidase IV (DPPIV) enzyme activity on immature T-cell line R1.1 is down-regulated by dynorphin-A(1-17) as a non-substrate inhibitor.

PubMed

Gabrilovac, Jelka; Abramić, Marija; Uzarević, Branka; Andreis, Ana; Poljak, Ljiljana

2003-05-30

In this study we examined surface expression of CD26 and the corresponding enzyme activity of dipeptidyl peptidase IV (DPPIV) on the cells of immature murine T-cell line, R1.1. The data obtained have shown that R1.1 cells express high density of surface CD26 as compared to normal thymus cells. This was associated with strong enzyme activity, which, based on substrates and inhibitor specificity, corresponded to DPPIV. The DPPIV enzyme activity of R1.1 cells was 10 times stronger than that found on normal murine thymus cells (V(max) = 39 micromol/min/10(6) cells, vs 3.7 micromol/min/10(6) cells, respectively). Upon activation with anti-CD3, up-regulation of both membrane CD26, as well as of DPPIV enzyme activity on R1.1 cells were observed. The finding of strong DPPIV on R1.1 cells makes them suitable model for testing putative substrates/inhibitors of the enzyme in its natural microenvironment. Since in addition to strong DPPIV, R1.1 cells also express kappa opioid receptors (KOR) [European Journal of Pharmacology 227 (1992) 257], we tested the effect of dynorphin-A(1-17), an endogenous opioid peptide with KOR selectivity, on DPPIV of R1.1 cells. Dynorphin-A(1-17) down-regulated DPPIV in a dose-dependent manner, with the potency similar to that of substance P, a known natural DPPIV substrate [Journal of Pharmacology and Experimental Therapeutics 260 (1992) 1257]. DPPIV down-regulation was resistant to bestatin and thiorphan, the inhibitors of two cell surface peptidases (APN and NEP, respectively) with potential of dynorphin-A(1-17) degradation, suggesting that the mechanism underlying the observed effect does not involve degradative products of dynorphin-A(1-17). DPPIV down-regulation was also resistent to KOR antagonist, NBI, suggesting that the mechanism underlying the observed phenomenon involves neither cointernalization of KOR and DPPIV. Collectively, cells of immature T cell line, R1.1 exert strong DPPIV enzyme activity, which could be down-regulated in the presence of dynorphin-A(1-17) by mechanism that presumably includes non-substrate inhibition. By down-regulating DPPIV, dynorphin-A(1-17) may indirectly affect activity and/or specificity of natural substrates of DPPIV, such as substance P, RANTES, and endomorphins.

The diagnosed mobile limiters of the TJ-II stellarator for plasma boundary studies

NASA Astrophysics Data System (ADS)

de la Cal, E.; Tabarés, F. L.; Tafalla, D.; Cortés, I. García.; Hidalgo, C.; López-Fraguas, A.

TJ-II is a medium size (major radius R=1.5 m, average plasma radius a <0.25 m, on axis magnetic field B=1 T) helical axis stellarator. The main characteristic is its magnetic configuration flexibility, due to the separate control of the different magnetic field coils. The two diagnosed mobile limiters are installed to reduce thermal loads on the thin protection plates of the contacting plasma-chamber regions and to study the plasma edge. First diagnostics are a set of thermocouples, Langmuir probes, H α-detectors and a CCD video camera with different filters (atomic lines of HeI, H α and near IR) looking at the limiter. A method of passive spectroscopy is proposed to map the electron temperature and density over the whole limiter surface by analysing the emission of helium recycling neutrals. It is expected from previous results of other stellarators, that the boundary magnetic topology will have a strong influence on the plasma-wall interaction. The mobile limiters can control the last closed magnetic surface and diagnose the plasma boundary. A qualitative different plasma edge scenario is foreseen between the limiter and the natural island divertor configuration (rational rotational transform inside the limiter radius). Plasma-wall interaction in TJ-II shows very specific features and the optimisation of the plasma edge topology can influence strongly the core plasma parameters. In particular, impurity screening will be a challenge due to the large power density which will be available in future (up to 2 MW NBI for 0.5 s). A safe operation for future high β-plasmas is also required and the mobile limiters should help to remove a fraction of the conductive/convective power.

Enduring, Handling-Evoked Enhancement of Hippocampal Memory Function and Glucocorticoid Receptor Expression Involves Activation of the Corticotropin-Releasing Factor Type 1 Receptor

PubMed Central

Fenoglio, Kristina A.; Brunson, Kristen L.; Avishai-Eliner, Sarit; Stone, Blake A.; Kapadia, Bhumika J.; Baram, Tallie Z.

2011-01-01

Early-life experience, including maternal care, influences hippocampus-dependent learning and memory throughout life. Handling of pups during postnatal d 2–9 (P2–9) stimulates maternal care and leads to improved memory function and stress-coping. The underlying molecular mechanisms may involve early (by P9) and enduring reduction of hypothalamic corticotropin-releasing factor (CRF) expression and subsequent (by P45) increase in hippocampal glucocorticoid receptor (GR) expression. However, whether hypothalamic CRF levels influence changes in hippocampal GR expression (and memory function), via reduced CRF receptor activation and consequent lower plasma glucocorticoid levels, is unclear. In this study we administered selective antagonist for the type 1 CRF receptor, NBI 30775, to nonhandled rats post hoc from P10–17 and examined hippocampus-dependent learning and memory later (on P50–70), using two independent paradigms, compared with naive and vehicle-treated nonhandled, and naive and antagonist-treated handled rats. Hippocampal GR and hypothalamic CRF mRNA levels and stress-induced plasma corticosterone levels were also examined. Transient, partial selective blockade of CRF1 in nonhandled rats improved memory functions on both the Morris watermaze and object recognition tests to levels significantly better than in naive and vehicle-treated controls and were indistinguishable from those in handled (naive, vehicle-treated, and antagonist-treated) rats. GR mRNA expression was increased in hippocampal CA1 and the dentate gyrus of CRF1-antagonist treated nonhandled rats to levels commensurate with those in handled cohorts. Thus, the extent of CRF1 activation, probably involving changes in hypothalamic CRF levels and release, contributes to the changes in hippocampal GR expression and learning and memory functions. PMID:15932935

Creating Hybrid Plasmas With Off-Axis ECCD for Radiating Divertor Studies in DIII-D

NASA Astrophysics Data System (ADS)

Petty, C. C.; Ferron, J. R.; Luce, T. C.; Osborne, T. H.; Petrie, T. W.; Turco, F.; Holcomb, C. T.; Thome, K. E.

2017-10-01

A long duration, high density, high power hybrid scenario has been developed for use in radiative divertor studies in DIII-D. Using 11.2 MW of co-NBI power and 3.4 MW of ECCD, with a total injected energy of up to 56 MJ, high performance hybrid plasmas with βN = 3.7 and H98y2 = 1.5 were created. The hybrid plasmas were fully non-inductive at densities of n 4.2 ×1019 m-3 with central ECCD, but the EC deposition needed to be moved to ρ = 0.45 to avoid the right-hand cutoff when the density was raised to n 5.8 ×1019 m-3 for radiative divertor studies. Although moving the EC deposition to ρ = 0.45 had the effect of dropping τE by 10%, the energy confinement time increased with higher density like τE n0.4, allowing high beta to be maintained. While the plasma current profile displays the usual self-organizing properties of hybrids - an anomalously broad profile with qmin >1 - local current drive can still have a measurable effect on stability, either positively or negatively. For example, hybrid discharges with radial ECH deposited at ρ = 0.45 proved to be more robustly stable to n = 1 modes (can be either a 1/1 or 2/1 mode) than similar discharges with co-ECCD at the same location. Interestingly, the large 1/1 mode had almost no effect on energy confinement but strongly degraded particle confinement; thus this mode needed to be suppressed to achieve the high pedestal densities required for radiative divertor studies. Work supported by USDOE under DE-FC02-04ER54698.

Development of a compact bushing for NBI

NASA Astrophysics Data System (ADS)

de Esch, H. P. L.; Simonin, A.; Grand, C.; Lepetit, B.; Lemoine, D.; Márquez-Mijares, M.; Minea, T.; Caillault, L.; Seznec, B.; Jager, T.; Odic, E.; Kirkpatrick, M. J.; Teste, Ph.; Dessante, Ph.; Almaksour, K.

2017-08-01

Research into a novel type of compact bushing is being conducted through the HVIV (High Voltage holding In Vacuum) partnership between CEA-Cadarache1, GeePs-Centralesupélec4, LPGP3 and LCAR2. The bushing aims to concentrate the high electric field inside its interior, rather than in the vacuum tank. Hence the field emission current is also concentrated inside the bushing and it can be attempted to suppress this so-called dark current by conditioning the internal surfaces and by adding gas. LCAR have performed theoretical quantum mechanical studies of electron field emission and the role of adsorbates in changing the work function. LPGP studied the ionization of gas due to field emission current and the behavior of micro particles exposed to emissive electron current in the vacuum gap under high electric fields. Experiments at Geeps have clarified the role of surface conditioning in reducing the dark current. Geeps also found that adding low pressure nitrogen gas to the vacuum is much more effective than helium in reducing the field emission. An interesting observation is the growth of carbon structures after exposure of an electrode to the electric field. Finally, IRFM have performed experiments on a single stage test bushing that features a 36 cm high porcelain insulator and two cylindrical electrode surfaces in vacuum or low-pressure gas. Using 0.1 Pa N2 gas, the voltage holding exceeded 185 kV over a 40 mm "vacuum" gap without dark current. Above this voltage, exterior breakdowns occurred over the insulator, which was in air. The project will finish with the fabrication of a 2-stage compact bushing, capable to withstand 400 kV.

Negative ion beam development at Cadarache (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simonin, A.; Bucalossi, J.; Desgranges, C.

1996-03-01

Neutral beam injection (NBI) is one of the candidates for plasma heating and current drive in the new generation of large magnetic fusion devices (ITER). In order to produce the required deuterium atom beams with energies of 1 MeV and powers of tens of MW, negative D{sup {minus}} ion beams are required. For this purpose, multiampere D{sup {minus}} beam production and 1 MeV electrostatic acceleration is being studied at Cadarache. The SINGAP experiment, a 1 MeV 0.1 A D{sup {minus}} multisecond beam accelerator facility, has recently started operation. It is equipped with a Pagoda ion source, a multiaperture 60 keVmore » preaccelerator and a 1 MV 120 mA power supply. The particular feature of SINGAP is that the postaccelerator merges the 60 keV beamlets, aiming at accelerating the whole beam to 1 MeV in a single gap. The 1 MV level was obtained in less than 2 weeks, the accumulated voltage on-time of being {approximately}22 min. A second test bed MANTIS, is devoted to the development of multiampere D{sup {minus}} sources. It is capable of driving discharges with current up to 2500 A at arc voltages up to 150 V. A large multicusp source has been tested in pure volume and cesiated operation. With cesium seeding, an accelerated D{sup {minus}} beam current density of up to 5.2 mA/cm{sup 2} (2 A of D{sup {minus}}) was obtained. A modification of the extractor is underway in order to improve this performance. A 3D Monte Carlo code has been developed to simulate the negative ion transport in magnetized plasma sources and optimize magnetic field configuration of the large area D{sup {minus}} sources. {copyright} {ital 1996 American Institute of Physics.}« less

Characterization with microturbulence simulations of the zero particle flux condition in case of a TCV discharge showing toroidal rotation reversal

NASA Astrophysics Data System (ADS)

Mariani, A.; Merlo, G.; Brunner, S.; Merle, A.; Sauter, O.; Görler, T.; Jenko, F.; Told, D.

2016-11-01

In view of the stabilization effect of sheared plasma rotation on microturbulence, it is important to study the intrinsic rotation that develops in tokamaks that present negligible external toroidal torque, like ITER. Remarkable observations have been made on TCV, analysing discharges without NBI injection, as reported in [A. Bortolon et al. 2006 Phys. Rev. Lett. 97] and exhibiting a rotation inversion occurring in conjunction with a relatively small change in the plasma density. We focus in particular on a limited L-mode TCV shot published in [B. P. Duval et al. 2008 Phys. Plasmas 15], that shows a rotation reversal during a density ramp up. In view of performing a momentum transport analysis on this TCV shot, some constraints have to be considered to reduce the uncertainty on the experimental parameters. One useful constraint is the zero particle flux condition, resulting from the absence of direct particle fuelling to the plasma core. In this work, a preliminary study of the reconstruction of the zero particle flux hyper-surface in the physical parameters space is presented, taking into account the effect of the main impurity (carbon) and beginning to explore the effect of collisions, in order to find a subset of this hyper-surface within the experimental error bars. The analysis is done performing gyrokinetic simulations with the local (flux-tube) version of the Eulerian code GENE [Jenko et al 2000 Phys. Plasmas 7 1904], computing the fluxes with a Quasi-Linear model, according to [E. Fable et al. 2010 PPCF 52], and validating the QL results with Non-Linear simulations in a subset of cases.

SciDAC GSEP: Gyrokinetic Simulation of Energetic Particle Turbulence and Transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Zhihong

Energetic particle (EP) confinement is a key physics issue for burning plasma experiment ITER, the crucial next step in the quest for clean and abundant energy, since ignition relies on self-heating by energetic fusion products (α-particles). Due to the strong coupling of EP with burning thermal plasmas, plasma confinement property in the ignition regime is one of the most uncertain factors when extrapolating from existing fusion devices to the ITER tokamak. EP population in current tokamaks are mostly produced by auxiliary heating such as neutral beam injection (NBI) and radio frequency (RF) heating. Remarkable progress in developing comprehensive EP simulationmore » codes and understanding basic EP physics has been made by two concurrent SciDAC EP projects GSEP funded by the Department of Energy (DOE) Office of Fusion Energy Science (OFES), which have successfully established gyrokinetic turbulence simulation as a necessary paradigm shift for studying the EP confinement in burning plasmas. Verification and validation have rapidly advanced through close collaborations between simulation, theory, and experiment. Furthermore, productive collaborations with computational scientists have enabled EP simulation codes to effectively utilize current petascale computers and emerging exascale computers. We review here key physics progress in the GSEP projects regarding verification and validation of gyrokinetic simulations, nonlinear EP physics, EP coupling with thermal plasmas, and reduced EP transport models. Advances in high performance computing through collaborations with computational scientists that enable these large scale electromagnetic simulations are also highlighted. These results have been widely disseminated in numerous peer-reviewed publications including many Phys. Rev. Lett. papers and many invited presentations at prominent fusion conferences such as the biennial International Atomic Energy Agency (IAEA) Fusion Energy Conference and the annual meeting of the American Physics Society, Division of Plasma Physics (APS-DPP).« less

Neonatal vaginal irritation results in long-term visceral and somatic hypersensitivity and increased hypothalamic–pituitary–adrenal axis output in female mice

PubMed Central

Pierce, Angela N.; Zhang, Zhen; Fuentes, Isabella M.; Wang, Ruipeng; Ryals, Janelle M.; Christianson, Julie A.

2015-01-01

Abstract Experiencing early life stress or injury increases a woman's likelihood of developing vulvodynia and concomitant dysregulation of the hypothalamic–pituitary–adrenal (HPA) axis. To investigate the outcome of neonatal vaginal irritation (NVI), female mouse pups were administered intravaginal zymosan on postnatal days 8 and 10 and were assessed as adults for vaginal hypersensitivity by measuring the visceromotor response to vaginal balloon distension (VBD). Western blotting and calcium imaging were performed to measure transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1) in the vagina and innervating primary sensory neurons. Serum corticosterone (CORT), mast cell degranulation, and corticotropin-releasing factor receptor 1 (CRF1) expression were measured as indicators of peripheral HPA axis activation. Colorectal and hind paw sensitivity were measured to determine cross-sensitization resulting from NVI. Adult NVI mice had significantly larger visceromotor response during VBD than naive mice. TRPA1 protein expression was significantly elevated in the vagina, and calcium transients evoked by mustard oil (TRPA1 ligand) or capsaicin (TRPV1 ligand) were significantly decreased in dorsal root ganglion from NVI mice, despite displaying increased depolarization-evoked calcium transients. Serum CORT, vaginal mast cell degranulation, and CRF1 protein expression were all significantly increased in NVI mice, as were colorectal and hind paw mechanical and thermal sensitivity. Neonatal treatment with a CRF1 antagonist, NBI 35965, immediately before zymosan administration largely attenuated many of the effects of NVI. These results suggest that NVI produces chronic hypersensitivity of the vagina, as well as of adjacent visceral and distant somatic structures, driven in part by increased HPA axis activation. PMID:26098441

Assessing and managing water scarcity within the Nile River Transboundary Basin

NASA Astrophysics Data System (ADS)

Butts, M. B.; Wendi, D.; Jessen, O. Z.; Riegels, N. D.

2012-04-01

The Nile Basin is the main source of water in the North Eastern Region of Africa and is perhaps one of the most critical river basins in Africa as the riparian countries constitute 40% of the population on the continent but only 10% of the area. This resource is under considerable stress with rising levels of water scarcity, high population growth, watershed degradation, and loss of environmental services. The potential impacts of climate change may significantly exacerbate this situation as the water resources in the Nile Basin are critically sensitive to climate change (Conway, Hanson, Doherty, & Persechino, 2007). The motivation for this study is an assessment of climate change impacts and adaptation potential for floods and droughts within the UNEP project "Adapting to climate change induced water stress in the Nile River Basin", supported by SIDA. This project is being carried out as collaboration between DHI, the UK Met Office, and the Nile Basin Initiative (NBI). The Nile Basin exhibits highly diverse climatological and hydrological characteristics. Thus climate change impacts and adaptive capacity must be addressed at both regional and sub-basin scales. While the main focus of the project is the regional scale, sub-basin scale modelling is required to reflect variability within the basin. One of the major challenges in addressing this variability is the scarcity of data. This paper presents an initial screening modelling study of the water balance of the Nile Basin along with estimates of expected future impacts of climate change on the water balance. This initial study is focussed on the Ethiopian Highlands and the Lake Victoria regions, where the impact of climate change on rainfall is important. A robust sub-basin based monthly water balance model is developed and applied to selected sub-basins. The models were developed and calibrated using publicly available data. One of the major challenges in addressing this variability within the basin is the scarcity of spatial data and the results for the Kagera sub-basin show that it is important to represent the spatial distribution of the hydro-geographic characteristics such as rainfall, soil type, etc., in order to develop a reasonable representation of the water balance. These initial results show that the changes in the water balance and flow regime under climate change exhibit large uncertainty. From an examination the flow duration curves, however, there seems to be a consensus, based on an ensemble of climate projections, that flows will increase slightly the short term (2011-2030) and decrease significantly in the long term 2080-2099. The large uncertainties together with the natural variability in the Nile suggest that there is a strong need to maximise adaptive capacity with the region.

Fusion Research in Ioffe Institute

NASA Astrophysics Data System (ADS)

Askinazi, L. G.; Afanasyev, V. I.; Altukhov, A. B.; Bakharev, N. N.; Belokurov, A. A.; Bulanin, V. V.; Bykov, A. S.; Chernyshev, F. V.; Chugunov, I.; Dyachenko, V. V.; Esipov, L. A.; Gin, D.; Goncharov, P. R.; Gurchenko, A. D.; Gusakov, E. Z.; Gusev, V. K.; Heuraux, S.; Iblyaminova, A. D.; Irzak, M. A.; Kantor, M. Yu.; Kaveeva, E. G.; Kiviniemi, T.; Khilkevitch, E. M.; Khitrov, S. A.; Khromov, N. A.; Kornev, V. A.; Kouprienko, D. V.; Kurskiev, G. S.; Lashkul, S. I.; Lebedev, S. V.; Leerink, S.; Melnik, A. D.; Minaev, V. B.; Mironov, M. I.; Miroshnikov, I. V.; Mukhin, E. E.; Nesenevich, V. G.; Niskala, P.; Novokhatsky, A. N.; Patrov, M. I.; Perevalov, A. A.; Petrov, M. P.; Petrov, A. V.; Petrov, Yu. V.; Popov, A. Yu.; Rozhansky, V. A.; Rozhdestvenskiy, V. V.; Sakharov, N. V.; Saveliev, A. N.; Senichenkov, I. Yu.; Sergeev, V. Yu.; Shchegolev, P. B.; Shatalin, S. V.; Shcherbinin, O. N.; Shevelev, A. E.; Sidorov, A. V.; da Silva, F.; Smirnov, A. I.; Stepanov, A. Yu.; Sysoeva, E. V.; Teplova, N. V.; Tolstyakov, S. Yu.; Tukachinsky, A. S.; Varfolomeev, V. I.; Vekshina, E. O.; Vildjunas, M. I.; Voronin, A. V.; Voskoboinikov, S. P.; Wagner, F.; Yashin, A. Yu.; Zhubr, N. A.

2015-10-01

In this paper we present the fusion related activities of the Plasma Physics Division at the Ioffe Institute. The first experiments on lower hybrid current drive (LHCD) in a spherical tokamak performed at the Globus-M tokamak (R = 0.36 m, a = 0.24 m, Bt = 0.4 T, Ip = 200 kA) with a novel poloidally oriented grill resulted in an RF driven current of up to 30 kA at (100 kW, 2.5 GHz), exceeding the modelling predictions. At the FT-2 tokamak (R = 0.56 m, a = 0.08 m, Bt = 3 T, Ip = 30 kA) experiments with a traditional toroidally oriented grill revealed no strong dependence of the LHCD density limit on the H/D ratio in spite of LH resonance densities differing by a factor of 3. Microwave Doppler reflectometry (DR) at the Globus-M, and DR and heavy ion beam probe measurements at the tokamak TUMAN-3M (R = 0.53 m, a = 0.24 m, Bt = 1.0 T, Ip = 190 kA) demonstrated geodesic acoustic mode (GAM) suppression at the L to H transition. Observations at FT-2 using Doppler Enhanced Scattering showed that the GAM amplitude is anti-correlated both spatially and temporally to the drift turbulence level and electron thermal diffusivity. For the first time turbulence amplitude modulation at the GAM frequency was found both experimentally and in global gyrokinetic modelling. A model of the L-H transition is proposed based on this effect. The loss mechanisms of energetic ions' (EI) were investigated in the neutral beam injection (NBI) experiments on Globus-M and TUMAN-3M. Empirical scaling of the 2.45 MeV DD neutron rate for the two devices shows a strong dependence on toroidal field Bt1.29 and plasma current Ip1.34 justifying the Bt and Ip increase by a factor of 2.5 for the proposed upgrade of Globus-M. Bursts of ˜1 MHz Alfvenic type oscillations correlating with sawtooth crashes were observed in ohmic TUMAN-3M discharges. The possibility of low threshold parametric excitation of Bernstein and upper hybrid waves trapped in drift-wave eddies resulting in anomalous absorption in electron cyclotron resonance heating (ECRH) experiments in toroidal plasmas was identified theoretically. A novel method of radial correlation Doppler reflectometry is shown to be capable of measuring the turbulence wave-number spectrum in realistic 2D geometry. On the progress in design and fabrication of three diagnostics for ITER developed in the Ioffe institute is reported: neutral particle analysis, divertor Thomson scattering and gamma spectroscopy.

A new Mantle Source Tapped During Episode 55 of the Pu'u O'o Eruption From Kilauea Volcano

NASA Astrophysics Data System (ADS)

Marske, J. P.; Pietruszka, A. J.; Garcia, M. O.; Rhodes, J. M.

2005-12-01

Over 22 years of continuous geochemical monitoring of lavas from the current Pu'u O'o eruption allows us to probe the mantle and crustal processes beneath Kilauea Volcano in unparalleled detail. Episode 55 (1997-present) marks the longest and most voluminous Pu'u O'o eruptive interval. Here we present new Pb, Sr, and Nd isotopic ratios and major- and trace-element abundances for the most recent lavas (1999-2005). MgO variation diagrams show that most of the major-element variations are related to olivine fractionation. However, Pu'u O'o lavas display longer-term systematic decreases in their TiO2, K2O, P2O5 and CaO abundances (at a given MgO) due to changes in the parental magma composition. Incompatible element ratios (K2O/TiO2, Nb/Y, Nb/Zr) and MgO-normalized abundances (Sr, Rb, K) in episode 55 lavas delimit the lowest values observed during the Pu'u O'o eruption. Earlier Pu'u O'o lavas displayed a temporal decrease in highly over moderately incompatible trace-element ratios, near constant SiO2 contents, and a gradual increase in 87Sr/86Sr. However, episode 55 lavas (between days 5500-6500) record an increase in MgO-normalized SiO2 contents and even higher 87Sr/86Sr with near constant incompatible trace-element ratios. Neither a single mantle source composition nor a change in partial melting conditions can explain these observations. Based on 226Ra-230Th-238U disequilibria and partial melting modeling of trace elements, we conclude that Pu'u O'o lavas originate from at least two distinct mantle source components: (1) a recently depleted component that was subsequently remelted to explain the overall decreases of incompatible major- and trace-element ratios and abundances, and (2) a compositionally and isotopically distinct mantle component that was not previously melted within the Hawaiian plume to explain the temporal increase in 87Sr/86Sr and SiO2 abundances and the flattening trend of incompatible trace-element ratios. This second component lies within typical Pb, Sr and Nd isotopic space for Kilauea, but represents a new source composition for the Pu'u O'o eruption. These results can be explained by a recent (1999) change in the size or location of Pu'u O'o's melting region, which allowed this new source to be tapped.

Overview of the TCV tokamak program: scientific progress and facility upgrades

NASA Astrophysics Data System (ADS)

Coda, S.; Ahn, J.; Albanese, R.; Alberti, S.; Alessi, E.; Allan, S.; Anand, H.; Anastassiou, G.; Andrèbe, Y.; Angioni, C.; Ariola, M.; Bernert, M.; Beurskens, M.; Bin, W.; Blanchard, P.; Blanken, T. C.; Boedo, J. A.; Bolzonella, T.; Bouquey, F.; Braunmüller, F. H.; Bufferand, H.; Buratti, P.; Calabró, G.; Camenen, Y.; Carnevale, D.; Carpanese, F.; Causa, F.; Cesario, R.; Chapman, I. T.; Chellai, O.; Choi, D.; Cianfarani, C.; Ciraolo, G.; Citrin, J.; Costea, S.; Crisanti, F.; Cruz, N.; Czarnecka, A.; Decker, J.; De Masi, G.; De Tommasi, G.; Douai, D.; Dunne, M.; Duval, B. P.; Eich, T.; Elmore, S.; Esposito, B.; Faitsch, M.; Fasoli, A.; Fedorczak, N.; Felici, F.; Février, O.; Ficker, O.; Fietz, S.; Fontana, M.; Frassinetti, L.; Furno, I.; Galeani, S.; Gallo, A.; Galperti, C.; Garavaglia, S.; Garrido, I.; Geiger, B.; Giovannozzi, E.; Gobbin, M.; Goodman, T. P.; Gorini, G.; Gospodarczyk, M.; Granucci, G.; Graves, J. P.; Guirlet, R.; Hakola, A.; Ham, C.; Harrison, J.; Hawke, J.; Hennequin, P.; Hnat, B.; Hogeweij, D.; Hogge, J.-Ph.; Honoré, C.; Hopf, C.; Horáček, J.; Huang, Z.; Igochine, V.; Innocente, P.; Ionita Schrittwieser, C.; Isliker, H.; Jacquier, R.; Jardin, A.; Kamleitner, J.; Karpushov, A.; Keeling, D. L.; Kirneva, N.; Kong, M.; Koubiti, M.; Kovacic, J.; Krämer-Flecken, A.; Krawczyk, N.; Kudlacek, O.; Labit, B.; Lazzaro, E.; Le, H. B.; Lipschultz, B.; Llobet, X.; Lomanowski, B.; Loschiavo, V. P.; Lunt, T.; Maget, P.; Maljaars, E.; Malygin, A.; Maraschek, M.; Marini, C.; Martin, P.; Martin, Y.; Mastrostefano, S.; Maurizio, R.; Mavridis, M.; Mazon, D.; McAdams, R.; McDermott, R.; Merle, A.; Meyer, H.; Militello, F.; Miron, I. G.; Molina Cabrera, P. A.; Moret, J.-M.; Moro, A.; Moulton, D.; Naulin, V.; Nespoli, F.; Nielsen, A. H.; Nocente, M.; Nouailletas, R.; Nowak, S.; Odstrčil, T.; Papp, G.; Papřok, R.; Pau, A.; Pautasso, G.; Pericoli Ridolfini, V.; Piovesan, P.; Piron, C.; Pisokas, T.; Porte, L.; Preynas, M.; Ramogida, G.; Rapson, C.; Rasmussen, J. Juul; Reich, M.; Reimerdes, H.; Reux, C.; Ricci, P.; Rittich, D.; Riva, F.; Robinson, T.; Saarelma, S.; Saint-Laurent, F.; Sauter, O.; Scannell, R.; Schlatter, Ch.; Schneider, B.; Schneider, P.; Schrittwieser, R.; Sciortino, F.; Sertoli, M.; Sheikh, U.; Sieglin, B.; Silva, M.; Sinha, J.; Sozzi, C.; Spolaore, M.; Stange, T.; Stoltzfus-Dueck, T.; Tamain, P.; Teplukhina, A.; Testa, D.; Theiler, C.; Thornton, A.; Tophøj, L.; Tran, M. Q.; Tsironis, C.; Tsui, C.; Uccello, A.; Vartanian, S.; Verdoolaege, G.; Verhaegh, K.; Vermare, L.; Vianello, N.; Vijvers, W. A. J.; Vlahos, L.; Vu, N. M. T.; Walkden, N.; Wauters, T.; Weisen, H.; Wischmeier, M.; Zestanakis, P.; Zuin, M.; the EUROfusion MST1 Team

2017-10-01

The TCV tokamak is augmenting its unique historical capabilities (strong shaping, strong electron heating) with ion heating, additional electron heating compatible with high densities, and variable divertor geometry, in a multifaceted upgrade program designed to broaden its operational range without sacrificing its fundamental flexibility. The TCV program is rooted in a three-pronged approach aimed at ITER support, explorations towards DEMO, and fundamental research. A 1 MW, tangential neutral beam injector (NBI) was recently installed and promptly extended the TCV parameter range, with record ion temperatures and toroidal rotation velocities and measurable neutral-beam current drive. ITER-relevant scenario development has received particular attention, with strategies aimed at maximizing performance through optimized discharge trajectories to avoid MHD instabilities, such as peeling-ballooning and neoclassical tearing modes. Experiments on exhaust physics have focused particularly on detachment, a necessary step to a DEMO reactor, in a comprehensive set of conventional and advanced divertor concepts. The specific theoretical prediction of an enhanced radiation region between the two X-points in the low-field-side snowflake-minus configuration was experimentally confirmed. Fundamental investigations of the power decay length in the scrape-off layer (SOL) are progressing rapidly, again in widely varying configurations and in both D and He plasmas; in particular, the double decay length in L-mode limited plasmas was found to be replaced by a single length at high SOL resistivity. Experiments on disruption mitigation by massive gas injection and electron-cyclotron resonance heating (ECRH) have begun in earnest, in parallel with studies of runaway electron generation and control, in both stable and disruptive conditions; a quiescent runaway beam carrying the entire electrical current appears to develop in some cases. Developments in plasma control have benefited from progress in individual controller design and have evolved steadily towards controller integration, mostly within an environment supervised by a tokamak profile control simulator. TCV has demonstrated effective wall conditioning with ECRH in He in support of the preparations for JT-60SA operation.

Influence of the configuration of the magnetic filter field on the discharge structure in the RF driven negative ion source prototype for fusion

NASA Astrophysics Data System (ADS)

Lishev, S.; Schiesko, L.; Wünderlich, D.; Fantz, U.

2017-08-01

The study provides results for the influence of the filter field topology on the plasma parameters in the RF prototype negative ion source for ITER NBI. A previously developed 2D fluid plasma model of the prototype source was extended towards accounting for the particles and energy losses along the magnetic field lines and the presence of a magnetic field in the driver which is the case at the BATMAN and ELISE test-beds. The effect of the magnetic field in the driver is shown for the magnetic field configuration of the prototype source (i.e. a magnetic field produced by an external magnet frame) by comparison of plasma parameters without and with the magnetic field in the driver and for different axial positions of the filter. Since the ELISE-like magnetic field (i.e. a magnetic field produced by a current flowing through the plasma grid) is a new feature planned to be installed at the BATMAN test-bed, its effect on the discharge structure was studied for different strengths of the magnetic field. The obtained results show for both configurations of the magnetic filter the same main features in the patterns of the plasma parameters in the expansion chamber: a strong axial drop of the electron temperature and the formation of a groove accompanied with accumulation of electrons in front of the plasma grid. The presence of a magnetic field in the driver has a local impact on the plasma parameters: the formation of a second groove of the electron temperature in the case of BATMAN (due to the reversed direction of the filter field in the driver) and a strong asymmetry of the electron density. Accounting for the additional losses in the third dimension suppresses the drifts across the magnetic field and, thus, the variations of the electron density in the expansion chamber are less pronounced.

Role of the Mdm2 SNIP 309 Polymorphism in Gastric Mucosal Morphologic Patterns of Patients with Helicobacter pylori Associated Gastritis.

PubMed

Tongtawee, Taweesak; Dechsukhum, Chavaboon; Leeanansaksiri, Wilairat; Kaewpitoon, Soraya; Kaewpitoon, Natthawut; Loyd, Ryan A; Matrakool, Likit; Panpimanmas, Sukij

2016-01-01

The tumor suppressor p53 is as a regulator of cell proliferation, apoptosis and many other biological processes as well as external and internal stress responses. Mdm2 SNIP309 is a negative regulator of 53. Therefore, this study aimed to determine the role of the Mdm2 SNIP 309 polymorphism in the gastric mucosal morphological patterns in patients with Helicobacter pylori associated gastritis. A prospective cross-sectional study was carried out from November 2014 through November 2015. Biopsy specimens were obtained from patients and infection was proven by positive histology. Gastric mucosa specimens were sent to the Molecular Genetics Unit, Institute of Medicine, Suranaree University of Technology where they were tested by molecular methods to detect the patterns of Mdm2 SNIP 309 polymorphism using the real-time PCR hybridization probe method. The results were analyzed and correlated with gastric mucosal morphological patterns by using C-NBI endoscopy. A total of 300 infected patients were enrolled and gastric mucosa specimens were collected. In this study the percentage of Mdm2 SNIP 309 T/T homozygous and Mdm2 SNIP309 G/T heterozygous was 78% and 19 % respectively whereas Mdm2 SNIP309 G/G homozygous was 3%. Mdm2 SNIP 309 T/T homozygous and Mdm2 SNIP309 G/T heterozygosity correlated with type 1 to type 3 gastric mucosal morphological patterns (P<0.01) whereas Mdm2 SNIP309 G/G homozygous correlated with type 4 and type 5 (P<0.01). Our study finds the frequency of Mdm2 SNIP309 G/G in a Thai population is very low, and suggests that this can explain ae Thailand enigma. Types 1 to type 3 are the most common gastric mucosal morphological patterns according to the unique genetic polymorphism of MDM2 SNIP 309 in the Thai population.

Role of toll-like receptor 10 gene polymorphism and gastric mucosal pattern in patients with chronic gastritis.

PubMed

Tongtawee, Taweesak; Bartpho, Theeraya; Wattanawongdon, Wareeporn; Dechsukhum, Chavaboon; Leeanansaksiri, Wilairat; Matrakool, Likit; Panpimanmas, Sukij

2017-07-01

Helicobacter pylori stimulates the host's toll-like receptors (TLRs). Single-nucleotide polymorphism (SNP) of TLRs is related to the manipulation of regulatory cytokines and also implicated in the varied outcomes of the inflammatory response, including the development of precancerous lesions of gastric mucosa and disease progression. We hypothesized that TLR10 rs10004195 polymorphism is associated with gastric mucosal patterns. TLR10 rs10004195 polymorphisms were identified in a total of 400 gastritis patients using the TagMan SNP genotyping assay. Gastric mucosal patterns were classified by Conventional Narrow Band Imaging gastroscopy (C-NBI gastroscopy). Logistic regression was used to analyze the association. The gastritis patients was Type 1, 37.5% of Thai patients. The T/T homozygous genotype was exhibited by the highest percentage (46.5%) of patients, and the A/A homozygous and A/T heterozygous genotypes were exhibited by 20.25% and 33.25%, respectively, of patients. TLR10 rs10004195 was significantly associated with gastric mucosal patterns. After adjusting for confounding factors, patients with the A/A homozygous genotype showed a significantly increased risk of severe inflammation (OR=1.35, 95% CI=0.97-2.13, p=0.028). Patients with the A/T heterozygous and T/T homozygous genotypes showed a significantly increased risk of mild inflammation (OR=1.24, 95% CI=0.78-2.07, p=0.042 and OR=1.78, 95% CI=0.51-3.35, p=0.001, respectively). Our results indicate that the presence of TLR10 rs10004195, A/T heterozygous, and T/T homozygous genotypes is associated with type 1, 2, and 3 whereas that of the A/A homozygous genotype is associated with type 4 and 5 of gastric mucosal patterns. This suggests that the A/A homozygous genotype contributes to severe inflammation in H. pylori-associated gastritis in Thai patients.

Long-pulse stability limits of the ITER baseline scenario

DOE PAGES

Jackson, G. L.; Luce, T. C.; Solomon, W. M.; ...

2015-01-14

DIII-D has made significant progress in developing the techniques required to operate ITER, and in understanding their impact on performance when integrated into operational scenarios at ITER relevant parameters. We demonstrated long duration plasmas, stable to m/n =2/1 tearing modes (TMs), with an ITER similar shape and I p/aB T, in DIII-D, that evolve to stationary conditions. The operating region most likely to reach stable conditions has normalized pressure, B N≈1.9–2.1 (compared to the ITER baseline design of 1.6 – 1.8), and a Greenwald normalized density fraction, f GW 0.42 – 0.70 (the ITER design is f GW ≈ 0.8).more » The evolution of the current profile, using internal inductance (l i) as an indicator, is found to produce a smaller fraction of stable pulses when l i is increased above ≈ 1.1 at the beginning of β N flattop. Stable discharges with co-neutral beam injection (NBI) are generally accompanied with a benign n=2 MHD mode. However if this mode exceeds ≈ 10 G, the onset of a m/n=2/1 tearing mode occurs with a loss of confinement. In addition, stable operation with low applied external torque, at or below the extrapolated value expected for ITER has also been demonstrated. With electron cyclotron (EC) injection, the operating region of stable discharges has been further extended at ITER equivalent levels of torque and to ELM free discharges at higher torque but with the addition of an n=3 magnetic perturbation from the DIII-D internal coil set. Lastly, the characterization of the ITER baseline scenario evolution for long pulse duration, extension to more ITER relevant values of torque and electron heating, and suppression of ELMs have significantly advanced the physics basis of this scenario, although significant effort remains in the simultaneous integration of all these requirements.« less

Improving evapotranspiration processes in distrubing hydrological models using Remote Sensing derived ET products.

NASA Astrophysics Data System (ADS)

Abitew, T. A.; van Griensven, A.; Bauwens, W.

2015-12-01

Evapotranspiration is the main process in hydrology (on average around 60%), though has not received as much attention in the evaluation and calibration of hydrological models. In this study, Remote Sensing (RS) derived Evapotranspiration (ET) is used to improve the spatially distributed processes of ET of SWAT model application in the upper Mara basin (Kenya) and the Blue Nile basin (Ethiopia). The RS derived ET data is obtained from recently compiled global datasets (continuously monthly data at 1 km resolution from MOD16NBI,SSEBop,ALEXI,CMRSET models) and from regionally applied Energy Balance Models (for several cloud free days). The RS-RT data is used in different forms: Method 1) to evaluate spatially distributed evapotransiration model resultsMethod 2) to calibrate the evotranspiration processes in hydrological modelMethod 3) to bias-correct the evapotranpiration in hydrological model during simulation after changing the SWAT codesAn inter-comparison of the RS-ET products shows that at present there is a significant bias, but at the same time an agreement on the spatial variability of ET. The ensemble mean of different ET products seems the most realistic estimation and was further used in this study.The results show that:Method 1) the spatially mapped evapotranspiration of hydrological models shows clear differences when compared to RS derived evapotranspiration (low correlations). Especially evapotranspiration in forested areas is strongly underestimated compared to other land covers.Method 2) Calibration allows to improve the correlations between the RS and hydrological model results to some extent.Method 3) Bias-corrections are efficient in producing (sesonal or annual) evapotranspiration maps from hydrological models which are very similar to the patterns obtained from RS data.Though the bias-correction is very efficient, it is advised to improve the model results by better representing the ET processes by improved plant/crop computations, improved agricultural management practices or by providing improved meteorological data.

Origin of Permian OIB-like basalts in NW Thailand and implication on the Paleotethyan Ocean

NASA Astrophysics Data System (ADS)

Wang, Yuejun; He, Huiying; Zhang, Yuzhi; Srithai, Boontarika; Feng, Qinglai; Cawood, Peter A.; Fan, Weiming

2017-03-01

The basaltic rocks in NW Thailand belong to part of giant Southeast Asian igneous zone that delineates the extension of the Paleotethyan Ocean from SW China into NW Thailand. The Chiang Mai basaltic samples from the Chiang Dao, Fang, Lamphun and Ban Sahakorn sections are divisible into two groups of high-iron basalt. Group 1 has SiO2 of 38.30-49.18 wt.%, FeOt of 13.09-25.37 wt.%, MgO of 8.38-1.60 wt.%, TiO2 of 3.92-6.30 wt.%, which is rarely observed in nature. Group 2 shows SiO2 = 44.71-49.21 wt.%, FeOt = 10.88-14.34 wt.%, MgO = 5.24-16.11 wt.%, TiO2 = 2.22-3.07 wt.% and mg# = 44-70. Olivine and pyroxene are responsible for the fractionation of the Group 2 magma whereas low oxygen fugacity during the late-stage differentiation of the Group 1 magma prolonged fractionation of ilmenite and magnetite. The onset of ilmenite and magnetite fractionations controls the distinct differentiation commencing at MgO = 7 wt.%. Both groups show similar REE and primitive mantle-normalized patterns with insignificant Eu, Nb-Ta and Zr-Hf anomalies. They have similar Nd isotopic compositions with εNd (t) values ranging from + 2.8 to + 3.7 and similar Nb/La, Nb/U, Th/La, Zr/Nb, Th/Ta, La/Yb, Nb/Th, Nb/Y and Zr/Y, resembling those of OIB-like rocks. The representative basaltic sample yields the argon plateau age of 282.3 ± 1.4 Ma, suggestive of Early Permian origin. Our data argue for Group 1 and Group 2 are coeval in the intra-oceanic seamount setting within the Paleotethyan Ocean, which at least continued till 283 Ma. These data, along with other observations, suggest that the Inthanon zone defines the main Paleotethyan suture zone, which northerly links with the Changning-Menglian suture zone in SW China.

Linking tephrochronology and soil characteristics in the Sila and Nebrodi Mountains, Italy

NASA Astrophysics Data System (ADS)

Raab, Gerald; Halpern, Dieter; Scarciglia, Fabio; Raimondi, Salvatore; de Castro Portes, Raquel; Norton, Kevin; Egli, Markus

2017-04-01

Mediterranean soils are an important key to understanding past volcanic events and landscape evolution. The influence and timing of Quaternary volcanic events on soils, however, remains still poorly understood in southern Italy. We used a multi-method approach to explore the origin and age of volcanic deposits (soils) in Sicily and Calabria. By comparing the geochemical signature of the soils with the chemical fingerprint of magmatic effusive rocks in southern Italy, we tried to identify the source material. It seems that the investigated soils on the Nebrodi (Sicily) and Sila (Calabria) mountains were both influenced by volcanic deposits having a high-K calc-alkaline series volcanic background. The Aeolian islands (Lipari and Vulcano) are the most likely sources of origin. Due to weathering processes of the volcanic sediments and the partial mixing with the underlying non-volcanic parent material, a direct relation with the potential source areas was not always straightforward. Immobile elements and their corresponding ratios (e.g. the Nb/Y vs Zr/Ti plot) or trace elements (Co, Th) and rare earth elements gave better hints of the origin of the deposits. Radiocarbon dating of the stable soil organic fraction (H2O2 resistant) indicated a minimum age of 8 - 10 ka of the Nebrodi and Sila soils. The chemical proxy of alteration (CPA) and weathering index according to Parker (WIP) were tested as proxies for an age estimate of the volcanic deposits and duration of soil formation. The soils and, subsequently, landscape are characterized by multiple volcanic depositional phases for the last 30 - 50 ka in the Sila mountains and about 70 ka in the Nebrodi mountains. We show that a multi-method approach (numerical dating, relative dating using weathering indices and the forensic procedure) enabled the identification of potential source areas, gave tentative age estimates of the ash deposits, duration of soil formation and, therefore, improved our understanding of volcanic landscape evolution.

KINECT 3: A Phase 3 Randomized, Double-Blind, Placebo-Controlled Trial of Valbenazine for Tardive Dyskinesia.

PubMed

Hauser, Robert A; Factor, Stewart A; Marder, Stephen R; Knesevich, Mary Ann; Ramirez, Paul M; Jimenez, Roland; Burke, Joshua; Liang, Grace S; O'Brien, Christopher F

2017-05-01

Tardive dyskinesia is a persistent movement disorder induced by dopamine receptor blockers, including antipsychotics. Valbenazine (NBI-98854) is a novel, highly selective vesicular monoamine transporter 2 inhibitor that demonstrated favorable efficacy and tolerability in the treatment of tardive dyskinesia in phase 2 studies. This phase 3 study further evaluated the efficacy, safety, and tolerability of valbenazine as a treatment for tardive dyskinesia. This 6-week, randomized, double-blind, placebo-controlled trial included patients with schizophrenia, schizoaffective disorder, or a mood disorder who had moderate or severe tardive dyskinesia. Participants were randomly assigned in a 1:1:1 ratio to once-daily placebo, valbenazine at 40 mg/day, or valbenazine at 80 mg/day. The primary efficacy endpoint was change from baseline to week 6 in the 80 mg/day group compared with the placebo group on the Abnormal Involuntary Movement Scale (AIMS) dyskinesia score (items 1-7), as assessed by blinded central AIMS video raters. Safety assessments included adverse event monitoring, laboratory tests, ECG, and psychiatric measures. The intent-to-treat population included 225 participants, of whom 205 completed the study. Approximately 65% of participants had schizophrenia or schizoaffective disorder, and 85.5% were receiving concomitant antipsychotics. Least squares mean change from baseline to week 6 in AIMS dyskinesia score was -3.2 for the 80 mg/day group, compared with -0.1 for the placebo group, a significant difference. AIMS dyskinesia score was also reduced in the 40 mg/day group (-1.9 compared with -0.1). The incidence of adverse events was consistent with previous studies. Once-daily valbenazine significantly improved tardive dyskinesia in participants with underlying schizophrenia, schizoaffective disorder, or mood disorder. Valbenazine was generally well tolerated, and psychiatric status remained stable. Longer trials are necessary to understand the long-term effects of valbenazine in patients with tardive dyskinesia.