[Long term results of exclusive chemotherapy for glottic squamous cell carcinoma complete clinical responders after induction chemotherapy].

PubMed

Vachin, F; Hans, S; Atlan, D; Brasnu, D; Menard, M; Laccourreye, O

2004-06-01

To evaluate the long-term results of exclusive chemotherapy for T1-T3N0M0 glottic squamous cell carcinoma complete clinical responders after induction chemotherapy. Between 1985 and 2000, 69 patients with glottic squamous cell carcinoma complete clinical responders after induction chemotherapy were managed with exclusive chemotherapy at our department. Chemotherapy associated platinum and fluorouracil. This retrospective analysis evaluated actuarial survival, treatment morbidity, oncologic events and laryngeal preservation. Various independent factors were tested for potential correlation with survival and local recurrence. The 5-year Kaplan-Meier actuarial survival, local control, lymph node control estimate were 83,6%, 64,8%, 98,6% respectively. Chemotherapy never resulted in death. The 10-year actuarial metachronous second primary tumors estimate was 32%. The overall laryngeal preservation rate was 98,6%. Altogether our data and the review of the literature suggest that in patients achieving a complete clinical response after and induction based chemotherapy regimen, the completion of an exclusive chemotherapy regimen appears to be a valid alternative to the conventional use of radiotherapy or chemo-radiation protocols.

Radiotherapy for T1-2N0 glottic cancer: a multivariate analysis of predictive factors for the long-term outcome in 1050 patients and a prospective assessment of quality of life and voice handicap index in a subset of 233 patients.

PubMed

Al-Mamgani, A; van Rooij, P H; Woutersen, D P; Mehilal, R; Tans, L; Monserez, D; Baatenburg de Jong, R J

2013-08-01

To evaluate the outcomes of patients with early stage glottic cancer (GC) treated with radiotherapy (RT). The current study report on a retrospective analysis of oncologic outcome of 1050 patients with T1-2N0 glottic cancer treated with radiotherapy. Prospective assessment of quality of life (QoL) and voice handicap index (VHI) was performed in all patients treated from 2006 onwards (n = 233). Local control (LC), regional control (RC), disease-free survival (DFS), overall survival (OS), quality of life and voice handicap index. After a median follow-up of 90 months (range 3-309), the actuarial rates of local control, regional control, disease-free survival and overall survival were 85%, 99%, 84% and 81% at 5 years and 82%, 98%, 80% and 61% at 10 years, respectively. On multivariate analysis, T2 tumours, smoking after radiotherapy and conventional radiation scheme correlated significantly with poor local control. Patients who continued smoking after radiotherapy had also significantly lower overall survival rates (OR 4.3, P < 0.001). Hypothyroidism was reported in 18% of patients. Slight and temporary deterioration of quality of life scores was reported. Patient-reported xerostomia and dysphagia at 48 months were -7.1 and -6.5, compared with baseline, respectively. Voice handicap index improved significantly from 37 at baseline to 18 at 48 months. Patients with T2b and those who continued smoking had significantly worse voice handicap index. In the current study, excellent outcome with good quality of life and voice handicap index scores were reported. T2 tumours, in particular T2b, and continuing smoking after radiotherapy correlated significantly with poor local control and worse voice handicap index. © 2013 John Wiley & Sons Ltd.

Structural, morphological and magnetic properties of Sr0.3La0.48Ca0.25n[Fe(2-0.4/n)O3]Co0.4 (n = 5.5, 5.6,5.7,5.8, 5.9, 6.0) hexaferrites prepared by facile ceramic route methodology

NASA Astrophysics Data System (ADS)

Rehman, Khalid Mehmood Ur; Liu, Xiansong; Yang, Yujie; Feng, Shuangjiu; Tang, Jin; Ali, Zulfiqar; Wazir, Z.; Khan, Muhammad Wasim; Shezad, Mudssir; Iqbal, Muhammad Shahid; Zhang, Cong; Liu, Chaocheng

2018-03-01

In present work, M-type strontium hexaferrite with chemical composition of Sr0.3La0.48Ca0.25n[Fe(2-0.4/n)O3]Co0.4 (n = 5.5, 5.6, 5.7, 5.8, 5.9, 6.0) magnetic powder were synthesized by using facile ceramic route methodology. The structural, morphological and magnetic properties of the products were investigated by using X-rays diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) techniques, respectively. There is a single magnetoplumbite phase in the magnetic powders containing (5.5 ≤ n ≤5.8) and (n ≥ 5.9) magnetic some impurities begin to seem in the structure. The magnets have shaped hexagonal structures. Magnetic properties of the samples were metric by permanent magnetic measuring equipment Vibrating Sample Magnetometer, respectively. We report our investigation of n-aggregation iron content on crystalline size characterization and magnetic properties of the specimen. It is originate that the desirable quantity of n-aggregation iron content substitution may curiously increase saturation magnetization (Ms) and intrinsic coercivity (Hc). With the iron addition for the same sintering temperature at 1260 °C, (Ms) and (Hc) first increase and then decrease gradually.

Results of irradiation of (U0.55Pu0.45)N and (U0.4Pu0.6)N fuels in BOR-60 up to ˜12 at.% burn-up

NASA Astrophysics Data System (ADS)

Rogozkin, B. D.; Stepennova, N. M.; Fedorov, Yu. Ye.; Shishkov, M. G.; Kryukov, F. N.; Kuzmin, S. V.; Nikitin, O. N.; Belyaeva, A. V.; Zabudko, L. M.

2013-09-01

In the article presented are the results of post-irradiation tests of helium bonded fuel pins with mixed mononitride fuel (U0.55Pu0.45)N and (U0.4Pu0.6)N having 85% density irradiated in BOR-60 reactor. Achieved maximum burn-up was, respectively, equal to 9.4 and 12.1 at.% with max linear heat rates 41.9 and 54.5 kW/m. Maximum irradiation dose was 43 dpa. No damage of claddings made of ChS-68 steel (20% cold worked) was observed, and ductility margin existed. Maximum depth of cladding corrosion was within 15 μm. Swelling rates of (U0.4Pu0.6)N and (U0.55Pu0.45)N were, respectively, ˜1.1% and ˜0.68% per 1 at.%. Gas release rate did not exceed 19.3% and 19%. Pattern of porosity distribution in the fuel influenced fuel swelling and gas release rates. Plutonium and uranium are uniformly distributed in the fuel, local minimum values of their content being caused by pores and cracks in the pellets. The observable peaks in content distribution are probably connected with the local formation of isolated phases (e.g. Mo, Pd) while the minimum values refer to fuel pores and cracks. Xenon and cesium tend to migrate from the hot sections of fuel, and therefore their min content is observed in the central section of the fuel pellets. Phase composition of the fuel was determined with X-ray diffractometer. The X-ray patterns of metallographic specimens were obtained by the scanning method (the step was 0.02°, the step exposition was equal to 2 s). From the X-ray diffraction analysis data, it follows that the nitrides of both fuel types have the single-phase structure with an FCC lattice (see Table 6).

An AlN/Al 0.85Ga 0.15N high electron mobility transistor

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

Baca, Albert G.; Armstrong, Andrew M.; Allerman, Andrew A.

2016-07-22

An AlN barrier high electron mobility transistor (HEMT) based on the AlN/Al 0.85Ga 0.15N heterostructure was grown, fabricated, and electrically characterized, thereby extending the range of Al composition and bandgap for AlGaN channel HEMTs. An etch and regrowth procedure was implemented for source and drain contact formation. A breakdown voltage of 810 V was achieved without a gate insulator or field plate. Excellent gate leakage characteristics enabled a high I on/I off current ratio greater than 10 7 and an excellent subthreshold slope of 75 mV/decade. A large Schottky barrier height of 1.74 eV contributed to these results. In conclusion,more » the room temperature voltage-dependent 3-terminal off-state drain current was adequately modeled with Frenkel-Poole emission.« less

Preparation of UC0.07-0.10N0.90-0.93 spheres for TRISO coated fuel particles

NASA Astrophysics Data System (ADS)

Hunt, R. D.; Silva, C. M.; Lindemer, T. B.; Johnson, J. A.; Collins, J. L.

2014-05-01

The US Department of Energy is considering a new nuclear fuel that would be less susceptible to ruptures during a loss-of-coolant accident. The fuel would consist of tristructural isotropic coated particles with dense uranium nitride (UN) kernels with diameters of 650 or 800 μm. The objectives of this effort are to make uranium oxide microspheres with adequately dispersed carbon nanoparticles and to convert these microspheres into UN spheres, which could be then sintered into kernels. Recent improvements to the internal gelation process were successfully applied to the production of uranium gel spheres with different concentrations of carbon black. After the spheres were washed and dried, a simple two-step heat profile was used to produce porous microspheres with a chemical composition of UC0.07-0.10N0.90-0.93. The first step involved heating the microspheres to 2023 K in a vacuum, and in the second step, the microspheres were held at 1873 K for 6 h in flowing nitrogen.

Glottic Closing Force Versus Laryngeal Adductory Pressure in the Canine Larynx.

PubMed

Paniello, Randal C; Bhatt, Neel K

2017-03-01

The strength of glottic closure with recurrent laryngeal nerve (RLN) stimulation has been indirectly measured experimentally by determining the squeezing pressure on a balloon inserted between the vocal folds, termed laryngeal adductory pressure (LAP). In this study, we sought to measure glottic closing force (GCF) directly and compare these results to LAP measures obtained with identical stimulation parameters. In canines, a method for measuring GCF was developed in which a suture was looped through a lateral thyrotomy hole, around the vocal process and back, then attached to a force gauge. The RLN was maximally stimulated and GCF recorded. The LAP was then measured as previously described, using the same stimuli. This process was repeated at 9 stimulation frequencies in 10-Hz intervals from 20 to 100 Hz. The GCF and LAP were compared using Pearson's correlation coefficient (PCC). Both sides were measured in 16 dogs, resulting in 32 data sets. The LAP measures were obtained at all frequencies, while GCF was obtained in 246 of 288 (85.4%) attempts. The maximum GCF for each dog typically occurred at 80 to 100 Hz and averaged 0.287 ± 0.106 newtons. Plotting GCF versus LAP for each hemilaryngeal preparation, the mean PCC was 0.932 ± .042 (range, 0.802-0.987). The mean PCC did not differ between control (n = 26) and postoperative (n = 6) hemilarynges. This method for measuring GCF appears valid. The high Pearson's correlation coefficient indicates strong covariance between GCF and LAP, demonstrating that they are both measures of the same physical property. The LAP is easier to perform and more consistently obtained.

[The application of full thicknes skin graft inpartial laryngectomy for glottic carcinoma].

PubMed

Fu, Y G; Sun, D Z; Yang, P Z; Chen, Y L; Chen, Z P; Yang, Z K

2016-08-05

Objective: The aim of this study is to explore the experience and advantages of the application of full thicknes skin graft in glottic carcinoma.partial laryngectomy for glottic carcinoma. Method: One hundred and forty-three patients with glottic cancer were treated with partial laryngectomy.Among those,78 cases were repaired with full-thickness skin graft and 65 cases were repaired with sternohyoid muscular fasciae.Compared the time of extubation and the formation of granulation in laryngeal cavity after operation between the two groups. Result: In the group of full-thickness skin graft,the mean time of decannulation was 6.8 days,5 cases with growth of granulation after operation.In other group,the mean time of decannulation was 10.7 days,16 cases with growth of granulation after operation.The mean time of decannulation( t =-4.739, P <0.01) and the growth of granulation(χ²=9.379, P <0.01) are significantly different between the two groups.No laryngostenosis was found in all patients. Conclusion: The application of full-thicknes skin graft in partial laryngectomy for glottic carcinoma.can shortthe time of extubation and reduce the formation of granulation. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Optical and transport properties of LaTi{sub 1−x}M{sub x}(O,N){sub 3±δ} (x=0; 0.1, M=Nb{sup 5+}, W{sup 6+}) thin films prepared by plasma ammonolysis

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

Maegli, Alexandra E.; Sagarna, Leyre; Populoh, Sascha

2014-03-15

Oxynitride thin films of composition LaTi{sub 1−x}M{sub x}(O,N){sub 3±δ} with x=0; 0.1 and M=Nb{sup 5+}, W{sup 6+} were prepared by nitridation via microwave-induced plasma (MIP) ammonolysis, which allowed keeping the nitridation time short (16 min). The higher possible oxidation states of the B-site substituents (Nb{sup 5+}, W{sup 6+}) with respect to Ti{sup 4+} caused higher N content for LaTi{sub 0.9}Nb{sub 0.1}(O,N){sub 3±δ} and LaTi{sub 0.9}W{sub 0.1}(O,N){sub 3±δ} compared to LaTiO{sub 2}N due to charge-compensation. XPS O 1s and N 1s core level and valence band spectra evidenced for increasing N content in the order LaTiO{sub 2}N

Piezoelectric characterization of Sc0.26Al0.74N layers on Si (001) substrates

NASA Astrophysics Data System (ADS)

Sinusía Lozano, M.; Pérez-Campos, A.; Reusch, M.; Kirste, L.; Fuchs, Th; Žukauskaitė, A.; Chen, Z.; Iriarte, G. F.

2018-03-01

Scandium aluminum nitride (ScAlN) films have been synthesized by pulsed-DC reactive magnetron sputtering. The degree of c-axis orientation as well as piezoelectric characteristics of the Sc0.26Al0.74N thin films grown on Si (001) at various discharge powers and processing pressures values have been investigated. According to x-ray diffraction (XRD) measurements, the texture of the as-grown Sc0.26Al0.74N thin films becomes more prominent in the [0001]-direction at the highest target power (700 W) and at the lowest processing pressure (4 mTorr). The piezoelectric response, as determined by measuring the d33 piezoelectric constant, shows a maximum value of -12 pC/N also at 4 mTorr and 700 W, confirming a direct correlation between the d33 piezoelectric constant and the degree of orientation in the [0001]-direction. The atomic concentration of Sc and Al in the synthesized ScAlN thin film, determined by secondary ion mass spectroscopy (SIMS), reveals a Sc concentration lower than in the ScAl alloy target. The piezoresponse force microscopy (PFM) shows homogeneous polarity distribution with no inversion domains. The piezoelectric layers have been used to fabricate and measure surface acoustic wave (SAW) resonators on a Sc0.26Al0.74N/Si (001) bilayer system with resonance frequency of 1.4 GHz and coupling coefficient of 0.567. Such characteristic in the frequency response reveals the potential of these materials for advanced SAW devices in applications such as next generation (5 G) wireless communication systems.

(Cu 0.5Tl 0.5)Ba 2Ca n-1 Cu n- yGe yO 2 n+4- δ ( n = 3, 4 and y = 0.5, 0.75, 1.0); superconductors with GeO 2 planes

NASA Astrophysics Data System (ADS)

Khan, Nawazish A.; Irfan, M.

2008-12-01

We have successfully synthesized germanium doped (Cu 0.5Tl 0.5)Ba 2Ca n-1 Cu n- yGe yO 2 n+4- δ ( n = 3, 4 and y = 0, 0.5, 0.75, 1.0) superconductors and investigated the effect of Ge doping on the superconducting properties of these compounds. The solubility of Ge till y = 1 in the CuO 2 planes of (Cu 0.5Tl 0.5)Ba 2Ca 2Cu 3- yGe yO 10- δ, have been found to give superconductivity above 77 K. To our surprise an enhanced superconductivity is observed with the doping of semiconductor germanium in some samples. The enhanced superconductivity associated with mixed CuO 2/GeO 2 planes can be extremely useful for the understanding of mechanism of superconductivity; since we very well know the properties of germanium based semiconductors.

Changes of electronic properties of p-GaN(0 0 0 1) surface after low-energy N+-ion bombardment

NASA Astrophysics Data System (ADS)

Grodzicki, M.; Mazur, P.; Ciszewski, A.

2018-05-01

The p-GaN(0 0 0 1) crystal with a relatively low acceptor concentration of 5 × 1016 cm-3 is used in these studies, which are carried out in situ under ultrahigh vacuum (UHV) by ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED). The p-GaN(0 0 0 1)-(1 × 1) surface is achieved by thermal cleaning. N+-ion bombardment by a 200 eV ion beam changes the surface stoichiometry, enriches it with nitrogen, and disorders it. Such modified surface layer inverts its semiconducting character from p- into n-type. The electron affinity for the already cleaned p-GaN surface and that just after bombardment shows a shift from 2.2 eV to 3.2 eV, as well as an increase of band bending at the vacuum/surface interface from 1.4 eV to 2.5 eV. Proper post-bombardment heating of the sample restores the initial atomic order of the modified layer, leaving its n-type semiconducting character unchanged. The results of the measurements are discussed based on two types of surface states concepts.

Risk of Fatal Cerebrovascular Accidents after External Beam Radiation Therapy for Early Stage Glottic Larynx Cancer

PubMed Central

Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O’Malley, Bert; Weinstein, Gregory S.; Bekelman, Justin E.

2013-01-01

Background This study compared the risk of fatal cerebrovascular accidents (CVA) in patients with early stage glottic larynx cancer receiving surgery or external beam radiation therapy (EBRT). Methods and Materials Using a competing risks survival analysis, we compared the risk of death due to CVA among patients with early stage glottic larynx cancer receiving surgery or EBRT in the SEER database. Results The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8 %; 95% CI 2.3%–3.4%) compared to surgery (1.5 %; 95% CI 0.8 %–2.3%, p= 0.024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted HR 1.75; 95% CI 1.04–2.96, p= 0.037). Conclusion Treatment of early stage glottic larynx cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. PMID:23595858

An AlN/Al{sub 0.85}Ga{sub 0.15}N high electron mobility transistor

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

Baca, Albert G.; Armstrong, Andrew M.; Allerman, Andrew A.

2016-07-18

An AlN barrier high electron mobility transistor (HEMT) based on the AlN/Al{sub 0.85}Ga{sub 0.15}N heterostructure was grown, fabricated, and electrically characterized, thereby extending the range of Al composition and bandgap for AlGaN channel HEMTs. An etch and regrowth procedure was implemented for source and drain contact formation. A breakdown voltage of 810 V was achieved without a gate insulator or field plate. Excellent gate leakage characteristics enabled a high I{sub on}/I{sub off} current ratio greater than 10{sup 7} and an excellent subthreshold slope of 75 mV/decade. A large Schottky barrier height of 1.74 eV contributed to these results. The room temperature voltage-dependent 3-terminalmore » off-state drain current was adequately modeled with Frenkel-Poole emission.« less

Glottic and supraglottic pT3 squamous cell carcinoma: outcomes with transoral laser microsurgery.

PubMed

Pantazis, Dimitrios; Liapi, Georgia; Kostarelos, Dimitrios; Kyriazis, Georgios; Pantazis, Theodoros-Leonidas; Riga, Maria

2015-08-01

Patients diagnosed with T3 squamous cell laryngeal carcinomas are nowadays offered either organ-preserving surgical or non-surgical treatment, with the optimum approach remaining undefined. No direct comparison of organ-preserving therapeutical options, stratified by anatomical subsites is available in the literature. The aim of this study is to present institutional treatment outcomes for laser-assisted microsurgery (TLM) of laryngeal T3 squamous cell carcinomas and review the relevant literature. Sixty-four consecutive, previously untreated patients were evaluated. Twenty-four supraglottic and 19 glottic patients were treated with TLM and neck dissection, tumor exposure and postoperative upstaging of the tumors through pathology evaluation of the specimens being the only exclusion criteria. Five-year disease-specific survival and organ preservation rates for supraglottic carcinomas were both 91.7 %. The respective values for glottic carcinomas were 63.2 and 73.3 %. TLM-treated T3 supraglottic tumors seem to attribute better outcomes than T3 glottic tumors in terms of recurrence-free survival, organ preservation and local control (p = 0.01, <0.0001 and 0.01, respectively). The results of this study suggest that TLM-treated T3 supraglottic tumors have a good prognosis, substantially better than that of glottic tumors. A literature review, on the other hand, attributes to chemo-radiation-treated T3 supraglottic tumors a considerably poorer prognosis. Further studies of homogenous populations in terms of anatomical subsites are needed in order to reach a consensus regarding treatment of T3 laryngeal tumors.

Polarized Infrared Reflectance Studies of Quaternary In0.04Al0.06Ga0.90N

NASA Astrophysics Data System (ADS)

Bakhori, S. K. Mohd; Lee, S. C.; Ahmad, M. A.; Ng, S. S.; Hassan, H. Abu

2010-07-01

Group III-nitride has re-gained considerable interest recently as wide direct band gap semiconductor materials for opto-electronic and high power devices. The quaternary InAlGaN have great flexibility in tailoring their band gap profile while maintaining their lattice-matching and structural integrity. In this study, we report for the first time the polarized infrared (IR) reflectance studies of quaternary In0.04Al0.06Ga0.90N by using Fourier transform infrared spectroscopy of Perkin-Elmer. The quaternary In0.04Al0.06Ga0.90N epilayers was grown on sapphire by molecular beam epitaxy. The polarized IR reflectance spectra obtained at incident angle of 15° were then compared with modeling spectrum of damped harmonic oscillator. Through this study, the transverse and longitudinal optical phonon modes of quaternary In0.04Al0.06Ga0.90N epilayers were obtained.

Comparison of the outcomes of stereotactic body radiotherapy and surgery in elderly patients with cT1-2N0M0 non-small cell lung cancer.

PubMed

Nakagawa, Tatsuo; Negoro, Yoshiharu; Matsuoka, Tomoaki; Okumura, Norihito; Dodo, Yoshihiro

2014-07-01

This study aimed to compare the outcomes of stereotactic body radiotherapy (SBRT) and surgery in elderly patients with cT1-2N0M0 non-small cell lung cancer (NSCLC). Elderly patients (≥75 years) with cT1-2 (≤5 cm) N0M0 NSCLC who were treated with SBRT (n=35) or surgery (n=183) between January 2001 and December 2011 were analyzed. The following radiation doses were administered: 48 Gy/4-6 fractions in 12 patients; 50 Gy/4-5 fractions in 20; and 60 Gy/8 fractions in 3. The following surgical methods were performed: pneumonectomy in 2 patients, lobectomy in 154, segmentectomy in 23, and wedge resection in 4. Patients in the SBRT group had a higher mean age, a worse performance status, and a lower percentage of forced expiratory volume in 1.0 s than those in the surgery group. The overall 5-year survival rates were 43.8% and 67.6% for the SBRT and surgery groups, respectively (p=0.057, log-rank test). Regarding tumor diameter, patients in the surgery group survived significantly longer than did those in the SBRT group (>20-mm tumors, p=0.027; >30-mm tumors p=0.043), whereas survival did not differ significantly between the groups for ≤20-mm tumors (p=0.982). Multivariate analysis confirmed the improved survival in the surgery group compared to the SBRT group for all tumors (p=0.034) and for >20-mm tumors (p=0.016). Post-therapeutic survival among elderly patients might be better with surgery than with SBRT in NSCLC patients with tumors >20 mm. Copyright © 2014 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

New red Y 0.85Bi 0.1Eu 0.05V 1-yM yO 4 (M=Nb, P) phosphors for light-emitting diodes

NASA Astrophysics Data System (ADS)

Wang, Yuhua; Sun, Yunkui; Zhang, Jiachi; Ci, Zhipeng; Zhang, Zhiya; Wang, Lei

2008-06-01

The Y 0.85Bi 0.1Eu 0.05V 1-yM yO 4 (M=Nb, P) as new near-ultraviolet excited phosphors were synthesized and their luminescence properties under 365 nm excitation were investigated in detail. It indicated that by doping small amount of P 5+ into V 5+ sites, the excitation intensity of charge transfer (CT) band of Bi-O (330-400 nm) was greatly improved. By substituting Nb 5+ for V 5+, both the CT bands of Bi-O and Eu-O (240-320 nm) were significantly enhanced. As a result, the emission intensity of Y 0.85Bi 0.1Eu 0.05V 1-yM yO 4 (M=Nb, P) could be improved about 90% by doping 5 mol% P 5+ and 110% by doping 5 mol% Nb 5+. Comparing with the commercial Y 2O 2S:Eu 3+ phosphors, the Y 0.85Bi 0.1Eu 0.05V 0.95M 0.05O 4 (M=Nb, P) phosphors exhibited excellent color purity and much higher brightness. The results showed that these Y 0.85Bi 0.1Eu 0.05V 1-yM yO 4 (M=Nb, P) phosphors could be considered as promising red phosphors for application in LED.

Locoregional treatment and overall survival of men with T1a,b,cN0M0 breast cancer: A population-based study.

PubMed

Leone, José Pablo; Leone, Julieta; Zwenger, Ariel Osvaldo; Iturbe, Julián; Leone, Bernardo Amadeo; Vallejo, Carlos Teodoro

2017-01-01

Male breast cancer (MaBC) is an understudied disease; information about locoregional treatment and outcomes in patients with early stage is unknown. We aimed to analyse patient characteristics, locoregional treatment and overall survival (OS) of T1a,b,cN0M0 male breast cancer. We evaluated men with T1a,b,cN0M0 breast cancer reported to Surveillance, Epidemiology, and End Results program from 1988 to 2012. Univariate and multivariate analyses were performed to determine the effect of each variable on OS. We included 1263 patients. Median age was 66 years (range 27-103). Median follow-up was 62 months (range 1-294). OS at 5 and 10 years were 85.1% and 66.5%, respectively. Distribution according to tumour sub-stage was: T1a 6.5%, T1b 20.7% and T1c 72.8%. Mastectomy was performed in >74% of patients of each tumour size group and overall 44.1% had >5 lymph nodes examined (LNE). Univariate analysis showed that patients with T1c, no surgery and 0 LNE had worse prognosis. In multivariate analysis, older age (hazard ratio [HR] 11.09), grade 3/4 tumours (HR 1.7), no surgery (HR 3.3), 0 LNE (HR 5.1) and unmarried patients (HR 1.7) had significantly shorter OS. There were no differences in OS between breast conservation versus mastectomy and 1-5 LNE versus > 5 LNE. Men with early breast cancer have a favourable OS. However, older age, higher grade, no breast surgery, no LNE and unmarried status emerged as poor prognostic characteristics. Efforts to decrease the high rates of mastectomy and extensive LNE should be taken given similar OS observed with breast conservation and 1-5 LNE, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Auroral excitation of the N2 2P(0,0) and VK(0,9) bands

NASA Technical Reports Server (NTRS)

Solomon, Stanley C.

1989-01-01

The low-energy secondary electron flux caused by auroral electron precipitation is examined using data from the Atmosphere Explorer C satellite. An energetic electron transport algorithm is used to compute the differential electron flux produced by measured primaries. Emissions of N2 in the 2P(0,0) band at 337 nm and the VK(0,9) band at 335 nm predicted by the model are compared with photometric observation of their combined volume emission rate altitude profile made by the visible airglow experiment. Reasonable correspondence between model and measurement is obtained. Ratios of emissions at 337 nm and 630 nm to the N2(+) 1N(0,0) band at 428 nm are also studied. It is concluded that the 337/428 nm ratio responds to changes in the characteristic energy of primary auroral electrons only insofar as part of the 337 nm brightness is due to N2 VK(0,9) emission. The 630/428 nm ratio, which is strongly dependent on characteristic energy, also varies significantly with changes in atomic oxygen density.

High Temperature Operation of Al 0.45Ga 0.55N/Al 0.30Ga 0.70 N High Electron Mobility Transistors

DOE PAGES

Baca, Albert G.; Armstrong, Andrew M.; Allerman, Andrew A.; ...

2017-08-01

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that have a bandgap greater than ~3.4 eV, beyond that of GaN and SiC, and are promising candidates for RF and power applications. Long-channel Al xGa 1-xN HEMTs with x = 0.3 in the channel have been built and evaluated across the -50°C to +200°C temperature range. Room temperature drain current of 70 mA/mm, absent of gate leakage, and with a modest -1.3 V threshold voltage was measured. A very large I on/I off current ratio, greater than 10 8 was demonstrated over the entire temperaturemore » range, indicating that off-state leakage is below the measurement limit even at 200°C. Finally, combined with near ideal subthreshold slope factor that is just 1.3× higher than the theoretical limit across the temperature range, the excellent leakage properties are an attractive characteristic for high temperature operation.« less

High Temperature Operation of Al 0.45Ga 0.55N/Al 0.30Ga 0.70 N High Electron Mobility Transistors

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

Baca, Albert G.; Armstrong, Andrew M.; Allerman, Andrew A.

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that have a bandgap greater than ~3.4 eV, beyond that of GaN and SiC, and are promising candidates for RF and power applications. Long-channel Al xGa 1-xN HEMTs with x = 0.3 in the channel have been built and evaluated across the -50°C to +200°C temperature range. Room temperature drain current of 70 mA/mm, absent of gate leakage, and with a modest -1.3 V threshold voltage was measured. A very large I on/I off current ratio, greater than 10 8 was demonstrated over the entire temperaturemore » range, indicating that off-state leakage is below the measurement limit even at 200°C. Finally, combined with near ideal subthreshold slope factor that is just 1.3× higher than the theoretical limit across the temperature range, the excellent leakage properties are an attractive characteristic for high temperature operation.« less

Microstructure and thermal stability of Cu/Zr0.3Al0.7N/Zr0.2Al0.8N/Al34O60N6 cermet-based solar selective absorbing coatings

NASA Astrophysics Data System (ADS)

Meng, Jian-ping; Guo, Rui-rui; Li, Hu; Zhao, Lu-ming; Liu, Xiao-peng; Li, Zhou

2018-05-01

Solar selective absorbing coatings play a valuable role in photo-thermal conversion for high efficiency concentrating solar power systems (CSP). In this paper, a novel Cu/Zr0.3Al0.7N/Zr0.2Al0.8N/Al34O60N6 cermet-based solar selective absorbing coating was successfully deposited by ion beam assisted deposition. The optical properties, microstructure and element distribution in depth were investigated by spectroscopic ellipsometry, UV-vis-NIR spectrophotometer, transmission electron microscope (TEM) and Auger electron spectroscopy (AES), respectively. A high absorptance of 0.953 and a low thermal emittance of 0.079 at 400 °C are obtained by the integral computation according to the whole reflectance from 300 nm to 28,800 nm. After annealing treatment at 400 °C (in vacuum) for 192 h, the deposited coating exhibits the high thermal stability. Whereas, the photothermal conversion efficiency decreases from 12.10 to 6.86 due to the emittance increase after annealing at 600 °C for 192 h. Meanwhile, the nitrogen atom in the Zr0.3Al0.7N sub-layer diffuses toward the adjacent sub-layer due to the spinodal decomposition of metastable c-ZrAlN and the phase transition from c-AlN to h-AlN, which leads to the composition of the Zr0.3Al0.7N sub-layer deviates the initial design. This phenomenon has a guide effect for the thermal-stability improvement of cermet coatings. Additionally, a serious diffusion between copper and silicon substrate also contributes to the emittance increase.

Outcomes of radiofrequency ablation (RFA) and CO2 laser for early glottic cancer.

PubMed

Shuang, Yu; Li, Chao; Zhou, Xuan; Huang, Yongwang; Zhang, Lun

2016-01-01

In the present study, the voice and functional outcomes of radiofrequency ablation (RFA) and CO2 laser for early glottic cancer were evaluated. One hundred sixty eight patients with early glottic cancer from October 2007 to June 2015 were included. Ninety-seven patients underwent RFA and seventy-one patients underwent CO2 laser. The operation time and score of visual analog scale (VAS) for pain on the second day after surgery were recorded. The electronic laryngoscopy was performed at one week, one month and three months of postoperation. The operation time in RFA was shorter than that in CO2 laser (8.52±1.43min vs. 11.76±1.67min, P<0.05). There was no statistical difference in VAS scores between two operation methods (2.86±0.52 vs. 2.89±0.68, P>0.05). One month after operation, the mucosal recovery in RFA group was better than that in CO2 laser group (P<0.05). The alterations of acoustic parameters Jitter, Shimmer and HNR at three time points after operation showed statistical significances in both RFA and CO2 laser groups (P<0.05). The significant differences in acoustic parameters between two groups were also observed (P<0.05). There were no differences in three-year survival rate, local recurrence rate, recurrence rate with anterior commissure involvement and postoperative adhesion rate with anterior commissure between the patients with RFA and CO2 laser (P>0.05). No patient underwent tracheotomy and had symptoms of bucking, dyspnea, severe pain, hemoptysis and other serious complications. Both RFA and CO2 laser are safe and effective for the treatment of early glottic cancer. RFA has the advantage of quick voice recovery, low mucosa injury and short operation time, which is worthy for wide clinical application. Copyright © 2016 Elsevier Inc. All rights reserved.

In situ formation of oxygen vacancy in perovskite Sr0.95Ti0.8Nb0.1M0.1O3 (M = Mn, Cr) toward efficient carbon dioxide electrolysis

PubMed Central

Zhang, Jun; Xie, Kui; Wei, Haoshan; Qin, Qingqing; Qi, Wentao; Yang, Liming; Ruan, Cong; Wu, Yucheng

2014-01-01

In this work, redox-active Mn or Cr is introduced to the B site of redox stable perovskite Sr0.95Ti0.9Nb0.1O3.00 to create oxygen vacancies in situ after reduction for high-temperature CO2 electrolysis. Combined analysis using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis confirms the change of the chemical formula from oxidized Sr0.95Ti0.9Nb0.1O3.00 to reduced Sr0.95Ti0.9Nb0.1O2.90 for the bare sample. By contrast, a significant concentration of oxygen vacancy is additionally formed in situ for Mn- or Cr-doped samples by reducing the oxidized Sr0.95Ti0.8Nb0.1M0.1O3.00 (M = Mn, Cr) to Sr0.95Ti0.8Nb0.1M0.1O2.85. The ionic conductivities of the Mn- and Cr-doped titanate improve by approximately 2 times higher than bare titanate in an oxidizing atmosphere and 3–6 times higher in a reducing atmosphere at intermediate temperatures. A remarkable chemical accommodation of CO2 molecules is achieved on the surface of the reduced and doped titanate, and the chemical desorption temperature reaches a common carbonate decomposition temperature. The electrical properties of the cathode materials are investigated and correlated with the electrochemical performance of the composite electrodes. Direct CO2 electrolysis at composite cathodes is investigated in solid-oxide electrolyzers. The electrode polarizations and current efficiencies are observed to be significantly improved with the Mn- or Cr-doped titanate cathodes. PMID:25403738

Phase I/II study of hypofractioned radiation with three-dimensional conformal radiotherapy for clinical T3-4N0-1M0 stage esophageal carcinoma.

PubMed

Song, Y-P; Ma, J-B; Hu, L-K; Zhou, W; Chen, E-C; Zhang, W

2011-02-01

Compared to conventional fractionated-dose radiotherapy, high hypofractionated-dose radiotherapy could yield tumoricidal effects. However, few clinical trials of hypofractionated radiotherapy in loco-regionally advanced incurable esophageal cancer at present have yet been performed. The purpose of the current study was to evaluate the efficacy and toxicity of hypofractioned radiation with three-dimensional conformal radiotherapy for clinical T3-4N0-1M0 stage esophageal carcinoma. From September 2003 to December 2005, 45 patients with locally advanced esophageal carcinoma were grouped and received three-dimensional conformal hypofractioned radiotherapy (3D-CRT) whose fractionated dose was gradually increase per group. Radiotherapy was administered to a total dose of from 50 to 54 Gy (fractionated dose of from 3.0 to 6.0 Gy, 3 times weekly), over a 3-4 week period. And patients received 4 cycles chemotherapy. The median follow-up period for survivors was 38 months. Treatment tolerance rate was 78.8% with daily dose of from 3 to 5 Gy. There are 21.2% patients occurring Grade ≥ 3 acute toxicities. But patients couldn't tolerate daily dose of 6 Gy (55.6%). The 1-year, 2-year and 3-year local control rates were 62%, 49% and 39% respectively. And the 1-year, 2-year and 3-year overall survival rates were 34%, 21% and 9% respectively. The median overall survival time was 17 months. At the time of following up, 13 patients (31.0%) had occurred esophageal late complications, with mainly esophageal perforation, hemorrhage or stenosis, including initial stenosis aggravation. Therefore hypofractionated irradiation was thought to be feasible for clinical T3-4N0-1M0 stage esophageal carcinoma. And daily dose of ≤5 Gy was comparatively suitable in hypofractionated irradiation for esophageal carcinoma, and the patients tolerated well. But further research was in need also.

In0.15Ga0.85N visible-light metal-semiconductor-metal photodetector with GaN interlayers deposited by pulsed NH3

NASA Astrophysics Data System (ADS)

Wang, Hongxia; Zhang, Xiaohan; Wang, Hailong; Lv, Zesheng; Li, Yongxian; Li, Bin; Yan, Huan; Qiu, Xinjia; Jiang, Hao

2018-05-01

InGaN visible-light metal-semiconductor-metal photodetectors with GaN interlayers deposited by pulsed NH3 were fabricated and characterized. By periodically inserting the GaN thin interlayers, the surface morphology of InGaN active layer is improved and the phase separation is suppressed. At 5 V bias, the dark current reduced from 7.0 × 10-11 A to 7.0 × 10-13 A by inserting the interlayers. A peak responsivity of 85.0 mA/W was measured at 420 nm and 5 V bias, corresponding to an external quantum efficiency of 25.1%. The insertion of GaN interlayers also lead to a sharper spectral response cutoff.

Infrared Spectra of M^+(2-AMINO-1-PHENYL ETHANOL)(H_2O)_{n=0-2}Ar (M=Na, K)

NASA Astrophysics Data System (ADS)

Nicely, Amy L.; Lisy, James M.

2009-06-01

A balance of competing electrostatic and hydrogen bonding interactions directs the structure of hydrated gas-phase cluster ions. Because of this, a biologically relevant model of cluster structures should include the effects of surrounding water molecules and metal ions such as sodium and potassium, which are found in high concentrations in the bloodstream. The molecule 2-amino-1-phenyl ethanol (APE) serves as a model for the neurotransmitters ephedrine and adrenaline. The neutral APE molecule contains an internal hydrogen bond between the amino and hydroxyl groups. In the M^+(APE) complex, the cation can either interrupt the internal hydrogen bond or position itself above the phenyl group, leaving the internal hydrogen bond intact. The former is preferred based on DFT calculations (B3LYP/6-31+G*) for both K^+ and Na^+ across the entire range from 0-400K, but infrared photodissociation (IRPD) spectra indicate a preference for the latter configuration at low temperatures. The IRPD spectra of M^+(H_2O)_{n=1-2} and M^+(H_2O)_{n=0-2}Ar (M=Na, K) will be presented along with parallel DFT and thermodynamics calculations to assist with the identification of the isomers present in each experiment.

N-substituted 8-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecanes as σ receptor ligands with potential neuroprotective effects.

PubMed

Banister, Samuel D; Manoli, Miral; Barron, Melissa L; Werry, Eryn L; Kassiou, Michael

2013-10-01

Several libraries of similarly N-substituted 8-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecanes (9), N-methyl-8-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecanes (14), and N-methyl-11-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecan-8-ones (13) were synthesised and screened against a panel of CNS targets in order to develop structure-affinity relationships for cage-modified trishomocubane σ receptor ligands based on the N-substituted 4-azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11)]dodecan-3-ol (8) scaffold. In general, compared to the corresponding 4-azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11)]dodecan-3-ols, compounds of type 9 were potent σ receptor ligands with low levels of subtype selectivity, while the corresponding N-methyl-8-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecanes showed reduced affinity but greater selectivity for σ2 receptors. The N-methyl-11-aminopentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecan-8-ones demonstrated the poorest σ receptor affinities, suggesting that 4-azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11)]dodecan-3-ols interact with σ receptors in the bridged hemiaminal form rather than as the non-transannular, aminoketone tautomers. Several compounds of type 8, 9, and 14 were assessed for their ability to inhibit nitric oxide release in vitro, and demonstrated comparable or greater efficacy than 4-phenyl-1-(4-phenylbutyl)piperidine (PPBP), an established neuroprotective σ ligand with NOS inhibitory activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evidence-based practice: management of glottic cancer.

PubMed

Hartl, Dana M

2012-10-01

The main issue in the management of glottic squamous cell carcinoma, as for all cancers, is adequate disease control while optimizing functional outcomes and minimizing morbidity. This is true for early-stage disease as for advanced tumors. This article evaluates the current evidence for the diagnostic and pretherapeutic workup for glottic squamous cell carcinoma and the evidence concerning different treatment options for glottic carcinoma, from early-stage to advanced-stage disease. Copyright © 2012 Elsevier Inc. All rights reserved.

Valence, exchange interaction, and location of Mn ions in polycrystalline M n x G a 1 - x N ( x ≤ 0.04 )

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

Furrer, A.; Kramer, K. W.; Podlesnyak, A.

In this paper, we present an experimental study for polycrystalline samples of the diluted magnetic semiconductormore » $$\\mathrm{M}{\\mathrm{n}}_{x}\\mathrm{G}{\\mathrm{a}}_{1{-}x}\\mathrm{N}(x{\\le}0.04)$$ in order to address some of the existing controversial issues. X-ray and neutron diffraction, x-ray absorption near-edge structure, and electron paramagnetic resonance experiments were used to characterize the structural, electronic, and magnetic properties of the samples, and inelastic neutron scattering was employed to determine the magnetic excitations associated with Mn monomers and dimers. Our main conclusions are as follows: (i) The valence of the Mn ions is $2+$. (ii) The $$\\mathrm{M}{\\mathrm{n}}^{2+}$$ ions experience a substantial single-ion axial anisotropy with parameter D = 0.027(3) meV. (iii) Nearest-neighbor $$\\mathrm{M}{\\mathrm{n}}^{2+}$$ ions are coupled antiferromagnetically. Finally, the exchange parameter $$J={-}0.140(7)\\mathrm{meV}$$ is independent of the Mn content $x$; i.e., there is no evidence for hole-induced modifications of $J$ towards a potentially high Curie temperature postulated in the literature.« less

Valence, exchange interaction, and location of Mn ions in polycrystalline M n x G a 1 - x N ( x ≤ 0.04 )

DOE PAGES

Furrer, A.; Kramer, K. W.; Podlesnyak, A.; ...

2018-04-10

In this paper, we present an experimental study for polycrystalline samples of the diluted magnetic semiconductormore » $$\\mathrm{M}{\\mathrm{n}}_{x}\\mathrm{G}{\\mathrm{a}}_{1{-}x}\\mathrm{N}(x{\\le}0.04)$$ in order to address some of the existing controversial issues. X-ray and neutron diffraction, x-ray absorption near-edge structure, and electron paramagnetic resonance experiments were used to characterize the structural, electronic, and magnetic properties of the samples, and inelastic neutron scattering was employed to determine the magnetic excitations associated with Mn monomers and dimers. Our main conclusions are as follows: (i) The valence of the Mn ions is $2+$. (ii) The $$\\mathrm{M}{\\mathrm{n}}^{2+}$$ ions experience a substantial single-ion axial anisotropy with parameter D = 0.027(3) meV. (iii) Nearest-neighbor $$\\mathrm{M}{\\mathrm{n}}^{2+}$$ ions are coupled antiferromagnetically. Finally, the exchange parameter $$J={-}0.140(7)\\mathrm{meV}$$ is independent of the Mn content $x$; i.e., there is no evidence for hole-induced modifications of $J$ towards a potentially high Curie temperature postulated in the literature.« less

Web thickness determines the therapeutic effect of endoscopic keel placement on anterior glottic web.

PubMed

Chen, Jian; Shi, Fang; Chen, Min; Yang, Yue; Cheng, Lei; Wu, Haitao

2017-10-01

This work is a retrospective analysis to investigate the critical risk factor for the therapeutic effect of endoscopic keel placement on anterior glottic web. Altogether, 36 patients with anterior glottic web undergoing endoscopic lysis and silicone keel placement were enrolled. Their voice qualities were evaluated using the voice handicap index-10 (VHI-10) questionnaire, and improved significantly 3 months after surgery (21.53 ± 3.89 vs 9.81 ± 6.68, P < 0.0001). However, 10 (27.8%) cases had web recurrence during the at least 1-year follow-up. Therefore, patients were classified according to the Cohen classification or web thickness, and the recurrence rates were compared. The distribution of recurrence rates for Cohen type 1 ~ 4 were 28.6, 16.7, 33.3, and 40%, respectively. The difference was not statistically significant (P = 0.461). When classified by web thickness, only 2 of 27 (7.41%) thin type cases relapsed whereas 8 of 9 (88.9%) cases in the thick group reformed webs (P < 0.001). These results suggest that the therapeutic outcome of endoscopic keel placement mostly depends on the web thickness rather than the Cohen grades. Endoscopic lysis and keel placement is only effective for cases with thin glottic webs. Patients with thick webs should be treated by other means.

Polar and semipolar GaN/Al0.5Ga0.5N nanostructures for UV light emitters

NASA Astrophysics Data System (ADS)

Brault, J.; Rosales, D.; Damilano, B.; Leroux, M.; Courville, A.; Korytov, M.; Chenot, S.; Vennéguès, P.; Vinter, B.; De Mierry, P.; Kahouli, A.; Massies, J.; Bretagnon, T.; Gil, B.

2014-06-01

AlxGa1-xN-based ultra-violet (UV) light emitting diodes (LEDs) are seen as the best solution for the replacement of traditional mercury lamp technology. By adjusting the Al concentration, a large emission spectrum range from 360 nm (GaN) down to 200 nm (AlN) can be covered. Owing to the large density of defects typically present in AlxGa1-xN materials usually grown on sapphire substrates, LED efficiencies still need to be improved. Taking advantage of the 3D carrier confinement, quantum dots (QDs) are among the solutions currently under investigation to improve the performances of UV LEDs. The objectives of this work are to present and discuss the morphological and optical properties of GaN nanostructures grown by molecular beam epitaxy on the (0 0 0 1) and the (11-22) orientations of Al0.5Ga0.5N. In particular, the dependence of the morphological properties of the nanostructures on the growth conditions and the surface orientation will be presented. The optical characteristics as a function of the nanostructure design (size, shape and dimensionality) will also be shown and discussed. The electroluminescence characteristics of a first series of QD-based GaN/Al0.5Ga0.5N LEDs grown on the polar (0 0 0 1) plane will be investigated.

Structural and electrochemical properties of the doped spinels Li 1.05M 0.02Mn 1.98O 3.98N 0.02 (M = Ga 3+, Al 3+, or Co 3+; N = S 2- or F -) for use as cathode material in lithium batteries

NASA Astrophysics Data System (ADS)

Amaral, Fábio A.; Bocchi, Nerilso; Brocenschi, Ricardo F.; Biaggio, Sonia R.; Rocha-Filho, Romeu C.

The doped and milled spinels Li 1.05M 0.02Mn 1.98O 3.98N 0.02 (M = Ga 3+, Al 3+ or Co 3+; N = S 2- or F -) are studied aiming at obtaining an improved charge/discharge cycling performance. These spinels are prepared by a solid-state reaction among the precursors ɛ-MnO 2, LiOH, and the respective oxide/salt of the doping ions at 750 °C for 72 h and milled for 30 min. The obtained spinels are characterized by XRD, SEM, and determinations of the average manganese valence n. In the charge and discharge tests, the doped spinels present outstanding initial values of the specific discharge capacity C (117-126 mA h g -1), decreasing in the following order: C(Li 1.05Al 0.02Mn 1.98S 3.02O 3.98) > C(Li 1.05Al 0.02Mn 1.98F 3.02O 3.98) > C(Li 1.05Ga 0.02Mn 1.98S 3.02O 3.98) > C(Li 1.05Ga 0.02Mn 1.98F 3.02O 3.98) > C(Li 1.05Co 0.02Mn 1.98S 3.02O 3.98) > C(Li 1.05Co 0.02Mn 1.98F 3.02O 3.98). The doped spinel Li 1.05Ga 0.02Mn 1.98S 3.02O 3.98 presents an excellent electrochemical performance, with a low capacity loss even after 300 charge and discharge cycles (from 120 to 115 mA h g -1 or 4%).

Landscape evolution models using the stream power incision model show unrealistic behavior when m / n equals 0.5

NASA Astrophysics Data System (ADS)

Kwang, Jeffrey S.; Parker, Gary

2017-12-01

Landscape evolution models often utilize the stream power incision model to simulate river incision: E = KAmSn, where E is the vertical incision rate, K is the erodibility constant, A is the upstream drainage area, S is the channel gradient, and m and n are exponents. This simple but useful law has been employed with an imposed rock uplift rate to gain insight into steady-state landscapes. The most common choice of exponents satisfies m / n = 0.5. Yet all models have limitations. Here, we show that when hillslope diffusion (which operates only on small scales) is neglected, the choice m / n = 0.5 yields a curiously unrealistic result: the predicted landscape is invariant to horizontal stretching. That is, the steady-state landscape for a 10 km2 horizontal domain can be stretched so that it is identical to the corresponding landscape for a 1000 km2 domain.

Temperature characteristics of SAW resonators on Sc0.26Al0.74N/polycrystalline diamond heterostructures

NASA Astrophysics Data System (ADS)

Sinusía Lozano, M.; Chen, Z.; Williams, Oliver A.; Iriarte, G. F.

2018-07-01

Surface acoustic wave (SAW) resonators have been fabricated on a 2 μm scandium aluminium nitride (ScAlN) film deposited by means of pulsed-DC reactive magnetron sputtering on a 5.8 μm polycrystalline diamond substrate. Thin film characterization comprised of the assessment of the thin film texture by means of x-ray diffraction (XRD) measurements, reporting highly c-axis oriented ScAlN thin films with a full width at half maximum (FWHM) of the ω-θ scans below 2°. Compositional and piezoelectric analyses of the thin films synthesized with the sputtering parameters used in this work, namely a sputtering power of 700 W and a synthesis pressure of 0.53 Pa, have reported a thin film composition of Sc0.26Al0.74N together with a piezoelectric d33 constant of ‑11 pC/N. Finally, a SAW resonator has been characterized using a vector network analyser (VNA) under various substrate temperature conditions with two iterations. The resulting temperature coefficient of frequency (TCF) values show a highly linear behaviour within two temperature ranges, namely from 20 K to room temperature (300 K) (‑12.5 ppm/K) as well as from 300 K up to 450 K (‑34.6 ppm/K).

Medición de los parámetros cosmológicos q0, ΩM, y ΩΛ, usando supernovas de Tipo Ia distantes

NASA Astrophysics Data System (ADS)

Clocchiatti, A.; High-Z Sne Search Team

Las supernovas de tipo Ia son una herramienta de gran precisión para la medición de distancias de interés cosmológico. Los métodos recientes de calibración de su luminosidad intrínseca, que hacen uso de la forma de las curvas de luz en varios colores y permiten diferenciar entre supernovas distantes, intrínsecamente débiles, u oscurecidas por extinción, reducen la dispersión del método que las asume de magnitud absoluta constante de 0.50 mag a 0.15 mag, e incrementa el valor de la constante de Hubble de ~55 km s-1 Mpc-1, a 65 km s-1 Mpc-1. A partir de la calibración de las supernovas cercanas, con redshifts menores que 0.1, se pueden obtener distancias precisas a supernovas que explotan a alto redshift. Hemos aplicado estos métodos a 16 supernovas con 0.16 < Z < 0.97, encontrando que sus distancias son, en promedio, entre 10% y 13% (dependiendo del método empleado) mayores que las que uno esperaría en un universo con poca masa (Ω = 0.2), sin una constante cosmológica. Todos los métodos de ajuste de curvas de luz, y selección de subgrupos de la muestra de supernovas observadas, favorecen consistentemente modelos del universo que se expanden eternamente y que tienen una constante cosmológica positiva (ΩΛ > 0), y una aceleración de la expansión al presente (q0 < 0). Hay distintas fuentes de posibles errores sistemáticos que merecen ser analizadas, entre ellas: evolución de la metalicidad y estrellas progenitoras, extinción, bias en la elección de la muestra, amplificación por gravitational lensing, y contaminación de la muestra. Ninguno de estos efectos alcanza para reconciliar los datos con ΩΛ = 0, o q0 > 0.

Al 0.85Ga 0.15N/Al 0.70Ga 0.30N High Electron Mobility Transistors with Schottky Gates and Large On/Off Current Ratio over Temperature

DOE PAGES

Baca, Albert G.; Klein, Brianna A.; Allerman, Andrew A.; ...

2017-12-09

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that are promising candidates for RF and power applications. Long-channel Al xGa 1-xN HEMTs with x = 0.7 in the channel have been built and evaluated across the -50°C to +200°C temperature range. These devices achieved room temperature drain current as high as 46 mA/mm and were absent of gate leakage until the gate diode forward bias turn-on at ~2.8 V, with a modest -2.2 V threshold voltage. A very large I on/I off current ratio, of 8 × 10 9 was demonstrated. A near idealmore » subthreshold slope that is just 35% higher than the theoretical limit across the temperature range was characterized. The ohmic contact characteristics were rectifying from -50°C to +50°C and became nearly linear at temperatures above 100°C. An activation energy of 0.55 eV dictates the temperature dependence of off-state leakage.« less

Al 0.85Ga 0.15N/Al 0.70Ga 0.30N High Electron Mobility Transistors with Schottky Gates and Large On/Off Current Ratio over Temperature

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

Baca, Albert G.; Klein, Brianna A.; Allerman, Andrew A.

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that are promising candidates for RF and power applications. Long-channel Al xGa 1-xN HEMTs with x = 0.7 in the channel have been built and evaluated across the -50°C to +200°C temperature range. These devices achieved room temperature drain current as high as 46 mA/mm and were absent of gate leakage until the gate diode forward bias turn-on at ~2.8 V, with a modest -2.2 V threshold voltage. A very large I on/I off current ratio, of 8 × 10 9 was demonstrated. A near idealmore » subthreshold slope that is just 35% higher than the theoretical limit across the temperature range was characterized. The ohmic contact characteristics were rectifying from -50°C to +50°C and became nearly linear at temperatures above 100°C. An activation energy of 0.55 eV dictates the temperature dependence of off-state leakage.« less

Stability of levothyroxine sodium 0.4 microg/mL in 0.9% sodium chloride injection.

PubMed

Stadalman, Kelli A; Kelner, Michael J; Box, Kevin; Dominguez, Alex; Rigby, Joseph F

2009-12-01

Intravenous levothyroxine therapy decreases vasopressor requirements and prevents cardiovascular collapse in hemodynamically unstable patients eligible for organ donation. The stability of levothyroxine when used in this manner is unknown. To determine the stability of levothyroxine solution for intravenous use at a concentration of 0.4 microg/mL diluted in 0.9% sodium chloride. Triplicate sample sets were prepared by reconstituting levothyroxine 200 microg for injection with 5 mL of 0.9% sodium chloride with further dilution in 500 mL of 0.9% sodium chloride. One sample set was protected from light and the other was left unprotected. Both sample sets were stored at room temperature, and samples from each were analyzed for initial concentration and 4, 8, 12, and 24 hours later. Levothyroxine sodium 0.4 microg/mL in 500 mL 0.9% sodium chloride is stable for 24 hours at room temperature when protected from light.

ECO2N V2.0

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

Pan, Lehua; Spycher, Nicolas; Doughty, Christine

2015-02-01

ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300oC whereas V1.0 can only be used for temperatures below about 110oC. V2.0 includes a comprehensive description of the thermodynamic and thermophysical properties of H2O - NaCl - CO2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10 °C 0 accounts for the effects of water on the thermophysical properties of the CO2-rich phase, which was ignored in V1.0, using a model consistent with the solubility models developed by Spycher and Pruess (2005, 2010). In terms of solubility models, V2.0 uses the same model for partitioning of mass components among the different phases (Spycher and Pruess, 2005) as V1.0 for the low temperature range (<99oC) but uses a new model (Spycher and Pruess, 2010) for the high temperature range (>109oC). In the transition range (99-109oC), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO2-rich) phase, as well as two-phase (brine-CO2) mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. Note that the model cannot be applied to subcritical conditions that involves both liquid and gaseous CO2

Glottic airway gain after 'suture arytenoid laterofixation' in bilateral vocal cord paralysis.

PubMed

Korkmaz, Mehmet Hakan; Bayır, Ömer; Tatar, Emel Çadallı; Saylam, Güleser; Öcal, Bülent; Keseroğlu, Kemal; Özdek, Ali

2015-09-01

This method is an easy, non-expensive, and effective technique in bilateral vocal cord paralysis to improve glottic airway and clinical performance. To evaluate the effectiveness of 'suture arytenoid laterofixation' surgery in bilateral vocal cord paralysis. A retrospective analysis of patients' medical history undergoing 'suture arytenoid laterofixation' surgery for bilateral vocal cord paralysis. This technique was applied under general anesthesia with both microlaryngoscopy and video-monitoring. Two 16 g needles and one 1/0 nylon thread were used for the procedure with 1 cm skin incision; no tracheotomy or tissue excision was required. Pre-post-operative photographs of the glottic region were taken from the endoscopic records, and the areas of rima glottis openings were calculated with the Image-J programme. Forty-seven patients were analyzed. The mean pre-post-operative rima glottis areas were 1.11 ± 0.56 and 2.24 ± 0.93 mm(2), respectively (p < 0.001). Five patients with previous tracheotomy were decannulated within a few days after the operation. In three patients, mild complications developed in the early post-operative period (two laryngeal edemas, one submucosal hematoma). Tracheotomy was performed to only one pregnant patient in the post-operative first day. None of the patients had granulation formation or synechia.

[((H)L)2Fe6(NCMe)m]n+ (m = 0, 2, 4, 6; n = -1, 0, 1, 2, 3, 4, 6): an electron-transfer series featuring octahedral Fe6 clusters supported by a hexaamide ligand platform.

PubMed

Zhao, Qinliang; Harris, T David; Betley, Theodore A

2011-06-01

Using a trinucleating hexaamide ligand platform, the all-ferrous hexanuclear cluster ((H)L)(2)Fe(6) (1) is obtained from reaction of 3 equiv of Fe(2)(Mes)(4) (Mes = 2,4,6-Me(3)C(6)H(2)) with 2 equiv of the ligand ((H)L)H(6). Compound 1 was characterized by X-ray diffraction analysis, (57)Fe Mössbauer, SQUID magnetometry, mass spectrometry, and combustion analysis, providing evidence for an S=6 ground state and delocalized electronic structure. The cyclic voltammogram of [((H)L)(2)Fe(6)](n+) in acetonitrile reveals a rich redox chemistry, featuring five fully reversible redox events that span six oxidation states ([((H)L)(2)Fe(6)](n+), where n=-1→4) within a 1.3 V potential range. Accordingly, each of these species is readily accessed chemically to provide the electron-transfer series [((H)L)(2)Fe(6)(NCMe)(m)][PF(6)](n) (m=0, n=-1 (2); m=2, n=1 (3); m=4, n=2 (4); m=6, n=3 (5); m=6, n=4 (6)). Compounds 2-6 were isolated and characterized by X-ray diffraction, (57)Fe Mössbauer and multinuclear NMR spectroscopy, and combustion analysis. Two-electron oxidation of the tetracationic cluster in 6 by 2 equiv of [NO](+) generates the thermally unstable hexacationic cluster [((H)L)(2)Fe(6)(NCMe)(m)](6+), which is characterized by NMR and (57)Fe Mössbauer spectroscopy. Importantly, several stepwise systematic metrical changes accompany oxidation state changes to the [Fe(6)] core, namely trans ligation of solvent molecules and variation in Mössbauer spectra, spin ground state, and intracluster Fe-Fe separation. The observed metrical changes are rationalized by considering a qualitative, delocalized molecular orbital description, which provides a set of frontier orbitals populated by Fe 3d electrons. © 2011 American Chemical Society

Trial Vocal Fold Injection Predicts Thyroplasty Outcomes in Nonparalytic Glottic Incompetence.

PubMed

Dumberger, Lukas D; Overton, Lewis; Buckmire, Robert A; Shah, Rupali N

2017-04-01

Trial vocal fold injection (TVFI) may be used prior to permanent medialization when voice outcome is uncertain. We aimed to determine whether voice outcomes of TVFI are predictive of, or correlate with outcomes after type I Gore-Tex medialization thyroplasty (GMT) in patients with nonparalytic glottic incompetence (GI). Thirty-five patients with nonparalytic GI who underwent TVFI followed by GMT were retrospectively reviewed. Change in voice-related quality of life (VRQOL) after TVFI was compared to change in VRQOL 3 to 9 months after GMT. Similar comparisons were made for change in glottal function index (GFI) and change in grade, roughness, breathiness, asthenia, and strain (GRBAS). Sample correlation coefficients were calculated. Change in VRQOL after TVFI showed good correlation with change in VRQOL after GMT, r = 0.55. Change in GFI after TVFI showed strong correlation with change in GFI after GMT, r = 0.74. Change in GRBAS after TVFI showed excellent correlation with change in GRBAS after GMT, r = 0.90. The TVFI is a useful tool in nonparalytic GI when outcomes from glottic closure procedures are not clear. Voice outcome measures after TVFI strongly correlate with outcomes from GMT. These data may be used to more confidently counsel patients regarding their predicted outcomes of permanent medialization.

Synthesis, electrochemical investigation and structural analysis of doped Li[Ni0.6Mn0.2Co0.2-xMx]O2 (x = 0, 0.05; M = Al, Fe, Sn) cathode materials

NASA Astrophysics Data System (ADS)

Eilers-Rethwisch, Matthias; Winter, Martin; Schappacher, Falko Mark

2018-05-01

Layered Ni-rich Li[Ni0.6Mn0.2Co0.2-xMx]O2 cathode materials (x = 0, 0.05; M = Al, Fe, Sn) are synthesized via a co-precipitation synthesis route and the effect of dopants on the structure and electrochemical performance is investigated. All synthesized materials show a well-defined layered structure of the hexagonal α-NaFeO2 phase investigated by X-ray diffraction (XRD). Undoped LiNi0.6Mn0.2Co0.2O2 exhibits a discharge capacity of 170 mAh g-1 in Li-metal 2032 coin-type cells. Doped materials reach lower capacities between 145 mAh g-1 for Al and 160 mAh g-1 for Sn. However, all doped materials prolong the cycle life by up to 20%. Changes of the lattice parameter before and after delithiation yield information about structural stability. A smaller repulsion of the transition metal layer during delithiation in the Sn-doped material leads to a smaller expansion of the unit cell, which results in enhanced structural stability of the material. The improved structural stability of Sn-doped NMC cathode active material is proven by thermal investigations with the help of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).

Calculations of long-range three-body interactions for He(n0λS )-He(n0λS )-He(n0'λL )

NASA Astrophysics Data System (ADS)

Yan, Pei-Gen; Tang, Li-Yan; Yan, Zong-Chao; Babb, James F.

2018-04-01

We theoretically investigate long-range interactions between an excited L -state He atom and two identical S -state He atoms for the cases of the three atoms all in spin-singlet states or all in spin-triplet states, denoted by He(n0λS )-He(n0λS )-He(n0'λL ), with n0 and n0' principal quantum numbers, λ =1 or 3 the spin multiplicity, and L the orbital angular momentum of a He atom. Using degenerate perturbation theory for the energies up to second-order, we evaluate the coefficients C3 of the first-order dipolar interactions and the coefficients C6 and C8 of the second-order additive and nonadditive interactions. Both the dipolar and dispersion interaction coefficients, for these three-body degenerate systems, show dependences on the geometrical configurations of the three atoms. The nonadditive interactions start to appear in second-order. To demonstrate the results and for applications, the obtained coefficients Cn are evaluated with highly accurate variationally generated nonrelativistic wave functions in Hylleraas coordinates for He(1 1S ) -He(1 1S ) -He(2 1S ) , He(1 1S ) -He(1 1S ) -He(2 1P ) , He(2 1S ) -He(2 1S ) -He(2 1P ) , and He(2 3S ) -He(2 3S ) -He(2 3P ) . The calculations are given for three like nuclei for the cases of hypothetical infinite mass He nuclei, and of real finite mass 4He or 3He nuclei. The special cases of the three atoms in equilateral triangle configurations are explored in detail, and for the cases in which one of the atoms is in a P state, we also present results for the atoms in an isosceles right triangle configuration or in an equally spaced collinear configuration. The results can be applied to construct potential energy surfaces for three helium atom systems.

Defect structure of high temperature hydride vapor phase epitaxy-grown epitaxial (0 0 0 1) AlN/sapphire using growth mode modification process

NASA Astrophysics Data System (ADS)

Su, Xujun; Zhang, Jicai; Huang, Jun; Zhang, Jinping; Wang, Jianfeng; Xu, Ke

2017-06-01

Defect structures were investigated by transmission electron microscopy for AlN/sapphire (0 0 0 1) epilayers grown by high temperature hydride vapor phase epitaxy using a growth mode modification process. The defect structures, including threading dislocations, inversion domains, and voids, were analyzed by diffraction contrast, high-resolution imaging, and convergent beam diffraction. AlN film growth was initiated at 1450 °C with high V/III ratio for 8 min. This was followed by low V/III ratio growth for 12 min. The near-interfacial region shows a high density of threading dislocations and inversion domains. Most of these dislocations have Burgers vector b = 1/3〈1 1 2 0〉 and were reduced with the formation of dislocation loops. In the middle range 400 nm < h < 2 μm, dislocations gradually aggregated and reduced to ∼109 cm-2. The inversion domains have a shuttle-like shape with staggered boundaries that deviate by ∼ ±5° from the c axis. Above 2 μm thickness, the film consists of isolated threading dislocations with a total density of 8 × 108 cm-2. Most of threading dislocations are either pure edge or mixed dislocations. The threading dislocation reduction in these films is associated with dislocation loops formation and dislocation aggregation-interaction during island growth with high V/III ratio.

Uniport versus multiport video-assisted thoracoscopic surgery in the perioperative treatment of patients with T1-3N0M0 non-small cell lung cancer: a systematic review and meta-analysis.

PubMed

Yang, Xinyu; Li, Ming; Yang, Xiaodong; Zhao, Mengnan; Huang, Yiwei; Dai, Xiyu; Jiang, Tian; Feng, Mingxiang; Zhan, Cheng; Wang, Qun

2018-04-01

Uniport video-assisted thoracoscopic surgery (VATS) has emerged as a less invasive approach for the treatment of non-small cell lung cancer (NSCLC). However, whether uniport VATS has more potential advantages over multiport VATS remains controversial. This meta-analysis aimed to compare the perioperative efficacy of uniport and multiport VATS for T1-3N0M0 NSCLC. An electronic and manual search of literature published before 1st October 2017 was conducted using PubMed, Embase, Web of Science, and the Wiley Online library. The effective values of dichotomous variables or continuous variables were estimated by odds ratios (OR) or by standardized mean differences (SMD) with 95% confidence intervals (CIs) respectively. Eleven relevant observational studies were included for meta-analysis. Results demonstrated that patients in the uniport group had a significant reduction in the duration of postoperative drainage (uniport: 4.39±2.48 vs. multiport: 4.99±3.24 days; P=0.003), bleeding volume (97.7±60.0 vs. 116.7±99.7 mL; P=0.006), length of hospital stay (6.3±2.4 vs. 7.0±3.6 days; P<0.001), VAS of postoperative pain (2.53±0.73 vs. 4.22±0.71, P=0.02) and in the overall rate of complications (14.5% vs. 17.5%; P=0.008). There were no significant differences between the two treatment groups with regards to mortality, operative time, the number of dissected lymph nodes or the conversion rate. Uniport VATS might have represent a preferable option for the treatment of T1-3N0M0 NSCLC, due to its superior perioperative efficacy.

Dielectric and piezoelectric properties of CeO2-added nonstoichiometric (Na0.5K0.5)0.97(Nb0.96Sb0.04)O3 ceramics for piezoelectric energy harvesting device applications.

PubMed

Oh, Youngkwang; Noh, Jungrae; Yoo, Juhyun; Kang, Jinhee; Hwang, Larkhoon; Hong, Jaeil

2011-09-01

In this study, nonstoichiometric (Na(0.5)K(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics were fabricated and their dielectric and piezoelectric properties were investigated according to the CeO(2) addition. In this ceramic composition, CeO(2) addition improved sinterability, electromechanical coupling factor k(p), mechanical quality factor Q(m), piezoelectric constant d(33), and g(33). At the sintering temperature of 1100°C, for the 0.2wt% CeO(2) added specimen, the optimum values of density = 4.359 g/cm(3), k(p) = 0.443, Q(m) = 588, ε(r) = 444, d(33) = 159 pC/N, and g(33) = 35 × 10(-3) V·m/N, were obtained. A piezoelectric energy harvesting device using 0.2 wt% CeO(2)- added lead-free (K(0.5)Na(0.5))(0.97)(Nb(0.96)Sb(0.04))O(3) ceramics and a rectifying circuit for energy harvesting were fabricated and their electrical characteristics were investigated. Under an external vibration acceleration of 0.7 g, when the mass, the frequency of vibration generator, and matching load resistance were 2.4 g, 70 Hz, and 721 Ω, respectively, output voltage and power of piezoelectric harvesting device indicated the optimum values of 24.6 mV(rms) and 0.839 μW, respectively-suitable for application as the electric power source of a ubiquitous sensor network (USN) sensor node.

Study of xCo0.8Ni0.2Fe2O4+(1-x) Pb0.99625 La0.0025Zr0.55Ti0.45O3 magnetoelectric composites

NASA Astrophysics Data System (ADS)

Dipti; Singh, Sangeeta; Juneja, J. K.; Raina, K. K.; Kotnala, R. K.; Prakash, Chandra

2016-06-01

We are reporting here, the studies of the structural, dielectric, ferroelectric and magnetic properties of magnetoelectric composites of La modified lead zirconate titanate (PLZT) and Ni modified cobalt ferrite (CNFO) with compositional formula xCo0.8Ni0.2Fe2O4+(1-x) Pb0.99625La0.0025Zr0.55Ti0.45O3 (x=0.00, 0.05, 0.10, 0.15 and 1.00 by weight) prepared by the solid state reaction method. Coexistence of both the phases in composites was confirmed by X-Ray diffraction technique. The microstructure and average grain size were determined from Scanning Electron Micrograph (SEM) in backscattered mode. Both the phases could be observed clearly. The variations of dielectric properties with frequency and temperature were also studied. P-E and M-H hysteresis measurements were carried. Magnetoelectric coupling (ME) coefficient for samples with x=0.05 and 0.10 were measured as a function of DC magnetic field. Maximum value of ME coefficient (1.2 mV/cm Oe) and piezoelectric coefficient (96 pC/N) for x=0.05 were observed.

Structure and magnetic properties of Sm{sub 3}(Fe{sub 0.85}Cr{sub 0.15}){sub 29}N{sub y} alloys

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

Suzuki, Shunji; Suzuki, Shinya; Kawasaki, Masahito

1995-11-01

The structure and magnetic properties of Sm{sub 3}(Fe{sub 0.85}Cr{sub 0.15}){sub 29}N{sub y} alloy were investigated. It was found that the alloy had the R{sub 3}(Fe,M){sub 29}-type structure and absorbed 4--5 wt.% of nitrogen which exceeds 4 nitrogen atoms per unit formula. The coercivity of the powder was greatly influenced by the nitrogen content and annealing. The Sm{sub 3}(Fe{sub 0.85}Cr{sub 0.15}){sub 29}N{sub y} alloy powder with 4.1 wt.% of nitrogen showed a high coercivity of 552 kA/m without fine grinding.

The effect of bronchoscope rotation on tracheal tube orientation at the glottic level in a mannequin.

PubMed

Wong, David T; Yau, Brian; Thapar, Shikha; Adhikary, Sanjib D

2010-10-01

This study examined the effect of external fibreoptic bronchoscope (FOB) rotations on endotracheal tube (ETT) orientations at the glottic level. Using a mannequin, a nasal FOB was inserted for image capture. A second FOB with a preloaded ETT taped to its top was inserted orally into mid-trachea. The FOB with the taped ETT was rotated as a unit in the axial plane to five different external angles (-90°, -45°, 0°, +45°, +90°). At each external rotation, the ETT was advanced into the trachea. The image of the ETT at the glottic level was captured. Endotracheal tube orientation was quantified according to the glottic zone faced by the ETT. The ETT orientations were compared amongst the five external FOB rotations using the Kruskal-Wallis Test, while the ETT orientations at -90°, -45°, +45°, and +90° FOB rotations were compared with 0° rotation using the Mann-Whitney U test. There was a significant difference in the ETT orientations amongst the five FOB rotations (P < 0.001). The ETT orientations at -90°, -45°, +45°, and +90° FOB rotations were different from the 0° rotation (P < 0.001 for all comparisons). A -90° FOB rotation was most effective in turning the ETT tip away from the right laryngeal structures and the interarytenoid tissue. With the ETT loaded on a FOB, rotation of the FOB prior to advancing the ETT is effective in changing the ETT orientation at the glottis. A -90° FOB rotation is most effective in turning the ETT tip away from the right laryngeal structures and interarytenoid tissue.

A fractional-N frequency divider for multi-standard wireless transceiver fabricated in 0.18 μm CMOS process

NASA Astrophysics Data System (ADS)

Wang, Jiafeng; Fan, Xiangning; Shi, Xiaoyang; Wang, Zhigong

2017-12-01

With the rapid evolution of wireless communication technology, integrating various communication modes in a mobile terminal has become the popular trend. Because of this, multi-standard wireless technology is one of the hot spots in current research. This paper presents a wideband fractional-N frequency divider of the multi-standard wireless transceiver for many applications. High-speed divider-by-2 with traditional source-coupled-logic is designed for very wide band usage. Phase switching technique and a chain of divider-by-2/3 are applied to the programmable frequency divider with 0.5 step. The phase noise of the whole frequency synthesizer will be decreased by the narrower step of programmable frequency divider. Δ-Σ modulator is achieved by an improved MASH 1-1-1 structure. This structure has excellent performance in many ways, such as noise, spur and input dynamic range. Fabricated in TSMC 0.18μm CMOS process, the fractional-N frequency divider occupies a chip area of 1130 × 510 μm2 and it can correctly divide within the frequency range of 0.8-9 GHz. With 1.8 V supply voltage, its division ratio ranges from 62.5 to 254 and the total current consumption is 29 mA.

Occult abnormal pregnancies after first post-embryo transfer serum beta-human chorionic gonadotropin levels of 1.0-5.0 mIU/mL.

PubMed

Maslow, Bat-Sheva L; Bartolucci, Alison; Sueldo, Carolina; Engmann, Lawrence; Benadiva, Claudio; Nulsen, John C

2016-04-01

To assess the occult pregnancy rate after "negative" first post-embryo transfer (ET) serum β-hCG results. Two-part retrospective cohort study and nested case series. University-based fertility center. A total of 1,571 negative first post-ET serum β-hCG results were included in the study; 1,326 results (primary cohort, June 2009-December 2013) were initially reported as <5 mIU/mL and 245 results (secondary cohort, January 2014-March 2015) were reported as discrete values from 1.0 to 5.0 mIU/mL. None. Rates of occult pregnancy, ectopic pregnancy, and complications after negative first post-ET serum β-hCG results. A total of 88.8% (1,178/1,326) of the negative first post-ET results reported as <5 were actually <1.0 mIU/mL. Occult pregnancy was incidentally identified in 1.2% (12/1,041) of subjects with follow-up. Six had ectopic pregnancies, and seven experienced serious complications; 11 (91.7%) of the 12 occult pregnancies had a first post-ET serum β-hCG level of 1.0-5.0 mIU/mL and 1 (8.3%) <1.0 mIU/mL. All pregnancies with serious complications had initial β-hCG levels of 1.0-5.0 mIU/mL. Of the 245 results reported as discreet values, occult pregnancies were diagnosed in 5.5% (9/163) of subjects with follow-up. One had an ectopic pregnancy, which was treated with methotrexate. There were no serious complications in the secondary cohort. The majority of negative first post-ET serum β-hCG levels are <1.0 mIU/mL. Results from 1.0 to 5.0 mIU/mL may fail to exclude abnormal pregnancy and are associated with poor outcomes compared with β-hCG levels <1.0 mIU/mL. Serial serum β-hCG may be warranted in this population. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

VizieR Online Data Catalog: Orion Integral Filament ALMA+IRAM30m N2H+(1-0) data (Hacar+, 2018)

NASA Astrophysics Data System (ADS)

Hacar, A.; Tafalla, M.; Forbrich, J.; Alves, J.; Meingast, S.; Grossschedl, J.; Teixeira, P. S.

2018-01-01

Combined ALMA+IRAM30m large-scale N2H+(1-0) emission in the Orion ISF. Two datasets are presented here in FITS format: 1.- Full data cube: spectral resolution = 0.1 kms-1 2.- Total integrated line intensity (moment 0) map Units are in Jy/beam See also: https://sites.google.com/site/orion4dproject/home (2 data files).

Digital Elevation Model, 0.25 m, Barrow Environmental Observatory, Alaska, 2013

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

Cathy Wilson; Garrett Altmann

This 0.25m horizontal resolution digital elevation model, DEM, was developed from Airborne Laser Altimetry flown by Aerometric Inc, now known as Quantum Spatial, Inc. on 12 July, 2013. One Mission was flown and the data jointly processed with LANL personnel to produce a 0.25m DEM covering a region approximately 2.8km wide and 12.4km long extending from the coast above North Salt Lagoon to south of Gas Well Road. This DEM encompasses a diverse range of hydrologic, geomorphic, geophysical and biological features typical of the Barrow Peninsula. Vertical accuracy at the 95% confidence interval was computed as 0.143m. The coordinate system,more » datum, and geoid for this DEM are UTM Zone 4N, NAD83 (2011), NAVD88 (GEOID09).« less

Valence, exchange interaction, and location of Mn ions in polycrystalline M nxG a1 -xN (x ≤0.04 )

NASA Astrophysics Data System (ADS)

Furrer, A.; Krämer, K. W.; Podlesnyak, A.; Pomjakushin, V.; Sheptyakov, D.; Safonova, O. V.

2018-04-01

We present an experimental study for polycrystalline samples of the diluted magnetic semiconductor M nxG a1 -xN (x ≤0.04 ) in order to address some of the existing controversial issues. X-ray and neutron diffraction, x-ray absorption near-edge structure, and electron paramagnetic resonance experiments were used to characterize the structural, electronic, and magnetic properties of the samples, and inelastic neutron scattering was employed to determine the magnetic excitations associated with Mn monomers and dimers. Our main conclusions are as follows: (i) The valence of the Mn ions is 2 + . (ii) The M n2 + ions experience a substantial single-ion axial anisotropy with parameter D =0.027 (3 )meV . (iii) Nearest-neighbor M n2 + ions are coupled antiferromagnetically. The exchange parameter J =-0.140 (7 )meV is independent of the Mn content x ; i.e., there is no evidence for hole-induced modifications of J towards a potentially high Curie temperature postulated in the literature.

Synthesis, crystal structure, and luminescence properties of a new nitride polymorph, β-Sr0.98Eu0.02AlSi4N7

NASA Astrophysics Data System (ADS)

Yoshimura, Fumitaka; Yamane, Hisanori; Nagasako, Makoto

2018-02-01

Prismatic vermilion single crystals 200 μm-2 mm in size, together with a white powder, were obtained by heating a mixture of binary nitrides containing Mg3N2 at 2030 °C under 0.85 MPa of N2. Yellow, thick-platelet single crystals with sizes of 150-500 μm were also found to grow at or near the surface of the product. Single crystal X-ray diffraction demonstrated that the vermilion crystals were orthorhombic Sr0.98Eu0.02AlSi4N7, which has been prepared in previous studies and is termed the α phase of this compound. The yellow crystals were revealed to be a new polymorph of Sr0.98Eu0.02AlSi4N7 (β phase) that crystalized in a monoclinic cell (a = 8.1062(1) Å, b = 9.0953(1) Å, c = 8.9802(2) Å, β = 111.6550(5)°, space group P21) with twins that could be examined by transmission and scanning transmission electron microscopy. β-Sr0.98Eu0.02AlSi4N7 was found to have a three-dimensional network structure formed by the stacking of two types of layers. One is a dreier layer of (Al/Si)N4 tetrahedra that consists of N vertex-sharing double chains of (Al/Si)N4 tetrahedra extending in the c-axis direction with Sr and Eu atoms aligned between the chains, while the other is a layer of (Al/Si)N4 tetrahedra connected by sharing N edges and vertexes. The crystal structure of β-Sr0.98Eu0.02AlSi4N7 is similar to those of certain oxynitrides, such as Sr3Al3+xSi13-xN21-xO2+x:Eu2+ (x ≈ 0) and Sr4.9Eu0.1Al5+xSi21-xN35-xO2+x (x ≈ 0). The peak wavelength and full width at half maximum in the emission spectrum obtained from single crystals of β-Sr0.98Eu0.02AlSi4N7 under excitation at 400 nm were 541 and 66 nm, respectively.

Magnetic properties of Sm2(Fe0.95M0.05)17Nx (M=Cr and Mn) anisotropic coarse powders with high coercivity

NASA Astrophysics Data System (ADS)

Ito, Mikio; Majima, Kazuhiko; Shimuta, Toru; Katsuyama, Shigeru; Nagai, Hiroshi

2002-09-01

Sm2(Fe0.95Cr0.05)17Nx and Sm2(Fe0.95Mn0.05)17Nx coarse powders 10-70 mum in size were synthesized by crushing mother alloy ingots into 32-74 mum in particle size and subsequent nitrogenation at 748 K in a flowing mixed gas of 60 vol % H2+40 vol % NH3. The effects of Cr or Mn substitution for Fe on the nitrogenation rate, magnetic properties, and microstructure of the Sm2Fe17Nx hard magnetic material were investigated. Cr and Mn substitution was quite effective for accelerating nitrogenation. When the powders were nitrogenated beyond x=3, amorphous phase formation was observed as the x value increased. The magnetic properties of the nitrogenated powders were significantly improved by Cr and Mn substitution, and these powders also possessed a satisfactory magnetic anisotropy. The maximum coercivity in this study, 0.59 MA/m, was obtained for the Sm2(Fe0.95Mn0.05)17N5.0 powder in spite of its large particle size. The high coercivity of the coarse powders was caused by a cell-like microstructure composed of fine 2-17 crystalline grains 20-30 nm in size surrounded by an amorphous phase.

26 CFR 1.401(m)-0 - Table of contents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 5 2013-04-01 2013-04-01 false Table of contents. 1.401(m)-0 Section 1.401(m)-0...) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-0 Table of contents... section in §§ 1.401(m)-1 through 1.401(m)-5. List of Sections § 1.401(m)-1Employee contributions and...

26 CFR 1.401(m)-0 - Table of contents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 5 2014-04-01 2014-04-01 false Table of contents. 1.401(m)-0 Section 1.401(m)-0...) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-0 Table of contents... section in §§ 1.401(m)-1 through 1.401(m)-5. List of Sections § 1.401(m)-1Employee contributions and...

26 CFR 1.401(m)-0 - Table of contents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 5 2012-04-01 2011-04-01 true Table of contents. 1.401(m)-0 Section 1.401(m)-0...) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-0 Table of contents... section in §§ 1.401(m)-1 through 1.401(m)-5. List of Sections § 1.401(m)-1Employee contributions and...

26 CFR 1.401(m)-0 - Table of contents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 5 2011-04-01 2011-04-01 false Table of contents. 1.401(m)-0 Section 1.401(m)-0...) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-0 Table of contents... section in §§ 1.401(m)-1 through 1.401(m)-5. List of Sections § 1.401(m)-1Employee contributions and...

Capture of 0.1-μm aerosol particles containing viable H1N1 influenza virus by N95 filtering facepiece respirators.

PubMed

Harnish, Delbert A; Heimbuch, Brian K; Balzli, Charles; Choe, Melanie; Lumley, April E; Shaffer, Ronald E; Wander, Joseph D

2016-01-01

Nosocomial infections pose an escalating threat to both patients and healthcare workers (HCWs). A widely recommended device for individual respiratory protection, the N95 filtering facepiece respirator (FFR) has been shown to provide efficient filtration of inert particles larger and smaller than the nominal most-penetrating particle size (MPPS) range, 0.03-0.3 μm. Humans generate respiratory aerosols in the MPPS range, suggesting that short-range disease transmission could occur via small infectious particles. Data presented here show that the N95 FFR will afford a significant measure of protection against infectious particles as small as a bare H1N1 influenza virion, and that the capture mechanism does not discriminate in favor of, or against, biological particles.

Contribution of Glottic Insufficiency to Perceived Breathiness in Classically Trained Singers.

PubMed

Graham, Ellen; Angadi, Vrushali; Sloggy, Joanna; Stemple, Joseph

2016-09-01

Breathiness in the singing voice is problematic for classical singers. Voice students and singing teachers typically attribute breathiness to breath management issues and breathing technique. The present study sought to determine whether glottic insufficiency may also contribute to breathiness in a singer's voice. Studies have revealed a relationship between insufficient vocal fold closure and inefficiency in the speaking voice. However, the effect of insufficient vocal fold closure on vocal efficiency in singers has yet to be determined. Two groups of voice students identified with and without breathiness issues underwent aerodynamic and acoustic voice assessment as well as laryngeal stroboscopy of the vocal folds to quantify the prevalence of insufficient vocal fold closure, also known as glottic insufficiency. These assessments revealed four groups: 1) those with glottic insufficiency and no perceived voice breathiness; 2) those with glottic sufficiency and perceived voice breathiness; 3) those with glottic insufficiency and perceived breathiness; and 4) those with glottic sufficiency and no perceived breathiness. Results suggest that previously undiscovered glottal insufficiency is common in young singers, particularly women, though the correlation with identified breathiness was not statistically significant. Acoustic and aerodynamic measures including noise-to-harmonics ratio, maximum phonation time, airflow rate, subglottal pressure, and laryngeal airway resistance were most sensitive to glottic insufficiency.

Surgical Treatment of Iatrogenic Ventral Glottic Stenosis Using a Mucosal Flap Technique

PubMed Central

Barnett, Timothy P.; O'Leary, John Mark; Dixon, Padraic M.

2016-01-01

Objective To describe a novel surgical technique for correcting postoperative ventral glottic stenosis (cicatrix or web formation) and the outcome in 2 Thoroughbred racehorses. Study Design Retrospective case report. Animals Thoroughbreds diagnosed with ventral glottic stenosis (n=2). Methods Horses presenting with iatrogenic ventral glottic stenosis and resultant exercise intolerance and abnormal exercise‐related noise were anesthetized and a midline sagittal skin incision was made over the ventral larynx and between the sternohyoideus muscles overlying the cricothyroid notch. The cricothyroid ligament, attached laryngeal cicatrix, and overlying mucosa were sagittally sectioned at the dorsal aspect of the cicatrix on the left side. The laryngeal mucosa, cicatrix, and underlying cricothyroid ligament immediately rostral and caudal to the cicatrix were sectioned in a medial (axial) direction as far as the right side of the cricothyroid notch. After resection of the majority of the attached cicatrix tissue, the residual mucosal flap (attached to the right side of the larynx) was reflected ventrally and sutured to the attachment of the cricothyroid ligament on the right side of the cricothyroid notch, creating an intact mucosal layer on the right side of the ventral larynx. Results Both horses had good intralaryngeal wound healing with minimal redevelopment of ventral glottic stenosis at 5 and 9 months postoperatively and were successfully returned to racing with complete absence of abnormal respiratory noise. Conclusion The unique laryngeal anatomy of horses, with a cartilage‐free ventral laryngeal area (cricothyroid notch), allowed the use of this novel surgical technique to successfully treat ventral glottic stenosis. PMID:27013024

Inverted Al0.25Ga0.75N/GaN ultraviolet p-i-n photodiodes formed on p-GaN template layer grown by metalorganic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Chang, Kuo-Hua; Sheu, Jinn-Kong; Lee, Ming-Lun; Tu, Shang-Ju; Yang, Chih-Ciao; Kuo, Huan-Shao; Yang, J. H.; Lai, Wei-Chih

2010-07-01

Inverted Al0.25Ga0.75N/GaN ultraviolet (UV) p-i-n photodiodes (PDs) were grown by selective-area regrowth on p-GaN template. The inverted devices with low-resistivity n-type AlGaN top-contact layers exhibited a typical zero-bias peak responsivity of 66.7 mA/W at 310 nm corresponding to the external quantum efficiency of 26.6%. The typical UV-to-visible (310/400 nm) spectral rejection ratio at zero-bias was over three orders of magnitude. The differential resistance and detectivity were obtained at approximately 6.2×1012 Ω and 3.4×1013 cm Hz1/2 W-1, respectively. Compared with conventional AlGaN/GaN-based UV p-i-n PDs, the proposed device structure can potentially achieve solar-blind AlGaN/GaN-based p-i-n PDs with low-aluminum content or aluminum-free p-contact layer and reduce excessive tensile strain due to the lattice mismatch between AlGaN and GaN layers.

Prognostic value of HPV-mRNA in sentinel lymph nodes of cervical cancer patients with pN0-status.

PubMed

Dürst, Matthias; Hoyer, Heike; Altgassen, Christoph; Greinke, Christiane; Häfner, Norman; Fishta, Alba; Gajda, Mieczyslaw; Mahnert, Ute; Hillemanns, Peter; Dimpfl, Thomas; Lenhard, Miriam; Petry, K Ulrich; Runnebaum, Ingo B; Schneider, Achim

2015-09-08

Up to 15% of patients with cervical cancer and pN0-status develop recurrent-disease. This may be due to occult metastatic spread of tumor cells. We evaluated the use of human-papillomavirus-(HPV)-mRNA as a molecular marker for disseminated tumor cells to predict the risk of recurrence. For this prospective, multi-center prognostic study, 189 patients free of lymphnode metastases by conventional histopathology could be analyzed. All patients underwent complete lymphadenectomy. Of each sentinel node (SLN) a biopsy was taken for the detection of HPV-E6-E7-mRNA. Median follow-up time after surgery was 8.1 years. HPV-mRNA could be detected in SLN of 52 patients (27.5%). Recurrence was observed in 22 patients. Recurrence-free-survival was significantly longer for patients with HPV-negative SLN (log rank p = 0.002). By Cox regression analysis the hazard ratio (95%CI) for disease-recurrence was 3.8 (1.5 - 9.3, p = 0.004) for HPV-mRNA-positive compared to HPV-mRNA-negative patients. After adjustment for tumor size as the most influential covariate the HR was still 2.8 (1.1 - 7.0, p = 0.030). In patients with cervical cancer and tumor-free lymph nodes by conventional histopathology HPV-mRNA-positive SLN were of prognostic value independent of tumor size. Particularly, patients with tumors larger than 20mm diameter could possibly benefit from further risk stratification using HPV-mRNA as a molecular marker.

Study of the Histopathologic Characteristics and Surface Morphologies of Glottic Carcinomas With Anterior Vocal Commissure Involvement.

PubMed

Wu, Jianhui; Zhao, Jing; Wang, Zhangfeng; Li, Zenghong; Luo, Jie; Liao, Bing; Yang, Zhiyun; Liu, Qihong; Wang, Bin; Wen, Weiping; Lei, Wenbin

2015-07-01

This article explores the features and the role of the anterior vocal commissure (AVC) structure and the surface morphologies of glottic carcinomas with AVC involvement to provide a reference for the selection of transoral carbon dioxide (CO2) laser surgery. A total of 31 cases of glottic carcinomas with AVC involvement from May 2012 to January 2014 were included. All patients underwent electronic laryngoscopic examinations and computed tomography scans to determine the surface morphology. After surgery, the tumor specimens were resected integrally, and axial serial sections parallel to the plane of vocal cords were taken to explore the features and possible invasion paths of the glottic carcinomas with AVC involvement. The rates of involvement of the supraglottis and subglottis were 71.4% and 14.8%, respectively, via the AVC. The involvement of the superficial layer of the unilateral or bilateral vocal cords without involvement of the vocal muscle in the AVC region (IVM) or the cartilage was present in 15 cases (48.4%). The involvement of the superficial layer of the unilateral and bilateral vocal cords occurred in 16 cases (51.6%) with the IVM in 13 cases and the involvement of the intermediate lamina of the thyroid cartilage (ITC) in 8 cases. The involvement of the ITC was associated with the involvement of the vocal muscle of the AVC region (P < 0.05). Among the pushing carcinomas, 15 of 21 (71.4%) presented with well-defined tumor mass, and 8 of 10 (80.0%) infiltrating carcinomas presented with multiple tumor nests that were often surrounded by fibrosis (P < 0.05). The AVC is an important path of invasion of subglottic in glottic carcinomas but less so for suparglottic. The Broyles' ligaments acted as a barrier against the spread of the tumors to the thyroid cartilage, but this role was obviously weaken by the involvement of the vocal muscle of the AVC region. The infiltrating carcinomas presented with multiple tumor nests in fibrous tissue. When CO2 laser

Strain modulation-enhanced Mg acceptor activation efficiency of Al0.14Ga0.86N/GaN superlattices with AlN interlayer

NASA Astrophysics Data System (ADS)

Wang, Lei; Li, Rui; Li, Ding; Liu, Ningyang; Liu, Lei; Chen, Weihua; Wang, Cunda; Yang, Zhijian; Hu, Xiaodong

2010-02-01

AlN layer was grown as interlayer between undoped GaN and Mg doped Al0.14Ga0.86N/GaN superlattices (SLs) epilayer to modulate the strain distribution between Al0.14Ga0.86N barrier and GaN well layers in SLs sample. Strain relaxation was observed in the SLs sample with AlN interlayer by x-ray diffraction reciprocal space mapping method. The measured hole concentration of SLs sample with AlN interlayer at room temperature was over 1.6×1018 cm-3 but that was only 6.6×1016 cm-3 obtained in SLs sample without AlN interlayer. Variable temperature Hall-effect measurement showed that the acceptor activation energy decreased from 150 to 70 meV after inserting the AlN layer, which indicated that the strain modulation of SLs induced by AlN interlayer was beneficial to the Mg acceptor activation and hole concentration enhancement.

Ultrafast carrier dynamics in a GaN/Al 0.18Ga0.82N superlattice

NASA Astrophysics Data System (ADS)

Mahler, Felix; Tomm, Jens W.; Reimann, Klaus; Woerner, Michael; Elsaesser, Thomas; Flytzanis, Christos; Hoffmann, Veit; Weyers, Markus

2018-04-01

Relaxation processes of photoexcited carriers in a GaN /Al0.18Ga0.82N superlattice are studied in femtosecond spectrally resolved reflectivity measurements at ambient temperature. The transient reflectivity reveals electron trapping into defect states close to the conduction-band minimum with a 150-200 fs time constant, followed by few-picosecond carrier cooling. A second slower trapping process into a different manifold of defect states is observed on a time scale of approximately 10 ps. Our results establish the prominent role of structural defects and disorder for ultrafast carrier dynamics in nitride semiconductor structures.

Effect of temperature on the electrical properties of Zn0.95M0.05O (M = Zn, Fe, Ni)

NASA Astrophysics Data System (ADS)

Sedky, A.; Mohamed, S. B.

2014-01-01

We report here the structural and electrical properties of Zn0.95M0.05O ceramic varistors, M = Zn, Ni and Fe. The samples were tested for phase purity and structural morphology by using X-Ray diffraction XRD and scanning electron microscope SEM techniques. The current-voltage characteristics J-E were obtained by dc electrical measurements in the temperature range of 300-500 K. Addition of doping did not influence the hexagonal wurtzite structure of ZnO ceramics. Furthermore, the lattice parameters ratio c/a for hexagonal distortion and the length of the bond parallel to the c axis, u were nearly unaffected. The average grain size was decreased from 1.57 μm for ZnO to 1.19 μm for Ni sample and to 1.22 μm for Fe sample. The breakdown field EB was decreased as the temperature increased, in the following order: Fe > Zn > Ni. The nonlinear region was clearly observed for all samples as the temperature increased up to 400 K and completely disappeared with further increase of temperature up to 500 K. The values of nonlinear coefficient, a were between 1.16 and 42 for all samples, in the following order: Fe > Zn > Ni. Moreover, the electrical conductivity s was gradually increased as the temperature increased up to 500 K, in the following order: Ni > Zn > Fe. On the other hand, the activation energies were 0.194 eV, 0.136 and 0.223 eV for all samples, in the following order: Fe, Zn and Ni. These results have been discussed in terms of valence states, magnetic moment and thermo-ionic emission, which were produced by the doping, and controlling the potential barrier of ZnO.

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.

Electrolytic conductivity at 0.5 S m-1 and 5 mS m-1

NASA Astrophysics Data System (ADS)

Seitz, S.; Sander, B.; Snedden, A.; DeLeeBeeck, L.; Canaza, G. T.; Asakai, T.; Maksimov, I.; Song, X.; Wang, H.; Kozlowski, W.; Dumanska, J.; Jakusovszky, B.; Szilágyi, Z. N.; Gavrilkin, V.; Stennik, O.; Ovchinnikov, Y.; Gonzaga, F. B.; da Cruz Cunha, K.; Ferraz, S. F.; Hanková, Z.; Máriássy, M.; Vicarova, M.; Vospelova, A.; Ortiz-Aparicio, J. L.; Lara-Manzano, J. V.; Uribe-Godínez, J.; Stoica, D.; Fisicaro, P.; Suvorov, V. I.; Konopelko, L. A.; Smirnov, A. M.; Amaya, R. C.; Quezada, H. T.

2017-01-01

Key Comparison CCQM-K36.2016 was a follow-up comparison for K36 and provided updated support for the corresponding calibration and measurement capability (CMC) entries in the BIPM CMC database. It aimed to demonstrate the capabilities of the participating NMIs to measure electrolytic conductivity of aqueous electrolyte solutions in the conductivity range 0.15 S m-1 to 1.5 S m-1 and in the conductivity range 1.5 mS m-1 to 15 mS m-1. To this end electrolytic conductivity of a potassium chloride solution (nominal conductivity 0.5 S m-1) and of a HCl solution (nominal conductivity 5 mS m-1) had to be measured. 17 NMIs participated in the comparison. The key comparison reference value (KCRV) of the KCl solution was (0.50999 +/-0.00032) S m-1 and the KCRV of the HCl solution was (4.9877 +/-0.012) mS m-1. Both values were estimated from the medians of the results considered eligible for KCRV calculation. They were given with their expanded uncertainties (95% coverage). The majority of the 0.5 S m-1 results were consistent with the KCRV. Two institutes showed a small inconsistency, one outlier was observed. The conductivity of the HCl solution showed a small, but steady linear drift of 0.00006843 mS m-1 per day during the measurement period and was corrected for KCRV calculation. Some institutes reported unstable measurement conditions for this solution. The results of seven participants have been inconsistent with the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Essentials of MDS 3.0 section M: skin conditions.

PubMed

Levine, Jeffrey M; Roberson, Sharon; Ayello, Elizabeth A

2010-06-01

To provide information about the impending changes in the Minimum Data Set (MDS) Section M on skin conditions and its implications for practice. This continuing education activity is intended for physicians and nurses with an interest in skin and wound care. After participating in this educational activity, the participant should be better able to: 1. Compare section M of MDS version 2.0 to MDS version 3.0. 2. Apply the complexities of the MDS 3.0 section M for coding. 3. Demonstrate accurate and complete documentation of wounds as per MDS 3.0 section M.

Regional hyperthermia in conjunction with definitive radiotherapy against recurrent or locally advanced prostate cancer T3 pN0 M0.

PubMed

Tilly, Wolfgang; Gellermann, Johanna; Graf, Reinhold; Hildebrandt, Bert; Weissbach, Lothar; Budach, Volker; Felix, Roland; Wust, Peter

2005-01-01

Since long-term results of the standard treatment of locally advanced or recurrent prostatic carcinoma are unsatisfactory, the role for additional regional hyperthermia was evaluated in a phase I/II study. From 08/1996 to 03/2000, 22 patients were treated by a standard irradiation regimen (68.4 Gy) in combination with regional hyperthermia (weekly, five to six times), and five of 22 patients received short-term (neoadjuvant) hormonal treatment. Of these, 15 patients had primary prostatic carcinoma T3 pN0 M0 and seven a histologically confirmed local recurrence after radical prostatectomy. Feasibility of hyperthermia, and acute/late toxicity as well as long-term follow-up (prostate- specific antigen [PSA] control, overall survival) were analyzed. Clinical endpoints were correlated with thermal parameters. Mean maximum temperatures along the urethra of 41.4 degrees C (41.0 degrees C for the recurrences), and mean T(90) values of 40.7 degrees C could be achieved. Severe acute toxicity of grade 3 occurred at the rectum in three, at the urethra in four, at the intestine in one, and a burn induced by hyperthermia in one of 22 patients. Late toxicity was only observed rectally in one patient (grade 3) and at the urethra in two patients (grade 2). There was no correlation between thermal parameters and any toxicity. The survival curves showed a PSA control for primary prostatic carcinoma > 50% after 6 years, but no long-term PSA control for the recurrences. Overall survival after 6 years was 95% for primary carcinoma, and 60% for the recurrences. There was a clear correlation between higher temperatures or thermal doses with long-term PSA control. Regional hyperthermia might be a low-toxicity approach to increase PSA control of common treatment schedules. Further evaluation, in particular employing improved hyperthermia technology, is worthwhile.

Prognostic stratification of patients with T3N1M0 non-small cell lung cancer: which phase should it be?

PubMed

Kilicgun, Ali; Tanriverdi, Ozgur; Turna, Akif; Metin, Muzaffer; Sayar, Adnan; Solak, Okan; Urer, Nur; Gurses, Atilla

2012-06-01

In the 1997 revision of the TNM staging system for lung cancer, patients with T3N0M0 disease were moved from stage IIIA to stage IIB since these patients have a better prognosis. Despite this modification, the local lymph node metastasis remained the most important prognostic factor in patients with lung cancer. The present study aimed to evaluate the prognosis of patients with T3N1 disease as compared with that of patients with stages IIIA and IIB disease. During 7-year period, 313 patients with non-small cell lung cancer (297 men, 16 women) who had resection were enrolled. The patients were staged according the 2007 revision of Lung Cancer Staging by American Joint Committee on Cancer. The Kaplan-Meier statistics was used for survival analysis, and comparisons were made using Cox proportional hazard method. The 5-year survival of patients with stage IIIA disease excluding T3N1 patients was 40%, whereas the survival of the patients with stage IIB disease was 66% at 5 years. The 5-year survival rates of stage III T3N1 patients (single-station N1) was found to be higher than those of patients with stage IIIA disease (excluding pT3N1 patients, P = 0.04), while those were found to be similar with those of patients with stage IIB disease (P = 0.4). Survival of the present cohort of patients with T3N1M0 disease represented the survival of IIB disease rather than IIIA non-small cell lung cancer. Further studies are needed to suggest further revisions in the recent staging system regarding T3N1MO disease.

Coupled channel analysis of overlinepp annihilation into π0π0π0, π0ηη and π0π0η

NASA Astrophysics Data System (ADS)

Amsler, C.; Armstrong, D. S.; Baker, C. A.; Barnett, B. M.; Batty, C. J.; Benayoun, M.; Beuchert, K.; Birien, P.; Blüm, P.; Bossingham, R.; Braune, K.; Brose, J.; Bugg, D. V.; Case, T.; Chung, S. U.; Cooper, A. R.; Cramer, O.; Crowe, K. M.; Degener, T.; Dietz, H. P.; Djaoshvili, N.; Dombroski, S. v.; Doser, M.; Dünnweber, W.; Engelhardt, D.; Englert, M.; Faessler, M. A.; Felix, C.; Giarritta, P.; Hackmann, R.; Haddock, R. P.; Heinsius, F. H.; Herz, M.; Hessey, N. P.; Hidas, P.; Holzhaussen, C.; Illinger, P.; Jamnik, D.; Kalinowsky, H.; Kalteyer, B.; Kämmle, B.; Kiel, T.; Kisiel, J.; Klempt, E.; Koch, H.; Kobel, M.; Kolo, C.; Kunze, M.; Lakata, M.; Landua, R.; Lüdemann, J.; Matthäy, H.; McCrady, R.; Merlo, J. P.; Meyer, C. A.; Montanet, L.; Noble, A.; Ouared, R.; Ould-Saada, F.; Peters, K.; Pinder, C. N.; Pinter, G.; Ravndal, S.; Regenfus, C.; Schäfer, E.; Schmidt, P.; Schütrumpf, M.; Seibert, R.; Spanier, S.; Stöck, H.; Straßburger, C.; Strohbusch, U.; Suffert, M.; Thoma, U.; Tischhäuser, M.; Urner, D.; Völcker, C.; Walter, F.; Walther, D.; Wiedner, U.; Winter, N.; Zoll, J.; Zou, B. S.; Zupančič, Č.; Crystal Barrel Collaboration

1995-02-01

We confirm the existence of the two IG( JPC) = 0 +(0 ++) resonances f0(1370) and f0(1500) reported by us in earlier analyses. The analysis presented here couples the final states π0π0π0, π0π0η and π0ηη of overlinepp annihilation at rest. It is based on a 3 × 3 K-matrix. We find masses and widths of M = (1390±30) MeV, Γ = (380±80) MeV; and M = (1500±10) MeV, Γ = (154 ± 30) MeV, respectively. The product branching ratios for the production and decay into π0π0 and ηη of the f 0(1500) are (1.27 ± 0.33) · 10 -3 and (0.60 ± 0.17) · 10 -3, respectively.

Search for the Θ+ pentaquark in the reactions γp→K¯0K+n and γp→K¯0K0p

NASA Astrophysics Data System (ADS)

de Vita, R.; Battaglieri, M.; Kubarovsky, V.; Baltzell, N. A.; Bellis, M.; Goett, J.; Guo, L.; Mutchler, G. S.; Stoler, P.; Ungaro, M.; Weygand, D. P.; Amaryan, M. J.; Ambrozewicz, P.; Anghinolfi, M.; Asryan, G.; Avakian, H.; Bagdasaryan, H.; Baillie, N.; Ball, J. P.; Batourine, V.; Bedlinskiy, I.; Benmouna, N.; Berman, B. L.; Biselli, A. S.; Boiarinov, S.; Bouchigny, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Careccia, S. L.; Carman, D. S.; Chen, S.; Clinton, E.; Cole, P. L.; Collins, P.; Coltharp, P.; Crabb, D.; Crannell, H.; Crede, V.; Cummings, J. P.; Dale, D.; de Masi, R.; de Sanctis, E.; Degtyarenko, P. V.; Deur, A.; Dharmawardane, K. V.; Djalali, C.; Dodge, G. E.; Donnelly, J.; Doughty, D.; Dugger, M.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Funsten, H.; Gabrielyan, M. Y.; Gan, L.; Garçon, M.; Gasparian, A.; Gavalian, G.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glamazdin, O.; Goetz, J. T.; Golovach, E.; Gonenc, A.; Gordon, C. I. O.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Gyurjyan, V.; Hadjidakis, C.; Hafidi, K.; Hakobyan, H.; Hakobyan, R. S.; Hardie, J.; Hersman, F. W.; Hicks, K.; Hleiqawi, I.; Holtrop, M.; Hyde-Wright, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Ito, M. M.; Jenkins, D.; Jo, H. S.; Joo, K.; Juengst, H. G.; Kellie, J. D.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Kossov, M.; Kramer, L. H.; Kuhn, J.; Kuhn, S. E.; Kuleshov, S. V.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Lee, T.; Li, Ji; Livingston, K.; Lu, H. Y.; MacCormick, M.; Markov, N.; McKinnon, B.; Mecking, B. A.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mibe, T.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mochalov, V.; Mokeev, V.; Morand, L.; Morrow, S. A.; Moteabbed, M.; Nadel-Turonski, P.; Nakagawa, I.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niroula, M. R.; Niyazov, R. A.; Nozar, M.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Paterson, C.; Pierce, J.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rosner, G.; Rossi, P.; Sabatié, F.; Salgado, C.; Santoro, J. P.; Sapunenko, V.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Shvedunov, N. V.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Stavinsky, A.; Stepanyan, S. S.; Stepanyan, S.; Stokes, B. E.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tedeschi, D. J.; Teymurazyan, A.; Thoma, U.; Tkabladze, A.; Tkachenko, S.; Todor, L.; Tur, C.; Vineyard, M. F.; Vlassov, A. V.; Watts, D. P.; Weinstein, L. B.; Williams, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Zana, L.; Zhang, J.; Zhao, B.; Zhao, Z.

2006-08-01

The exclusive reactions γp→K¯0K+n and γp→K¯0K0p have been studied in the photon energy range 1.6 3.8 GeV, searching for evidence of the exotic baryon Θ+(1540) in the decays Θ+→nK+ and Θ+→pK0. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70pb-1. The reactions have been isolated by detecting the K+ and proton directly, the neutral kaon via its decay to KS→π+π- and the neutron or neutral kaon via the missing mass technique. The mass and width of known hyperons such as Σ+, Σ- and Λ(1116) were used as a check of the mass determination accuracy and experimental resolution. Approximately 100 000 Λ*(1520)’s and 150 000 ϕ’s were observed in the K¯0K+n and K¯0K0p final state, respectively. No evidence for the Θ+ pentaquark was found in the nK+ or pKS invariant mass spectra. Upper limits were set on the production cross section of the reaction γp→K¯0Θ+ as functions of center-of-mass angle, nK+ and pKS masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the Θ+ width, ΓΘ+, ranging between 0.01 and 7 MeV.

Risk of fatal cerebrovascular accidents after external beam radiation therapy for early-stage glottic laryngeal cancer.

PubMed

Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O'Malley, Bert; Weinstein, Gregory S; Bekelman, Justin E

2014-05-01

This study compared the risk of fatal cerebrovascular accidents (CVAs) in patients with early-stage glottic laryngeal cancer receiving surgery or external beam radiation therapy (EBRT). Using a competing risks survival analysis, we compared the risk of death because of CVA among patients with early-stage glottic laryngeal cancer receiving surgery or EBRT in the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8%; 95% confidence interval [CI], 2.3% to 3.4%) compared to surgery (1.5%; 95% CI, 0.8% to 2.3%; p = .024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted hazard ratio [HR], 1.75; 95% CI, 1.04-2.96; p = .037). Treatment for early-stage glottic laryngeal cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. Copyright © 2013 Wiley Periodicals, Inc.

FInvestigation of enhancement mode HfO2 insulated N-polarity GaN/InN/GaN/In0.9Al0.1N heterostructure MISHEMT for high-frequency applications

NASA Astrophysics Data System (ADS)

Mohanbabu, A.; Mohankumar, N.; Godwin Raj, D.; Sarkar, Partha

2017-08-01

In this paper, we examined normally-OFF N-polar InN-channel Metal insulated semiconductor high-electron mobility transistors (MISHEMTs) device with a relaxed In0.9Al0.1N buffer layer. In addition, the enhancement-mode operation of the N-polar structure was investigated. The effect of scaling in N-polar MISHEMT, such as the dielectric and the channel thickness, alter the electrical behavior of the device. We have achieved a maximum drain current of 1.17 A/mm, threshold voltage (VT) =0.728 V, transconductance (gm) of 2.9 S mm-1, high ION/IOFF current ratio of 3.23×103, lowest ON-state resistance (RON) of 0.41 Ω mm and an intrinsic delay time (τ) of 1.456 Fs along with high-frequency performance with ft/ fmaxof 90 GHz/109 GHz and 180 GHz/260 GHz for TCH =0.5 nm at Vds =0.5 V and 1.0 V. The numerically simulated results of highly confined GaN/InN/GaN/In0.9Al0.1N heterostructure MISHEMT exhibits outstanding potential as one of the possibility to replace presently used N-polar MISHEMTs for delivering high power density and frequency at RF/power amplifier applications.

Extended hot carrier lifetimes observed in bulk In{sub 0.265±0.02}Ga{sub 0.735}N under high-density photoexcitation

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

Zhang, Yi; Tayebjee, Murad J. Y.; Smyth, Suntrana

2016-03-28

We have investigated the ultrafast carrier dynamics in a 1 μm bulk In{sub 0.265}Ga{sub 0.735}N thin film grown using energetic neutral atom-beam lithography/epitaxy molecular beam epitaxy. Cathodoluminescence and X-ray diffraction experiments are used to observe the existence of indium-rich domains in the sample. These domains give rise to a second carrier population and bi-exponential carrier cooling is observed with characteristic lifetimes of 1.6 and 14 ps at a carrier density of 1.3 × 10{sup 16 }cm{sup −3}. A combination of band-filling, screening, and hot-phonon effects gives rise to a two-fold enhanced mono-exponential cooling rate of 28 ps at a carrier density of 8.4 × 10{sup 18 }cm{sup −3}. Thismore » is the longest carrier thermalization time observed in bulk InGaN alloys to date.« less

The structure of 0- to 0.2-m.y.-old oceanic crust at 9°N on the East Pacific Rise from expanded spread profiles

NASA Astrophysics Data System (ADS)

Vera, E. E.; Mutter, J. C.; Buhl, P.; Orcutt, J. A.; Harding, A. J.; Kappus, M. E.; Detrick, R. S.; Brocher, T. M.

1990-09-01

We analyze four expanded spread profiles acquired at distances of 0, 2.1, 3.1, and 10 km (0-0.2 m.y.) from the axis of the East Pacific Rise between 9° and 10°N. Velocity-depth models for these profiles have been obtained by travel time inversion in the τ-p domain, and by x-t forward modeling using the WKBJ and the reflectivity methods. We observe refracted arrivals that allow us to determine directly the uppermost crustal velocity structure (layer 2A). At the seafloor we find very low Vp and VS/Vp values around 2.2 km/s and ≤ 0.43. In the topmost 100-200 m of the crust, Vp remains low (≤ 2.5 km/s) then rapidly increases to 5 km/s at ˜500 m below the seafloor. High attenuation values (Qp < 100) are suggested in the topmost ˜500 m of the crust. The layer 2-3 transition probably occurs within the dike unit, a few hundred meters above the dike-gabbro transition. This transition may mark the maximum depth of penetration by a cracking front and associated hydrothermal circulation in the axial region above the axial magma chamber (AMC). The on-axis profile shows arrivals that correspond to the bright AMC event seen in reflection lines within 2 km of the rise axis. The top of the AMC lies 1.6 km below the seafloor and consists of molten material where Vp ≈ 3 km/s and VS = 0. Immediately above the AMC, there is a zone of large negative velocity gradients where, on the average, Vp decreases from ˜6.3 to 3 km/s over a depth of approximately 250 m. Associated with the AMC there is a low velocity zone (LVZ) that extends to a distance no greater than 10 km away from the rise axis. At the top of the LVZ, sharp velocity contrasts are confined to within 2 km of the rise axis and are associated with molten material or material with a high percentage of melt which would be concentrated only in a thin zone at the apex of the LVZ, in the axial region where the AMC event is seen in reflection lines. Away from the axis, the transition to the LVZ is smoother, the top of the

Near-infrared (0.8-4.0 m) spectroscopy of mimas, enceladus, tethys, and rhea

USGS Publications Warehouse

Emery, J.P.; Burr, D.M.; Cruikshank, D.P.; Brown, R.H.; Dalton, J.B.

2005-01-01

Spectral measurements from the ground in the time leading up to the Cassini mission at Saturn provide important context for the interpretation of the forthcoming spacecraft data. Whereas ground-based observations cannot begin to approach the spatial scales Cassini will achieve, they do possess the benefits of better spectral resolution, a broader possible time baseline, and unique veiewing geometries not obtained by spacecraft (i.e., opposition). In this spirit, we present recent NIR reflectance spectra of four icy satellites of Saturn measured with the SpeX instrument at the IRTF. These measurements cover the range 0.8-4.0 m of both the leading and trailing sides of Tethys and the leading side of Rhea. The L-band region (2.8-4.0 m) offers new opportunities for searches of minor components on these objects. Additionally, these data include 0.8-2.5 m spectra of both the leading and trailing sides of Mimas and of the (mostly) trailing side of Enceladus. The spectrum of Enceladus shows activity near 2.25 m that we interpret as a possible signature of NH3 ice. The presence of ammonia in the Saturn system is not unexpected, and may help explain the apparent recent geologic activity of Enceladus. Analysis of leading/trailing differences inH2O band depths, spectral slopes, and albedo imply a separate regime of surface modification for Mimas and Enceladus than for the more distant icy satellites (Tethys, Dione, Rhea). Aside from the potential NH3 on Enceladus, no other minor constituents are detected in these icy surfaces.

A 12b 200kS/s 0.52mA 0.47mm2 Algorithmic A/D Converter for MEMS Applications

NASA Astrophysics Data System (ADS)

Kim, Young-Ju; Choi, Hee-Cheol; Lee, Seung-Hoon; Cho, Dongil “Dan”

This work describes a 12b 200kS/s 0.52mA 0.47mm2 ADC for sensor applications such as motor control, 3-phase power control, and CMOS image sensors simultaneously requiring ultra-low power and small size. The proposed ADC is based on the conventional algorithmic architecture with a recycling signal path to optimize sampling rate, resolution, chip area, and power consumption. The input SHA with eight input channels employs a folded-cascode amplifier to achieve a required DC gain and a high phase margin. A 3-D fully symmetric layout with critical signal lines shielded reduces the capacitor and device mismatch of the multiplying D/A converter while switched-bias power-reduction circuits minimize the power consumption of analog amplifiers. Current and voltage references are integrated on chip with optional off-chip voltage references for low glitch noise. The down-sampling clock signal selects the sampling rate of 200kS/s and 10kS/s with a further reduced power depending on applications. The prototype ADC in a 0.18μm n-well 1P6M CMOS process demonstrates a maximum measured DNL and INL within 0.40 LSB and 1.97 LSB and shows a maximum SNDR and SFDR of 55dB and 70dB at all sampling frequencies up to 200kS/s, respectively. The ADC occupies an active die area of 0.47mm2 and consumes 0.94mW at 200kS/s and 0.63mW at 10kS/s with a 1.8V supply.

Interface properties of an O2 annealed Au/Ni/n-Al0.18Ga0.82N Schottky contact

NASA Astrophysics Data System (ADS)

Legodi, M. J.; Meyer, W. E.; Auret, F. D.

2012-05-01

We oxidized a Ni/Au metal bi-layer contact fabricated on HVPE Al0.18Ga0.82N from 373 K to 573 K in 100 K steps. In the range 1 kHz to 2 MHz, the Capacitance-Voltage-Frequency (C-V-f) measurements reveal a frequency dispersion of the capacitance and the presence of an anomalous peak at 0.4 V owing to the presence of interface states in the as deposited contact system. The dispersion was progressively removed by O2 anneals from temperatures as low as 373 K. These changes are accompanied by an improvement in the overall quality of the Schottky system: the ideality factor, n, improves from 2.09 to 1.26; the Schottky barrier height (SBH), determined by the Norde [1] method, increases from 0.72 eV to 1.54 eV. From the Nicollian and Goetzberger model [2], we calculated the energy distribution of the density of interface states, NSS. Around 1 eV above the Al0.18Ga0.82N valence band, NSS, decreases from 2.3×1012 eV-1 cm-2 for the un-annealed diodes to 1.3×1012 eV-1 cm-2 after the 573 K anneal. Our results suggest the formation of an insulating NiO leading to a MIS structure for the oxidized Au/Ni/Al0.18Ga0.82N contact.

The spectrum of Pluto, 0.40-0.93 μm. I. Secular and longitudinal distribution of ices and complex organics

NASA Astrophysics Data System (ADS)

Lorenzi, V.; Pinilla-Alonso, N.; Licandro, J.; Cruikshank, D. P.; Grundy, W. M.; Binzel, R. P.; Emery, J. P.

2016-01-01

Context. During the past 30 years the surface of Pluto has been characterized and its variability monitored through continuous near-infrared spectroscopic observations. But in the visible range only a few data are available. Aims: The aim of this work is to define Pluto's relative reflectance in the visible range to characterize the different components of its surface, and to provide ground based observations in support of the New Horizons mission. Methods: We observed Pluto on six nights between May and July 2014 with the imager/spectrograph ACAM at the William Herschel Telescope (La Palma, Spain). The six spectra obtained cover a whole rotation of Pluto (Prot = 6.4 days). For all the spectra, we computed the spectral slope and the depth of the absorption bands of methane ice between 0.62 and 0.90 μm. To search for shifts in the center of the methane bands, which are associated with dilution of CH4 in N2, we compared the bands with reflectances of pure methane ice. Results: All the new spectra show the methane ice absorption bands between 0.62 and 0.90 μm. Computation of the depth of the band at 0.62 μm in the new spectra of Pluto and in the spectra of Makemake and Eris from the literature, allowed us to estimate the Lambert coefficient at this wavelength at temperatures of 30 K and 40 K, which has never been measured before. All the detected bands are blueshifted with respect to the position for pure methane ice, with minimum shifts correlated to the regions where the abundance of methane is higher. This could be indicative of a dilution of CH4:N2 that is more saturated in CH4. The longitudinal and secular variations in the parameters measured in the spectra are in accordance with results previously reported in the literature and with the distribution of the dark and bright materials that show the Pluto's color maps from New Horizons.

Photoelectron spectroscopic study of the hydrated nucleoside anions: Uridine(-)(H(2)O)(n=0-2), cytidine(-)(H(2)O)(n=0-2), and thymidine(-)(H(2)O)(n=0,1).

PubMed

Li, Xiang; Wang, Haopeng; Bowen, Kit H

2010-10-14

The hydrated nucleoside anions, uridine(-)(H(2)O)(n=0-2), cytidine(-)(H(2)O)(n=0-2), and thymidine(-)(H(2)O)(n=0,1), have been prepared in beams and studied by anion photoelectron spectroscopy in order to investigate the effects of a microhydrated environment on parent nucleoside anions. Vertical detachment energies (VDEs) were measured for all eight anions, and from these, estimates were made for five sequential anion hydration energies. Excellent agreement was found between our measured VDE value for thymidine(-)(H(2)O)(1) and its calculated value in the companion article by S. Kim and H. F. Schaefer III.

Photoelectron spectroscopic study of the hydrated nucleoside anions: Uridine-(H2O)n=0-2, cytidine-(H2O)n=0-2, and thymidine-(H2O)n=0,1

NASA Astrophysics Data System (ADS)

Li, Xiang; Wang, Haopeng; Bowen, Kit H.

2010-10-01

The hydrated nucleoside anions, uridine-(H2O)n=0-2, cytidine-(H2O)n=0-2, and thymidine-(H2O)n=0,1, have been prepared in beams and studied by anion photoelectron spectroscopy in order to investigate the effects of a microhydrated environment on parent nucleoside anions. Vertical detachment energies (VDEs) were measured for all eight anions, and from these, estimates were made for five sequential anion hydration energies. Excellent agreement was found between our measured VDE value for thymidine-(H2O)1 and its calculated value in the companion article by S. Kim and H. F. Schaefer III.

Prospective Trial of Stereotactic Body Radiation Therapy for Both Operable and Inoperable T1N0M0 Non-Small Cell Lung Cancer: Japan Clinical Oncology Group Study JCOG0403

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

Nagata, Yasushi, E-mail: nagat@hiroshima-u.ac.jp; Hiraoka, Masahiro; Shibata, Taro

2015-12-01

Purpose: To evaluate, in Japan Clinical Oncology Group study 0403, the safety and efficacy of stereotactic body radiation therapy (SBRT) in patients with T1N0M0 non-small cell lung cancer (NSCLC). Methods and Materials: Eligibility criteria included histologically or cytologically proven NSCLC, clinical T1N0M0. Prescribed dose was 48 Gy at the isocenter in 4 fractions. The primary endpoint was the percent (%) 3-year overall survival. The threshold % 3-year survival to be rejected was set at 35% for inoperable patients, whereas the expected % 3-year survival was 80% for operable patients. Results: Between July 2004 and November 2008, 169 patients from 15 institutionsmore » were registered. One hundred inoperable and 64 operable patients (total 164) were eligible. Patients' characteristics were 122 male, 47 female; median age 78 years (range, 50-91 years); adenocarcinomas, 90; squamous cell carcinomas, 61; others, 18. Of the 100 inoperable patients, the % 3-year OS was 59.9% (95% confidence interval 49.6%-68.8%). Grade 3 and 4 toxicities were observed in 10 and 2 patients, respectively. No grade 5 toxicity was observed. Of the 64 operable patients, the % 3-year OS was 76.5% (95% confidence interval 64.0%-85.1%). Grade 3 toxicities were observed in 5 patients. No grade 4 and 5 toxicities were observed. Conclusions: Stereotactic body radiation therapy for stage I NSCLC is effective, with low incidences of severe toxicity. This treatment can be considered a standard treatment for inoperable stage I NSCLC. This treatment is promising as an alternative to surgery for operable stage I NSCLC.« less

First Experiments with e-<m:mfenced close="" open="/"><m:mphantom>:mpadded width="0pt">e-H-m:mpadded>:mfenced> H- Plasmas: Enhanced Mode Damping and Transport

NASA Astrophysics Data System (ADS)

Kabantsev, A. A.; Thompson, K. A.; Driscoll, C. F.

2017-10-01

Negative Hydrogen ions are produced and confined in a room-temperature electron plasma, causing enhanced mode damping and particle transport effects. We accumulate an H- charge fraction nH-:mfenced close="" open="/"><m:mphantom>:mpadded width="0pt">nH-ne 20 % m:mpadded>:mfenced> ne 20 % in about 200 seconds, as externally excited H2 molecules undergo dissociative electron attachment in the plasma. The accumulated H- fraction causes a novel algebraic damping of diocotron mode amplitude A(t) , and the damping is coincident with an enhanced outward drift υr of the H- ions. That is, dA <m:mfenced close="" open="/"><m:mphantom>:mpadded width="0pt"> dA dt = - α m:mpadded>:mfenced> dt = - α , with α nH- *υr . We observe that heating the e-<m:mfenced close="" open="/"><m:mphantom>:mpadded width="0pt">e-H-m:mpadded>:mfenced> H- plasma terminates the enhanced damping and enhanced centrifugal separation, both of which resume when plasma re-cools by cyclotron radiation at B = 1.2T. Other interesting observations include: (1) enhanced e- cooling from collisions with H- cooled by neutrals; (2) enhanced damping of plasma waves due to e-<m:mfenced close="" open="/"><m:mphantom>:mpadded width="0pt">e-H-m:mpadded>:mfenced> H- collisional drag; (3) strong exponential damping of diocotron modes in a ``floppy'' nearly-pure H- plasma, created by rapid axial ejection of the electrons. Additional novel drift modes and instabilities are predicted theoretically in such a plasma. Supported by NSF/DoE Partnership Grants PHY-1414570 and DE-SC0008693.

Vocal characteristics of congenital anterior glottic webs in children: A case report.

PubMed

Shah, Jay; White, Katherine; Dohar, Joseph

2015-06-01

This case report describes a 5-year-old girl with chronic dysphonia and high-pitched voice since birth. Vocal quality was noted to be harsh. Videostroboscopy revealed significant hyperfunction and a Type II congenital anterior glottic web. Endoscopic division of the anterior glottic web was performed with significant improvement in vocal quality and quality of life. This paper describes methods of analyzing, diagnosing, and treating anterior glottic web with a focus on quality of life. Also, unique acoustic and aerodynamic voice features are identified. No other descriptions of a voice characteristic for anterior glottic web currently exist in the literature. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Study of the Histopathologic Characteristics and Surface Morphologies of Glottic Carcinomas With Anterior Vocal Commissure Involvement

PubMed Central

Wu, Jianhui; Zhao, Jing; Wang, Zhangfeng; Li, Zenghong; Luo, Jie; Liao, Bing; Yang, Zhiyun; Liu, Qihong; Wang, Bin; Wen, Weiping; Lei, Wenbin

2015-01-01

Abstract This article explores the features and the role of the anterior vocal commissure (AVC) structure and the surface morphologies of glottic carcinomas with AVC involvement to provide a reference for the selection of transoral carbon dioxide (CO2) laser surgery. A total of 31 cases of glottic carcinomas with AVC involvement from May 2012 to January 2014 were included. All patients underwent electronic laryngoscopic examinations and computed tomography scans to determine the surface morphology. After surgery, the tumor specimens were resected integrally, and axial serial sections parallel to the plane of vocal cords were taken to explore the features and possible invasion paths of the glottic carcinomas with AVC involvement. The rates of involvement of the supraglottis and subglottis were 71.4% and 14.8%, respectively, via the AVC. The involvement of the superficial layer of the unilateral or bilateral vocal cords without involvement of the vocal muscle in the AVC region (IVM) or the cartilage was present in 15 cases (48.4%). The involvement of the superficial layer of the unilateral and bilateral vocal cords occurred in 16 cases (51.6%) with the IVM in 13 cases and the involvement of the intermediate lamina of the thyroid cartilage (ITC) in 8 cases. The involvement of the ITC was associated with the involvement of the vocal muscle of the AVC region (P < 0.05). Among the pushing carcinomas, 15 of 21 (71.4%) presented with well-defined tumor mass, and 8 of 10 (80.0%) infiltrating carcinomas presented with multiple tumor nests that were often surrounded by fibrosis (P < 0.05). The AVC is an important path of invasion of subglottic in glottic carcinomas but less so for suparglottic. The Broyles’ ligaments acted as a barrier against the spread of the tumors to the thyroid cartilage, but this role was obviously weaken by the involvement of the vocal muscle of the AVC region. The infiltrating carcinomas presented with multiple tumor nests in fibrous tissue

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

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

Rosenthal, David I., E-mail: dirosenthal@mdanderson.or; Fuller, Clifton D.; Barker, Jerry L.

2010-06-01

Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapymore » consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.« less

Negative differential resistance in low Al-composition p-GaN/Mg-doped Al0.15Ga0.85N/n+-GaN hetero-junction grown by metal-organic chemical vapor deposition on sapphire substrate

NASA Astrophysics Data System (ADS)

Zhang, Kexiong; Liang, Hongwei; Shen, Rensheng; Wang, Dongsheng; Tao, Pengcheng; Liu, Yang; Xia, Xiaochuan; Luo, Yingmin; Du, Guotong

2014-02-01

Negative differential resistance (NDR) behavior was observed in low Al-composition p-GaN/Mg-doped-Al0.15Ga0.85N/n+-GaN hetero-junction grown by metal-organic chemical vapor deposition on sapphire substrate. The energy band and free carrier concentration of hetero-junction were studied by the model of the self-consistent solution of Schrödinger-Poisson equations combined with polarization engineering theory. At the forward bias of 0.95 V, the NDR effect has a high peak-to-valley current ratio of ˜9 with a peak current of 22.4 mA (˜current density of 11.4 A/cm2). An interesting phenomenon of NDR disappearance after consecutive scans and recurrence after electrical treatment was observed, which was associated with Poole-Frenkel effect.

Risk of Cerebrovascular Events in Elderly Patients After Radiation Therapy Versus Surgery for Early-Stage Glottic Cancer

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

Hong, Julian C.; Kruser, Tim J.; Gondi, Vinai

Purpose: Comprehensive neck radiation therapy (RT) has been shown to increase cerebrovascular disease (CVD) risk in advanced-stage head-and-neck cancer. We assessed whether more limited neck RT used for early-stage (T1-T2 N0) glottic cancer is associated with increased CVD risk, using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Methods and Materials: We identified patients ≥66 years of age with early-stage glottic laryngeal cancer from SEER diagnosed from 1992 to 2007. Patients treated with combined surgery and RT were excluded. Medicare CPT codes for carotid interventions, Medicare ICD-9 codes for cerebrovascular events, and SEER data for stroke as the causemore » of death were collected. Similarly, Medicare CPT and ICD-9 codes for peripheral vascular disease (PVD) were assessed to serve as an internal control between treatment groups. Results: A total of 1413 assessable patients (RT, n=1055; surgery, n=358) were analyzed. The actuarial 10-year risk of CVD was 56.5% (95% confidence interval 51.5%-61.5%) for the RT cohort versus 48.7% (41.1%-56.3%) in the surgery cohort (P=.27). The actuarial 10-year risk of PVD did not differ between the RT (52.7% [48.1%-57.3%]) and surgery cohorts (52.6% [45.2%-60.0%]) (P=.89). Univariate analysis showed an increased association of CVD with more recent diagnosis (P=.001) and increasing age (P=.001). On multivariate Cox analysis, increasing age (P<.001) and recent diagnosis (P=.002) remained significantly associated with a higher CVD risk, whereas the association of RT and CVD remained not statistically significant (HR=1.11 [0.91-1.37,] P=.31). Conclusions: Elderly patients with early-stage laryngeal cancer have a high burden of cerebrovascular events after surgical management or RT. RT and surgery are associated with comparable risk for subsequent CVD development after treatment in elderly patients.« less

Comparison of glottic visualisation and ease of intubation with different laryngoscope blades.

PubMed

Kulkarni, Atul P; Tirmanwar, Amar S

2013-03-01

Literature suggests glottic view is better with straight blades while tracheal intubation is easier with curved blades. To compare glottic view and ease of intubation with Macintosh, Miller, McCoy blades and the Trueview(®) laryngoscope. This prospective randomised study was undertaken in operation theatres of a 550 bedded tertiary referral cancer centre after approval from the Institutional Review Board. We compared the Macintosh, Miller, McCoy blades and the Trueview(®) laryngoscope for glottic visualisation and ease of tracheal intubation; in 120 patients undergoing elective cancer surgery; randomly divided into four groups. After induction of anaesthesia laryngoscopy was performed and trachea intubated. We recorded: Visualisation of glottis (Cormack Lehane grade), ease of intubation, number of attempts; need to change the blade and need for external laryngeal manipulation. Demographic data, Mallampati classification were compared using the Chi-square test. A P<0.05 was considered significant. Grade 1 view was obtained most often (87% patients) with Trueview(®) laryngoscope. Intubation was easier (Grade 1) with Trueview(®) and McCoy blades (93% each). Seven patients needed two attempts; one patient in Miller group needed three attempts. No patient in McCoy and Trueview(®) Groups required external laryngeal manipulation. We found that in patients with normal airway glottis was best visualised with Miller blade and Trueview(®) laryngoscope however, the trachea was more easily intubated with McCoy and Macintosh blades and Trueview(®) laryngoscope.

Quaternary M{sub 0.25}Cu{sub 0.25}Mg{sub 0.5}Fe{sub 2}O{sub 4} (M = Ni, Zn, Co, Mn) ferrite oxides: Synthesis, characterization and magnetic properties

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

Ciocarlan, Radu George; Laboratory of Adsorption and Catalysis, Department of Chemistry, University of Antwerpen; Pui, Aurel, E-mail: aurel@uaic.ro

2016-09-15

Highlights: • Superparamagnetic quaternary nanoferrite (M{sub 0.25}Cu{sub 0.25}Mg{sub 0.5}Fe{sub 2}O{sub 4,} where M = Mn, Zn, Co, Ni) were obtained. • C, O, H and metals were observed by XPS analysis. • Phases purity were confirmed by XRD diffraction and crystallite size (3–10 nm) were determind. - Abstract: We report the synthesis of M{sub 0.25}Cu{sub 0.25}Mg{sub 0.5}Fe{sub 2}O{sub 4} (where M = Mn, Zn, Co, Ni) nanoparticles using the coprecipitation method in the presence of carboxymethyl cellulose (CMC) as the in-situ surfactant. The crystalline structure and surface morphology were examined by means of X-ray diffraction (XRD) and scanning electron microscopymore » (SEM) and it was established that the average diameter of the magnetic nanoparticles (MNPs) is in the range of 3–10 nm. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) show that the MNPs are activated by the hydrophilic groups of the surfactant, which coat them and enhance their stability. The vibrating sample magnetometry measurements show the superparamagnetic behavior of the nanoparticles. Due to their small crystallite size, which implies large surface area, and their functionalization with organic groups, the obtained nanoparticles could have medical and catalytic applications.« less

Synthesis and electrochemical characterizations of spinel LiMn1.94MO4 (M = Mn0.06, Mg0.06, Si0.06, (Mg0.03Si0.03)) compounds as cathode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Zhao, Hongyuan; Liu, Xingquan; Cheng, Cai; Li, Qiang; Zhang, Zheng; Wu, Yue; Chen, Bing; Xiong, Weiqiang

2015-05-01

The spinel LiMn1.94MO4 (M = Mn0.06, Mg0.06, Si0.06, (Mg0.03Si0.03)) compounds are successfully synthesized by citric acid-assisted sol-gel method. The crystal structures and morphologies of synthesized compounds are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. All the compounds possess the cubic spinel structure of LiMn2O4 with space group of Fd-3m. The electrochemical properties of synthesized compounds are investigated by galvanostatic charge-discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results show that the Si-doping can increase the discharge capacity of LiMn2O4 due to the more expanded and regular MnO6 octahedra. In particular, for the LiMn1.94Mg0.03Si0.03O4 compound, the addition of Si4+ ions can make up for the shortage of Mg-doping in term of the discharge capacity. As a result, the Mg2+ and Si4+ co-doping has the effect of synergistic enhancement, which can make full use of the respective advantages of Mg-doping and Si-doping. The optimal LiMn1.94Mg0.03Si0.03O4 can deliver the initial discharge capacity of 128.3 mAh g-1 with good capacity retention of 92.8% after 100 cycles at 0.5 C in the voltage range of 3.20-4.35 V. Compared with the undoped LiMn2O4, the co-doped compound also presents superior rate performance, especially the capacity recovery performance.

pN0(i+) Breast Cancer: Treatment Patterns, Locoregional Recurrence, and Survival Outcomes

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

Karam, Irene; Breast Cancer Outcomes Unit, British Columbia Cancer Agency, Vancouver, BC; Lesperance, Maria F.

Purpose: To examine treatment patterns, recurrence, and survival outcomes in patients with pN0(i+) breast cancer. Methods and Materials: Subjects were 5999 women with AJCC (6th edition) pT1-3, pN0-N1a, M0 breast cancer diagnosed between 2003 and 2006. Of these, 4342 (72%) had pN0, 96 (2%) had pN0(i+), 349 (6%) had pNmic (micrometastases >0.2 mm to ≤2 mm), and 1212 (20%) had pN1a (1-3 positive macroscopic nodes) disease. Treatment characteristics and 5-year Kaplan-Meier local recurrence, regional recurrence (RR), locoregional recurrence (LRR), and overall survival were compared between nodal subgroups. Multivariable analysis was performed using Cox regression modeling. A 1:3 case-match analysis examinedmore » outcomes in pN0(i+) cases compared with pN0 controls matched for similar tumor and treatment characteristics. Results: Median follow-up was 4.8 years. Adjuvant systemic therapy use increased with nodal stage: 81%, 92%, 95%, and 94% in pN0, pN0(i+), pNmic, and pN1a disease, respectively (P<.001). Nodal radiation therapy (RT) use also increased with nodal stage: 1.7% in pN0, 27% in pN0(i+), 33% in pNmic, and 63% in pN1a cohorts (P<.001). Five-year Kaplan-Meier outcomes in pN0 versus pN0(i+) cases were as follows: local recurrence 1.7% versus 3.7% (P=.20), RR 0.5% versus 2.2% (P=.02), and LRR 2.1% versus 5.8% (P=.02). There were no RR events in 26 patients with pN0(i+) disease who received nodal RT and 2 RR events in 70 patients who did not receive nodal RT. On multivariable analysis, pN0(i+) was not associated with worse locoregional control or survival. On case-match analysis, LRR and overall survival were similar between pN0(i+) and matched pN0 counterparts. Conclusions: Nodal involvement with isolated tumor cells is not a significant prognostic factor for LRR or survival in this study's multivariable and case-match analyses. These data do not support the routine use of nodal RT in the setting of pN0(i+) disease. Prospective studies are needed to define

Estrogen receptor (α and β) but not androgen receptor expression is correlated with recurrence, progression and survival in post prostatectomy T3N0M0 locally advanced prostate cancer in an urban Greek population

PubMed Central

Megas, Georgios; Chrisofos, Michael; Anastasiou, Ioannis; Tsitlidou, Aida; Choreftaki, Theodosia; Deliveliotis, Charalampos

2015-01-01

The objective of this study was to evaluate the expression of estrogen receptors (ER(α) and ER(β)) and androgen receptors (ARs) as prognostic factors for biochemical recurrence, disease progression and survival in patients with pT3N0M0 prostate cancer (PCa) in an urban Greek population. A total of 100 consecutive patients with pT3N0M0 PCa treated with radical prostatectomy participated in the study. The mean age and follow-up were 64.2 and 6 years, respectively. The HSCORE was used for semi-quantitative analysis of the immunoreactivity of the receptors. The prognostic value of the ER(α) and ER(β) and AR was assessed in terms of recurrence, progression, and survival. AR expression was not associated with any of the above parameters; however, both ERs correlated with the prognosis. A univariate Cox regression analysis showed that ER(α) positive staining was significantly associated with a greater hazard for all outcomes. Increased ER(β) staining was significantly associated with a lower hazard for all outcomes in the univariate analysis. When both ER HSCORES were used for the analysis, it was found that patients with high ER(α) or low ER(β) HSCORES compared with patients with negatively stained ER(α) and >1.7 hSCORE ER(β) had 6.03, 10.93, and 10.53 times greater hazard for biochemical disease recurrence, progression of disease and death, respectively. Multiple Cox proportional hazard analyses showed that the age, preoperative prostate specific antigen, Gleason score and ERs were independent predictors of all outcomes. ER expression is an important prognosticator after radical prostatectomy in patients with pT3N0M0 PCa. By contrast, AR expression has limited prognostic value. PMID:25219910

Estrogen receptor (α and β) but not androgen receptor expression is correlated with recurrence, progression and survival in post prostatectomy T3N0M0 locally advanced prostate cancer in an urban Greek population.

PubMed

Megas, Georgios; Chrisofos, Michael; Anastasiou, Ioannis; Tsitlidou, Aida; Choreftaki, Theodosia; Deliveliotis, Charalampos

2015-01-01

The objective of this study was to evaluate the expression of estrogen receptors (ER(α) and ER(β)) and androgen receptors (ARs) as prognostic factors for biochemical recurrence, disease progression and survival in patients with pT3N0M0 prostate cancer (PCa) in an urban Greek population. A total of 100 consecutive patients with pT3N0M0 PCa treated with radical prostatectomy participated in the study. The mean age and follow-up were 64.2 and 6 years, respectively. The HSCORE was used for semi-quantitative analysis of the immunoreactivity of the receptors. The prognostic value of the ER(α) and ER(β) and AR was assessed in terms of recurrence, progression, and survival. AR expression was not associated with any of the above parameters; however, both ERs correlated with the prognosis. A univariate Cox regression analysis showed that ER(α) positive staining was significantly associated with a greater hazard for all outcomes. Increased ER(β) staining was significantly associated with a lower hazard for all outcomes in the univariate analysis. When both ER HSCORES were used for the analysis, it was found that patients with high ER(α) or low ER(β) HSCORES compared with patients with negatively stained ER(α) and >1.7 hSCORE ER(β) had 6.03, 10.93, and 10.53 times greater hazard for biochemical disease recurrence, progression of disease and death, respectively. Multiple Cox proportional hazard analyses showed that the age, preoperative prostate specific antigen, Gleason score and ERs were independent predictors of all outcomes. ER expression is an important prognosticator after radical prostatectomy in patients with pT3N0M0 PCa. By contrast, AR expression has limited prognostic value.

Energy efficient microwave synthesis of mesoporous Ce 0.5M 0.5O 2 (Ti, Zr, Hf) nanoparticles for low temperature CO oxidation in an ionic liquid – a comparative study

DOE PAGES

Alammar, Tarek; Chow, Ying -Kit; Mudring, Anja -Verena

2014-11-19

Ce 0.5M 0.5O 2 (M = Ti, Zr, Hf) nanoparticles have been successfully synthesized by microwave irradiation in the ionic liquid [C 4mim][Tf 2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide). The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N 2–adsorption measurements. XRD and Raman spectroscopy analyses confirmed the formation of solid solutions with cubic fluorite structure. The catalytic activities of the Ce 0.5M 0.5O 2 (M = Ti, Zr, Hf) nanoparticles were investigated in the low-temperature oxidation of CO. Ce 0.5Zr 0.5O 2 nanospheresmore » exhibit the best performance (100% conversion at 350 °C), followed by Ce 0.5Hf 0.5O 2 (55% conversion at 360 °C) and Ce 0.5Ti 0.5O 2 (11% conversion at 350 °C). Heating the as-prepared Ce 0.5Zr 0.5O 2 to 600 °C for extended time leads to a decrease in surface area and, as expected decreased catalytic activity. Depending on the ionic liquid the obtained Ce 0.5Zr 0.5O 2 exhibits different morphologies, varying from nano-spheres in [C 4mim][Tf 2N] and [P 66614][Tf 2N] (P 66614 = trishexyltetradecylphosphonium) to sheet-like assemblies in [C 3mimOH][Tf 2N] (C 3mimOH = 1-(3-hydroxypropyl)-3-methylimidazolium). As a result, the microwave synthesis superiority to other heating methods like sonochemical synthesis and conventional heating was proven by comparative experiments where the catalytic activity of Ce 0.5Zr 0.5O 2 obtained by alternate methods such as conventional heating was found to be poorer than that of the microwave-synthesised material.« less

Low-temperature transport properties of TaxN thin films (0.72 <= x <= 0.83)

NASA Astrophysics Data System (ADS)

Očko, Miroslav; Žonja, Sanja; Nelson, G. L.; Freericks, J. K.; Yu, Lei; Newman, N.

2010-11-01

We report on low-temperature (4-320 K) transport properties of TaxN thin films deposited on an amorphous SiO2 substrate. In this work, TaxN thin films were restricted to a narrow range of x: 0.72 <= x <= 0.83 yet show considerable and nonmonotonic variation of their transport properties with Ta concentration. This behaviour is consistent with a local minimum in the density of electronic states at the Fermi level, as calculated for the rock salt intermetallic Ta4N5, and a rigid band model for describing the transport. The temperature dependence of the resistivity is best fit to the unusual form exp(-T/T0). Interestingly enough, the fit parameter T0 correlates well with the temperature of the maximum of the corresponding thermopower. Both of these characteristics, the fit and the correlation with the thermopower, are consistent with the Jonson-Mahan many-body formalism for charge and thermal transport when one has a nontrivial temperature dependence of the chemical potential. At the lowest temperatures measured, we have also found that the resistivity and thermopower show signatures of electron-electron interactions. We discuss also our results in the light of some theories usually used for describing transport of thin films and to other experimental investigations that have been performed on TaxN.

Electrochemical performance and carbon deposition resistance of M-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (M = Pd, Cu, Ni or NiCu) anodes for solid oxide fuel cells

PubMed Central

Li, Meng; Hua, Bin; Pu, Jian; Chi, Bo; Jian, Li

2015-01-01

Pd-, Cu-, Ni- and NiCu-BaZr0.1Ce0.7Y0.1Yb0.1O3-δ anodes, designated as M-BZCYYb, were prepared by impregnating M-containing solution into BZCYYb scaffold, and investigated in the aspects of electrocatalytic activity for the reactions of H2 and CH4 oxidation and the resistance to carbon deposition. Impregnation of Pd, Ni or NiCu significantly reduced both the ohmic (RΩ) and polarization (RP) losses of BZCYYb anode exposed to H2 or CH4, while Cu impregnation decreased only RΩ in H2 and the both in CH4. Pd-, Ni- and NiCu-BZCYYb anodes were resistant to carbon deposition in wet (3 mol. % H2O) CH4 at 750°C. Deposited carbon fibers were observed in Pd- and Ni-BZCYYb anodes exposed to dry CH4 at 750°C for 12 h, and not observed in NiCu-BZCYYb exposed to dry CH4 at 750°C for 24 h. The performance of a full cell with NiCu-BZCYYb anode, YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ-Gd doped CeO2 (LSCF-GDC) cathode was stable at 750°C in wet CH4 for 130 h, indicating that NiCu-BZCYYb is a promising anode for direct CH4 solid oxide fuel cells (SOFCs). PMID:25563843

Influence of Europium Doping on Various Electrical Properties of Low-Temperature Sintered 0.5Ba0.90Ca0.10TiO3-0.5BaTi0.88Zr0.12O3-0.1%CuO- xEu Lead-Free Ceramics

NASA Astrophysics Data System (ADS)

Tian, Yongshang; Li, Shuiyun; Sun, Shulin; Gong, Yansheng; Li, Tiantian; Yu, Yongshang; Jing, Qiangshan

2018-01-01

0.5Ba0.90Ca0.10TiO3-0.5BaTi0.88Zr0.12O3-0.1%CuO- xEu (BCT-BZT-Cu- xEu; x = 0-0.90%) lead-free ceramics were sintered at 1220°C with as-synthesized nanoparticles by a modified Pechini method. The structural characteristics and electrical properties of the ceramics that were influenced by varying europium-doping were investigated. All the ceramics featured high densification (relative density: ˜ 96%). X-ray powder diffraction results indicated the samples possessed pure orthorhombic phase. The maximum relative permittivity ( ɛ r, 10869) was found at x around 0.30%. Europium ions could dope on different substitution sites in the ABO3 lattice, which evidently influenced electrical properties with various volumes of oxygen vacancy. Moreover, the formation mechanisms of oxygen vacancy and defect electron complexes were stated. The piezoelectric properties were impacted by defect electron complexes, internal stress, ionic electronegativity, etc. The optimal electrical properties, i.e., d 33 = 384 pC/N, Q m = 92, and k p = 0.36, were detected at x = 0.45%.

Oxygen adsorption on the Al0.25Ga0.75N (0001) surface: A first-principles study

NASA Astrophysics Data System (ADS)

Fu, Jiaqi; Song, Tielei; Liang, Xixia; Zhao, Guojun

2018-04-01

To understand the interaction mechanism for the oxygen adsorption on AlGaN surface, herein, we built the possible models of oxygen adsorption on Al0.25Ga0.75N (0001) surface. For different oxygen coverage, three kinds of adsorption site are considered. Then the favorable adsorption sites are characterized by first principles calculation for (2 × 2) supercell of Al0.25Ga0.75N (0001) surface. On basis of the optimal adsorption structures, our calculated results show that all the adsorption processes are exothermic, indicating that the (0001) surface orientation is active towards the adsorption of oxygen. The doping of Al is advantage to the adsorption of O atom. Additionally, the adsorption energy decreases with reducing the oxygen coverage, and the relationship between them is approximately linear. Owing to the oxygen adsorption, the surface states in the fundamental band gap are significant reduced with respect to the free Al0.25Ga0.75N (0001) surface. Moreover, the optical properties on different oxygen coverage are also discussed.

Relevant reduction effect with a modified thermoplastic mask of rotational error for glottic cancer in IMRT

NASA Astrophysics Data System (ADS)

Jung, Jae Hong; Jung, Joo-Young; Cho, Kwang Hwan; Ryu, Mi Ryeong; Bae, Sun Hyun; Moon, Seong Kwon; Kim, Yong Ho; Choe, Bo-Young; Suh, Tae Suk

2017-02-01

The purpose of this study was to analyze the glottis rotational error (GRE) by using a thermoplastic mask for patients with the glottic cancer undergoing intensity-modulated radiation therapy (IMRT). We selected 20 patients with glottic cancer who had received IMRT by using the tomotherapy. The image modalities with both kilovoltage computed tomography (planning kVCT) and megavoltage CT (daily MVCT) images were used for evaluating the error. Six anatomical landmarks in the image were defined to evaluate a correlation between the absolute GRE (°) and the length of contact with the underlying skin of the patient by the mask (mask, mm). We also statistically analyzed the results by using the Pearson's correlation coefficient and a linear regression analysis ( P <0.05). The mask and the absolute GRE were verified to have a statistical correlation ( P < 0.01). We found a statistical significance for each parameter in the linear regression analysis (mask versus absolute roll: P = 0.004 [ P < 0.05]; mask versus 3D-error: P = 0.000 [ P < 0.05]). The range of the 3D-errors with contact by the mask was from 1.2% - 39.7% between the maximumand no-contact case in this study. A thermoplastic mask with a tight, increased contact area may possibly contribute to the uncertainty of the reproducibility as a variation of the absolute GRE. Thus, we suggest that a modified mask, such as one that covers only the glottis area, can significantly reduce the patients' setup errors during the treatment.

Thermoelectric properties and chemical potential tuning by Cu-doping in n-type ionic conductors CuxAg2-xSe0.5Te0.5

NASA Astrophysics Data System (ADS)

Lee, Min Ho; Yun, Jae Hyun; Ahn, Kyunghan; Rhyee, Jong-Soo

2017-12-01

Copper and silver chalcogenides with superionic conduction behavior have shown impressively high ZT values, but there has been no intensive effort to optimize their carrier density to further improve their ZT values. Here, we prepared polycrystalline CuxAg2-xSe0.5Te0.5 (x = 0.01, 0.05, 0.1) samples using high temperature melting followed by hot-press sintering, and characterized their thermoelectric properties. We demonstrated that Cu substitution for Ag was achieved with <10% Cu content for CuxAg2-xSe0.5Te0.5 and the Cu doping was quite effective and significantly enhanced the compound's n-type carrier density, which was one order of magnitude higher than the pristine Ag2Se0.5Te0.5 (4.10 × 1018 cm-3). Impressively, the enhancement in electrical conductivity with increasing Cu content was greater than the decrease in absolute value of the Seebeck coefficient in the superionic conduction state. This led to relatively high power factors for Cu0.1Ag1.99Se0.5Te0.5, ranging between 1.10 and 1.30 mW m-1 K-2 over the broad temperature range of 400-560 K, and resulted in the highest ZT of 0.85 at 560 K. Furthermore, ZT values approached >0.7 over a wide temperature range of 460-560 K for x > 0.05. We suggest that the unusual Cu doping effect in Ag2Se0.5Te0.5 can be attributed to the creation of Cu ion conduction in addition to Ag ion conduction, and the optimization of the compound's n-type carrier density.

Cross sections of the 144Sm(n,α)141Nd and 66Zn(n,α)63Ni reactions at 4.0, 5.0 and 6.0 MeV

NASA Astrophysics Data System (ADS)

Yury, Gledenov; Guohui, Zhang; Khuukhenkhuu, Gonchigdorj; Milana, Sedysheva; Lubos, Krupa; Sansarbayar, Enkhbold; Igor, Chuprakov; Zhimin, Wang; Xiao, Fan; Luyu, Zhang; Huaiyong, Bai

2017-09-01

Cross sections of the 144Sm(n,α)141Nd and 66Zn(n,α)63Ni reactions were measured at En = 4.0, 5.0 and 6.0 MeV performed at the 4.5-MV Van de Graaff Accelerator of Peking University, China. A double-section gridded ionization chamber was used to detect the alpha particles. The foil samples of 144Sm2O3 and enriched 66Zn were placed at the common cathode plate of the chamber. Monoenergetic neutrons were produced by a deuterium gas target through the 2H(d,n)3He reaction. The neutron flux was monitored by a BF3 long counter. Cross sections of the 238U(n,f) reaction were used as the standard to perform the (n,α) reaction measurement. Present results are compared with existing measurements and evaluations. They are generally in agreement with TALYS-1.6 code calculations. For the 144Sm(n,α)141Nd reaction our measurements support the data of JEF-2.2. For the 66Zn(n,α)63Ni reaction present results support the data of EAF-2010 and TENDL-2015 data.

Evaluation of [99mTc/EDDA/HYNIC0]octreotide derivatives compared with [111In-DOTA0,Tyr3, Thr8]octreotide and [111In-DTPA0]octreotide: does tumor or pancreas uptake correlate with the rate of internalization?

PubMed

Storch, Daniel; Béhé, Martin; Walter, Martin A; Chen, Jianhua; Powell, Pia; Mikolajczak, Renata; Mäcke, Helmut R

2005-09-01

Radiolabeled somatostatin analogs are important tools for the in vivo localization and targeted radionuclide therapy of somatostatin receptor-positive tumors. The aim of this study was to compare 3 somatostatin analogs designed for the labeling with (99m)Tc (where HYNIC is 6-hydrazinopyridine-3-carboxylic acid): 6-hydrazinopyridine-3-carboxylic acid(0)-octreotide (HYNIC-OC/(99m)Tc-(1)), [HYNIC(0),Tyr(3)]octreotide (HYNIC-TOC/(99m)Tc-(2)), and [HYNIC(0),Tyr(3),Thr(8)]octreotide (HYNIC-TATE/(99m)Tc-(3)), using ethylenediamine-N,N'-diacetic acid (EDDA) as a coligand. In addition, we compared the (99m)Tc-labeled peptides [(111)In-diethylenetriaminepentaacetic acid(0)]octreotide ([(111)In-DTPA]-OC) and [(111)In-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid(0),Tyr(3),Thr(8)]octreotide ([(111)In-DOTA]-TATE) with regard to the rate of internalization and the biodistribution in AR4-2J (expressing the somatostatin receptor subtype 2) tumor-bearing rats. The main attention was directed toward a potential correlation between the rate of internalization and the tumor or pancreas uptake. Synthesis was performed on solid phase using a standard Fmoc strategy. Internalization was studied in cell culture (AR4-2J) and biodistribution was studied using a Lewis rat tumor model (AR4-2J). The 5 radiopeptides showed a specific internalization into AR4-2J cells in culture (as shown by blocking experiments). The rate of internalization of the 5 radiopeptides differed significantly according to the following order: (99m)Tc-(1) approximately = [(111)In-DTPA]-OC < (99m)Tc-(2) < (99m)Tc-(3) approximately = [(111)In-DOTA]-TATE. All radiopeptides displayed a rapid blood clearance and a fast clearance from all somatostatin receptor-negative tissues predominantly via the kidneys. A receptor-specific uptake of radioactivity was observed for all compounds in somatostatin receptor-positive organs such as the pancreas, the adrenals, and the stomach. After 4 h, the uptake in the AR4-2J tumor

Industry 4.0, M2m, Iot&S - All Equal?

NASA Astrophysics Data System (ADS)

Dobrin, Carmen

2014-11-01

Similarity between Industry 4.0, M2M, IOT&S. Advantages and disadvantages obtained using this three important methods. Decreasing costs while components are getting smaller and smaller in a world with better networking. Influence of business management applications integrated in smart factory logistic. The most important impacts in merging virtual and real production world, with the improvement of best processes having the same goal: creating value by open innovation

Selective layer disordering in intersubband Al 0.028Ga 0.972 N/AlN superlattices with silicon nitride capping layer

DOE PAGES

Wierer, Jonathan J.; Allerman, Andrew A.; Skogen, Erik J.; ...

2015-06-01

We demonstrate the selective layer disordering in intersubband Al 0.028Ga 0.972 N/AlN superlattices using a silicon nitride (SiN x) capping layer. The (SiN x) capped superlattice exhibits suppressed layer disordering under high-temperature annealing. In addition, the rate of layer disordering is reduced with increased SiN x thickness. The layer disordering is caused by Si diffusion, and the SiN x layer inhibits vacancy formation at the crystal surface and ultimately, the movement of Al and Ga atoms across the heterointerfaces. In conclusion, patterning of the SiN x layer results in selective layer disordering, an attractive method to integrate active and passivemore » III–nitride-based intersubband devices.« less

Electrodeless RF Plasma Thruster Using m = 0 Coil

NASA Astrophysics Data System (ADS)

Nishimura, Shuichi; Arai, Daisuke; Kuwahara, Daisuke; Shinohara, Shunjiro

2016-10-01

In order to realize a deep space exploration in the future, we have been developing a next generation electrodeless electric propulsion system by electromagnetic acceleration of high-density helicon plasma. A new proposed method by m = 0 coil plasma acceleration (m is an azimuthal mode number) is based on the Lorentz force: a product of the induced azimuthal current by supplying an AC current to the m = 0 coil and the radial component of the externally applied magnetic field (divergent field configuration). Here, we have investigated the dependences of an ion velocity and an electron density on the external parameters, leading to optimized conditions, using the SHD device. By increasing AC current on the order of 100 A, we could see the increase of ion velocity and electron density by a factor of 2.5 and 3, respectively.

pt5m - a 0.5 m robotic telescope on La Palma

NASA Astrophysics Data System (ADS)

Hardy, L. K.; Butterley, T.; Dhillon, V. S.; Littlefair, S. P.; Wilson, R. W.

2015-12-01

pt5m is a 0.5 m robotic telescope located on the roof of the 4.2 m William Herschel Telescope (WHT) building, at the Roque de los Muchachos Observatory, La Palma. Using a five-position filter wheel and CCD detector, and bespoke control software, pt5m provides a high-quality robotic observing facility. The telescope first began robotic observing in 2012, and is now contributing to transient follow-up and time-resolved astronomical studies. In this paper, we present the scientific motivation behind pt5m, as well as the specifications and unique features of the facility. We also present an example of the science we have performed with pt5m, where we measure the radius of the transiting exoplanet WASP-33b. We find a planetary radius of 1.603 ± 0.014RJ.

Effect of mandibular tori on glottic exposure during simulated suspension microlaryngoscopy.

PubMed

Best, Simon R; Kobler, James B; Friedman, Aaron D; Barbu, Anca M; Zeitels, Steven M; Burns, James A

2014-03-01

Mandibular tori have been identified as a contributing factor in difficult exposure during intubation. However, no investigation has measured the effect of mandibular tori on glottic exposure during suspension microlaryngoscopy (SML). The objective of this study was to measure how the size and location of mandibular tori affect glottic exposure during simulated SML at different thyromental distances. Suspension microlaryngoscopy was modeled on an anatomically accurate skull and larynx with thyromental distances between 6 and 12 cm. Mandibular tori were simulated by protruding screws 5 to 15 mm from the lingual aspect of the mandible. The tori were positioned either 15 mm (anterior) or 25 mm (posterior) from the midline of the symphysis. The glottic exposure for the various-size tori in each location was measured by recording the displacement of the glottiscope tip relative to the most anterior exposure achievable without tori. The glottiscope angle relative to the horizontal plane was measured for each condition. Mandibular tori of more than 10 mm had a significant impact on glottic exposure. Displacement of the glottiscope tip ranged from 2 to 9 mm for anteriorly placed tori and from 7 to 29 mm for posteriorly placed tori, with larger tori causing greater displacement. Increasing the thyromental distance increased the posterior glottiscope tip displacement regardless of torus size or location. The glottiscope angle increased with larger tori (12º to 28º), but this angle did not change with increasing thyromental distance. Larger size and more-posterior location of mandibular tori more significantly reduce glottic exposure during SML. The inner table of the mandible is the most relevant anatomic constraint on glottic exposure, which varies with the presence or absence of mandibular tori independent of thyromental distance.

Magnetocaloric effect and critical field analysis in Eu substituted La0.7-xEuxSr0.3MnO3 (x = 0.0, 0.1, 0.2, 0.3) manganites

NASA Astrophysics Data System (ADS)

Vadnala, Sudharshan; Asthana, Saket

2018-01-01

In this study, we have investigated magnetic behavior, magnetocaloric effect and critical exponent analysis of La0.7-xEuxSr0.3MnO3 (x = 0.0, 0.1, 0.2, 0.3) manganites synthesized through solid state reaction route. The crystallographic data obtained from refinement of X-ray diffraction patterns reveal that crystal structure changes from rhombohedral (for x = 0.0) to orthorhombic (for x ≥ 0.1). The average ionic radius of A-site is decreased from 1.384 Å (for x = 0.0) to 1.360 Å (for x = 0.3) with Eu3+ substitution which in turn decreases the Mn-O-Mn bond angles. Magnetization measurements are performed in the vicinity of TC to determine magnetocaloric effect (MCE) and critical field behavior. The maximum magnetic entropy change (Δ SMmax) (for μ0ΔH = 6T) increases with the Eu3+ substitution from 3.88 J/kg K (for x = 0.0) to 5.03 J/kg K (for x = 0.3) at the transition temperature. The critical field behaviour of compounds was analysed using various methods such as modified Arrott plots, Kouvel-Fisher method and critical isotherm to determine critical temperature and critical exponents (β, γ and δ). The obtained critical exponents are in good accordance with scaling relation. The temperature dependence of the order parameter n, for different magnetic fields, is studied using the relation ΔSMαHn. The values of n are found to obey the Curie-Weiss law for temperatures above the transition temperature. The rescaled change in entropy data for all compounds collapses into the same universal curve, revealing a second order phase transition.

Influence of the heterostructure design on the optical properties of GaN and Al0.1Ga0.9N quantum dots for ultraviolet emission

NASA Astrophysics Data System (ADS)

Matta, S.; Brault, J.; Ngo, T. H.; Damilano, B.; Korytov, M.; Vennéguès, P.; Nemoz, M.; Massies, J.; Leroux, M.; Gil, B.

2017-08-01

The optical properties of AlyGa1-yN quantum dots (QDs), with y = 0 or y = 0.1, in an AlxGa1-xN matrix are studied. The influence of the QD layer design is investigated pointing out the correlations between the QD structural and optical properties. In a first part, the role of the epitaxial strain in the dot self-assembling process is studied by fabricating GaN QD layers on different AlxGa1-xN layers with 0.5 ≤ x ≤ 0.7. Photoluminescence (PL) measurements show the main influence of the increase of the internal electric field (Fint) on the QD optical response inducing a strong red shift in the emission energy as x increases. Time resolved combined with temperature dependent PL measurements enabled the estimation of the QD internal quantum efficiencies at low temperature showing values around 50%. In addition, a PL integrated intensity ratio up to 74% is shown, between 300 and 9 K. In the second part, the design of Al0.1Ga0.9N QDs was investigated, by varying the Al0.1Ga0.9N amount deposited. An increase of the transition energy (from 3.65 eV up to 3.83 eV) is obtained while decreasing the deposited amount. Calculations of the ground state transition energies as a function of the Al0.1Ga0.9N dot height give a value of Fint around 2.0 ± 0.5 MV/cm. Therefore, the propensity of Al0.1Ga0.9N dots to emit at much higher energies than GaN dots (a PL shift of ˜1 eV using a low excitation power) is seen as the consequence of the reduced Fint together with their smaller sizes.

Reduction of the Mg acceptor activation energy in GaN, AlN, Al0.83Ga0.17N and MgGa δ-doping (AlN)5/(GaN)1: the strain effect

NASA Astrophysics Data System (ADS)

Jiang, Xin-He; Shi, Jun-Jie; Zhang, Min; Zhong, Hong-Xia; Huang, Pu; Ding, Yi-Min; He, Ying-Ping; Cao, Xiong

2015-12-01

To resolve the p-type doping problem of Al-rich AlGaN alloys, we investigate the influence of biaxial and hydrostatic strains on the activation energy, formation energy and band gap of Mg-doped GaN, AlN, Al0.83Ga0.17N disorder alloy and (AlN)5/(GaN)1 superlattice based on first-principles calculations by combining the standard DFT and hybrid functional. We find that the Mg acceptor activation energy {{E}\\text{A}} , the formation energy {{E}\\text{f}} and the band gap {{E}\\text{g}} decrease with increasing the strain ɛ. The hydrostatic strain has a more remarkable impact on {{E}\\text{g}} and {{E}\\text{A}} than the biaxial strain. Both {{E}\\text{A}} and {{E}\\text{g}} have a linear dependence on the hydrostatic strain. For the biaxial strain, {{E}\\text{g}} shows a parabolic dependence on ɛ if \\varepsilon ≤slant 0 while it becomes linear if \\varepsilon ≥slant 0 . In GaN and (AlN)5/(GaN)1, {{E}\\text{A}} parabolically depends on the biaxial compressive strain and linearly depends on the biaxial tensible strain. However, the dependence is approximately linear over the whole biaxial strain range in AlN and Al0.83Ga0.17N. The Mg acceptor activation energy in (AlN)5/(GaN)1 can be reduced from 0.26 eV without strain to 0.16 (0.22) eV with the hydrostatic (biaxial) tensible strain 3%.

Toxicological Assessment of ABATE (Tradename) (0,0,0’,0’-Tetramethyl-0,0’-Thio-Di-P-Phenylene Phosphorothioate) Administered Orally and Dermally to Mated and Nonmated Female Rabbits, April 1983.

DTIC Science & Technology

1983-11-02

such as gastroschisis, exencephaly, cleft palate ) are classified as abnormalities. Anomelies are considered to be minor varients from the normal, such as...and femurs not completely formed 1 Group VIII (IP-6-AN) 107 spina bifida 1 m microopthalmia 5 l cleft palate 3 0 talipes equinovarus 5 m... palate 1 m crantoschisis I m gastroschisis 1 webbed feet 1 m fused ribs 1 118 microopthalmia 3 m cleft palate 2 0 tallpes equtnovarus 1 0 120

PHOBOS AS A D-TYPE CAPTURED ASTEROID, SPECTRAL MODELING FROM 0.25 TO 4.0 μm

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

Pajola, M.; Magrin, S.; Bertini, I.

This paper describes the spectral modeling of the surface of Phobos in the wavelength range between 0.25 and 4.0 μm. We use complementary data to cover this spectral range: the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System on board the ESA Rosetta spacecraft) reflectance spectrum that Pajola et al. merged with the VSK-KRFM-ISM (Videospectrometric Camera (VSK)-Combined Radiometer and Photometer for Mars (KRFM)-Imaging Spectrometer for Mars (ISM) on board the USSR Phobos 2 spacecraft) spectra by Murchie and Erard and the IRTF (NASA Infrared Telescope Facility, Hawaii, USA) spectra published by Rivkin et al. The OSIRIS data allow the characterizationmore » of an area of Phobos covering from 86.°8 N to 90° S in latitude and from 126° W to 286° W in longitude. This corresponds chiefly to the trailing hemisphere, but with a small sampling of the leading hemisphere as well. We compared the OSIRIS results with the Trojan D-type asteroid 624 Hektor and show that the overall slope and curvature of the two bodies over the common wavelength range are very similar. This favors Phobos being a captured D-type asteroid as previously suggested. We modeled the OSIRIS data using two models, the first one with a composition that includes organic carbonaceous material, serpentine, olivine, and basalt glass, and the second one consisting of Tagish Lake meteorite and magnesium-rich pyroxene glass. The results of these models were extended to longer wavelengths to compare the VSK-KRFM-ISM and IRTF data. The overall shape of the second model spectrum between 0.25 and 4.0 μm shows curvature and an albedo level that match both the OSIRIS and Murchie and Erard data and the Rivkin et al. data much better than the first model. The large interval fit is encouraging and adds weight to this model, making it our most promising fit for Phobos. Since Tagish Lake is commonly used as a spectral analog for D-type asteroids, this provides additional support for compositional

Influence of template properties and quantum well number on stimulated emission from Al0.7Ga0.3N/Al0.8Ga0.2N quantum wells

NASA Astrophysics Data System (ADS)

Jeschke, J.; Martens, M.; Hagedorn, S.; Knauer, A.; Mogilatenko, A.; Wenzel, H.; Zeimer, U.; Enslin, J.; Wernicke, T.; Kneissl, M.; Weyers, M.

2018-03-01

AlGaN multiple quantum well laser heterostructures for emission around 240 nm have been grown by metalorganic vapor phase epitaxy on epitaxially laterally overgrown (ELO) AlN/sapphire templates. The edge emitting laser structures showed optically pumped lasing with threshold power densities in the range of 2 MW cm-2. The offcut angle of the sapphire substrates as well as the number and the width of the quantum wells were varied while keeping the total thickness of the gain region constant. A larger offcut angle of 0.2° leads to step bunching on the surface as well as Ga accumulation at the steps, but also to an increased inclination of threading dislocations and coalescence boundaries resulting in a reduced dislocation density and thus a reduced laser threshold in comparison to lasers grown on ELO with an offcut of 0.1°. For low losses, samples with fewer QWs exhibited a lower lasing threshold due to a reduced transparency pump power density while for high losses, caused by a higher threading dislocation density, the quadruple quantum well was favorable due to its higher maximum gain.

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.

Feasibility and diagnostic performance of dual-tracer-guided sentinel lymph node biopsy in cT1-2N0M0 gastric cancer: a systematic review and meta-analysis of diagnostic studies.

PubMed

Huang, Ling; Wei, Tao; Chen, Junjun; Zhou, Donghui

2017-05-16

Dual-tracer-guided sentinel lymph node (SLN) biopsy may provide a promising diagnostic tool to assess accurately the status of lymph node metastasis in the surgical operation and assure the oncologic safety of the function or stomach preserving surgery. The diagnostic performance of this technology in recent studies varied. Thus, we conducted this meta-analysis. This systematic review and meta-analysis was registered at the PROSPERO. Eligible studies were searched in the PubMed, EMBASE, Web of Knowledge, and Cochrane Library databases. A random-effect model was used to pool the data. Summary receiver operator characteristic curves, analysis for publication bias, meta-regression, and subgroup analysis were also performed. The pooled SLN identification rate and sensitivity were 0.97 and 0.89. 99m Tc-human serum albumin with indocyanine green (ICG), 99m Tc-antimony sulfur colloid with ICG, performing SLN biopsy ≥15 min after dye injection, an SLN ≥5, the basin dissection, laparoscopic surgery, in studies conducted in Japan and studies published after 2012, were associated with higher sensitivity. CT1 stage, performing SLN biopsy ≥15 min after dye injection, in studies conducted in Japan and studies published after 2012, were related with a higher identification rate. Dual tracer is promising in SLN biopsy in gastric cancer, and the clinical application of SLN biopsy should be limited to the patients of cT1N0M0 gastric cancer. The combination of 99m Tc-human serum albumin and ICG as well as the combination of 99m Tc-antimony sulfur colloid and ICG may be the optimal tracer combination. However, it seems not justified to put this technique into routine clinical application recently. Some factors that might enhance diagnostic value are identified.

Perovskite-type La0.8Sr0.2Co0.8Fe0.2O3 with uniform dispersion on N-doped reduced graphene oxide as an efficient bi-functional Li-O2 battery cathode.

PubMed

Cheng, Junfang; Jiang, Yuexing; Zhang, Ming; Zou, Lu; Huang, Yizhen; Wang, Ziling; Chi, Bo; Pu, Jian; Li, Jian

2017-04-19

A composite cathode including N-rGO with homogeneously dispersed perovskite La 0.8 Sr 0.2 Co 0.8 Fe 0.2 O 3 on the surface is studied. Li-O 2 batteries with LSCF@N-rGO cathode show better performance than those with LSCF-SP or N-rGO cathode. EIS and morphology analysis indicate that LSCF is beneficial to remold the shape of Li 2 O 2 and catalyze the decomposition of Li 2 O 2 .

Pretreatment of shale gas drilling flowback fluid (SGDF) by the microscale Fe0/persulfate/O3 process (mFe0/PS/O3).

PubMed

Zhang, Heng; Xiong, Zhaokun; Ji, Fangzhou; Lai, Bo; Yang, Ping

2017-06-01

Shale gas drilling flowback fluid (SGDF) generated during shale gas extraction is of great concern due to its high total dissolved solid, radioactive elements and organic matter. To remove the toxic and refractory pollutants in SGDF and improve its biodegradability, a microsacle Fe 0 /Persulfate/O 3 process (mFe 0 /PS/O 3 ) was developed to pretreat this wastewater obtained from a shale gas well in southwestern China. First, effects of mFe 0 dosage, O 3 flow rate, PS dosage, pH values on the treatment efficiency of mFe 0 /PS/O 3 process were investigated through single-factor experiments. Afterward, the optimal conditions (i.e., pH = 6.7, mFe 0 dosage = 6.74 g/L, PS = 16.89 mmol/L, O 3 flow rate = 0.73 L/min) were obtained by using response surface methodology (RSM). Under the optimal conditions, high COD removal (75.3%) and BOD 5 /COD ratio (0.49) were obtained after 120 min treatment. Moreover, compared with control experiments (i.e., mFe 0 , O 3 , PS, mFe 0 /O 3 , mFe 0 /PS, O 3 /PS), mFe 0 /PS/O 3 system exerted better performance for pollutants removal in SGDF due to strong synergistic effect between mFe 0 , PS and O 3 . In addition, the decomposition or transformation of the organic pollutants in SGDF was analyzed by using GC-MS. Finally, the reaction mechanism of the mFe 0 /PS/O 3 process was proposed according to the analysis results of SEM-EDS and XRD. It can be concluded that high-efficient mFe 0 /PS/O 3 process was mainly resulted from the combination effect of direct oxidation by ozone and persulfate, heterogeneous and homogeneous catalytic oxidation, Fenton-like reaction and adsorption. Therefore, mFe 0 /PS/O 3 process was proven to be an effective method for pretreatment of SGDF prior to biological treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Galaxy And Mass Assembly (GAMA): the 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 μm to 1 mm

NASA Astrophysics Data System (ADS)

Driver, S. P.; Robotham, A. S. G.; Kelvin, L.; Alpaslan, M.; Baldry, I. K.; Bamford, S. P.; Brough, S.; Brown, M.; Hopkins, A. M.; Liske, J.; Loveday, J.; Norberg, P.; Peacock, J. A.; Andrae, E.; Bland-Hawthorn, J.; Bourne, N.; Cameron, E.; Colless, M.; Conselice, C. J.; Croom, S. M.; Dunne, L.; Frenk, C. S.; Graham, Alister W.; Gunawardhana, M.; Hill, D. T.; Jones, D. H.; Kuijken, K.; Madore, B.; Nichol, R. C.; Parkinson, H. R.; Pimbblet, K. A.; Phillipps, S.; Popescu, C. C.; Prescott, M.; Seibert, M.; Sharp, R. G.; Sutherland, W. J.; Taylor, E. N.; Thomas, D.; Tuffs, R. J.; van Kampen, E.; Wijesinghe, D.; Wilkins, S.

2012-12-01

We use the Galaxy And Mass Assembly survey (GAMA) I data set combined with GALEX, Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) imaging to construct the low-redshift (z < 0.1) galaxy luminosity functions in FUV, NUV, ugriz and YJHK bands from within a single well-constrained volume of 3.4 × 105 (Mpc h-1)3. The derived luminosity distributions are normalized to the SDSS data release 7 (DR7) main survey to reduce the estimated cosmic variance to the 5 per cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 μm free from any wavelength-dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population, respectively. Using the Driver et al. prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 ± 0.3) × 1035 h W Mpc-3 of which (1.2 ± 0.1) × 1035 h W Mpc-3 is directly released into the inter-galactic medium and (0.6 ± 0.1) × 1035 h W Mpc-3 is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid- and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post-dust attenuated energy output of the nearby Universe from 0.1 μm to 0.6 mm. The largest uncertainty in this measurement lies in the mid- and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass and morphology.

Management of Posterior Glottic Stenosis using the Combined Glottic Reconstruction Procedure.

PubMed

Nouraei, S A R; Dorman, E B; Vokes, D E

2018-05-29

Laryngotracheal stenosis secondary to Bilateral Vocal Fold Mobility Impairment (BVFMI) is a challenging condition to treat. The glottic aperture accounts for 25% of the respiratory resistance 1 and BVFMI prevents its breath-by-breath regulation, causing severe airway compromise. Moreover, since the larynx is also the organ of phonation and its reflexive closure during swallowing is the principal airway protective mechanism, improving airway may worsen dysphonia, dysphagia, and aspiration. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Emergence and expansion of cosmic space as due to M0-branes

NASA Astrophysics Data System (ADS)

Sepehri, Alireza; Setare, Mohammad Reza; Capozziello, Salvatore

2015-12-01

Recently, Padmanabhan (arXiv:1206.4916 [hep-th]) discussed that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region causes the accelerated expansion of the universe. The main question arising is: what is the origin of this inequality between the surface degrees of freedom and the bulk degrees of freedom? We answer this question in M-theory. In our model, first M0-branes are compactified on one circle and N D0-branes are created. Then N D0-branes join each other, grow, and form one D5-branes. Next, the D5-brane is compactified on two circles and our universe's D3-brane, two D1-branes and some extra energies are produced. After that, one of the D1-branes, which is closer to the universe's brane, gives its energy into it, and this leads to an increase in the difference between the numbers of degrees of freedom and the occurring inflation era. With the disappearance of this D1-brane, the number of degrees of freedom of boundary surface and bulk region become equal and inflation ends. At this stage, extra energies that are produced due to the compactification cause an expansion of the universe and deceleration epoch. Finally, another D1-brane dissolves in our universe's brane, leads to an inequality between degrees of freedom, and there occurs a new phase of acceleration.

Postearthquake relaxation and aftershock accumulation linearly related after the 2003 M 6.5 Chengkung, Taiwan, and the 2004 M 6.0 Parkfield, California, earthquakes

USGS Publications Warehouse

Savage, J.C.; Yu, S.-B.

2007-01-01

We treat both the number of earthquakes and the deformation following a mainshock as the superposition of a steady background accumulation and the post-earthquake process. The preseismic displacement and seismicity rates ru and rE are used as estimates of the background rates. Let t be the time after the mainshock, u(t) + u0 the postseismic displacement less the background accumulation rut, and ??N(t) the observed cumulative number of postseismic earthquakes less the background accumulation rE t. For the first 160 days (duration limited by the occurrence of another nearby earthquake) following the Chengkung (M 6.5, 10 December 2003, eastern Taiwan) and the first 560 days following the Parkfield (M 6.0, 28 September 2004, central California) earthquakes u(t) + u0 is a linear function of ??N(t). The aftershock accumulation ??N(t) for both earthquakes is described by the modified Omori Law d??N/dt ?? (1 + t/??)-p with p = 0.96 and ?? = 0.03 days. Although the Chengkung earthquake involved sinistral, reverse slip on a moderately dipping fault and the Parkfield earthquake right-lateral slip on a near-vertical fault, the earthquakes share an unusual feature: both occurred on faults exhibiting interseismic fault creep at the surface. The source of the observed postseismic deformation appears to be afterslip on the coseismic rupture. The linear relation between u(t) + u0 and N(t) suggests that this afterslip also generates the aftershocks. The linear relation between u(t) + u0 and ??N(t) obtains after neither the 1999 M 7.1 Hector Mine (southern California) nor the 1999 M 7.6 Chi-Chi (central Taiwan) earthquakes, neither of which occurred on fault segments exhibiting fault creep.

Lithium-Rich Nanoscale Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 Cathode Material Prepared by Co-Precipitation Combined Freeze Drying (CP-FD) for Lithium-Ion Batteries

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

Bai, Ying; Li, Yu; Wu, Chuan

Nanoscale Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 material is synthesized by a co-precipitation combined freeze drying (CP-FD) method, and compared with a conventional co-precipitation method combined vacuum drying (CP-VD). With the combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM), it is found that the sample from CP-FD method consists of a pure phase with good crystallinity and small, homogenous particles (100-300 nm) with uniform particle size distribution. Inductively coupled plasma spectroscopy (ICP) shows that the sample has a stoichiometric ratio of n((Li)): n((Mn)): n((Ni)): n((Co))=9: 4: 1: 1; and its Brunauer-Emmett-Teller (BET) specific surface area is 5.749 m(2)g(-1). This sample achieves excellentmore » electrochemical properties: its initial discharge capacities are 298.9 mAhg(-1) at 0.1C (20 mAg(-1)), 246.1 mAhg(-1) at 0.5C, 215.8 mAhg(-1) at 1C, and 154.2 mAhg(-1) at 5C (5C charge and 5C discharge), as well as good cycling performance. In addition, the Li+ chemical diffusion coefficient of Li1.2Mn0.54Ni0.13Co0.13O2 material prepared by the CP-FD method is 4.59 x 10(-11) cm(2) s(-1), which is higher than that of the Li1.2Mn0.54Ni0.13Co0.13O2 material prepared by CP-VD. This phenomenon illustrates the potential for Li1.2Mn0.54Ni0.13Co0.13O2 with good rate performance synthesized by CP-FD method.« less

Perovskites Bi0.8La0.2FeO3 and Bi0.8La0.2Fe0.95Cr0.05O3: Crystal structure and magnetic and charge states of iron ions

NASA Astrophysics Data System (ADS)

Sigov, A. S.; Pokatilov, V. S.; Makarova, A. O.; Pokatilov, V. V.

2014-06-01

Perovskites of the Bi0.8La0.2Fe1 - x Cr x O3 system ( x = 0, 0.05) were investigated by Mössbauer spectroscopy in the temperature range of 298-800 K. The samples were fabricated by solid-state synthesis and had a rhombic structure. Iron ions in Bi0.8La0.2FeO3 and Bi0.8La0.2Fe0.95Cr0.05O3 are situated in trivalent states. The magnetic transition temperatures (the Néel temperatures T N ) T N = 677.5 ± 2.5 K for Bi0.8La0.2FeO3 and T N = 647.6 ± 2.5 K for Bi0.8La0.2Fe0.95Cr0.05O3 are measured. The substitution of trivalent iron ions from trivalent chromium ions in the amount x = 0.05 in Bi0.8La0.2Fe0.95Cr0.05O3 perovskite decreases the hyperfine magnetic field at nuclei 57Fe in Fe+3-O-Cr+3 chains by 30 kOe.

Cross Section Measurement for the 95Mo(n, {alpha})92Zr Reaction at 4.0, 5.0 and 6.0 MeV

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

Zhang, Guohui; Wu, Hao; Zhang, Jiaguo

2011-01-01

For the {sup 95}Mo(n, {alpha}){sup 92}Zr reaction cross section, there is only one experimental datum in the MeV neutron energy region with large uncertainty. As a result, very large deviations exist in different evaluated nuclear data libraries. This paper report the measurement of cross sections of the {sup 95}Mo(n, {alpha}){sup 92}Zr reaction at En = 4.0, 5.0 and 6.0 MeV. Experiments were performed at the 4.5 MV Van de Graaff of Peking University, China. A twin gridded ionization chamber was used as alpha particle detector and two large area {sup 95}Mo samples placed back to back were adopted. Fast neutronsmore » were produced through the D(d, n){sup 3}He reaction by using a deuterium gas target. A small {sup 238}U fission chamber was adopted for absolute neutron flux determination and a BF{sub 3} long counter was used for neutron flux monitor. Present experimental data are compared with existing evaluations and measurement.« less

Lattice damage and compositional changes in Xe ion irradiated InxGa1-xN (x = 0.32-1.0) single crystals

DOE PAGES

Zhang, Limin; Jiang, Weilin; Dissanayake, Amila C.; ...

2016-06-27

Lattice disorder and compositional changes in InxGa1-xN (x=0.32, 0.47, 0.7, 0.8 and 1.0) films on GaN/Al2O3 substrates, induced by room-temperature irradiation of 5 MeV Xe ions, have been investigated using both Rutherford backscattering spectrometry under ion-channeling conditions and time-of-flight secondary ion mass spectrometry. The results show that for a fluence of 3E13 cm-2, the relative level of lattice disorder in InxGa1-xN increases monotonically from 59% to 90% with increasing indium concentration x from 0.32 to 0.7; a further increase in x up to 1.0 leads to little increase in the disorder level. In contrast to Ga-rich InxGa1-xN (x=0.32 and 0.47),more » significant volume swelling of up to ~25% accompanied with oxidation in In-rich InxGa1-xN (x=0.7, 0.8 and 1.0) is observed. In addition, irradiation-induced atomic mixing occurs at the interface of In-rich InxGa1-xN and GaN. The results from this study indicate an extreme susceptibility of the high In-content InxGa1-xN to heavy-ion irradiation, and suggest that cautions must be exercised in applying ion-implantation techniques to these materials at room temperature. Further studies of the irradiation behavior at elevated temperatures are warranted.« less

Calorimetric Investigation of Thermal Stability of 304H Cu (Fe-17.7Cr-9.3Ni-2.95Cu-0.91Mn-0.58Nb-0.24Si-0.1C-0.12N-Wt Pct) Austenitic Stainless Steel

NASA Astrophysics Data System (ADS)

Tripathy, Haraprasanna; Subramanian, Raju; Hajra, Raj Narayan; Rai, Arun Kumar; Rengachari, Mythili; Saibaba, Saroja; Jayakumar, Tammana

2016-12-01

The sequence of phase instabilities that take place in a Fe-17.7Cr-9.3Ni-0.58Nb-2.95Cu-0.12N (wt pct) austenitic stainless steel (304H Cu grade) as a function of temperature has been investigated using dynamic calorimetry. The results obtained from this investigation are supplemented by Thermocalc-based equilibrium and Scheil-Gulliver nonequilibrium solidification simulation. The following phase transformation sequence is found upon slow cooling from liquid: L → L + γ → L + γ + MX → γ + MX + δ → γ +MX + M23C6 → γ + MX + M23C6 + Cu. Under slow cooling, the solidification follows austenite + ferrite (AF) mode, which is in accordance with Thermocalc prediction and Scheil-Gulliver simulation. However, higher cooling rates result in skeletal δ-ferrite formation, due to increased segregation tendency of Nb and Cr to segregate to interdendritic liquid. The solidification mode is found to depend on combined Nb + Cu content. Experimental estimates of enthalpy change associated with melting and secondary phase precipitation are also obtained. In addition a semi-quantitative study on the dissolution kinetics of M23C6 type carbides has also been investigated. The standard solution treatment at 1413 K (1140 °C) is found to be adequate to dissolve both Cu and M23C6 into γ-austenite; but the complete dissolution of MX type carbonitrides occurs near the melting region.

Measurement of D0 Azimuthal Anisotropy at Midrapidity in Au +Au Collisions at √{sN N }=200 GeV

NASA Astrophysics Data System (ADS)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

2017-05-01

We report the first measurement of the elliptic anisotropy (v2) of the charm meson D0 at midrapidity (|y |<1 ) in Au +Au collisions at √{sN N}=200 GeV . The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D0 v2 in 0%-80% centrality Au +Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (pT) of less than 4 GeV /c . The D0 v2 as a function of transverse kinetic energy (mT-m0, where mT=√{pT2+m02 }) is consistent with that of light mesons in 10%-40% centrality Au +Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2 π T Ds) in the range of ˜2 - 12 , are able to simultaneously reproduce our D0 v2 result and our previously published results for the D0 nuclear modification factor.

Functionalization of ( n, 0) CNTs ( n = 3-16) by uracil: DFT studies

NASA Astrophysics Data System (ADS)

Mirzaei, Mahmoud; Harismah, Kun; Jafari, Elham; Gülseren, Oğuz; Rad, Ali Shokuhi

2018-01-01

Density functional theory (DFT) calculations were performed to investigate stabilities and properties for uracil (U)-functionalized carbon nanotubes (CNTs). To this aim, the optimized molecular properties were evaluated for ( n, 0) models of CNTs ( n = 3-16) in the original and U-functionalized forms. The results indicated that the dipole moments and energy gaps were independent of tubular diameters whereas the binding energies showed that the U-functionalization could be better achieved for n = 8-11 curvatures of ( n, 0) CNTs. Further studies based on the evaluated atomic-scale properties, including quadrupole coupling constants ( C Q ), indicated that the electronic properties of atoms could detect the effects of diameters variations of ( n, 0) CNTs, in which the effects were very much significant for the atoms around the U-functionalization regions. Finally, the achieved results of singular U, original CNTs, and CNT-U hybrids were compared to each other to demonstrate the stabilities and properties for the U-functionalized ( n, 0) CNTs.

100-W 105-μm 0.15NA fiber coupled laser diode module

NASA Astrophysics Data System (ADS)

Karlsen, Scott R.; Price, R. Kirk; Reynolds, Mitch; Brown, Aaron; Mehl, Ron; Patterson, Steve; Martinsen, Robert J.

2009-02-01

We report on the development of a high brightness laser diode module capable of coupling over 100W of optical power into a 105 μm 0.15 NA fiber at 976 nm. This module, based on nLIGHT's Pearl product architecture, utilizes hard soldered single emitters packaged into a compact and passively-cooled package. In this system each diode is individually collimated in the fast and slow axes and free-space coupled into a single fiber. The high brightness module has an optical excitation under 0.13 NA, is virtually free of cladding modes, and has an electrical to optical efficiency greater than 40%. Additionally, this module is compatible with high power 7:1 fused fiber combiners, and initial experiments demonstrated 500W coupled into a 220 μm, 0.22 NA fiber. These modules address the need in the market for higher brightness diode lasers for pumping fiber lasers and direct material processing.

Cross sections of the {sup 67}Zn(n,{alpha}){sup 64}Ni reaction at 4.0, 5.0, and 6.0 MeV

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

Zhang Guohui; Liu Jiaming; Wu Hao

2010-11-15

Experimental cross section data of the {sup 67}Zn(n,{alpha}){sup 64}Ni reaction are very scanty because the residual nucleus {sup 64}Ni is stable and the commonly used activation method is not feasible. As a result, very large deviations (about 10 times) exist among different nuclear data libraries. In the present work, cross sections of the partial {sup 67}Zn(n,{alpha}{sub 0}){sup 64}Ni and total {sup 67}Zn(n,{alpha}){sup 64}Ni reactions are measured at neutron energies of 4.0 and 5.0 MeV for the first time, and those of 6.0 MeV are remeasured for consistency checking. A twin-gridded ionization chamber was used as the charged-particle detector and twomore » enriched back-to-back-set {sup 67}Zn samples were adopted. Experiments were performed at the 4.5 MV Van de Graaff Accelerator of Peking University. Neutrons were produced through the {sup 2}H(d,n){sup 3}He reaction using a deuterium gas target. Absolute neutron flux was determined by counting the fission fragments from a {sup 238}U sample placed inside the gridded ionization chamber while a BF{sub 3} long counter was employed as neutron flux monitor. Present data are compared with results of previous measurements, evaluations, and talys code calculations.« less

Surface morphology of Al0.3Ga0.7N/Al2O3-high electron mobility transistor structure.

PubMed

Cörekçi, S; Usanmaz, D; Tekeli, Z; Cakmak, M; Ozçelik, S; Ozbay, E

2008-02-01

We present surface properties of buffer films (AIN and GaN) and Al0.3Gao.zN/Al2O3-High Electron Mobility Transistor (HEMT) structures with/without AIN interlayer grown on High Temperature (HT)-AIN buffer/Al2O3 substrate and Al2O3 substrate. We have found that the GaN surface morphology is step-flow in character and the density of dislocations was about 10(8)-10(9) cm(-2). The AFM measurements also exhibited that the presence of atomic steps with large lateral step dimension and the surface of samples was smooth. The lateral step sizes are in the range of 100-250 nm. The typical rms values of HEMT structures were found as 0.27, 0.30, and 0.70 nm. HT-AIN buffer layer can have a significant impact on the surface morphology of Al0.3Ga0.7N/Al2O3-HEMT structures.

A 256 pixel magnetoresistive biosensor microarray in 0.18μm CMOS

PubMed Central

Hall, Drew A.; Gaster, Richard S.; Makinwa, Kofi; Wang, Shan X.; Murmann, Boris

2014-01-01

Magnetic nanotechnologies have shown significant potential in several areas of nanomedicine such as imaging, therapeutics, and early disease detection. Giant magnetoresistive spin-valve (GMR SV) sensors coupled with magnetic nanotags (MNTs) possess great promise as ultra-sensitive biosensors for diagnostics. We report an integrated sensor interface for an array of 256 GMR SV biosensors designed in 0.18 μm CMOS. Arranged like an imager, each of the 16 column level readout channels contains an analog front- end and a compact ΣΔ modulator (0.054 mm2) with 84 dB of dynamic range and an input referred noise of 49 nT/√Hz. Performance is demonstrated through detection of an ovarian cancer biomarker, secretory leukocyte peptidase inhibitor (SLPI), spiked at concentrations as low as 10 fM. This system is designed as a replacement for optical protein microarrays while also providing real-time kinetics monitoring. PMID:24761029

Optical absorption and photoluminescence study of nanocrystalline Zn0.92M0.08O (M: Li & Gd)

NASA Astrophysics Data System (ADS)

Punia, Khushboo; Lal, Ganesh; Kumar, Sudhish

2018-05-01

Nanocrystalline samples of Zn0.92Li0.08O and Zn0.92Gd0.08O have been synthesized using citrate sol-gel route without post synthesis annealing and characterized using powder X-ray diffraction (XRD), UV-Vis-NIR and Photoluminescence spectroscopic measurements. Analysis of XRD pattern and PL spectra revealed single phase formation of the nanocrystalline Zn0.92Li0.08O and Zn0.92Gd0.08O in the wurtzite type hexagonal structure with intrinsic crystal and surface defects. UV-Vis-NIR optical absorption measurements show that the maximum photo absorption occurs below 600nm in the UV& visible band. The estimated values of band gap energy were found to be 2.53eV and 2.73eV for Zn0.92Li0.08O and Zn0.92Gd0.08O respectively. The photoluminescence spectra excited at the wavelength 325nm displays two broad peaks in the UV and visible bands centered at ˜416 nm & ˜602 nm for Zn0.92Gd0.08O and ˜406nm & ˜598nm for Zn0.92Li0.08O. Both Gd and Li doping in ZnO leads to considerable decrease in the optical band gap energy and red shifting of the UV emission band towards the visible band.

Defect reduction in Si-doped Al{sub 0.45}Ga{sub 0.55}N films by SiN{sub x} interlayer method

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

Li, Yang; Chen, Shengchang; Kong, Man

2014-01-28

The dislocation density in AlGaN epitaxial layers with Al content as high as 45% grown on sapphire substrates has been effectively reduced by introducing an in-situ deposited SiN{sub x} nanomask layer in this study. By closely monitoring the evolution of numerous material properties, such as surface morphology, dislocation density, photoluminescence, strain states, and electron mobility of the Si-Al{sub 0.45}Ga{sub 0.55}N layers as the functions of SiN{sub x} interlayer growth time, the surface coverage fraction of SiN{sub x} is found to be a crucial factor determining the strain states and dislocation density. The dependence of the strain states and the dislocationmore » density on the surface coverage fraction of SiN{sub x} nanomask supports the very different growth models of Al-rich AlGaN on SiN{sub x} interlayer due to the reduced nucleation selectivity compared with the GaN counterpart. Compared with GaN, which can only nucleate at open pores of SiN{sub x} nanomask, Al-rich AlGaN can simultaneously nucleate at both open pores and SiN{sub x} covered areas. Dislocations will annihilate at the openings due to the 3D growth initiated on the opening area, while 2D growth mode is preserved on SiN{sub x} and the threading dislocations are also preserved. During the following growth process, lateral overgrowth will proceed from the Al{sub 0.45}Ga{sub 0.55}N islands on the openings towards the regions covered by SiN{sub x}, relaxing the compressive strain and bending the dislocations at the same time.« less

Quaternary rare-earth sulfides RE{sub 3}M{sub 0.5}GeS{sub 7} (RE=La–Nd, Sm; M=Co, Ni) and Y{sub 3}Pd{sub 0.5}SiS{sub 7}

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

Iyer, Abishek K.; Yin, Wenlong; Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900

The two metal-deficient series of quaternary Ge-containing sulfides RE{sub 3}M{sub 0.5}GeS{sub 7} (RE = La–Nd, Sm; M = Co, Ni), as well as the related Si-containing sulfide Y{sub 3}Pd{sub 0.5}SiS{sub 7}, were prepared by reactions of the elements at 1050 °C. Single-crystal X-ray diffraction analysis performed on all compounds confirmed noncentrosymmetric hexagonal structures (space group P6{sub 3}, Z =2) with cell parameters in the ranges of a =10.0–10.3 Å and c =5.7–5.8 Å for RE{sub 3}Co{sub 0.5}GeS{sub 7} and RE{sub 3}Ni{sub 0.5}GeS{sub 7}, or a =9.7891(3) Å and c =5.6840(4) Å for Y{sub 3}Pd{sub 0.5}SiS{sub 7}. They are classified asmore » La{sub 3}Mn{sub 0.5}SiS{sub 7}-type structures, with M atoms centred within octahedra (in contrast to La{sub 3}CuSiS{sub 7}-type structures in which M atoms occupy trigonal planar sites) and Ge atoms centred within tetrahedra, both types of polyhedra being arranged in one-dimensional stacks aligned along the c-direction. Charge balance requirements dictate half-occupancy of the M sites. However, bond valence sum arguments indicated that the M atoms are somewhat underbonded within these octahedral sites, so that there is evidence that in some compounds, they can also enter the trigonal planar site at low occupancy (~5%). Magnetic measurements on RE{sub 3}Co{sub 0.5}GeS{sub 7} (RE = Ce, Pr, Sm) revealed paramagnetic behaviour for the Ce and Pr members and apparent antiferromagnetic ordering (T{sub N} =14 K) for the Sm member; fitting to the Curie-Weiss law gave effective magnetic moments consistent with the presence of RE{sup 3+} and Co{sup 2+} species. Band structure calculations on ordered models of La{sub 3}M{sub 0.5}GeS{sub 7} (M = Co, Ni) showed that the Fermi level cuts through M 3d states in the DOS curve and supported the presence of strong M–S and Ge–S bonding interactions. - Graphical abstract: RE{sub 3}M{sub 0.5}GeS{sub 7} (M = Co, Ni) and Y{sub 3}Pd{sub 0.5}SiS{sub 7} contain M atoms partially

Potential clinical value of PET/CT in predicting occult nodal metastasis in T1-T2N0M0 lung cancer patients staged by PET/CT

PubMed Central

Zhou, Xiang; Chen, Ruohua; Huang, Gang; Liu, Jianjun

2017-01-01

We assessed the clinical value of 2-fluoro-2-deoxyglucose (18F-FDG) PET/CT imaging for predicting occult nodal metastasis in non-small cell lung cancer (NSCLC) patients. This retrospective study included 54 patients with T1-2N0M0 NSCLC who had undergone 18F-FDG PET/CT before surgery. Occult nodal metastasis was detected in 25.9% (14/54) of the patients. Immunohistochemical analysis revealed that increased glucose transporter 1 expression was associated with occult nodal metastasis, but hexokinase 2 expression was not. Compared to the negative nodal metastasis group, the positive nodal metastasis group was associated with increased maximum standardized uptake value (SUVmax) and tumor size. Multivariate analysis indicated that SUVmax and tumor size were associated with nodal metastasis. Nodal metastasis could be predicted with a sensitivity of 92.9% and a specificity of 55.0% when the SUVmax cutoff was 4.35. When patients were divided into low-risk (tumor size ≤ 2.5 cm and SUVmax ≤ 4.35), moderate-risk (tumor size ≤ 2.5 cm and SUVmax > 4.35 or tumor size > 2.5 cm and SUVmax ≤ 4.35) and high-risk (tumor size > 2.5 cm and SUVmax > 4.35) groups, the lymph node metastasis rates were 4.3%, 22.7%, and 88.9%, respectively. These results indicate that the combination of SUVmax and tumor size has potential clinical value for predicting occult nodal metastasis in NSCLC patients. PMID:29137276

Computer Assisted Medical Diagnosis (CAMD) System Version 1.0 Technical Manual.

DTIC Science & Technology

1992-10-01

Asaasasa S " "ft Mo Q0r "Ma.. @ ffM ’ 0e= 1aw- 0ý K. O - ^0e’O.t-,ý 4V .4 0;P S&. co *;:c Olt 0-oZo6.06-c v- f ’*-IA S0 . N Ml t* Q.0. L . ii a ,I...M& N.-2 1NNNNa N1ý*m N NN NNNNNN NN-NNNNNNN W.9 co 2 ;:N 2 .0 al .0-w -lI -, a? S -J w a a ( ( acca (a *. (a m. a a *.mo i-W - U - - - - U - 4--’- a-W

Native defect-assisted enhanced response to CH4 near room temperature by Al0.07Ga0.93N nanowires.

PubMed

Parida, Santanu; Das, A; Prasad, Arun K; Ghatak, Jay; Dhara, Sandip

2018-06-26

Gas sensors at low operating temperature with high sensitivity require group III nitrides owing to their high chemical and thermal stabilities. For the first time, Al0.07Ga0.93N nanowires (NWs) have been utilized in CH4 sensing, and it has been demonstrated that they exhibit an improved response compared to GaN NWs at the low operating temperature of 50 °C. Al0.07Ga0.93N NWs have been synthesized via the ion beam mixing process using inert gas ion irradiation on the bilayer of Al/GaN NWs. The sensing mechanism is explained with the help of native defects present in the system. The number of shallow acceptors created by Ga vacancies (VGa) is found to be higher in Al0.07Ga0.93N NWs than in as-grown GaN NWs. The role of the O antisite defect (ON) for the formation of shallow VGa is inferred from photoluminescence spectroscopic analysis. These native defects strongly influence the gas sensing behaviour, which results in enhanced and low-temperature CH4 sensing.

p53 predictive value for pT1-2 N0 disease at radical cystectomy.

PubMed

Shariat, Shahrokh F; Lotan, Yair; Karakiewicz, Pierre I; Ashfaq, Raheela; Isbarn, Hendrik; Fradet, Yves; Bastian, Patrick J; Nielsen, Matthew E; Capitanio, Umberto; Jeldres, Claudio; Montorsi, Francesco; Müller, Stefan C; Karam, Jose A; Heukamp, Lukas C; Netto, George; Lerner, Seth P; Sagalowsky, Arthur I; Cote, Richard J

2009-09-01

Approximately 15% to 30% of patients with pT1-2N0M0 urothelial carcinoma of the bladder experience disease progression despite radical cystectomy with curative intent. We determined whether p53 expression would improve the prediction of disease progression after radical cystectomy for pT1-2N0M0 UCB. In a multi-institutional retrospective cohort we identified 324 patients with pT1-2N0M0 urothelial carcinoma of the bladder who underwent radical cystectomy. Analysis focused on a testing cohort of 272 patients and an external validation of 52. Competing risks regression models were used to test the association of variables with cancer specific mortality after accounting for nonbladder cancer caused mortality. In the testing cohort 91 patients (33.5%) had altered p53 expression (p53alt). On multivariate competing risks regression analysis altered p53 achieved independent status for predicting disease recurrence and cancer specific mortality (each p <0.001). Adding p53 increased the accuracy of multivariate competing risks regression models predicting recurrence and cancer specific mortality by 5.7% (62.0% vs 67.7%) and 5.4% (61.6% vs 67.0%), respectively. Alterations in p53 represent a highly promising marker of disease recurrence and cancer specific mortality after radical cystectomy for urothelial carcinoma of the bladder. Analysis confirmed previous findings and showed that considering p53 can result in substantial accuracy gains relative to the use of standard predictors. The value and the level of the current evidence clearly exceed previous proof of the independent predictor status of p53 for predicting recurrence and cancer specific mortality.

A screen-printed Ce 0.8Sm 0.2O 1.9 film solid oxide fuel cell with a Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ cathode

NASA Astrophysics Data System (ADS)

Zhang, Yaohui; Huang, Xiqiang; Lu, Zhe; Liu, Zhiguo; Ge, Xiaodong; Xu, Jiahuan; Xin, Xianshuang; Sha, Xueqing; Su, Wenhui

Screen-printing technology was developed to fabricate Ce 0.8Sm 0.2O 1.9 (SDC) electrolyte films onto porous NiO-SDC green anode substrates. After sintering at 1400 °C for 4 h, a gas-tight SDC film with a thickness of 12 μm was obtained. A novel cathode material of Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ was subsequently applied onto the sintered SDC electrolyte film also by screen-printing and sintered at 970 °C for 3 h to get a single cell. A fuel cell of Ni-SDC/SDC (12 μm)/Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ provides the maximum power densities of 1280, 1080, 670, 370, 180 and 73 mW cm -2 at 650, 600, 555, 505, 455 and 405 °C, respectively, using hydrogen as fuel and stationary air as oxidant. When dry methane was used as fuel, the maximum power densities are 876, 568, 346 and 114 mW cm -2 at 650, 600, 555 and 505 °C, respectively. The present fuel cell shows excellent performance at lowered temperatures.

VizieR Online Data Catalog: Stellar models. 0.85<M<6, Z=0.0001-0.014 (Charbonnel+, 2017)

NASA Astrophysics Data System (ADS)

Charbonnel, C.; Decressin, T.; Lagarde, N.; Gallet, F.; Palacios, A.; Auriere, M.; Konstantinova-Antova, R.; Mathis, S.; Anderson, R. I.; Dintrans, B.

2018-02-01

Grid of stellar models and convective turnover timescale for four metallicities (Z= 0.0001, 0.002, 0.004, and 0.014) in the mass range from 0.85 to 6.0Mȯ. The models are computed either with standard prescriptions or including both thermohaline convection and rotation-induced mixing. For the whole grid, we provide the usual stellar parameters (luminosity, effective temperature, lifetimes, ...), together with the turnover timescale estimated a different heights in the convective envelope and their corresponding Rossby number. (4 data files).

Research of mesa type extended wavelength 64x64 In0.83Ga0.17As detector

NASA Astrophysics Data System (ADS)

Deng, Shuangyan; Li, Ping; Li, Tao; Li, Xue; Shao, Xiumei; Tang, Hengjing; Gong, Haimei

2015-10-01

InxGa1-xAs ternary compound is suitable for detection in the shortwave infrared (1-3μm) band. The alloy In0.53Ga0.47As is lattice-matched to InP substrate and has a wavelength response between 0.9μm to 1.7μm at room temperature. The increase of indium composition can extend the wavelength response to longer infrared wave. With the Indium content 0.83, the cutoff wavelength can be extended to 2.6μm. In this paper, we reported the performance of 64x64 pixels mesa-type back-illuminated extended wavelength InGaAs detector arrays. The mesa type detectors were fabricated by ICP etching, side-wall and surface passivation by ICPCVD (inductively coupled plasma chemical vapor deposition) based on the MBE-grown p-i-n In0.83Al0.17As/In0.83Ga0.17As/InxAl1-xAs/InP epitaxial materials. The I-V characteristics and electro-optical performances of these detectors at different temperatures were measured, and the properties such as dark current, response spectra, responsivity, detectivity were analyzed. The results indicate that the dark current of In0.83Ga0.17As photodiodes decreases with decreasing temperature, varying from 4×10-4A/cm2 at 290K to 1.7×10-8A/cm2 at 180K. The spectral response showed slightly blue shift while the detectors were cooling down, and the cut-off wavelength is 2.57μm at room temperature and 2.43μm at 200K, respectively. The dark current density is 115nA/cm2 at 200K and -10mV bias voltage. The peak detectivity is 6.08E11cmHz1/2W-1.

Predictive criteria for prostate cancer detection in men with serum PSA concentration of 2.0 to 4.0 ng/mL.

PubMed

Kravchick, Sergey; Peled, Ronit; Dorfman, Dov; Agulansky, Leonid; Ben-Dor, David; Cytron, Shmuel

2005-09-01

To assess the usefulness of measuring testosterone, free testosterone, and the free/total (f/t) prostate-specific antigen (PSA) ratio with the intention of reducing the number of unnecessary biopsies in the patients with PSA values between 2.0 and 4.0 ng/mL. Cancer detection is not rare among patients with PSA values between 2.0 and 4.0 ng/mL. A total of 171 men with serum PSA levels of 2.0 to 4.0 ng/mL were enrolled in this study. The f/t PSA ratio and total and free testosterone levels were quantified. All patients underwent transrectal ultrasound-guided biopsy. The cancer detection rate, clinical and pathologic features of the cancers detected, and the probability of cancer detection in relation to the f/t PSA ratio and total and free testosterone levels were estimated. Two-step statistical analysis was used for descriptive purposes and in the detection of cancer predictors. Statistical significance was set at P < or = 0.05. The mean patient age was 63.3 years. Cancer was detected in 39 (22.8%) of the 171 patients. Only 15.4% of our patients had insignificant cancer. The f/t PSA ratio and total and free testosterone levels were significantly lower in the patients with prostate cancer (19.3%, 13.68 nmol/L, and 28.4 pmol/L, respectively; P < 0.001). The f/t PSA ratio and free testosterone were the strongest predictors of cancer detection (P < 0.001). The results of our study have shown that an important number of cancers could be detected in the PSA range of 2.0 to 4.0 ng/mL. The great majority of cancers detected have the features of medically significant tumors. The combination of the f/t PSA ratio and free testosterone measurements may reveal those patients who require biopsy.

Constraints on Omega_0 and cluster evolution using the ROSAT log N-log S relation

NASA Astrophysics Data System (ADS)

Mathiesen, B.; Evrard, A. E.

1998-04-01

We examine the likelihoods of different cosmological models and cluster evolutionary histories by comparing semi-analytical predictions of X-ray cluster number counts with observational data from the ROSAT satellite. We model cluster abundance as a function of mass and redshift using a Press-Schechter distribution, and assume that the temperature T(M,z) and bolometric luminosity L_X(M,z) scale as power laws in mass and epoch, in order to construct expected counts as a function of X-ray flux. The L_X-M scaling is fixed using the local luminosity function, while the degree of evolution in the X-ray luminosity with redshift L_X~(1+z)^s is left open, with s an interesting free parameter which we investigate. We examine open and flat cosmologies with initial, scale-free fluctuation spectra having indices n=0, -1 and -2. An independent constraint arising from the slope of the luminosity-temperature relation strongly favours the n=-2 spectrum. The expected counts demonstrate a strong dependence on Omega_0 and s, with lesser dependence on lambda_0 and n. Comparison with the observed counts reveals a `ridge' of acceptable models in the Omega_0-s plane, roughly following the relation s~6Omega_0 and spanning low-density models with a small degree of evolution to Omega=1 models with strong evolution. Models with moderate evolution are revealed to have a strong lower limit of Omega_0>~0.3, and low-evolution models imply that Omega_0<1 at a very high confidence level. We suggest observational tests for breaking the degeneracy along this ridge, and discuss implications for evolutionary histories of the intracluster medium.

Study of 0.1Ni0.8Zn0.2Fe2O4-0.9Pb1-3x/2LaxZr0.65Ti0.35O3 magnetoelectric composites

NASA Astrophysics Data System (ADS)

Rani, Rekha; Juneja, J. K.; Singh, Sangeeta; Raina, K. K.; Prakash, Chandra

2013-01-01

Magnetoelectric composites of nickel zinc ferrite (NZF) and La substituted lead zirconate titanate (PLZT) having representative formula 0.1Ni0.8Zn0.2Fe2O4-0.9Pb1-3x/2LaxZr0.65Ti0.35O3 (x=0, 0.01, 0.02 and 0.03) were synthesized by a conventional solid state route. X-ray diffraction analysis was carried out to confirm the coexistence of individual phases. Scanning electron microscope micrographs were taken for microstructural study of the samples. Dielectric properties were studied as a function of temperature and frequency. To study ferroelectric and magnetic ordering in composite samples, P-E and M-H hysteresis loops were recorded respectively. M-H hysteresis loops were taken for electrically poled and unpoled samples to confirm magnetoelectric coupling between the two phases (NZF and PLZT). La substitution results in significant improvement in dielectric, ferroelectric and piezoelectric properties of composite samples.

Clinical outcomes using carbon-ion radiotherapy and dose-volume histogram comparison between carbon-ion radiotherapy and photon therapy for T2b-4N0M0 non-small cell lung cancer-A pilot study.

PubMed

Shirai, Katsuyuki; Kawashima, Motohiro; Saitoh, Jun-Ichi; Abe, Takanori; Fukata, Kyohei; Shigeta, Yuka; Irie, Daisuke; Shiba, Shintaro; Okano, Naoko; Ohno, Tatsuya; Nakano, Takashi

2017-01-01

The safety and efficacy of carbon-ion radiotherapy for advanced non-small cell lung cancer have not been established. We evaluated the clinical outcomes and dose-volume histogram parameters of carbon-ion radiotherapy compared with photon therapy in T2b-4N0M0 non-small cell lung cancer. Twenty-three patients were treated with carbon-ion radiotherapy between May 2011 and December 2015. Seven, 14, and 2 patients had T2b, T3, and T4, respectively. The median age was 78 (range, 53-91) years, with 22 male patients. There were 12 adenocarcinomas, 8 squamous cell carcinomas, 1 non-small cell lung carcinoma, and 2 clinically diagnosed lung cancers. Eleven patients were operable, and 12 patients were inoperable. Most patients (91%) were treated with carbon-ion radiotherapy of 60.0 Gy relative biological effectiveness (RBE) in 4 fractions or 64.0 Gy (RBE) in 16 fractions. Local control and overall survival rates were calculated. Dose-volume histogram parameters of normal lung and tumor coverages were compared between carbon-ion radiotherapy and photon therapies, including three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT). The median follow-up of surviving patients was 25 months. Three patients experienced local recurrence, and the 2-year local control rate was 81%. During follow-up, 5 patients died of lung cancer, and 1 died of intercurrent disease. The 2-year overall survival rate was 70%. Operable patients had a better overall survival rate compared with inoperable patients (100% vs. 43%; P = 0.04). There was no grade ≥2 radiation pneumonitis. In dose-volume histogram analysis, carbon-ion radiotherapy had a significantly lower dose to normal lung and greater tumor coverage compared with photon therapies. Carbon-ion radiotherapy was effectively and safely performed for T2b-4N0M0 non-small cell lung cancer, and the dose distribution was superior compared with those for photon therapies. A Japanese multi-institutional study is

Training Extract AFSC 791X0 Public Affairs.

DTIC Science & Technology

1985-09-01

8217 C I 6 8o9 a Is- LI I I ffm cc I C.~ 11 N * 0- Q * .j I .0 L’ ) t.. Cn IC. C~ OU~ *IC - ~ ONcc N.U- 1 0r N a- I A u z a I . A .. I: n] -j 1.’ I I a... Acca r : 𔃺 0 j4 &. a a 40’ 8. x . 09 a n u a i m W Z 15LW4 4 Sn. z 41 0 C. IS L" W. Sn) WL Sn J 0 V. w i Sn - &A ’~S CC 0 Ct 0: Sn w L. -4 04 0 S 4.0- 0

Nano-domain states of strontium ferrites SrFe{sub 1−y}M{sub y}O{sub 2.5+x} (M=V, Mo; y≤0.1; x≤0.2)

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

Ancharova, Uliana V., E-mail: ancharova@gmail.com; Cherepanova, Svetlana V., E-mail: svch@catalysis.ru; Novosibirsk State University, Pirogova st., 2, Novosibirsk 630090

Series of the oxygen-deficient strontium ferrites SrFe{sub 1−y}M{sub y}O{sub 2.5+x} (M=V, Mo, y<0.1; x<0.2) substituted with high-charged cations have been investigated by HRTEM and synchrotron radiation XRD. For artificial lowering of x, all the compounds were treated and quenched in vacuum from 950 °C, which led to the formation of the vacancy-ordered brownmillerite phase at local order. Depending on y, the substituted strontium ferrites have three differently disordered nano-domain states. At y≤0.03 there are twinned lamellar 1D nano-domain structures. At 0.04≤y≤0.05 and 0.06≤y≤0.08 the intergrown 3D nano-domain structures with two different types of disorder are formed. The higher the y,more » the lower the domain size. Disordering phenomena of the 3D nano-domain states were examined with local structure simulations followed by the Debye calculation of XRD patterns. - Graphical abstract: Evolution of nano-domain structure with an increase in the substitution degree y in strontium ferrites SrFe{sub 1−y}M{sub y}O{sub 2.5+x} (M=V, Mo; y≤0.1; x≤0.2): an increase in y decreases the average size of domains and increases the degree of disorder, thus producing the lamellar (1D) or 3D nano-domains. - Highlights: • Two major nanodomain states were found for SrFe{sub 1−y}M{sub y}O{sub 2.5+x} (M=V, Mo, y<0.1; x<0.2). • Both contain vacancy-ordered orthorhombic domains intergrown with cubic matrix. • First (y≤0.03) shows orthorhombic and second (0.04≤y≤0.08) – cubic XRD patterns. • First contains 1D twinned lamellar domains with low-angle boundaries and deformations. • Second contains intergrown isotropic in 3D domains perpendicular oriented in matrix.« less

Definitive hypofractionated radiotherapy for early glottic carcinoma: experience of 55Gy in 20 fractions.

PubMed

Ermiş, Ekin; Teo, Mark; Dyker, Karen E; Fosker, Chris; Sen, Mehmet; Prestwich, Robin Jd

2015-09-23

A wide variety of fractionation schedules have been employed for the treatment of early glottic cancer. The aim is to report our 10-year experience of using hypofractionated radiotherapy with 55Gy in 20 fractions at 2.75Gy per fraction. Patients treated between 2004 and 2013 with definitive radiotherapy to a dose of 55Gy in 20 fractions over 4 weeks for T1/2 N0 squamous cell carcinoma of the glottis were retrospectively identified. Patients with prior therapeutic minor surgery (eg. laser stripping, cordotomy) were included. The probabilities of local control, ultimate local control (including salvage surgery), regional control, cause specific survival (CSS) and overall survival (OS) were calculated. One hundred thirty-two patients were identified. Median age was 65 years (range 33-89). Median follow up was 72 months (range 7-124). 50 (38 %), 18 (14 %) and 64 (48 %) of patients had T1a, T1b and T2 disease respectively. Five year local control and ultimate local control rates were: overall - 85.6 % and 97.3 % respectively, T1a - 91.8 % and 100 %, T1b - 81.6 and 93.8 %, and T2 - 80.9 % and 95.8 %. Five year regional control, CSS and OS rates were 95.4 %, 95.7 % and 78.8 % respectively. There were no significant associations of covariates (e.g. T-stage, extent of laryngeal extension, histological grade) with local control on univariate analysis. Only increasing age and transglottic extension in T2 disease were significantly associated with overall survival (both p <0.01). Second primary cancers developed in 17 % of patients. 13 (9.8 %) of patients required enteral tube feeding support during radiotherapy; no patients required long term enteral nutrition. One patient required a tracheostomy due to a non-functioning larynx on long term follow up. Hypofractionated radiation therapy with a dose of 55Gy in 20 fractions for early stage glottic cancer provides high rates of local control with acceptable toxicity.

Thermal and magnetic characterisation of (Co0.402Fe0.201Ni0.067B0.227Si0.053Nb0.05)100-xCux bulk metallic glasses

NASA Astrophysics Data System (ADS)

Sarlar, Kagan; Kucuk, Ilker

2017-03-01

In this work, Co-based (Co0.402Fe0.201Ni0.067B0.227Si0.053Nb0.05)100-xCux bulk glassy alloys (BMG) with 2 mm diameters were formed by suction-casting method and effect of Cu in this system's thermal stability, glass forming ability and magnetic properties were also investigated. The curves of thermal analysis, obtained using differential scanning calorimetry, show that (Co0.402Fe0.201Ni0.067B0.227Si0.053Nb0.05)100-xCux (x = 0-2) has supercooled liquid region (ΔTx) of about 45 K, and reduced glass transition temperature (Tg/Tl) lies in the range from 0.663 to 0.678. The saturation magnetisation (Js) and coercivity (Hc) for as-cast BMG were in the range of 0.46 T-0.65 T and 13 A/m, respectively.

Structural and magnetic properties of Ni0.8M0.2Fe2O4 (M = Cu, Co) nano-crystalline ferrites

NASA Astrophysics Data System (ADS)

Vijaya Babu, K.; Satyanarayana, G.; Sailaja, B.; Santosh Kumar, G. V.; Jalaiah, K.; Ravi, M.

2018-06-01

Nano-crystalline nickel ferrites are interesting materials due to their large physical and magnetic properties. In the present work, two kinds of spinel ferrites Ni0.8M0.2Fe2O4 (M = Cu, Co) are synthesized by using sol-gel auto-combustion method and the results are compared with NiFe2O4. The structural properties of synthesized ferrites are determined by using X-ray powder diffraction; scanning electron microscope and Fourier transform infrared spectroscopy. The cation distribution obtained from X-ray diffraction show that cobalt/copper occupies only tetrahedral site in spinel lattice. The lattice constant increases with the substitution of cobalt/copper. The structural parameters like bond lengths, tetrahedral and octahedral edges have been varied with the substitution. The microstructural study is carried out by using SEM technique and the average grain size is increased with nickel ferrite. The initial permeability (μi) is improving with the substitution. The observed g-value from ESR is approximately equal to standard value.

Shadoo/PrP (Sprn0/0/Prnp0/0) double knockout mice

PubMed Central

Daude, Nathalie; Westaway, David

2012-01-01

Shadoo (Sho) is a brain glycoprotein with similarities to the unstructured region of PrPC. Frameshift alleles of the Sho gene, Sprn, are reported in variant Creutzfeldt-Jakob disease (vCJD) patients while Sprn mRNA knockdown in PrP-null (Prnp0/0) embryos produces lethality, advancing Sho as the hypothetical PrP-like “pi” protein. Also, Sho levels are reduced as misfolded PrP accumulates during prion infections. To penetrate these issues we created Sprn null alleles (Daude et al., Proc. Natl. Acad. Sci USA 2012; 109(23): 9035–40). Results from the challenge of Sprn null and TgSprn transgenic mice with rodent-adapted prions coalesce to define downregulation of Sho as a “tracer” for the formation of misfolded PrP. However, classical BSE and rodent-adapted BSE isolates may behave differently, as they do for other facets of the pathogenic process, and this intriguing variation warrants closer scrutiny. With regards to physiological function, double knockout mice (Sprn0/0/Prnp0/0) mice survived to over 600 d of age. This suggests that Sho is not pi, or, given the accumulating data for many activities for PrPC, that the pi hypothesis invoking a discrete signaling pathway to maintain neuronal viability is no longer tenable. PMID:22929230

Quantum-confined Stark effect at 1.3 μm in Ge/Si(0.35)Ge(0.65) quantum-well structure.

PubMed

Rouifed, Mohamed Said; Chaisakul, Papichaya; Marris-Morini, Delphine; Frigerio, Jacopo; Isella, Giovanni; Chrastina, Daniel; Edmond, Samson; Le Roux, Xavier; Coudevylle, Jean-René; Vivien, Laurent

2012-10-01

Room-temperature quantum-confined Stark effect in a Ge/SiGe quantum-well structure is reported at the wavelength of 1.3 μm. The operating wavelength is tuned by the use of strain engineering. Low-energy plasma-enhanced chemical vapor deposition is used to grow 20 periods of strain-compensated quantum wells (8 nm Ge well and 12 nm Si(0.35)Ge(0.65) barrier) on Si(0.21)Ge(0.79) virtual substrate. The fraction of light absorbed per well allows for a strong modulation around 1.3 μm. The half-width at half-maximum of the excitonic peak of only 12 meV allows for a discussion on physical mechanisms limiting the performances of such devices.

Structural and dielectric properties of Al x Zn1- x O ( x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10) nanoparticles

NASA Astrophysics Data System (ADS)

Sharma, Neha; Kumar, Sanjay; Sharma, Varun

2018-05-01

The chemical precipitation method is followed for the synthesis of Al-doped ZnO nanoparticles (NPs) with varying doping concentrations (0, 0.02, 0.04, 0.06, 0.08, and 0.10 M). A single hexagonal crystalline phase of wurtzite structure has been confirmed for all the samples by X-ray diffraction. Crystalline size and microstrain of the un-doped and doped ZnO (NPs) is determined by the Williamson-Hall (W-H) analysis. The optical properties like band gap and Urbach energy are found out by the UV-visible spectroscopy. The functional bonds are detailed by Fourier transmission infrared spectroscopy. The dielectric properties have been shown by doped sample due to hopping mechanisms as compared to the undoped. The loss factor (tan δ) follows an inverse direction as correspond to frequency due to the presence of dielectric dispersion.

Highly active La0.4Sr0.6Co0.8Fe0.2O3-δ nanocatalyst for oxygen reduction in intermediate temperature-solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Chanquía, Corina M.; Mogni, Liliana; Troiani, Horacio E.; Caneiro, Alberto

2014-12-01

Pure-phase La0.4Sr0.6Co0.8Fe0.2O3-δ (LSCF) nanocrystallites were successfully synthesized by the combustion method, by employing glycine as fuel and complexing agent, and ammonium nitrate as combustion trigger. The morphological and structural characterization of the LSCF nanopowders was performed by using X-ray diffraction, N2 physisorption and electron microscopy. The LSCF nanopowder consists of interconnected nanocrystallites (∼45 nm) forming a sponge-like structure with meso and macropores, being its specific surface area around 10 m2 g-1. Crystalline structural analyses show that the LSCF nanopowder presents cubic symmetry in the Pm-3m space group. By employing the spin coating technique and different thermal treatments, symmetrical cells with different electrode crystallite size (45 and 685 nm) were built, by using La0.8Sr0.2Ga0.8Mg0.2O3-δ as electrolyte. Electrochemical impedance spectroscopy measurements were performed varying temperature and pO2. The area specific resistance of the nanostructured sample (45 nm) decreases by two orders of magnitude with respect to the submicrostructured sample (685 nm), reaching values as low as 0.8 Ω cm2 at 450 °C. This improvement is attributed to the cathode morphology optimization in the nanoscale, i.e., enlargement of the exposed surface area and shortening of the oxygen diffusion paths, which reduce the polarization resistance associated to the surface exchange and O-ion bulk diffusion process.

Hydrogen passivation and multiple hydrogen-Hg vacancy complex impurities (nH-VHg, n = 1,2,3,4) in Hg0.75Cd0.25Te

NASA Astrophysics Data System (ADS)

Xue, L.; Tang, D. H.; Qu, X. D.; Sun, L. Z.; Lu, Wei; Zhong, J. X.

2011-09-01

Using first-principles method within the framework of the density functional theory, we study the formation energies and the binding energies of multiple hydrogen-mercury vacancy complex impurities (nH-VHg, n = 1,2,3,4) in Hg0.75Cd0.25Te. We find that, when mercury vacancies exist in Hg0.75Cd0.25Te, the formation of the complex impurity between H and VHg (1H-VHg) is easy and its binding energy is up to 0.56 eV. In this case, the deep acceptor level of mercury vacancy is passivated. As the hydrogen concentration increases, we find that the complex impurity between VHg and two hydrogen atoms (2H-VHg) is more stable than 1H-VHg. This complex passivates both the two acceptor levels introduced by mercury vacancy and neutralizes the p-type dopant characteristics of VHg in Hg0.75Cd0.25Te. Moreover, we find that the complex impurities formed by one VHg and three or four H atoms (3H-VHg, 4H-VHg) are still stable in Hg0.75Cd0.25Te, changing the VHg doped p-type Hg0.75Cd0.25Te to n-type material.

Remarkable photocurrent in heterojunctions of n-La0.9Hf0.1MnO3/i-SrTiO3/p-Si at room temperature

NASA Astrophysics Data System (ADS)

Liu, Xiangbo; Jin, Libin; Lu, Huibin; Gao, Ju

2016-04-01

Controllable manipulation for electrical transport in manganite-based heterojunctions have been desired and studied all the time due to their promising applications in electronic and spintronic devices. We report heterojunctions composed by n-type La0.9Hf0.1MnO3 and p-type Si with a SrTiO3 interlayer. The junctions reveal the formation of n-i-p junction in a wide temperature range of 20-300 K. Under illumination of 630 nm light, remarkable photocurrent has been observed. The photosensitivity (IS), defined as the ratio of photocurrent to dark current, reaches over 1200% under -3 V bias and illumination of red light with 10 mW cm-2 at room temperature. Even light power density is as low as 0.2 mW cm-2, IS is still over 200% under -1.5 V bias. The injection of photo-carriers could be responsible for the observed phenomenon. Such manipulative features by light illumination and bias should be of great potential for functional light sensors.

Magnetically driven negative thermal expansion in antiperovskite Ga1-xMnxN0.8Mn3 (0.1 ≤ x ≤ 0.3)

NASA Astrophysics Data System (ADS)

Guo, X. G.; Lin, J. C.; Tong, P.; Wang, M.; Wu, Y.; Yang, C.; Song, B.; Lin, S.; Song, W. H.; Sun, Y. P.

2015-11-01

Negative thermal expansion (NTE) was investigated for Ga1-xMnxN0.8Mn3 (0.1 ≤ x ≤ 0.3). As x increases, the temperature range where lattice contracts upon heating becomes broad and shifts to lower temperatures. The coefficient of linear thermal expansion beyond -40 ppm/K with a temperature interval of ˜50 K was obtained around room temperature in x = 0.2 and 0.25. Local lattice distortion which was thought to be intimately related to NTE is invisible in the X-ray pair distribution function of x = 0.3. Furthermore, a zero-field-cooling exchange bias was observed as a result of competing ferromagnetic (FM) and antiferromagnetic (AFM) orders. The concomitant FM order serves as an impediment to the growth of the AFM order, and thus broadens the temperature range of NTE. Our result suggests that NTE can be achieved in antiperovskite manganese nitrides by manipulating the magnetic orders without distorting the local structure.

Interaction of 1.05 μm and 0.53 μm lasers with gold disks

NASA Astrophysics Data System (ADS)

Shenye, Liu; Yaonan, Ding; Zhijian, Zheng; Daoyuan, Tang

1996-05-01

Gold disks were irradiated with 1.05 μm and 0.53 μm lasers at pulse duration of ˜0.8 ns, intensity ranging from 5×1013 W/cm2 to 4×1015 W/cm2 on the SHEN GUANG I laser facility in China. The experimental results of laser absorption, scattering light, x-ray emission and plasma blow-off are presented in this paper. When the laser irradiated the gold disk obliquely, the angular distribution of scattered lights produced by 0.53 μm lasers disagree with that predicted by the Brillouin scattering theory. The angular distribution is different from that reported previously by the others.

Mono- and bimetallic zwitterionic chromium(0) and tungsten(0) allenyls.

PubMed

Giner, Elena A; Santiago, Alicia; Gómez-Gallego, Mar; Ramírez de Arellano, Carmen; Poulten, Rebecca C; Whittlesey, Michael K; Sierra, Miguel A

2015-06-01

A series of stable chiral (racemic), formally neutral, zwitterionic mono- and bimetallic M(CO)5[C(OEt)═C═CR(NHC)] (M = Cr, W) σ-allenyls are ready available by the addition of N-heterocyclic carbenes (NHCs) to Cr(0) and W(0) alkynyl Fischer carbene complexes. Different classes of NHCs, (e.g., 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, and their six- and seven-membered analogues and 1,3-bis(dimethyl)imidazol-2-ylidene) were employed as nucleophiles in these C-C bond-forming reactions yielding the novel complexes in essentially quantitative yields. A systematic experimental and computational study of the electronic properties of the Cr- and W-allenyls shows that their UV-vis spectra are directly influenced by the structure of the heterocyclic moiety derived from the NHC (ring size, substituents on the N atoms) and by the nature of the metal fragment (Cr/W). The electron-releasing nature of these complexes allows them to participate in electron-transfer reactions in the ground state, leading to a type of charged α,β-unsaturated Fischer carbenes that incorporate an NHC fragment in their structure.

Superconducting phase transitions in mK temperature range in splat-cooled U0.85Pt0.15 alloys

NASA Astrophysics Data System (ADS)

Kim-Ngan, N.-T. H.; Tarnawski, Z.; Chrobak, M.; Sowa, S.; Duda, A.; Paukov, M.; Buturlim, V.; Havela, L.

2018-05-01

We present the temperature and magnetic-field dependence of the electrical resistivity (ρ(T,B)) in the mK temperature range used as a diagnostic tool for the superconductivity of U-Pt alloys prepared by splat-cooling technique. In most of the investigated alloys, a single resistivity drop was observed at the superconducting transition. For splat-cooled U0.85Pt0.15 (U-15 at% Pt) alloys, two drops were revealed around 0.6 K and 1 K tentatively attributed to the superconducting phase transitions of the γ-U phase and α-U phase. The ρ(T,B) characteristics were found to depend on the cooling rate. The superconductivity is characterized by very high upper critical fields, reaching 4.5 T in the 0 K limit.

Increased therapeutic ratio by 18FDG-PET CT planning in patients with clinical CT stage N2-N3M0 non-small-cell lung cancer: a modeling study.

PubMed

van Der Wel, Antoinet; Nijsten, Sebastiaan; Hochstenbag, Monique; Lamers, Rob; Boersma, Liesbeth; Wanders, Rinus; Lutgens, Ludy; Zimny, Michael; Bentzen, Søren M; Wouters, Brad; Lambin, Philippe; De Ruysscher, Dirk

2005-03-01

With this modeling study, we wanted to estimate the potential gain from incorporating fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning in the radiotherapy treatment planning of CT Stage N2-N3M0 non-small-cell lung cancer (NSCLC) patients. Twenty-one consecutive patients with clinical CT Stage N2-N3M0 NSCLC were studied. For each patient, two three-dimensional conformal treatment plans were made: one with a CT-based planning target volume (PTV) and one with a PET-CT-based PTV, both to deliver 60 Gy in 30 fractions. From the dose-volume histograms and dose distributions on each plan, the dosimetric factors predicting esophageal and lung toxicity were analyzed and compared. For each patient, the maximal tolerable prescribed radiation dose for the CT PTV vs. PET-CT PTV was calculated according to the constraints for the lung, esophagus, and spinal cord. From these results, the tumor control probability (TCP) was estimated, assuming a clinical dose-response curve with a median toxic dose of 84.5 Gy and a gamma(50) of 2.0. Dose-response curves were modeled, taking into account geographic misses according to the accuracy of CT and PET in our institutions. The gross tumor volume of the nodes decreased from 13.7 +/- 3.8 cm(3) on the CT scan to 9.9 +/- 4.0 cm(3) on the PET-CT scan (p = 0.011). All dose-volume characteristics for the esophagus and lungs decreased in favor of PET-CT. The esophageal V(45) (the volume of the esophagus receiving 45 Gy) decreased from 45.2% +/- 4.9% to 34.0% +/- 5.8% (p = 0.003), esophageal V(55) (the volume of the esophagus receiving 55 Gy) from 30.6% +/- 3.2% to 21.9% +/- 3.8% (p = 0.004), mean esophageal dose from 29.8 +/- 2.5 Gy to 23.7 +/- 3.1 Gy (p = 0.004), lung V(20) (the volume of the lungs minus the PTV receiving 20 Gy) from 24.9% +/- 2.3% to 22.3% +/- 2.2% (p = 0.012), and mean lung dose from 14.7 +/- 1.3 Gy to 13.6 +/- 1.3 Gy (p = 0.004). For the same toxicity levels of the lung, esophagus, and spinal cord, the dose

Stable Ferroelectric Behavior of Nb-Modified Bi0.5K0.5TiO3-Bi(Mg0.5Ti0.5)O3 Lead-Free Relaxor Ferroelectric Ceramics

NASA Astrophysics Data System (ADS)

Zaman, Arif; Malik, Rizwan Ahmed; Maqbool, Adnan; Hussain, Ali; Ahmed, Tanveer; Song, Tae Kwon; Kim, Won-Jeong; Kim, Myong-Ho

2018-03-01

Crystal structure, dielectric, ferroelectric, piezoelectric, and electric field-induced strain properties of lead-free Nb-modified 0.96Bi0.5K0.5TiO3-0.04Bi(Mg0.5Ti0.5)O3 (BKT-BMT) piezoelectric ceramics were investigated. Crystal structure analysis showed a gradual phase transition from tetragonal to pseudocubic phase with increasing Nb content. The optimal piezoelectric property of small-signal d 33 was enhanced up to ˜ 68 pC/N with a lower coercive field ( E c) of ˜ 22 kV/cm and an improved remnant polarization ( P r) of ˜ 13 μC/cm2 for x = 0.020. A relaxor-like behavior with a frequency-dependent Curie temperature T m was observed, and a high T m around 320°C was obtained in the investigated system. This study suggests that the ferroelectric properties of BKT-BMT was significantly improved by means of Nb substitution. The possible shift of depolarization temperature T d toward high temperature T m may have triggered the spontaneous relaxor to ferroelectric phase transition with long-range ferroelectric order without any traces of a nonergodic relaxor state in contradiction with Bi0.5Na0.5TiO3-based systems. The possible enhancement in ferroelectric and piezoelectric properties near the critical composition x = 0.020 may be attributed to the increased anharmonicity of lattice vibrations which may facilitate the observed phase transition from a low-symmetry tetragonal to a high-symmetry cubic phase with a decrease in the lattice anisotropy of an undoped sample. This highly flexible (at a unit cell level) narrow compositional range triggers the enhancement of d 33 and P r values.

Stellar mass and age determinations . I. Grids of stellar models from Z = 0.006 to 0.04 and M = 0.5 to 3.5 M⊙

NASA Astrophysics Data System (ADS)

Mowlavi, N.; Eggenberger, P.; Meynet, G.; Ekström, S.; Georgy, C.; Maeder, A.; Charbonnel, C.; Eyer, L.

2012-05-01

Aims: We present dense grids of stellar models suitable for comparison with observable quantities measured with great precision, such as those derived from binary systems or planet-hosting stars. Methods: We computed new Geneva models without rotation at metallicities Z = 0.006, 0.01, 0.014, 0.02, 0.03, and 0.04 (i.e. [Fe/H] from -0.33 to +0.54) and with mass in small steps from 0.5 to 3.5 M⊙. Great care was taken in the procedure for interpolating between tracks in order to compute isochrones. Results: Several properties of our grids are presented as a function of stellar mass and metallicity. Those include surface properties in the Hertzsprung-Russell diagram, internal properties including mean stellar density, sizes of the convective cores, and global asteroseismic properties. Conclusions: We checked our interpolation procedure and compared interpolated tracks with computed tracks. The deviations are less than 1% in radius and effective temperatures for most of the cases considered. We also checked that the present isochrones provide nice fits to four couples of observed detached binaries and to the observed sequences of the open clusters NGC 3532 and M 67. Including atomic diffusion in our models with M < 1.1 M⊙ leads to variations in the surface abundances that should be taken into account when comparing with observational data of stars with measured metallicities. For that purpose, iso-Zsurf lines are computed. These can be requested for download from a dedicated web page, together with tracks at masses and metallicities within the limits covered by the grids. The validity of the relations linking Z and [Fe/H] is also re-assessed in light of the surface abundance variations in low-mass stars. Table D.1 for the basic tracks is available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/541/A41, and on our web site http

Growth of congruently melting Ca0.59Sr0.41F2 crystals and study of their properties

NASA Astrophysics Data System (ADS)

Karimov, D. N.; Komar'kova, O. N.; Sorokin, N. I.; Bezhanov, V. A.; Chernov, S. P.; Popov, P. A.; Sobolev, B. P.

2010-05-01

Homogeneous crystals of Ca0.59Sr0.41F2 alloy (sp. gr., Fm bar 3 m, a = 0.56057 nm), corresponding to the point of minimum in the melting curve in the CaF2-SrF2 phase diagram, have been grown by the vertical Bridgman method. The optical, mechanical, electrical, and thermophysical properties of Ca0.59Sr0.41F2 and MF2 crystals ( M = Ca, Sr) have been studied and comparatively analyzed. Ca0.59Sr0.41F2 crystals are transparent in the range of 0.133-11.5 μm, have refractive index n D = 1.436, microhardness H μ = 2.63 ± 0.10 GPa, ion conductivity σ = 5 × 10-5 S/cm at 825 K, and thermal conductivity k = 4.0 W m-1 K-1 at 300 K. It is shown that the optical properties of Ca0.59Sr0.41F2 crystals are intermediate between those of CaF2 and SrF2, whereas their mechanical and electrical characteristics are better than the latter compounds.

Ferroelectric switching in epitaxial PbZr0.2Ti0.8O3/ZnO/GaN heterostructures

NASA Astrophysics Data System (ADS)

Wang, Juan; Salev, Pavel; Grigoriev, Alexei

As a wide-bandgap semiconductor, ZnO has gained substantial interest due to its favorable properties including high electron mobility, strong room-temperature luminescence, etc. The main obstacle of its application is the lack of reproducible and low-resistivity p-type ZnO. P-type doping of ZnO through the interface charge injection, which can be achieved by the polarization switching of ferroelectric films, is a tempting solution. We explored ferroelectric switching behavior of PbZr0.2Ti0.8O3/ZnO/GaN heterostructures epitaxially grown on Sapphire substrates by RF sputtering. The electrical measurements of Pt/PbZr0.2Ti0.8O3/ZnO/GaN ferroelectric-semiconductor capacitors revealed unusual behavior that is a combination of polarization switching and a diode I-V characteristics.

Reversible operation of microtubular solid oxide cells using La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.1O2-δ oxygen electrodes

NASA Astrophysics Data System (ADS)

López-Robledo, M. J.; Laguna-Bercero, M. A.; Larrea, A.; Orera, V. M.

2018-02-01

Yttria stabilized zirconia (YSZ) based microtubular solid oxide fuel cells (mT-SOFCs) using La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and Ce0.9Gd0.1O2-δ (GDC) as the oxygen electrode, along with a porous GDC electrolyte-electrode barrier layer, were fabricated and characterized in both fuel cell (SOFC) and electrolysis (SOEC) operation modes. The cells were anode-supported, the NiO-YSZ microtubular supports being made by Powder Extrusion Moulding (PEM). The cells showed power densities of 695 mW cm-2 at 800 °C and 0.7 V in SOFC mode, and of 845 mA cm-2 at 800 °C and 1.3 V in SOEC mode. AC impedance experiments performed under different potential loads demonstrated the reversibility of the cells. These results showed that these cells, prepared with a method suitable for using on an industrial scale, are highly reproducible and reliable, as well as very competitive as reversible SOFC-SOEC devices operating at intermediate temperatures.

The investigation of Al0.29Ga0.71N/GaN/AlN and AlN/GaN/AlN thin films grown on Si (111) by RF plasma-assisted MBE

NASA Astrophysics Data System (ADS)

Yusoff, Mohd Zaki Mohd; Mahyuddin, Azzafeerah; Hassan, Zainuriah; Hassan, Haslan Abu; Abdullah, Mat Johar

2012-06-01

Recently, gallium nitride (GaN) and its related compounds involving Al and In have attracted much attention because of their potential to be used as high-efficiency UV light emitting devices, and as high frequency and high power electronic devices. Consequently, the growth and physics of GaN-based materials have attracted remarkable scientific attention. In this work, the growth and characterization of epitaxial Al0.29Ga0.71N and AlN layers grown on Si (111) by RF-plasma assisted molecular beam epitaxy (MBE) are described. The Al mole fraction was derived from the HR-XRD symmetric rocking curve (RC) ω/2θ scans of (0002) plane as x = 0.29. For AlN/GaN/AlN sample, the maximum Raman intensity at 521.53 cm-1 is attributed to crystalline silicon. It was found that the allowed Raman optical phonon mode of GaN, the E1 (high) is clearly visible, which is located at 570.74 cm-1. Photoluminscence (PL) spectrums of both samples have shown sharp and intense band edge emission of GaN without the existence of yellow emission band, showing good crystal quality of the samples have been successfully grown on Si substrate.

Study of Cs/NF3 adsorption on GaN (0 0 1) surface

NASA Astrophysics Data System (ADS)

Diao, Yu; Liu, Lei; Xia, Sihao; Kong, Yike

2017-03-01

To investigate the optoelectronics properties of Cs/NF3 adsorption on GaN (0 0 1) photocathode surface, different adsorption models of Cs-only, Cs/O, Cs/NF3 adsorption on GaN clean surface were established, respectively. Atomic structures, work function, adsorption energy, E-Mulliken charge distribution, density of states and optical properties of all these adsorption systems were calculated using first principles. Compared with Cs/O co-adsorption, Cs/NF3 co-adsorption show better stability and more decline of work function, which is more beneficial for photoemission efficiency. Besides, surface band structures of Cs/NF3 co-adsorption system exhibit metal properties, implying good conductivity. Meanwhile, near valence band minimum of Cs/NF3 co-adsorption system, more acceptor levels emerges to form a p-type emission surface, which is conductive to the escape of photoelectrons. In addition, imaginary part of dielectric function curve and absorption curve of Cs/NF3 co-adsorption system both move towards lower energy side. This work can direct the optimization of activation process of NEA GaN photocathode.

Low Resistance, Unannealed ohmic Contacts to n-Type InAs0.66Sb0.34

DTIC Science & Technology

2007-11-08

by solid-source molecular beam epitaxy (MBE). Structures consisted of a semi-insulating GaAs substrate, a 1.0 mm undoped AlSb buffer, and 1.0 mm n...6.1 Å-based HEMTs have been demonstrated recently [1, 2]. New materials such as InxGa1-xSb, InAsySb1-y, and InxAl1-xAsySb1-y, with lattice constants...speed operation [3]. Initial work on HEMTs and InAs heterojunction bipolar transistors (HBTs) has been promising [1, 4–7], but the fabrication of 6.2 Å

Actinide Oxidation State and O/M Ratio in Hypostoichiometric Uranium-Plutonium-Americium U0.750Pu0.246Am0.004O2-x Mixed Oxides.

PubMed

Vauchy, Romain; Belin, Renaud C; Robisson, Anne-Charlotte; Lebreton, Florent; Aufore, Laurence; Scheinost, Andreas C; Martin, Philippe M

2016-03-07

Innovative americium-bearing uranium-plutonium mixed oxides U1-yPuyO2-x are envisioned as nuclear fuel for sodium-cooled fast neutron reactors (SFRs). The oxygen-to-metal (O/M) ratio, directly related to the oxidation state of cations, affects many of the fuel properties. Thus, a thorough knowledge of its variation with the sintering conditions is essential. The aim of this work is to follow the oxidation state of uranium, plutonium, and americium, and so the O/M ratio, in U0.750Pu0.246Am0.004O2-x samples sintered for 4 h at 2023 K in various Ar + 5% H2 + z vpm H2O (z = ∼ 15, ∼ 90, and ∼ 200) gas mixtures. The O/M ratios were determined by gravimetry, XAS, and XRD and evidenced a partial oxidation of the samples at room temperature. Finally, by comparing XANES and EXAFS results to that of a previous study, we demonstrate that the presence of uranium does not influence the interactions between americium and plutonium and that the differences in the O/M ratio between the investigated conditions is controlled by the reduction of plutonium. We also discuss the role of the homogeneity of cation distribution, as determined by EPMA, on the mechanisms involved in the reduction process.

Lateral gradients of phases, residual stress and hardness in a laser heated Ti0.52Al0.48N coating on hard metal

PubMed Central

Bartosik, M.; Daniel, R.; Zhang, Z.; Deluca, M.; Ecker, W.; Stefenelli, M.; Klaus, M.; Genzel, C.; Mitterer, C.; Keckes, J.

2012-01-01

The influence of a local thermal treatment on the properties of Ti–Al–N coatings is not understood. In the present work, a Ti0.52Al0.48N coating on a WC–Co substrate was heated with a diode laser up to 900 °C for 30 s and radially symmetric lateral gradients of phases, residual stress and hardness were characterized ex-situ using position-resolved synchrotron X-ray diffraction, Raman spectroscopy, transmission electron microscopy and nanoindentation. The results reveal (i) a residual stress relaxation at the edge of the irradiated area and (ii) a compressive stress increase of few GPa in the irradiated area center due to the Ti–Al–N decomposition, in particular due to the formation of small wurtzite (w) AlN domains. The coating hardness increased from 35 to 47 GPa towards the center of the heated spot. In the underlying heated substrate, a residual stress change from about − 200 to 500 MPa down to a depth of 6 μm is observed. Complementary, in-situ high-temperature X-ray diffraction analysis of stresses in a homogeneously heated Ti0.52Al0.48N coating on a WC–Co substrate was performed in the range of 25–1003 °C. The in-situ experiment revealed the origin of the observed thermally-activated residual stress oscillation across the laser heated spot. Finally, it is demonstrated that the coupling of laser heating to produce lateral thermal gradients and position-resolved experimental techniques opens the possibility to perform fast screening of structure–property relationships in complex materials. PMID:23471140

Observation of the Decay B_{s}^{0}→K^{0}K[over ¯]^{0}.

PubMed

Pal, B; Schwartz, A J; Abdesselam, A; Adachi, I; Aihara, H; Asner, D M; Aushev, T; Ayad, R; Aziz, T; Babu, V; Badhrees, I; Bahinipati, S; Bakich, A M; Barberio, E; Behera, P; Bhardwaj, V; Bhuyan, B; Biswal, J; Bobrov, A; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chistov, R; Cho, K; Chobanova, V; Choi, Y; Cinabro, D; Dalseno, J; Dash, N; Doležal, Z; Drásal, Z; Drutskoy, A; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Fulsom, B G; Gaur, V; Garmash, A; Gillard, R; Goh, Y M; Goldenzweig, P; Greenwald, D; Grzymkowska, O; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; He, X H; Hou, W-S; Inami, K; Ishikawa, A; Iwasaki, Y; Jacobs, W W; Jaegle, I; Jeon, H B; Joffe, D; Joo, K K; Julius, T; Kang, K H; Kato, E; Kawasaki, T; Kiesling, C; Kim, D Y; Kim, H J; Kim, K T; Kim, M J; Kim, S H; Kinoshita, K; Kodyš, P; Korpar, S; Križan, P; Krokovny, P; Kuhr, T; Kumar, R; Kumita, T; Kuzmin, A; Kwon, Y-J; Lee, I S; Li, C H; Li, H; Li, L; Li Gioi, L; Libby, J; Liventsev, D; Lukin, P; Luo, T; Masuda, M; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Mohanty, G B; Mohanty, S; Moll, A; Moon, H K; Mori, T; Mussa, R; Nakano, E; Nakao, M; Nanut, T; Natkaniec, Z; Nayak, M; Nisar, N K; Nishida, S; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Paul, S; Pedlar, T K; Pesántez, L; Pestotnik, R; Petrič, M; Piilonen, L E; Pulvermacher, C; Rauch, J; Ribežl, E; Ritter, M; Rostomyan, A; Ryu, S; Sahoo, H; Sakai, Y; Sandilya, S; Sanuki, T; Sato, Y; Savinov, V; Schlüter, T; Schneider, O; Schnell, G; Schwanda, C; Seino, Y; Senyo, K; Seon, O; Seong, I S; Shebalin, V; Shibata, T-A; Shiu, J-G; Shwartz, B; Simon, F; Sohn, Y-S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Stypula, J; Sumihama, M; Sumiyoshi, T; Tamponi, U; Teramoto, Y; Trabelsi, K; Uchida, M; Uehara, S; Uglov, T; Uno, S; Urquijo, P; Usov, Y; Van Hulse, C; Vanhoefer, P; Varner, G; Vinokurova, A; Vossen, A; Wagner, M N; Wang, C H; Wang, M-Z; Wang, X L; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yamaoka, J; Yelton, J; Yuan, C Z; Yusa, Y; Zhang, Z P; Zhilich, V; Zhulanov, V; Zupanc, A

2016-04-22

We measure the decay B_{s}^{0}→K^{0}K[over ¯]^{0} using data collected at the ϒ(5S) resonance with the Belle detector at the KEKB e^{+}e^{-} collider. The data sample used corresponds to an integrated luminosity of 121.4  fb^{-1}. We measure a branching fraction B(B_{s}^{0}→K^{0}K[over ¯]^{0})=[19.6_{-5.1}^{+5.8}(stat)±1.0(syst)±2.0(N_{B_{s}^{0}B[over ¯]_{s}^{0}})]×10^{-6} with a significance of 5.1 standard deviations. This measurement constitutes the first observation of this decay.

Ferromagnetic-Antiferromagnetic Coupling by Distortion of Fe/Mn Oxygen Octahedrons in (BiFeO3 )m (La0.7 Sr0.3 MnO3 )n Superlattices.

PubMed

Xiong, Jie; Lei, Tianyu; Chu, Junwei; Yang, Chao; Wei, Jiake; Zhuo, Mujin; Choi, Eun-Mi; Tao, Bowan; Zhang, Wanli; Wang, Yongqiang; Li, Yanrong

2017-05-01

Interface enhanced magnetism attracts much attention due to its potential use in exploring novel structure devices. Nevertheless, the magnetic behavior at interfaces has not been quantitatively determined. In this study, abnormal magnetic moment reduction is observed in La 0.7 Sr 0.3 MnO 3 (LSMO)/BiFeO 3 (BFO) superlattices, which is induced by ferromagnetic (FM)/antiferromagnetic (AFM) coupling in the interface. With reduced repetition of the superlattice's unit cell [(LSMO) n /(BFO) n ] 60/ n (n = 1, 2, 5, 10) on a SrTiO 3 substrate, magnetic moment reduction from 25.5 emu cc -1 ([(LSMO) 10 /(BFO) 10 ] 6 ) to 1.5 emu cc -1 ([(LSMO) 1 /(BFO) 1 ] 60 ) is obtained. Ab initio simulations show that due to the different magnetic domain formation energies, the magnetic moment orientation tends to be paramagnetic in the FM/AFM interface. The work focuses on the magnetic domain formation energy and provides a pathway to construct artificial heterostructures that can be an effective way to tune the magnetic moment orientation and control the magnetization of ultrathin films. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An analysis of lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic for efficient refrigeration and thermal energy harvesting

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

Vats, Gaurav; Vaish, Rahul, E-mail: rahul@iitmandi.ac.in; Bowen, Chris R.

This article demonstrates the colossal energy harvesting capability of a lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic using the Olsen cycle. The maximum harvestable energy density estimated for this system is found to be 1523 J/L (1523 kJ/m{sup 3}) where the results are presented for extreme ambient conditions of 20–160 °C and electric fields of 0.1–4 MV/m. This estimated energy density is 1.7 times higher than the maximum reported to date for the lanthanum-doped lead zirconate titanate (thin film) system. Moreover, this study introduces a generalized and effective solid state refrigeration cycle in contrast to the ferroelectric Ericsonmore » refrigeration cycle. The cycle is based on a temperature induced polarization change on application of an unipolar electric field to ferroelectric ceramics.« less

Structural and rectifying junction properties of self-assembled ZnO nanoparticles in polystyrene diblock copolymers on (1 0 0)Si substrates

NASA Astrophysics Data System (ADS)

Ali, H. A.; Iliadis, A. A.; Martinez-Miranda, L. J.; Lee, U.

2006-06-01

The structural and electronic transport properties of self-assembled ZnO nanoparticles in polystyrene-acrylic acid, [PS] m/[PAA] n, diblock copolymer on p-type (1 0 0)Si substrates are reported for the first time. Four different block repeat unit ratios ( m/ n) of 159/63, 139/17,106/17, and 106/4, were examined in order to correlate the physical parameters (size, density) of the nanoparticles with the copolymer block lengths m and n. We established that the self-assembled ZnO nanoparticle average size increased linearly with minority block length n, while the average density decreased exponentially with majority block length m. Average size varied from 20 nm to 250 nm and average density from 3.5 × 10 7 cm -2 to 1 × 10 10 cm -2, depending on copolymer parameters. X-ray diffraction studies showed the particles to have a wurtzite crystal structure with the (1 0 0) being the dominant orientation. Room temperature current-voltage characteristics measured for an Al/ZnO-nanocomposite/Si structure exhibited rectifying junction properties and indicated the formation of Al/ZnO-nanocomposite Schottky type junction with a barrier height of 0.7 V.

Sucrose-aided combustion synthesis of nanosized LiMn 1.99- yLi yM 0.01O 4 (M = Al 3+, Ni 2+, Cr 3+, Co 3+, y = 0.01 and 0.06) spinels . Characterization and electrochemical behavior at 25 and at 55 °C in rechargeable lithium cells

NASA Astrophysics Data System (ADS)

Amarilla, J. M.; Petrov, K.; Picó, F.; Avdeev, G.; Rojo, J. M.; Rojas, R. M.

Doubly doped LiMn 1.99- yLi yM 0.01O 4 (M = Al 3+, Ni 2+, Cr 3+, Co 3+; y = 0.01 and 0.06) spinels have been synthesized by the sucrose-aided combustion method. Combined TG/DTA and XRD studies have shown that stoichiometric single-phase spinels are formed after annealing of the samples at 700 °C for 1 h. The samples obtained are nanocrystalline materials having a narrow size-distribution and a coherent domain size between 40 and 60 nm, depending on the amount of fuel (sucrose) used in the synthesis. The influence of the Li-excess, the type of M n+-dopant cation and the amount of fuel used in the synthesis on the electrochemical behavior of the spinels in a Li-cell at room and at elevated temperature (55 °C) has been studied. At 25 °C all the spinels synthesized have a good capacity retention after 100 cycles, QRt-100 > 92%. At 55 °C the increase of the Li-excess improves the cycling performances. Rate capability studies show that the spinels retain >90% of their capacity even at 5 C rate. The synergic effect of the Li-excess and the particle size on the electrochemical properties of the spinels as cathode material has been settled. The LiMn 1.93Li 0.06M 0.01O 4, (M = Al 3+, Ni 2+) spinels, with cyclabilities >99.9% by cycle at both 25 and 55 °C, and high rate capabilities, are the ones that show the best electrochemical properties.

Dosimetric comparison of helical tomotherapy, intensity-modulated radiation therapy, volumetric-modulated arc therapy, and 3-dimensional conformal therapy for the treatment of T1N0 glottic cancer

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

Ekici, Kemal, E-mail: drkemal06@hotmail.com; Pepele, Eda K.; Yaprak, Bahaddin

2016-01-01

Various radiotherapy planning methods for T1N0 laryngeal cancer have been proposed to decrease normal tissue toxicity. We compare helical tomotherapy (HT), linac-based intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT), and 3-D conformal radiotherapy (3D-CRT) techniques for T1N0 laryngeal cancer. Overall, 10 patients with T1N0 laryngeal cancer were selected and evaluated. Furthermore, 10 radiotherapy treatment plans have been created for all 10 patients, including HT, IMRT, VMAT, and 3D-CRT. IMRT, VMAT, and HT plans vs 3D-CRT plans consistently provided superior planning target volume (PTV) coverage. Similar target coverage was observed between the 3 IMRT modalities. Compared with 3D-CRT, IMRT, HT,more » and VMAT significantly reduced the mean dose to the carotid arteries. VMAT resulted in the lowest mean dose to the submandibular and thyroid glands. Compared with 3D-CRT, IMRT, HT, and VMAT significantly increased the maximum dose to the spinal cord It was observed that the 3 IMRT modalities studied showed superior target coverage with less variation between each plan in comparison with 3D-CRT. The 3D-CRT plans performed better at the D{sub max} of the spinal cord. Clinical investigation is warranted to determine if these treatment approaches would translate into a reduction in radiation therapy–induced toxicities.« less

PSA Nadir of <0.5 ng/mL Following Brachytherapy for Early-Stage Prostate Adenocarcinoma is Associated With Freedom From Prostate-Specific Antigen Failure

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

Ko, Eric C.; Stone, Nelson N.; Department of Urology, Mount Sinai Medical Center, New York, NY

2012-06-01

Purpose: Because limited information exists regarding whether the rate or magnitude of PSA decline following brachytherapy predicts long-term clinical outcomes, we evaluated whether achieving a prostate-specific antigen (PSA) nadir (nPSA) <0.5 ng/mL following brachytherapy is associated with decreased PSA failure and/or distant metastasis. Methods and Materials: We retrospectively analyzed our database of early-stage prostate adenocarcinoma patients who underwent brachytherapy, excluding those receiving androgen-deprivation therapy and those with <2 years follow-up. Median and mean pretreatment PSA were 6 ng/mL and 7.16 ng/mL, respectively. By clinical stage, 775 were low risk ({<=}T2a), 126 were intermediate risk (T2b), and 20 were high riskmore » (>T2b). By Gleason score, 840 were low risk ({<=}6), 71 were intermediate risk (7), and 10 were high risk (>7). Patients were treated with brachytherapy only (I-125, n = 779, or Pd-103, n = 47), or brachytherapy + external-beam radiation therapy (n = 95). Median follow-up was 6.3 years. We noted whether nPSA <0.5 ng/mL was achieved and the time to achieve this nadir and tested for associations with pretreatment risk factors. We also determined whether this PSA endpoint was associated with decreased PSA failure or distant metastasis. Results: Absence of high-risk factors in clinical stage ({<=}T2b), Gleason score ({<=}7), and pretreatment PSA ({<=}20 ng/mL) was significantly associated with achieving nPSA <0.5 ng/mL. By Kaplan-Meier analysis, patients achieving nPSA <0.5 ng/mL had significantly higher long-term freedom from biochemical failure (FFBF) than nonresponders (5-year FFBF: 95.2 {+-} 0.8% vs. 71.5 {+-} 6.7%; p < 0.0005). Among responders, those who achieved nPSA <0.5 ng/mL in {<=}5 years had higher FFBF than those requiring >5 years (5-year FFBF: 96.7 {+-} 0.7% vs. 80.8 {+-} 4.6%; p < 0.0005). On multivariate analysis, patients who achieved nPSA <0.5 ng/mL in {<=}5 years had significantly higher FFBF than other

PSA nadir of <0.5 ng/mL following brachytherapy for early-stage prostate adenocarcinoma is associated with freedom from prostate-specific antigen failure.

PubMed

Ko, Eric C; Stone, Nelson N; Stock, Richard G

2012-06-01

Because limited information exists regarding whether the rate or magnitude of PSA decline following brachytherapy predicts long-term clinical outcomes, we evaluated whether achieving a prostate-specific antigen (PSA) nadir (nPSA) <0.5 ng/mL following brachytherapy is associated with decreased PSA failure and/or distant metastasis. We retrospectively analyzed our database of early-stage prostate adenocarcinoma patients who underwent brachytherapy, excluding those receiving androgen-deprivation therapy and those with <2 years follow-up. Median and mean pretreatment PSA were 6 ng/mL and 7.16 ng/mL, respectively. By clinical stage, 775 were low risk (≤ T2a), 126 were intermediate risk (T2b), and 20 were high risk (>T2b). By Gleason score, 840 were low risk (≤ 6), 71 were intermediate risk (7), and 10 were high risk (>7). Patients were treated with brachytherapy only (I-125, n = 779, or Pd-103, n = 47), or brachytherapy + external-beam radiation therapy (n = 95). Median follow-up was 6.3 years. We noted whether nPSA <0.5 ng/mL was achieved and the time to achieve this nadir and tested for associations with pretreatment risk factors. We also determined whether this PSA endpoint was associated with decreased PSA failure or distant metastasis. Absence of high-risk factors in clinical stage (≤ T2b), Gleason score (≤ 7), and pretreatment PSA (≤ 20 ng/mL) was significantly associated with achieving nPSA <0.5 ng/mL. By Kaplan-Meier analysis, patients achieving nPSA <0.5 ng/mL had significantly higher long-term freedom from biochemical failure (FFBF) than nonresponders (5-year FFBF: 95.2 ± 0.8% vs. 71.5 ± 6.7%; p < 0.0005). Among responders, those who achieved nPSA <0.5 ng/mL in ≤ 5 years had higher FFBF than those requiring >5 years (5-year FFBF: 96.7 ± 0.7% vs. 80.8 ± 4.6%; p < 0.0005). On multivariate analysis, patients who achieved nPSA <0.5 ng/mL in ≤ 5 years had significantly higher FFBF than other patients. Pretreatment risk factors (clinical tumor

Final report on the torque key komparison CCM.T-K1.2 measurand torque: 0 N.m, 500 N.m, 1000 N.m

NASA Astrophysics Data System (ADS)

Röske, Dirk

2015-01-01

The purpose of the CIPM subsequent bilateral comparison CCM.T-K1.2 was to link another participant, namely the National Institute of Metrology (Thailand), in short NIMT, to the CCM.T-K1 torque key comparison. The measuring capabilities up to 1000 N.m of dead-weight torque standard machines with supported lever were investigated. The pilot laboratory was the same in both comparisons—it was the Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany). The same two very stable torque transducers with well-known properties were used as travelling standards. The measurements at the participating laboratory were carried out between November 2007 and February 2008. According to the technical protocol, torque steps of 500 N.m and 1000 N.m had to be measured both in clockwise and anticlockwise directions. Corrections had to be applied to the results reported by the participants taking into account the use of different amplifiers, the creep (due to different loading times of the machines) and the environmental conditions in the laboratories (temperature and relative humidity of the ambient air). The results of the pilot laboratory in this bilateral comparison are in very good agreement with the same results obtained in the CCM.T-K1 comparison. For each of the transducers, the two torque steps and both senses of direction of the torque vector, the key comparison reference value of the CCM.T-K1 was taken, and the results of participant NIMT were calculated with respect to these values. The agreement between the results is very good. The smallest expanded (k = 2) relative uncertainty of the machine stated by the participant is 1 × 10-4. The results of the comparison support this uncertainty statement. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM, according

Infinitely many {N}=1 dualities from m + 1 - m = 1

NASA Astrophysics Data System (ADS)

Agarwal, Prarit; Intriligator, Kenneth; Song, Jaewon

2015-10-01

We discuss two infinite classes of 4d supersymmetric theories, T N ( m) and {U}_N^{(m)} , labelled by an arbitrary non-negative integer, m. The T N ( m) theory arises from the 6d, A N - 1 type N=(2,0) theory reduced on a 3-punctured sphere, with normal bundle given by line bundles of degree ( m + 1 , - m); the m = 0 case is the N=2 supersymmetric T N theory. The novelty is the negative-degree line bundle. The {U}_N^{(m)} theories likewise arise from the 6d N=(2,0) theory on a 4-punctured sphere, and can be regarded as gluing together two (partially Higgsed) T N ( m) theories. The T N ( m) and {U}_N^{(m)} theories can be represented, in various duality frames, as quiver gauge theories, built from T N components via gauging and nilpotent Higgsing. We analyze the RG flow of the {U}_N^{(m)} theories, and find that, for all integer m > 0, they end up at the same IR SCFT as SU( N) SQCD with 2 N flavors and quartic superpotential. The {U}_N^{(m)} theories can thus be regarded as an infinite set of UV completions, dual to SQCD with N f = 2 N c . The {U}_N^{(m)} duals have different duality frame quiver representations, with 2 m + 1 gauge nodes.

N-[2-(2,2-Di-methyl-propanamido)-pyrimidin-4-yl]-2,2-di-methyl-propanamide n-hexane 0.25-solvate hemihydrate.

PubMed

Ośmiałowski, Borys; Valkonen, Arto; Chęcińska, Lilianna

2013-10-05

The asymmetric unit of the title compound, C14H22N4O2·0.25C6H14·0.5H2O, contains two independent mol-ecules of 2,4-bis-(pivaloyl-amino)-pyrimidine (M) with similar conformations, one water mol-ecule and one-half n-hexane solvent mol-ecule situated on an inversion center. In one independent M mol-ecule, one of the two tert-butyl groups is rotationally disordered between two orientations in a 3:2 ratio. The n-hexane solvent mol-ecule is disordered between two conformations in the same ratio. The water mol-ecule bridges two independent M mol-ecules via O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds into a 2M·H2O unit, and these units are further linked by N-H⋯N hydrogen bonds into chains running in the [010] direction. Weak C-H⋯O inter-actions are observed between the adjacent chains.

Dielectric and piezoelectric properties of lead-free Ba0.85Ca0.15Ti0.9-xZr0.1CuxO3 ceramics synthesized by a hydrothermal method

NASA Astrophysics Data System (ADS)

Hunpratub, Sitchai; Phokha, Sumalin; Maensiri, Santi; Chindaprasirt, Prinya

2016-04-01

Ba0.85Ca0.15Ti0.9Zr0.1-xCuxO3 (BCTZC) nanopowders were synthesized using a hydrothermal method after which they were pressed into discs and sintered in air at 1300 °C for 3 h to form ceramic samples. The phase and microstructure of the powder and ceramic samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results indicated that the ceramic samples exhibited a tetragonal structure and that CuO, BaZrO3 or CaTiO3 impurity phases, which had been present in the powder samples, were not observed. The average grain sizes in the ceramic samples were found to be 17.0, 16.1, 20.0, 18.1 and 19.6 μm for Cu mole fractions x of 0.002, 0.004, 0.006, 0.008 and 0.01, respectively. The dielectric constants, ferroelectric hysteresis loops and piezoelectric charge coefficients of the BCZTC ceramic samples were also investigated. Optimum values for the relative dielectric constant (ɛ‧), tan δ and piezoelectric charge coefficient (d33) of the samples were 3830, 0.03 and 306 pC/N, respectively, in the Cu mole fraction samples with x = 0.002.

Luminescence emission from nonpolar Al0.3Ga0.7N/GaN core-shell and core-multi-shell nanowires

NASA Astrophysics Data System (ADS)

Namvari, E.; Shojaei, S.; Asgari, A.

2017-12-01

In the present work, we theoretically study the possibility of luminescence emission from two systems of nonpolar Al0.3Ga0.7N/GaN Core-shell and core-multi-shell c-axis oriented nanowires with hexagonal cross section. To obtain energy levels and wave functions through the solution of Schrodinger-Poisson equations, numerical Self-consistent procedure has been employed. N-type doping has been considered to investigate the two-dimensional electron gas formation and its effect on luminescence. The detailed analysis of the results as a function of the various structural parameters has been carried out. The results presents an examination of the band to band luminescence feature and its changes with involved parameters. We found that the size of the system determines the feature of luminescence emission. As main finding, our calculations show that the intensity of luminescence spectrum in facet to facet route of NW cross section is significant than that of corner to corner route. In addition, no shift of the peak position is observed with changing the amount of doping. Our numerical calculations give more insights into the luminescence emission of nonpolar GaN/AlGaN core/shell nanowire and have many implications in experiment.

Utility approach to decision-making in extended T1 and limited T2 glottic carcinoma.

PubMed

van Loon, Yda; Stiggelbout, Anne M; Hakkesteegt, Marieke M; Langeveld, Ton P M; de Jong, Rob J Baatenburg; Sjögren, Elisabeth V

2017-04-01

It is still undecided if endoscopic laser surgery or radiotherapy is the preferable treatment in extended T1 and limited T2 glottic tumors. Health utilities assessed from patients can aid in decision-making. Patients treated for extended T1 or limited T2 glottic carcinoma by laser surgery (n = 12) or radiotherapy (n = 14) assigned health utilities using a visual analog scale (VAS), time tradeoff (TTO) technique and scored their voice handicap using the Voice Handicap Index (VHI). VAS and TTO scores were slightly lower for the laser group compared to the radiotherapy group, however, not significantly so. The VHI showed a correlation with the VAS score, which was very low in both groups and can be considered (near) normal. Patients show no clear preference for the outcomes of laser surgery or radiotherapy from a quality of life (QOL) or voice handicap point of view. These data can now be incorporated into decision-making models. © 2017 Wiley Periodicals, Inc. Head Neck, 2017 © 2016 Wiley Periodicals, Inc. Head Neck 39: 779-785, 2017. © 2017 Wiley Periodicals, Inc.

Study of optical properties of BaMn1-xCrxO3 (x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5) manganites using microwave synthesis method

NASA Astrophysics Data System (ADS)

Rani, Reena; Yadav, Kamlesh

2015-08-01

Barium manganite (BaMnO3), a perovskite based material, has been studied extensively. BaMnO3 properties can be changed by doping different elements at manganese (Mn) lattice site. We have prepared BaMnO3 and BaMn1-xCrxO3 (x=0.1, 0.2, 0.3, 0.4, 0.5) by Microwave Synthesizer. Data obtained from Fourier Transform Infrared Spectroscopy (FTIR) that the band gap of pure BaMnO3 is less as compare to the Cr doped BaMnO3. It is also clear from the FTIR that the band gap decreased with increasing the concentration of chromium. Broaden peak at 3201 cm-1 correspond to the stretching vibration of hydroxyl group (OH or H2O). The peaks appear on 724, 863 and 974 cm-1 is corresponding to the stretching vibration of metal oxide (M-O) bonds in the BaMnO3. BaMnO3 have applications in memory storage devices.

Enhancement of thermoelectric figure-of-merit at low temperatures by titanium substitution for hafnium in n-type half-Heuslers Hf0.75-xTixZr0.25NiSn0.99Sb0.01

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

Joshi, Giri; Dahal, Tulashi; Chen, Shuo

The effect of titanium (Ti) substitution for hafnium (Hf) on thermoelectric properties of (Hf, Zr)-based n-type half-Heuslers: Hf0.75-xTixZr0.25NiSn0.99Sb0.01, has been studied. The samples are made by arc melting followed by ball milling and hot pressing via the nanostructuring approach. A peak thermoelectric figure-of-merit (ZT) of ~1.0 is achieved at 500 °C in samples with a composition of Hf0.5Zr0.25Ti0.25NiSn0.99Sb0.01 due to a slight increase in carrier concentration and also a lower thermal conductivity caused by Ti. The ZT values below 500 °C of hot pressed Hf0.5Zr0.25Ti0.25NiSn0.99Sb0.01 samples are significantly higher than those of the same way prepared Hf0.75Zr0.25NiSn0.99Sb0.01 samples at eachmore » temperature, which are very much desired for mid-range temperature applications such as waste heat recovery in automobiles.« less

Enhancement of thermoelectric figure-of-merit at low temperatures by titanium substitution for hafnium in n-type half-Heuslers Hf0.75-xTixZr0.25NiSn0.99Sb0.01

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

Joshi, Giri; Dahal, Tulashi; Chen, Shuo

The effect of titanium (Ti) substitution for hafnium (Hf) on thermoelectric properties of (Hf, Zr)-based n-type half-Heuslers: Hf 0.75-xTi xZr 0.25NiSn 0.99Sb 0.01, has been studied. The samples are made by arc melting followed by ball milling and hot pressing via the nanostructuring approach. A peak thermoelectric figure-of-merit (ZT) of ~1.0 is achieved at 500 °C in samples with a composition of Hf 0.5Zr 0.25Ti 0.25NiSn 0.99Sb 0.01 due to a slight increase in carrier concentration and also a lower thermal conductivity caused by Ti. TheZT values below 500 °C of hot pressed Hf 0.5Zr 0.25Ti 0.25NiSn 0.99Sb 0.01 samplesmore » are significantly higher than those of the same way prepared Hf 0.75Zr 0.25NiSn 0.99Sb 0.01samples at each temperature, which are very much desired for mid-range temperature applications such as waste heat recovery in automobiles.« less

Undergraduate Education with the WIYN 0.9-m Telescope

NASA Astrophysics Data System (ADS)

Pilachowski, Catherine A.

2017-01-01

Several models have been explored at Indiana University Bloomington for undergraduate student engagement in astronomy using the WIYN 0.9-m telescope at Kitt Peak. These models include individual student research projects using the telescope, student observations as part of an observational techniques course for majors, and enrichment activities for non-science majors in general education courses. Where possible, we arrange for students to travel to the telescope. More often, we are able to use simple online tools such as Skype and VNC viewers to give students an authentic observing experience. Experiences with the telescope motivate students to learn basic content in astronomy, including the celestial sphere, the electromagnetic spectrum, telescopes and detectors, the variety of astronomical objects, date reduction processes, image analysis, and color image creation and appreciation. The WIYN 0.9-m telescope is an essential tool for our program at all levels of undergraduate education

Epitaxy of Zn{sub 2}TiO{sub 4} (1 1 1) thin films on GaN (0 0 1)

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

Hsiao, Chu-Yun; Wu, Jhih-Cheng; Shih, Chuan-Feng, E-mail: cfshih@mail.ncku.edu.tw

2013-03-15

Highlights: ► High-permittivity spinel Zn{sub 2}TiO{sub 4} thin films were grown on GaN (0 0 1) by sputtering. ► Oxygen atmosphere and post heat-treatment annealing effectively enhanced epitaxy. ► The epitaxial Zn{sub 2}TiO{sub 4} modifies the dielectric properties of ceramic oxide. - Abstract: High-permittivity spinel Zn{sub 2}TiO{sub 4} thin films were grown on GaN (0 0 1) by rf-sputtering. Grazing-angle, powder, and pole-figure X-ray diffractometries (XRD) were performed to identify the crystallinity and the preferred orientation of the Zn{sub 2}TiO{sub 4} films. Lattice image at the Zn{sub 2}TiO{sub 4} (1 1 1)/GaN (0 0 1) interface was obtained by high-resolutionmore » transmission-electron microscopy (HR-TEM). An oxygen atmosphere in sputtering and post heat-treatment using rapid thermal annealing effectively enhanced the epitaxy. The epitaxial relationship was determined from the XRD and HR-TEM results: (111){sub Zn{sub 2TiO{sub 4}}}||(001){sub GaN}, (202{sup ¯}){sub Zn{sub 2TiO{sub 4}}}||(110){sub GaN},and[21{sup ¯}1{sup ¯}]{sub Zn{sub 2TiO{sub 4}}}||[01{sup ¯}10]{sub GaN}. Finally, the relative permittivity, interfacial trap density and the flat-band voltage of the Zn{sub 2}TiO{sub 4} based capacitor were ∼18.9, 8.38 × 10{sup 11} eV{sup −1} cm{sup −2}, and 1.1 V, respectively, indicating the potential applications of the Zn{sub 2}TiO{sub 4} thin film to the GaN-based metal-oxide-semiconductor capacitor.« less

Surface and bulk electronic structures of unintentionally and Mg-doped In0.7Ga0.3N epilayer by hard X-ray photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Imura, Masataka; Tsuda, Shunsuke; Takeda, Hiroyuki; Nagata, Takahiro; Banal, Ryan G.; Yoshikawa, Hideki; Yang, AnLi; Yamashita, Yoshiyuki; Kobayashi, Keisuke; Koide, Yasuo; Yamaguchi, Tomohiro; Kaneko, Masamitsu; Uematsu, Nao; Wang, Ke; Araki, Tsutomu; Nanishi, Yasushi

2018-03-01

The surface and bulk electronic structures of In0.7Ga0.3N epilayers are investigated by angle-resolved hard X-ray photoelectron spectroscopy (HX-PES) combined with soft X-PES. The unintentionally and Mg-doped In0.7Ga0.3N (u-In0.7Ga0.3N and In0.7Ga0.3N:Mg, respectively) epilayers are grown by radio-frequency plasma-assisted molecular beam epitaxy. Here three samples with different Mg concentrations ([Mg] = 0, 7 × 1019, and 4 × 1020 cm-3) are chosen for comparison. It is found that a large downward energy band bending exists in all samples due to the formation of a surface electron accumulation (SEA) layer. For u-In0.7Ga0.3N epilayer, band bending as large as 0.8 ± 0.05 eV occurs from bulk to surface. Judged from the valence band spectral edge and numerical analysis of energy band with a surface quantum well, the valence band maximum (VBM) with respect to Fermi energy (EF) level in the bulk is determined to be 1.22 ± 0.05 eV. In contrast, for In0.7Ga0.3N:Mg epilayers, the band bending increases and the VBM only in the bulk tends to shift toward the EF level owing to the Mg acceptor doping. Hence, the energy band is considered to exhibit a downward bending structure due to the coexistence of the n+ SEA layer and Mg-doped p layer formed in the bulk. When [Mg] changes from 7 × 1019 to 4 × 1020 cm-3, the peak split occurs in HX-PES spectra under the bulk sensitive condition. This result indicates that the energy band forms an anomalous downward bending structure with a singular point due to the generation of a thin depleted region at the n+ p interface. For In0.7Ga0.3N:Mg epilayers, the VBM in the bulk is assumed to be slightly lower than EF level within 0.1 eV.

Anomaly of strings of 6d {N}=(1,0) theories

NASA Astrophysics Data System (ADS)

Shimizu, Hiroyuki; Tachikawa, Yuji

2016-11-01

We obtain the anomaly polynomial of strings of general 6d {N}=(1,0) theories in terms of anomaly inflow. Our computation sheds some light on the reason why the simplest 6d {N}=(1,0) theory has E 8 flavor symmetry, and also partially explains a curious numerology in F-theory.

Enhancement of two dimensional electron gas concentrations due to Si{sub 3}N{sub 4} passivation on Al{sub 0.3}Ga{sub 0.7}N/GaN heterostructure: strain and interface capacitance analysis

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

Dinara, Syed Mukulika, E-mail: smdinara.iit@gmail.com; Jana, Sanjay Kr.; Ghosh, Saptarsi

2015-04-15

Enhancement of two dimensional electron gas (2DEG) concentrations at Al{sub 0.3}Ga{sub 0.7}N/GaN hetero interface after a-Si{sub 3}N{sub 4} (SiN) passivation has been investigated from non-destructive High Resolution X-ray Diffraction (HRXRD) analysis, depletion depth and capacitance-voltage (C-V) profile measurement. The crystalline quality and strained in-plane lattice parameters of Al{sub 0.3}Ga{sub 0.7}N and GaN were evaluated from double axis (002) symmetric (ω-2θ) diffraction scan and double axis (105) asymmetric reciprocal space mapping (DA RSM) which revealed that the tensile strain of the Al{sub 0.3}Ga{sub 0.7}N layer increased by 15.6% after SiN passivation. In accordance with the predictions from theoretical solution of Schrödinger-Poisson’smore » equations, both electrochemical capacitance voltage (ECV) depletion depth profile and C-V characteristics analyses were performed which implied effective 9.5% increase in 2DEG carrier density after passivation. The enhancement of polarization charges results from increased tensile strain in the Al{sub 0.3}Ga{sub 0.7}N layer and also due to the decreased surface states at the interface of SiN/Al{sub 0.3}Ga{sub 0.7}N layer, effectively improving the carrier confinement at the interface.« less

The Study of Al0.29Ga0.71N-BASED Schottky Photodiodes Grown on Silicon by Plasma-Assisted Molecular Beam Epitaxy

NASA Astrophysics Data System (ADS)

Mohd Yusoff, M. Z.; Hassan, Z.; Chin, C. W.; Hassan, H. Abu; Abdullah, M. J.; Mohammad, N. N.; Ahmad, M. A.; Yusof, Y.

2013-05-01

In this paper, the growth and characterization of epitaxial Al0.29Ga0.71N grown on Si(111) by RF-plasma assisted molecular beam epitaxy (MBE) are described. The Al mole fraction was derived from the HR-XRD symmetric rocking curve (RC) ω/2θ scans of (0002) plane as x = 0.29. PL spectrum of sample has shown sharp and intense band edge emission of GaN without the existence of yellow emission band, showing that it is comparable in crystal quality of the sample when compared with previous reports. From the Raman measurement of as-grown Al0.29Ga0.71N layer on GaN/AlN/Si sample. We found that the dominant E2 (high) phonon mode of GaN appears at 572.7 cm-1. The E2 (high) mode of AlN appears at 656.7 cm-1 and deviates from the standard value of 655 cm-1 for unstrained AlN. Finally, AlGaN Schottky photodiode have been fabricated and analyzed by mean of electrical characterization, using current-voltage (I-V) measurement to evaluate the performance of this device.

History of Non-Muscle-Invasive Bladder Cancer May Have a Worse Prognostic Impact in cT2-4aN0M0 Bladder Cancer Patients Treated With Radical Cystectomy.

PubMed

Kayama, Emina; Kikuchi, Eiji; Fukumoto, Keishiro; Shirotake, Suguru; Miyazaki, Yasumasa; Hakozaki, Kyohei; Kaneko, Gou; Yoshimine, Shunsuke; Tanaka, Nobuyuki; Takahiro, Maeda; Kanai, Kunimitsu; Oyama, Masafumi; Nakajima, Yosuke; Hara, Satoshi; Monma, Tetsuo; Oya, Mototsugu

2018-04-28

To investigate whether a history of non-muscle-invasive bladder cancer (NMIBC) plays a prognostic role in patients with muscle-invasive bladder cancer (MIBC) treated with radical cystectomy in the era when neoadjuvant chemotherapy was established as standard therapy for MIBC. A total of 282 patients who were diagnosed with cT2-T4aN0M0 bladder cancer treated with open radical cystectomy at our institutions were included. Initially diagnosed MIBC without a history of NMIBC was defined as primary MIBC group (n = 231), and MIBC that progressed from NMIBC was defined as progressive MIBC (n = 51). The rate of cT3/4a tumors was significantly higher in the primary MIBC group than in the progressive MIBC group (P = .004). Five-year recurrence-free survival and cancer-specific survival (CSS) rates for the primary MIBC group versus progressive MIBC group were 68.2% versus 55.9% (P = .039) and 76.1% versus 61.6% (P = .005), respectively. Progressive MIBC (hazard ratio, 2.170; P = .008) was independently associated with cancer death. In the primary MIBC group, the 5-year CSS rate in patients treated with neoadjuvant chemotherapy was 85.4%, which was significantly higher than that in patients without (71.5%, P = .023). In the progressive MIBC group, no significant differences were observed in CSS between patients treated with and without neoadjuvant chemotherapy. MIBC that progressed from NMIBC had a significantly worse clinical outcome than MIBC without a history of NMIBC and may not respond as well to neoadjuvant chemotherapy. These results are informative, even for NMIBC patients treated with conservative intravesical therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Impact ionisation in Al0.9Ga0.1As0.08Sb0.92 for Sb-based avalanche photodiodes

NASA Astrophysics Data System (ADS)

Collins, X.; Craig, A. P.; Roblin, T.; Marshall, A. R. J.

2018-01-01

We report the impact ionisation coefficients of the quaternary alloy Al0.9Ga0.1As0.08Sb0.92 lattice matched to GaSb substrates within the field range of 150 to 550 kV cm-1 using p-i-n and n-i-p diodes of various intrinsic thicknesses. The coefficients were found with an evolutionary fitting algorithm using a non-local recurrence based multiplication model and a variable electric field profile. These coefficients indicate that an avalanche photodiode not only can be designed to be a function in the mid-wave infrared but also can be operated at lower voltages. This is due to the high magnitude of the impact ionisation coefficients at relatively low fields compared to other III-V materials typically used in avalanche multiplication regions.

Management of complex glottic stenosis in children with recurrent respiratory papillomatosis.

PubMed

Siegel, Bianca; Smith, Lee P

2013-10-01

To describe our management of complex glottic stenosis in tracheotomy dependent children with severe recurrent respiratory papillomatosis. Retrospective chart review at a tertiary care children's hospital. Three children with complex glottic stenosis secondary to severe recurrent respiratory papillomatosis were treated at our institution since 2011. Two patients had complete stenosis, and the third had near-complete stenosis. Two patients were managed using balloon dilation alone, and the third also underwent laryngotracheal reconstruction with posterior costal cartilage grafting. Two patients have been successfully decannulated and the third has been tolerating continuous tracheotomy capping for greater than twelve months. All three patients underwent aggressive debridement of papillomatosis and balloon dilation every 4-6 weeks until their burden of disease was controlled. In two patients, the glottic airway was patent, and the third continued to have complete restenosis between procedures and required laryngotracheoplasty with multiple post-operative dilation procedures to establish an adequate glottic airway. Severe laryngeal stenosis is a well-described complication of recurrent respiratory papillomatosis, but its management is not well-defined. Aggressive management of papillomatosis with frequent debridement is critical in successfully managing laryngeal stenosis. Balloon dilation alone may be surprisingly effective in these patients, and laryngotracheoplasty can be used as an adjunct procedure in those patients who fail balloon dilation. Given the quality of life issues and concerns regarding distal spread of disease with tracheotomies in these patients, we feel that aggressive management and early decannulation is in the patient's best interest. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effect of V/III ratio on the surface morphology and electrical properties of m-plane (10 1 bar 0) GaN homoepitaxial layers

NASA Astrophysics Data System (ADS)

Barry, Ousmane I.; Tanaka, Atsushi; Nagamatsu, Kentaro; Bae, Si-Young; Lekhal, Kaddour; Matsushita, Junya; Deki, Manato; Nitta, Shugo; Honda, Yoshio; Amano, Hiroshi

2017-06-01

We have investigated the effect of V/III ratio on the surface morphology, impurity concentration and electrical properties of m-plane (10 1 bar 0) Gallium Nitride (GaN) homoepitaxial layers. Four-sided pyramidal hillocks are observed on the nominally on-axis m-plane GaN films. Hillocks sizes relatively increase by increasing the V/III ratio. All facets of pyramidal hillocks exhibit well-defined step-terrace features. Secondary ion mass spectrometry depth profiles reveal that carbon impurities decrease by increasing the V/III ratio while the lowest oxygen content is found at an optimized V/III ratio of 900. Vertical Schottky barrier diodes fabricated on the m-GaN samples were characterized. Low leakage current densities of the order of 10-10 A/cm2 at -5 V are obtained at the optimum V/III ratio. Oxygen impurities and screw-component dislocations around hillocks are found to have more detrimental impact on the leakage current mechanism.

LP01 to LP0m mode converters using all-fiber two-stage tapers

NASA Astrophysics Data System (ADS)

Mellah, Hakim; Zhang, Xiupu; Shen, Dongya

2015-11-01

A mode converter between LP01 and LP0m modes is proposed using two stages of tapers. The first stage is formed by an adiabatically tapering a circular fiber to excite the desirable LP0m mode. The second stage is formed by inserting an inner core (tapered from both sides) with a refractive index smaller than the original core. This second stage is used to obtain low insertion loss and high extinction ratio of the desired LP0m mode. Three converters between LP01 and LP0m, m=2, 3, and 4, are designed for C-band, and simulation results show that less than 0.24, 0.54 and 0.7 dB insertion loss and higher than 15, 16, and 17.5 dB extinction ratio over the entire band were obtained for the three converters, respectively.

Undergraduate Research Possibilities with a 0.6m Telescope

NASA Astrophysics Data System (ADS)

Carini, M. T.; Barnaby, D.; Gelderman, R.; Marchenko, S.; McGruder, C. H., III; Strolger, L.

2005-12-01

We present a discussion of the research projects that are being carried out by undergraduate students with the 0.6m telescope at the Bell Observatory, operated by Western Kentucky University. As a primarily undergraduate institution, our goal is to provide a meaningful undergraduate educational experience through both quality instruction and engagement of students in mentored research activities. Such activities not only enhance the student's educational experience, but also prepare them to be competitive in graduate school and/or the workplace. Using our modernized 0.6m telescope, our students pursue research projects which investigate a variety of astrophysically interesting problems: variability of Blazars, eclipsing binary stars, Gamma-ray burst identifications and follow up, photometric searches for extra-solar planets, supernova monitoring and survey programs, the relationship between morphological disturbances and activity in Seyfert nuclei, and variability in Wolf Rayet stars. We discuss the instrumentation, projects and results obtained by our undergraduate students, and the impact this has had on their undergraduate experience.

A surface complexation model of YREE sorption on Ulva lactuca in 0.05-5.0 M NaCl solutions

NASA Astrophysics Data System (ADS)

Zoll, Alison M.; Schijf, Johan

2012-11-01

We present distribution coefficients, log iKS, for the sorption of yttrium and the rare earth elements (YREEs) on BCR-279, a dehydrated tissue homogenate of a marine macroalga, Ulva lactuca, resembling materials featured in chemical engineering studies aimed at designing renewable biosorbents. Sorption experiments were conducted in NaCl solutions of different ionic strength (0.05, 0.5, and 5.0 M) at T = 25 °C over the pH range 2.7-8.5. Distribution coefficients based on separation of the dissolved and particulate phase by conventional filtration (<0.22 μm) were corrected for the effect of colloid-bound YREEs (>3 kDa) using an existing pH-dependent model. Colloid-corrected values were renormalized to free-cation concentrations by accounting for YREE hydrolysis and chloride complexation. At each ionic strength, the pH dependence of the renormalized values is accurately described with a non-electrostatic surface complexation model (SCM) that incorporates YREE binding to three monoprotic functional groups, previously characterized by alkalimetric titration, as well as binding of YREE-hydroxide complexes (MOH2+) to the least acidic one (pKa ∼ 9.5). In non-linear regressions of the distribution coefficients as a function of pH, each pKa was fixed at its reported value, while stability constants of the four YREE surface complexes were used as adjustable parameters. Data for a single fresh U. lactuca specimen in 0.5 M NaCl show generally the same pH-dependent behavior but a lower degree of sorption and were excluded from the regressions. Good linear free-energy relations (LFERs) between stability constants of the YREE-acetate and YREE-hydroxide solution complex and surface complexes with the first and third functional group, respectively, support their prior tentative identifications as carboxyl and phenol. A similar confirmation for the second group is precluded by insufficient knowledge of the stability of YREE-phosphate complexes and a perceived lack of YREE binding

Temperature and electric-field induced phase transitions, and full tensor properties of [011] C-poled domain-engineered tetragonal 0 .63 Pb (M g1 /3N b2 /3) -0 .37 PbTi O3 single crystals

NASA Astrophysics Data System (ADS)

Zheng, Limei; Jing, Yujia; Lu, Xiaoyan; Wang, Ruixue; Liu, Gang; Lü, Weiming; Zhang, Rui; Cao, Wenwu

2016-03-01

The phase-transition sequence of 0.67 Pb (M g1 /3N b2 /3)- 0.37 PbTi O3 (PMN-0.37PT) single crystals driven by the electric (E ) field and temperature is comprehensively studied. Based on the strain-E field loop, polarization-E field loop, and the evolution of domain configurations, the E field along the [011] C induced phase transitions have been confirmed to be as follows: tetragonal (T ) → monoclinic (MC)→ single domain orthorhombic (O ) phase. As the E field decreases, the induced O phase cannot be maintained and transformed to the MC phase, then to the coexistence state of MC and T phases. In addition, the complete sets of dielectric, piezoelectric, and elastic constants for the [011] C-poled domain-engineered PMN-0.37PT single crystal were measured at room temperature, which show high longitudinal dielectric, piezoelectric, and electromechanical properties (ɛ33T=10 661 ,d33=1052 pC /N , and k33= 0.766 ). Our results revealed that the MC phase plays an important role in the high electromechanical properties of this domain-engineered single crystal. The temperature dependence of the domain configuration revealed that the volume fraction of the MC phase decreases with temperature accompanied by the reduction of ɛ33T,d31, and k31 due to the substantially smaller intrinsic properties of the T phase.

Two-step iron(0)-mediated N-demethylation of N-methyl alkaloids.

PubMed

Kok, Gaik B; Pye, Cory C; Singer, Robert D; Scammells, Peter J

2010-07-16

A mild and simple two-step Fe(0)-mediated N-demethylation of a number of tertiary N-methyl alkaloids is described. The tertiary N-methylamine is first oxidized to the corresponding N-oxide, which is isolated as the hydrochloride salt. Subsequent treatment of the N-oxide hydrochloride with iron powder readily provides the N-demethylated amine. Representative substrates include a number of opiate and tropane alkaloids. Key intermediates in the synthesis of semisynthetic 14-hydroxy pharmaceutical opiates such as oxycodone and oxymorphone are also readily N-demethylated using this method.

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.

Positron probes of the Ge(1 0 0) surface: The effects of surface reconstructions and electron positron correlations on positron trapping and annihilation characteristics

NASA Astrophysics Data System (ADS)

Fazleev, N. G.; Jung, E.; Weiss, A. H.

2007-08-01

Positron annihilation induced Auger electron spectroscopy (PAES) has been applied to study the Ge(1 0 0) surface. The high-resolution PAES spectrum from the Ge(1 0 0) surface displays several strong Auger peaks corresponding to M4,5N1N2,3, M2,3M4,5M4,5, M2,3M4,5V and M1M4,5M4,5 Auger transitions. The integrated peak intensities of Auger transitions are used to obtain experimental annihilation probabilities for the Ge 3d and 3p core level electrons. These experimental results are analyzed by performing calculations of positron surface states and annihilation characteristics of surface trapped positrons with relevant Ge core-level electrons for the non-reconstructed and reconstructed Ge(1 0 0)-p(2 × 1), Ge(1 0 0)-p(2 × 2) and Ge(1 0 0)-c(4 × 2) surfaces. It is found that the positron surface state wave function extends into the Ge lattice in the regions where atoms are displaced from their ideal terminated positions due to reconstructions. Estimates of the positron binding energy and the positron annihilation characteristics reveal their sensitivity to the specific atomic structure of the topmost layers of Ge(1 0 0). A comparison with PAES data reveals an agreement with theoretical core annihilation probabilities for the Auger transitions considered.

First principles study of α2-Ti3Al(0 0 0 1) surface and γ-TiAl(1 1 1)/α2-Ti3Al(0 0 0 1) interfaces

NASA Astrophysics Data System (ADS)

Wang, Lu; Shang, Jia-Xiang; Wang, Fu-He; Zhang, Yue

2013-07-01

The α2-Ti3Al(0 0 0 1) surface and γ-TiAl(1 1 1)/α2-Ti3Al(0 0 0 1) interfaces with six orientation relationships are studied by using the first-principle density functional theory. The calculated results indicate that the Ti3Al(0 0 0 1) surface has a higher surface energy (1.964 J/m2) and larger surface relaxations, compared with the γ-TiAl(1 1 1) surface. For the γ-TiAl(1 1 1)/α2-Ti3Al(0 0 0 1) interface structures, the work of separation along Ti3Al(0 0 0 1) cleavage plane is larger than that along TiAl(1 1 1) plane. In the interface region, the bonding strengths between Ti3Al layers and between TiAl layers are smaller than those along Ti3Al(0 0 0 1) plane and TiAl(1 1 1) plane in the bulk materials, respectively. The heterogeneous interface would be the weak link in the material, and the bonding strength of interface depends on the weaker one of the two phases. The bonding characteristics of interface are analyzed by the electron local function.

Magnetic and magnetocaloric properties of La{sub 0.6}Pr{sub 0.1}Sr{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} (0≤x≤0.3) manganites

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

Cherif, R., E-mail: cherifrim18@yahoo.fr; Hlil, E.K.; Ellouze, M.

2014-07-01

The La{sub 0.6}Pr{sub 0.1}Sr{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} (x=0, 0.1, 0.2 and 0.3) samples have been elaborated by the solid-state reaction method. X-ray powder diffraction shows that all the samples crystallize in a rhombohedric phase with R3{sup ¯}c space group. The variation of magnetization as a function of temperature and applied magnetic field was carried out. The samples for x=0 and 0.1 exhibit a FM–PM transition at the Curie temperature T{sub C}, however, for x=0.2 and 0.3 exhibit an AFM–PM one at the Neel temperature T{sub N}, when the temperature increases. A magneto-caloric effect has been calculated in terms ofmore » isothermal magnetic entropy change. A large magneto-caloric effect has been observed, the maximum entropy change, |ΔS{sub M}{sup max}|, reaches the highest value of 3.28 J/kgK under a magnetic field change of 5 T with an RCP value of 220 J/kg for La{sub 0.6}Pr{sub 0.1}Sr{sub 0.3}MnO{sub 3} composition, which will be an interesting compound for application materials working as magnetic refrigerants near room temperature. - Graphical abstract: Magnetic entropy change versus temperature and applied magnetic field for x=0.1 (a) and RCP versus applied magnetic field for x=0, 0.1 (b). - Highlights: • The La{sub 0.6}Pr{sub 0.1}Sr{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} (0≤x≤0.3) polycrystalline samples were prepared by the solid state reaction method. • Crystalline and magnetic structures were investigated using DRX and magnetization measurements. • The magnetocaloric (MC) effect was estimated versus magnetic field and temperatures. • Compounds with x=0, 0.1 exhibit great potential for magnetic refrigeration at room temperature.« less

CO2 laser versus cold steel margin analysis following endoscopic excision of glottic cancer

PubMed Central

2014-01-01

Objective To compare the suitability of CO2 laser with steel instruments for margin excision in transoral laser microsurgery. Methods Prospective randomized blinded study. Patients with glottic cancer undergoing laser resection were randomized to margin excision by either steel instruments or CO2 laser. Margins were analyzed for size, interpretability and degree of artifact by a pathologist who was blinded to technique. Results 45 patients were enrolled in the study with 226 total margins taken. 39 margins taken by laser had marked artifact and 0 were uninterpretable. 20 margins taken by steel instruments had marked artifact, and 2 were uninterpretable. Controlling for margin size, the laser technique was associated with increasing degrees of margin artifact (p = 0.210), but there was no difference in crude rates of uninterpretability (p = 0.24). Conclusion Laser margin excision is associated with a greater degree of artifact than steel instrument excision, but was not associated with higher rate of uninterpretability. PMID:24502856

Selective area deposited n-Al0.5Ga0.5N channel field effect transistors with high solar-blind ultraviolet photo-responsivity

NASA Astrophysics Data System (ADS)

Muhtadi, S.; Hwang, S.; Coleman, A.; Asif, F.; Lunev, A.; Chandrashekhar, M. V. S.; Khan, A.

2017-04-01

We report on AlGaN field effect transistors over AlN/sapphire templates with selective area grown n-Al0.5Ga0.5N channel layers for which a field-effect mobility of 55 cm2/V-sec was measured. Using a pulsed plasma enhanced chemical vapor deposition deposited 100 A thick SiO2 layer as the gate-insulator, the gate-leakage currents were reduced by three orders of magnitude. These devices with or without gate insulators are excellent solar-blind ultraviolet detectors, and they can be operated either in the photoconductive or the photo-voltaic modes. In the photo-conductive mode, gain arising from hole-trapping in the depletion region leads to steady-state photoresponsivity as high as 1.2 × 106A/W at 254 nm, which drops sharply below 290 nm. A hole-trapping limited detector response time of 34 ms, fast enough for real-time flame-detection and imaging applications, was estimated.

Study on Dy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ-Ce0.85Gd0.15O1.95 composite cathode material for intermediate temperature solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Kautkar, Pranay R.; Acharya, Smita A.

2018-05-01

xDy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ - xCe0.85Gd0.15O1.95 (x = 50 %) composite cathode supported on Ce0.85Gd0.15O1.95 (GDC15) electrolyte are studied for applications in IT-SOFCs. Results attribute that Dy0.45Ba0.05Sr0.5Co0.8Fe0.2O3-δ material is chemically compatible with Ce0.85Gd0.15O1.95 (GDC15). Rietveld refined X-ray diffraction patterns notify orthorhombic (space group:Pbnm) symmetry for Dy0.45 Ba0.05Sr0.5Co0.8Fe0.2O3-δ and fluorite type structure (space group: Fm-3m) symmetry for GDC15. The polarization resistance (Rp) of composite cathode reduces to the minimum value of 1.35 Ω cm2 at 650 °C in air. Area specific resistance (ASR) of composite cathode has found 0.67 Ω.cm2 at 650°C respectively. Result shows that the surface diffusion of the dissociative adsorbed oxygen at electrode/electrolyte interface on the composite cathode.

Comparative influence study of gate-formation structuring on Al0.22Ga0.78As/In0.16Ga0.84As/Al0.22Ga0.78As double heterojunction high electron mobility transistors

NASA Astrophysics Data System (ADS)

Hsu, M. K.; Chiu, S. Y.; Wu, C. H.; Guo, D. F.; Lour, W. S.

2008-12-01

Pseudomorphic Al0.22Ga0.78As/In0.16Ga0.84As/Al0.22Ga0.78As double heterojunction high electron mobility transistors (DH-HEMTs) fabricated with different gate-formation structures of a single-recess gate (SRG), a double-recess gate (DRG) and a field-plate gate (FPG) were comparatively investigated. FPG devices show the best breakdown characteristics among these devices due to great reduction in the peak electric field between the drain and gate electrodes. The measured gate-drain breakdown voltages defined at a 1 mA mm-1 reverse gate-drain current density were -15.3, -19.1 and -26.0 V for SRG, DRG and FPG devices, respectively. No significant differences in their room-temperature common-source current-voltage characteristics were observed. However, FPG devices exhibit threshold voltages being the least sensitive to temperature. Threshold voltages as a function of temperature indicate a threshold-voltage variation as low as -0.97 mV K-1 for FPG devices. According to the 2.4 GHz load-pull power measurement at VDS = 3.0 V and VGS = -0.5 V, the saturated output power (POUT), power gain (GP) and maximum power-added efficiency (PAE) were 10.3 dBm/13.2 dB/36.6%, 11.2 dBm/13.1 dB/39.7% and 13.06 dBm/12.8 dB/47.3%, respectively, for SRG, DRG and FPG devices with a pi-gate in class AB operation. When the FPG device is biased at a VDS of 10 V, the saturated power density is more than 600 mW mm-1.

Anode-supported single-chamber solid oxide fuel cell based on cobalt-free composite cathode of Nd0.5Sr0.5Fe0.8Cu0.2O3-δ-Sm0.2Ce0.8O1.9 at intermediate temperatures

NASA Astrophysics Data System (ADS)

Yin, Jie-Wei; Zhang, Chunming; Yin, Yi-Mei; Shi, Huangang; Lin, Ye; Lu, Jun; Ma, Zi-Feng

2015-07-01

As a candidate of cathode material of single-chamber solid oxide fuel cell (SC-SOFC), cobalt-free mixed ionic electronic conductor (MIEC) Nd0.5Sr0.5Fe0.8Cu0.2O3-δ (NSFCu) is synthesized by sol-gel method with ethylene diamine tetraacetic acid and citric acid as co-complexing agents. The XRD shows NSFCu is stable after CO2 treatment and chemical compatible with SDC at high temperatures. CO2-TPD (CO2-temperature programmed desorption) demonstrates both CO2 adsorption and desorption phenomenon on NSFCu surface. However, the polarization resistances (Rp) of NSFCu and SDC (10:4 in weight) composite electrodes showed no decay in 5% CO2. Single cell using N2-O2-CH4 mixed gas (CH4 to O2 ratio = 1.5) as fuel shows maximum power density of 635 mW cm-2 at 700 °C. These results suggest that NSFCu-SDC is a promising composite cathode material for application in single-chamber solid oxide fuel cell.

Interpreting the structural and electrochemical complexity of 0.5Li{sub 2}MnO{sub 3}{lg_bullet}.0.5LiMO{sub 2} electrodes for lithium batteries (M=Mn{sub 0.5-x}Ni{sub 0.5-x}Co{sub 2x}, 0{le}x{le}0.5).

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

Kang, S. H.; Kempgens, P.; Greenbaum, S.

2007-01-01

The structural and electrochemical features of layered 0.5Li{sub 2}MnO{sub 3} {center_dot} 0.5LiMO{sub 2} electrodes, in which M = Mn{sub 0.5-x}Ni{sub 0.5-x}Co{sub 2x} (0{le} x {le} 0.5), have been studied by powder X-ray diffraction, electrochemical differential-capacity measurements, {sup 7}Li magic-angle-spinning nuclear magnetic resonance, and X-ray absorption near-edge spectroscopy. Li{sub 2}MnO{sub 3}-like regions in the as-prepared samples were observed for all values of x, with transition-metal cation disorder between the LiMO{sub 2} and Li{sub 2}MnO{sub 3} components increasing with cobalt content (i.e., the value of x). The structural disorder and complexity of the electrochemical redox reactions increase when the Li{sub 2}MnO{sub 3}-likemore » regions within the electrode are activated to 4.6 V in lithium cells; interpretations of structural and electrochemical phenomena are provided.« less

The operation of 0.35 μm partially depleted SOI CMOS technology in extreme environments

NASA Astrophysics Data System (ADS)

Li, Ying; Niu, Guofu; Cressler, John D.; Patel, Jagdish; Liu, S. T.; Reed, Robert A.; Mojarradi, Mohammad M.; Blalock, Benjamin J.

2003-06-01

We evaluate the usefulness of partially depleted SOI CMOS devices fabricated in a 0.35 μm technology on UNIBOND material for electronics applications requiring robust operation under extreme environment conditions consisting of low and/or high temperature, and under substantial radiation exposure. The threshold voltage, effective mobility, and the impact ionization parameters were determined across temperature for both the nFETs and the pFETs. The radiation response was characterized using threshold voltage shifts of both the front-gate and back-gate transistors. These results suggest that this 0.35 μm partially depleted SOI CMOS technology is suitable for operation across a wide range of extreme environment conditions consisting of: cryogenic temperatures down to 86 K, elevated temperatures up to 573 K, and under radiation exposure to 1.3 Mrad(Si) total dose.

Effects of Post Annealing on I-V-T Characteristics of (Ni/Au)/Al0.09Ga0.91N Schottky Barrier Diodes

NASA Astrophysics Data System (ADS)

Akkaya, Abdullah; Ayyıldız, Enise

2016-04-01

Post annealing is a simple, effective and suitable method for improving the diode parameters, especially when the used chemically stable substrates like Si, III-N and ternary alloys. In our work, we were applied this method to (Ni/Au)/Al0.09Ga0.91N Schottky Barrier Diodes (SBDs) and investigated by temperature-dependent current-voltage (I-V-T) characteristics at optimum conditions. Optimum annealing temperature was 600°C, which it’s determined with respect to have a highest barrier height value. The temperature-dependent electrical characteristics of the annealed at 600°C (Ni/Au)/Al0.09Ga0.91N SBDs were investigated in the wide temperature range of 95-315K. The diode parameters such as ideality factor (n) and Schottky barrier height (Vb0) were obtained to be strongly temperature dependent. The observed variation in Vb0 and n can be attributed to the spatial barrier inhomogeneities in Schottky barrier height by assuming a triple Gaussian distribution (TGD) of barrier heights (BHs) at 95-145K, 145-230K and 230-315K. The modified Richardson plots and T0 analysis was performed to provide an experimental Richardson constants and bias coefficients of the mean barrier height. Furthermore, the chemical composition of the contacts was examined by the XPS depth profile analysis.

Measurements of the absolute neutron fluence spectrum emitted at 0/sup 0/ and 90/sup 0/ from the Little-Boy replica

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

Roberts, J.H.; Gold, R.; Preston, C.C.

Nuclear research emulsions (NRE) have been used to characterize the neutron spectrum emitted by the Little-Boy replica. NRE were irradiated at the Little-Boy surface as well as approximately 2m from the center of the Little-Boy replica using polar angles of 0/sup 0/, 30/sup 0/, 60/sup 0/ and 90/sup 0/. For the NRE exposed at 2m, neutron background was determined using shadow shields of borated polyethylene. Emulsion scanning to date has concentrated exclusively on the 2m, 0/sup 0/ and 2m, 90/sup 0/ locations. Approximately 5000 proton-recoil tracks have been measured in NRE irradiated at each of these locations. At the 2m,more » 90/sup 0/ location the NRE neutron spectrum extends from 0.37 up to 8.2 MeV, whereas the NRE neutron spectrum at the 2m, 0/sup 0/ location is much softer and extends only up to 2.7 MeV. NRE neutron spectrometry results at these two locations are compared with both liquid scintillator neutron spectrometry and Monte Carlo calculations. 7 refs., 3 figs.« less

Thermally stable In0.7Ga0.3As/In0.52Al0.48As pHEMTs using thermally evaporated palladium gate metallization

NASA Astrophysics Data System (ADS)

Ian, Ka Wa; Zawawiand, Mohamad Adzhar Md; Missous, Mohamed

2014-03-01

This work described the fabrication and performances of strained channel In0.52Al0.47As/In0.7Ga0.3As/InP pHEMTs with thermally evaporated Pd/Ti/Au gate metallization. The electrical characteristics of these Pd-gate devices are studied to investigate the effects of changing the Pd metal thickness, annealing temperature and annealing time. Following annealing at 200 °C for 35 min, a 10 nm Pd-gate device displays a VTH of -0.25 V, which is significantly smaller compared to those with Ti/Au gate schemes showing VTH = -0.75 V. A 1 um gate length device exhibits an improved Gm of 580 mS mm-1 (from 500 mS mm-1), a high IDSmax of 400 mA mm-1 (from 330 mA mm-1) and good fT and fmax of 24.5 and 49 GHz commensurate with the 1 µm gate length. All these enhancements are attributed to the controllable gate sinking of Pd. The device shows no significant degradation even after annealing at 230 °C for more than 5 h, which implies that the reliability of these Pd-gate structures is excellent.

Fabrication of 80-nm T-gate high indium In0.7Ga0.3As/In0.6Ga0.4As composite channels mHEMT on GaAs substrate with simple technological process

NASA Astrophysics Data System (ADS)

Xian, Ji; Xiaodong, Zhang; Weihua, Kang; Zhili, Zhang; Jiahui, Zhou; Wenjun, Xu; Qi, Li; Gongli, Xiao; Zhijun, Yin; Yong, Cai; Baoshun, Zhang; Haiou, Li

2016-02-01

An 80-nm gate length metamorphic high electron mobility transistor (mHEMT) on a GaAs substrate with high indium composite compound-channels In0.7Ga0.3 As/In0.6Ga0.4 As and an optimized grade buffer scheme is presented. High 2-DEG Hall mobility values of 10200 cm2/(V·s) and a sheet density of 3.5 × 1012 cm-2 at 300 K have been achieved. The device's T-shaped gate was made by utilizing a simple three layers electron beam resist, instead of employing a passivation layer for the T-share gate, which is beneficial to decreasing parasitic capacitance and parasitic resistance of the gate and simplifying the device manufacturing process. The ohmic contact resistance Rc is 0.2 ω·mm when using the same metal system with the gate (Pt/Ti/Pt/Au), which reduces the manufacturing cycle of the device. The mHEMT device demonstrates excellent DC and RF characteristics. The peak extrinsic transconductance of 1.1 S/mm and the maximum drain current density of 0.86 A/mm are obtained. The unity current gain cut-off frequency (fT) and the maximum oscillation frequency (fmax) are 246 and 301 GHz, respectively. Project supported by the Key Laboratory of Nano-Devices and Applications, Nano-Fabrication Facility of SINANO, Chinese Academy of Sciences, the National Natural Science Foundation of China (Nos. 61274077, 61474031, 61464003), the Guangxi Natural Science Foundation (Nos. 2013GXNSFGA019003, 2013GXNSFAA019335), the National Basic Research Program of China (Nos. 2011CBA00605, 2010CB327501), the Project (No. 9140C140101140C14069), and the Innovation Project of GUET Graduate Education (Nos. GDYCSZ201448, GDYCSZ201449, YJCXS201529).

Influence of Zr substitution on the stabilization of ThMn{sub 12}-type (Nd{sub 1−α}Zr{sub α})(Fe{sub 0.75}Co{sub 0.25}){sub 11.25}Ti{sub 0.75}N{sub 1.2−1.4} (α = 0–0.3) compounds

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

Sakuma, N.; Yano, M.; Kato, A.

2016-05-15

The influence of Zr substitution in ThMn{sub 12} compounds was investigated using strip casting alloys. It was found that Zr substitution stabilized (Nd{sub 1−α}Zr{sub α})(Fe{sub 0.75}Co{sub 0.25}){sub 11.25}Ti{sub 0.75}N{sub 1.2−1.4} (α = 0–0.3) compounds. Specifically, a reduction in the lattice constant along the a-axis was observed. Energy-dispersive X-ray spectroscopy mapping combined with Cs-corrected scanning transmission electron microscopy indicated that Zr atoms preferentially occupied Nd 2a sites. Both the magnetic anisotropy field and saturation polarization were maximum at Zr substitution ratio α = 0.1. The (Nd{sub 1−α}Zr{sub α})(Fe{sub 0.75}Co{sub 0.25}){sub 11.25}Ti{sub 0.75}N{sub 1.2−1.4} (α = 0–0.3) compounds displayed higher saturation polarizationmore » than Nd{sub 2}Fe{sub 14}B at high temperatures.« less

Fabrication and thermoelectric properties of n-type (Sr0.9Gd0.1)TiO3 oxides

NASA Astrophysics Data System (ADS)

Li, Liangliang; Qin, Xiaoying; Liu, Yongfei; Xin, Hongxing; Zhang, Jian; Li, Di; Song, Chunjun; Guo, Guanglei; Dou, Yunchen; Zou, Tianhua

2014-02-01

The n-type oxides (Sr0.9Gd0.1)TiO3 (SGTO) have been successfully prepared via a sol-gel process followed by solid-state sintering. The effects of sintering temperature on the thermoelectric (TE) properties of the SGTO samples have been investigated. The Seebeck coefficient showed no obvious difference, while the electrical conductivity increased with increasing sintering temperature, benefiting from an enhancement of densification. The maximum power factor (PF) value, 20.5μW/K2cm at 370 K in the metallic region, was observed for the sample sintered at 1748 K. As a result, the peak figure of merit (ZT) values for the samples sintered at higher than 1673 K were in the range of 0.28-0.30. All the results indicate that such synthetic method provides a simple and effective way to prepare TE oxides.

No evidence of persisting unrepaired nuclear DNA single strand breaks in distinct types of cells in the brain, kidney, and liver of adult mice after continuous eight-week 50 Hz magnetic field exposure with flux density of 0.1 mT or 1.0 mT.

PubMed

Korr, Hubert; Angstman, Nicholas B; Born, Tatjana B; Bosse, Kerstin; Brauns, Birka; Demmler, Martin; Fueller, Katja; Kántor, Orsolya; Kever, Barbara M; Rahimyar, Navida; Salimi, Sepideh; Silny, Jiri; Schmitz, Christoph

2014-01-01

It has been hypothesized in the literature that exposure to extremely low frequency electromagnetic fields (50 or 60 Hz) may lead to human health effects such as childhood leukemia or brain tumors. In a previous study investigating multiple types of cells from brain and kidney of the mouse (Acta Neuropathologica 2004; 107: 257-264), we found increased unrepaired nuclear DNA single strand breaks (nDNA SSB) only in epithelial cells of the choroid plexus in the brain using autoradiographic methods after a continuous eight-week 50 Hz magnetic field (MF) exposure of adult mice with flux density of 1.5 mT. In the present study we tested the hypothesis that MF exposure with lower flux densities (0.1 mT, i.e., the actual exposure limit for the population in most European countries, and 1.0 mT) shows similar results to those in the previous study. Experiments and data analysis were carried out in a similar way as in our previous study. Continuous eight-week 50 Hz MF exposure with 0.1 mT or 1.0 mT did not result in increased persisting unrepaired nDNA SSB in distinct types of cells in the brain, kidney, and liver of adult mice. MF exposure with 1.0 mT led to reduced unscheduled DNA synthesis (UDS) in epithelial cells in the choroid plexus of the fourth ventricle in the brain (EC-CP) and epithelial cells of the cortical collecting duct in the kidney, as well as to reduced mtDNA synthesis in neurons of the caudate nucleus in the brain and in EC-CP. No evidence was found for increased persisting unrepaired nDNA SSB in distinct types of cells in the brain, kidney, and liver of adult mice after continuous eight-week 50 Hz magnetic field exposure with flux density of 0.1 mT or 1.0 mT.

Direct evidence for double-exchange coupling in Ru- substituted La0.7Pb0.3Mn 1 - x Ru x O3, 0.0 <= x <= 0.4

NASA Astrophysics Data System (ADS)

Sundar Manoharan, S.; Sahu, R. K.; Rao, M. L.; Elefant, D.; Schneider, C. M.

2002-08-01

The La0.7Pb0.3Mn 1 - x Ru x O3 (0.0 <= x <= 0.4) system shows an innate relationship between Mn and Ru ions by a unique double-exchange mediated transport behavior. This is exonerated by the coexistence of Tp and Tc (range 330 K 245 K for 0.0 <= x <= 0.4). For Ru > 30%, the hole carrier mass influences the transport property. X-ray absorption spectra suggest that the Tc-Tp match is due to the transport mediated by the Mn3+/Mn4+ leftrightarrow Ru4+/Ru5+ redox pair and also due to the broad low-spin Ru:4d conduction band. For x > 0.2, T < 0.5Tc obeys a modified variable-range hopping model, where kT0 propto (M/Ms)2, suggesting a random magnetic potential which localizes the charge carriers.

Infinitely many $$ \\mathcal{N}=1 $$ dualities from m + 1 - m = 1

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

Agarwal, Prarit; Intriligator, Kenneth; Song, Jaewon

2015-10-06

We discuss two infinite classes of 4d supersymmetric theories, T N (m) and Umore » $$(m)\\atop{N}$$, labelled by an arbitrary non-negative integer, m. The T N (m) theory arises from the 6d, A N-1 type N=(2,0) theory reduced on a 3-punctured sphere, with normal bundle given by line bundles of degree (m + 1, -m); the m = 0 case is the N=2 supersymmetric T N theory. The novelty is the negative-degree line bundle. The U$$(m)\\atop{N}$$ theories likewise arise from the 6d N=(2,0) theory on a 4-punctured sphere, and can be regarded as gluing together two (partially Higgsed) T N (m) theories. The T N (m) and U$$(m)\\atop{N}$$ theories can be represented, in various duality frames, as quiver gauge theories, built from T N components via gauging and nilpotent Higgsing. We analyze the RG flow of the U($$(m)\\atop{N}$$ theories, and find that, for all integer m > 0, they end up at the same IR SCFT as SU(N) SQCD with 2N flavors and quartic superpotential. The U$$(m)\\atop{N}$$ theories can thus be regarded as an infinite set of UV completions, dual to SQCD with N f = 2N c. The U$$(m)\\atop{N}$$ duals have different duality frame quiver representations, with 2m + 1 gauge nodes.« less

In vitro T lymphocyte adherence capabilities under the influence of lower induction values (0.1 - 0.01 mT) of 50 Hz external magnetic fields

NASA Astrophysics Data System (ADS)

Čoček, A.; Jandová, A.; Hahn, A.; Mártonová, J.; Ambruš, M.; Dohnalová, A.; Nedbalová, M.; Pokorný, J.

2011-12-01

Our research thus far has concerned the impact of external magnetic fields (50 Hz) and low (0.01-10 mT) induction on adherence capabilities of T lymphocytes obtained from the blood of patients with head and neck tumors. We know that the in vitro adherence capability of T lymphocytes towards surfaces in cancer patients is less than that of control. Previously, we have found that exposure to magnetic fields (50 Hz / 0.01-10 mT) increases the capability of T lymphocytes, in larynx/pharynx cancer patients, to adhere in vitro to surfaces, achieving almost physiological values, in not only pre-treatment patients but also those receiving treatment in the course of follow-up. The capability of T lymphocytes in controls (voluntary blood donors) to adhere to surfaces was also increased (50 Hz / 0.01-0.5 mT). The present study concentrates on the significance of the level of magnetic field induction in order to determine whether low induction values can restore T lymphocytes adherence capabilities. Testing a set of 20 patients showed a statistically significant difference (p < 0.05) in the in vitro adherence capacity of T lymphocytes between both 0.01 and 0.05, and 0.1 mT induction levels. In the control group (patients diagnosed with chronic sensorineural hearing loss) there was even a statistically significant difference between induction values of 0.05 and 0.01 mT. Therefore, we concluded that lower induction values resulted in a more biologically significant response.

n-type thermoelectric material Mg2Sn0.75Ge0.25 for high power generation

PubMed Central

Liu, Weishu; Kim, Hee Seok; Chen, Shuo; Jie, Qing; Lv, Bing; Yao, Mengliang; Ren, Zhensong; Opeil, Cyril P.; Wilson, Stephen; Chu, Ching-Wu; Ren, Zhifeng

2015-01-01

Thermoelectric power generation is one of the most promising techniques to use the huge amount of waste heat and solar energy. Traditionally, high thermoelectric figure-of-merit, ZT, has been the only parameter pursued for high conversion efficiency. Here, we emphasize that a high power factor (PF) is equivalently important for high power generation, in addition to high efficiency. A new n-type Mg2Sn-based material, Mg2Sn0.75Ge0.25, is a good example to meet the dual requirements in efficiency and output power. It was found that Mg2Sn0.75Ge0.25 has an average ZT of 0.9 and PF of 52 μW⋅cm−1⋅K−2 over the temperature range of 25–450 °C, a peak ZT of 1.4 at 450 °C, and peak PF of 55 μW⋅cm−1⋅K−2 at 350 °C. By using the energy balance of one-dimensional heat flow equation, leg efficiency and output power were calculated with Th = 400 °C and Tc = 50 °C to be of 10.5% and 6.6 W⋅cm−2 under a temperature gradient of 150 °C⋅mm−1, respectively. PMID:25733845

Evidence of type-II band alignment in III-nitride semiconductors: experimental and theoretical investigation for In 0.17 Al 0.83 N/GaN heterostructures.

PubMed

Wang, Jiaming; Xu, Fujun; Zhang, Xia; An, Wei; Li, Xin-Zheng; Song, Jie; Ge, Weikun; Tian, Guangshan; Lu, Jing; Wang, Xinqiang; Tang, Ning; Yang, Zhijian; Li, Wei; Wang, Weiying; Jin, Peng; Chen, Yonghai; Shen, Bo

2014-10-06

Type-II band alignment structure is coveted in the design of photovoltaic devices and detectors, since it is beneficial for the transport of photogenerated carriers. Regrettably, for group-III-nitride wide bandgap semiconductors, all existing devices are limited to type-I heterostructures, owing to the unavailable of type-II ones. This seriously restricts the designing flexibility for optoelectronic devices and consequently the relevant performance of this material system. Here we show a brandnew type-II band alignment of the lattice-matched In 0.17 Al 0.83 N/GaN heterostructure from the perspective of both experimental observations and first-principle theoretical calculations. The band discontinuity is dominated by the conduction band offset ΔEC, with a small contribution from the valence band offset ΔEV which equals 0.1 eV (with E(AlInN(VBM) being above E(GaN)(VBM)). Our work may open up new prospects to realize high-performance III-Nitrides optoelectronic devices based on type-II energy band engineering.

Lattice damage and compositional changes in Xe ion irradiated In{sub x}Ga{sub 1-x}N (x = 0.32−1.0) single crystals

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

Zhang, Limin, E-mail: zhanglm@lzu.edu.cn; Peng, Jinxin; Ai, Wensi

2016-06-28

Lattice disorder and compositional changes in In{sub x}Ga{sub 1-x}N (x = 0.32, 0.47, 0.7, 0.8, and 1.0) films on GaN/Al{sub 2}O{sub 3} substrates, induced by room-temperature irradiation of 5 MeV Xe ions, have been investigated using both Rutherford backscattering spectrometry under ion-channeling conditions and time-of-flight secondary ion mass spectrometry. The results show that for a fluence of 3 × 10{sup 13 }cm{sup −2}, the relative level of lattice disorder in In{sub x}Ga{sub 1-x}N increases monotonically from 59% to 90% with increasing indium concentration x from 0.32 to 0.7; a further increase in x up to 1.0 leads to little increase in the disorder level. In contrastmore » to Ga-rich In{sub x}Ga{sub 1-x}N (x = 0.32 and 0.47), significant volume swelling of up to ∼25% accompanied with oxidation in In-rich In{sub x}Ga{sub 1-x}N (x = 0.7, 0.8, and 1.0) is observed. In addition, irradiation-induced atomic mixing occurs at the interface of In-rich In{sub x}Ga{sub 1-x}N and GaN. The results from this study indicate an extreme susceptibility of the high In-content In{sub x}Ga{sub 1-x}N to heavy-ion irradiation, and suggest that cautions must be exercised in applying ion-implantation techniques to these materials at room temperature. Further studies of the irradiation behavior at elevated temperatures are warranted.« less

Bias current dependence of resistivity in Co0.4Fe0.4B0.2 ultrathin film prepared by RF magnetron sputtering

NASA Astrophysics Data System (ADS)

Mandal, Snehal; Mazumdar, Dipak; Das, I.

2018-04-01

Ultrathin film of Co0.4Fe0.4B0.2 was prepared on p-type Si (100) substrate by RF magnetron sputtering. X-Ray Reflectivity and Atomic Force Microscopy measurements were performed to estimate the thickness and surface roughness of the film. Electrical transport measurements were performed by four-probe method in a current-in-plane (CIP) geometry. Presence of non-linearity in the current-voltage (I-V) characteristics was observed at higher current range. The electrical resistivity was found to change by several orders of magnitude (105) by changing the bias current from nano-ampere (nA) to milli-ampere (mA) range. This bias current dependence of the resistivity has been explained by different transport mechanisms.

Randomized Crossover Comparison of Injection Site Pain with 40 mg/0.4 or 0.8 mL Formulations of Adalimumab in Patients with Rheumatoid Arthritis.

PubMed

Nash, Peter; Vanhoof, Johan; Hall, Stephen; Arulmani, Udayasankar; Tarzynski-Potempa, Rita; Unnebrink, Kristina; Payne, Andrew N; Cividino, Alfred

2016-12-01

Adalimumab, an anti-tumor necrosis factor antibody, is currently available in a 40 mg/0.8 mL formulation. The objective of this analysis was to evaluate injection site-related pain, safety, and tolerability of a 40 mg/0.4 mL formulation of adalimumab that had fewer excipients, a smaller volume, and a delivery presentation with a smaller gauge needle, versus the current 40 mg/0.8 mL formulation in patients with rheumatoid arthritis (RA). Two identically designed, phase 2, randomized, single-blind, two-period crossover studies were conducted in Belgium and the Czech Republic (Study 1) and Australia, Canada, and Germany (Study 2). In both studies, adults with RA [biologic-naive or current users of 40 mg/0.8 mL adalimumab with an average injection site-related pain rating ≥3 cm on a visual analog scale (VAS; 0-10 cm)] were randomized to receive 40 mg/0.8 mL or 40 mg/0.4 mL adalimumab at visit 1. After 1-2 weeks (depending on patient medication schedule), patients received the other formulation at visit 2. A pain VAS [McGill Pain Questionnaire (MPQ-SF)] and the Draize scale were evaluated immediately after injection and 15 min postinjection. The primary endpoint was immediate pain after injection. 64 and 61 patients were randomized in Studies 1 and 2, respectively. Both studies found a clinically relevant and statistically significant lower immediate pain after injection for the 40 mg/0.4 mL versus the 40 mg/0.8 mL formulation. The mean difference on the VAS for the pooled data (-2.48 cm) was also clinically relevant. Most other endpoints in both studies favored the 40 mg/0.4 mL formulation, and its tolerability and safety profile were consistent with 40 mg/0.8 mL adalimumab. A 40 mg/0.4 mL adalimumab formulation was well tolerated and associated with less injection site-related pain than the 40 mg/0.8 mL adalimumab formulation. ClinicalTrials.gov identifier, NCT01561313 and NCT01502423. AbbVie.

Reducing Mg Acceptor Activation-Energy in Al0.83Ga0.17N Disorder Alloy Substituted by Nanoscale (AlN)5/(GaN)1 Superlattice Using MgGa δ-Doping: Mg Local-Structure Effect

NASA Astrophysics Data System (ADS)

Zhong, Hong-Xia; Shi, Jun-Jie; Zhang, Min; Jiang, Xin-He; Huang, Pu; Ding, Yi-Min

2014-10-01

Improving p-type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)5/(GaN)1 superlattice (SL), a substitution for Al0.83Ga0.17N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al0.83Ga0.17N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 1019 cm-3 can be obtained in (AlN)5/(GaN)1 SL by MgGa δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN.

Reducing Mg Acceptor Activation-Energy in Al0.83Ga0.17N Disorder Alloy Substituted by Nanoscale (AlN)5/(GaN)1 Superlattice Using MgGa δ-Doping: Mg Local-Structure Effect

PubMed Central

Zhong, Hong-xia; Shi, Jun-jie; Zhang, Min; Jiang, Xin-he; Huang, Pu; Ding, Yi-min

2014-01-01

Improving p-type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)5/(GaN)1 superlattice (SL), a substitution for Al0.83Ga0.17N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al0.83Ga0.17N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 1019 cm−3 can be obtained in (AlN)5/(GaN)1 SL by MgGa δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN. PMID:25338639

Reducing Mg acceptor activation-energy in Al(0.83)Ga(0.17)N disorder alloy substituted by nanoscale (AlN)₅/(GaN)₁ superlattice using Mg(Ga) δ-doping: Mg local-structure effect.

PubMed

Zhong, Hong-xia; Shi, Jun-jie; Zhang, Min; Jiang, Xin-he; Huang, Pu; Ding, Yi-min

2014-10-23

Improving p-type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)5/(GaN)1 superlattice (SL), a substitution for Al(0.83)Ga(0.17)N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al(0.83)Ga(0.17)N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 10(19) cm(-3) can be obtained in (AlN)5/(GaN)1 SL by Mg(Ga) δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN.

Diffuse Phase Transitions and Giant Electrostrictive Coefficients in Lead-Free Fe3+-Doped 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 Ferroelectric Ceramics.

PubMed

Jin, Li; Huo, Renjie; Guo, Runping; Li, Fei; Wang, Dawei; Tian, Ye; Hu, Qingyuan; Wei, Xiaoyong; He, Zhanbing; Yan, Yan; Liu, Gang

2016-11-16

The electrostrictive effect has some advantages over the piezoelectric effect, including temperature stability and hysteresis-free character. In the present work, we report the diffuse phase transitions and electrostrictive properties in lead-free Fe 3+ -doped 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 (BZT-0.5BCT) ferroelectric ceramics. The doping concentration was set from 0.25 to 2 mol %. It is found that by introducing Fe 3+ ion into BZT-0.5BCT, the temperature corresponding to permittivity maximum T m was shifted toward lower temperature monotonically by 37 °C per mol % Fe 3+ ion. Simultaneously, the phase transitions gradually changed from classical ferroelectric-to-paraelectric phase transitions into diffuse phase transitions with a weak relaxor characteristic. Purely electrostrictive responses with giant electrostrictive coefficient Q 33 between 0.04 and 0.05 m 4 /C 2 are observed from 25 to 100 °C for the compositions doped with 1-2 mol % Fe 3+ ion. The Q 33 of Fe 3+ -doped BZT-0.5BCT ceramics is almost twice the Q 33 of other ferroelectric ceramics. These observations suggest that the present system can be considered as a potential lead-free material for the applications in electrostrictive area and that BT-based ferroelectric ceramics would have giant electrostrictive coefficient over other ferroelectric systems.

Metabolic Rate M[superscript 0.75] in Human Beings

ERIC Educational Resources Information Center

Agrawal. D. C.

2014-01-01

Human beings consume energy every day. Even at rest, energy is still needed for the working of the internal organs. This is achieved by the metabolism of consumed food in the presence of inhaled oxygen. During the resting state this is called the maintenance rate, and follows the mouse-to-elephant formula, P[subscript met] = 70M[superscript 0.75]…

Isochrones for old (>5 Gyr) stars and stellar populations. I. Models for –2.4 ≤ [Fe/H] ≤+0.6, 0.25 ≤ Y ≤ 0.33, and –0.4 ≤ [α/Fe] ≤+0.4

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

VandenBerg, Don A.; Bergbusch, Peter A.; Ferguson, Jason W.

2014-10-10

Canonical grids of stellar evolutionary sequences have been computed for the helium mass-fraction abundances Y = 0.25, 0.29, and 0.33, and for iron abundances that vary from –2.4 to +0.4 (in 0.2 dex increments) when [α/Fe] =+0.4, or for the ranges –2.0 ≤ [Fe/H] ≤+0.6, –1.8 ≤ [Fe/H] ≤+0.6 when [α/Fe] =0.0 and –0.4, respectively. The grids, which consist of tracks for masses from 0.12 M{sub ⊙} to 1.1-1.5 M{sub ⊙} (depending on the metallicity) are based on up-to-date physics, including the gravitational settling of helium (but not metals diffusion). Interpolation software is provided to generate isochrones for arbitrary agesmore » between ≈5 and 15 Gyr and any values of Y, [α/Fe], and [Fe/H] within the aformentioned ranges. Comparisons of isochrones with published color-magnitude diagrams (CMDs) for the open clusters M67 ([Fe/H] ≈0.0) and NGC 6791 ([Fe/H] ≈0.3) and for four of the metal-poor globular clusters (47 Tuc, M3, M5, and M92) indicate that the models for the observed metallicities do a reasonably good job of reproducing the locations and slopes of the cluster main sequences and giant branches. The same conclusion is reached from a consideration of plots of nearby subdwarfs that have accurate Hipparcos parallaxes and metallicities in the range –2.0 ≲ [Fe/H] ≲ –1.0 on various CMDs and on the (log T {sub eff}, M{sub V} ) diagram. A relatively hot temperature scale similar to that derived in recent calibrations of the infrared flux method is favored by both the isochrones and the adopted color transformations, which are based on the latest MARCS model atmospheres.« less

Digital amateur observations of Venus at 0.9μm

NASA Astrophysics Data System (ADS)

Kardasis, E.

2017-09-01

Venus atmosphere is extremely dynamic, though it is very difficult to observe any features on it in the visible and even in the near-IR range. Digital observations with planetary cameras in recent years routinely produce high-quality images, especially in the near-infrared (0.7-1μm), since IR wavelengths are less influenced by Earth's atmosphere and Venus's atmosphere is partially transparent in this spectral region. Continuous observations over a few hours may track dark atmospheric features in the dayside and determine their motion. In this work we will present such observations and some dark-feature motion measurements at 0.9μm. Ground-based observations at this wavelength are rare and are complementary to in situ observations by JAXA's Akatsuki orbiter, that studies the atmospheric dynamics of Venus also in this band with the IR1 camera.

Electrochemical performances of Al-0.5Mg-0.1Sn-0.02In alloy in different solutions for Al-air battery

NASA Astrophysics Data System (ADS)

Jingling, Ma; Jiuba, Wen; Hongxi, Zhu; Quanan, Li

2015-10-01

In this research, the corrosion behavior and the electrochemical performances of Al-0.5Mg-0.1Sn-0.02In (wt.%) alloy have been investigated in 2 M NaCl, 4 M NaOH ethanol-10% water, 4 M NaOH solutions. The results show that the optimal electrochemical properties are obtained in 4 M NaOH ethanol-water solutions, and the alloy has higher anodic utilization and lower self-corrosion rate in the solutions compared to 2 M NaCl or 4 M aqueous NaOH. SEM and EIS results of the alloy are in good agreement with corrosion characteristics. By comparison with the electrochemical performance of Zn in 4 M NaOH solutions, the feasibility of using Al-0.5Mg-0.1Sn-0.02In alloy as anode material for a high power density Al-air battery in 4 M NaOH ethanol-water solutions is demonstrated.

Design of Nickel-Based Cation-Disordered Rock-Salt Oxides: The Effect of Transition Metal (M = V, Ti, Zr) Substitution in LiNi0.5M0.5O2 Binary Systems.

PubMed

Cambaz, Musa Ali; Vinayan, Bhaghavathi P; Euchner, Holger; Johnsen, Rune E; Guda, Alexander A; Mazilkin, Andrey; Rusalev, Yury V; Trigub, Alexander L; Gross, Axel; Fichtner, Maximilian

2018-06-20

Cation-disordered oxides have been ignored as positive electrode material for a long time due to structurally limited lithium insertion/extraction capabilities. In this work, a case study is carried out on nickel-based cation-disordered Fm3 ̅m LiNi 0.5 M 0.5 O 2 positive electrode materials. The present investigation targets tailoring the electrochemical properties for nickel-based cation-disordered rock-salt by electronic considerations. The compositional space for binary LiM +3 O 2 with metals active for +3/+4 redox couples is extended to ternary oxides with LiA 0.5 B 0.5 O 2 with A = Ni 2+ and B = Ti 4+ , Zr 4+ , and V +4 to assess the impact of the different transition metals in the isostructural oxides. The direct synthesis of various new unknown ternary nickel-based Fm3̅ m cation-disordered rock-salt positive electrode materials is presented with a particular focus on the LiNi 0.5 V 0.5 O 2 system. This positive electrode material for Li-ion batteries displays an average voltage of ∼2.55 V and a high discharge capacity of 264 mAhg -1 corresponding to 0.94 Li. For appropriate cutoff voltages, a long cycle life is achieved. The charge compensation mechanism is probed by XANES, confirming the reversible oxidation and reduction of V 4+ /V 5+ . The enhancement in the electrochemical performances within the presented compounds stresses the importance of mixed cation-disordered transition metal oxides with different electronic configuration.

A predictive model for recurrence in patients with glottic cancer implemented in a mobile application for Android.

PubMed

Jover-Esplá, Ana Gabriela; Palazón-Bru, Antonio; Folgado-de la Rosa, David Manuel; Severá-Ferrándiz, Guillermo; Sancho-Mestre, Manuela; de Juan-Herrero, Joaquín; Gil-Guillén, Vicente Francisco

2018-05-01

The existing predictive models of laryngeal cancer recurrence present limitations for clinical practice. Therefore, we constructed, internally validated and implemented in a mobile application (Android) a new model based on a points system taking into account the internationally recommended statistical methodology. This longitudinal prospective study included 189 patients with glottic cancer in 2004-2016 in a Spanish region. The main variable was time-to-recurrence, and its potential predictors were: age, gender, TNM classification, stage, smoking, alcohol consumption, and histology. A points system was developed to predict five-year risk of recurrence based on a Cox model. This was validated internally by bootstrapping, determining discrimination (C-statistics) and calibration (smooth curves). A total of 77 patients presented recurrence (40.7%) in a mean follow-up period of 3.4 ± 3.0 years. The factors in the model were: age, lymph node stage, alcohol consumption and stage. Discrimination and calibration were satisfactory. A points system was developed to obtain the probability of recurrence of laryngeal glottic cancer in five years, using five clinical variables. Our system should be validated externally in other geographical areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

Observation of B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} at Belle

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

Chang, Y.-W.; Wang, M.-Z.; Chao, Y.

2009-03-01

We study the charmless decays B{yields}{lambda}{lambda}h, where h stands for {pi}{sup +}, K{sup +}, K{sup 0},K*{sup +}, or K*{sup 0}, using a 605 fb{sup -1} data sample collected at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric energy e{sup +}e{sup -} collider. We observe B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} with branching fractions of (4.76{sub -0.68}{sup +0.84}(stat){+-}0.61(syst))x10{sup -6} and (2.46{sub -0.72}{sup +0.87}{+-}0.34)x10{sup -6}, respectively. The significances of these signals in the threshold-mass enhanced mass region, M{sub {lambda}}{sub {lambda}}<2.85 GeV/c{sup 2}, are 12.4{sigma} and 9.3{sigma}, respectively. We also update the branching fraction B(B{sup +}{yields}{lambda}{lambda}K{sup +})=(3.38{sub -0.36}{sup +0.41}{+-}0.41)x10{supmore » -6} with better accuracy, and report the following measurement or 90% confidence level upper limit in the threshold-mass-enhanced region: B(B{sup +}{yields}{lambda}{lambda}K*{sup +})=(2.19{sub -0.88}{sup +1.13}{+-}0.33)x10{sup -6} with 3.7{sigma} significance; B(B{sup +}{yields}{lambda}{lambda}{pi}{sup +})<0.94x10{sup -6}. A related search for B{sup 0}{yields}{lambda}{lambda}D{sup 0} yields a branching fraction B(B{sup 0}{yields}{lambda}{lambda}D{sup 0})=(1.05{sub -0.44}{sup +0.57}{+-}0.14)x10{sup -5}. This may be compared with the large, {approx}10{sup -4}, branching fraction observed for B{sup 0}{yields}ppD{sup 0}. The M{sub {lambda}}{sub {lambda}} enhancements near threshold and related angular distributions for the observed modes are also reported.« less

Nanomagnets La0.8Pb0.2(Fe0.8Co0.2)O3 assembled with a bonded surface graphene oxide: sensitive for sensing small gas molecules.

PubMed

Bhargav, K K; Ram, S; Majumder, S B

2012-04-01

Nanocrystallites La0.8Pb0.2(Fe0.8Co0.2)O3 (LPFC) when bonded through a surface layer (carbon) in small ensembles display surface sensitive magnetism useful for biological probes, electrodes, and toxic gas sensors. A simple dispersion and hydrolysis of the salts in ethylene glycol (EG) in water is explored to form ensembles of the nanocrystallites (NCs) by combustion of a liquid precursor gel slowly in microwave at 70-80 dgrees C (apparent) in a closed container in air. In a dilute sample, the EG molecules mediate hydrolyzed species to configure in small groups in process to form a gel. Proposed models describe how a residual carbon bridges a stable bonded layer of a graphene-oxide-like hybrid structure on the LPFC-NCs in attenuating the magnetic structure. SEM images, measured from a pelletized sample which was used to study the gas sensing features in terms of the electrical resistance, describe plate shaped NCs, typically 30-60 nm widths, 60-180 nm lengths and -50 m2/g surface area (after heating at -750 degrees C). These NCs are arranged in ensembles (200-900 nm size). As per the X-ray diffraction, the plates (a Pnma orthorhombic structure) bear only small strain -0.0023 N/m2 and oxygen vacancies. The phonon and electronic bands from a bonded surface layer disappear when it is etched out slowly by heating above 550 degrees C in air. The surface layer actively promotes selective H2 gas sensor properties.

Effect of Medialization Thyroplasty on Glottic Airway Anatomy: Cadaver Model.

PubMed

Shinghal, Tulika; Anderson, Jennifer; Chung, Janet; Hong, Aaron; Bharatha, Aditya

2016-11-01

The purpose of this study was to investigate the change in airway dimensions after medialization thyroplasty (MT) using a cadaveric model. Helical computerized tomography (CT) was performed before and after placement of a silastic block in human larynges to investigate the effect on airway anatomy at the level of the glottis. Tissue density (TD) of the medialized vocal fold (VF) was documented to understand the effect on tissue displacement. This is a cadaveric study. Thirteen human cadaveric larynges underwent fine-cut CT scan before and after MT was performed using carved blocks in two sizes (small block and large block [LB]). Clientstream software was used to measure laryngeal dimensions: intraglottic volume (IGV), cross-sectional area (CSA), posterior-glottic diameter (PGD), VF density (in Hounsfield units [HUs]), and anterior-posterior diameter (APD). Eight sequential axial sections 0.625 mm cuts) at the level of the true VFs were analyzed. There was a significant decrease between the three conditions for IGV (P < 0.0001) and CSA (P < 0.0001). TD of the VF was increased after MT as indicated by HU increase (P = 0.0003). APD was not significantly changed. PGD was significantly different between the no block to LB placement (P = 0.0012). MT significantly changes the IGV and CSA at the level of the glottis. Density in the true VF was significantly increased. These findings have important implications for understanding volumetric effects of MT. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Investigation of electrochemical migration on Sn-0.7Cu-0.3Ag-0.03P-0.005Ni solder alloy in HNO3 solution

NASA Astrophysics Data System (ADS)

Sarveswaran, C.; Othman, N. K.; Ali, M. Yusuf Tura; Ani, F. Che; Samsudin, Z.

2015-09-01

Current issue in lead-free solder in term of its reliability is still under investigation. This high impact research attempts to investigate the electrochemical migration (ECM) on Sn-0.7Cu-0.3Ag-0.03P-0.005Ni solder alloy by Water Drop Test (WDT) in different concentration of HNO3 solution. The concentration of HNO3 solution used in this research was 0.05, 0.10, 0.50 and 1M. Optical Microscope (OM), Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-Ray Analysis (EDX) were carried out in order to analysis the ECM behavior based on the growth of dendrite formation after WDT. In general, the results demonstrated that dendrite growth is faster in higher concentration compared with low concentration of HNO3. The concentration of HNO3 solution used has a strong correlation with Mean-Time-To-Failure (MTTF). As the concentration of HNO3 increases, the MTTF value decreases. Based on the MTTF results the solder alloy in 1M HNO3 solution is most susceptible to ECM. SnO2 forms as a corrosion by-product in the samples proved by EDX analysis. The solder alloy poses a high reliability risk in microelectronic devices during operation in 1M HNO3 solution.

Spin canting and magnetic transition in NixZn1-xFe2O4 (x=0.0, 0.5 and 1.0) nanoparticles

NASA Astrophysics Data System (ADS)

Rani, Stuti; Raghav, Dharmendra Singh; Yadav, Prashant; Varma, G. D.

2018-04-01

Nanoparticles of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) have been synthesized via co-precipitation method and studied thestructural and magnetic properties. Rietveld refinement of X ray diffraction data of as synthesized samples revealthat the samples have mixed spinel structure with space group Fd-3m. The lattice parameter of the samples decreases as doping concentration of Ni ions increases. Magnetic measurements show paramagnetic to ferrimagnetic transition at room temperature on Ni doping in ZnFe2O4 nanoparticles. The magnetic measurements also show spin canting in samples possibly due to their nanocrystalline nature. The spin canting angles have been calculated with the help of Yafet-Kittel (Y-K) model. Furthermore, the Law of approach (LA) fitting of M-H curves indicates that the samples are highly anisotropicin nature. The Arrot plots of as synthesized samples also indicate the paramagnetic to ferrimagnetic transition. The correlation between the structural and observed magnetic properties of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) nanocrystals will be described and discussed in this paper.

Dielectric, Piezoelectric and Variable Range Hopping Conductivity Studies of Bi0.5(Na, K)0.5TiO3 Ceramics

NASA Astrophysics Data System (ADS)

Pattipaka, Srinivas; James, A. R.; Dobbidi, Pamu

2018-04-01

We report a detailed study on the structural, microstructural, piezoelectric, dielectric and AC conductivity of Bi0.5(Na1-x K x )0.5TiO3 (BNKT; x = 0, 0.1, 0.2 and 0.3) ceramics fabricated by a conventional solid-state reaction method. XRD and Raman analysis revealed that Bi0.5(Na0.8K0.2)0.5TiO3 and Bi0.5(Na0.7K0.3)0.5TiO3 ceramics exhibit a mixture of rhombohedral and tetragonal structures. The segregation of K at the grain boundary was confirmed by transmission electron microscopy and is related to typical microstructural local compositional mapping analysis. Two transitions, at ˜ 330°C and 150°C, observed from the ɛ' versus T curve in pure BNT are associated with the ferroelectric tetragonal to paraelectric cubic phase (T C) and ferroelectric rhombohedral to ferroelectric tetragonal phase (T d), respectively. Further, the T C and T d shifted towards the lower temperature with a rise in K concentration. Frequency dispersion of T d and T C suggest that BNKT ceramics exhibit a weak relaxor behavior with diffuse phase transition, which is confirmed by Uchino-Nomura criteria and the Vogel-Fulcher law. The AC resistivity ρ ac(T) follows the Mott variable range hopping conduction mechanism. A significant enhancement of dielectric and piezoelectric properties were observed for x = 0.2 system: dielectric constant (ɛ' = 1273), dielectric loss (tanδ = 0.047) at 1 kHz, electromechanical coupling coefficients (k ij : k 33, k t ˜ 60%, k 31 ˜ 62% and k p ˜ 46%), elastic coupling coefficients ( S_{33}D = 6.40 × 10-13 m2/N and S_{33}E = 10.06 × 10-13 m2/N) and piezoelectric constants (d 33 = 64.23 pC/N and g 33 = 5.69 × 10-3 Vm/N).

Dielectric, Piezoelectric and Variable Range Hopping Conductivity Studies of Bi0.5(Na, K)0.5TiO3 Ceramics

NASA Astrophysics Data System (ADS)

Pattipaka, Srinivas; James, A. R.; Dobbidi, Pamu

2018-07-01

We report a detailed study on the structural, microstructural, piezoelectric, dielectric and AC conductivity of Bi0.5(Na1- x K x )0.5TiO3 (BNKT; x = 0, 0.1, 0.2 and 0.3) ceramics fabricated by a conventional solid-state reaction method. XRD and Raman analysis revealed that Bi0.5(Na0.8K0.2)0.5TiO3 and Bi0.5(Na0.7K0.3)0.5TiO3 ceramics exhibit a mixture of rhombohedral and tetragonal structures. The segregation of K at the grain boundary was confirmed by transmission electron microscopy and is related to typical microstructural local compositional mapping analysis. Two transitions, at ˜ 330°C and 150°C, observed from the ɛ' versus T curve in pure BNT are associated with the ferroelectric tetragonal to paraelectric cubic phase ( T C) and ferroelectric rhombohedral to ferroelectric tetragonal phase ( T d), respectively. Further, the T C and T d shifted towards the lower temperature with a rise in K concentration. Frequency dispersion of T d and T C suggest that BNKT ceramics exhibit a weak relaxor behavior with diffuse phase transition, which is confirmed by Uchino-Nomura criteria and the Vogel-Fulcher law. The AC resistivity ρ ac( T) follows the Mott variable range hopping conduction mechanism. A significant enhancement of dielectric and piezoelectric properties were observed for x = 0.2 system: dielectric constant ( ɛ' = 1273), dielectric loss (tan δ = 0.047) at 1 kHz, electromechanical coupling coefficients ( k ij : k 33, k t ˜ 60%, k 31 ˜ 62% and k p ˜ 46%), elastic coupling coefficients ( S_{33}D = 6.40 × 10-13 m2/N and S_{33}E = 10.06 × 10-13 m2/N) and piezoelectric constants ( d 33 = 64.23 pC/N and g 33 = 5.69 × 10-3 Vm/N).

5.0 kV breakdown-voltage vertical GaN p-n junction diodes

NASA Astrophysics Data System (ADS)

Ohta, Hiroshi; Hayashi, Kentaro; Horikiri, Fumimasa; Yoshino, Michitaka; Nakamura, Tohru; Mishima, Tomoyoshi

2018-04-01

A high breakdown voltage of 5.0 kV has been achieved for the first time in vertical GaN p-n junction diodes by using our newly developed guard-ring structures. A resistance device was inserted between the main diode portion and the guard-ring portion in a ring-shaped p-n diode to generate a voltage drop over the resistance device by leakage current flowing through the guard-ring portion under negatively biased conditions before breakdown. The voltage at the outer mesa edge of the guard-ring portion, where the electric field intensity is highest and the destructive breakdown usually occurs, is decreased by the voltage drop, so the electric field concentration in the portion is reduced. By adopting this structure, the breakdown voltage (V B) is raised by about 200 V. Combined with a low measured on-resistance (R on) of 1.25 mΩ cm2, Baliga’s figure of merit (V\\text{B}2/R\\text{on}) was as high as 20 GW/cm2.

Roles of Bi, M and VO{sub 4} tetrahedron in photocatalytic properties of novel Bi{sub 0.5}M{sub 0.5}VO{sub 4} (M=La, Eu, Sm and Y) solid solutions for overall water splitting

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

Liu Hui; Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University, shanghai 200240; Faculty of Engineering Sciences, Kyushu University, Fukuoka 816-8580

2012-02-15

Novel Bi{sub 0.5}M{sub 0.5}VO{sub 4} (BMV; M=La, Eu, Sm and Y) solid solutions were prepared and studied in this paper. All the samples were proved to produce H{sub 2} and O{sub 2} simultaneously from pure water under the irradiation of UV light. M-O bond lengths were proved to increase with M cations by refining cell parameters and atomic positions. Besides, band gaps, energy gaps and photocatalytic activities of BMV also changed with M cations. Both of M-O and V-O bond lengths were suggested to account for this phenomenon. Inactive A{sub 0.5}Y{sub 0.5}VO{sub 4} (A=La, Ce) for water splitting proved incorporationmore » of Bi rather than distortion of VO{sub 4} tetrahedron was a critical factor for improving efficiency of overall water splitting by facilitating the generation of electron and hole with lighter effective masses. Replacement of Bi by M cations not only gave indirect effect on band structure but also raised position of conduction band minimum to meet requirement of H{sub 2} production. - Graphical abstract: Novel Bi{sub 0.5}M{sub 0.5}VO{sub 4} (M=La, Eu, Sm and Y) solid solutions showed the high and stable photocatalytic activities for overall water splitting with their crystal radii of M elements. Highlights: Black-Right-Pointing-Pointer BMV solid solutions were novel highly efficient V-based photocatalysts for overall water splitting. Black-Right-Pointing-Pointer Photocatalytic activity of BMV solid solution related to the effective ionic radii of M cations. Black-Right-Pointing-Pointer Incorporation of Bi is one of key factors for the highly efficient activity of BMV solid solution. Black-Right-Pointing-Pointer Incorporation of Y is dispensable for H{sub 2} production.« less

Seismomagnetic effects from the long-awaited 28 September 2004 M 6.0 parkfield earthquake

USGS Publications Warehouse

Johnston, M.J.S.; Sasai, Y.; Egbert, G.D.; Mueller, R.J.

2006-01-01

Precise measurements of local magnetic fields have been obtained with a differentially connected array of seven synchronized proton magnetometers located along 60 km of the locked-to-creeping transition region of the San Andreas fault at Parkfield, California, since 1976. The M 6.0 Parkfield earthquake on 28 September 2004, occurred within this array and generated coseismic magnetic field changes of between 0.2 and 0.5 nT at five sites in the network. No preseismic magnetic field changes exceeding background noise levels are apparent in the magnetic data during the month, week, and days before the earthquake (or expected in light of the absence of measurable precursive deformation, seismicity, or pore pressure changes). Observations of electric and magnetic fields from 0.01 to 20 Hz are also made at one site near the end of the earthquake rupture and corrected for common-mode signals from the ionosphere/magnetosphere using a second site some 115 km to the northwest along the fault. These magnetic data show no indications of unusual noise before the earthquake in the ULF band (0.01-20 Hz) as suggested may have preceded the 1989 ML 7.1 Loma Prieta earthquake. Nor do we see electric field changes similar to those suggested to occur before earthquakes of this magnitude from data in Greece. Uniform and variable slip piezomagnetic models of the earthquake, derived from strain, displacement, and seismic data, generate magnetic field perturbations that are consistent with those observed by the magnetometer array. A higher rate of longer-term magnetic field change, consistent with increased loading in the region, is apparent since 1993. This accompanied an increased rate of secular shear strain observed on a two-color EDM network and a small network of borehole tensor strainmeters and increased seismicity dominated by three M 4.5-5 earthquakes roughly a year apart in 1992, 1993, and 1994. Models incorporating all of these data indicate increased slip at depth in the region

Effects of background oxygen pressure on dielectric and ferroelectric properties of epitaxial (K0.44,Na0.52,Li0.04)(Nb0.84,Ta0.10,Sb0.06)O3 thin films on SrTiO3

NASA Astrophysics Data System (ADS)

Abazari, M.; Akdoǧan, E. K.; Safari, A.

2008-11-01

Oxygen partial pressure (PO_2) in pulsed laser deposition significantly influences the composition, microstructure, and electrical properties of epitaxial misfit strain-relieved 450nm ⟨001⟩ oriented epitaxial (K0.44,Na0.52,Li0.04)(Nb0.84,Ta0.10,Sb0.06)O3 thin films on SrRuO3 coated SrTiO3. Films deposited at 400mTorr exhibit high remnant and saturated polarization of 7.5 and 16.5μC /cm2, respectively, which is ˜100% increase over the ones grown at 100mTorr. The dielectric constant linearly increases from 220 to 450 with increasing PO2. The observed changes in surface morphology of the films and their properties are shown to be due to the suppression of volatile A-site cation loss.

Giant flexoelectricity in Ba0.6Sr0.4TiO3/Ni0.8Zn0.2Fe2O4 composite

NASA Astrophysics Data System (ADS)

Li, Yong; Shu, Longlong; Huang, Wenbin; Jiang, Xiaoning; Wang, Hong

2014-10-01

Enhanced flexoelectricity in perovskite ceramics and single crystals has been reported before. In this letter, 3-3 ceramic-ceramic Ba0.6Sr0.4TiO3/Ni0.8Zn0.2Fe2O4 composite with a colossal permittivity was employed in the conventional pure bending experiment in order to examine the transverse flexoelectric response. The measured flexoelectric coefficient at 30 Hz is 128 μC/m and varies to 16 μC/m with the frequency increasing from 30 Hz to 120 Hz, mainly due to the inverse correlation between the permittivity and the frequency. This result reveals the permittivity dependence of flexoelectric coefficient in the frequency dispersion materials, suggesting that the giant permittivity composites can be good flexoelectric materials.

Early glottic cancer involving the anterior commissure treated by transoral laser cordectomy.

PubMed

Hoffmann, Caroline; Cornu, Nicolas; Hans, Stéphane; Sadoughi, Babak; Badoual, Cécile; Brasnu, Daniel

2016-08-01

Anterior commissure involvement is considered to be a risk factor for poorer outcomes after transoral laser cordectomy (TLC) for early glottic cancer. The objective of this study was to determine the outcomes and relevance of the tumor-node-metastasis (TNM) classification in a large series of patients with early glottic cancer involving the anterior commissure treated by TLC. The clinical and surgical parameters, as well as follow-up results, of the patients treated consecutively for early-stage glottic squamous cell carcinoma involving the anterior commissure (Tis, T1a, T1b, and T2) by transoral CO2 laser cordectomy in an urban academic medical center from January 2001 to March 2013 were analyzed retrospectively. The main outcomes measures were: 5-year disease free survival (DFS), ultimate local control with laser alone, laryngeal preservation, overall-survival (OS) rates, and disease-specific survival (DSS) rates (Kaplan-Meier). Ninety-six patients treated from January 2001 to March 2013 were included. The 5-year DFS and ultimate local control with laser alone rates were 61.7% and 74.4%, respectively. The laryngeal preservation rate was 93.4%; and the OS and DSS rates were 79.2% and 91.5%, respectively. Postoperative T classification (pT) status was not found to be a significant predictor of recurrences, but was predictive of more severe recurrences requiring other treatments than laser. TLC is an effective treatment for early stage glottic cancer involving the anterior commissure. The TNM classification is a relevant prognosis factor for severe recurrences. 4. Laryngoscope, 126:1817-1822, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Minority carrier lifetime and dark current measurements in mid-wavelength infrared InAs 0.91Sb 0.09 alloy nBn photodetectors

DOE PAGES

Olson, B. V.; Kim, J. K.; Kadlec, E. A.; ...

2015-11-03

Carrier lifetime and dark current measurements are reported for a mid-wavelength infrared InAs 0.91Sb 0.09 alloy nBn photodetector. Minority carrier lifetimes are measured using a non-contact time-resolved microwave technique on unprocessed portions of the nBn wafer and the Auger recombination Bloch function parameter is determined to be |F 1F 2|=0.292. Moreover, the measured lifetimes are also used to calculate the expected diffusion dark current of the nBn devices and are compared with the experimental dark current measured in processed photodetector pixels from the same wafer. As a result, excellent agreement is found between the two, highlighting the important relationship betweenmore » lifetimes and diffusion currents in nBn photodetectors.« less

Copper-related defects in In0.53Ga0.47As grown by liquid-phase epitaxy

NASA Astrophysics Data System (ADS)

Tilly, L. P.; Grimmeiss, H. G.; Hansson, P. O.

1993-01-01

High-purity In0.53Ga0.47As lattice matched to InP was grown by liquid-phase epitaxy and used for the study of Cu-related defects. The samples had a free-electron carrier concentration of n=5.0×1014 cm-3 and an electron mobility of μ77 K=44 000 cm2/V s. A Cu-related acceptor level 25 meV above the valence-band edge was identified using photoluminescence measurements. Comparing the energy position of this shallow acceptor level with the Ev+157.8-meV Cu-acceptor level in GaAs supports the assumption of an internal energy reference level [J. M. Langer, C. Delerue, M. Lannoo, and H. Heinrich, Phys. Rev. B 38, 7723 (1988)] common to GaAs and InxGa1-xAs.

A screening questionnaire for voice problems after treatment of early glottic cancer

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

Gogh, Christine D.L. van; Verdonck-de Leeuw, Irma M.; Boon-Kamma, Brigitte A.

Purpose: After treatment for early glottic cancer, a considerable number of patients end up with voice problems interfering with daily life activities. A 5-item screening questionnaire was designed for detection of voice impairment. The purpose of this study is to assess psychometric properties of this questionnaire in clinical practice. Methods and Materials: The questionnaire was completed by 110 controls without voice complaints and 177 patients after radiotherapy or laser surgery for early glottic cancer. Results: Based on normative data of the controls, a score of 5 or less on at least 1 of the 5 questions was considered to statemore » overall voice impairment. Reliability of the questionnaire proved to be good. Voice impairment was reported in 44% of the patients treated with radiotherapy vs. 29% of the patients treated with endoscopic laser surgery. Conclusions: The questionnaire proved to be a reliable, valid, and feasible method to detect voice impairment in daily life. The questionnaire is easy to fill in, and interpretation is straightforward. It is useful for both radiation oncologists and otorhinolaryngologists in their follow-up of patients treated for early glottic cancer.« less

Intrinsic, Narrow N V Absorption Reveals a Clumpy Outflow in z < 0.4 Radio-Loud Quasars

NASA Astrophysics Data System (ADS)

DeMarcy, Bryan; Serra, Viktoriah; Culliton, Chris; Ganguly, Rajib; Runnoe, Jessie; Charlton, Jane; Eracleous, Michael; Misawa, Toru; Narayanan, Anand

2018-01-01

Quasar outflows are often invoked in models for galaxy evolution to inject energy and momentum into the gas in the host galaxy and influence its star formation history. Thus, the study of quasar outflows is essential for understanding galaxy evolution. N V absorption systems within the associated region (|Δv| ≤ 5000 km s-1) of the quasar are thought to be intrinsic since many show evidence for partial covering of the quasar. A recent archival study of quasar spectra taken with COS/G130M or G160M found 39/181 radio-quiet quasars show intrinsic N V absorption, while none of the 31 radio-loud quasars have N V absorption detected (Culliton et al. 2017). Further investigation of these radio-loud quasars showed a clear bias towards compact morphologies as revealed by FIRST 1.4 GHz imaging and comparatively flat radio spectra. This suggests we are viewing more face-on orientations which prevent us from seeing absorption outflows. The cause for such bias within the HST archive is still unknown; however, it could explain the lack of radio-loud intrinsic N V absorption seen by Culliton et al. (2017). Alternatively, the quasar wind structure may be fundamentally different between radio-loud and radio-quiet objects. We used COS/G130M or G160M to obtain rest-frame UV spectra (1195 Å - 1250 Å) of 14 low-redshift SDSS radio-loud quasars which show lobe-dominated FIRST morphologies to distinguish between these possibilities. Intrinsic N V absorption was detected in 6 of our 14 quasars. This suggests the lack of detections in the archival study was a result of an orientation effect/sampling bias rather than to differences in wind structure between radio-loud and radio-quiet quasars. Interestingly, we find significant overlap in radio core fractions between quasars with and without N V detection. Quasars in our sample with N V detection span a range of core fractions from < 0.01 up to 0.89 while those without detected N V range from 0.04 up to 0.93. A laminar outflow with a

Performance characterization tests of three 0.44-N (0.1 lbf) hydrazine catalytic thrusters

NASA Technical Reports Server (NTRS)

Moynihan, P. I.; Bjorklund, R. A.

1973-01-01

The 0.44-N (0.1-lbf) class of hydrazine catalytic thruster has been evaluated to assess its capability for spacecraft limit-cycle attitude control with thruster pulse durations on the order of 10 milliseconds. Dynamic-environment and limit-cycle simulation tests were performed on three commercially available thruster/valve assemblies, purchased from three different manufacturers. The results indicate that this class of thruster can sustain a launch environment and, when properly temperature-conditioned, can perform limit-cycle operations over the anticipated life span of a multi-year mission. The minimum operating temperature for very short pulse durations was determined for each thruster. Pulsing life tests were then conducted on each thruster under a thermally controlled condition which maintained the catalyst bed at both a nominal 93 C (200 F) and 205 C (400 F). These were the temperatures believed to be slightly below and very near the minimum recommended operating temperature, respectively. The ensuing life tests ranged from 100,000 to 250,000 pulses at these temperatures, as would be required for spacecraft limit-cycle attitude control applications.

Field-induced polarization rotation and phase transitions in 0.70 Pb (M g1 /3N b2 /3 ) O3-0.30 PbTi O3 piezoceramics observed by in situ high-energy x-ray scattering

NASA Astrophysics Data System (ADS)

Hou, Dong; Usher, Tedi-Marie; Fulanovic, Lovro; Vrabelj, Marko; Otonicar, Mojca; Ursic, Hana; Malic, Barbara; Levin, Igor; Jones, Jacob L.

2018-06-01

Changes to the crystal structure of 0.70 Pb (M g1 /3N b2 /3 ) O3-0.30 PbTi O3 (PMN-0.30PT) piezoceramic under application of electric fields at the long-range and local scale are revealed by in situ high-energy x-ray diffraction (XRD) and pair-distribution function (PDF) analyses, respectively. The crystal structure of unpoled samples is identified as monoclinic C m at both the long-range and local scale. In situ XRD results suggest that field-induced polarization rotation and phase transitions occur at specific field strengths. A polarization rotation pathway is proposed based on the Bragg-peak behaviors and the Le Bail fitting results of the in situ XRD patterns. The PDF results show systematic changes to the structures at the local scale, which is in agreement with the changes inferred from the in situ XRD study. More importantly, our results prove that polarization rotation can be detected and determined in a polycrystalline relaxor ferroelectric. This study supports the idea that multiple contributions, specifically ferroelectric-ferroelectric phase transition and polarization rotation, are responsible for the high piezoelectric properties at the morphotropic phase boundary of PMN-x PT piezoceramics.

High Curie temperature and enhanced magnetoelectric properties of the laminated Li0.058(Na0.535K0.48)0.942NbO3/Co0.6 Zn0.4Fe1.7Mn0.3O4 composites

PubMed Central

Yang, Haibo; Zhang, Jintao; Lin, Ying; Wang, Tong

2017-01-01

Laminated magnetoelectric composites of Li0.058(Na0.535K0.48)0.942NbO3 (LKNN)/Co0.6Zn0.4Fe1.7Mn0.3O4 (CZFM) prepared by the conventional solid-state sintering method were investigated for their dielectric, magnetic, and magnetoelectric properties. The microstructure of the laminated composites indicates that the LKNN phase and CZFM phase can coexist in the composites. Compared with the particulate magnetoelectric composites, the laminated composites have better piezoelectric and magnetoelectric properties due to their higher resistances and lower leakage currents. The magnetoelectric behaviors lie on the relative mass ratio of LKNN phase and CZFM phase. The laminated composites possess a high Curie temperature (TC) of 463 °C, and the largest ME coefficient of 285 mV/cm Oe, which is the highest value for the lead-free bulk ceramic magnetoelectric composites so far. PMID:28338006

A Study of Contacts and Back-Surface Reflectors for 0.6eV Ga0.32In0.68As/InAs0.32P0.68 Thermophotovoltaic Monolithically Interconnected Modules

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

Wu, X.; Duda, A.; Carapella, J. J.

1998-12-23

Thermophotovoltaic (TPV) systems have recently rekindled a high level of interest for a number of applications. In order to meet the requirement of low-temperature ({approx}1000 C) TPV systems, 0.6-eV Ga0.32In0.68As/InAs0.32P0.68 TPV monolithically interconnected modules (MIMs) have been developed at the National Renewable energy Laboratory (NREL)[1]. The successful fabrication of Ga0.32In0.68As/InAs0.32P0.68 MIMs depends on developing and optimizing of several key processes. Some results regarding the chemical vapor deposition (CVD)-SiO2 insulating layer, selective chemical etch via sidewall profiles, double-layer antireflection coatings, and metallization via interconnects have previously been given elsewhere [2]. In this paper, we report on the study of contacts andmore » back-surface reflectors. In the first part of this paper, Ti/Pd/Ag and Cr/Pd/Ag contact to n-InAs0.32P0.68and p-Ga0.32In0.68As are investigated. The transfer length method (TLM) was used for measuring of specific contact resistance Rc. The dependence of Rc on different doping levels and different pre-treatment of the two semiconductors will be reported. Also, the adhesion and the thermal stability of Ti/Pd/Ag and Cr/Pd/Ag contacts to n-InAs0.32P0.68and p-Ga0.32In0.68As will be presented. In the second part of this paper, we discuss an optimum back-surface reflector (BSR) that has been developed for 0.6-eV Ga0.32In0.68As/InAs0.32P0.68 TPV MIM devices. The optimum BSR consists of three layers: {approx}1300{angstrom} MgF2 (or {approx}1300{angstrom} CVD SiO2) dielectric layer, {approx}25{angstrom} Ti adhesion layer, and {approx}1500{angstrom} Au reflection layer. This optimum BSR has high reflectance, good adhesion, and excellent thermal stability.« less

Clinical and dosimetric implications of intensity-modulated radiotherapy for early-stage glottic carcinoma

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

Ward, Matthew Christopher, E-mail: wardm3@ccf.org; Pham, Yvonne D.; Kotecha, Rupesh

2016-04-01

Conventional parallel-opposed radiotherapy (PORT) is the established standard technique for early-stage glottic carcinoma. However, case reports have reported the utility of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) with or without image guidance (image-guided radiotherapy, IGRT) in select patients. The proposed advantages of IMRT/VMAT include sparing of the carotid artery, thyroid gland, and the remaining functional larynx, although these benefits remain unclear. The following case study presents a patient with multiple vascular comorbidities treated with VMAT for early-stage glottic carcinoma. A detailed explanation of the corresponding treatment details, dose-volume histogram (DVH) analysis, and a review of the relevant literaturemore » are provided. Conventional PORT remains the standard of care for early-stage glottic carcinoma. IMRT or VMAT may be beneficial for select patients, although great care is necessary to avoid a geographical miss. Clinical data supporting the benefit of CRT are lacking. Therefore, these techniques should be used with caution and only in selected patients.« less

Effect of Ca2+ Ions on Electrical Properties of Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics

NASA Astrophysics Data System (ADS)

Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing

2018-03-01

Ba1-x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm (x = 0.02) to 18 μm (x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.

Effect of Ca2+ Ions on Electrical Properties of Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 Ceramics

NASA Astrophysics Data System (ADS)

Chen, Zhi-hui; Li, Zhi-wei; Ding, Jian-ning; Zhao, Tian-xiang; Qiu, Jian-hua; Zhu, Ke-qian; Xu, Jiu-jun; Zhang, Bing

2018-07-01

Ba1- x Ca x Ti0.90Sn0.10O3-0.05Y2O3 (BCTSY) lead-free piezoceramics with x = 0.02 to 0.10 have been fabricated by solid-state sintering method at 1420°C. The effects of Ca2+ ions on the microstructure and electrical properties of the samples were studied. X-ray diffraction analysis showed that all samples possessed pure perovskite structure with Ca2+ ions diffused into the matrix lattice. The rhombohedral phase and tetragonal phase coexisted in the composition range of 0.02 < x < 0.06. The microstructure of BCTSY ceramic became more homogeneous with addition of Ca2+ ions, and the average grain size of the samples decreased from 97 μm ( x = 0.02) to 18 μm ( x = 0.10). Addition of Ca2+ remarkably improved the piezoelectric properties, enhanced the dielectric frequency dispersion, and increased the Curie temperature of the ceramics. The piezoelectric properties of the ceramics were optimized at x = 0.04 with d 33 and K p values of 579 pC/N and 52.7%, respectively.

SEEDi1.0-3.0 strategies for major noncommunicable diseases in China.

PubMed

Hu, Chun-Song; Tkebuchava, Tengiz

2017-07-01

The purpose of this article is to briefly introduce the status and challenges of major noncommunicable diseases (mNCDs), which include cardiovascular disease, diabetes and cancer, as well as related risk factors, such as environmental pollution, smoking, obesity and sleep disorders. "S-E-E-D" rules or the strategies of "S-E-E-D" intervention (SEEDi) consist of four core healthy elements: sleep, emotion, exercise and diet. The history of SEEDi 1.0-3.0 is also introduced, which includes versions 1.0, 1.5, 2.0 and 3.0 of the program. These guidelines are suitable for prevention and control of mNCDs. Not only the "Healthy China" initiated in China's "13th Five-year Plan," but also the "Healthy World" philosophy needs SEEDi 1.0-3.0 strategies for control of mNCDs.

Ionic conductivity of cold-pressed ceramics from grinding of R0.95M0.05F2.95 solid electrolytes ( R = La, Nd; M = Ca, Sr, Ba) synthesized by reaction in melt

NASA Astrophysics Data System (ADS)

Sorokin, N. I.; Ivanovskaya, N. A.; Sobolev, B. P.

2014-03-01

Cold-pressed ceramics of fluorine-conducting solid electrolytes La1 - y M y F3 - y ( M = Ca, Sr, Ba) and Nd1 - y Ca y F3 - y with y = 0.95 have been synthesized in a melt of RF3 ( R = La, Nd) and MF2 components in a fluorinating atmosphere and ground in a ball mill. The as-prepared ceramics require annealing, during which their porosity decreases and the conductivity is stably increased (by a factor of 250 for the R 1 - y M y F3 - y composition at 293 K). The Nd0.95Ca0.05F2.95 and Nd0.95Ca0.05F2.95 compositions have a maximum ionic conductivity σ(293 K) ˜ 5 × 10-6 Sm/cm. This value is larger (by a factor of about 10) than σ (293 K) for the R 1 - y M y F3 - y ceramics of tysonite phases prepared by mechanochemical synthesis with the cold pressing of reaction products.

Role of Cu During Sintering of Fe0.96Cu0.04 Nanoparticles

NASA Astrophysics Data System (ADS)

Sivaprahasam, D.; Sriramamurthy, A. M.; Bysakh, S.; Sundararajan, G.; Chattopadhyay, K.

2018-04-01

Nanoparticle agglomerates of passivated Fe ( n-Fe) and Fe0.96Cu0.04 ( n-Fe0.96Cu0.04), synthesized through the levitational gas condensation (LGC) process, were compacted and sintered using the conventional powder metallurgy method. The n-Fe0.96Cu0.04 agglomerates produced lower green density than n-Fe, and when compacted under pressure beyond 200 MPa, they underwent lateral cracking during ejection attributed to the presence of a passive oxide layer. Sintering under dynamic hydrogen atmosphere can produce a higher density of compact in n-Fe0.96Cu0.04 in comparison to n-Fe. Both the results of dilatometry and thermogravimetric (TG) measurements of the samples under flowing hydrogen revealed enhancement of the sintering process as soon as the reduction of oxide layers could be accomplished. The shrinkage rate of n-Fe0.96Cu0.04 reached a value three times higher than n-Fe at a low temperature of 723 K (450 °C) during heating. This enhanced shrinkage rate was the manifestation of accumulation of Cu at the surface of the particles. The formation of a thin-surface melted layer enriched with copper during heating to isothermal holding facilitated as a medium of transport for diffusion of the elements. The compacts produced by sintering at 773 K (500 °C), with relative density 82 pct, were found to be unstable and oxidized instantly when exposed to ambient atmosphere. The stable compacts of density more than 92 pct with 300- to 450-nm grain size could only be produced when sintering was carried out at 973 K (700 °C) and beyond. The 0.22 wt pct residual oxygen obtained in the sintered compact is similar to what is used for conventional ferrous powder metallurgy products.

0ħω MEC effect on M1 properties of middle pf-shell nuclei

NASA Astrophysics Data System (ADS)

Nakada, H.; Sebe, T.

1994-09-01

M1 properties of middle pf-shell nuclei are studied within the framework of a large-scale shell-model calculation, by including two-body operators originating from the MEC effect within the 0ħω space. This MEC effect tends to enhance the M1 matrix elements slightly. However, the 0ħω MEC effect does not change the previous results so much, which have shown notable quenching in the magnetic moments of 55Co and 57Ni due to the 0ħω CP effect, while the 0ħω MEC effect should be kept track of in discussing the M1 properties with ⪅ 10% accuracy.

Tunnel-structured Na 0.66[Mn 0.66Ti 0.34]O 2-xF x(x <0.1) cathode for high performance sodium-ion batteries

DOE PAGES

Wang, Qin-Chao; Qiu, Qi-Qi; Xiao, Na; ...

2018-03-13

Sodium-ion batteries (SIBs) are attracting significant research attentions for large-scale energy storage applications. Cathode material is the vital part of SIBs to determine the capacity and cycle performance. Here, a series of F-doped Na 0.66[Mn 0.66Ti 0.34]O 2-xF x (x < 0.1) cathodes with tunnel structure are designed and synthesized aiming to enlarge the sodium diffusion paths. The lattice parameters of unit cell are tuned successfully by adjusting F doping amount. Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 with the optimized stoichiometry exhibits a reversible capacity of 97 mAh g -1 and promising cycle performance (85 mAh g -1 is maintainedmore » at 2C after 1000 cycles) with extremely low voltage polarization. More significantly, Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 exhibits superior low temperature performance, owing to the much enhanced thermodynamics and kinetics benefited from F doping. In conclusion, this strategy may open new opportunities to design advanced intercalation-type cathode materials for sodium ion batteries, especially for low-temperature applications.« less

Tunnel-structured Na 0.66[Mn 0.66Ti 0.34]O 2-xF x(x <0.1) cathode for high performance sodium-ion batteries

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

Wang, Qin-Chao; Qiu, Qi-Qi; Xiao, Na

Sodium-ion batteries (SIBs) are attracting significant research attentions for large-scale energy storage applications. Cathode material is the vital part of SIBs to determine the capacity and cycle performance. Here, a series of F-doped Na 0.66[Mn 0.66Ti 0.34]O 2-xF x (x < 0.1) cathodes with tunnel structure are designed and synthesized aiming to enlarge the sodium diffusion paths. The lattice parameters of unit cell are tuned successfully by adjusting F doping amount. Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 with the optimized stoichiometry exhibits a reversible capacity of 97 mAh g -1 and promising cycle performance (85 mAh g -1 is maintainedmore » at 2C after 1000 cycles) with extremely low voltage polarization. More significantly, Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 exhibits superior low temperature performance, owing to the much enhanced thermodynamics and kinetics benefited from F doping. In conclusion, this strategy may open new opportunities to design advanced intercalation-type cathode materials for sodium ion batteries, especially for low-temperature applications.« less

Electrochemical performance of Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 cermet anodes with functionally graded structures for intermediate-temperature solid oxide fuel cell fueled with syngas

NASA Astrophysics Data System (ADS)

Miyake, Michihiro; Iwami, Makoto; Takeuchi, Mizue; Nishimoto, Shunsuke; Kameshima, Yoshikazu

2018-06-01

The electrochemical performance of layered Ni0.8Cu0.2/Ce0.8Gd0.2O1.9 (GDC) cermet anodes is investigated for intermediate-temperature solid oxide fuel cells (IT-SOFCs) at 600 °C using humidified (3% H2O) model syngas with a molar ratio of H2/CO = 3/2 as the fuel. From the results obtained, the electrochemical performance of the functionally graded multi-layered anodes is found to be superior to the mono-layered anodes. The test cell with a bi-layered anode consisting of 100 mass% Ni0.8Cu0.2/0 mass% GDC (10M/0E) and 70 mass% Ni0.8Cu0.2/30 mass% GDC (7M/3E) exhibits high power density. The test cell with a tri-layered anode consisting of 10M/0E, 7M/3E, and 50 mass% Ni0.8Cu0.2/50 mass% GDC (5M/5E) exhibits an even higher power density, suggesting that 10M/0E and 5M/5E layers contribute to the current collecting part and active part, respectively.

Nanoscale morphology and optical property evolution of Pt nanostructures on GaN (0 0 0 1) by the systematic control of annealing temperature and duration with various Pt thickness

NASA Astrophysics Data System (ADS)

Kunwar, Sundar; Pandey, Puran; Sui, Mao; Zhang, Quanzhen; Li, Ming-Yu; Lee, Jihoon

2017-06-01

By the controlled fabrication of Pt nanostructures, various surface morphology dependent electronic, catalytic and optical properties can be exploited for a wide range of applications. In this paper, the evolution of Pt nanostructures on GaN (0 0 0 1) by the solid-state dewetting of Pt thin films is investigated. Controlling the annealing temperature, time and film thickness allows us to fabricate distinct size, density and configurations of Pt nanostructures. For 10 nm Pt thickness, tiny voids and Pt hillocks up to 550 °C, extensive void expansion and Pt nanostructure evolution between 600 °C-750 °C and finally Pt nanostructures assisted nanoholes penetration on GaN surface above 800 °C are demonstrated. Furthermore, comparatively elongated Pt nanostructures and NHs are resulted with 20 nm Pt thickness and voids growth and connected Pt nanostructure are formed by annealing duration control. The transformation of Pt films to nanostructures is governed by the surface diffusion, Rayleigh instability, Volmer-Weber growth and energy minimization mechanism whereas NHs penetration is commenced by the decomposition of GaN, Pt-Ga alloying and nitrogen desorption at high temperature. In addition, the optical characteristic of Pt nanostructures on GaN (0 0 0 1) by reflectance, photoluminescence (PL) and Raman spectroscopy demonstrate the surface morphology dependent spectral response.

Effect of La0.1Sr0.9Co0.5Mn0.5O3-δ protective coating layer on the performance of La0.6Sr0.4Co0.8Fe0.2O3-δ solid oxide fuel cell cathode

NASA Astrophysics Data System (ADS)

Chou, Ping-Yi; Ciou, Chun-Jing; Lee, Yu-Chen; Hung, I.-Ming

2012-01-01

This study investigates the interface reactivity between La0.1Sr0.9Co0.5Mn0.5O3-δ (LSCM) protective coating layer and Crofer22H interconnects. Additionally, we report the mechanism of Cr poisoning of the La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF) cathode's electrochemical properties. The phase, chemical composition, and element distribution of compounds formed at the LSCM-Crofer22H interface are analyzed by X-ray diffraction (XRD) and electron dispersive microscopy (EDS). After heat treatment at 800 °C for 100 h, the LSCM/Crofer22H sample contains SrCrO3, a compound with good conductivity; the area specific resistance (ASR) for the LSCM/Crofer22H interconnect is approximately 17-40 mΩ cm2. We found that the amount of (Mn0.98Fe0.02)(Mn0.02Fe0.48Cr1.5)O4, Cr3O4, and (Fe,Cr)2O3 oxides form in LSCF/LSCM/Crofer22H is significantly less than that in LSCF/Crofer22H. LSCF conductivity after heating at 800 °C for 100 h, is notably higher when in contact with LSCM/Crofer22H than it is when in contact with Crofer22H. These results demonstrate that the LSCM protective coating prevents LSCF cathode poisoning by Cr evaporated from the Corfer22H interconnects.

Mechanism of carrier injection in (Ni/Au)/p-AlxGa1-xN:Mg(0<=x<0.1) Ohmic contacts

NASA Astrophysics Data System (ADS)

Nikishin, S.; Chary, I.; Borisov, B.; Kuryatkov, V.; Kudryavtsev, Yu.; Asomoza, R.; Karpov, S. Yu.; Holtz, M.

2009-10-01

We report the mechanism of current injection in (Ni/Au)/p-AlxGa1-xN:Mg(0≤x<0.1) Ohmic contacts based on the temperature dependence of hole concentrations (p) and specific contact resistance (ρc). The injection mechanism is found to be thermionic emission in all cases. A model is developed to describe the temperature dependences of p and ρc for Mg concentrations from 1019 to 1020 cm-3. The model takes into account splitting in the valence band structure, hole activation energy, and Schottky barrier height. For GaN (AlGaN) these are found to be 132-140 (135-150) meV and 66-88 (84-93) meV, respectively.

Spin Wave Resonances in La_0.67Ba_0.33MnO_3

NASA Astrophysics Data System (ADS)

Lofland, S. E.; Dominguez, M.; Tyagi, S. D.; Bhagat, S. M.; Kwon, C.; Robson, M. C.; Sharma, R. P.; Ramesh, R.; Venkatesan, T.

1996-03-01

Thin ( ~ 110 nm thick) films of La_0.67Ba_0.33MnO3 (LBMO) were prepared by pulsed laser deposition on LaAlO3 substrates. Some films were grown directly onto LaAlO3 while other films were made by first creating a ~ 80 nm thick buffer layer of SrTiO3 (STO) and then capped with a 20 nm thick layer of STO. X-ray and RBS measurements showed the films to be of high crystalline quality. Film thickness was determined by RBS. Spin wave resonance (SWR) measurements were performed at both 10 and 36 GHz. In both types of films Portis (equally spaced) modes were observed. This indicated a non-uniform magnetization which has a parabolic spatial distribution. However, certain tri-layer films showed Kittel modes which follow the n^2 dependence of the mode number n on the resonance field. From the mode separation and the thickness, we calculate the spin stiffness D(0) to be 47 ± 10 meVÅWith this value of D and the magnetization M, we estimate a spatial variation of the magnetization of ~ 20% for those films which showed Portis modes.

Effect of precursor on epitaxially grown of ZnO thin film on p-GaN/sapphire (0 0 0 1) substrate by hydrothermal technique

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

Sahoo, Trilochan; Ju, Jin-Woo; Kannan, V.

2008-03-04

Single crystalline ZnO thin film on p-GaN/sapphire (0 0 0 1) substrate, using two different precursors by hydrothermal route at a temperature of 90 deg. C were successfully grown. The effect of starting precursor on crystalline nature, surface morphology and optical emission of the films were studied. ZnO thin films were grown in aqueous solution of zinc acetate and zinc nitrate. X-ray diffraction analysis revealed that all the thin films were single crystalline in nature and exhibited wurtzite symmetry and c-axis orientation. The thin films obtained with zinc nitrate had a more pitted rough surface morphology compared to the filmmore » grown in zinc acetate. However the thickness of the films remained unaffected by the nature of the starting precursor. Sharp luminescence peaks were observed from the thin films almost at identical energies but deep level emission was slightly prominent for the thin film grown in zinc nitrate.« less

Broadband 0.25-um Gallium Nitride (GaN) Power Amplifier Designs