Electrochemical K-562 cells sensor based on origami paper device for point-of-care testing.

PubMed

Ge, Shenguang; Zhang, Lina; Zhang, Yan; Liu, Haiyun; Huang, Jiadong; Yan, Mei; Yu, Jinghua

2015-12-01

A low-cost, simple, portable and sensitive paper-based electrochemical sensor was established for the detection of K-562 cell in point-of-care testing. The hybrid material of 3D Au nanoparticles/graphene (3D Au NPs/GN) with high specific surface area and ionic liquid (IL) with widened electrochemical windows improved the good biocompatibility and high conductivity was modified on paper working electrode (PWE) by the classic assembly method and then employed as the sensing surface. IL could not only enhance the electron transfer ability but also provide sensing recognition interface for the conjugation of Con A with cells, with the cell capture efficiency and the sensitivity of biosensor strengthened simultaneously. Concanavalin A (Con A) immobilization matrix was used to capture cells. As proof-of-concept, the paper-based electrochemical sensor for the detection of K-562 cells was developed. With such sandwich-type assay format, K-562 cells as model cells were captured on the surface of Con A/IL/3D AuNPs@GN/PWE. Con A-labeled dendritic PdAg NPs were captured on the surface of K-562 cells. Such dendritic PdAg NPs worked as catalysts promoting the oxidation of thionine (TH) by H2O2 which was released from K-562 cells via the stimulation of phorbol 12-myristate-13-acetate (PMA). Therefore, the current signal response was dependent on the amount of PdAg NPs and the concentration of H2O2, the latter of which corresponded with the releasing amount from cells. So, the detection method of K-562 cell was also developed. Under optimized experimental conditions, 1.5×10(-14) mol of H2O2 releasing from each cell was calculated. The linear range and the detection limit for K-562 cells were determined to be 1.0×10(3)-5.0×10(6) cells/mL and 200 cells/mL, respectively. Such as-prepared sensor showed excellent analytical performance with good fabrication reproducibility, acceptable precision and satisfied accuracy, providing a novel protocol in point-of-care testing of cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Monoaminergic Mechanisms in Epilepsy May Offer Innovative Therapeutic Opportunity for Monoaminergic Multi-Target Drugs.

PubMed

Svob Strac, Dubravka; Pivac, Nela; Smolders, Ilse J; Fogel, Wieslawa A; De Deurwaerdere, Philippe; Di Giovanni, Giuseppe

2016-01-01

A large body of experimental and clinical evidence has strongly suggested that monoamines play an important role in regulating epileptogenesis, seizure susceptibility, convulsions, and comorbid psychiatric disorders commonly seen in people with epilepsy (PWE). However, neither the relative significance of individual monoamines nor their interaction has yet been fully clarified due to the complexity of these neurotransmitter systems. In addition, epilepsy is diverse, with many different seizure types and epilepsy syndromes, and the role played by monoamines may vary from one condition to another. In this review, we will focus on the role of serotonin, dopamine, noradrenaline, histamine, and melatonin in epilepsy. Recent experimental, clinical, and genetic evidence will be reviewed in consideration of the mutual relationship of monoamines with the other putative neurotransmitters. The complexity of epileptic pathogenesis may explain why the currently available drugs, developed according to the classic drug discovery paradigm of "one-molecule-one-target," have turned out to be effective only in a percentage of PWE. Although, no antiepileptic drugs currently target specifically monoaminergic systems, multi-target directed ligands acting on different monoaminergic proteins, present on both neurons and glia cells, may represent a new approach in the management of seizures, and their generation as well as comorbid neuropsychiatric disorders.

Monoaminergic Mechanisms in Epilepsy May Offer Innovative Therapeutic Opportunity for Monoaminergic Multi-Target Drugs

PubMed Central

Svob Strac, Dubravka; Pivac, Nela; Smolders, Ilse J.; Fogel, Wieslawa A.; De Deurwaerdere, Philippe; Di Giovanni, Giuseppe

2016-01-01

A large body of experimental and clinical evidence has strongly suggested that monoamines play an important role in regulating epileptogenesis, seizure susceptibility, convulsions, and comorbid psychiatric disorders commonly seen in people with epilepsy (PWE). However, neither the relative significance of individual monoamines nor their interaction has yet been fully clarified due to the complexity of these neurotransmitter systems. In addition, epilepsy is diverse, with many different seizure types and epilepsy syndromes, and the role played by monoamines may vary from one condition to another. In this review, we will focus on the role of serotonin, dopamine, noradrenaline, histamine, and melatonin in epilepsy. Recent experimental, clinical, and genetic evidence will be reviewed in consideration of the mutual relationship of monoamines with the other putative neurotransmitters. The complexity of epileptic pathogenesis may explain why the currently available drugs, developed according to the classic drug discovery paradigm of “one-molecule-one-target,” have turned out to be effective only in a percentage of PWE. Although, no antiepileptic drugs currently target specifically monoaminergic systems, multi-target directed ligands acting on different monoaminergic proteins, present on both neurons and glia cells, may represent a new approach in the management of seizures, and their generation as well as comorbid neuropsychiatric disorders. PMID:27891070

The psychosocial impact of epilepsy on marriage: A narrative review.

PubMed

Kinariwalla, Neha; Sen, Arjune

2016-10-01

There have been many studies exploring quality of life as well as the impact of epilepsy on the affected individual. However, epilepsy affects more than the patients themselves, and there seems to be a paucity of data regarding the impact of epilepsy beyond the person with epilepsy (PWE). In particular, it is uncertain what the impact of epilepsy on marriage may be. We therefore performed a narrative review to evaluate work measuring the psychosocial effect of epilepsy on marriage. We reviewed the literature on epilepsy and marriage by searching PubMed (Medline) and EMBASE and thoroughly examining relevant bibliographies. Forty-two papers were identified that addressed the issue of the psychosocial effect of epilepsy on marriage. The different approaches used to assess the impact of epilepsy on marriage can be broadly grouped into three categories: assessment of the social effect of living with epilepsy, which includes the marital prospects of PWEs and how changes in martial status associate with seizure frequency; assessment of quality of life (QOL) of PWEs; assessment of the association of social support with the disease burden of epilepsy. Within each of these approaches, different research methods have been employed including questionnaires, qualitative methods, and scales. The studies reviewed indicate that epilepsy has a severe impact on individuals and their families. While many quality-of-life surveys do comment on the marital status of the patient, there is little expansion beyond this. The impact that seizures may have on the partner of a patient with epilepsy is barely addressed. With increasing incidence of epilepsy in older populations, potential changes in the dynamic of a long-term marriage with the development of epilepsy in older age are not known. Similarly, the impact of marriage on concordance with medication or proceeding to, for example, surgical treatment for pharmacoresistant epilepsy has not been studied in detail. We suggest ways in which to address these aspects in order to better deliver holistic care to patients with epilepsy and their partners. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Risk assessment of in-hospital mortality of patients with epilepsy: A large cohort study.

PubMed

Si, Yang; Xiao, Xiaoqiang; Xiang, Shunju; Liu, Jing; Mo, Qianning; Sun, Hongbin

2018-05-09

This study aimed to explore the mortality risks of hospitalized patients with epilepsy (PWE). Our data source was extracted from discharge abstracts in a hospital medical database. Various clinical variables, including demographical characteristics, natural features of epilepsy, and comprehensive set of comorbidities, were screened to investigate the risk. Comorbidities were defined using a validated ICD-10-based classification. The distributions of comorbid conditions and demographics were presented. In-hospital mortality rates of groups with epilepsy and without epilepsy were compared. Logistic regression was applied to explore the important predictors of in-hospital mortality. A cohort of 11,422 PWE (male: 58.5%, mean age: 40.2 years) was recruited for the study. The most common comorbidities were cerebrovascular disease, hypertension, and peripheral vascular disease, which accounted for 23.5%, 18.8%, and 8.0% of the study cohort, respectively. In-hospital mortality rates were 2.9% and 1.1% in the epilepsy and nonepilepsy cohort, respectively. Male patients exhibited an increased risk of death (odds ratio (OR) = 1.2; 95% confidence interval (CI) = 1.0-1.6). Patients aged over 65 years were more likely to die than those below 18 years (OR = 18.2; 95% CI = 8.8-31.0). Patients with comorbidities, including central nervous system (CNS) infections, renal disease, traumatic brain and head injuries, anoxic brain injury, metastatic cancer, pulmonary circulation disorders, encephalopathy, solid tumor without metastasis, cardiac arrhythmias, and diabetes without complication, had a higher risk of in-hospital death than patients without comorbidities (OR = 6.1, 5.2, 5.1, 4.4, 3.7, 2.5, 2.4, 2.0, 1.5, 1.4, respectively; 95% CI = 4.1-9.1, 3.8-7.0, 2.8-9.5, 2.4-8.3, 2.2-6.3, 1.5-4.3, 1.4-4.2, 1.1-3.7, 1.1-2.1, 1.0-1.9, respectively). The in-hospital mortality of PWE increased remarkably with age, and this parameter was predominant in male patients. Central nervous system infection, renal disease, traumatic brain and head injuries, anoxic brain injury, metastatic cancer, pulmonary circulation disorders, encephalopathy, solid tumor without metastasis, cardiac arrhythmias, and diabetes without complication were the most important comorbidities associated with in-hospital death. Copyright © 2018 Elsevier Inc. All rights reserved.

The Study of the plasmaspheric refilling using the data from the ERG, the VAPs, the ground-based magnetometers and the IPE model

NASA Astrophysics Data System (ADS)

Obana, Y.; Maruyama, N.; Masahito, N.; Matsuoka, A.; Teramoto, M.; Nomura, R.; Fujimoto, A.; Tanaka, Y.; Shinohara, M.; Kasahara, Y.; Matsuda, S.; Kumamoto, A.; Tsuchiya, F.; Yoshizumi, M.; Shinohara, I.

2017-12-01

Earth's inner magnetosphere is a complex dynamical region of geo space comprising plasma populations with wide energy ranges, the plasmasphere, ring current, and radiation belts. They form a closely coupled system, thus, the plasmasphere is the lowest energy population in the inner magnetosphere, but the accurate prediction of the evolution of the plasmasphere is critical in understanding the dynamics of the inner magnetosphere, which include even the highest energy population, the radiation belts. In this study, we study plasmaspheric refilling following geomagnetic storms using data from ERG-MGF, ERG-PWE, RBSP-EMFISIS and Ground-based magneto­meters. DC magnetic field data measured by ERG-MGF, RBSP-EMFISIS and ground-based magnetometers provides the frequency of the toroidal mode field line resonances. From this information, the equatorial plasma mass density is estimated by solving the MHD wave equation for suitable models of the magnetic field and the field line density distribution. ERG-PWE and RBSP-EMFISIS provide measurements of wave electric and magnetic field, thus we can estimate the local electron density from the plasma wave spectrograms by identifying narrow-band emission at the upper-hybrid resonance frequency. Furthermore, using Ionosphere Plasmasphere Electrodynamics Model (IPE), we calculate the plasmaspheric refilling rates and evaluate the relative contribution of various mechanisms (heating, neutral particle density, composition and wings, etc.) to the refilling rate.

Epilepsy in India I: Epidemiology and public health

PubMed Central

Amudhan, Senthil; Gururaj, Gopalkrishna; Satishchandra, Parthasarathy

2015-01-01

Of the 70 million persons with epilepsy (PWE) worldwide, nearly 12 million PWE are expected to reside in India; which contributes to nearly one-sixth of the global burden. This paper (first of the two part series) provides an in-depth understanding of the epidemiological aspects of epilepsy in India for developing effective public health prevention and control programs. The overall prevalence (3.0-11.9 per 1,000 population) and incidence (0.2-0.6 per 1,000 population per year) data from recent studies in India on general population are comparable to the rates of high-income countries (HICs) despite marked variations in population characteristics and study methodologies. There is a differential distribution of epilepsy among various sociodemographic and economic groups with higher rates reported for the male gender, rural population, and low socioeconomic status. A changing pattern in the age-specific occurrence of epilepsy with preponderance towards the older age group is noticed due to sociodemographic and epidemiological transition. Neuroinfections, neurocysticercosis (NCC), and neurotrauma along with birth injuries have emerged as major risk factors for secondary epilepsy. Despite its varied etiology (unknown and known), majority of the epilepsy are manageable in nature. This paper emphasizes the need for focused and targeted programs based on a life-course perspective and calls for a stronger public health approach based on equity for prevention, control, and management of epilepsy in India. PMID:26425001

The impact of anxiety, seizure severity, executive dysfunction, subjectively perceived psychological deficits, and depression on social function in patients with epilepsy.

PubMed

Kampf, Christina; Walter, Uwe; Rösche, Johannes

2016-04-01

The impact of anxiety, seizure severity, executive dysfunction, subjectively perceived psychological deficits, and depression on social function in patients with epilepsy (PWE) was analyzed. A brief cognitive screening test (EpiTrack) and an estimation of the last 6 months' cumulative seizure severity (Chalfont seizure severity scale) were performed, and questionnaires on subjectively perceived cognitive deficits (c.I.-Skala), anxiety (State-Trait Anxiety Inventory, STAIX1 and STAIX2), depression (Self Rating Depression Scale, SDS), and social function (Soziale Aktivität Selbstbeurteilungsskala, SASS) were completed. Forty PWE (aged 41.8 years, SD 16; 24 female, 16 male) were analyzed. Thirty-eight point 5 percent had a score signifying depression in the SDS; 20% had a pathological result in at least one of the anxiety scores. The ANOVA revealed that only anxiety as a trait symptom (STAIX2) had a significant influence on social function apart from the other factors (p<0.004). Additionally there was a trend for a significant influence of depressive symptoms (SDS) on social functioning (p=0.093). Symptoms of anxiety impair the social function of patients with epilepsy apart from depression, cognitive function, and seizure severity. They should be taken into account in the treatment of patients with epilepsy. Copyright © 2015 Elsevier Inc. All rights reserved.

Military Review: Airland Battle Future

DTIC Science & Technology

1991-02-01

iciy haronl~pizIilg coti pwe. RieInk fanc , sychoiniation,%-rIit and ham ontion i 11,11C Wil tx~t, i meeani mom d feetig hatdierent ll ila ifrn lsa...NOTES1. LTG John J Tolson Vetnam SWudOs Amnobdirv 1961-1971 (Washwng ment. Aviation brigades will continue recon- ,on. DC J of ft9. 973). 192 GEN John...22d Guards Motorized Infantry Brigade Trento Infantry Division Tobruk Garrison (Major Gen Scobie) Pavia Infantry Division 70th Infantry Division 20th

Index of FAA Office of Aviation Medicine Reports: 1961 through 1993

DTIC Science & Technology

1994-01-01

DOT/F~~J~94 11 Index of FAA Office of Office Of Aviation Medicine Aviation M edicine Reports: Washington, D.C. 20591 1961 through 1993 AD-A275 913 lI...and SubMle 5. Report Dab Index to FAA Office of Aviation Medicine Reports: January 1994 1961 through 1993 6. Pwe ng Organization Code 7. Autho(s) 6...Covered Office of Aviation Medicine Federal Aviation Administration 800 Independence Avenue, S.W. Washington, DC 20591 14. Sponsorg Agency Code 1S. &Su

Associations between religiosity and anxiety, depressive symptoms, and well-being in Korean adults living with epilepsy.

PubMed

Lee, Sang-Ahm; Ryu, Han Uk; Choi, Eun-Ju; Ko, Myung-Ah; Jeon, Ji-Ye; Han, Su-Hyun; Lee, Gha-Hyun; Lee, Moon Kyu; Jo, Kwang-Deog

2017-10-01

Religiosity can be important in the everyday life of persons with epilepsy (PWE). How PWE live with religiosity can be influenced by their cultural background. We determined whether religiosity is associated with anxiety, depressive symptoms, and well-being in Korean adults with epilepsy. This multicenter cross-sectional study was conducted in the outpatient clinics of five university hospitals in Korea. Religiosity was assessed using the five-item Duke University Religion Index (DUREL). The WHO-Five Well-Being Index (WHO-5) and Hospital Anxiety Depression Scale were used. The participants were categorized into three subgroups bounded by the 33rd and 66th percentiles of their DUREL scores. Of a total of 226 participants, 61.1% declared that they had religious affiliation. The median DUREL score was 11 (interquartile ranges 6, 18). All three subscales of the DUREL were significantly related to WHO-5 (p<0.01). Non-organizational religious activities such as prayer and meditation were also inversely related to anxiety (p<0.05) and depressive symptoms (p<0.01). After controlling for confounding variables, anxiety and depressive symptoms were more extensive in the low religiosity subgroup than in the high or no religiosity subgroup (p<0.01) and well-being was higher in the high or low religiosity subgroup than in the no religiosity subgroup (p<0.05). Religiosity is significantly associated with anxiety, depressive symptoms, and well-being in Korean adults with epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.

Methodological difficulties in the conduct of neuroepidemiological studies in low- and middle-income countries.

PubMed

Bharucha, Nadir; Odermatt, Peter; Preux, Pierre-Marie

2014-01-01

The majority of people with epilepsy (PWE) live in low- and middle-income countries (LMICs). However, they remain largely untreated and the bulk of resources are used to treat patients in the developed world. This disparity constitutes a challenge for neuroepidemiological studies on a global scale. In the past, several studies have focused on diverse populations in disparate countries at various periods of time and for particular purposes. The specificity of different contexts and circumstances makes it difficult to analyse PWE as a group either qualitatively or quantitatively. Such methodological limitations are further complicated by a lack of logistical support. There is a lack of interest in conducting studies, which results in inadequate funding and, in addition, there is the considerable challenge of publishing research reports from LMICs in peer-reviewed international journals. This paper focuses on methodological problems related to studies in LMICs and attempts to give the reasons for their limitations using epilepsy as an example. Regional conditions and environmental factors must be given careful consideration in the research design because of the importance of understanding the challenges of living in these environments. There are further limitations to the successful implementation of studies. Existing information on epilepsy is often not readily accessible; there is a lack of census data, and migratory patterns into cities make enumeration and sampling even more challenging. As there is usually no well-developed healthcare system a door-to-door screening process is often the only way to identify those with convulsive epilepsy. The questionnaire and study design should preferably be adapted from standardized protocols, and pre-tested and validated in local conditions. Systematic reviews and meta-analyses of studies in LMICs can provide data on the burden, risk factors, treatment and outcome of epilepsy only if the primary studies used are properly conducted using uniform and comparable methodology. The use of consistent replicable neuroepidemiological methods in primary studies and systematic reviews enable reduction of the treatment gap and better epilepsy care. © 2013 S. Karger AG, Basel.

Electrochemical properties of Sn-based nanopowders synthesized by a pulsed wire evaporation method and effect of binder coating

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

Ha, Jong-Keun; Song, Ju-Seok; Cho, Gyu-Bong

Highlights: • Sn-based nanoparticles are fabricated by using the pulsed wire evaporation method. • The electrodes are prepared by mixing the graphene and coating the surface. • Coating the surface of electrode is used with brushing of simple and facile method. • The electrochemical measurements are performed with galvanostatic experiments. • The coating electrode maintains capacity nearly of 501 mAh g{sup −1} up to 100 cycles. - Abstract: Sn-based nanoparticles are prepared with the O{sub 2} concentrations in chamber of Ar atmosphere (by v/v) by using the pulsed wire evaporation (PWE) method. The prepared electrodes are only Sn-based powder electrode,more » its binder coating electrode and Sn-based powder/graphene nanocomposite electrode. Morphology and structure of the synthesized powders and electrodes are investigated with a field emission scanning electron microscope (FE-SEM) and an X-ray diffraction (XRD) analysis. The electrochemical measurements were performed with galvanostatic cycling experiments using a coin type cell of CR2032 (Ø20, T3.2 mm). The binder coating electrode is superior to others and maintains delithiation capacity nearly of 501 mAh g{sup −1} as 58.3% of first delithiation capacity at 0.2 C-rate up to 100 cycles.« less

Evaluation of the Utilization of Research and Development Results by the Naval Facilities Engineering Command.

DTIC Science & Technology

1980-09-01

Transfer, Vol. 3, No. 2, Spring 1979. Jolly, J. A., J. W . Creighton, and David A. Tansik, The Journal of Technology Transfer, Vol. 4, No. 1, Fall 1-9-79...200 Stovall Strr t , . VA 22332. Released as a Technical Report by: W . M. Tolles Dean of Research Unclassified SECURITY CLASSIFICATION OF ’wee 0469 Rom...SUPPLEMENTARY NOT*5S IN Itv a 110010 (Cewtfn,. -R .evoro old* It 066040pweE OW defo 4V blooS .MSe) Technology Transfer Civil Engineering Laboratory Research and

Review of Maxillary Expansion Appliance Activation Methods: Engineering and Clinical Perspectives

PubMed Central

Romanyk, D. L.; Lagravere, M. O.; Toogood, R. W.; Major, P. W.; Carey, J. P.

2010-01-01

Objective. Review the reported activation methods of maxillary expansion devices for midpalatal suture separation from an engineering perspective and suggest areas of improvement. Materials and Methods. A literature search of Scopus and PubMed was used to determine current expansion methods. A U.S. and Canadian patent database search was also conducted using patent classification and keywords. Any paper presenting a new method of expansion was included. Results. Expansion methods in use, or patented, can be classified as either a screw- or spring-type, magnetic, or shape memory alloy expansion appliance. Conclusions. Each activation method presented unique advantages and disadvantages from both clinical and engineering perspectives. Areas for improvement still remain and are identified in the paper. PMID:20948570

Fabrication of Lab-on-Paper Using Porous Au-Paper Electrode: Application to Tumor Marker Electrochemical Immunoassays.

PubMed

Ge, Shenguang; Zhang, Yan; Yan, Mei; Huang, Jiadong; Yu, Jinghua

2017-01-01

A simple, low-cost, and sensitive electrochemical lab-on-paper assay is developed based on a novel gold nanoparticle modified porous paper working electrode for use in point-of-care testing (POCT). Electrochemical methods are introduced for lab-on-paper based on screen-printed paper electrodes. To further improve specificity, performance, and sensitivity for point-of-care testing, a novel porous Au-paper working electrode (Au-PWE) is designed for lab-on-paper using growth of an interconnected Au nanoparticle (NP) layer on the surface of cellulose fibers in order to enhance the conductivity of the paper sample zone and immobilize the primary antibodies (Ab1). With a sandwich-type immunoassay format, Pd-Au bimetallic nanoparticles possessing peroxidase-like activity are used as a matrix to immobilize secondary antibodies (Ab2) for rapid detection of targets. This lab-on-paper based immunodevice is applied to the diagnosis of a cancer biomarker in clinical serum samples.

Accurate calibration of waveform data measured by the Plasma Wave Experiment on board the ARASE satellite

NASA Astrophysics Data System (ADS)

Kitahara, M.; Katoh, Y.; Hikishima, M.; Kasahara, Y.; Matsuda, S.; Kojima, H.; Ozaki, M.; Yagitani, S.

2017-12-01

The Plasma Wave Experiment (PWE) is installed on board the ARASE satellite to measure the electric field in the frequency range from DC to 10 MHz, and the magnetic field in the frequency range from a few Hz to 100 kHz using two dipole wire-probe antennas (WPT) and three magnetic search coils (MSC), respectively. In particular, the Waveform Capture (WFC), one of the receivers of the PWE, can detect electromagnetic field waveform in the frequency range from a few Hz to 20 kHz. The Software-type Wave Particle Interaction Analyzer (S-WPIA) is installed on the ARASE satellite to measure the energy exchange between plasma waves and particles. Since S-WPIA uses the waveform data measured by WFC to calculate the relative phase angle between the wave magnetic field and velocity of energetic electrons, the high-accuracy is required to calibration of both amplitude and phase of the waveform data. Generally, the calibration procedure of the signal passed through a receiver consists of three steps; the transformation into spectra, the calibration by the transfer function of a receiver, and the inverse transformation of the calibrated spectra into the time domain. Practically, in order to reduce the side robe effect, a raw data is filtered by a window function in the time domain before applying Fourier transform. However, for the case that a first order differential coefficient of the phase transfer function of the system is not negligible, the phase of the window function convoluted into the calibrated spectra is shifted differently at each frequency, resulting in a discontinuity in the time domain of the calibrated waveform data. To eliminate the effect of the phase shift of a window function, we suggest several methods to calibrate a waveform data accurately and carry out simulations assuming simple sinusoidal waves as an input signal and using transfer functions of WPT, MSC, and WFC obtained in pre-flight tests. In consequence, we conclude that the following two methods can reduce an error contaminated through the calibration to less than 0.1 % of amplitude of input waves; (1) a Turkey-type window function with a flat top region of one-third of the window length and (2) modification of the window function for each frequency by referring the estimation of the phase shift due to the first order differential coefficient from the transfer functions.

Research progress on expansive soil cracks under changing environment.

PubMed

Shi, Bei-xiao; Zheng, Cheng-feng; Wu, Jin-kun

2014-01-01

Engineering problems shunned previously rise to the surface gradually with the activities of reforming the natural world in depth, the problem of expansive soil crack under the changing environment becoming a control factor of expansive soil slope stability. The problem of expansive soil crack has gradually become a research hotspot, elaborates the occurrence and development of cracks from the basic properties of expansive soil, and points out the role of controlling the crack of expansive soil strength. We summarize the existing research methods and results of expansive soil crack characteristics. Improving crack measurement and calculation method and researching the crack depth measurement, statistical analysis method, crack depth and surface feature relationship will be the future direction.

A double expansion method for the frequency response of finite-length beams with periodic parameters

NASA Astrophysics Data System (ADS)

Ying, Z. G.; Ni, Y. Q.

2017-03-01

A double expansion method for the frequency response of finite-length beams with periodic distribution parameters is proposed. The vibration response of the beam with spatial periodic parameters under harmonic excitations is studied. The frequency response of the periodic beam is the function of parametric period and then can be expressed by the series with the product of periodic and non-periodic functions. The procedure of the double expansion method includes the following two main steps: first, the frequency response function and periodic parameters are expanded by using identical periodic functions based on the extension of the Floquet-Bloch theorem, and the period-parametric differential equation for the frequency response is converted into a series of linear differential equations with constant coefficients; second, the solutions to the linear differential equations are expanded by using modal functions which satisfy the boundary conditions, and the linear differential equations are converted into algebraic equations according to the Galerkin method. The expansion coefficients are obtained by solving the algebraic equations and then the frequency response function is finally determined. The proposed double expansion method can uncouple the effects of the periodic expansion and modal expansion so that the expansion terms are determined respectively. The modal number considered in the second expansion can be reduced remarkably in comparison with the direct expansion method. The proposed double expansion method can be extended and applied to the other structures with periodic distribution parameters for dynamics analysis. Numerical results on the frequency response of the finite-length periodic beam with various parametric wave numbers and wave amplitude ratios are given to illustrate the effective application of the proposed method and the new frequency response characteristics, including the parameter-excited modal resonance, doubling-peak frequency response and remarkable reduction of the maximum frequency response for certain parametric wave number and wave amplitude. The results have the potential application to structural vibration control.

Non-Invasive Method of Determining Absolute Intracranial Pressure

NASA Technical Reports Server (NTRS)

Yost, William T. (Inventor); Cantrell, John H., Jr. (Inventor); Hargens, Alan E. (Inventor)

2004-01-01

A method is presented for determining absolute intracranial pressure (ICP) in a patient. Skull expansion is monitored while changes in ICP are induced. The patient's blood pressure is measured when skull expansion is approximately zero. The measured blood pressure is indicative of a reference ICP value. Subsequently, the method causes a known change in ICP and measured the change in skull expansion associated therewith. The absolute ICP is a function of the reference ICP value, the known change in ICP and its associated change in skull expansion; and a measured change in skull expansion.

Effects of seizure severity and seizure freedom on the health-related quality of life of an African population of people with epilepsy.

PubMed

Fawale, Michael B; Owolabi, Mayowa O; Ogunniyi, Adesola

2014-03-01

This study aimed at determining the effects of seizure severity and seizure freedom on health-related quality of life (HRQOL) of people with epilepsy (PWE) in the presence of perceived stigma in a sub-Saharan African culture. Health-related quality of life was assessed using QOLIE-31 in 93 consecutive adults (56 males and 37 females) with epilepsy. They were stratified into seizure-free, low-moderate seizure severity, and high seizure severity groups based on the seizure type and the number of seizures in the previous 6months. Other illness variables and sociodemographic variables were also obtained. A 3-item perceived stigma scale was administered. A modified QOLIE-31 (excluding the epilepsy-specific items) was given to 102 age- and sex-matched healthy controls. There was moderate negative correlation between seizure severity and mean total HRQOL score as well as scores on the Seizure Worry (p=.000), Overall Quality of Life (p=.000), and Social Function (p=.001) subscales of QOLIE-31. Overall, the healthy control subjects had a higher mean HRQOL score compared with the PWE put together (71.0+11.1 vs 64.2±13.6, p=.001). However, there was no difference in the mean HRQOL score between the seizure-free individuals and the healthy controls (p=.270). Seizure severity was associated with HRQOL independent of perceived stigma on a multiple regression analysis. This study provides evidence that seizure severity relates to health-related quality of life in an inverse, graded manner and independent of perceived stigma. Seizure-free people with epilepsy can have quality of life comparable with healthy individuals. Copyright © 2013 Elsevier Inc. All rights reserved.

Fatigability and functional performance among older adults with low-normal ankle-brachial index: Cross-sectional findings from the Baltimore Longitudinal Study of Aging.

PubMed

Martinez-Amezcua, Pablo; Matsushita, Kunihiro; Simonsick, Eleanor M; Ferrucci, Luigi; Schrack, Jennifer A

2018-05-01

Peripheral artery disease (PAD) is associated with poor mobility and fatigue, but the relationship between preclinical ankle-brachial index (ABI) and early markers of fatigue and functional decline has not been defined. 570 adults, 50 and older, from the Baltimore Longitudinal Study of Aging (N = 570), with normal values of ABI (1-1.39), were classified into ABI tertiles. Perceived fatigability was assessed after a 5-min, treadmill walk (1.5 mph) using the Borg rating of perceived exertion (RPE, range 6-20). Functional evaluation included the Health, Aging and Body Composition Physical Performance Battery (HABC PPB), time to complete a 400-m corridor walk (LDCW), and VO 2 peak (ml/kg/min). High RPE and poor walking endurance (PWE) were defined as RPE≥10 and taking >5 min for the LDCW, respectively. Differences between tertiles in fatigability and functional measures were tested adjusting for demographics, behavioral characteristics, self-reported fatigue, and medical history. Mean LDCW time and RPE were greater for participants in the lowest tertile compared to those in the highest; mean VO 2 peak and HABC PPB scores were lower, suggesting hierarchical associations between fatigability, functional performance, and ABI (p < 0.05 for all). Odds of PWE were greater for those in the lowest ABI tertile compared to the highest; odds of reporting high RPE were greater for those in the middle tertile. Lower ABI is associated with poorer physical function and increased fatigability, suggesting that early changes in ABI may infer greater risk of functional decline, even among those who may not progress to PAD. Copyright © 2018 Elsevier B.V. All rights reserved.

Blood Pressure and Cerebral White Matter Share Common Genetic Factors in Mexican-Americans

PubMed Central

Kochunov, Peter; Glahn, David C; Lancaster, Jack; Winkler, Anderson; Karlsgodt, Kathrin; Olvera, Rene L; Curran, Joanna E; Carless, Melanie A; Dyer, Thomas D; Almasy, Laura; Duggirala, Ravi; Fox, Peter T; Blangero, John

2010-01-01

Elevated arterial pulse pressure (PP) and blood pressure (BP) can lead to atrophy of cerebral white matter (WM), potentially due to shared genetic factors. We calculated the magnitude of shared genetic variance between BP and fractional anisotropy (FA) of water diffusion, a sensitive measurement of WM integrity in a well-characterized population of Mexican-Americans. The patterns of whole-brain and regional genetic overlap between BP and FA were interpreted in the context the pulse-wave encephalopathy (PWE) theory. We also tested whether regional pattern in genetic pleiotropy is modulated by the phylogeny of WM development. BP and high-resolution (1.7×1.7×3mm, 55 directions) diffusion tensor imaging (DTI) data were analyzed for 332 (202 females; mean age=47.9±13.3years) members of the San Antonio Family Heart Study. Bivariate genetic correlation analysis was used to calculate the genetic overlap between several BP measurements [PP, systolic (SBP) and diastolic (DBP)] and FA (whole-brain and regional values). Intersubject variance in PP and SBP exhibited a significant genetic overlap with variance in whole-brain FA values, sharing 36% and 22% of genetic variance, respectively. Regionally, shared genetic variance was significantly influenced by rates of WM development (r=−.75, p=0.01). The pattern of genetic overlap between BP and WM integrity was generally in-agreement with the PWE theory. Our study provides evidence that a set of pleiotropically acting genetic factors jointly influence phenotypic variation in BP and WM integrity. The magnitude of this overlap appears to be influenced by phylogeny of WM development suggesting a possible role for genotype-by-age interactions. PMID:21135356

Effect of health education on trainee teachers' knowledge, attitudes, and first aid management of epilepsy: An interventional study.

PubMed

Eze, Christian N; Ebuehi, Olufunke M; Brigo, Francesco; Otte, Willem M; Igwe, Stanley C

2015-12-01

High rates of poor knowledge of, and negative attitudes towards people with epilepsy (PWE) are generally found among school teachers. Their first aid epilepsy management skills are poor. It remains unknown if this is different among trainee teachers and whether educational intervention might reduce these rates. We examined the effect of health education on the knowledge, attitudes, and first aid management of epilepsy on trainee teachers in Nigeria. Baseline data and socio-demographic determinants were collected from 226 randomly selected trainee teachers, at the Federal College of Education, Lagos, Nigeria, with self-administered questionnaires. They received a health intervention comprising an hour and half epilepsy lecture followed by a discussion. Baseline knowledge of, and attitudes towards PWE and their first aid epilepsy management skills were compared to post-interventional follow-up data collected twelve weeks later with similar questionnaires. At baseline the majority (61.9%) and largest proportion (44.2%) of respondents had negative attitudes and poor knowledge of epilepsy, respectively. The knowledge of, and attitudes towards epilepsy, and the first aid management skill increased in most respondents, post-intervention. The proportion of respondents with poor knowledge and negative attitudes dropped by 15.5% (p<0.0001) and 16.4% (p<0.0001) respectively. Correct knowledge concomitantly increased by 29.6% (p<0.0001) and good first aid management skills increased by 25.0% (p<0.0001) from baseline. Epilepsy health education could increase trainee teachers' knowledge of, and attitudes towards epilepsy and facilitate correct first aid management. This emphasizes the potential benefit of incorporating an epilepsy tailored intervention programme into teachers' training curricula. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Processes regulating watershed chemical export during snowmelt, fraser experimental forest, Colorado

USGS Publications Warehouse

Stottlemyer, R.

2001-01-01

In the Central Rocky Mountains, snowfall dominates precipitation. Airborne contaminants retained in the snowpack can affect high elevation surface water chemistry during snowmelt. At the Fraser Experimental Forest (FEF), located west of the Continental Divide in Central Colorado, snowmelt dominates the annual hydrograph, and accounts for >95% of annual stream water discharge. During the winters of 1989-1993, we measured precipitation inputs, snowpack water equivalent (SWE) and ion content, and stream water chemistry every 7-10 days along a 3150-3500 m elevation gradient in the subalpine and alpine Lexen Creek watershed. The study objectives were to (1) quantify the distribution of SWE and snowpack chemical content with elevation and aspect, (2) quantify snowmelt rates, temperature of soil, snowpack, and air with elevation and aspect, and (3) use change in upstream-downstream water chemistry during snowmelt to better define alpine and subalpine flowpaths. The SWE increased with elevation (P - 3??C) temperatures throughout winter which resulted in significant snowpack ion loss. By snowpack PWE in mid May, the snowpack had lost almost half the cumulative precipitation H+, NH4+, and SO42- inputs and a third of the NO3- input. Windborne soil particulate inputs late in winter increased snowpack base cation content. Variation in subalpine SWE and snowpack ion content with elevation and aspect, and wind redistribution of snowfall in the alpine resulted in large year-to-year differences in the timing and magnitude of SWE, PWE, and snowpack ion content. The alpine stream water ion concentrations changed little during snowmelt indicating meltwater passed quickly through surface porous soils and was well mixed before entering the stream. Conversely, subalpine stream water chemistry was diluted during snowmelt suggesting much melt water moved to the stream as shallow subsurface lateral flow. Published by Elsevier Science B.V.

Depressive and anxiety disorders in epilepsy: do they differ in their potential to worsen common antiepileptic drug-related adverse events?

PubMed

Kanner, Andres M; Barry, John J; Gilliam, Frank; Hermann, Bruce; Meador, Kimford J

2012-06-01

To compare the effect of anxiety disorders, major depressive episodes (MDEs), and subsyndromic depressive episodes (SSDEs) on antiepileptic drug (AED)-related adverse events (AEs) in persons with epilepsy (PWE). The study included 188 consecutive PWE from five U.S. outpatient epilepsy clinics, all of whom underwent structured interviews (SCID) to identify current and past mood disorders and other current Axis I psychiatric diagnoses according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria. A diagnosis of SSDE was made in patients with total Beck Depression Inventory-II (BDI-II) scores >12 or the Centers of Epidemiologic Studies-Depression (CES-D) > 16 (in the absence of any DSM diagnosis of mood disorder. The presence and severity of AEs was measured with the Adverse Event Profile (AEP). Compared to asymptomatic patients (n = 103), the AEP scores of patients with SSDE (n = 26), MDE only (n = 10), anxiety disorders only (n = 21), or mixed MDE/anxiety disorders (n = 28) were significantly higher, suggesting more severe AED-related AEs. Univariate analyses revealed that having persistent seizures in the last 6 months and taking antidepressants was associated with more severe AEs. Post hoc analyses, however, showed that these differences were accounted for by the presence of a depressive and/or anxiety disorders. Depressive and anxiety disorders worsen AED-related AEs even when presenting as a subsyndromic type. These data suggest that the presence of psychiatric comorbidities must be considered in their interpretation, both in clinical practice and AED drug trials. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

SU-E-J-221: A Novel Expansion Method for MRI Based Target Delineation in Prostate Radiotherapy

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

Ruiz, B; East Carolina University, Greenville, NC; Feng, Y

Purpose: To compare a novel bladder/rectum carveout expansion method on MRI delineated prostate to standard CT and expansion based methods for maintaining prostate coverage while providing superior bladder and rectal sparing. Methods: Ten prostate cases were planned to include four trials: MRI vs CT delineated prostate/proximal seminal vesicles, and each image modality compared to both standard expansions (8mm 3D expansion and 5mm posterior, i.e. ∼8mm) and carveout method expansions (5mm 3D expansion, 4mm posterior for GTV-CTV excluding expansion into bladder/rectum followed by additional 5mm 3D expansion to PTV, i.e. ∼1cm). All trials were planned to total dose 7920 cGy viamore » IMRT. Evaluation and comparison was made using the following criteria: QUANTEC constraints for bladder/rectum including analysis of low dose regions, changes in PTV volume, total control points, and maximum hot spot. Results: ∼8mm MRI expansion consistently produced the most optimal plan with lowest total control points and best bladder/rectum sparing. However, this scheme had the smallest prostate (average 22.9% reduction) and subsequent PTV volume, consistent with prior literature. ∼1cm MRI had an average PTV volume comparable to ∼8mm CT at 3.79% difference. Bladder QUANTEC constraints were on average less for the ∼1cm MRI as compared to the ∼8mm CT and observed as statistically significant with 2.64% reduction in V65. Rectal constraints appeared to follow the same trend. Case-by-case analysis showed variation in rectal V30 with MRI delineated prostate being most favorable regardless of expansion type. ∼1cm MRI and ∼8mm CT had comparable plan quality. Conclusion: MRI delineated prostate with standard expansions had the smallest PTV leading to margins that may be too tight. Bladder/rectum carveout expansion method on MRI delineated prostate was found to be superior to standard CT based methods in terms of bladder and rectal sparing while maintaining prostate coverage. Continued investigation is warranted for further validation.« less

Does query expansion limit our learning? A comparison of social-based expansion to content-based expansion for medical queries on the internet.

PubMed

Pentoney, Christopher; Harwell, Jeff; Leroy, Gondy

2014-01-01

Searching for medical information online is a common activity. While it has been shown that forming good queries is difficult, Google's query suggestion tool, a type of query expansion, aims to facilitate query formation. However, it is unknown how this expansion, which is based on what others searched for, affects the information gathering of the online community. To measure the impact of social-based query expansion, this study compared it with content-based expansion, i.e., what is really in the text. We used 138,906 medical queries from the AOL User Session Collection and expanded them using Google's Autocomplete method (social-based) and the content of the Google Web Corpus (content-based). We evaluated the specificity and ambiguity of the expansion terms for trigram queries. We also looked at the impact on the actual results using domain diversity and expansion edit distance. Results showed that the social-based method provided more precise expansion terms as well as terms that were less ambiguous. Expanded queries do not differ significantly in diversity when expanded using the social-based method (6.72 different domains returned in the first ten results, on average) vs. content-based method (6.73 different domains, on average).

Accounting for Debye sheath expansion for proud Langmuir probes in magnetic confinement fusion plasmas.

PubMed

Tsui, C K; Boedo, J A; Stangeby, P C

2018-01-01

A Child-Langmuir law-based method for accounting for Debye sheath expansion while fitting the current-voltage I-V characteristic of proud Langmuir probes (electrodes that extend into the volume of the plasma) is described. For Langmuir probes of a typical size used in tokamak plasmas, these new estimates of electron temperature and ion saturation current density values decreased by up to 60% compared to methods that did not account for sheath expansion. Changes to the collection area are modeled using the Child-Langmuir law and effective expansion perimeter l p , and the model is thus referred to as the "perimeter sheath expansion method." l p is determined solely from electrode geometry, so the method may be employed without prior measurement of the magnitude of the sheath expansion effects for a given Langmuir probe and can be used for electrodes of different geometries. This method correctly predicts the non-saturating ΔI/ΔV slope for cold, low-density plasmas where sheath-expansion effects are strong, as well as for hot plasmas where ΔI/ΔV ∼ 0, though it is shown that the sheath can still significantly affect the collection area in these hot conditions. The perimeter sheath expansion method has several advantages compared to methods where the non-saturating current is fitted: (1) It is more resilient to scatter in the I-V characteristics observed in turbulent plasmas. (2) It is able to separate the contributions to the ΔI/ΔV slope from sheath expansion to that of the high energy electron tail in high Te conditions. (3) It calculates the change in the collection area due to the Debye sheath for conditions where ΔI/ΔV ∼ 0 and for V = V f .

Accounting for Debye sheath expansion for proud Langmuir probes in magnetic confinement fusion plasmas

NASA Astrophysics Data System (ADS)

Tsui, C. K.; Boedo, J. A.; Stangeby, P. C.; TCV Team

2018-01-01

A Child-Langmuir law-based method for accounting for Debye sheath expansion while fitting the current-voltage I-V characteristic of proud Langmuir probes (electrodes that extend into the volume of the plasma) is described. For Langmuir probes of a typical size used in tokamak plasmas, these new estimates of electron temperature and ion saturation current density values decreased by up to 60% compared to methods that did not account for sheath expansion. Changes to the collection area are modeled using the Child-Langmuir law and effective expansion perimeter lp, and the model is thus referred to as the "perimeter sheath expansion method." lp is determined solely from electrode geometry, so the method may be employed without prior measurement of the magnitude of the sheath expansion effects for a given Langmuir probe and can be used for electrodes of different geometries. This method correctly predicts the non-saturating ΔI/ΔV slope for cold, low-density plasmas where sheath-expansion effects are strong, as well as for hot plasmas where ΔI/ΔV ˜ 0, though it is shown that the sheath can still significantly affect the collection area in these hot conditions. The perimeter sheath expansion method has several advantages compared to methods where the non-saturating current is fitted: (1) It is more resilient to scatter in the I-V characteristics observed in turbulent plasmas. (2) It is able to separate the contributions to the ΔI/ΔV slope from sheath expansion to that of the high energy electron tail in high Te conditions. (3) It calculates the change in the collection area due to the Debye sheath for conditions where ΔI/ΔV ˜ 0 and for V = Vf.

Tunable thermal expansion in framework materials through redox intercalation

PubMed Central

Chen, Jun; Gao, Qilong; Sanson, Andrea; Jiang, Xingxing; Huang, Qingzhen; Carnera, Alberto; Rodriguez, Clara Guglieri; Olivi, Luca; Wang, Lei; Hu, Lei; Lin, Kun; Ren, Yang; Lin, Zheshuai; Wang, Cong; Gu, Lin; Deng, Jinxia; Attfield, J. Paul; Xing, Xianran

2017-01-01

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework-type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion. PMID:28181576

Tunable thermal expansion in framework materials through redox intercalation

NASA Astrophysics Data System (ADS)

Chen, Jun; Gao, Qilong; Sanson, Andrea; Jiang, Xingxing; Huang, Qingzhen; Carnera, Alberto; Rodriguez, Clara Guglieri; Olivi, Luca; Wang, Lei; Hu, Lei; Lin, Kun; Ren, Yang; Lin, Zheshuai; Wang, Cong; Gu, Lin; Deng, Jinxia; Attfield, J. Paul; Xing, Xianran

2017-02-01

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework-type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.

Multipole expansion method for supernova neutrino oscillations

DOE PAGES

Duan, Huaiyu; Shalgar, Shashank

2014-10-31

Here, we demonstrate a multipole expansion method to calculate collective neutrino oscillations in supernovae using the neutrino bulb model. We show that it is much more efficient to solve multi-angle neutrino oscillations in multipole basis than in angle basis. The multipole expansion method also provides interesting insights into multi-angle calculations that were accomplished previously in angle basis.

The impact of antidepressants on seizure frequency and depressive and anxiety disorders of patients with epilepsy: Is it worth investigating?

PubMed

Ribot, Ramses; Ouyang, Bichun; Kanner, Andres M

2017-05-01

Depression and anxiety disorders in patients with epilepsy (PWE) remain under-recognized and under-treated, despite being the most common psychiatric co-morbidities. Selective serotonin re-uptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are considered first-line treatment for primary depression and anxiety disorders. We performed this study to investigate if SSRIs and SNRIs could affect the seizure frequency of PWE and to assess whether such effect is independent of the response of the mood and anxiety disorders to these drugs. This was a retrospective study of 100 consecutive PWE who were started on an SSRI or SNRI for the treatment of a depressive and/or anxiety disorder. Every patient underwent a psychiatric evaluation by one of the investigators using a semi-structured interview who also managed the pharmacologic treatment in all the patients. Patients were excluded if they had a diagnosis of psychogenic non-epileptic seizures or if they had undergone epilepsy surgery or the implant of the vagal nerve stimulator six months before and after the start of the antidepressant therapy. The final analysis was conducted in 84 patients. For each type of seizure, an average and maximal monthly seizure frequency during the six months preceding and following the start of psychotropic drugs was extracted from the medical records. We identified the number of patients whose seizure frequency during treatment with antidepressants: (i) shifted from a <1/month to a ≥1 seizure/month and vice-versa, (ii) increased beyond maximal/monthly baseline frequency, and (iii) patients who developed de-novo generalized tonic-clonic (GTC) seizures. None of the patients with a baseline seizure frequency <1seizure/month went on to have ≥1seizure/month after initiating treatment with antidepressants, had an increase in frequency beyond baseline maximal counts or developed de-novo-GTC seizures. Furthermore, there was no seizure recurrence among patients that had been seizure-free. Among the patients with a baseline seizure frequency ≥1/month, 27.5% had a reduction in seizure frequency to <1/month, which suggested a positive effect of SSRI/SNRI on seizure frequency (p=0.001, McNemar test). Among the patients with a baseline seizure frequency ≥1seizure/month, 48% exhibited a >50% reduction in seizure frequency after the start of treatment with SSRIs or SNRIs. A therapeutic response to SSRIs and SNRIs was found in 73% of patients. The change in seizure frequency was independent of the improvement in psychiatric symptomatology. In this retrospective observational study, SSRIs or SNRIs did not appear to worsen seizure frequency. Also, in patients with frequent seizures, SSRIs and SNRIs may be associated with a possible decrease in seizure frequency. Furthermore, these drugs appear to yield good therapeutic response of psychiatric symptoms independently of seizure frequency. It is pivotal to replicate these data in prospective, double-blind, placebo-controlled trials. Copyright © 2017 Elsevier Inc. All rights reserved.

Implementation of centrifuge testing of expansive soils for pavement design.

DOT National Transportation Integrated Search

2017-03-01

The novel centrifuge-based method for testing of expansive soils from project 5-6048-01 was implemented into : use for the determination of the Potential Vertical Rise (PVR) of roadways that sit on expansive subgrades. The : centrifuge method was mod...

Soliton solutions of the quantum Zakharov-Kuznetsov equation which arises in quantum magneto-plasmas

NASA Astrophysics Data System (ADS)

Sindi, Cevat Teymuri; Manafian, Jalil

2017-02-01

In this paper, we extended the improved tan(φ/2)-expansion method (ITEM) and the generalized G'/G-expansion method (GGEM) proposed by Manafian and Fazli (Opt. Quantum Electron. 48, 413 (2016)) to construct new types of soliton wave solutions of nonlinear partial differential equations (NPDEs). Moreover, we use of the improvement of the Exp-function method (IEFM) proposed by Jahani and Manafian (Eur. Phys. J. Plus 131, 54 (2016)) for obtaining solutions of NPDEs. The merit of the presented three methods is they can find further solutions to the considered problems, including soliton, periodic, kink, kink-singular wave solutions. This paper studies the quantum Zakharov-Kuznetsov (QZK) equation by the aid of the improved tan(φ/2)-expansion method, the generalized G'/G-expansion method and the improvement of the Exp-function method. Moreover, the 1-soliton solution of the modified QZK equation with power law nonlinearity is obtained by the aid of traveling wave hypothesis with the necessary constraints in place for the existence of the soliton. Comparing our new results with Ebadi et al. results (Astrophys. Space Sci. 341, 507 (2012)), namely, G'/G-expansion method, exp-function method, modified F-expansion method, shows that our results give further solutions. Finally, these solutions might play an important role in engineering, physics and applied mathematics fields.

Pressurized heat treatment of glass-ceramic to control thermal expansion

DOEpatents

Kramer, Daniel P.

1985-01-01

A method of producing a glass-ceramic having a specified thermal expansion value is disclosed. The method includes the step of pressurizing the parent glass material to a predetermined pressure during heat treatment so that the glass-ceramic produced has a specified thermal expansion value. Preferably, the glass-ceramic material is isostatically pressed. A method for forming a strong glass-ceramic to metal seal is also disclosed in which the glass-ceramic is fabricated to have a thermal expansion value equal to that of the metal. The determination of the thermal expansion value of a parent glass material placed in a high-temperature environment is also used to determine the pressure in the environment.

49 CFR 180.203 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... atmosphere) and free of components that will adversely react with the cylinder (e.g. chemical stress... pressure. The volumetric expansion test is conducted using the water jacket or direct expansion methods: (1) Water jacket method means a volumetric expansion test to determine a cylinder's total and permanent...

Tunable thermal expansion in framework materials through redox intercalation

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

Chen, Jun; Gao, Qilong; Sanson, Andrea

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present, offering a potential route for control. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF 3, doped with 10% Fe to enable reduction. Themore » small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. As a result, redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.« less

Tunable thermal expansion in framework materials through redox intercalation

DOE PAGES

Chen, Jun; Gao, Qilong; Sanson, Andrea; ...

2017-02-09

Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present, offering a potential route for control. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF 3, doped with 10% Fe to enable reduction. Themore » small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. As a result, redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion.« less

DEFTEST. Defence Technological and Scientific Thesaurus. Volume 2. M - Z

DTIC Science & Technology

1988-05-01

Alanio Elecricci propardse Elsoelo geitiwie I’, pro per",e WPOntadsed i de d51 ga maenerot ; or"mrepI Pd ad es M41gnel Rp hseorrredm Meld.~oh &ew 0"qn...POW mo 0 IiF ~ M~ Mdii -T Pwe 8"swe DT me dpsu PWOPSad ffiff H T COld M Asdm’(illleb) T i ote WaDie Skt Tem msp Theotdad dtudlyFoundry NW MIf -=Wr Pro ...Pr’w s mw dwoe uwm mooning qwy Wad" ia " odil thWa n" Mi bfrtig penwulw mold cmstfg N tsesMWprmtP Pro lop"~ di Rol NTal Copd wOrr Saud angs l w mmitl

A second-order shock-expansion method applicable to bodies of revolution near zero lift

NASA Technical Reports Server (NTRS)

1957-01-01

A second-order shock-expansion method applicable to bodies of revolution is developed by the use of the predictions of the generalized shock-expansion method in combination with characteristics theory. Equations defining the zero-lift pressure distributions and the normal-force and pitching-moment derivatives are derived. Comparisons with experimental results show that the method is applicable at values of the similarity parameter, the ratio of free-stream Mach number to nose fineness ratio, from about 0.4 to 2.

Using a Michelson Interferometer to Measure Coefficient of Thermal Expansion of Copper

ERIC Educational Resources Information Center

Scholl, Ryan; Liby, Bruce W.

2009-01-01

When most materials are heated they expand. This concept is usually demonstrated using some type of mechanical measurement of the linear expansion of a metal rod. We have developed an alternative laboratory method for measuring thermal expansion by using a Michelson interferometer. Using the method presented, interference, interferometry, and the…

Large-Scale Culture and Genetic Modification of Human Natural Killer Cells for Cellular Therapy.

PubMed

Lapteva, Natalia; Parihar, Robin; Rollins, Lisa A; Gee, Adrian P; Rooney, Cliona M

2016-01-01

Recent advances in methods for the ex vivo expansion of human natural killer (NK) cells have facilitated the use of these powerful immune cells in clinical protocols. Further, the ability to genetically modify primary human NK cells following rapid expansion allows targeting and enhancement of their immune function. We have successfully adapted an expansion method for primary NK cells from peripheral blood mononuclear cells or from apheresis products in gas permeable rapid expansion devices (G-Rexes). Here, we describe an optimized protocol for rapid and robust NK cell expansion as well as a method for highly efficient retroviral transduction of these ex vivo expanded cells. These methodologies are good manufacturing practice (GMP) compliant and could be used for clinical-grade product manufacturing.

Modeling laser beam diffraction and propagation by the mode-expansion method.

PubMed

Snyder, James J

2007-08-01

In the mode-expansion method for modeling propagation of a diffracted beam, the beam at the aperture can be expanded as a weighted set of orthogonal modes. The parameters of the expansion modes are chosen to maximize the weighting coefficient of the lowest-order mode. As the beam propagates, its field distribution can be reconstructed from the set of weighting coefficients and the Gouy phase of the lowest-order mode. We have developed a simple procedure to implement the mode-expansion method for propagation through an arbitrary ABCD matrix, and we have demonstrated that it is accurate in comparison with direct calculations of diffraction integrals and much faster.

Series Expansion of Functions with He's Homotopy Perturbation Method

ERIC Educational Resources Information Center

Khattri, Sanjay Kumar

2012-01-01

Finding a series expansion, such as Taylor series, of functions is an important mathematical concept with many applications. Homotopy perturbation method (HPM) is a new, easy to use and effective tool for solving a variety of mathematical problems. In this study, we present how to apply HPM to obtain a series expansion of functions. Consequently,…

A feasibility trial of an Internet-delivered and transdiagnostic cognitive behavioral therapy treatment program for anxiety, depression, and disability among adults with epilepsy.

PubMed

Gandy, Milena; Karin, Eyal; Fogliati, Vincent J; McDonald, Sarah; Titov, Nick; Dear, Blake F

2016-11-01

Anxiety and depression are highly prevalent in people with epilepsy (PWE) and contribute to increased disability. Unfortunately, there are numerous barriers (e.g., cost, distance, and stigma) and service gaps (e.g., lack of services and trained clinicians) that prevent many PWE from accessing traditional face-to-face psychological services. The aim of the present study was to examine the feasibility of a new transdiagnostic Internet-delivered cognitive behavioral therapy (iCBT) program, the Chronic Conditions Course, to simultaneously treat symptoms of anxiety, depression, and disability. A single-group feasibility open trial was employed involving 27 adults with epilepsy. The program comprises five online lessons delivered over 8 weeks and is provided with weekly contact from a mental health professional via e-mail and telephone. High treatment completion rates and levels of satisfaction were reported. Evidence of significant improvements in our primary outcomes (within-group Cohen's d [d]; average [avg.] reductions) of anxiety (d ≥ 1.28; avg. reduction ≥ 54%), depression (d ≥ 1.24; avg. reduction ≥ 54%), epilepsy-specific depression (d ≥ 0.95; avg. reduction ≥ 35%), and disability (d ≥ 0.62; avg. reduction ≥ 33%) were observed at posttreatment, which were sustained at or further improved to 3-month follow-up. On our secondary outcomes there were significant improvements for life satisfaction (d ≥ 0.70; avg. improvement ≥ 26%) but not for perceived cognitive difficulties (d ≥ 0.48; avg. reduction ≥ 15%). Highlighting the potential of the approach, relatively little clinician time was required per participant (mean 80.62 min, standard deviation [SD] 54.78), and the trial involved a broad range of geographically dispersed patients. The findings of the current study support the feasibility and potential of transdiagnostic Internet-delivered treatments for adults with epilepsy. Further large-scale controlled trials are warranted. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Epilepsy and neurocysticercosis in Latin America: a systematic review and meta-analysis.

PubMed

Bruno, Elisa; Bartoloni, Alessandro; Zammarchi, Lorenzo; Strohmeyer, Marianne; Bartalesi, Filippo; Bustos, Javier A; Santivañez, Saul; García, Héctor H; Nicoletti, Alessandra

2013-01-01

The difference in epilepsy burden existing among populations in tropical regions has been attributed to many factors, including the distribution of infectious diseases with neurologic sequels. To define the burden of epilepsy in Latin American Countries (LAC) and to investigate the strength of association with neurocysticercosis (NCC), considered one of the leading causes of epilepsy, we performed a systematic review and meta-analysis of the literature. Studies published until 2012 were selected applying predefined inclusion criteria. Lifetime epilepsy (LTE) prevalence, active epilepsy (AE) prevalence, incidence, mortality, treatment gap (TG) and NCC proportion among people with epilepsy (PWE) were extracted. Median values were obtained for each estimate using random effects meta-analysis. The impact of NCC prevalence on epilepsy estimates was determined using meta-regression models. To assess the association between NCC and epilepsy, a further meta-analysis was performed on case-control studies. The median LTE prevalence was 15.8/1,000 (95% CI 13.5-18.3), the median AE prevalence was 10.7/1,000 (95% CI 8.4-13.2), the median incidence was 138.2/100,000 (95% CI 83.6-206.4), the overall standardized mortality ratio was 1.4 (95% CI 0.01-6.1) and the overall estimated TG was 60.6% (95% CI 45.3-74.9). The median NCC proportion among PWE was 32.3% (95% CI 26.0-39.0). Higher TG and NCC estimates were associated with higher epilepsy prevalence. The association between NCC and epilepsy was significant (p<0.001) with a common odds ratio of 2.8 (95% CI 1.9-4.0). A high burden of epilepsy and of NCC in LAC and a consistent association between these two diseases were pointed out. Furthermore, NCC prevalence and TG were identified as important factors influencing epilepsy prevalence to be considered in prevention and intervention strategies.

Software-type Wave-Particle Interaction Analyzer on board the Arase satellite

NASA Astrophysics Data System (ADS)

Katoh, Yuto; Kojima, Hirotsugu; Hikishima, Mitsuru; Takashima, Takeshi; Asamura, Kazushi; Miyoshi, Yoshizumi; Kasahara, Yoshiya; Kasahara, Satoshi; Mitani, Takefumi; Higashio, Nana; Matsuoka, Ayako; Ozaki, Mitsunori; Yagitani, Satoshi; Yokota, Shoichiro; Matsuda, Shoya; Kitahara, Masahiro; Shinohara, Iku

2018-01-01

We describe the principles of the Wave-Particle Interaction Analyzer (WPIA) and the implementation of the Software-type WPIA (S-WPIA) on the Arase satellite. The WPIA is a new type of instrument for the direct and quantitative measurement of wave-particle interactions. The S-WPIA is installed on the Arase satellite as a software function running on the mission data processor. The S-WPIA on board the Arase satellite uses an electromagnetic field waveform that is measured by the waveform capture receiver of the plasma wave experiment (PWE), and the velocity vectors of electrons detected by the medium-energy particle experiment-electron analyzer (MEP-e), the high-energy electron experiment (HEP), and the extremely high-energy electron experiment (XEP). The prime objective of the S-WPIA is to measure the energy exchange between whistler-mode chorus emissions and energetic electrons in the inner magnetosphere. It is essential for the S-WPIA to synchronize instruments to a relative time accuracy better than the time period of the plasma wave oscillations. Since the typical frequency of chorus emissions in the inner magnetosphere is a few kHz, a relative time accuracy of better than 10 μs is required in order to measure the relative phase angle between the wave and velocity vectors. In the Arase satellite, a dedicated system has been developed to realize the time resolution required for inter-instrument communication. Here, both the time index distributed over all instruments through the satellite system and an S-WPIA clock signal are used, that are distributed from the PWE to the MEP-e, HEP, and XEP through a direct line, for the synchronization of instruments within a relative time accuracy of a few μs. We also estimate the number of particles required to obtain statistically significant results with the S-WPIA and the expected accumulation time by referring to the specifications of the MEP-e and assuming a count rate for each detector.

Design, Synthesis and Evaluation of the Antidepressant and Anticonvulsant Activities of Triazole-Containing Benzo[d]oxazoles.

PubMed

Song, Ming-Xia; Rao, Bao-Qi; Cheng, Bin-Bin; Wu, Yi; Zeng, Hong; Luo, You-Gen; Deng, Xian-Qing

2017-01-01

Epilepsy and depression are two of the common diseases seriously threatening life and health of human. A shared neurobiological substrate led to the bidirectional relationship and high comorbid occurrence of the two disorders. Recently, an increasing number of patients with epilepsy (PWE) require some form of antidepressant medication. However, most of the available antidepressants are inadequate for PWE for some reasons. So, the search for novel and increasingly effective drugs with anticonvulsant and antidepressant activities is necessary. A series of 2-substituted-6-(4H-1,2,4-triazol-4-yl)benzo[d]oxazoles (5a-p) were designed and synthesized. Their anticonvulsant activities were evaluated using maximal electroshock shock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure models in mice. Their antidepressant activities were screened with the forced swimming test (FST). All the compounds showed anti-MES activities in different degree, among which 5g and 5j were the most promising one with ED50 value of 31.7 and 12.7 mg/kg, respectively. What's more, 5g and 5j also exhibited nice anti-scPTZ activities and low neurotoxicity. Interestingly, these compounds also showed good antidepressant activities in FST. And the efficacy of 5g were also confirmed by a tail suspension test and a open field test. The pretreatment of thiosemicarbazide (an inhibitor of γ- aminobutyric acid synthesis enzyme) significantly increased the ED50 of 5g in MES and reversed the reductions in the immobility time of 5g in FST. Triazole-containing benzo[d]oxazole is a good skeleton to develop compounds with both anticonvulsant and antidepressant activities. We have got the compound 5g, which display remarkable antidepressant and anticonvulsant activities, and the GABAergic system was involved in the action mechanism of 5g. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Epilepsy and Neurocysticercosis in Latin America: A Systematic Review and Meta-analysis

PubMed Central

Bruno, Elisa; Bartoloni, Alessandro; Zammarchi, Lorenzo; Strohmeyer, Marianne; Bartalesi, Filippo; Bustos, Javier A.; Santivañez, Saul; García, Héctor H.; Nicoletti, Alessandra

2013-01-01

Background The difference in epilepsy burden existing among populations in tropical regions has been attributed to many factors, including the distribution of infectious diseases with neurologic sequels. To define the burden of epilepsy in Latin American Countries (LAC) and to investigate the strength of association with neurocysticercosis (NCC), considered one of the leading causes of epilepsy, we performed a systematic review and meta-analysis of the literature. Methodology Studies published until 2012 were selected applying predefined inclusion criteria. Lifetime epilepsy (LTE) prevalence, active epilepsy (AE) prevalence, incidence, mortality, treatment gap (TG) and NCC proportion among people with epilepsy (PWE) were extracted. Median values were obtained for each estimate using random effects meta-analysis. The impact of NCC prevalence on epilepsy estimates was determined using meta-regression models. To assess the association between NCC and epilepsy, a further meta-analysis was performed on case-control studies. Principal findings The median LTE prevalence was 15.8/1,000 (95% CI 13.5–18.3), the median AE prevalence was 10.7/1,000 (95% CI 8.4–13.2), the median incidence was 138.2/100,000 (95% CI 83.6–206.4), the overall standardized mortality ratio was 1.4 (95% CI 0.01–6.1) and the overall estimated TG was 60.6% (95% CI 45.3–74.9). The median NCC proportion among PWE was 32.3% (95% CI 26.0–39.0). Higher TG and NCC estimates were associated with higher epilepsy prevalence. The association between NCC and epilepsy was significant (p<0.001) with a common odds ratio of 2.8 (95% CI 1.9–4.0). Significance A high burden of epilepsy and of NCC in LAC and a consistent association between these two diseases were pointed out. Furthermore, NCC prevalence and TG were identified as important factors influencing epilepsy prevalence to be considered in prevention and intervention strategies. PMID:24205415

COMPUTATIONAL METHODS FOR SENSITIVITY AND UNCERTAINTY ANALYSIS FOR ENVIRONMENTAL AND BIOLOGICAL MODELS

EPA Science Inventory

This work introduces a computationally efficient alternative method for uncertainty propagation, the Stochastic Response Surface Method (SRSM). The SRSM approximates uncertainties in model outputs through a series expansion in normal random variables (polynomial chaos expansion)...

Expansion: A Plan for Success.

ERIC Educational Resources Information Center

Callahan, A.P.

This report provides selling brokers' guidelines for the successful expansion of their operations outlining a basic method of preparing an expansion plan. Topic headings are: The Pitfalls of Expansion (The Language of Business, Timely Financial Reporting, Regulatory Agencies of Government, Preoccupation with the Facade of Business, A Business Is a…

Applications of He's semi-inverse method, ITEM and GGM to the Davey-Stewartson equation

NASA Astrophysics Data System (ADS)

Zinati, Reza Farshbaf; Manafian, Jalil

2017-04-01

We investigate the Davey-Stewartson (DS) equation. Travelling wave solutions were found. In this paper, we demonstrate the effectiveness of the analytical methods, namely, He's semi-inverse variational principle method (SIVPM), the improved tan(φ/2)-expansion method (ITEM) and generalized G'/G-expansion method (GGM) for seeking more exact solutions via the DS equation. These methods are direct, concise and simple to implement compared to other existing methods. The exact solutions containing four types solutions have been achieved. The results demonstrate that the aforementioned methods are more efficient than the Ansatz method applied by Mirzazadeh (2015). Abundant exact travelling wave solutions including solitons, kink, periodic and rational solutions have been found by the improved tan(φ/2)-expansion and generalized G'/G-expansion methods. By He's semi-inverse variational principle we have obtained dark and bright soliton wave solutions. Also, the obtained semi-inverse variational principle has profound implications in physical understandings. These solutions might play important role in engineering and physics fields. Moreover, by using Matlab, some graphical simulations were done to see the behavior of these solutions.

Pressurized heat treatment of glass ceramic

DOEpatents

Kramer, D.P.

1984-04-19

A method of producing a glass-ceramic having a specified thermal expansion value is disclosed. The method includes the step of pressurizing the parent glass material to a predetermined pressure during heat treatment so that the glass-ceramic produced has a specified thermal expansion value. Preferably, the glass-ceramic material is isostatically pressed. A method for forming a strong glass-ceramic to metal seal is also disclosed in which the glass-ceramic is fabricated to have a thermal expansion value equal to that of the metal. The determination of the thermal expansion value of a parent glass material placed in a high-temperature environment is also used to determine the pressure in the environment.

Investigation of Key Parameters of Rock Cracking Using the Expansion of Vermiculite Materials

PubMed Central

Ahn, Chi-Hyung; Hu, Jong Wan

2015-01-01

The demand for the development of underground spaces has been sharply increased in lieu of saturated ground spaces because the residents of cities have steadily increased since the 1980s. The traditional widely used excavation methods (i.e., explosion and shield) have caused many problems, such as noise, vibration, extended schedule, and increased costs. The vibration-free (and explosion-free) excavation method has currently attracted attention in the construction site because of the advantage of definitively solving these issues. For such reason, a new excavation method that utilizes the expansion of vermiculite with relatively fewer defects is proposed in this study. In general, vermiculite materials are rapidly expanded in volume when they receive thermal energy. Expansion pressure can be produced by thermal expansion of vermiculite in a steel tube, and measured by laboratory tests. The experimental tests are performed with various influencing parameters in an effort to seek the optimal condition to effectively increase expansion pressure at the same temperature. Then, calibrated expansion pressure is estimated, and compared to each model. After analyzing test results for expansion pressure, it is verified that vermiculite expanded by heat can provide enough internal pressure to break hard rock during tunneling work. PMID:28793610

Investigation of Key Parameters of Rock Cracking Using the Expansion of Vermiculite Materia.

PubMed

Ahn, Chi-Hyung; Hu, Jong Wan

2015-10-12

The demand for the development of underground spaces has been sharply increased in lieu of saturated ground spaces because the residents of cities have steadily increased since the 1980s. The traditional widely used excavation methods ( i.e ., explosion and shield) have caused many problems, such as noise, vibration, extended schedule, and increased costs. The vibration-free (and explosion-free) excavation method has currently attracted attention in the construction site because of the advantage of definitively solving these issues. For such reason, a new excavation method that utilizes the expansion of vermiculite with relatively fewer defects is proposed in this study. In general, vermiculite materials are rapidly expanded in volume when they receive thermal energy. Expansion pressure can be produced by thermal expansion of vermiculite in a steel tube, and measured by laboratory tests. The experimental tests are performed with various influencing parameters in an effort to seek the optimal condition to effectively increase expansion pressure at the same temperature. Then, calibrated expansion pressure is estimated, and compared to each model. After analyzing test results for expansion pressure, it is verified that vermiculite expanded by heat can provide enough internal pressure to break hard rock during tunneling work.

A semi-analytical method of computation of oceanic tidal perturbations in the motion of artificial satellites

NASA Technical Reports Server (NTRS)

Musen, P.

1973-01-01

The method of expansion of the satellite's perturbations, as caused by the oceanic tides, into Fourier series is discussed. The coefficients of the expansion are purely numerical and peculiar to each particular satellite. Such a method is termed as semi-analytical in celestial mechanics. Gaussian form of the differential equations for variation of elements, with the right hand sides averaged over the orbit of the satellite, is convenient to use with the semi-analytical expansion.

Magnetic field effect on the energy levels of an exciton in a GaAs quantum dot: Application for excitonic lasers.

PubMed

Jahan, K Luhluh; Boda, A; Shankar, I V; Raju, Ch Narasimha; Chatterjee, Ashok

2018-03-22

The problem of an exciton trapped in a Gaussian quantum dot (QD) of GaAs is studied in both two and three dimensions in the presence of an external magnetic field using the Ritz variational method, the 1/N expansion method and the shifted 1/N expansion method. The ground state energy and the binding energy of the exciton are obtained as a function of the quantum dot size, confinement strength and the magnetic field and compared with those available in the literature. While the variational method gives the upper bound to the ground state energy, the 1/N expansion method gives the lower bound. The results obtained from the shifted 1/N expansion method are shown to match very well with those obtained from the exact diagonalization technique. The variation of the exciton size and the oscillator strength of the exciton are also studied as a function of the size of the quantum dot. The excited states of the exciton are computed using the shifted 1/N expansion method and it is suggested that a given number of stable excitonic bound states can be realized in a quantum dot by tuning the quantum dot parameters. This can open up the possibility of having quantum dot lasers using excitonic states.

AUTOMATIC GENERATION OF FFT FOR TRANSLATIONS OF MULTIPOLE EXPANSIONS IN SPHERICAL HARMONICS

PubMed Central

Mirkovic, Dragan; Pettitt, B. Montgomery; Johnsson, S. Lennart

2009-01-01

The fast multipole method (FMM) is an efficient algorithm for calculating electrostatic interactions in molecular simulations and a promising alternative to Ewald summation methods. Translation of multipole expansion in spherical harmonics is the most important operation of the fast multipole method and the fast Fourier transform (FFT) acceleration of this operation is among the fastest methods of improving its performance. The technique relies on highly optimized implementation of fast Fourier transform routines for the desired expansion sizes, which need to incorporate the knowledge of symmetries and zero elements in the input arrays. Here a method is presented for automatic generation of such, highly optimized, routines. PMID:19763233

A hybrid-perturbation-Galerkin technique which combines multiple expansions

NASA Technical Reports Server (NTRS)

Geer, James F.; Andersen, Carl M.

1989-01-01

A two-step hybrid perturbation-Galerkin method for the solution of a variety of differential equations type problems is found to give better results when multiple perturbation expansions are employed. The method assumes that there is parameter in the problem formulation and that a perturbation method can be sued to construct one or more expansions in this perturbation coefficient functions multiplied by computed amplitudes. In step one, regular and/or singular perturbation methods are used to determine the perturbation coefficient functions. The results of step one are in the form of one or more expansions each expressed as a sum of perturbation coefficient functions multiplied by a priori known gauge functions. In step two the classical Bubnov-Galerkin method uses the perturbation coefficient functions computed in step one to determine a set of amplitudes which replace and improve upon the gauge functions. The hybrid method has the potential of overcoming some of the drawbacks of the perturbation and Galerkin methods as applied separately, while combining some of their better features. The proposed method is applied, with two perturbation expansions in each case, to a variety of model ordinary differential equations problems including: a family of linear two-boundary-value problems, a nonlinear two-point boundary-value problem, a quantum mechanical eigenvalue problem and a nonlinear free oscillation problem. The results obtained from the hybrid methods are compared with approximate solutions obtained by other methods, and the applicability of the hybrid method to broader problem areas is discussed.

Magnus expansion method for two-level atom interacting with few-cycle pulse

NASA Astrophysics Data System (ADS)

Begzjav, T.; Ben-Benjamin, J. S.; Eleuch, H.; Nessler, R.; Rostovtsev, Y.; Shchedrin, G.

2018-06-01

Using the Magnus expansion to the fourth order, we obtain analytic expressions for the atomic state of a two-level system driven by a laser pulse of arbitrary shape with small pulse area. We also determine the limitation of our obtained formulas due to limited range of convergence of the Magnus series. We compare our method to the recently developed method of Rostovtsev et al. (PRA 2009, 79, 063833) for several detunings. Our analysis shows that our technique based on the Magnus expansion can be used as a complementary method to the one in PRA 2009.

Accompanying coordinate expansion and recurrence relation method using a transfer relation scheme for electron repulsion integrals with high angular momenta and long contractions

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

Hayami, Masao; Seino, Junji; Nakai, Hiromi, E-mail: nakai@waseda.jp

An efficient algorithm for the rapid evaluation of electron repulsion integrals is proposed. The present method, denoted by accompanying coordinate expansion and transferred recurrence relation (ACE-TRR), is constructed using a transfer relation scheme based on the accompanying coordinate expansion and recurrence relation method. Furthermore, the ACE-TRR algorithm is extended for the general-contraction basis sets. Numerical assessments clarify the efficiency of the ACE-TRR method for the systems including heavy elements, whose orbitals have long contractions and high angular momenta, such as f- and g-orbitals.

The modified alternative (G'/G)-expansion method to nonlinear evolution equation: application to the (1+1)-dimensional Drinfel'd-Sokolov-Wilson equation.

PubMed

Akbar, M Ali; Mohd Ali, Norhashidah Hj; Mohyud-Din, Syed Tauseef

2013-01-01

Over the years, (G'/G)-expansion method is employed to generate traveling wave solutions to various wave equations in mathematical physics. In the present paper, the alternative (G'/G)-expansion method has been further modified by introducing the generalized Riccati equation to construct new exact solutions. In order to illustrate the novelty and advantages of this approach, the (1+1)-dimensional Drinfel'd-Sokolov-Wilson (DSW) equation is considered and abundant new exact traveling wave solutions are obtained in a uniform way. These solutions may be imperative and significant for the explanation of some practical physical phenomena. It is shown that the modified alternative (G'/G)-expansion method an efficient and advance mathematical tool for solving nonlinear partial differential equations in mathematical physics.

Apparatus and method for evaporator defrosting

DOEpatents

Mei, Viung C.; Chen, Fang C.; Domitrovic, Ronald E.

2001-01-01

An apparatus and method for warm-liquid defrosting of the evaporator of a refrigeration system. The apparatus includes a first refrigerant expansion device that selectively expands refrigerant for cooling the evaporator, a second refrigerant expansion device that selectively expands the refrigerant after the refrigerant has passed through the evaporator, and a defrosting control for the first refrigerant expansion device and second refrigerant expansion device to selectively defrost the evaporator by causing warm refrigerant to flow through the evaporator. The apparatus is alternately embodied with a first refrigerant bypass and/or a second refrigerant bypass for selectively directing refrigerant to respectively bypass the first refrigerant expansion device and the second refrigerant expansion device, and with the defrosting control connected to the first refrigerant bypass and/or the second refrigerant bypass to selectively activate and deactivate the bypasses depending upon the current cycle of the refrigeration system. The apparatus alternately includes an accumulator for accumulating liquid and/or gaseous refrigerant that is then pumped either to a refrigerant receiver or the first refrigerant expansion device for enhanced evaporator defrosting capability. The inventive method of defrosting an evaporator in a refrigeration system includes the steps of compressing refrigerant in a compressor and cooling the refrigerant in the condenser such that the refrigerant is substantially in liquid form, passing the refrigerant substantially in liquid form through the evaporator, and expanding the refrigerant with a refrigerant expansion device after the refrigerant substantially passes through the evaporator.

Boson expansion based on the extended commutator method in the Tamm-Dancoff representation

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

Pedrocchi, V.G.; Tamura, T.

1983-07-01

Formal aspects of boson expansions in the Tamm-Dancoff representation are investigated in detail. This is carried out in the framework of the extended commutator method by solving in complete generality the coefficient equations, searching for Hermitian as well as non-Hermitian boson expansions. The solutions for the expansion coefficients are obtained in a new form, called the square root realization, which is then applied to carry out an analysis of the relationship between the type of expansion and the boson space in which the expansion is defined. It is shown that this new realization is reduced to various well-known boson theoriesmore » when the boson space is chosen in an appropriate manner. Further discussed, still on the basis of the square root realization, is the equivalence, on a practical level, of a few boson expansion approaches when the Tamm-Dancoff space is truncated to a single quadrupole collective component.« less

Objectively Quantifying Radiation Esophagitis With Novel Computed Tomography–Based Metrics

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

Niedzielski, Joshua S., E-mail: jsniedzielski@mdanderson.org; University of Texas Houston Graduate School of Biomedical Science, Houston, Texas; Yang, Jinzhong

Purpose: To study radiation-induced esophageal expansion as an objective measure of radiation esophagitis in patients with non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy. Methods and Materials: Eighty-five patients had weekly intra-treatment CT imaging and esophagitis scoring according to Common Terminlogy Criteria for Adverse Events 4.0, (24 Grade 0, 45 Grade 2, and 16 Grade 3). Nineteen esophageal expansion metrics based on mean, maximum, spatial length, and volume of expansion were calculated as voxel-based relative volume change, using the Jacobian determinant from deformable image registration between the planning and weekly CTs. An anatomic variability correction method wasmore » validated and applied to these metrics to reduce uncertainty. An analysis of expansion metrics and radiation esophagitis grade was conducted using normal tissue complication probability from univariate logistic regression and Spearman rank for grade 2 and grade 3 esophagitis endpoints, as well as the timing of expansion and esophagitis grade. Metrics' performance in classifying esophagitis was tested with receiver operating characteristic analysis. Results: Expansion increased with esophagitis grade. Thirteen of 19 expansion metrics had receiver operating characteristic area under the curve values >0.80 for both grade 2 and grade 3 esophagitis endpoints, with the highest performance from maximum axial expansion (MaxExp1) and esophageal length with axial expansion ≥30% (LenExp30%) with area under the curve values of 0.93 and 0.91 for grade 2, 0.90 and 0.90 for grade 3 esophagitis, respectively. Conclusions: Esophageal expansion may be a suitable objective measure of esophagitis, particularly maximum axial esophageal expansion and esophageal length with axial expansion ≥30%, with 2.1 Jacobian value and 98.6 mm as the metric value for 50% probability of grade 3 esophagitis. The uncertainty in esophageal Jacobian calculations can be reduced with anatomic correction methods.« less

A new method to generate large order low temperature expansions for discrete spin models

NASA Astrophysics Data System (ADS)

Bhanot, Gyan

1993-03-01

I describe work done in collaboration with Michael Creutz at BNL and Jan Lacki at IAS Princeton. We have developed a method to generate very high order low temperature (weak coupling) expansions for discrete spin systems. For the 3-d and 4-d Ising model, we give results for the low temperature expansion of the average free energy to 50 and 44 excited bonds respectively.

Development of leachate test for delayed ettringite formation potential in cementitious materials

NASA Astrophysics Data System (ADS)

France-Mensah, Jojo

Delayed Ettringite Formation (DEF) has been known to be the cause of expansion and cracking at latter ages in concrete that has been heat cured at temperatures around 70 degree Celsius or above. Currently, the only method available for measuring DEF-related physical expansion in concrete can sometimes take over a year to yield relevant results. A leachate method was proposed as a means of taking advantage of the release and solubility of the adsorbed ions (e.g., calcium, sulfates and aluminates) and alkali ions (e.g., sodium and potassium) in the pore solution after heat curing of the cement paste matrix. These ions, known to contribute to DEF, were leached out of concrete into the leaching solution. The results of the leachate test were correlated to physical expansion data of similar samples from an earlier study. The aim of this research is to apply this knowledge to develop an accelerated leachate test method for identifying the potential for DEF in cementitious materials in a shorter time than the existing method. The objectives of this research are: (1) to identify the ion(s) through leaching that is/are the controlling factors in predicting the rate of expansion and overall expansion of mortar; (2) to identify the ion(s) that is/are responsible for the lag time or age of deleterious expansion through DEF; and (3) to investigate the effect of heat curing on the overall, rate of, and age (time) of expansion.

Method of removing an immiscible lubricant from a refrigeration system and apparatus for same

DOEpatents

Spauschus, Hans O.; Starr, Thomas L.

1999-01-01

A method of separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed.

Solution of a Nonlinear Heat Conduction Equation for a Curvilinear Region with Dirichlet Conditions by the Fast-Expansion Method

NASA Astrophysics Data System (ADS)

Chernyshov, A. D.

2018-05-01

The analytical solution of the nonlinear heat conduction problem for a curvilinear region is obtained with the use of the fast-expansion method together with the method of extension of boundaries and pointwise technique of computing Fourier coefficients.

Numerical investigation of multi-beam laser heterodyne measurement with ultra-precision for linear expansion coefficient of metal based on oscillating mirror modulation

NASA Astrophysics Data System (ADS)

Li, Yan-Chao; Wang, Chun-Hui; Qu, Yang; Gao, Long; Cong, Hai-Fang; Yang, Yan-Ling; Gao, Jie; Wang, Ao-You

2011-01-01

This paper proposes a novel method of multi-beam laser heterodyne measurement for metal linear expansion coefficient. Based on the Doppler effect and heterodyne technology, the information is loaded of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by temperature variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain the value of linear expansion coefficient of metal by the calculation. This novel method is used to simulate measurement for linear expansion coefficient of metal rod under different temperatures by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.4%.

Ultrafast Method for the Analysis of Fluorescence Lifetime Imaging Microscopy Data Based on the Laguerre Expansion Technique

PubMed Central

Jo, Javier A.; Fang, Qiyin; Marcu, Laura

2007-01-01

We report a new deconvolution method for fluorescence lifetime imaging microscopy (FLIM) based on the Laguerre expansion technique. The performance of this method was tested on synthetic and real FLIM images. The following interesting properties of this technique were demonstrated. 1) The fluorescence intensity decay can be estimated simultaneously for all pixels, without a priori assumption of the decay functional form. 2) The computation speed is extremely fast, performing at least two orders of magnitude faster than current algorithms. 3) The estimated maps of Laguerre expansion coefficients provide a new domain for representing FLIM information. 4) The number of images required for the analysis is relatively small, allowing reduction of the acquisition time. These findings indicate that the developed Laguerre expansion technique for FLIM analysis represents a robust and extremely fast deconvolution method that enables practical applications of FLIM in medicine, biology, biochemistry, and chemistry. PMID:19444338

Thermal expansion method for lining tantalum alloy tubing with tungsten

NASA Technical Reports Server (NTRS)

Watson, G. K.; Whittenberger, J. D.; Mattson, W. F.

1973-01-01

A differential-thermal expansion method was developed to line T-111 (tantalum - 8 percent tungsten - 2 percent hafnium) tubing with a tungsten diffusion barrier as part of a fuel element fabrication study for a space power nuclear reactor concept. This method uses a steel mandrel, which has a larger thermal expansion than T-111, to force the tungsten against the inside of the T-111 tube. Variables investigated include lining temperature, initial assembly gas size, and tube length. Linear integrity increased with increasing lining temperature and decreasing gap size. The method should have more general applicability where cylinders must be lined with a thin layer of a second material.

Energy recovery during expansion of compressed gas using power plant low-quality heat sources

DOEpatents

Ochs, Thomas L [Albany, OR; O'Connor, William K [Lebanon, OR

2006-03-07

A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.

Plans and Section Views of DSM Treated Sections

DOT National Transportation Integrated Search

2008-02-01

The effectiveness of Deep Soil Mixing (DSM) treatment method was evaluated in terms of reducing heave movements of underlying expansive soils. Several binder types were used to treat expansive soils and these methods are considered in a laboratory in...

A comparative study of tissue expansion and free parascapular flaps in extensive facial burn scar reconstruction

PubMed Central

Kalra, G S; Bedi, Mitesh; Barala, Vipin Kumar

2017-01-01

Background: Large post burn scars are a very difficult problem to treat. Available methods include skin grafts and tissue expansion. The reconstructive method used should be tailored according to individual patient rather than following a textbook approach in each. Patients and Methods: A retrospective analysis was done of cases with extensive facial burn scars in whom secondary reconstruction was done with either free parascapular flap cover or tissue expansion and flap advancement following facial burn scar excision by a single surgeon (GSK) in Department of Burns, Plastic and reconstructive surgery. Results: A total of 15 patients with free parascapular flap and 15 patients with tissue expansion followed by flap advancement were analyzed in the group. There were no free flap failures, but 2 patients required skin graft at donor site. In patients undergoing tissue expansion, minor complication was noted in 1 patient. Conclusion: Tissue expansion is a useful technique in reconstruction of post burn scars, but has its limitations, especially in patients with extensive burns in head and neck region with limited local tissue availability. Parascapular free flap may provide a good alternative option for reconstruction in such cases. PMID:28804686

Detection of urban expansion in an urban-rural landscape with multitemporal QuickBird images

PubMed Central

Lu, Dengsheng; Hetrick, Scott; Moran, Emilio; Li, Guiying

2011-01-01

Accurately detecting urban expansion with remote sensing techniques is a challenge due to the complexity of urban landscapes. This paper explored methods for detecting urban expansion with multitemporal QuickBird images in Lucas do Rio Verde, Mato Grosso, Brazil. Different techniques, including image differencing, principal component analysis (PCA), and comparison of classified impervious surface images with the matched filtering method, were used to examine urbanization detection. An impervious surface image classified with the hybrid method was used to modify the urbanization detection results. As a comparison, the original multispectral image and segmentation-based mean-spectral images were used during the detection of urbanization. This research indicates that the comparison of classified impervious surface images with matched filtering method provides the best change detection performance, followed by the image differencing method based on segmentation-based mean spectral images. The PCA is not a good method for urban change detection in this study. Shadows and high spectral variation within the impervious surfaces represent major challenges to the detection of urban expansion when high spatial resolution images are used. PMID:21799706

Reliability models: the influence of model specification in generation expansion planning

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

Stremel, J.P.

1982-10-01

This paper is a critical evaluation of reliability methods used for generation expansion planning. It is shown that the methods for treating uncertainty are critical for determining the relative reliability value of expansion alternatives. It is also shown that the specification of the reliability model will not favor all expansion options equally. Consequently, the model is biased. In addition, reliability models should be augmented with an economic value of reliability (such as the cost of emergency procedures or energy not served). Generation expansion evaluations which ignore the economic value of excess reliability can be shown to be inconsistent. The conclusionsmore » are that, in general, a reliability model simplifies generation expansion planning evaluations. However, for a thorough analysis, the expansion options should be reviewed for candidates which may be unduly rejected because of the bias of the reliability model. And this implies that for a consistent formulation in an optimization framework, the reliability model should be replaced with a full economic optimization which includes the costs of emergency procedures and interruptions in the objective function.« less

Method of removing an immiscible lubricant from a refrigeration system and apparatus for same

DOEpatents

Spauschus, H.O.; Starr, T.L.

1999-03-30

A method is described for separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed. 3 figs.

Magnetic Properties of Strongly Correlated Hubbard Model and Quantum Spin-One Ferromagnets with Arbitrary Crystal-Field Potential: Linked Cluster Series Expansion Approach

NASA Astrophysics Data System (ADS)

Pan, Kok-Kwei

We have generalized the linked cluster expansion method to solve more many-body quantum systems, such as quantum spin systems with crystal-field potentials and the Hubbard model. The technique sums up all connected diagrams to a certain order of the perturbative Hamiltonian. The modified multiple-site Wick reduction theorem and the simple tau dependence of the standard basis operators have been used to facilitate the evaluation of the integration procedures in the perturbation expansion. Computational methods are developed to calculate all terms in the series expansion. As a first example, the perturbation series expansion of thermodynamic quantities of the single-band Hubbard model has been obtained using a linked cluster series expansion technique. We have made corrections to all previous results of several papers (up to fourth order). The behaviors of the three dimensional simple cubic and body-centered cubic systems have been discussed from the qualitative analysis of the perturbation series up to fourth order. We have also calculated the sixth-order perturbation series of this model. As a second example, we present the magnetic properties of spin-one Heisenberg model with arbitrary crystal-field potential using a linked cluster series expansion. The calculation of the thermodynamic properties using this method covers the whole range of temperature, in both magnetically ordered and disordered phases. The series for the susceptibility and magnetization have been obtained up to fourth order for this model. The method sums up all perturbation terms to certain order and estimates the result using a well -developed and highly successful extrapolation method (the standard ratio method). The dependence of critical temperature on the crystal-field potential and the magnetization as a function of temperature and crystal-field potential are shown. The critical behaviors at zero temperature are also shown. The range of the crystal-field potential for Ni(2+) compounds is roughly estimated based on this model using known experimental results.

Brillouin corrosion expansion sensors for steel reinforced concrete structures using a fiber optic coil winding method.

PubMed

Zhao, Xuefeng; Gong, Peng; Qiao, Guofu; Lu, Jie; Lv, Xingjun; Ou, Jinping

2011-01-01

In this paper, a novel kind of method to monitor corrosion expansion of steel rebars in steel reinforced concrete structures named fiber optic coil winding method is proposed, discussed and tested. It is based on the fiber optical Brillouin sensing technique. Firstly, a strain calibration experiment is designed and conducted to obtain the strain coefficient of single mode fiber optics. Results have shown that there is a good linear relationship between Brillouin frequency and applied strain. Then, three kinds of novel fiber optical Brillouin corrosion expansion sensors with different fiber optic coil winding packaging schemes are designed. Sensors were embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion, and their performance was studied in a designed electrochemical corrosion acceleration experiment. Experimental results have shown that expansion strain along the fiber optic coil winding area can be detected and measured by the three kinds of sensors with different measurement range during development the corrosion. With the assumption of uniform corrosion, diameters of corrosion steel rebars were obtained using calculated average strains. A maximum expansion strain of 6,738 με was monitored. Furthermore, the uniform corrosion analysis model was established and the evaluation formula to evaluate mass loss rate of steel rebar under a given corrosion rust expansion rate was derived. The research has shown that three kinds of Brillouin sensors can be used to monitor the steel rebar corrosion expansion of reinforced concrete structures with good sensitivity, accuracy and monitoring range, and can be applied to monitor different levels of corrosion. By means of this kind of monitoring technique, quantitative corrosion expansion monitoring can be carried out, with the virtues of long durability, real-time monitoring and quasi-distribution monitoring.

Brillouin Corrosion Expansion Sensors for Steel Reinforced Concrete Structures Using a Fiber Optic Coil Winding Method

PubMed Central

Zhao, Xuefeng; Gong, Peng; Qiao, Guofu; Lu, Jie; Lv, Xingjun; Ou, Jinping

2011-01-01

In this paper, a novel kind of method to monitor corrosion expansion of steel rebars in steel reinforced concrete structures named fiber optic coil winding method is proposed, discussed and tested. It is based on the fiber optical Brillouin sensing technique. Firstly, a strain calibration experiment is designed and conducted to obtain the strain coefficient of single mode fiber optics. Results have shown that there is a good linear relationship between Brillouin frequency and applied strain. Then, three kinds of novel fiber optical Brillouin corrosion expansion sensors with different fiber optic coil winding packaging schemes are designed. Sensors were embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion, and their performance was studied in a designed electrochemical corrosion acceleration experiment. Experimental results have shown that expansion strain along the fiber optic coil winding area can be detected and measured by the three kinds of sensors with different measurement range during development the corrosion. With the assumption of uniform corrosion, diameters of corrosion steel rebars were obtained using calculated average strains. A maximum expansion strain of 6,738 με was monitored. Furthermore, the uniform corrosion analysis model was established and the evaluation formula to evaluate mass loss rate of steel rebar under a given corrosion rust expansion rate was derived. The research has shown that three kinds of Brillouin sensors can be used to monitor the steel rebar corrosion expansion of reinforced concrete structures with good sensitivity, accuracy and monitoring range, and can be applied to monitor different levels of corrosion. By means of this kind of monitoring technique, quantitative corrosion expansion monitoring can be carried out, with the virtues of long durability, real-time monitoring and quasi-distribution monitoring. PMID:22346672

On WKB expansions for Alfven waves in the solar wind

NASA Technical Reports Server (NTRS)

Hollweg, Joseph V.

1990-01-01

The WKB expansion for 'toroidal' Alfven waves in solar wind, which is described by equations of Heinemann and Olbert (1980), is examined. In this case, the multiple scales method (Nayfeh, 1981) is used to obtain a uniform expansion. It is shown that the WKB expansion used by Belcher (1971) and Hollweg (1973) for Alfven waves in the solar wind is nonuniformly convergent.

On WKB expansions for Alfven waves in the solar wind

NASA Astrophysics Data System (ADS)

Hollweg, Joseph V.

1990-09-01

The WKB expansion for 'toroidal' Alfven waves in solar wind, which is described by equations of Heinemann and Olbert (1980), is examined. In this case, the multiple scales method (Nayfeh, 1981) is used to obtain a uniform expansion. It is shown that the WKB expansion used by Belcher (1971) and Hollweg (1973) for Alfven waves in the solar wind is nonuniformly convergent.

Method of fabricating composite structures

NASA Technical Reports Server (NTRS)

Sigur, W. A. (Inventor)

1990-01-01

A method of fabricating structures formed from composite materials by positioning the structure about a high coefficient of thermal expansion material, wrapping a graphite fiber overwrap about the structure, and thereafter heating the assembly to expand the high coefficient of thermal expansion material to forcibly compress the composite structure against the restraint provided by the graphite overwrap. The high coefficient of thermal expansion material is disposed about a mandrel with a release system therebetween, and with a release system between the material having the high coefficient of thermal expansion and the composite material, and between the graphite fibers and the composite structure. The heating may occur by inducing heat into the assembly by a magnetic field created by coils disposed about the assembly through which alternating current flows. The method permits structures to be formed without the use of an autoclave.

Method of fabricating composite structures

NASA Technical Reports Server (NTRS)

Sigur, Wanda A. (Inventor)

1992-01-01

A method of fabricating structures formed from composite materials by positioning the structure about a high coefficient of thermal expansion material, wrapping a graphite fiber overwrap about the structure, and thereafter heating the assembly to expand the high coefficient of thermal expansion material to forcibly compress the composite structure against the restraint provided by the graphite overwrap. The high coefficient of thermal expansion material is disposed about a mandrel with a release system therebetween, and with a release system between the material having the high coefficient of thermal expansion and the composite material, and between the graphite fibers and the composite structure. The heating may occur by inducing heat into the assembly by a magnetic field created by coils disposed about the assembly through which alternating current flows. The method permits structures to be formed without the use of an autoclave.

A NOVEL ENVIRONMENT FRIENDLY METHOD FOR EXPANSION AND MOLDING OF POLYMERIC FOAM

EPA Science Inventory

The objective of the project is to develop an environment friendly, novel and efficient alternative process for expansion and molding of polymeric foam. Spherical, expandable polymer beads are prepared from liquid monomer suspended in an aqueous medium, containing an expansion...

Investigation of advanced UQ for CRUD prediction with VIPRE.

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

Eldred, Michael Scott

2011-09-01

This document summarizes the results from a level 3 milestone study within the CASL VUQ effort. It demonstrates the application of 'advanced UQ,' in particular dimension-adaptive p-refinement for polynomial chaos and stochastic collocation. The study calculates statistics for several quantities of interest that are indicators for the formation of CRUD (Chalk River unidentified deposit), which can lead to CIPS (CRUD induced power shift). Stochastic expansion methods are attractive methods for uncertainty quantification due to their fast convergence properties. For smooth functions (i.e., analytic, infinitely-differentiable) in L{sup 2} (i.e., possessing finite variance), exponential convergence rates can be obtained under order refinementmore » for integrated statistical quantities of interest such as mean, variance, and probability. Two stochastic expansion methods are of interest: nonintrusive polynomial chaos expansion (PCE), which computes coefficients for a known basis of multivariate orthogonal polynomials, and stochastic collocation (SC), which forms multivariate interpolation polynomials for known coefficients. Within the DAKOTA project, recent research in stochastic expansion methods has focused on automated polynomial order refinement ('p-refinement') of expansions to support scalability to higher dimensional random input spaces [4, 3]. By preferentially refining only in the most important dimensions of the input space, the applicability of these methods can be extended from O(10{sup 0})-O(10{sup 1}) random variables to O(10{sup 2}) and beyond, depending on the degree of anisotropy (i.e., the extent to which randominput variables have differing degrees of influence on the statistical quantities of interest (QOIs)). Thus, the purpose of this study is to investigate the application of these adaptive stochastic expansion methods to the analysis of CRUD using the VIPRE simulation tools for two different plant models of differing random dimension, anisotropy, and smoothness.« less

Combining continuous near-road monitoring and inverse modeling to isolate the effect of highway expansion on a school in Las Vegas

EPA Science Inventory

The impact of a highway expansion on a school adjacent to the highway is investigated with a novel method called the Sustained Wind Incidence Method (SWIM). SWIM falls under the broad group of environmental forensics methods where measured concentration data are used to identify ...

Identifying and reducing error in cluster-expansion approximations of protein energies.

PubMed

Hahn, Seungsoo; Ashenberg, Orr; Grigoryan, Gevorg; Keating, Amy E

2010-12-01

Protein design involves searching a vast space for sequences that are compatible with a defined structure. This can pose significant computational challenges. Cluster expansion is a technique that can accelerate the evaluation of protein energies by generating a simple functional relationship between sequence and energy. The method consists of several steps. First, for a given protein structure, a training set of sequences with known energies is generated. Next, this training set is used to expand energy as a function of clusters consisting of single residues, residue pairs, and higher order terms, if required. The accuracy of the sequence-based expansion is monitored and improved using cross-validation testing and iterative inclusion of additional clusters. As a trade-off for evaluation speed, the cluster-expansion approximation causes prediction errors, which can be reduced by including more training sequences, including higher order terms in the expansion, and/or reducing the sequence space described by the cluster expansion. This article analyzes the sources of error and introduces a method whereby accuracy can be improved by judiciously reducing the described sequence space. The method is applied to describe the sequence-stability relationship for several protein structures: coiled-coil dimers and trimers, a PDZ domain, and T4 lysozyme as examples with computationally derived energies, and SH3 domains in amphiphysin-1 and endophilin-1 as examples where the expanded pseudo-energies are obtained from experiments. Our open-source software package Cluster Expansion Version 1.0 allows users to expand their own energy function of interest and thereby apply cluster expansion to custom problems in protein design. © 2010 Wiley Periodicals, Inc.

49 CFR 180.203 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (e.g. chemical stress corrosion). Condemn means a determination that a cylinder is unserviceable for... using the water jacket or direct expansion methods: (1) Water jacket method means a volumetric expansion... volume of water the cylinder externally displaces at test pressure and the volume of water the cylinder...

Many-body expansion of the Fock matrix in the fragment molecular orbital method

NASA Astrophysics Data System (ADS)

Fedorov, Dmitri G.; Kitaura, Kazuo

2017-09-01

A many-body expansion of the Fock matrix in the fragment molecular orbital method is derived up to three-body terms for restricted Hartree-Fock and density functional theory in the atomic orbital basis and compared to the expansion in the basis of fragment molecular orbitals (MOs). The physical nature of many-body corrections is revealed in terms of charge transfer terms. An improvement of the fragment MO expansion is proposed by adding exchange to the embedding. The accuracy of all developed methods is demonstrated in comparison to unfragmented results for polyalanines, a water cluster, Trp-cage (PDB: 1L2Y) and crambin (PDB: 1CRN) proteins, a zeolite cluster, a Si nano-wire, and a boron nitride ribbon. The physical nature of metallicity is discussed, and it is shown what kinds of metallic systems can be treated by fragment-based methods. The density of states is calculated for a fully closed and a partially open nano-ring of boron nitride with a diameter of 105 nm.

Characterization of demographic expansions from pairwise comparisons of linked microsatellite haplotypes.

PubMed

Navascués, Miguel; Hardy, Olivier J; Burgarella, Concetta

2009-03-01

This work extends the methods of demographic inference based on the distribution of pairwise genetic differences between individuals (mismatch distribution) to the case of linked microsatellite data. Population genetics theory describes the distribution of mutations among a sample of genes under different demographic scenarios. However, the actual number of mutations can rarely be deduced from DNA polymorphisms. The inclusion of mutation models in theoretical predictions can improve the performance of statistical methods. We have developed a maximum-pseudolikelihood estimator for the parameters that characterize a demographic expansion for a series of linked loci evolving under a stepwise mutation model. Those loci would correspond to DNA polymorphisms of linked microsatellites (such as those found on the Y chromosome or the chloroplast genome). The proposed method was evaluated with simulated data sets and with a data set of chloroplast microsatellites that showed signal for demographic expansion in a previous study. The results show that inclusion of a mutational model in the analysis improves the estimates of the age of expansion in the case of older expansions.

Fourier series expansion for nonlinear Hamiltonian oscillators.

PubMed

Méndez, Vicenç; Sans, Cristina; Campos, Daniel; Llopis, Isaac

2010-06-01

The problem of nonlinear Hamiltonian oscillators is one of the classical questions in physics. When an analytic solution is not possible, one can resort to obtaining a numerical solution or using perturbation theory around the linear problem. We apply the Fourier series expansion to find approximate solutions to the oscillator position as a function of time as well as the period-amplitude relationship. We compare our results with other recent approaches such as variational methods or heuristic approximations, in particular the Ren-He's method. Based on its application to the Duffing oscillator, the nonlinear pendulum and the eardrum equation, it is shown that the Fourier series expansion method is the most accurate.

Exact traveling wave solutions of the KP-BBM equation by using the new approach of generalized (G'/G)-expansion method.

PubMed

Alam, Md Nur; Akbar, M Ali

2013-01-01

The new approach of the generalized (G'/G)-expansion method is an effective and powerful mathematical tool in finding exact traveling wave solutions of nonlinear evolution equations (NLEEs) in science, engineering and mathematical physics. In this article, the new approach of the generalized (G'/G)-expansion method is applied to construct traveling wave solutions of the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation. The solutions are expressed in terms of the hyperbolic functions, the trigonometric functions and the rational functions. By means of this scheme, we found some new traveling wave solutions of the above mentioned equation.

Density measurements in low pressure, weakly magnetized, RF plasmas: experimental verification of the sheath expansion effect

NASA Astrophysics Data System (ADS)

Zhang, Yunchao; Charles, Christine; Boswell, Roderick W.

2017-07-01

This experimental study shows the validity of Sheridan's method in determining plasma density in low pressure, weakly magnetized, RF plasmas using ion saturation current data measured by a planar Langmuir probe. The ion density derived from Sheridan's method which takes into account the sheath expansion around the negatively biased probe tip, presents a good consistency with the electron density measured by a cylindrical RF-compensated Langmuir probe using the Druyvesteyn theory. The ion density obtained from the simplified method which neglects the sheath expansion effect, overestimates the true density magnitude, e.g., by a factor of 3 to 12 for the present experiment.

Systems and methods for determining strength of cylindrical structures by internal pressure loading

DOEpatents

DeTeresa, Steven John; Groves, Scott Eric; Sanchez, Roberto Joseph; Andrade, William Andrew

2015-08-04

In one embodiment, an apparatus, includes: a mandrel; an expansion cylinder, comprising: opposite first and second ends; an inner circumferential surface extending between the ends and characterized by an inner diameter, the inner circumferential surface defining a hollow cavity; an outer circumferential surface extending between the ends and characterized by an outer diameter that is greater than the inner diameter; and a plurality of slots extending from the inner circumferential surface to the outer circumferential surface and latitudinally oriented between the ends; and one or more base plates configured to engage one of the ends of the expansion cylinder. In another embodiment, a method includes: arranging an expansion cylinder inside a test cylinder; arranging a mandrel inside the expansion cylinder; applying a force to the mandrel for exerting a radial force on the expansion cylinder; and detecting one or more indicia of structural failure of the test cylinder.

Preparation of Shrinkage Compensating Concrete with HCSA Expansive Agent

NASA Astrophysics Data System (ADS)

Li, Changcheng; Jia, Fujia

2017-10-01

Shrinkage compensating concrete (SCC) has become one of the best effective methods of preventing and reducing concrete cracking. SCC is prepared by HCSA high performance expansive agent for concrete which restrained expansion rate is optimized by 0.057%. Slump, compressive strength, restrained expansion rate and cracking resistance test were carried out on SCC. The results show that the initial slump of fresh SCC was about 220mm-230mm, while slump after 2 hours was 180mm-200mm. The restrained expansion rate of SCC increased with the mixing amount of expansive agent. After cured in water for 14 days, the restrained expansion rate of C35 and C40 SCC were 0.020%-0.032%. With the dosage of expansive agent increasing, restrained expansion rate of SCC increased, maximum compressive stress and cracking stress improved, cracking temperature fell, thus cracking resistance got effectively improvement.

Traveling wave solutions of the Boussinesq equation via the new approach of generalized (G'/G)-expansion method.

PubMed

Alam, Md Nur; Akbar, M Ali; Roshid, Harun-Or-

2014-01-01

Exact solutions of nonlinear evolution equations (NLEEs) play a vital role to reveal the internal mechanism of complex physical phenomena. In this work, the exact traveling wave solutions of the Boussinesq equation is studied by using the new generalized (G'/G)-expansion method. Abundant traveling wave solutions with arbitrary parameters are successfully obtained by this method and the wave solutions are expressed in terms of the hyperbolic, trigonometric, and rational functions. It is shown that the new approach of generalized (G'/G)-expansion method is a powerful and concise mathematical tool for solving nonlinear partial differential equations in mathematical physics and engineering. 05.45.Yv, 02.30.Jr, 02.30.Ik.

Engineered high expansion glass-ceramics having near linear thermal strain and methods thereof

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

Dai, Steve Xunhu; Rodriguez, Mark A.; Lyon, Nathanael L.

The present invention relates to glass-ceramic compositions, as well as methods for forming such composition. In particular, the compositions include various polymorphs of silica that provide beneficial thermal expansion characteristics (e.g., a near linear thermal strain). Also described are methods of forming such compositions, as well as connectors including hermetic seals containing such compositions.

An analysis of quality of life (QOL) in patients with epilepsy and comorbid psychogenic nonepileptic seizures (PNES) after vagus nerve stimulation (VNS).

PubMed

Vivas, Andrew C; Reitano, Christian J; Waseem, Hena; Benbadis, Selim R; Vale, Fernando L

2017-08-01

Patients with epilepsy (PWE) may suffer from comorbid psychogenic nonepileptic seizures (PNES). The efficacy of vagus nerve stimulation (VNS) in the treatment of epilepsy and depression is established, however the impact on PNES is unknown. Since many patients with PNES have comorbid depression, we explored the impact on quality of life (QOL) that VNS has on PWE and PNES. The video electroencephalogram (vEEG) of all patients who underwent VNS at our institution was reviewed. Patients diagnosed with both psychogenic seizures and epileptic seizures on their vEEG were included in this study. These patients were contacted, and given a QOLIE-31 survey to assess their quality of life after VNS. Patients also completed a separate survey created by our group to categorize the quartile of their improvement. Pre-operative psychiatric disease was retrospectively reviewed. From a period of 2001 to 2016, 518 patients underwent placement of VNS for drug resistant epilepsy (DRE) at our institution. In total, 16 patients were diagnosed with both epilepsy and PNES. 11/16 patients responded to our questionnaire and survey. 9 out of 11 patients felt that their epileptic seizures had improved after VNS, while 7 of the 11 patients felt that their psychogenic episodes had improved. 2(28.6%), 1 (14.3%), and 4 (57.1%) of participants said their PNES improved by 25-50%, 50-75%, and 75-100%, respectively. 3(27.3%), 3 (27.3%), 1 (9.1%), and 4 (36.4%) of the participants said their epileptic seizures improved by 0-25%, 25-50%, 50-75%, and 75-100%, respectively. The average overall score for quality of life for the study participants was found to be 51 (±8) out of 100. Patients with epilepsy and comorbid PNES may benefit from VNS. It is unclear whether the benefit is conferred strictly from decreased epileptic seizure burden. The possible effect on PNES may be related to the known effect of VNS on depression. Further studies are necessary to elucidate the role of VNS in the treatment of PNES and possibly other psychiatric disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Multi-field query expansion is effective for biomedical dataset retrieval.

PubMed

Bouadjenek, Mohamed Reda; Verspoor, Karin

2017-01-01

In the context of the bioCADDIE challenge addressing information retrieval of biomedical datasets, we propose a method for retrieval of biomedical data sets with heterogenous schemas through query reformulation. In particular, the method proposed transforms the initial query into a multi-field query that is then enriched with terms that are likely to occur in the relevant datasets. We compare and evaluate two query expansion strategies, one based on the Rocchio method and another based on a biomedical lexicon. We then perform a comprehensive comparative evaluation of our method on the bioCADDIE dataset collection for biomedical retrieval. We demonstrate the effectiveness of our multi-field query method compared to two baselines, with MAP improved from 0.2171 and 0.2669 to 0.2996. We also show the benefits of query expansion, where the Rocchio expanstion method improves the MAP for our two baselines from 0.2171 and 0.2669 to 0.335. We show that the Rocchio query expansion method slightly outperforms the one based on the biomedical lexicon as a source of terms, with an improvement of roughly 3% for MAP. However, the query expansion method based on the biomedical lexicon is much less resource intensive since it does not require computation of any relevance feedback set or any initial execution of the query. Hence, in term of trade-off between efficiency, execution time and retrieval accuracy, we argue that the query expansion method based on the biomedical lexicon offers the best performance for a prototype biomedical data search engine intended to be used at a large scale. In the official bioCADDIE challenge results, although our approach is ranked seventh in terms of the infNDCG evaluation metric, it ranks second in term of P@10 and NDCG. Hence, the method proposed here provides overall good retrieval performance in relation to the approaches of other competitors. Consequently, the observations made in this paper should benefit the development of a Data Discovery Index prototype or the improvement of the existing one. © The Author(s) 2017. Published by Oxford University Press.

Multi-field query expansion is effective for biomedical dataset retrieval

PubMed Central

2017-01-01

Abstract In the context of the bioCADDIE challenge addressing information retrieval of biomedical datasets, we propose a method for retrieval of biomedical data sets with heterogenous schemas through query reformulation. In particular, the method proposed transforms the initial query into a multi-field query that is then enriched with terms that are likely to occur in the relevant datasets. We compare and evaluate two query expansion strategies, one based on the Rocchio method and another based on a biomedical lexicon. We then perform a comprehensive comparative evaluation of our method on the bioCADDIE dataset collection for biomedical retrieval. We demonstrate the effectiveness of our multi-field query method compared to two baselines, with MAP improved from 0.2171 and 0.2669 to 0.2996. We also show the benefits of query expansion, where the Rocchio expanstion method improves the MAP for our two baselines from 0.2171 and 0.2669 to 0.335. We show that the Rocchio query expansion method slightly outperforms the one based on the biomedical lexicon as a source of terms, with an improvement of roughly 3% for MAP. However, the query expansion method based on the biomedical lexicon is much less resource intensive since it does not require computation of any relevance feedback set or any initial execution of the query. Hence, in term of trade-off between efficiency, execution time and retrieval accuracy, we argue that the query expansion method based on the biomedical lexicon offers the best performance for a prototype biomedical data search engine intended to be used at a large scale. In the official bioCADDIE challenge results, although our approach is ranked seventh in terms of the infNDCG evaluation metric, it ranks second in term of P@10 and NDCG. Hence, the method proposed here provides overall good retrieval performance in relation to the approaches of other competitors. Consequently, the observations made in this paper should benefit the development of a Data Discovery Index prototype or the improvement of the existing one. PMID:29220457

Improvement of Accuracy for Background Noise Estimation Method Based on TPE-AE

NASA Astrophysics Data System (ADS)

Itai, Akitoshi; Yasukawa, Hiroshi

This paper proposes a method of a background noise estimation based on the tensor product expansion with a median and a Monte carlo simulation. We have shown that a tensor product expansion with absolute error method is effective to estimate a background noise, however, a background noise might not be estimated by using conventional method properly. In this paper, it is shown that the estimate accuracy can be improved by using proposed methods.

Design of a three-dimensional scramjet nozzle considering lateral expansion and geometric constraints

NASA Astrophysics Data System (ADS)

Lv, Zheng; Xu, Jinglei; Mo, Jianwei

2017-12-01

A new method based on quasi two-dimensional supersonic flow and maximum thrust theory to design a three-dimensional nozzle while considering lateral expansion and geometric constraints is presented in this paper. To generate the configuration of the three-dimensional nozzle, the inviscid flowfield is calculated through the method of characteristics, and the reference temperature method is applied to correct the boundary layer thickness. The computational fluid dynamics approach is used to obtain the aerodynamic performance of the nozzle. Results show that the initial arc radius slightly influences the axial thrust coefficient, whereas the variations in the lateral expansion contour, the length and initial expansion angle of the lower cowl significantly affect the axial thrust coefficient. The three-dimensional nozzle designed by streamline tracing technique is also investigated for comparison to verify the superiority of the new method. The proposed nozzle shows increases in the axial thrust coefficient, lift, and pitching moment of 6.86%, 203.15%, and 642.86%, respectively, at the design point, compared with the nozzle designed by streamline tracing approach. In addition, the lateral expansion accounts for 22.46% of the entire axial thrust, while it has no contribution to the lift and pitching moment in the proposed nozzle.

Scaling Symmetries in Elastic-Plastic Dynamic Cavity Expansion Equations Using the Isovector Method

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

Albright, Eric Jason; Ramsey, Scott D.; Schmidt, Joseph H.

Cavity-expansion approximations are widely-used in the study of penetration mechanics and indentation phenomena. We apply the isovector method to a well-established model in the literature for elastic-plastic cavity-expansion to systematically demonstrate the existence of Lie symmetries corresponding to scale-invariant solutions. Here we use the symmetries obtained from the equations of motion to determine compatible auxiliary conditions describing the cavity wall trajectory and the elastic-plastic material interface. The admissible conditions are then compared with specific similarity solutions in the literature.

Cryogenic fiber optic temperature sensor and method of manufacturing the same

NASA Technical Reports Server (NTRS)

Kochergin, Vladimir (Inventor)

2012-01-01

This invention teaches the fiber optic sensors temperature sensors for cryogenic temperature range with improved sensitivity and resolution, and method of making said sensors. In more detail, the present invention is related to enhancement of temperature sensitivity of fiber optic temperature sensors at cryogenic temperatures by utilizing nanomaterials with a thermal expansion coefficient that is smaller than the thermal expansion coefficient of the optical fiber but larger in absolute value than the thermal expansion coefficient of the optical fiber at least over a range of temperatures.

Computing correct truncated excited state wavefunctions

NASA Astrophysics Data System (ADS)

Bacalis, N. C.; Xiong, Z.; Zang, J.; Karaoulanis, D.

2016-12-01

We demonstrate that, if a wave function's truncated expansion is small, then the standard excited states computational method, of optimizing one "root" of a secular equation, may lead to an incorrect wave function - despite the correct energy according to the theorem of Hylleraas, Undheim and McDonald - whereas our proposed method [J. Comput. Meth. Sci. Eng. 8, 277 (2008)] (independent of orthogonality to lower lying approximants) leads to correct reliable small truncated wave functions. The demonstration is done in He excited states, using truncated series expansions in Hylleraas coordinates, as well as standard configuration-interaction truncated expansions.

Scaling Symmetries in Elastic-Plastic Dynamic Cavity Expansion Equations Using the Isovector Method

DOE PAGES

Albright, Eric Jason; Ramsey, Scott D.; Schmidt, Joseph H.; ...

2017-09-16

Cavity-expansion approximations are widely-used in the study of penetration mechanics and indentation phenomena. We apply the isovector method to a well-established model in the literature for elastic-plastic cavity-expansion to systematically demonstrate the existence of Lie symmetries corresponding to scale-invariant solutions. Here we use the symmetries obtained from the equations of motion to determine compatible auxiliary conditions describing the cavity wall trajectory and the elastic-plastic material interface. The admissible conditions are then compared with specific similarity solutions in the literature.

Fast algorithms for Quadrature by Expansion I: Globally valid expansions

NASA Astrophysics Data System (ADS)

Rachh, Manas; Klöckner, Andreas; O'Neil, Michael

2017-09-01

The use of integral equation methods for the efficient numerical solution of PDE boundary value problems requires two main tools: quadrature rules for the evaluation of layer potential integral operators with singular kernels, and fast algorithms for solving the resulting dense linear systems. Classically, these tools were developed separately. In this work, we present a unified numerical scheme based on coupling Quadrature by Expansion, a recent quadrature method, to a customized Fast Multipole Method (FMM) for the Helmholtz equation in two dimensions. The method allows the evaluation of layer potentials in linear-time complexity, anywhere in space, with a uniform, user-chosen level of accuracy as a black-box computational method. Providing this capability requires geometric and algorithmic considerations beyond the needs of standard FMMs as well as careful consideration of the accuracy of multipole translations. We illustrate the speed and accuracy of our method with various numerical examples.

On Partial Fraction Expansion with Multiple Poles. Classroom Notes

ERIC Educational Resources Information Center

Hou, Shui-Hung; Hou, Edwin Sui-Hoi

2004-01-01

A simple and novel method for evaluating the partial fraction expansion of proper rational functions is presented. The technique involves simultaneous determination of the partial fraction coefficients associated with each of the multiple poles in the expansion in turn. Only synthetic division is required, which makes the process very suitable for…

Node-Expansion Operators for the UCT Algorithm

NASA Astrophysics Data System (ADS)

Yajima, Takayuki; Hashimoto, Tsuyoshi; Matsui, Toshiki; Hashimoto, Junichi; Spoerer, Kristian

Recent works on the MCTS and UCT framework in the domain of Go focused on introducing knowledge to the playout and on pruning variations from the tree, but so far node expansion has not been investigated. In this paper we show that delaying expansion according to the number of the siblings delivers a gain of more than 92% when compared to normal expansion. We propose three improvements; one that uses domain knowledge and two that are domain-independent methods. Experimental results show that all advanced operators significantly improve the UCT performance when compared to the basic delaying expansion. From the results we may conclude that the new expansion operators are an appropriate means to improve the UCT algorithm.

Generalized moments expansion applied to the two-dimensional S= 1 /2 Heisenberg model

NASA Astrophysics Data System (ADS)

Mancini, Jay D.; Murawski, Robert K.; Fessatidis, Vassilios; Bowen, Samuel P.

2005-12-01

In this work we derive a generalized moments expansion (GMX), to third order, of which the well-established connected moments expansion and the alternate moments expansion are shown to be special cases. We discuss the benefits of the GMX with respect to the avoidance of singularities which are known to plague such moments methods. We then apply the GMX estimates for the ground-state energy for the two-dimensional S=1/2 Heisenberg square lattice and compare these results to those of both spin-wave theory and the linked-cluster expansion.

Boson expansions based on the random phase approximation representation

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

Pedrocchi, V.G.; Tamura, T.

1984-04-01

A new boson expansion theory based on the random phase approximation is presented. The boson expansions are derived here directly in the random phase approximation representation with the help of a technique that combines the use of the Usui operator with that of a new bosonization procedure, called the term-by-term bosonization method. The present boson expansion theory is constructed by retaining a single collective quadrupole random phase approximation component, a truncation that allows for a perturbative treatment of the whole problem. Both Hermitian, as well as non-Hermitian boson expansions, valid for even nuclei, are obtained.

An experimental investigation of wall boundary layer transition Reynolds numbers in an expansion tube

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.

1974-01-01

Experimental measurements of boundary-layer transition in an expansion-tube test-gas flow are presented along with radial distributions of pitot pressure. An integral method for calculating constant Reynolds number lines for an expansion-tube flow is introduced. Comparison of experimental data and constant Reynolds number calculations has shown that for given conditions, wall boundary-layer transition occurs at a constant Reynolds number in an expansion-tube flow. Operating conditions in the expansion tube were chosen so that the effects of test-gas nonequilibrium on boundary-layer transition could be studied.

Serial Tissue Expansion at the Same Site in Pediatric Patients: Is the Subsequent Expansion Faster?

PubMed Central

Lee, Moon Ki; Park, Seong Oh; Choi, Tae Hyun

2017-01-01

Background Serial tissue expansion is performed to remove giant congenital melanocytic nevi. However, there have been no studies comparing the expansion rate between the subsequent and preceding expansions. In this study, we analyzed the rate of expansion in accordance with the number of surgeries, expander location, expander size, and sex. Methods A retrospective analysis was performed in pediatric patients who underwent tissue expansion for giant congenital melanocytic nevi. We tested four factors that may influence the expansion rate: The number of surgeries, expander location, expander size, and sex. The rate of expansion was calculated by dividing the ‘inflation amount’ by the ‘expander size’. Results The expansion rate, compared with the first-time group, was 1.25 times higher in the second-or-more group (P=0.04) and 1.84 times higher in the third-or-more group (P<0.01). The expansion rate was higher at the trunk than at other sites (P<0.01). There was a tendency of lower expansion rate for larger expanders (P=0.03). Sex did not affect the expansion rate. Conclusions There was a positive correlation between the number of surgeries and the expansion rate, a positive correlation between the expander location and the expansion rate, and a negative correlation between the expander size and the expansion rate. PMID:29076319

Determinants of felt stigma in epilepsy.

PubMed

Aydemir, N; Kaya, B; Yıldız, G; Öztura, I; Baklan, B

2016-05-01

The present study aimed to determine the level of felt stigma, overprotection, concealment, and concerns related to epilepsy in different life domains by using culturally-specific scales for Turkish individuals with epilepsy. Also, it aimed to detect relations among the study variables and to determine the variables which predict felt stigma. For this purpose, felt stigma scale, overprotection scale, concealment of epilepsy scale, and concerns of epilepsy scale were administered to two hundred adult persons with epilepsy (PWE). The results showed that almost half of the participants reported felt stigma, overprotection, concealment of epilepsy, concerns related to future occupation, and concerns related to social life. Almost all the study variables show correlations with each other. Concealment of epilepsy, concerns related to social life, and concerns related to future occupation were found as the predictors of felt stigma. Copyright © 2016 Elsevier Inc. All rights reserved.

An experimental study of arch perimeter and arch width increase with mandibular expansion: a finite element method.

PubMed

Baswaraj; Hemanth, M; Jayasudha; Patil, Chandrashekhargouda; Sunilkumar, P; Raghuveer, H P; Chandralekha, B

2013-01-01

The objective of this study was to estimate the increase in arch perimeter associated with mandibular lateral expansion, To estimate the increase in intermolar width with mandibular lateral expansion and to find out the changes of tooth inclination with mandibular expansion. The mandibular bone with dentition of indian skeletal specimen was obtained. The computer tomogram (CT) slices of the mandible were taken. Finite element model (FEM): Numerical representation of the geometry was created by dividing the geometry into finite number of elements and the elements were connected together with nodes at the junction. The result of the study showed when 10° of lateral expansion was applied to the lower buccal segment at the center of rotation found at 4.3 mm below the root apex of first molar, a space of 1.3 mm between the canine and first premolar, and thus an increase in arch perimeter of 2.6 mm. The tip of the mesiolingual cusp of the first molar moved 4.2 mm laterally, resulting in a change in intermolar width by 8.4 mm. Three-dimensional simulation showed that 1 mm of intermolar expansion increased the arch perimeter by 0.30 mm. As the finite element method evolves and scientists are able to more clearly define physical properties of biological tissues, more accurate information can be generated at the level that other analytical methods cannot fully provide data.This result would be of value clinically for prediction of the effects of mandibular expansion.

Searching and Filtering Tweets: CSIRO at the TREC 2012 Microblog Track

DTIC Science & Technology

2012-11-01

stages. We first evaluate the effect of tweet corpus pre- processing in vanilla runs (no query expansion), and then assess the effect of query expansion...Effect of a vanilla run on D4 index (both realtime and non-real-time), and query expansion methods based on the submitted runs for two sets of queries

Thermal Expansion Behavior in TcO2. Toward Breaking the Tc-Tc Bond.

PubMed

Reynolds, Emily; Zhang, Zhaoming; Avdeev, Maxim; Thorogood, Gordon J; Poineau, Frederic; Czerwinski, Kenneth R; Kimpton, Justin A; Kennedy, Brendan J

2017-08-07

The structure of TcO 2 between 25 and 1000 °C has been determined in situ using X-ray powder diffraction methods and is found to remain monoclinic in space group P2 1 /c. Thermal expansion in TcO 2 is highly anisotropic, with negative thermal expansion of the b axis observed above 700 °C. This is the result of an anomalous expansion along the a axis that is a consequence of weakening of the Tc-Tc bonds.

Accurate double many-body expansion potential energy surface for the 2(1)A' state of N2O.

PubMed

Li, Jing; Varandas, António J C

2014-08-28

An accurate double many-body expansion potential energy surface is reported for the 2(1)A' state of N2O. The new double many-body expansion (DMBE) form has been fitted to a wealth of ab initio points that have been calculated at the multi-reference configuration interaction level using the full-valence-complete-active-space wave function as reference and the cc-pVQZ basis set, and subsequently corrected semiempirically via double many-body expansion-scaled external correlation method to extrapolate the calculated energies to the limit of a complete basis set and, most importantly, the limit of an infinite configuration interaction expansion. The topographical features of the novel potential energy surface are then examined in detail and compared with corresponding attributes of other potential functions available in the literature. Exploratory trajectories have also been run on this DMBE form with the quasiclassical trajectory method, with the thermal rate constant so determined at room temperature significantly enhancing agreement with experimental data.

The generalized scattering coefficient method for plane wave scattering in layered structures

NASA Astrophysics Data System (ADS)

Liu, Yu; Li, Chao; Wang, Huai-Yu; Zhou, Yun-Song

2017-02-01

The generalized scattering coefficient (GSC) method is pedagogically derived and employed to study the scattering of plane waves in homogeneous and inhomogeneous layered structures. The numerical stabilities and accuracies of this method and other commonly used numerical methods are discussed and compared. For homogeneous layered structures, concise scattering formulas with clear physical interpretations and strong numerical stability are obtained by introducing the GSCs. For inhomogeneous layered structures, three numerical methods are employed: the staircase approximation method, the power series expansion method, and the differential equation based on the GSCs. We investigate the accuracies and convergence behaviors of these methods by comparing their predictions to the exact results. The conclusions are as follows. The staircase approximation method has a slow convergence in spite of its simple and intuitive implementation, and a fine stratification within the inhomogeneous layer is required for obtaining accurate results. The expansion method results are sensitive to the expansion order, and the treatment becomes very complicated for relatively complex configurations, which restricts its applicability. By contrast, the GSC-based differential equation possesses a simple implementation while providing fast and accurate results.

The evidence of the rugoscopy effectiveness as a human identification method in patients submitted to rapid palatal expansion.

PubMed

Barbieri, Ana A; Scoralick, Raquel A; Naressi, Suely C M; Moraes, Mari E L; Daruge, Eduardo; Daruge, Eduardo

2013-01-01

The objective of this study was to demonstrate the effectiveness of rugoscopy as a human identification method, even when the patient is submitted to rapid palatal expansion, which in theory would introduce doubt. With this intent, the Rugoscopic Identity was obtained for each subject using the classification formula proposed by Santos based on the intra-oral casts made before and after treatment from patients who were subjected to palatal expansion. The casts were labeled with the patients' initials and randomly arranged for studying. The palatine rugae kept the same patterns in every case studied. The technical error of the intra-evaluator measurement provided a confidence interval of 95%, making rugoscopy a reliable identification method for patients who were submitted to rapid palatal expansion, because even in the presence of intra-oral changes owing to the use of palatal expanders, the palatine rugae retained the biological and technical requirements for the human identification process. © 2012 American Academy of Forensic Sciences.

Engineered artificial antigen presenting cells facilitate direct and efficient expansion of tumor infiltrating lymphocytes

PubMed Central

2011-01-01

Background Development of a standardized platform for the rapid expansion of tumor-infiltrating lymphocytes (TILs) with anti-tumor function from patients with limited TIL numbers or tumor tissues challenges their clinical application. Methods To facilitate adoptive immunotherapy, we applied genetically-engineered K562 cell-based artificial antigen presenting cells (aAPCs) for the direct and rapid expansion of TILs isolated from primary cancer specimens. Results TILs outgrown in IL-2 undergo rapid, CD28-independent expansion in response to aAPC stimulation that requires provision of exogenous IL-2 cytokine support. aAPCs induce numerical expansion of TILs that is statistically similar to an established rapid expansion method at a 100-fold lower feeder cell to TIL ratio, and greater than those achievable using anti-CD3/CD28 activation beads or extended IL-2 culture. aAPC-expanded TILs undergo numerical expansion of tumor antigen-specific cells, remain amenable to secondary aAPC-based expansion, and have low CD4/CD8 ratios and FOXP3+ CD4+ cell frequencies. TILs can also be expanded directly from fresh enzyme-digested tumor specimens when pulsed with aAPCs. These "young" TILs are tumor-reactive, positively skewed in CD8+ lymphocyte composition, CD28 and CD27 expression, and contain fewer FOXP3+ T cells compared to parallel IL-2 cultures. Conclusion Genetically-enhanced aAPCs represent a standardized, "off-the-shelf" platform for the direct ex vivo expansion of TILs of suitable number, phenotype and function for use in adoptive immunotherapy. PMID:21827675

Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

NASA Astrophysics Data System (ADS)

Li, Yongkang; Yang, Yang; He, Changyan

2018-04-01

Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

Lessons from Early Medicaid Expansions Under Health Reform: Interviews with Medicaid Officials

PubMed Central

Sommers, Benjamin D; Arntson, Emily; Kenney, Genevieve M; Epstein, Arnold M

2013-01-01

Background The Affordable Care Act (ACA) dramatically expands Medicaid in 2014 in participating states. Meanwhile, six states have already expanded Medicaid since 2010 to some or all of the low-income adults targeted under health reform. We undertook an in-depth exploration of these six “early-expander” states—California, Connecticut, the District of Columbia, Minnesota, New Jersey, and Washington—through interviews with high-ranking Medicaid officials. Methods We conducted semi-structured interviews with 11 high-ranking Medicaid officials in six states and analyzed the interviews using qualitative methods. Interviews explored enrollment outreach, stakeholder involvement, impact on beneficiaries, utilization and costs, implementation challenges, and potential lessons for 2014. Two investigators independently analyzed interview transcripts and iteratively refined the codebook until reaching consensus. Results We identified several themes. First, these expansions built upon pre-existing state-funded insurance programs for the poor. Second, predictions about costs and enrollment were challenging, indicating the uncertainty in projections for 2014. Other themes included greater than anticipated need for behavioral health services in the expansion population, administrative challenges of expansions, and persistent barriers to enrollment and access after expanding eligibility—though officials overall felt the expansions increased access for beneficiaries. Finally, political context—support or opposition from stakeholders and voters—plays a critical role in shaping the success of Medicaid expansions. Conclusions Early Medicaid expansions under the ACA offer important lessons to federal and state policymakers as the 2014 expansions approach. While the context of each state’s expansion is unique, key shared experiences were significant implementation challenges and opportunities for expanding access to needed services. PMID:24834369

Temperature and Thermal Expansion Analysis of the Cooling Roller Based on the Variable Heat Flux Boundary Condition

NASA Astrophysics Data System (ADS)

Li, Yongkang; Yang, Yang; He, Changyan

2018-06-01

Planar flow casting (PFC) is a primary method for preparing an amorphous ribbon. The qualities of the amorphous ribbon are significantly influenced by the temperature and thermal expansion of the cooling roller. This study proposes a new approach to analyze the three-dimensional temperature and thermal expansion of the cooling roller using variable heat flux that acted on the cooling roller as a boundary condition. First, a simplified two-dimensional model of the PFC is developed to simulate the distribution of the heat flux in the circumferential direction with the software FLUENT. The resulting heat flux is extended to be three-dimensional in the ribbon's width direction. Then, the extended heat flux is imported as the boundary condition by the CFX Expression Language, and the transient temperature of the cooling roller is analyzed in the CFX software. Next, the transient thermal expansion of the cooling roller is simulated through the thermal-structural coupling method. Simulation results show that the roller's temperature and expansion are unevenly distributed, reach the peak value in the middle width direction, and the quasi-steady state of the maximum temperature and thermal expansion are achieved after approximately 50 s and 150 s of casting, respectively. The minimum values of the temperature and expansion are achieved when the roller has a thickness of 45 mm. Finally, the reliability of the approach proposed is verified by measuring the roller's thermal expansion on the spot. This study provides theoretical guidance for the roller's thermal expansion prediction and the gap adjustment in the PFC.

AAC menu interface: effectiveness of active versus passive learning to master abbreviation-expansion codes.

PubMed

Gregory, Ellyn; Soderman, Melinda; Ward, Christy; Beukelman, David R; Hux, Karen

2006-06-01

This study investigated the accuracy with which 30 young adults without disabilities learned abbreviation expansion codes associated with specific vocabulary items that were stored in an AAC device with two accessing methods: mouse access and keyboard access. Both accessing methods utilized a specialized computer application, called AAC Menu, which allowed for errorless practice. Mouse access prompted passive learning, whereas keyboard access prompted active learning. Results revealed that participants who accessed words via a keyboard demonstrated significantly higher mastery of abbreviation-expansion codes than those who accessed words via a computer mouse.

A Method for Measuring Collection Expansion Rates and Shelf Space Capacities.

ERIC Educational Resources Information Center

Sapp, Gregg; Suttle, George

1994-01-01

Describes an effort to quantify annual collection expansion and shelf space capacities with a computer spreadsheet program. Methods used to quantify the space taken at the beginning of the project; to estimate annual rate of collection growth; and to plot stack space and usage, volume equivalents and usage, and growth capacity are covered.…

Method and apparatus for thermal power generation

DOEpatents

Mangus, James D.

1979-01-01

A method and apparatus for power generation from a recirculating superheat-reheat circuit with multiple expansion stages which alleviates complex control systems and minimizes thermal cycling of system components, particularly the reheater. The invention includes preheating cold reheat fluid from the first expansion stage prior to its entering the reheater with fluid from the evaporator or drum component.

New solitary wave solutions of the time-fractional Cahn-Allen equation via the improved (G'/G)-expansion method

NASA Astrophysics Data System (ADS)

Batool, Fiza; Akram, Ghazala

2018-05-01

An improved (G'/G)-expansion method is proposed for extracting more general solitary wave solutions of the nonlinear fractional Cahn-Allen equation. The temporal fractional derivative is taken in the sense of Jumarie's fractional derivative. The results of this article are generalized and extended version of previously reported solutions.

Resonant frequency method for bearing ball inspection

DOEpatents

Khuri-Yakub, B. T.; Hsieh, Chung-Kao

1993-01-01

The present invention provides for an inspection system and method for detecting defects in test objects which includes means for generating expansion inducing energy focused upon the test object at a first location, such expansion being allowed to contract, thereby causing pressure wave within and on the surface of the test object. Such expansion inducing energy may be provided by, for example, a laser beam or ultrasonic energy. At a second location, the amplitudes and phases of the acoustic waves are detected and the resonant frequencies' quality factors are calculated and compared to predetermined quality factor data, such comparison providing information of whether the test object contains a defect. The inspection system and method also includes means for mounting the bearing ball for inspection.

Radial expansion of the tail current disruption during substorms - A new approach to the substorm onset region

NASA Technical Reports Server (NTRS)

Ohtani, S.; Kokubun, S.; Russell, C. T.

1992-01-01

A new method is used to examine the radial expansion of the tail current disruption and the substorm onset region. The expansion of the disruption region is specified by examining the time sequence (phase relationship) between the north-south component and the sun-earth component. This method is tested by applying it to the March 6, 1979, event. The phase relationship indicates that the current disruption started on the earthward side of the spacecraft, and expanded tailward past the spacecraft. The method was used for 13 events selected from the ISEE magnetometer data. The results indicate that the current disruption usually starts in the near-earth magnetotail and often within 15 RE from the earth.

Resonant frequency method for bearing ball inspection

DOEpatents

Khuri-Yakub, B.T.; Chungkao Hsieh.

1993-11-02

The present invention provides for an inspection system and method for detecting defects in test objects which includes means for generating expansion inducing energy focused upon the test object at a first location, such expansion being allowed to contract, thereby causing pressure wave within and on the surface of the test object. Such expansion inducing energy may be provided by, for example, a laser beam or ultrasonic energy. At a second location, the amplitudes and phases of the acoustic waves are detected and the resonant frequencies' quality factors are calculated and compared to predetermined quality factor data, such comparison providing information of whether the test object contains a defect. The inspection system and method also includes means for mounting the bearing ball for inspection. 5 figures.

Dispersive optical soliton solutions for the hyperbolic and cubic-quintic nonlinear Schrödinger equations via the extended sinh-Gordon equation expansion method

NASA Astrophysics Data System (ADS)

Seadawy, Aly R.; Kumar, Dipankar; Chakrabarty, Anuz Kumar

2018-05-01

The (2+1)-dimensional hyperbolic and cubic-quintic nonlinear Schrödinger equations describe the propagation of ultra-short pulses in optical fibers of nonlinear media. By using an extended sinh-Gordon equation expansion method, some new complex hyperbolic and trigonometric functions prototype solutions for two nonlinear Schrödinger equations were derived. The acquired new complex hyperbolic and trigonometric solutions are expressed by dark, bright, combined dark-bright, singular and combined singular solitons. The obtained results are more compatible than those of other applied methods. The extended sinh-Gordon equation expansion method is a more powerful and robust mathematical tool for generating new optical solitary wave solutions for many other nonlinear evolution equations arising in the propagation of optical pulses.

Convergence of Legendre Expansion of Doppler-Broadened Double Differential Elastic Scattering Cross Section

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

Arbanas, Goran; Dunn, Michael E; Larson, Nancy M

2012-01-01

Convergence properties of Legendre expansion of a Doppler-broadened double-differential elastic neutron scattering cross section of {sup 238}U near the 6.67 eV resonance at temperature 10{sup 3} K are studied. A variance of Legendre expansion from a reference Monte Carlo computation is used as a measure of convergence and is computed for as many as 15 terms in the Legendre expansion. When the outgoing energy equals the incoming energy, it is found that the Legendre expansion converges very slowly. Therefore, a supplementary method of computing many higher-order terms is suggested and employed for this special case.

The F(N) method for the one-angle radiative transfer equation applied to plant canopies

NASA Technical Reports Server (NTRS)

Ganapol, B. D.; Myneni, R. B.

1992-01-01

The paper presents a semianalytical solution method, called the F(N) method, for the one-angle radiative transfer equation in slab geometry. The F(N) method is based on two integral equations specifying the intensities exiting the boundaries of the vegetation canopy; the solution is obtained through an expansion in a set of basis functions with expansion coefficients to be determined. The advantage of this method is that it avoids spatial truncation error entirely because it requires discretization only in the angular variable.

Assessment of the further improved (G'/G)-expansion method and the extended tanh-method in probing exact solutions of nonlinear PDEs.

PubMed

Akbar, M Ali; Ali, Norhashidah Hj Mohd; Mohyud-Din, Syed Tauseef

2013-01-01

The (G'/G)-expansion method is one of the most direct and effective method for obtaining exact solutions of nonlinear partial differential equations (PDEs). In the present article, we construct the exact traveling wave solutions of nonlinear evolution equations in mathematical physics via the (2 + 1)-dimensional breaking soliton equation by using two methods: namely, a further improved (G'/G)-expansion method, where G(ξ) satisfies the auxiliary ordinary differential equation (ODE) [G'(ξ)](2) = p G (2)(ξ) + q G (4)(ξ) + r G (6)(ξ); p, q and r are constants and the well known extended tanh-function method. We demonstrate, nevertheless some of the exact solutions bring out by these two methods are analogous, but they are not one and the same. It is worth mentioning that the first method has not been exercised anybody previously which gives further exact solutions than the second one. PACS numbers 02.30.Jr, 05.45.Yv, 02.30.Ik.

Breaking the Link between Environmental Degradation and Oil Palm Expansion: A Method for Enabling Sustainable Oil Palm Expansion

PubMed Central

Smit, Hans Harmen; Meijaard, Erik; van der Laan, Carina; Mantel, Stephan; Budiman, Arif; Verweij, Pita

2013-01-01

Land degradation is a global concern. In tropical areas it primarily concerns the conversion of forest into non-forest lands and the associated losses of environmental services. Defining such degradation is not straightforward hampering effective reduction in degradation and use of already degraded lands for more productive purposes. To facilitate the processes of avoided degradation and land rehabilitation, we have developed a methodology in which we have used international environmental and social sustainability standards to determine the suitability of lands for sustainable agricultural expansion. The method was developed and tested in one of the frontiers of agricultural expansion, West Kalimantan province in Indonesia. The focus was on oil palm expansion, which is considered as a major driver for deforestation in tropical regions globally. The results suggest that substantial changes in current land-use planning are necessary for most new plantations to comply with international sustainability standards. Through visualizing options for sustainable expansion with our methodology, we demonstrate that the link between oil palm expansion and degradation can be broken. Application of the methodology with criteria and thresholds similar to ours could help the Indonesian government and the industry to achieve its pro-growth, pro-job, pro-poor and pro-environment development goals. For sustainable agricultural production, context specific guidance has to be developed in areas suitable for expansion. Our methodology can serve as a template for designing such commodity and country specific tools and deliver such guidance. PMID:24039700

A new framework for modeling urban land expansion in peri-urban area by combining multi-source datasets and data assimilation

NASA Astrophysics Data System (ADS)

Zhang, Z.; Xiao, R.; Li, X.

2015-12-01

Peri-urban area is a new type region under the impacts of both rural Industrialization and the radiation of metropolitan during rapid urbanization. Due to its complex natural and social characteristics and unique development patterns, many problems such as environmental pollution and land use waste emerged, which became an urgent issue to be addressed. Study area in this paper covers three typical peri-urban districts (Pudong, Fengxian and Jinshan), which around the Shanghai inner city. By coupling cellular automata and multi-agent system model as the basic tools, this research focus on modelling the urban land expansion and driving mechanism in peri-urban area. The big data is aslo combined with the Bayesian maximum entropy method (BME) for spatiotemporal prediction of multi-source data, which expand the dataset of urban expansion models. Data assimilation method is used to optimize the parameters of the coupling model and minimize the uncertainty of observations, improving the precision of future simulation in peri-urban area. By setting quantitative parameters, the coupling model can effectively improve the simulation of the process of urban land expansion under different policies and management schemes, in order to provide scientificimplications for new urbanization strategy. In this research, we precise the urban land expansion simulation and prediction for peri-urban area, expand the scopes and selections of data acquisition measurements and methods, develop the new applications of the data assimilation method in geographical science, provide a new idea for understanding the inherent rules of urban land expansion, and give theoretical and practical support for the peri-urban area in urban planning and decision making.

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR.

PubMed

Takegoshi, K; Miyazawa, Norihiro; Sharma, Kshama; Madhu, P K

2015-04-07

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

NASA Astrophysics Data System (ADS)

Takegoshi, K.; Miyazawa, Norihiro; Sharma, Kshama; Madhu, P. K.

2015-04-01

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes with the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.

Comparison among Magnus/Floquet/Fer expansion schemes in solid-state NMR

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

Takegoshi, K., E-mail: takeyan@kuchem.kyoto-u.ac.jp; Miyazawa, Norihiro; Sharma, Kshama

2015-04-07

We here revisit expansion schemes used in nuclear magnetic resonance (NMR) for the calculation of effective Hamiltonians and propagators, namely, Magnus, Floquet, and Fer expansions. While all the expansion schemes are powerful methods there are subtle differences among them. To understand the differences, we performed explicit calculation for heteronuclear dipolar decoupling, cross-polarization, and rotary-resonance experiments in solid-state NMR. As the propagator from the Fer expansion takes the form of a product of sub-propagators, it enables us to appreciate effects of time-evolution under Hamiltonians with different orders separately. While 0th-order average Hamiltonian is the same for the three expansion schemes withmore » the three cases examined, there is a case that the 2nd-order term for the Magnus/Floquet expansion is different from that obtained with the Fer expansion. The difference arises due to the separation of the 0th-order term in the Fer expansion. The separation enables us to appreciate time-evolution under the 0th-order average Hamiltonian, however, for that purpose, we use a so-called left-running Fer expansion. Comparison between the left-running Fer expansion and the Magnus expansion indicates that the sign of the odd orders in Magnus may better be reversed if one would like to consider its effect in order.« less

Reconstructing the metric of the local Universe from number counts observations

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

Vallejo, Sergio Andres; Romano, Antonio Enea, E-mail: antonio.enea.romano@cern.ch

Number counts observations available with new surveys such as the Euclid mission will be an important source of information about the metric of the Universe. We compute the low red-shift expansion for the energy density and the density contrast using an exact spherically symmetric solution in presence of a cosmological constant. At low red-shift the expansion is more precise than linear perturbation theory prediction. We then use the local expansion to reconstruct the metric from the monopole of the density contrast. We test the inversion method using numerical calculations and find a good agreement within the regime of validity ofmore » the red-shift expansion. The method could be applied to observational data to reconstruct the metric of the local Universe with a level of precision higher than the one achievable using perturbation theory.« less

Simplified Technique for Predicting Offshore Pipeline Expansion

NASA Astrophysics Data System (ADS)

Seo, J. H.; Kim, D. K.; Choi, H. S.; Yu, S. Y.; Park, K. S.

2018-06-01

In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs, which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio (SDR) versus virtual anchor length (L A ) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline, offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.

Model test on partial expansion in stratified subsidence during foundation pit dewatering

NASA Astrophysics Data System (ADS)

Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

2018-02-01

Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be revised and improved.

Pressurized electrolysis stack with thermal expansion capability

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

Bourgeois, Richard Scott

The present techniques provide systems and methods for mounting an electrolyzer stack in an outer shell so as to allow for differential thermal expansion of the electrolyzer stack and shell. Generally, an electrolyzer stack may be formed from a material with a high coefficient of thermal expansion, while the shell may be formed from a material having a lower coefficient of thermal expansion. The differences between the coefficients of thermal expansion may lead to damage to the electrolyzer stack as the shell may restrain the thermal expansion of the electrolyzer stack. To allow for the differences in thermal expansion, themore » electrolyzer stack may be mounted within the shell leaving a space between the electrolyzer stack and shell. The space between the electrolyzer stack and the shell may be filled with a non-conductive fluid to further equalize pressure inside and outside of the electrolyzer stack.« less

Thermal Expansion of Ferromagnetic Superconductors:. Possible Application to UGe2

NASA Astrophysics Data System (ADS)

Hatayama, Nobukuni; Konno, Rikio

2011-03-01

We investigate the temperature dependence of thermal expansion of the ferromagnetic triplet superconductors and their thermal expansion coefficients below the superconducting transition temperature of a majority spin conduction band. The free energy of the ferromagnetic superconductors derived by Linder et al. is used. The superconducting gaps in the A2 phase of 3He and with a node in UGe2 are considered. By applying Takahashi's method to the free energy, i.e. by taking into account the volume dependence of the free energy explicitly, the temperature dependence of the thermal expansion and the thermal expansion coefficients is studied below the superconducting transition temperature of the majority spin conduction band. We find that we have anomalies of the thermal expansion in the vicinity of the superconducting transition temperatures and that we have divergence of the thermal expansion coefficients are divergent at the superconducting transition temperatures. The Grüneisen's relation between the temperature dependence of the thermal expansion coefficients and the temperature dependence of the specific heat at low temperatures is satisfied.

Thermal Expansion of Ferromagnetic Superconductors:. Possible Application to UGe2

NASA Astrophysics Data System (ADS)

Hatayama, Nobukuni; Konno, Rikio

We investigate the temperature dependence of thermal expansion of the ferromagnetic triplet superconductors and their thermal expansion coefficients below the superconducting transition temperature of a majority spin conduction band. The free energy of the ferromagnetic superconductors derived by Linder et al. is used. The superconducting gaps in the A2 phase of 3He and with a node in UGe2 are considered. By applying Takahashi's method to the free energy, i.e. by taking into account the volume dependence of the free energy explicitly, the temperature dependence of the thermal expansion and the thermal expansion coefficients is studied below the superconducting transition temperature of the majority spin conduction band. We find that we have anomalies of the thermal expansion in the vicinity of the superconducting transition temperatures and that we have divergence of the thermal expansion coefficients are divergent at the superconducting transition temperatures. The Grüneisen's relation between the temperature dependence of the thermal expansion coefficients and the temperature dependence of the specific heat at low temperatures is satisfied.

A unified perturbation expansion for surface scattering

NASA Technical Reports Server (NTRS)

Rodriguez, Ernesto; Kim, Yunjin

1992-01-01

Starting with the extinction theorem, a perturbation expansion which, to first and second orders, converges over a wider domain than the small perturbation expansion and the momentum transfer expansion is presented. It is shown that, in the appropriate limits, both of these theories, as well as the two-scale expansion, are recovered. There is no adjustable parameter, such as a spectral split, in the theory. This theory is applied to random rough surfaces and derive analytic expressions for the coherent field and the bistatic cross section. Finally, a numerical test of the theory against method of moments results for Gaussian random rough surfaces with a power law spectrum is given. These results show that the expansion is ramarkably accurate over a large range of surface heights and slopes for both horizontal and vertical polarization.

Detection of Large Pathogenic Expansions in FRDA1, SCA10, and SCA12 Genes Using a Simple Fluorescent Repeat-Primed PCR Assay

PubMed Central

Cagnoli, Claudia; Michielotto, Chiara; Matsuura, Tohru; Ashizawa, Tetsuo; Margolis, Russell L.; Holmes, Susan E.; Gellera, Cinzia; Migone, Nicola; Brusco, Alfredo

2004-01-01

At least 18 human genetic diseases are caused by expansion of short tandem repeats. Here we describe a successful application of a fluorescent PCR method for the detection of expanded repeats in FRDA1, SCA10, and SCA12 genes. Although this test cannot give a precise estimate of the size of the expansion, it is robust, reliable, and inexpensive, and can be used to screen large series of patients. It proved useful for confirming the presence of large expansions in the Friedreich ataxia gene following an ambiguous result of long-range PCR, as well as rapid pre-screening for large repeat expansions associated with Friedreich ataxia and SCA10 and the shorter repeat expansions associated with SCA12. PMID:15096564

An Analytical Diffusion–Expansion Model for Forbush Decreases Caused by Flux Ropes

NASA Astrophysics Data System (ADS)

Dumbović, Mateja; Heber, Bernd; Vršnak, Bojan; Temmer, Manuela; Kirin, Anamarija

2018-06-01

We present an analytical diffusion–expansion Forbush decrease (FD) model ForbMod, which is based on the widely used approach of an initially empty, closed magnetic structure (i.e., flux rope) that fills up slowly with particles by perpendicular diffusion. The model is restricted to explaining only the depression caused by the magnetic structure of the interplanetary coronal mass ejection (ICME). We use remote CME observations and a 3D reconstruction method (the graduated cylindrical shell method) to constrain initial boundary conditions of the FD model and take into account CME evolutionary properties by incorporating flux rope expansion. Several flux rope expansion modes are considered, which can lead to different FD characteristics. In general, the model is qualitatively in agreement with observations, whereas quantitative agreement depends on the diffusion coefficient and the expansion properties (interplay of the diffusion and expansion). A case study was performed to explain the FD observed on 2014 May 30. The observed FD was fitted quite well by ForbMod for all expansion modes using only the diffusion coefficient as a free parameter, where the diffusion parameter was found to correspond to an expected range of values. Our study shows that, in general, the model is able to explain the global properties of an FD caused by a flux rope and can thus be used to help understand the underlying physics in case studies.

A phase cell cluster expansion for Euclidean field theories

NASA Astrophysics Data System (ADS)

Battle, Guy A., III; Federbush, Paul

1982-08-01

We adapt the cluster expansion first used to treat infrared problems for lattice models (a mass zero cluster expansion) to the usual field theory situation. The field is expanded in terms of special block spin functions and the cluster expansion given in terms of the expansion coefficients (phase cell variables); the cluster expansion expresses correlation functions in terms of contributions from finite coupled subsets of these variables. Most of the present work is carried through in d space time dimensions (for φ24 the details of the cluster expansion are pursued and convergence is proven). Thus most of the results in the present work will apply to a treatment of φ34 to which we hope to return in a succeeding paper. Of particular interest in this paper is a substitute for the stability of the vacuum bound appropriate to this cluster expansion (for d = 2 and d = 3), and a new method for performing estimates with tree graphs. The phase cell cluster expansions have the renormalization group incorporated intimately into their structure. We hope they will be useful ultimately in treating four dimensional field theories.

Unusual transformation from strong negative to positive thermal expansion in PbTiO3-BiFeO3 perovskite.

PubMed

Chen, Jun; Fan, Longlong; Ren, Yang; Pan, Zhao; Deng, Jinxia; Yu, Ranbo; Xing, Xianran

2013-03-15

Tetragonal PbTiO(3)-BiFeO(3) exhibits a strong negative thermal expansion in the PbTiO(3)-based ferroelectrics that consist of one branch in the family of negative thermal expansion materials. Its strong negative thermal expansion is much weakened, and then unusually transforms into positive thermal expansion as the particle size is slightly reduced. This transformation is a new phenomenon in the negative termal expansion materials. The detailed structure, temperature dependence of unit cell volume, and lattice dynamics of PbTiO(3)-BiFeO(3) samples were studied by means of high-energy synchrotron powder diffraction and Raman spectroscopy. Such unusual transformation from strong negative to positive thermal expansion is highly associated with ferroelectricity weakening. An interesting zero thermal expansion is achieved in a wide temperature range (30-500 °C) by adjusting particle size due to the negative-to-positive transformation character. The present study provides a useful method to control the negative thermal expansion not only for ferroelectrics but also for those functional materials such as magnetics and superconductors.

77 FR 4360 - Notice of Availability of the Draft Environmental Impact Statement for the Hycroft Mine Expansion...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... comments related to the Hycroft Mine Expansion Draft EIS by any of the following methods: Web site: www.blm..., Nevada 89445, Attn. Kathleen Rehberg. Copies of the Hycroft Mine Expansion Draft EIS are available in the... hours. The FIRS is available 24 hours a day, 7 days a week, to leave a message or question with the...

Rapid replacement of bridge deck expansion joints study - phase I : [tech transfer summary].

DOT National Transportation Integrated Search

2014-12-01

This initial research phase focused on documenting the current : means and methods of bridge expansion joint deterioration, : maintenance, and replacement and on identifying improvements : through all of the input gathered.

Short-time self-diffusion coefficient of a particle in a colloidal suspension bounded by a microchannel: Virial expansions and simulation

NASA Astrophysics Data System (ADS)

Kȩdzierski, Marcin; Wajnryb, Eligiusz

2011-10-01

Self-diffusion of colloidal particles confined to a cylindrical microchannel is considered theoretically and numerically. Virial expansion of the self-diffusion coefficient is performed. Two-body and three-body hydrodynamic interactions are evaluated with high precision using the multipole method. The multipole expansion algorithm is also used to perform numerical simulations of the self-diffusion coefficient, valid for all possible particle packing fractions. Comparison with earlier results shows that the widely used method of reflections is insufficient for calculations of hydrodynamic interactions even for small packing fractions and small particles radii, contrary to the prevalent opinion.

Thermal expansion of composites: Methods and results. [large space structures

NASA Technical Reports Server (NTRS)

Bowles, D. E.; Tenney, D. R.

1981-01-01

The factors controlling the dimensional stability of various components of large space structures were investigated. Cyclic, thermal and mechanical loading were identified as the primary controlling factors of the dimensional stability of cables. For organic matrix composites, such as graphite-epoxy, it was found that these factors include moisture desorption in the space environment, thermal expansion as the structure moves from the sunlight to shadow in its orbit, mechanical loading, and microyielding of the material caused by microcracking of the matrix material. The major focus was placed on the thermal expansion of composites and in particular the development and testing of a method for its measurement.

Cylinder Expansion Experiments and Measured Product Isentropes for XTX-8004 Explosive

NASA Astrophysics Data System (ADS)

Jackson, Scott

2015-06-01

We present cylinder expansion data from full-scale (25.4-mm inner diameter) and half-scale (12.7-mm inner diameter) experiments with XTX-8004 explosive, composed of 80% RDX explosive and 20% Sylgard 182 silicone elastomer. An analytic method is reviewed and used to recover detonation product isentropes from the experimental data, which are presented in the standard JWL form. The cylinder expansion data was found to scale well, indicating ideal detonation behavior across the test scales. The analytically determined product JWLs were found to agree well with those produced via iterative hydrocode methods, but required significantly less computational effort.

Exact stochastic unraveling of an optical coherence dynamics by cumulant expansion

NASA Astrophysics Data System (ADS)

Olšina, Jan; Kramer, Tobias; Kreisbeck, Christoph; Mančal, Tomáš

2014-10-01

A numerically exact Monte Carlo scheme for calculation of open quantum system dynamics is proposed and implemented. The method consists of a Monte Carlo summation of a perturbation expansion in terms of trajectories in Liouville phase-space with respect to the coupling between the excited states of the molecule. The trajectories are weighted by a complex decoherence factor based on the second-order cumulant expansion of the environmental evolution. The method can be used with an arbitrary environment characterized by a general correlation function and arbitrary coupling strength. It is formally exact for harmonic environments, and it can be used with arbitrary temperature. Time evolution of an optically excited Frenkel exciton dimer representing a molecular exciton interacting with a charge transfer state is calculated by the proposed method. We calculate the evolution of the optical coherence elements of the density matrix and linear absorption spectrum, and compare them with the predictions of standard simulation methods.

Illness concept among people with epilepsy and their caregivers and preferred treatment methods in a suburban community in Southeast Nigeria.

PubMed

Nwani, P O; Arinzechi, E O; Asomugha, A L; Enwereji, K O; Nwosu, M C; Ogunniyi, A O

2013-01-01

Epilepsy, one of the world's most prevalent chronic diseases is still regarded as a supernatural disease in many parts of the world. These superstitious and cultural beliefs tend to influence treatment seeking behavior of people living with epilepsy (PWE) and their caregivers. People living with epilepsy in a semi-urban community in Southeast Nigeria were identified in a two phase door-to-door cross-sectional descriptive study. Those identified and their caregivers were further interviewed to determine their concepts of the disease, their treatment (actual and preferred) and what informed treatment. We found 29 cases of active epilepsy, 16 (55.2%) males and 13 (44.8%) females. Witchcraft was held as a major cause of epilepsy in the community accounting for 36.2% (n=17) of the responses. The three major treatment modalities used were spiritual (healing churches), traditional (herbal medicines) and orthodox treatment with antiepileptic drugs. Spiritual treatment was the preferred treatment modality, though most (89.7%) have used traditional (herbal medicine) treatment at one point in the course of the disease. Beliefs on epilepsy and information on the disease obtained mostly from non-medical sources informed treatment. The epileptic population studied preferred spiritual treatment though use of traditional treatment was also common. Treatment seeking behavior was greatly influenced by their beliefs and information on the disease obtained mainly from non-medical sources.

The Hubble flow of plateau inflation

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

Coone, Dries; Roest, Diederik; Vennin, Vincent, E-mail: a.a.coone@rug.nl, E-mail: d.roest@rug.nl, E-mail: vincent.vennin@port.ac.uk

2015-11-01

In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard ''horizon flow'' procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau inflation, which suggests the use of Padé approximants instead. We propose a novel method that provides analytic solutions of the flow equations for a given parametrization of the Hubble function. This method is illustrated in the Taylor and Padé cases, for low order expansions. We then present the results of a full numerical treatment scanning larger ordermore » expansions, and compare these parametrizations in terms of convergence, prior dependence, predictivity and compatibility with the data. Finally, we highlight the implications for potential reconstruction methods.« less

Marital status of people with epilepsy in Korea.

PubMed

Kim, Myeong-Kyu; Kwon, Oh-Young; Cho, Yong-Won; Kim, Yosik; Kim, Sung-Eun; Kim, Hoo-Won; Lee, Sang Kun; Jung, Ki-Young; Lee, Il Keun

2010-11-01

A multicentre face-to-face interview was conducted to identify factors contributing to the marital status of people with epilepsy (PWE) in Korea. The marriage rate of PWEs was only 80% and the divorce rate was more than double that in the general population. Among the single subjects, 34% replied that they were unmarried because of epilepsy, and 76% of divorced PWEs replied that epilepsy was the cause of the divorce. The factors affecting the single and divorced status in PWEs included gender, an earlier onset of seizure and seizure onset before marriage. Not informing the spouse of the disease before marriage for fear of discrimination was not related to disadvantage in marriage negotiation or to divorce. Social stigmatization of epilepsy continues and impacts on the marital status of PWEs in Korea. However, there is no correlation between the perceived and the enacted stigmas of epilepsy. Copyright © 2010 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Analytical studies on the Benney-Luke equation in mathematical physics

NASA Astrophysics Data System (ADS)

Islam, S. M. Rayhanul; Khan, Kamruzzaman; Woadud, K. M. Abdul Al

2018-04-01

The enhanced (G‧/G)-expansion method presents wide applicability to handling nonlinear wave equations. In this article, we find the new exact traveling wave solutions of the Benney-Luke equation by using the enhanced (G‧/G)-expansion method. This method is a useful, reliable, and concise method to easily solve the nonlinear evaluation equations (NLEEs). The traveling wave solutions have expressed in term of the hyperbolic and trigonometric functions. We also have plotted the 2D and 3D graphics of some analytical solutions obtained in this paper.

Resonant vibrations of a submerged beam

NASA Astrophysics Data System (ADS)

Achenbach, J. D.; Qu, J.

1986-03-01

Forced vibration of a simply supported submerged beam of circular cross section is investigated by the use of two mathematical methods. In the first approach the problem formulation is reduced to a singular integro-differential equation for the transverse deflection. In the second approach the method of matched asymptotic expansions is employed. The integro-differential equation is solved numerically, to yield an exact solution for the frequency response. Subsequent use of a representation integral yields the radiated far field acoustic pressure. The exact results for the beam deflection are compared with approximate results that are available in the literature. Next, a matched asymptotic expansion is worked out by constructing "inner" and "outer" expansions for frequencies near and not near resonance frequencies, respectively. The two expansions are matched in an appropriate manner to yield a uniformly valid solution. The leading term of the matched asymptotic solution is compared with exact numerical results.

Interactive application of quadratic expansion of chi-square statistic to nonlinear curve fitting

NASA Technical Reports Server (NTRS)

Badavi, F. F.; Everhart, Joel L.

1987-01-01

This report contains a detailed theoretical description of an all-purpose, interactive curve-fitting routine that is based on P. R. Bevington's description of the quadratic expansion of the Chi-Square statistic. The method is implemented in the associated interactive, graphics-based computer program. Taylor's expansion of Chi-Square is first introduced, and justifications for retaining only the first term are presented. From the expansion, a set of n simultaneous linear equations is derived, then solved by matrix algebra. A brief description of the code is presented along with a limited number of changes that are required to customize the program of a particular task. To evaluate the performance of the method and the goodness of nonlinear curve fitting, two typical engineering problems are examined and the graphical and tabular output of each is discussed. A complete listing of the entire package is included as an appendix.

Thermal expansion and magnetostriction measurements at cryogenic temperature using the strain gage method

NASA Astrophysics Data System (ADS)

Wang, Wei; Liu, Huiming; Huang, Rongjin; Zhao, Yuqiang; Huang, Chuangjun; Guo, Shibin; Shan, Yi; Li, Laifeng

2018-03-01

Thermal expansion and magnetostriction, the strain responses of a material to temperature and a magnetic field, especially properties at low temperature, are extremely useful to study electronic and phononic properties, phase transitions, quantum criticality, and other interesting phenomena in cryogenic engineering and materials science. However, traditional dilatometers cannot provide magnetic field and ultra low temperature (＜77 K) environment easily. This paper describes the design and test results of thermal expansion and magnetostriction at cryogenic temperature using the strain gage method based on a Physical Properties Measurements System (PPMS). The interfacing software and automation were developed using LabVIEW. The sample temperature range can be tuned continuously between 1.8 K and 400 K. With this PPMS-aided measuring system, we can observe temperature and magnetic field dependence of the linear thermal expansion of different solid materials easily and accurately.

Spreading devices into a 2-D module layout

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

Koplow, Jeffrey P.; Gupta, Vipin P.; Nielson, Gregory N.

An apparatus, method, and system, the apparatus including a receiving member dimensioned to receive an array of microelectronic devices; and a linkage member coupled to the receiving member, the linkage member configured to move the receiving member in at least two dimensions so as to modify a spacing between the electronic devices within the array of microelectronic devices received by the receiving member. The method including coupling an array of microelectronic devices to an expansion assembly; and expanding the expansion assembly so as to expand the array of microelectronic devices in at least two directions within a single plane. Themore » system including a support member; an expansion assembly coupled to the support member, the expansion assembly having a plurality of receiving members configured to move in at least two dimensions within a single plane; and a plurality of microelectronic devices coupled to each of the plurality of receiving members.« less

The accurate solution of Poisson's equation by expansion in Chebyshev polynomials

NASA Technical Reports Server (NTRS)

Haidvogel, D. B.; Zang, T.

1979-01-01

A Chebyshev expansion technique is applied to Poisson's equation on a square with homogeneous Dirichlet boundary conditions. The spectral equations are solved in two ways - by alternating direction and by matrix diagonalization methods. Solutions are sought to both oscillatory and mildly singular problems. The accuracy and efficiency of the Chebyshev approach compare favorably with those of standard second- and fourth-order finite-difference methods.

Exploring Teachers' Technological Pedagogical Content Knowledge (TPACK) in an Online Course: A Mixed Methods Study

ERIC Educational Resources Information Center

Varguez, Ricardo

2012-01-01

The constant expansion of Web 2.0 applications available on the World Wide Web and expansion of technology resources has prompted the need to better prepare current and future educators to make more effective use of such resources in their classrooms. The purpose of this embedded mixed methods case study was to describe the experiences and changes…

Spatial Dimension as a Variable in Quantum Mechanics

NASA Astrophysics Data System (ADS)

Doren, Douglas James

Several approximation methods potentially useful in electronic structure calculations are developed. These methods all treat the spatial dimension, D, as a variable. In an Introduction, the motivations for these methods are described, with special attention to the semiclassical 1/D expansion. Several terms in this expansion have been calculated for two-electron atoms. The results have qualitative appeal but poor convergence properties when D = 3. Chapter 1 shows that this convergence problem is due to singularities in the energy at D = 1 and a method of removing their effects is demonstrated. Chapter 2 treats several model problems, showing how to identify special dimensions at which the energy becomes singular or the Hamiltonian simplifies. Expansions are developed about these special finite values of D which are quite accurate at low order, regardless of the physical parameters of the Hamiltonian. In Chapter 3, expansions about singular points in the energy at finite values of D are used to resum the 1/D series in cases where its leading orders are not sufficient. This leads to a hybrid expansion which typically improves on both the 1/D and the finite D series. These methods are applied in Chapter 4 to two -electron atoms. The ground state energy of few-electron systems is dominated by the presence of a pole when D = 1. The residue of this pole is determined by the eigenvalue of a simple limiting Schrodinger equation. The limit and first order correction are determined for both unapproximated nonrelativistic two-electron atoms and the Hartree-Fock approximation to them. The hybrid expansion using only the first few terms in the 1/D series determines the energy at arbitrary D, providing estimates accurate to four or five figures when D = 3. Degeneracies between D = 3 states and those in nonphysical dimensions are developed in Chapter 5 which provide additional applications for this series. Chapter 6 illustrates these methods in an application to the H(' -) ion, an especially stringent test case. Proposals for future work in this field are described in the final chapter.

The effects of micro-implant assisted rapid palatal expansion (MARPE) on the nasomaxillary complex--a finite element method (FEM) analysis.

PubMed

MacGinnis, Matt; Chu, Howard; Youssef, George; Wu, Kimberley W; Machado, Andre Wilson; Moon, Won

2014-08-29

Orthodontic palatal expansion appliances have been widely used with satisfactory and, most often, predictable clinical results. Recently, clinicians have successfully utilized micro-implants with palatal expander designs to work as anchors to the palate to achieve more efficient skeletal expansion and to decrease undesired dental effects. The purpose of the study was to use finite element method (FEM) to determine the stress distribution and displacement within the craniofacial complex when simulated conventional and micro-implant-assisted rapid palatal expansion (MARPE) expansion forces are applied to the maxilla. The simulated stress distribution produced within the palate and maxillary buttresses in addition to the displacement and rotation of the maxilla could then be analyzed to determine if micro-implants aid in skeletal expansion. A three-dimensional (3D) mesh model of the cranium with associated maxillary sutures was developed using computed tomography (CT) images and Mimics modeling software. To compare transverse expansion stresses in rapid palatal expansion (RPE) and MARPE, expansion forces were distributed to differing points on the maxilla and evaluated with ANSYS simulation software. The stresses distributed from forces applied to the maxillary teeth are distributed mainly along the trajectories of the three maxillary buttresses. In comparison, the MARPE showed tension and compression directed to the palate, while showing less rotation, and tipping of the maxillary complex. In addition, the conventional hyrax displayed a rotation of the maxilla around the teeth as opposed to the midpalatal suture of the MARPE. This data suggests that the MARPE causes the maxilla to bend laterally, while preventing unwanted rotation of the complex. In conclusion, the MARPE may be beneficial for hyperdivergent patients, or those that have already experienced closure of the midpalatal suture, who require palatal expansion and would worsen from buccal tipping of the teeth or maxillary complex.

Solution of the relativistic asymptotic equations in electron-ion scattering

NASA Astrophysics Data System (ADS)

Young, I. G.; Norrington, P. H.

1994-12-01

Two asymptotic expansions are suggested for the solution of the coupled equations for the radial channel wavefunctions arising from the treament of electron-ion scattering using the Dirac Hamiltonian. The recurrence relations obtained for the expansions coefficients are given. A method is suggested for calculation of the one-electron Dirac-Coulomb functions used in the second expansion using solutions of the non-relativistic Coulomb equation with complex arguments.

The Forbin Paper.

DTIC Science & Technology

1987-07-01

Network for Constructing a Widget and Gizmo 46 14 The Task Network After One Round of Expansion ............. 48 15 The Further Expansion of the MAKE...Widget Task .............. 49 16 The Further Expansion of the MAKE Gizmo Task ............ ... 50 17 Choosing the INSTALL-I METHOD...component of the planner’s knowledge. The task expander implements the 101 Network A MAKE Widget I time=O MAKE Gizmo Network B MAKE Widget time=35 MAKE

One-loop topological expansion for spin glasses in the large connectivity limit

NASA Astrophysics Data System (ADS)

Chiara Angelini, Maria; Parisi, Giorgio; Ricci-Tersenghi, Federico

2018-01-01

We apply for the first time a new one-loop topological expansion around the Bethe solution to the spin-glass model with a field in the high connectivity limit, following the methodological scheme proposed in a recent work. The results are completely equivalent to the well-known ones, found by standard field-theoretical expansion around the fully connected model (Bray and Roberts 1980, and following works). However this method has the advantage that the starting point is the original Hamiltonian of the model, with no need to define an associated field theory, nor to know the initial values of the couplings, and the computations have a clear and simple physical meaning. Moreover this new method can also be applied in the case of zero temperature, when the Bethe model has a transition in field, contrary to the fully connected model that is always in the spin-glass phase. Sharing with finite-dimensional model the finite connectivity properties, the Bethe lattice is clearly a better starting point for an expansion with respect to the fully connected model. The present work is a first step towards the generalization of this new expansion to more difficult and interesting cases as the zero-temperature limit, where the expansion could lead to different results with respect to the standard one.

Transformation between surface spherical harmonic expansion of arbitrary high degree and order and double Fourier series on sphere

NASA Astrophysics Data System (ADS)

Fukushima, Toshio

2018-02-01

In order to accelerate the spherical harmonic synthesis and/or analysis of arbitrary function on the unit sphere, we developed a pair of procedures to transform between a truncated spherical harmonic expansion and the corresponding two-dimensional Fourier series. First, we obtained an analytic expression of the sine/cosine series coefficient of the 4 π fully normalized associated Legendre function in terms of the rectangle values of the Wigner d function. Then, we elaborated the existing method to transform the coefficients of the surface spherical harmonic expansion to those of the double Fourier series so as to be capable with arbitrary high degree and order. Next, we created a new method to transform inversely a given double Fourier series to the corresponding surface spherical harmonic expansion. The key of the new method is a couple of new recurrence formulas to compute the inverse transformation coefficients: a decreasing-order, fixed-degree, and fixed-wavenumber three-term formula for general terms, and an increasing-degree-and-order and fixed-wavenumber two-term formula for diagonal terms. Meanwhile, the two seed values are analytically prepared. Both of the forward and inverse transformation procedures are confirmed to be sufficiently accurate and applicable to an extremely high degree/order/wavenumber as 2^{30} {≈ } 10^9. The developed procedures will be useful not only in the synthesis and analysis of the spherical harmonic expansion of arbitrary high degree and order, but also in the evaluation of the derivatives and integrals of the spherical harmonic expansion.

Electric Grid Expansion Planning with High Levels of Variable Generation

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

Hadley, Stanton W.; You, Shutang; Shankar, Mallikarjun

2016-02-01

Renewables are taking a large proportion of generation capacity in U.S. power grids. As their randomness has increasing influence on power system operation, it is necessary to consider their impact on system expansion planning. To this end, this project studies the generation and transmission expansion co-optimization problem of the US Eastern Interconnection (EI) power grid with a high wind power penetration rate. In this project, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. This study analyzed a time series creation method to capture the diversity of load and wind powermore » across balancing regions in the EI system. The obtained time series can be easily introduced into the MIP co-optimization problem and then solved robustly through available MIP solvers. Simulation results show that the proposed time series generation method and the expansion co-optimization model and can improve the expansion result significantly after considering the diversity of wind and load across EI regions. The improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare. This study shows that modelling load and wind variations and diversities across balancing regions will produce significantly different expansion result compared with former studies. For example, if wind is modeled in more details (by increasing the number of wind output levels) so that more wind blocks are considered in expansion planning, transmission expansion will be larger and the expansion timing will be earlier. Regarding generation expansion, more wind scenarios will slightly reduce wind generation expansion in the EI system and increase the expansion of other generation such as gas. Also, adopting detailed wind scenarios will reveal that it may be uneconomic to expand transmission networks for transmitting a large amount of wind power through a long distance in the EI system. Incorporating more details of renewables in expansion planning will inevitably increase the computational burden. Therefore, high performance computing (HPC) techniques are urgently needed for power system operation and planning optimization. As a scoping study task, this project tested some preliminary parallel computation techniques such as breaking down the simulation task into several sub-tasks based on chronology splitting or sample splitting, and then assigning these sub-tasks to different cores. Testing results show significant time reduction when a simulation task is split into several sub-tasks for parallel execution.« less

Stability and adaptability of popcorn genotypes in the State of Rio de Janeiro, Brazil.

PubMed

Pena, G F; do Amaral, A T; Gonçalves, L S A; Candido, L S; Vittorazzi, C; Ribeiro, R M; Freitas, S P

2012-08-31

This study aimed to obtain estimates of stability and adaptability of phase launched materials and materials recommended in the country, for the northern and northwestern regions of Rio de Janeiro State, Brazil, and made a comparative analysis of different methods to evaluate stability and adaptability of grain yield and popping expansion. To this end, 10 genotypes were evaluated (UNB2U-C3, UNB2U-C4, BRS Angela, Viçosa, Beija-Flor, IAC 112, IAC 125, Zélia, Jade, and UFVM2 Barão de Viçosa) in five environments. The Yates and Cochran method revealed that genotypes UFV2M Barão de Viçosa, BRS Angela and UNB2U-C3 were the most stable for grain yield. This method also indicated superiority of genotypes UNB2U-C3, UNB2U-C4, BRS Angela, Viçosa, IAC 125, and Zélia for popping expansion. The Plaisted and Peterson and Wricke methods demonstrated that genotypes Zélia and UNB2U-C4 were the most productive and stable. These methods indicated genotypes UNB2U-C3 and BRS Angela as the most stable for popping expansion. The Kang and Phan ranking system uses methods based on analysis of variance and classified population UNB2U-C4 as the genotype with the highest stability of grain production and confirmed cultivar BRS Angela as the most stable for popping expansion. Genotypes IAC 112 and UNB2U-C4 were the most stable and adapted for grain yield, according to the Lin and Binns method. The P(i) statistics also ranked UNB2U-C3 and UNB2U-C4 as the genotypes with the best predictability and capacity for popping expansion.

Self-force calculations with matched expansions and quasinormal mode sums

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

Casals, Marc; Dolan, Sam; Ottewill, Adrian C.

2009-06-15

Accurate modeling of gravitational wave emission by extreme-mass ratio inspirals is essential for their detection by the LISA mission. A leading perturbative approach involves the calculation of the self-force acting upon the smaller orbital body. In this work, we present the first application of the Poisson-Wiseman-Anderson method of 'matched expansions' to compute the self-force acting on a point particle moving in a curved spacetime. The method employs two expansions for the Green function, which are, respectively, valid in the 'quasilocal' and 'distant past' regimes, and which may be matched together within the normal neighborhood. We perform our calculation in amore » static region of the spherically symmetric Nariai spacetime (dS{sub 2}xS{sup 2}), in which scalar-field perturbations are governed by a radial equation with a Poeschl-Teller potential (frequently used as an approximation to the Schwarzschild radial potential) whose solutions are known in closed form. The key new ingredients in our study are (i) very high order quasilocal expansions and (ii) expansion of the distant past Green function in quasinormal modes. In combination, these tools enable a detailed study of the properties of the scalar-field Green function. We demonstrate that the Green function is singular whenever x and x{sup '} are connected by a null geodesic, and apply asymptotic methods to determine the structure of the Green function near the null wave front. We show that the singular part of the Green function undergoes a transition each time the null wave front passes through a caustic point, following a repeating fourfold sequence {delta}({sigma}), 1/{pi}{sigma}, -{delta}({sigma}), -1/{pi}{sigma}, etc., where {sigma} is Synge's world function. The matched-expansion method provides insight into the nonlocal properties of the self-force. We show that the self-force generated by the segment of the worldline lying outside the normal neighborhood is not negligible. We apply the matched-expansion method to compute the scalar self-force acting on a static particle on the Nariai spacetime, and validate against an alternative method, obtaining agreement to six decimal places. We conclude with a discussion of the implications for wave propagation and self-force calculations. On black hole spacetimes, any expansion of the Green function in quasinormal modes must be augmented by a branch-cut integral. Nevertheless, we expect the Green function in Schwarzschild spacetime to inherit certain key features, such as a fourfold singular structure manifesting itself through the asymptotic behavior of quasinormal modes. In this way, the Nariai spacetime provides a fertile testing ground for developing insight into the nonlocal part of the self-force on black hole spacetimes.« less

[Comparison of three stand-level biomass estimation methods].

PubMed

Dong, Li Hu; Li, Feng Ri

2016-12-01

At present, the forest biomass methods of regional scale attract most of attention of the researchers, and developing the stand-level biomass model is popular. Based on the forestry inventory data of larch plantation (Larix olgensis) in Jilin Province, we used non-linear seemly unrelated regression (NSUR) to estimate the parameters in two additive system of stand-level biomass equations, i.e., stand-level biomass equations including the stand variables and stand biomass equations including the biomass expansion factor (i.e., Model system 1 and Model system 2), listed the constant biomass expansion factor for larch plantation and compared the prediction accuracy of three stand-level biomass estimation methods. The results indicated that for two additive system of biomass equations, the adjusted coefficient of determination (R a 2 ) of the total and stem equations was more than 0.95, the root mean squared error (RMSE), the mean prediction error (MPE) and the mean absolute error (MAE) were smaller. The branch and foliage biomass equations were worse than total and stem biomass equations, and the adjusted coefficient of determination (R a 2 ) was less than 0.95. The prediction accuracy of a constant biomass expansion factor was relatively lower than the prediction accuracy of Model system 1 and Model system 2. Overall, although stand-level biomass equation including the biomass expansion factor belonged to the volume-derived biomass estimation method, and was different from the stand biomass equations including stand variables in essence, but the obtained prediction accuracy of the two methods was similar. The constant biomass expansion factor had the lower prediction accuracy, and was inappropriate. In addition, in order to make the model parameter estimation more effective, the established stand-level biomass equations should consider the additivity in a system of all tree component biomass and total biomass equations.

Salvage rapid maxillary expansion for the relapse of maxillary transverse expansion after Le Fort I with parasagittal osteotomy

PubMed Central

2015-01-01

Maxillary transverse deficiency is one of the most common deformities among occlusal discrepancies. Typical surgical methods are segmental Le Fort I osteotomy and surgically-assisted rapid maxillary expansion (SARME). This patient underwent a parasagittal split with a Le Fort I osteotomy to correct transverse maxillary deficiency. During follow-up, early transverse relapse occurred and rapid maxillary expansion (RME) application with removal of the fixative plate on the constricted side was able to regain the dimension again. RME application may be appropriate salvage therapy for such a case. PMID:25922822

Efficient algorithms for analyzing the singularly perturbed boundary value problems of fractional order

NASA Astrophysics Data System (ADS)

Sayevand, K.; Pichaghchi, K.

2018-04-01

In this paper, we were concerned with the description of the singularly perturbed boundary value problems in the scope of fractional calculus. We should mention that, one of the main methods used to solve these problems in classical calculus is the so-called matched asymptotic expansion method. However we shall note that, this was not achievable via the existing classical definitions of fractional derivative, because they do not obey the chain rule which one of the key elements of the matched asymptotic expansion method. In order to accommodate this method to fractional derivative, we employ a relatively new derivative so-called the local fractional derivative. Using the properties of local fractional derivative, we extend the matched asymptotic expansion method to the scope of fractional calculus and introduce a reliable new algorithm to develop approximate solutions of the singularly perturbed boundary value problems of fractional order. In the new method, the original problem is partitioned into inner and outer solution equations. The reduced equation is solved with suitable boundary conditions which provide the terminal boundary conditions for the boundary layer correction. The inner solution problem is next solved as a solvable boundary value problem. The width of the boundary layer is approximated using appropriate resemblance function. Some theoretical results are established and proved. Some illustrating examples are solved and the results are compared with those of matched asymptotic expansion method and homotopy analysis method to demonstrate the accuracy and efficiency of the method. It can be observed that, the proposed method approximates the exact solution very well not only in the boundary layer, but also away from the layer.

On Complicated Expansions of Solutions to ODES

NASA Astrophysics Data System (ADS)

Bruno, A. D.

2018-03-01

Polynomial ordinary differential equations are studied by asymptotic methods. The truncated equation associated with a vertex or a nonhorizontal edge of their polygon of the initial equation is assumed to have a solution containing the logarithm of the independent variable. It is shown that, under very weak constraints, this nonpower asymptotic form of solutions to the original equation can be extended to an asymptotic expansion of these solutions. This is an expansion in powers of the independent variable with coefficients being Laurent series in decreasing powers of the logarithm. Such expansions are sometimes called psi-series. Algorithms for such computations are described. Six examples are given. Four of them are concern with Painlevé equations. An unexpected property of these expansions is revealed.

Study of travelling wave solutions for some special-type nonlinear evolution equations

NASA Astrophysics Data System (ADS)

Song, Junquan; Hu, Lan; Shen, Shoufeng; Ma, Wen-Xiu

2018-07-01

The tanh-function expansion method has been improved and used to construct travelling wave solutions of the form U={\\sum }j=0n{a}j{\\tanh }jξ for some special-type nonlinear evolution equations, which have a variety of physical applications. The positive integer n can be determined by balancing the highest order linear term with the nonlinear term in the evolution equations. We improve the tanh-function expansion method with n = 0 by introducing a new transform U=-W\\prime (ξ )/{W}2. A nonlinear wave equation with source terms, and mKdV-type equations, are considered in order to show the effectiveness of the improved scheme. We also propose the tanh-function expansion method of implicit function form, and apply it to a Harry Dym-type equation as an example.

Utilizing T-cell Activation Signals 1, 2, and 3 for Tumor-infiltrating Lymphocytes (TIL) Expansion: The Advantage Over the Sole Use of Interleukin-2 in Cutaneous and Uveal Melanoma.

PubMed

Tavera, René J; Forget, Marie-Andrée; Kim, Young Uk; Sakellariou-Thompson, Donastas; Creasy, Caitlin A; Bhatta, Ankit; Fulbright, Orenthial J; Ramachandran, Renjith; Thorsen, Shawne T; Flores, Esteban; Wahl, Arely; Gonzalez, Audrey M; Toth, Christopher; Wardell, Seth; Mansaray, Rahmatu; Radvanyi, Laszlo G; Gombos, Dan S; Patel, Sapna P; Hwu, Patrick; Amaria, Rodabe N; Bernatchez, Chantale; Haymaker, Cara

2018-05-11

In this study, we address one of the major critiques for tumor-infiltrating lymphocyte (TIL) therapy-the time needed for proper expansion of a suitable product. We postulated that T-cell receptor activation in the first phase of expansion combined with an agonistic stimulation of CD137/4-1BB and interleukin-2 would favor preferential expansion of CD8 TIL. Indeed, this novel 3-signal approach for optimal T-cell activation resulted in faster and more consistent expansion of CD8CD3 TIL. This new method allowed for successful expansion of TIL from cutaneous and uveal melanoma tumors in 100% of the cultures in <3 weeks. Finally, providing the 3 signals attributed to optimal T-cell activation led to expansion of TIL capable of recognizing their tumor counterpart in cutaneous and uveal melanoma. This new methodology for the initial phase of TIL expansion brings a new opportunity for translation of TIL therapy in challenging malignancies such as uveal melanoma.

A Lagrangian discontinuous Galerkin hydrodynamic method

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

Liu, Xiaodong; Morgan, Nathaniel Ray; Burton, Donald E.

Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for solving the two-dimensional gas dynamic equations on unstructured hybrid meshes. The physical conservation laws for the momentum and total energy are discretized using a DG method based on linear Taylor expansions. Three different approaches are investigated for calculating the density variation over the element. The first approach evolves a Taylor expansion of the specific volume field. The second approach follows certain finite element methods and uses the strong mass conservation to calculate the density field at a location inside the element or on the element surface. The thirdmore » approach evolves a Taylor expansion of the density field. The nodal velocity, and the corresponding forces, are explicitly calculated by solving a multidirectional approximate Riemann problem. An effective limiting strategy is presented that ensures monotonicity of the primitive variables. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. Results from a suite of test problems are presented to demonstrate the robustness and expected second-order accuracy of this new method.« less

A Lagrangian discontinuous Galerkin hydrodynamic method

DOE PAGES

Liu, Xiaodong; Morgan, Nathaniel Ray; Burton, Donald E.

2017-12-11

Here, we present a new Lagrangian discontinuous Galerkin (DG) hydrodynamic method for solving the two-dimensional gas dynamic equations on unstructured hybrid meshes. The physical conservation laws for the momentum and total energy are discretized using a DG method based on linear Taylor expansions. Three different approaches are investigated for calculating the density variation over the element. The first approach evolves a Taylor expansion of the specific volume field. The second approach follows certain finite element methods and uses the strong mass conservation to calculate the density field at a location inside the element or on the element surface. The thirdmore » approach evolves a Taylor expansion of the density field. The nodal velocity, and the corresponding forces, are explicitly calculated by solving a multidirectional approximate Riemann problem. An effective limiting strategy is presented that ensures monotonicity of the primitive variables. This new Lagrangian DG hydrodynamic method conserves mass, momentum, and total energy. Results from a suite of test problems are presented to demonstrate the robustness and expected second-order accuracy of this new method.« less

On analyticity of linear waves scattered by a layered medium

NASA Astrophysics Data System (ADS)

Nicholls, David P.

2017-10-01

The scattering of linear waves by periodic structures is a crucial phenomena in many branches of applied physics and engineering. In this paper we establish rigorous analytic results necessary for the proper numerical analysis of a class of High-Order Perturbation of Surfaces methods for simulating such waves. More specifically, we prove a theorem on existence and uniqueness of solutions to a system of partial differential equations which model the interaction of linear waves with a multiply layered periodic structure in three dimensions. This result provides hypotheses under which a rigorous numerical analysis could be conducted for recent generalizations to the methods of Operator Expansions, Field Expansions, and Transformed Field Expansions.

Thermal expansion coefficient determination of polylactic acid using digital image correlation

NASA Astrophysics Data System (ADS)

Botean, Adrian-Ioan

2018-02-01

This paper aims determining the linear thermal expansion coefficient (CTE) of polylactic acid (PLA) using an optical method for measuring deformations called digital image correlation method (DIC). Because PLA is often used in making many pieces with 3D printing technology, it is opportune to know this coefficient to obtain a higher degree of precision in the construction of parts and to monitor deformations when these parts are subjected to a thermal gradient. Are used two PLA discs with 20 and 40% degree of filling. In parallel with this approach was determined the linear thermal expansion coefficient (CTE) for the copper cylinder on the surface of which are placed the two discs of PLA.

Min-Max Spaces and Complexity Reduction in Min-Max Expansions

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

Gaubert, Stephane, E-mail: Stephane.Gaubert@inria.fr; McEneaney, William M., E-mail: wmceneaney@ucsd.edu

2012-06-15

Idempotent methods have been found to be extremely helpful in the numerical solution of certain classes of nonlinear control problems. In those methods, one uses the fact that the value function lies in the space of semiconvex functions (in the case of maximizing controllers), and approximates this value using a truncated max-plus basis expansion. In some classes, the value function is actually convex, and then one specifically approximates with suprema (i.e., max-plus sums) of affine functions. Note that the space of convex functions is a max-plus linear space, or moduloid. In extending those concepts to game problems, one finds amore » different function space, and different algebra, to be appropriate. Here we consider functions which may be represented using infima (i.e., min-max sums) of max-plus affine functions. It is natural to refer to the class of functions so represented as the min-max linear space (or moduloid) of max-plus hypo-convex functions. We examine this space, the associated notion of duality and min-max basis expansions. In using these methods for solution of control problems, and now games, a critical step is complexity-reduction. In particular, one needs to find reduced-complexity expansions which approximate the function as well as possible. We obtain a solution to this complexity-reduction problem in the case of min-max expansions.« less

Data availability and feasibility of various techniques to predict response to volume expansion in critically ill patients

PubMed Central

Lanspa, Michael J.; Briggs, Benjamin J.; Hirshberg, Eliotte L.; Pratt, Cristina M.; Grissom, Colin K.; Brown, Samuel M.

2017-01-01

Objective: The accuracy of various techniques to predict response to volume expansion in shock has been studied, but less well known is how feasible these techniques are in the ICU. Methods: This is a prospective observation single-center study of inpatients from a mixed profile ICU who received volume expansion. At time of volume expansion, we determined whether a particular technique to predict response was feasible, according to rules developed from available literature and nurse assessment. Results: We studied 214 volume expansions in 97 patients. The most feasible technique was central venous pressure (50%), followed by vena cava collapsibility, (47%) passive leg raise (42%), and stroke volume variation (22%). Aortic velocity variation, and pulse pressure variation, and were rarely feasible (1% each). In 37% of volume expansions, no technique that we assessed was feasible. Conclusions: Techniques to predict response to volume expansion are infeasible in many patients in shock. PMID:28971030

Applicability of the polynomial chaos expansion method for personalization of a cardiovascular pulse wave propagation model.

PubMed

Huberts, W; Donders, W P; Delhaas, T; van de Vosse, F N

2014-12-01

Patient-specific modeling requires model personalization, which can be achieved in an efficient manner by parameter fixing and parameter prioritization. An efficient variance-based method is using generalized polynomial chaos expansion (gPCE), but it has not been applied in the context of model personalization, nor has it ever been compared with standard variance-based methods for models with many parameters. In this work, we apply the gPCE method to a previously reported pulse wave propagation model and compare the conclusions for model personalization with that of a reference analysis performed with Saltelli's efficient Monte Carlo method. We furthermore differentiate two approaches for obtaining the expansion coefficients: one based on spectral projection (gPCE-P) and one based on least squares regression (gPCE-R). It was found that in general the gPCE yields similar conclusions as the reference analysis but at much lower cost, as long as the polynomial metamodel does not contain unnecessary high order terms. Furthermore, the gPCE-R approach generally yielded better results than gPCE-P. The weak performance of the gPCE-P can be attributed to the assessment of the expansion coefficients using the Smolyak algorithm, which might be hampered by the high number of model parameters and/or by possible non-smoothness in the output space. Copyright © 2014 John Wiley & Sons, Ltd.

A forward-advancing wave expansion method for numerical solution of large-scale sound propagation problems

NASA Astrophysics Data System (ADS)

Rolla, L. Barrera; Rice, H. J.

2006-09-01

In this paper a "forward-advancing" field discretization method suitable for solving the Helmholtz equation in large-scale problems is proposed. The forward wave expansion method (FWEM) is derived from a highly efficient discretization procedure based on interpolation of wave functions known as the wave expansion method (WEM). The FWEM computes the propagated sound field by means of an exclusively forward advancing solution, neglecting the backscattered field. It is thus analogous to methods such as the (one way) parabolic equation method (PEM) (usually discretized using standard finite difference or finite element methods). These techniques do not require the inversion of large system matrices and thus enable the solution of large-scale acoustic problems where backscatter is not of interest. Calculations using FWEM are presented for two propagation problems and comparisons to data computed with analytical and theoretical solutions and show this forward approximation to be highly accurate. Examples of sound propagation over a screen in upwind and downwind refracting atmospheric conditions at low nodal spacings (0.2 per wavelength in the propagation direction) are also included to demonstrate the flexibility and efficiency of the method.

Cylinder expansion test and gas gun experiment comparison

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

Harrier, Danielle

This is a summer internship presentation by the Hydro Working Group at Los Alamos National Laboratory (LANL) and goes into detail about their cylinder expansion test and gas gun experiment comparison. Specifically, the gas gun experiment is detailed along with applications, the cylinder expansion test is detailed along with applications, there is a comparison of the methods with pros and cons and limitations listed, the summer project is detailed, and future work is talked about.

The Shock and Vibration Digest, Volume 16, Number 10

DTIC Science & Technology

1984-10-01

shaped, arid a general polygonal-shaped membrane Fourier expansion -collocation method and the finite without symmetry They also derived, with the help...geometry is not applicable; therefore, a Fourier sine series expansion technique. The meth- not much work on the dynamic behavior of skew- od was applied...particular m.-de are obtained. This normal mode expansion form of deflection surface. The stability of motion approach has recently been used in a series of

The Impact of the Iowa Franchise Law on Restaurant Franchisor Expansion Strategy,

DTIC Science & Technology

1997-06-18

The enormous success of franchising as an expansion instrument has resulted in a franchising boom over the past few decades. In response to the...success of franchising as a business expansion method and the subsequent complaints by unsuccessful or defrauded franchisees, legislation was enacted at...the federal and state level to attempt to prevent franchisor abuses. The 1992 Iowa Franchise Law has been called the most controversial and restrictive

Products of composite operators in the exact renormalization group formalism

NASA Astrophysics Data System (ADS)

Pagani, C.; Sonoda, H.

2018-02-01

We discuss a general method of constructing the products of composite operators using the exact renormalization group formalism. Considering mainly the Wilson action at a generic fixed point of the renormalization group, we give an argument for the validity of short-distance expansions of operator products. We show how to compute the expansion coefficients by solving differential equations, and test our method with some simple examples.

A robust and efficient stepwise regression method for building sparse polynomial chaos expansions

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

Abraham, Simon, E-mail: Simon.Abraham@ulb.ac.be; Raisee, Mehrdad; Ghorbaniasl, Ghader

2017-03-01

Polynomial Chaos (PC) expansions are widely used in various engineering fields for quantifying uncertainties arising from uncertain parameters. The computational cost of classical PC solution schemes is unaffordable as the number of deterministic simulations to be calculated grows dramatically with the number of stochastic dimension. This considerably restricts the practical use of PC at the industrial level. A common approach to address such problems is to make use of sparse PC expansions. This paper presents a non-intrusive regression-based method for building sparse PC expansions. The most important PC contributions are detected sequentially through an automatic search procedure. The variable selectionmore » criterion is based on efficient tools relevant to probabilistic method. Two benchmark analytical functions are used to validate the proposed algorithm. The computational efficiency of the method is then illustrated by a more realistic CFD application, consisting of the non-deterministic flow around a transonic airfoil subject to geometrical uncertainties. To assess the performance of the developed methodology, a detailed comparison is made with the well established LAR-based selection technique. The results show that the developed sparse regression technique is able to identify the most significant PC contributions describing the problem. Moreover, the most important stochastic features are captured at a reduced computational cost compared to the LAR method. The results also demonstrate the superior robustness of the method by repeating the analyses using random experimental designs.« less

Exact solutions for STO and (3+1)-dimensional KdV-ZK equations using (G‧/G2) -expansion method

NASA Astrophysics Data System (ADS)

Bibi, Sadaf; Mohyud-Din, Syed Tauseef; Ullah, Rahmat; Ahmed, Naveed; Khan, Umar

This article deals with finding some exact solutions of nonlinear fractional differential equations (NLFDEs) by applying a relatively new method known as (G‧/G2) -expansion method. Solutions of space-time fractional Sharma-Tasso-Olever (STO) equation of fractional order and (3+1)-dimensional KdV-Zakharov Kuznetsov (KdV-ZK) equation of fractional order are reckoned to demonstrate the validity of this method. The fractional derivative version of modified Riemann-Liouville, linked with Fractional complex transform is employed to transform fractional differential equations into the corresponding ordinary differential equations.

F-Expansion Method and New Exact Solutions of the Schrödinger-KdV Equation

PubMed Central

Filiz, Ali; Ekici, Mehmet; Sonmezoglu, Abdullah

2014-01-01

F-expansion method is proposed to seek exact solutions of nonlinear evolution equations. With the aid of symbolic computation, we choose the Schrödinger-KdV equation with a source to illustrate the validity and advantages of the proposed method. A number of Jacobi-elliptic function solutions are obtained including the Weierstrass-elliptic function solutions. When the modulus m of Jacobi-elliptic function approaches to 1 and 0, soliton-like solutions and trigonometric-function solutions are also obtained, respectively. The proposed method is a straightforward, short, promising, and powerful method for the nonlinear evolution equations in mathematical physics. PMID:24672327

F-expansion method and new exact solutions of the Schrödinger-KdV equation.

PubMed

Filiz, Ali; Ekici, Mehmet; Sonmezoglu, Abdullah

2014-01-01

F-expansion method is proposed to seek exact solutions of nonlinear evolution equations. With the aid of symbolic computation, we choose the Schrödinger-KdV equation with a source to illustrate the validity and advantages of the proposed method. A number of Jacobi-elliptic function solutions are obtained including the Weierstrass-elliptic function solutions. When the modulus m of Jacobi-elliptic function approaches to 1 and 0, soliton-like solutions and trigonometric-function solutions are also obtained, respectively. The proposed method is a straightforward, short, promising, and powerful method for the nonlinear evolution equations in mathematical physics.

Series: Utilization of Differential Equations and Methods for Solving Them in Medical Physics (4).

PubMed

Murase, Kenya

2016-01-01

Partial differential equations are often used in the field of medical physics. In this (final) issue, the methods for solving the partial differential equations were introduced, which include separation of variables, integral transform (Fourier and Fourier-sine transforms), Green's function, and series expansion methods. Some examples were also introduced, in which the integral transform and Green's function methods were applied to solving Pennes' bioheat transfer equation and the Fourier series expansion method was applied to Navier-Stokes equation for analyzing the wall shear stress in blood vessels.Finally, the author hopes that this series will be helpful for people who engage in medical physics.

Expansion patterns and parallaxes for planetary nebulae

NASA Astrophysics Data System (ADS)

Schönberner, D.; Balick, B.; Jacob, R.

2018-02-01

Aims: We aim to determine individual distances to a small number of rather round, quite regularly shaped planetary nebulae by combining their angular expansion in the plane of the sky with a spectroscopically measured expansion along the line of sight. Methods: We combined up to three epochs of Hubble Space Telescope imaging data and determined the angular proper motions of rim and shell edges and of other features. These results are combined with measured expansion speeds to determine individual distances by assuming that line of sight and sky-plane expansions are equal. We employed 1D radiation-hydrodynamics simulations of nebular evolution to correct for the difference between the spectroscopically measured expansion velocities of rim and shell and of their respective shock fronts. Results: Rim and shell are two independently expanding entities, driven by different physical mechanisms, although their model-based expansion timescales are quite similar. We derive good individual distances for 15 objects, and the main results are as follows: (i) distances derived from rim and shell agree well; (ii) comparison with the statistical distances in the literature gives reasonable agreement; (iii) our distances disagree with those derived by spectroscopic methods; (iv) central-star "plateau" luminosities range from about 2000 L⊙ to well below 10 000 L⊙, with a mean value at about 5000 L⊙, in excellent agreement with other samples of known distance (Galactic bulge, Magellanic Clouds, and K648 in the globular cluster M 15); (v) the central-star mass range is rather restricted: from about 0.53 to about 0.56 M⊙, with a mean value of 0.55 M⊙. Conclusions: The expansion measurements of nebular rim and shell edges confirm the predictions of radiation-hydrodynamics simulations and offer a reliable method for the evaluation of distances to suited objects. Results of this paper are based on observations made with the NASA/ESA Hubble Space Telescope in Cycle 16 (GO11122) and older data obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

[Assessment on the ecological suitability in Zhuhai City, Guangdong, China, based on minimum cumulative resistance model].

PubMed

Li, Jian-fei; Li, Lin; Guo, Luo; Du, Shi-hong

2016-01-01

Urban landscape has the characteristics of spatial heterogeneity. Because the expansion process of urban constructive or ecological land has different resistance values, the land unit stimulates and promotes the expansion of ecological land with different intensity. To compare the effect of promoting and hindering functions in the same land unit, we firstly compared the minimum cumulative resistance value of promoting and hindering functions, and then looked for the balance of two landscape processes under the same standard. According to the ecology principle of minimum limit factor, taking the minimum cumulative resistance analysis method under two expansion processes as the evaluation method of urban land ecological suitability, this research took Zhuhai City as the study area to estimate urban ecological suitability by relative evaluation method with remote sensing image, field survey, and statistics data. With the support of ArcGIS, five types of indicators on landscape types, ecological value, soil erosion sensitivity, sensitivity of geological disasters, and ecological function were selected as input parameters in the minimum cumulative resistance model to compute urban ecological suitability. The results showed that the ecological suitability of the whole Zhuhai City was divided into five levels: constructive expansion prohibited zone (10.1%), constructive expansion restricted zone (32.9%), key construction zone (36.3%), priority development zone (2.3%), and basic cropland (18.4%). Ecological suitability of the central area of Zhuhai City was divided into four levels: constructive expansion prohibited zone (11.6%), constructive expansion restricted zone (25.6%), key construction zone (52.4%), priority development zone (10.4%). Finally, we put forward the sustainable development framework of Zhuhai City according to the research conclusion. On one hand, the government should strictly control the development of the urban center area. On the other hand, the secondary urban center area such as Junchang and Doumen need improve the public infrastructure to relieve the imbalance between eastern and western development in Zhuhai City.

Goal-Oriented Probability Density Function Methods for Uncertainty Quantification

DTIC Science & Technology

2015-12-11

approximations or data-driven approaches. We investigated the accuracy of analytical tech- niques based Kubo -Van Kampen operator cumulant expansions for...analytical techniques based Kubo -Van Kampen operator cumulant expansions for Langevin equations driven by fractional Brownian motion and other noises

Expansion method in secondary total ear reconstruction for undesirable reconstructed ear.

PubMed

Liu, Tun; Hu, Jintian; Zhou, Xu; Zhang, Qingguo

2014-09-01

Ear reconstruction by autologous costal cartilage grafting is the most widely applied technique with fewer complications. However, undesirable ear reconstruction brings more problems to plastic surgeons. Some authors resort to free flap or osseointegration technique with prosthetic ear. In this article, we introduce a secondary total ear reconstruction with expanded skin flap method. From July 2010 to April 2012, 7 cases of undesirable ear reconstruction were repaired by tissue expansion method. Procedures including removal of previous cartilage framework, soft tissue expander insertion, and second stage of cartilage framework insertion were performed to each case regarding their local conditions. The follow-up time ranged from 6 months to 2.5 years. All of the cases recovered well with good 3-dimensional forms, symmetrical auriculocephalic angle, and stable fixation. All these evidence showed that this novel expansion method is safe, stable, and less traumatic for secondary total ear reconstruction. With sufficient expanded skin flap and refabricated cartilage framework, lifelike appearance of reconstructed ear could be acquired without causing additional injury.

Automatically finding relevant citations for clinical guideline development.

PubMed

Bui, Duy Duc An; Jonnalagadda, Siddhartha; Del Fiol, Guilherme

2015-10-01

Literature database search is a crucial step in the development of clinical practice guidelines and systematic reviews. In the age of information technology, the process of literature search is still conducted manually, therefore it is costly, slow and subject to human errors. In this research, we sought to improve the traditional search approach using innovative query expansion and citation ranking approaches. We developed a citation retrieval system composed of query expansion and citation ranking methods. The methods are unsupervised and easily integrated over the PubMed search engine. To validate the system, we developed a gold standard consisting of citations that were systematically searched and screened to support the development of cardiovascular clinical practice guidelines. The expansion and ranking methods were evaluated separately and compared with baseline approaches. Compared with the baseline PubMed expansion, the query expansion algorithm improved recall (80.2% vs. 51.5%) with small loss on precision (0.4% vs. 0.6%). The algorithm could find all citations used to support a larger number of guideline recommendations than the baseline approach (64.5% vs. 37.2%, p<0.001). In addition, the citation ranking approach performed better than PubMed's "most recent" ranking (average precision +6.5%, recall@k +21.1%, p<0.001), PubMed's rank by "relevance" (average precision +6.1%, recall@k +14.8%, p<0.001), and the machine learning classifier that identifies scientifically sound studies from MEDLINE citations (average precision +4.9%, recall@k +4.2%, p<0.001). Our unsupervised query expansion and ranking techniques are more flexible and effective than PubMed's default search engine behavior and the machine learning classifier. Automated citation finding is promising to augment the traditional literature search. Copyright © 2015 Elsevier Inc. All rights reserved.

Solving nonlinear evolution equation system using two different methods

NASA Astrophysics Data System (ADS)

Kaplan, Melike; Bekir, Ahmet; Ozer, Mehmet N.

2015-12-01

This paper deals with constructing more general exact solutions of the coupled Higgs equation by using the (G0/G, 1/G)-expansion and (1/G0)-expansion methods. The obtained solutions are expressed by three types of functions: hyperbolic, trigonometric and rational functions with free parameters. It has been shown that the suggested methods are productive and will be used to solve nonlinear partial differential equations in applied mathematics and engineering. Throughout the paper, all the calculations are made with the aid of the Maple software.

A Unified Method of Finding Laplace Transforms, Fourier Transforms, and Fourier Series. [and] An Inversion Method for Laplace Transforms, Fourier Transforms, and Fourier Series. Integral Transforms and Series Expansions. Modules and Monographs in Undergraduate Mathematics and Its Applications Project. UMAP Units 324 and 325.

ERIC Educational Resources Information Center

Grimm, C. A.

This document contains two units that examine integral transforms and series expansions. In the first module, the user is expected to learn how to use the unified method presented to obtain Laplace transforms, Fourier transforms, complex Fourier series, real Fourier series, and half-range sine series for given piecewise continuous functions. In…

Separable Ernst-Shakin-Thaler expansions of local potentials

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

Bund, G.W.

The boundary condition Ernst-Shakin-Thaler method, introduced previously to generate separable expansions of local potentials of finite range, is applied to the study of the triplet s-wave Malfliet-Tjon potential. The effect of varying the radius where the boundary condition is applied on the T matrix is analyzed. Further, we compare the convergence of the n-d scattering cross sections in the quartet state below the breakup threshold for expansions corresponding to two different boundaries.

Heat transfer head for a Stirling cycle machine

NASA Technical Reports Server (NTRS)

Emigh, Stuart G. (Inventor); Noble, Jack E. (Inventor); Lehmann, Gregory A. (Inventor)

1991-01-01

A common heat acceptor is provided between opposed displacers in a Stirling cycle machine. It includes two sets of open channels in separate fluid communications with the expansion spaces of the receptive cyclinders. The channels confine movement of working fluid in separate paths that extend between the expansion space of one cylinder and the compression space of the other. The method for operating the machine involves alternatively directing working fluid from the expansion space of each cylinder in a fluid path leading to the compression space of the other cylinder and from the compression space of each cylinder in a fluid path leading to the expansion space of the other cylinder.

Off-diagonal expansion quantum Monte Carlo

NASA Astrophysics Data System (ADS)

Albash, Tameem; Wagenbreth, Gene; Hen, Itay

2017-12-01

We propose a Monte Carlo algorithm designed to simulate quantum as well as classical systems at equilibrium, bridging the algorithmic gap between quantum and classical thermal simulation algorithms. The method is based on a decomposition of the quantum partition function that can be viewed as a series expansion about its classical part. We argue that the algorithm not only provides a theoretical advancement in the field of quantum Monte Carlo simulations, but is optimally suited to tackle quantum many-body systems that exhibit a range of behaviors from "fully quantum" to "fully classical," in contrast to many existing methods. We demonstrate the advantages, sometimes by orders of magnitude, of the technique by comparing it against existing state-of-the-art schemes such as path integral quantum Monte Carlo and stochastic series expansion. We also illustrate how our method allows for the unification of quantum and classical thermal parallel tempering techniques into a single algorithm and discuss its practical significance.

Solution of Linearized Drift Kinetic Equations in Neoclassical Transport Theory by the Method of Matched Asymptotic Expansions

NASA Astrophysics Data System (ADS)

Wong, S. K.; Chan, V. S.; Hinton, F. L.

2001-10-01

The classic solution of the linearized drift kinetic equations in neoclassical transport theory for large-aspect-ratio tokamak flux-surfaces relies on the variational principle and the choice of ``localized" distribution functions as trialfunctions.(M.N. Rosenbluth, et al., Phys. Fluids 15) (1972) 116. Somewhat unclear in this approach are the nature and the origin of the ``localization" and whether the results obtained represent the exact leading terms in an asymptotic expansion int he inverse aspect ratio. Using the method of matched asymptotic expansions, we were able to derive the leading approximations to the distribution functions and demonstrated the asymptotic exactness of the existing results. The method is also applied to the calculation of angular momentum transport(M.N. Rosenbluth, et al., Plasma Phys. and Contr. Nucl. Fusion Research, 1970, Vol. 1 (IAEA, Vienna, 1971) p. 495.) and the current driven by electron cyclotron waves.

Devolatilization Analysis in a Twin Screw Extruder by using the Flow Analysis Network (FAN) Method

NASA Astrophysics Data System (ADS)

Tomiyama, Hideki; Takamoto, Seiji; Shintani, Hiroaki; Inoue, Shigeki

We derived the theoretical formulas for three mechanisms of devolatilization in a twin screw extruder. These are flash, surface refreshment and forced expansion. The method for flash devolatilization is based on the equation of equilibrium concentration which shows that volatiles break off from polymer when they are relieved from high pressure condition. For surface refreshment devolatilization, we applied Latinen's model to allow estimation of polymer behavior in the unfilled screw conveying condition. Forced expansion devolatilization is based on the expansion theory in which foams are generated under reduced pressure and volatiles are diffused on the exposed surface layer after mixing with the injected devolatilization agent. Based on these models, we developed the simulation software of twin-screw extrusion by the FAN method and it allows us to quantitatively estimate volatile concentration and polymer temperature with a high accuracy in the actual multi-vent extrusion process for LDPE + n-hexane.

Off-diagonal expansion quantum Monte Carlo.

PubMed

Albash, Tameem; Wagenbreth, Gene; Hen, Itay

2017-12-01

We propose a Monte Carlo algorithm designed to simulate quantum as well as classical systems at equilibrium, bridging the algorithmic gap between quantum and classical thermal simulation algorithms. The method is based on a decomposition of the quantum partition function that can be viewed as a series expansion about its classical part. We argue that the algorithm not only provides a theoretical advancement in the field of quantum Monte Carlo simulations, but is optimally suited to tackle quantum many-body systems that exhibit a range of behaviors from "fully quantum" to "fully classical," in contrast to many existing methods. We demonstrate the advantages, sometimes by orders of magnitude, of the technique by comparing it against existing state-of-the-art schemes such as path integral quantum Monte Carlo and stochastic series expansion. We also illustrate how our method allows for the unification of quantum and classical thermal parallel tempering techniques into a single algorithm and discuss its practical significance.

Controlled Expansion of Supercritical Solution: A Robust Method to Produce Pure Drug Nanoparticles With Narrow Size-Distribution.

PubMed

Pessi, Jenni; Lassila, Ilkka; Meriläinen, Antti; Räikkönen, Heikki; Hæggström, Edward; Yliruusi, Jouko

2016-08-01

We introduce a robust, stable, and reproducible method to produce nanoparticles based on expansion of supercritical solutions using carbon dioxide as a solvent. The method, controlled expansion of supercritical solution (CESS), uses controlled mass transfer, flow, pressure reduction, and particle collection in dry ice. CESS offers control over the crystallization process as the pressure in the system is reduced according to a specific profile. Particle formation takes place before the exit nozzle, and condensation is the main mechanism for postnucleation particle growth. A 2-step gradient pressure reduction is used to prevent Mach disk formation and particle growth by coagulation. Controlled particle growth keeps the production process stable. With CESS, we produced piroxicam nanoparticles, 60 mg/h, featuring narrow size distribution (176 ± 53 nm). Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Evaluation on expansive performance of the expansive soil using electrical responses

NASA Astrophysics Data System (ADS)

Chu, Ya; Liu, Songyu; Bate, Bate; Xu, Lei

2018-01-01

Light structures, such as highways and railroads, built on expansive soils are prone to damages from the swelling of their underlain soil layers. Considerable amount of research has been conducted to characterize the swelling properties of expansive soils. Current swell characterization models, however, are limited by lack of standardized tests. Electrical methods are non-destructive, and are faster and less expensive than the traditional geotechnical methods. Therefore, geo-electrical methods are attractive for defining soil characteristics, including the swelling behavior. In this study, comprehensive laboratory experiments were undertaken to measure the free swelling and electrical resistivity of the mixtures of commercial kaolinite and bentonite. The electrical conductivity of kaolinite-bentonite mixtures was measured by a self-developed four-electrode soil resistivity box. Increasing the free swelling rate of the kaolinite-bentonite mixtures (0.72 to 1 of porosity of soils samples) led to a reduction in the electrical resistivity and an increase in conductivity. A unique relationship between free swelling rate and normalized surface conductivity was constructed for expensive soils by eliminating influences of porosity and m exponent. Therefore, electrical response measurement can be used to characterize the free swelling rate of expensive soils.

Combining the Complete Active Space Self-Consistent Field Method and the Full Configuration Interaction Quantum Monte Carlo within a Super-CI Framework, with Application to Challenging Metal-Porphyrins.

PubMed

Li Manni, Giovanni; Smart, Simon D; Alavi, Ali

2016-03-08

A novel stochastic Complete Active Space Self-Consistent Field (CASSCF) method has been developed and implemented in the Molcas software package. A two-step procedure is used, in which the CAS configuration interaction secular equations are solved stochastically with the Full Configuration Interaction Quantum Monte Carlo (FCIQMC) approach, while orbital rotations are performed using an approximated form of the Super-CI method. This new method does not suffer from the strong combinatorial limitations of standard MCSCF implementations using direct schemes and can handle active spaces well in excess of those accessible to traditional CASSCF approaches. The density matrix formulation of the Super-CI method makes this step independent of the size of the CI expansion, depending exclusively on one- and two-body density matrices with indices restricted to the relatively small number of active orbitals. No sigma vectors need to be stored in memory for the FCIQMC eigensolver--a substantial gain in comparison to implementations using the Davidson method, which require three or more vectors of the size of the CI expansion. Further, no orbital Hessian is computed, circumventing limitations on basis set expansions. Like the parent FCIQMC method, the present technique is scalable on massively parallel architectures. We present in this report the method and its application to the free-base porphyrin, Mg(II) porphyrin, and Fe(II) porphyrin. In the present study, active spaces up to 32 electrons and 29 orbitals in orbital expansions containing up to 916 contracted functions are treated with modest computational resources. Results are quite promising even without accounting for the correlation outside the active space. The systems here presented clearly demonstrate that large CASSCF calculations are possible via FCIQMC-CASSCF without limitations on basis set size.

Systematic Expansion of Active Spaces beyond the CASSCF Limit: A GASSCF/SplitGAS Benchmark Study.

PubMed

Vogiatzis, Konstantinos D; Li Manni, Giovanni; Stoneburner, Samuel J; Ma, Dongxia; Gagliardi, Laura

2015-07-14

The applicability and accuracy of the generalized active space self-consistent field, (GASSCF), and (SplitGAS) methods are presented. The GASSCF method enables the exploration of larger active spaces than with the conventional complete active space SCF, (CASSCF), by fragmentation of a large space into subspaces and by controlling the interspace excitations. In the SplitGAS method, the GAS configuration interaction, CI, expansion is further partitioned in two parts: the principal, which includes the most important configuration state functions, and an extended, containing less relevant but not negligible ones. An effective Hamiltonian is then generated, with the extended part acting as a perturbation to the principal space. Excitation energies of ozone, furan, pyrrole, nickel dioxide, and copper tetrachloride dianion are reported. Various partitioning schemes of the GASSCF and SplitGAS CI expansions are considered and compared with the complete active space followed by second-order perturbation theory, (CASPT2), and multireference CI method, (MRCI), or available experimental data. General guidelines for the optimum applicability of these methods are discussed together with their current limitations.

Numerical stress analysis of the iris tissue induced by pupil expansion: Comparison of commercial devices

PubMed Central

Wang, Xiaofei; Perera, Shamira A.; Girard, Michaël J. A.

2018-01-01

Purpose (1) To use finite element (FE) modelling to estimate local iris stresses (i.e. internal forces) as a result of mechanical pupil expansion; and to (2) compare such stresses as generated from several commercially available expanders (Iris hooks, APX dilator and Malyugin ring) to determine which design and deployment method are most likely to cause iris damage. Methods We used a biofidelic 3-part iris FE model that consisted of the stroma, sphincter and dilator muscles. Our FE model simulated expansion of the pupil from 3 mm to a maximum of 6 mm using the aforementioned pupil expanders, with uniform circular expansion used for baseline comparison. FE-derived stresses, resultant forces and area of final pupil opening were compared across devices for analysis. Results Our FE models demonstrated that the APX dilator generated the highest stresses on the sphincter muscles, (max: 6.446 MPa; average: 5.112 MPa), followed by the iris hooks (max: 5.680 MPa; average: 5.219 MPa), and the Malyugin ring (max: 2.144 MPa; average: 1.575 MPa). Uniform expansion generated the lowest stresses (max: 0.435MPa; average: 0.377 MPa). For pupil expansion, the APX dilator required the highest force (41.22 mN), followed by iris hooks (40.82 mN) and the Malyugin ring (18.56 mN). Conclusion Our study predicted that current pupil expanders exert significantly higher amount of stresses and forces than required during pupil expansion. Our work may serve as a guide for the development and design of next-generation pupil expanders. PMID:29538452

Reduced-Stress Mounting for Thermocouples

NASA Technical Reports Server (NTRS)

Wood, C.

1986-01-01

Mounting accommodates widely different coefficients of thermal expansion. In new method, legs of thermocouple placed in separate n- and p-type arrays. Two arrays contact common heat pipe as source but have separate heatpipe sinks. Net expansion (or contraction) taken up by spring mounting on heat-pipe sinks.

Soft Expansion of Double-Real-Virtual Corrections to Higgs Production at N$^3$LO

DOE PAGES

Anastasiou, Charalampos; Duhr, Claude; Dulat, Falko; ...

2015-05-15

We present methods to compute higher orders in the threshold expansion for the one-loop production of a Higgs boson in association with two partons at hadron colliders. This process contributes to the N 3LO Higgs production cross section beyond the soft-virtual approximation. We use reverse unitarity to expand the phase-space integrals in the small kinematic parameters and to reduce the coefficients of the expansion to a small set of master integrals. We describe two methods for the calculation of the master integrals. The first was introduced for the calculation of the soft triple-real radiation relevant to N 3LO Higgs production.more » The second uses a particular factorization of the three body phase-space measure and the knowledge of the scaling properties of the integral itself. Our result is presented as a Laurent expansion in the dimensional regulator, although some of the master integrals are computed to all orders in this parameter.« less

Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

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

Wang, Jy-An John

To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’smore » vertical displacement soon after the wedge-clad contact resistance is initiated.« less

Method of Liquifying a gas

DOEpatents

Zollinger, William T.; Bingham, Dennis N.; McKellar, Michael G.; Wilding, Bruce M.; Klingler, Kerry M.

2006-02-14

A method of liquefying a gas is disclosed and which includes the steps of pressurizing a liquid; mixing a reactant composition with the pressurized liquid to generate a high pressure gas; supplying the high pressure gas to an expansion engine which produces a gas having a reduced pressure and temperature, and which further generates a power and/or work output; coupling the expansion engine in fluid flowing relation relative to a refrigeration assembly, and wherein the gas having the reduced temperature is provided to the refrigeration assembly; and energizing and/or actuating the refrigeration assembly, at least in part, by supplying the power and/or work output generated by the expansion engine to the refrigeration assembly, the refrigeration assembly further reducing the temperature of the gas to liquefy same.

Predicting Molecular Crystal Properties from First Principles: Finite-Temperature Thermochemistry to NMR Crystallography.

PubMed

Beran, Gregory J O; Hartman, Joshua D; Heit, Yonaton N

2016-11-15

Molecular crystals occur widely in pharmaceuticals, foods, explosives, organic semiconductors, and many other applications. Thanks to substantial progress in electronic structure modeling of molecular crystals, attention is now shifting from basic crystal structure prediction and lattice energy modeling toward the accurate prediction of experimentally observable properties at finite temperatures and pressures. This Account discusses how fragment-based electronic structure methods can be used to model a variety of experimentally relevant molecular crystal properties. First, it describes the coupling of fragment electronic structure models with quasi-harmonic techniques for modeling the thermal expansion of molecular crystals, and what effects this expansion has on thermochemical and mechanical properties. Excellent agreement with experiment is demonstrated for the molar volume, sublimation enthalpy, entropy, and free energy, and the bulk modulus of phase I carbon dioxide when large basis second-order Møller-Plesset perturbation theory (MP2) or coupled cluster theories (CCSD(T)) are used. In addition, physical insight is offered into how neglect of thermal expansion affects these properties. Zero-point vibrational motion leads to an appreciable expansion in the molar volume; in carbon dioxide, it accounts for around 30% of the overall volume expansion between the electronic structure energy minimum and the molar volume at the sublimation point. In addition, because thermal expansion typically weakens the intermolecular interactions, neglecting thermal expansion artificially stabilizes the solid and causes the sublimation enthalpy to be too large at higher temperatures. Thermal expansion also frequently weakens the lower-frequency lattice phonon modes; neglecting thermal expansion causes the entropy of sublimation to be overestimated. Interestingly, the sublimation free energy is less significantly affected by neglecting thermal expansion because the systematic errors in the enthalpy and entropy cancel somewhat. Second, because solid state nuclear magnetic resonance (NMR) plays an increasingly important role in molecular crystal studies, this Account discusses how fragment methods can be used to achieve higher-accuracy chemical shifts in molecular crystals. Whereas widely used plane wave density functional theory models are largely restricted to generalized gradient approximation (GGA) functionals like PBE in practice, fragment methods allow the routine use of hybrid density functionals with only modest increases in computational cost. In extensive molecular crystal benchmarks, hybrid functionals like PBE0 predict chemical shifts with 20-30% higher accuracy than GGAs, particularly for 1 H, 13 C, and 15 N nuclei. Due to their higher sensitivity to polarization effects, 17 O chemical shifts prove slightly harder to predict with fragment methods. Nevertheless, the fragment model results are still competitive with those from GIPAW. The improved accuracy achievable with fragment approaches and hybrid density functionals increases discrimination between different potential assignments of individual shifts or crystal structures, which is critical in NMR crystallography applications. This higher accuracy and greater discrimination are highlighted in application to the solid state NMR of different acetaminophen and testosterone crystal forms.

Second-order singular pertubative theory for gravitational lenses

NASA Astrophysics Data System (ADS)

Alard, C.

2018-03-01

The extension of the singular perturbative approach to the second order is presented in this paper. The general expansion to the second order is derived. The second-order expansion is considered as a small correction to the first-order expansion. Using this approach, it is demonstrated that in practice the second-order expansion is reducible to a first order expansion via a re-definition of the first-order pertubative fields. Even if in usual applications the second-order correction is small the reducibility of the second-order expansion to the first-order expansion indicates a potential degeneracy issue. In general, this degeneracy is hard to break. A useful and simple second-order approximation is the thin source approximation, which offers a direct estimation of the correction. The practical application of the corrections derived in this paper is illustrated by using an elliptical NFW lens model. The second-order pertubative expansion provides a noticeable improvement, even for the simplest case of thin source approximation. To conclude, it is clear that for accurate modelization of gravitational lenses using the perturbative method the second-order perturbative expansion should be considered. In particular, an evaluation of the degeneracy due to the second-order term should be performed, for which the thin source approximation is particularly useful.

The Impact of the ACA's Medicaid Expansion on Hospitals' Uncompensated Care Burden and the Potential Effects of Repeal.

PubMed

Dranove, David; Gartwaite, Craig; Ody, Christopher

2017-05-01

ISSUE: By increasing health insurance coverage, the Affordable Care Act's Medicaid eligibility expansion was also expected to lessen the uncompensated care burden on hospitals. The expansion currently faces an uncertain future. GOAL: To compare the change in hospitals' uncompensated care burden in the 31 states (plus the District of Columbia) that chose to expand Medicaid to the changes in states that did not, and to estimate how these expenses would be affected by repeal or further expansion. METHODS: Analysis of uncompensated care data from Medicare Hospital Cost Reports from 2011 to 2015. FINDINGS AND CONCLUSIONS: Uncompensated care burdens fell sharply in expansion states between 2013 and 2015, from 3.9 percent to 2.3 percent of operating costs. Estimated savings across all hospitals in Medicaid expansion states totaled $6.2 billion. The largest reductions in uncompensated care were found for hospitals in expansion states that care for the highest proportion of low-income and uninsured patients. Legislation that scales back or eliminates Medicaid expansion is likely to expose these safety-net hospitals to large cost increases. Conversely, if the 19 states that chose not to expand Medicaid were to adopt expansion, their uncompensated care costs also would decrease by an estimated $6.2 billion.

Retrieval feedback in MEDLINE.

PubMed Central

Srinivasan, P

1996-01-01

OBJECTIVE: To investigate a new approach for query expansion based on retrieval feedback. The first objective in this study was to examine alternative query-expansion methods within the same retrieval-feedback framework. The three alternatives proposed are: expansion on the MeSH query field alone, expansion on the free-text field alone, and expansion on both the MeSH and the free-text fields. The second objective was to gain further understanding of retrieval feedback by examining possible dependencies on relevant documents during the feedback cycle. DESIGN: Comparative study of retrieval effectiveness using the original unexpanded and the alternative expanded user queries on a MEDLINE test collection of 75 queries and 2,334 MEDLINE citations. MEASUREMENTS: Retrieval effectivenesses of the original unexpanded and the alternative expanded queries were compared using 11-point-average precision scores (11-AvgP). These are averages of precision scores obtained at 11 standard recall points. RESULTS: All three expansion strategies significantly improved the original queries in terms of retrieval effectiveness. Expansion on MeSH alone was equivalent to expansion on both MeSH and the free-text fields. Expansion on the free-text field alone improved the queries significantly less than did the other two strategies. The second part of the study indicated that retrieval-feedback-based expansion yields significant performance improvements independent of the availability of relevant documents for feedback information. CONCLUSIONS: Retrieval feedback offers a robust procedure for query expansion that is most effective for MEDLINE when applied to the MeSH field. PMID:8653452

Use of phase change materials during compressed air expansion for isothermal CAES plants

NASA Astrophysics Data System (ADS)

Castellani, B.; Presciutti, A.; Morini, E.; Filipponi, M.; Nicolini, A.; Rossi, F.

2017-11-01

Compressed air energy storage (CAES) plants are designed to store compressed air into a vessel or in an underground cavern and to expand it in an expansion turbine when energy demand is high. An innovative CAES configuration recently proposed is the isothermal process. Several methods to implement isothermal CAES configuration are under investigation. In this framework, the present paper deals with the experimental testing of phase change materials (PCM) during compressed air expansion phase. The experimental investigation was carried out by means of an apparatus constituted by a compression section, a steel pressure vessel, to which an expansion valve is connected. The initial internal absolute pressure was equal to 5 bar to avoid moisture condensation and the experimental tests were carried out with two paraffin-based PCM amounts (0.05 kg and 0.1 kg). Results show that the temperature change during air expansion decreases with increasing the PCM amount inside the vessel. With the use of PCM during expansions an increase of the expansion work occurs. The increase is included in the range from 9.3% to 18.2%. In every test there is an approach to the isothermal values, which represent the maximum theoretical value of the obtainable expansion work.

Biomechanical effects of maxillary expansion on a patient with cleft palate: A finite element analysis

PubMed Central

Lee, Haofu; Nguyen, Alan; Hong, Christine; Hoang, Paul; Pham, John; Ting, Kang

2017-01-01

Introduction The aims of this study were to evaluate the effects of rapid palatal expansion on the craniofacial skeleton of a patient with unilateral cleft lip and palate (UCLP) and to predict the points of force application for optimal expansion using a 3-dimensional finite element model. Methods A 3-dimensional finite element model of the craniofacial complex with UCLP was generated from spiral computed tomographic scans with imaging software (Mimics, version 13.1; Materialise, Leuven, Belgium). This model was imported into the finite element solver (version 12.0; ANSYS, Canonsburg, Pa) to evaluate transverse expansion forces from rapid palatal expansion. Finite element analysis was performed with transverse expansion to achieve 5 mm of anterolateral expansion of the collapsed minor segment to simulate correction of the anterior crossbite in a patient with UCLP. Results High-stress concentrations were observed at the body of the sphenoid, medial to the orbit, and at the inferior area of the zygomatic process of the maxilla. The craniofacial stress distribution was asymmetric, with higher stress levels on the cleft side. When forces were applied more anteriorly on the collapsed minor segment and more posteriorly on the major segment, there was greater expansion of the anterior region of the minor segment with minimal expansion of the major segment. Conclusions The transverse expansion forces from rapid palatal expansion are distributed to the 3 maxillary buttresses. Finite element analysis is an appropriate tool to study and predict the points of force application for better controlled expansion in patients with UCLP. PMID:27476365

Foam property tests to evaluate the potential for longwall shield dust control.

PubMed

Reed, W R; Beck, T W; Zheng, Y; Klima, S; Driscoll, J

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration's lower coal mine respirable dust standard of 1.5 mg/m 3 . Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control.

Foam property tests to evaluate the potential for longwall shield dust control

PubMed Central

Reed, W.R.; Beck, T.W.; Zheng, Y.; Klima, S.; Driscoll, J.

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration’s lower coal mine respirable dust standard of 1.5 mg/m3. Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control. PMID:29416179

Efficient Manufacturing of Therapeutic Mesenchymal Stromal Cells Using the Quantum Cell Expansion System

PubMed Central

Hanley, Patrick J.; Mei, Zhuyong; Durett, April G.; Cabreira-Harrison, Marie da Graca; Klis, Mariola; Li, Wei; Zhao, Yali; Yang, Bing; Parsha, Kaushik; Mir, Osman; Vahidy, Farhaan; Bloom, Debra; Rice, R. Brent; Hematti, Peiman; Savitz, Sean I; Gee, Adrian P.

2014-01-01

Background The use of bone marrow-derived mesenchymal stromal cells (MSCs) as a cellular therapy for various diseases, such as graft-versus-host-disease, diabetes, ischemic cardiomyopathy, and Crohn's disease has produced promising results in early-phase clinical trials. However, for widespread application and use in later phase studies, manufacture of these cells needs to be cost effective, safe, and reproducible. Current methods of manufacturing in flasks or cell factories are labor-intensive, involve a large number of open procedures, and require prolonged culture times. Methods We evaluated the Quantum Cell Expansion system for the expansion of large numbers of MSCs from unprocessed bone marrow in a functionally closed system and compared the results to a flask-based method currently in clinical trials. Results After only two passages, we were able to expand a mean of 6.6×108 MSCs from 25 mL of bone marrow reproducibly. The mean expansion time was 21 days, and cells obtained were able to differentiate into all three lineages: chondrocytes, osteoblasts, and adipocytes. The Quantum was able to generate the target cell number of 2.0×108 cells in an average of 9-fewer days and in half the number of passages required during flask-based expansion. We estimated the Quantum would involve 133 open procedures versus 54,400 in flasks when manufacturing for a clinical trial. Quantum-expanded MSCs infused into an ischemic stroke rat model were therapeutically active. Discussion The Quantum is a novel method of generating high numbers of MSCs in less time and at lower passages when compared to flasks. In the Quantum, the risk of contamination is substantially reduced due to the substantial decrease in open procedures. PMID:24726657

Method for Expressing Clinical and Statistical Significance of Ocular and Corneal Wavefront Error Aberrations

PubMed Central

Smolek, Michael K.

2011-01-01

Purpose The significance of ocular or corneal aberrations may be subject to misinterpretation whenever eyes with different pupil sizes or the application of different Zernike expansion orders are compared. A method is shown that uses simple mathematical interpolation techniques based on normal data to rapidly determine the clinical significance of aberrations, without concern for pupil and expansion order. Methods Corneal topography (Tomey, Inc.; Nagoya, Japan) from 30 normal corneas was collected and the corneal wavefront error analyzed by Zernike polynomial decomposition into specific aberration types for pupil diameters of 3, 5, 7, and 10 mm and Zernike expansion orders of 6, 8, 10 and 12. Using this 4×4 matrix of pupil sizes and fitting orders, best-fitting 3-dimensional functions were determined for the mean and standard deviation of the RMS error for specific aberrations. The functions were encoded into software to determine the significance of data acquired from non-normal cases. Results The best-fitting functions for 6 types of aberrations were determined: defocus, astigmatism, prism, coma, spherical aberration, and all higher-order aberrations. A clinical screening method of color-coding the significance of aberrations in normal, postoperative LASIK, and keratoconus cases having different pupil sizes and different expansion orders is demonstrated. Conclusions A method to calibrate wavefront aberrometry devices by using a standard sample of normal cases was devised. This method could be potentially useful in clinical studies involving patients with uncontrolled pupil sizes or in studies that compare data from aberrometers that use different Zernike fitting-order algorithms. PMID:22157570

Exploring Evidence Aggregation Methods and External Expansion Sources for Medical Record Search

DTIC Science & Technology

2012-11-01

Equation 3 using Indri in the same way as our previous work [12]. We denoted this model as MRM . A Combined Model We linearly combine MRF and MRM to get...retrieving indexing visits ranking III RbM VRM baseline/MRF/ MRM models ICD, NEG MbR Figure 1: Merging results from two different...retrieval model MRM with one expansion collection at a time to explore the expansion effectiveness of each collection as show in Table 5. As we can

Expansion of the invasive dwarf eelgrass, Zostera japonica, in Yaquina Bay, Oregon

EPA Science Inventory

The areal coverage of the non-indigenous dwarf eelgrass, Zostera japonica, is increasing in several estuaries on the US West Coast. As a result, regulatory agencies in the states of California and Washington are considering methods of controlling its expansion. Factors relevan...

A note on improved F-expansion method combined with Riccati equation applied to nonlinear evolution equations.

PubMed

Islam, Md Shafiqul; Khan, Kamruzzaman; Akbar, M Ali; Mastroberardino, Antonio

2014-10-01

The purpose of this article is to present an analytical method, namely the improved F-expansion method combined with the Riccati equation, for finding exact solutions of nonlinear evolution equations. The present method is capable of calculating all branches of solutions simultaneously, even if multiple solutions are very close and thus difficult to distinguish with numerical techniques. To verify the computational efficiency, we consider the modified Benjamin-Bona-Mahony equation and the modified Korteweg-de Vries equation. Our results reveal that the method is a very effective and straightforward way of formulating the exact travelling wave solutions of nonlinear wave equations arising in mathematical physics and engineering.

A note on improved F-expansion method combined with Riccati equation applied to nonlinear evolution equations

PubMed Central

Islam, Md. Shafiqul; Khan, Kamruzzaman; Akbar, M. Ali; Mastroberardino, Antonio

2014-01-01

The purpose of this article is to present an analytical method, namely the improved F-expansion method combined with the Riccati equation, for finding exact solutions of nonlinear evolution equations. The present method is capable of calculating all branches of solutions simultaneously, even if multiple solutions are very close and thus difficult to distinguish with numerical techniques. To verify the computational efficiency, we consider the modified Benjamin–Bona–Mahony equation and the modified Korteweg-de Vries equation. Our results reveal that the method is a very effective and straightforward way of formulating the exact travelling wave solutions of nonlinear wave equations arising in mathematical physics and engineering. PMID:26064530

Inversion of residual stress profiles from ultrasonic Rayleigh wave dispersion data

NASA Astrophysics Data System (ADS)

Mora, P.; Spies, M.

2018-05-01

We investigate theoretically and with synthetic data the performance of several inversion methods to infer a residual stress state from ultrasonic surface wave dispersion data. We show that this particular problem may reveal in relevant materials undesired behaviors for some methods that could be reliably applied to infer other properties. We focus on two methods, one based on a Taylor-expansion, and another one based on a piecewise linear expansion regularized by a singular value decomposition. We explain the instabilities of the Taylor-based method by highlighting singularities in the series of coefficients. At the same time, we show that the other method can successfully provide performances which only weakly depend on the material.

Structural reanalysis via a mixed method. [using Taylor series for accuracy improvement

NASA Technical Reports Server (NTRS)

Noor, A. K.; Lowder, H. E.

1975-01-01

A study is made of the approximate structural reanalysis technique based on the use of Taylor series expansion of response variables in terms of design variables in conjunction with the mixed method. In addition, comparisons are made with two reanalysis techniques based on the displacement method. These techniques are the Taylor series expansion and the modified reduced basis. It is shown that the use of the reciprocals of the sizing variables as design variables (which is the natural choice in the mixed method) can result in a substantial improvement in the accuracy of the reanalysis technique. Numerical results are presented for a space truss structure.

New extended (G'/G)-expansion method to solve nonlinear evolution equation: the (3 + 1)-dimensional potential-YTSF equation.

PubMed

Roshid, Harun-Or-; Akbar, M Ali; Alam, Md Nur; Hoque, Md Fazlul; Rahman, Nizhum

2014-01-01

In this article, a new extended (G'/G) -expansion method has been proposed for constructing more general exact traveling wave solutions of nonlinear evolution equations with the aid of symbolic computation. In order to illustrate the validity and effectiveness of the method, we pick the (3 + 1)-dimensional potential-YTSF equation. As a result, abundant new and more general exact solutions have been achieved of this equation. It has been shown that the proposed method provides a powerful mathematical tool for solving nonlinear wave equations in applied mathematics, engineering and mathematical physics.

Rapid iterative reanalysis for automated design

NASA Technical Reports Server (NTRS)

Bhatia, K. G.

1973-01-01

A method for iterative reanalysis in automated structural design is presented for a finite-element analysis using the direct stiffness approach. A basic feature of the method is that the generalized stiffness and inertia matrices are expressed as functions of structural design parameters, and these generalized matrices are expanded in Taylor series about the initial design. Only the linear terms are retained in the expansions. The method is approximate because it uses static condensation, modal reduction, and the linear Taylor series expansions. The exact linear representation of the expansions of the generalized matrices is also described and a basis for the present method is established. Results of applications of the present method to the recalculation of the natural frequencies of two simple platelike structural models are presented and compared with results obtained by using a commonly applied analysis procedure used as a reference. In general, the results are in good agreement. A comparison of the computer times required for the use of the present method and the reference method indicated that the present method required substantially less time for reanalysis. Although the results presented are for relatively small-order problems, the present method will become more efficient relative to the reference method as the problem size increases. An extension of the present method to static reanalysis is described, ana a basis for unifying the static and dynamic reanalysis procedures is presented.

Kalman filter parameter estimation for a nonlinear diffusion model of epithelial cell migration using stochastic collocation and the Karhunen-Loeve expansion.

PubMed

Barber, Jared; Tanase, Roxana; Yotov, Ivan

2016-06-01

Several Kalman filter algorithms are presented for data assimilation and parameter estimation for a nonlinear diffusion model of epithelial cell migration. These include the ensemble Kalman filter with Monte Carlo sampling and a stochastic collocation (SC) Kalman filter with structured sampling. Further, two types of noise are considered -uncorrelated noise resulting in one stochastic dimension for each element of the spatial grid and correlated noise parameterized by the Karhunen-Loeve (KL) expansion resulting in one stochastic dimension for each KL term. The efficiency and accuracy of the four methods are investigated for two cases with synthetic data with and without noise, as well as data from a laboratory experiment. While it is observed that all algorithms perform reasonably well in matching the target solution and estimating the diffusion coefficient and the growth rate, it is illustrated that the algorithms that employ SC and KL expansion are computationally more efficient, as they require fewer ensemble members for comparable accuracy. In the case of SC methods, this is due to improved approximation in stochastic space compared to Monte Carlo sampling. In the case of KL methods, the parameterization of the noise results in a stochastic space of smaller dimension. The most efficient method is the one combining SC and KL expansion. Copyright © 2016 Elsevier Inc. All rights reserved.

Construction of ground-state preserving sparse lattice models for predictive materials simulations

NASA Astrophysics Data System (ADS)

Huang, Wenxuan; Urban, Alexander; Rong, Ziqin; Ding, Zhiwei; Luo, Chuan; Ceder, Gerbrand

2017-08-01

First-principles based cluster expansion models are the dominant approach in ab initio thermodynamics of crystalline mixtures enabling the prediction of phase diagrams and novel ground states. However, despite recent advances, the construction of accurate models still requires a careful and time-consuming manual parameter tuning process for ground-state preservation, since this property is not guaranteed by default. In this paper, we present a systematic and mathematically sound method to obtain cluster expansion models that are guaranteed to preserve the ground states of their reference data. The method builds on the recently introduced compressive sensing paradigm for cluster expansion and employs quadratic programming to impose constraints on the model parameters. The robustness of our methodology is illustrated for two lithium transition metal oxides with relevance for Li-ion battery cathodes, i.e., Li2xFe2(1-x)O2 and Li2xTi2(1-x)O2, for which the construction of cluster expansion models with compressive sensing alone has proven to be challenging. We demonstrate that our method not only guarantees ground-state preservation on the set of reference structures used for the model construction, but also show that out-of-sample ground-state preservation up to relatively large supercell size is achievable through a rapidly converging iterative refinement. This method provides a general tool for building robust, compressed and constrained physical models with predictive power.

Iterative expansion microscopy.

PubMed

Chang, Jae-Byum; Chen, Fei; Yoon, Young-Gyu; Jung, Erica E; Babcock, Hazen; Kang, Jeong Seuk; Asano, Shoh; Suk, Ho-Jun; Pak, Nikita; Tillberg, Paul W; Wassie, Asmamaw T; Cai, Dawen; Boyden, Edward S

2017-06-01

We recently developed a method called expansion microscopy, in which preserved biological specimens are physically magnified by embedding them in a densely crosslinked polyelectrolyte gel, anchoring key labels or biomolecules to the gel, mechanically homogenizing the specimen, and then swelling the gel-specimen composite by ∼4.5× in linear dimension. Here we describe iterative expansion microscopy (iExM), in which a sample is expanded ∼20×. After preliminary expansion a second swellable polymer mesh is formed in the space newly opened up by the first expansion, and the sample is expanded again. iExM expands biological specimens ∼4.5 × 4.5, or ∼20×, and enables ∼25-nm-resolution imaging of cells and tissues on conventional microscopes. We used iExM to visualize synaptic proteins, as well as the detailed architecture of dendritic spines, in mouse brain circuitry.

The ideas behind self-consistent expansion

NASA Astrophysics Data System (ADS)

Schwartz, Moshe; Katzav, Eytan

2008-04-01

In recent years we have witnessed a growing interest in various non-equilibrium systems described in terms of stochastic nonlinear field theories. In some of those systems, like KPZ and related models, the interesting behavior is in the strong coupling regime, which is inaccessible by traditional perturbative treatments such as dynamical renormalization group (DRG). A useful tool in the study of such systems is the self-consistent expansion (SCE), which might be said to generate its own 'small parameter'. The self-consistent expansion (SCE) has the advantage that its structure is just that of a regular expansion, the only difference is that the simple system around which the expansion is performed is adjustable. The purpose of this paper is to present the method in a simple and understandable way that hopefully will make it accessible to a wider public working on non-equilibrium statistical physics.

Pseudonegative thermal expansion and the state of water in graphene oxide layered assemblies.

PubMed

Zhu, Jian; Andres, Christine M; Xu, Jiadi; Ramamoorthy, Ayyalusamy; Tsotsis, Thomas; Kotov, Nicholas A

2012-09-25

Unraveling the complex interplay between thermal properties and hydration is a part of understanding the fundamental properties of many soft materials and very essential for many applications. Here we show that graphene oxide (GO) demonstrates a highly negative thermal expansion (NTE) coefficient owing to unique thermohydration processes related with fast transport of water between the GO sheets, the amphiphilic nature of nanochannels, and close-to-zero intrinsic thermal expansion of GO. The humidity-dependent NTE of GO layered assemblies, or "pseudonegative thermal expansion" (PNTE), differs from that of other hygroscopic materials due to its relatively fast and highly reversible expansion/contraction cycles and occurrence at low humidity levels while bearing similarities to classic NTE. Thermal expansion of polyvinyl alcohol/GO composites is easily tunable with additional intricacy of thermohydration effects. PNTE combined with isotropy, nontoxicity, and mechanical robustness is an asset for applications of actuators, sensors, MEMS devices, and memory materials and crucial for developing methods of thermal/photopatterning of GO devices.

Inhibitory Effect of Waste Glass Powder on ASR Expansion Induced by Waste Glass Aggregate

PubMed Central

Liu, Shuhua; Wang, Shu; Tang, Wan; Hu, Ningning; Wei, Jianpeng

2015-01-01

Detailed research is carried out to ascertain the inhibitory effect of waste glass powder (WGP) on alkali-silica reaction (ASR) expansion induced by waste glass aggregate in this paper. The alkali reactivity of waste glass aggregate is examined by two methods in accordance with the China Test Code SL352-2006. The potential of WGP to control the ASR expansion is determined in terms of mean diameter, specific surface area, content of WGP and curing temperature. Two mathematical models are developed to estimate the inhibitory efficiency of WGP. These studies show that there is ASR risk with an ASR expansion rate over 0.2% when the sand contains more than 30% glass aggregate. However, WGP can effectively control the ASR expansion and inhibit the expansion rate induced by the glass aggregate to be under 0.1%. The two mathematical models have good simulation results, which can be used to evaluate the inhibitory effect of WGP on ASR risk. PMID:28793603

Finite element analysis of residual stress in cold expanded plate with different thickness and expansion ratio

NASA Astrophysics Data System (ADS)

Arifin Shariffudin, Kamarul; Karuppanan, Saravanan; Patil, Santosh S.

2017-10-01

Cold expansion of fastener/rivet holes is a common way to generate beneficial compressive residual stress around the fastener hole. In this study, cold expansion process was simulated by finite-element method in order to determine the residual stress field around two cold expanded holes by varying the plate thickness and expansion ratio of the hole. The model was developed in ANSYS and assigned to aluminium alloy 7475-T61 material model. The results showed that the residual stress become more compressive as the plate thickness is increased up to t/d = 2.6 and decreased for further level of thickness. In addition, the residual stress at the edge of the hole become more compressive as the expansion ratio is increased up to 4.5% and decreased for further level of expansion. This study also found that the residual stresses near the entrance and the exit face of the plate are less compressive than the residual stresses on the mid-thickness of the plate.

Co-optimizing Generation and Transmission Expansion with Wind Power in Large-Scale Power Grids Implementation in the US Eastern Interconnection

DOE PAGES

You, Shutang; Hadley, Stanton W.; Shankar, Mallikarjun; ...

2016-01-12

This paper studies the generation and transmission expansion co-optimization problem with a high wind power penetration rate in the US Eastern Interconnection (EI) power grid. In this paper, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. Our paper also analyzed a time series generation method to capture the variation and correlation of both load and wind power across regions. The obtained series can be easily introduced into the expansion planning problem and then solved through existing MIP solvers. Simulation results show that the proposed planning model and series generation methodmore » can improve the expansion result significantly through modeling more detailed information of wind and load variation among regions in the US EI system. Moreover, the improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare in large-scale power grids.« less

Exact Solutions of Atmospheric (2+1)-Dimensional Nonlinear Incompressible Non-hydrostatic Boussinesq Equations

NASA Astrophysics Data System (ADS)

Liu, Ping; Wang, Ya-Xiong; Ren, Bo; Li, Jin-Hua

2016-12-01

Exact solutions of the atmospheric (2+1)-dimensional nonlinear incompressible non-hydrostatic Boussinesq (INHB) equations are researched by Combining function expansion and symmetry method. By function expansion, several expansion coefficient equations are derived. Symmetries and similarity solutions are researched in order to obtain exact solutions of the INHB equations. Three types of symmetry reduction equations and similarity solutions for the expansion coefficient equations are proposed. Non-traveling wave solutions for the INHB equations are obtained by symmetries of the expansion coefficient equations. Making traveling wave transformations on expansion coefficient equations, we demonstrate some traveling wave solutions of the INHB equations. The evolutions on the wind velocities, temperature perturbation and pressure perturbation are demonstrated by figures, which demonstrate the periodic evolutions with time and space. Supported by the National Natural Science Foundation of China under Grant Nos. 11305031 and 11305106, and Training Programme Foundation for Outstanding Young Teachers in Higher Education Institutions of Guangdong Province under Grant No. Yq2013205

Thermal expansion of coexistence of ferromagnetism and superconductivity

NASA Astrophysics Data System (ADS)

Hatayama, Nobukuni; Konno, Rikio

2010-01-01

The temperature dependence of thermal expansion of coexistence of ferromag-netism and superconductivity below the superconducting transition temperature Tc↑ of a majority spin conduction band is investigated. Majority spin and minority spin superconducting gaps exist in the coexistent state. We assume that the Curie temperature is much larger than the superconducting transition temperatures. The free energy that Linder et al. [Phys. Rev. B76, 054511 (2007)] derived is used. The thermal expansion of coexistence of ferromagnetism and superconductivity is derived by the application of the method of Takahashi and Nakano [J. Phys.: Condens. Matter 18, 521 (2006)]. We find that we have the anomalies of the thermal expansion in the vicinity of the superconducting transition temperatures.

The thermal expansion of hard magnetic materials of the Nd-Fe-B system

NASA Astrophysics Data System (ADS)

Savchenko, Igor; Kozlovskii, Yurii; Samoshkin, Dmitriy; Yatsuk, Oleg

2017-10-01

The results of dilatometric measurement of the thermal expansion of hard magnetic materials brands N35M, N35H and N35SH containing as a main component the crystalline phase of Nd2Fe14B type are presented. The temperature range from 200 to 750 K has been investigated by the method of dilatometry with an error of 1.5-2×10-7 K-1. The approximation dependences of the linear thermal expansion coefficient have been obtained. The character of changes of the thermal coefficient of linear expansion in the region of the Curie point has been specified, its critical indices and critical amplitudes have been defined.

Thermal expansion of quaternary nitride coatings

NASA Astrophysics Data System (ADS)

Tasnádi, Ferenc; Wang, Fei; Odén, Magnus; Abrikosov, Igor A.

2018-04-01

The thermal expansion coefficient of technologically relevant multicomponent cubic nitride alloys are predicted using the Debye model with ab initio elastic constants calculated at 0 K and an isotropic approximation for the Grüneisen parameter. Our method is benchmarked against measured thermal expansion of TiN and Ti(1-x)Al x N as well as against results of molecular dynamics simulations. We show that the thermal expansion coefficients of Ti(1-x-y)X y Al x N (X  =  Zr, Hf, Nb, V, Ta) solid solutions monotonously increase with the amount of alloying element X at all temperatures except for Zr and Hf, for which they instead decrease for y≳ 0.5 .

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

40 CFR 63.323 - Test methods and monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... downstream from any flow disturbance such as a bend, expansion, contraction, or outlet; downstream from no other inlet; and 2 stack or duct diameters upstream from any flow disturbance such as a bend, expansion... monitoring by inserting the colorimetric detector or PCE gas analyzer tube into the open space above the...

Expansive Visibilization to Stimulate EFL Teacher Reflection

ERIC Educational Resources Information Center

Ito, Ryu

2012-01-01

Despite the growing popularity of action research, bridging the gap between data collection and reflective data analysis still lacks a well-developed methodology. As a supplement to the traditional action research procedure for language teaching, I adopted a method called expansive visibilization (EV), which has the potential to be a reflective…

Polynomial Chaos Based Acoustic Uncertainty Predictions from Ocean Forecast Ensembles

NASA Astrophysics Data System (ADS)

Dennis, S.

2016-02-01

Most significant ocean acoustic propagation occurs at tens of kilometers, at scales small compared basin and to most fine scale ocean modeling. To address the increased emphasis on uncertainty quantification, for example transmission loss (TL) probability density functions (PDF) within some radius, a polynomial chaos (PC) based method is utilized. In order to capture uncertainty in ocean modeling, Navy Coastal Ocean Model (NCOM) now includes ensembles distributed to reflect the ocean analysis statistics. Since the ensembles are included in the data assimilation for the new forecast ensembles, the acoustic modeling uses the ensemble predictions in a similar fashion for creating sound speed distribution over an acoustically relevant domain. Within an acoustic domain, singular value decomposition over the combined time-space structure of the sound speeds can be used to create Karhunen-Loève expansions of sound speed, subject to multivariate normality testing. These sound speed expansions serve as a basis for Hermite polynomial chaos expansions of derived quantities, in particular TL. The PC expansion coefficients result from so-called non-intrusive methods, involving evaluation of TL at multi-dimensional Gauss-Hermite quadrature collocation points. Traditional TL calculation from standard acoustic propagation modeling could be prohibitively time consuming at all multi-dimensional collocation points. This method employs Smolyak order and gridding methods to allow adaptive sub-sampling of the collocation points to determine only the most significant PC expansion coefficients to within a preset tolerance. Practically, the Smolyak order and grid sizes grow only polynomially in the number of Karhunen-Loève terms, alleviating the curse of dimensionality. The resulting TL PC coefficients allow the determination of TL PDF normality and its mean and standard deviation. In the non-normal case, PC Monte Carlo methods are used to rapidly establish the PDF. This work was sponsored by the Office of Naval Research

Psychometric evaluation of the Persian version of the quality of life in epilepsy inventory-31

PubMed Central

Mohammadi, Navid; Kian, Shiva; Nia, Seyed Mohammad Ali Akbarian; Nojomi, Marzieh

2013-01-01

Background Health assessment in patients with epilepsy (PWE) should include both clinical outcomes and health related quality of life (HRQOL) measures. The quality of life (QoL) in epilepsy-31 inventory (QOLIE-31) is widely used for QOL studies in epilepsy. This study aims to evaluate psychometrics of the Persian version of the inventory (QOLIE-31-P). Methods Following a standard forward-backward translation and cultural adaptation, the construct validity of the QOLIE-31-P was assessed by explanatory factor analysis, multi-trait scaling analysis, and known group comparison. The criterion validity was assessed by calculating the Pearson correlation to SF-36 (36-item short-form health survey). The reliability was assessed by calculating Cronbach's alpha and test-retest study. Results The factor analysis extracted from 8 factors explaining 70.35% of the variations. Item-scale correlations revealed that individual items significantly had the strongest association with the domain they were loaded on. The Pearson coefficient of correlation between QOLIE-31-P and the overall scores of SF-36 was 0.876 (P < 0.0001). Patient with medically controlled seizures scored higher than those who experienced seizures during the previous year to study date (P < 0.0001). The Cronbach's α of overall QOLIE-31-P inventory was 0.9. The overall test-retest coefficient of correlation was 0.68 (P = 0.003). Conclusion QOLIE-31-P is a valid and reliable tool to be applied in health assessment of patients with epilepsy. PMID:24250924

Clinical experience with generic levetiracetam in people with epilepsy

PubMed Central

Chaluvadi, Siresha; Chiang, Sharon; Tran, Larry; Goldsmith, Corey E.; Friedman, David E.

2015-01-01

SUMMARY Purpose To describe the clinical outcomes of a compulsory switch from branded to generic levetiracetam (LEV) among people with epilepsy (PWE) in an outpatient setting. Methods We conducted a retrospective chart review of 760 unduplicated consecutive adult patients attending a tertiary care epilepsy clinic at Ben Taub General Hospital. On November 1, 2008 hospital policy required all patients receiving branded LEV to be automatically switched to generic LEV. We calculated the proportion of patients switching back to branded LEV and reasons for the switch back. Key Findings Of the 260 patients (34%) being prescribed LEV (generic and brand name) during the study period, 105 (42.9%) were switched back to brand name LEV by their treating physicians. Reasons for switch back included increase in seizure frequency (19.6% vs. 1.6%; p < 0.0001) and adverse effects (AEs) (3.3%). AEs included headache, fatigue, and aggression. Patient age was associated with switchback when controlling for gender, epilepsy classification, and treatment characteristics [relative risk (RR) 2.44; 95% confidence interval (CI) 2.09–2.84; p < 0.05)]. An increase in seizure frequency subsequent to generic substitution was associated with polytherapy compared to monotherapy (3.225; 1.512–6.880; p < 0.05). Significance A significant proportion of patients in our cohort on generic LEV required switch back to the branded drug. Careful monitoring is imperative because a compulsory switch from branded to generic LEV may lead to poor clinical outcomes, with risk of AEs and increased seizure frequency. PMID:21426334

Coupling-parameter expansion in thermodynamic perturbation theory.

PubMed

Ramana, A Sai Venkata; Menon, S V G

2013-02-01

An approach to the coupling-parameter expansion in the liquid state theory of simple fluids is presented by combining the ideas of thermodynamic perturbation theory and integral equation theories. This hybrid scheme avoids the problems of the latter in the two phase region. A method to compute the perturbation series to any arbitrary order is developed and applied to square well fluids. Apart from the Helmholtz free energy, the method also gives the radial distribution function and the direct correlation function of the perturbed system. The theory is applied for square well fluids of variable ranges and compared with simulation data. While the convergence of perturbation series and the overall performance of the theory is good, improvements are needed for potentials with shorter ranges. Possible directions for further developments in the coupling-parameter expansion are indicated.

A fixed mass method for the Kramers-Moyal expansion--application to time series with outliers.

PubMed

Petelczyc, M; Żebrowski, J J; Orłowska-Baranowska, E

2015-03-01

Extraction of stochastic and deterministic components from empirical data-necessary for the reconstruction of the dynamics of the system-is discussed. We determine both components using the Kramers-Moyal expansion. In our earlier papers, we obtained large fluctuations in the magnitude of both terms for rare or extreme valued events in the data. Calculations for such events are burdened by an unsatisfactory quality of the statistics. In general, the method is sensitive to the binning procedure applied for the construction of histograms. Instead of the commonly used constant width of bins, we use here a constant number of counts for each bin. This approach-the fixed mass method-allows to include in the calculation events, which do not yield satisfactory statistics in the fixed bin width method. The method developed is general. To demonstrate its properties, here, we present the modified Kramers-Moyal expansion method and discuss its properties by the application of the fixed mass method to four representative heart rate variability recordings with different numbers of ectopic beats. These beats may be rare events as well as outlying, i.e., very small or very large heart cycle lengths. The properties of ectopic beats are important not only for medical diagnostic purposes but the occurrence of ectopic beats is a general example of the kind of variability that occurs in a signal with outliers. To show that the method is general, we also present results for two examples of data from very different areas of science: daily temperatures at a large European city and recordings of traffics on a highway. Using the fixed mass method, to assess the dynamics leading to the outlying events we studied the occurrence of higher order terms of the Kramers-Moyal expansion in the recordings. We found that the higher order terms of the Kramers-Moyal expansion are negligible for heart rate variability. This finding opens the possibility of the application of the Langevin equation to the whole range of empirical signals containing rare or outlying events. Note, however, that the higher order terms are non-negligible for the other data studied here and for it the Langevin equation is not applicable as a model.

Carbon Dioxide-Based versus Saline Tissue Expansion for Breast Reconstruction: Results of the XPAND Prospective, Randomized Clinical Trial.

PubMed

Ascherman, Jeffrey A; Zeidler, Kamakshi; Morrison, Kerry A; Appel, James Z; Berkowitz, R L; Castle, John; Colwell, Amy; Chun, Yoon; Johnson, Debra; Mohebali, Khashayar

2016-12-01

AeroForm is a new type of remote-controlled, needle-free, carbon dioxide-based expander involving a potentially faster method of tissue expansion. Results are presented here from the AirXpanders Patient Activated Controlled Tissue Expander pivotal trial comparing AeroForm to saline tissue expanders. Women undergoing two-stage breast reconstruction were randomized at 17 U.S. sites in this U.S. Food and Drug Administration-approved investigational device exemption trial. Expansion in the investigational arm was performed by the patient in 10-cc increments up to 30 cc/day of carbon dioxide and in the control arm by the physician with periodic bolus injections of saline. Safety endpoints, expansion and reconstruction times, pain, and satisfaction were assessed. One hundred fifty women were treated: 98 with carbon dioxide expanders (n = 168) and 52 with saline expanders (n = 88). The treatment success rate (all breasts exchanged successfully excluding non-device-related failures) was 96.1 percent for carbon dioxide and 98.8 percent for saline. Median time to full expansion and completion of the second-stage operation was 21.0 and 108.5 days (carbon dioxide) versus 46.0 and 136.5 days (saline), respectively, with a similar rate of overall complications. Ease of use for the carbon dioxide expander was rated high by patients (98 percent) and physicians (90 percent). The AirXpanders Patient Activated Controlled Tissue Expander trial results demonstrate that a carbon dioxide-based expander is an effective method of tissue expansion with a similar overall adverse event rate compared to saline expanders, and provides a more convenient and expedient expansion. Therapeutic, I.

Glacial Lake Expansion in the Central Himalayas by Landsat Images, 1990–2010

PubMed Central

Nie, Yong; Liu, Qiao; Liu, Shiyin

2013-01-01

Glacial lake outburst flood (GLOF) is a serious hazard in high, mountainous regions. In the Himalayas, catastrophic risks of GLOFs have increased in recent years because most Himalayan glaciers have experienced remarkable downwasting under a warming climate. However, current knowledge about the distribution and recent changes in glacial lakes within the central Himalaya mountain range is still limited. Here, we conducted a systematic investigation of the glacial lakes within the entire central Himalaya range by using an object-oriented image processing method based on the Landsat Thematic Mapper (TM) or Enhanced Thematic Mapper (ETM) images from 1990 to 2010. We extracted the lake boundaries for four time points (1990, 2000, 2005 and 2010) and used a time series inspection method combined with a consistent spatial resolution of Landsat images that consistently revealed lake expansion. Our results show that the glacial lakes expanded rapidly by 17.11% from 1990 to 2010. The pre-existing, larger glacial lakes, rather than the newly formed lakes, contributed most to the areal expansion. The greatest expansions occurred at the altitudinal zones between 4800 m and 5600 m at the north side of the main Himalayan range and between 4500 m and 5600 m at the south side, respectively. Based on the expansion rate, area and type of glacial lakes, we identified 67 rapidly expanding glacial lakes in the central Himalayan region that need to be closely monitored in the future. The warming and increasing amounts of light-absorbing constituents of snow and ice could have accelerated the melting that directly affected the glacial lake expansion. Across the main central Himalayas, glacial lakes at the north side show more remarkable expansion than those at the south side. An effective monitoring and warning system for critical glacial lakes is urgently needed. PMID:24376778

Glacial lake expansion in the central Himalayas by Landsat images, 1990-2010.

PubMed

Nie, Yong; Liu, Qiao; Liu, Shiyin

2013-01-01

Glacial lake outburst flood (GLOF) is a serious hazard in high, mountainous regions. In the Himalayas, catastrophic risks of GLOFs have increased in recent years because most Himalayan glaciers have experienced remarkable downwasting under a warming climate. However, current knowledge about the distribution and recent changes in glacial lakes within the central Himalaya mountain range is still limited. Here, we conducted a systematic investigation of the glacial lakes within the entire central Himalaya range by using an object-oriented image processing method based on the Landsat Thematic Mapper (TM) or Enhanced Thematic Mapper (ETM) images from 1990 to 2010. We extracted the lake boundaries for four time points (1990, 2000, 2005 and 2010) and used a time series inspection method combined with a consistent spatial resolution of Landsat images that consistently revealed lake expansion. Our results show that the glacial lakes expanded rapidly by 17.11% from 1990 to 2010. The pre-existing, larger glacial lakes, rather than the newly formed lakes, contributed most to the areal expansion. The greatest expansions occurred at the altitudinal zones between 4800 m and 5600 m at the north side of the main Himalayan range and between 4500 m and 5600 m at the south side, respectively. Based on the expansion rate, area and type of glacial lakes, we identified 67 rapidly expanding glacial lakes in the central Himalayan region that need to be closely monitored in the future. The warming and increasing amounts of light-absorbing constituents of snow and ice could have accelerated the melting that directly affected the glacial lake expansion. Across the main central Himalayas, glacial lakes at the north side show more remarkable expansion than those at the south side. An effective monitoring and warning system for critical glacial lakes is urgently needed.

Glacial Lake Expansion in the Central Himalayas By Landsat Images, 1990-2010

NASA Astrophysics Data System (ADS)

Nie, Y.; Liu, Q.; Liu, S.

2014-12-01

Glacial lake outburst flood (GLOF) is a serious hazard in high, mountainous regions. In the Himalayas, catastrophic risks of GLOFs have increased in recent years because most Himalayan glaciers have experienced remarkable downwasting under a warming climate. However, current knowledge about the distribution and recent changes in glacial lakes within the central Himalaya mountain range is still limited. Here, we conducted a systematic investigation of the glacial lakes within the entire central Himalaya range by using an object-oriented image processing method based on the Landsat Thematic Mapper (TM) or Enhanced Thematic Mapper (ETM) images from 1990 to 2010. We extracted the lake boundaries for four time points (1990, 2000, 2005 and 2010) and used a time series inspection method combined with a consistent spatial resolution of Landsat images that consistently revealed lake expansion. Our results show that the glacial lakes expanded rapidly by 17.11% from 1990 to 2010. The pre-existing, larger glacial lakes, rather than the newly formed lakes, contributed most to the areal expansion. The greatest expansions occurred at the altitudinal zones between 4800 m and 5600 m at the north side of the main Himalayan range and between 4500 m and 5600 m at the south side, respectively. Based on the expansion rate, area and type of glacial lakes, we identified 67 rapidly expanding glacial lakes in the central Himalayan region that need to be closely monitored in the future. The warming and increasing amounts of light-absorbing constituents of snow and ice could have accelerated the melting that directly affected the glacial lake expansion. Across the main central Himalayas, glacial lakes at the north side show more remarkable expansion than those at the south side. An effective monitoring and warning system for critical glacial lakes is urgently needed.

A machine learning approach to graph-theoretical cluster expansions of the energy of adsorbate layers

NASA Astrophysics Data System (ADS)

Vignola, Emanuele; Steinmann, Stephan N.; Vandegehuchte, Bart D.; Curulla, Daniel; Stamatakis, Michail; Sautet, Philippe

2017-08-01

The accurate description of the energy of adsorbate layers is crucial for the understanding of chemistry at interfaces. For heterogeneous catalysis, not only the interaction of the adsorbate with the surface but also the adsorbate-adsorbate lateral interactions significantly affect the activation energies of reactions. Modeling the interactions of the adsorbates with the catalyst surface and with each other can be efficiently achieved in the cluster expansion Hamiltonian formalism, which has recently been implemented in a graph-theoretical kinetic Monte Carlo (kMC) scheme to describe multi-dentate species. Automating the development of the cluster expansion Hamiltonians for catalytic systems is challenging and requires the mapping of adsorbate configurations for extended adsorbates onto a graphical lattice. The current work adopts machine learning methods to reach this goal. Clusters are automatically detected based on formalized, but intuitive chemical concepts. The corresponding energy coefficients for the cluster expansion are calculated by an inversion scheme. The potential of this method is demonstrated for the example of ethylene adsorption on Pd(111), for which we propose several expansions, depending on the graphical lattice. It turns out that for this system, the best description is obtained as a combination of single molecule patterns and a few coupling terms accounting for lateral interactions.

Solitons of the Kadomtsev-Petviashvili equation based on lattice Boltzmann model

NASA Astrophysics Data System (ADS)

Wang, Huimin

2017-01-01

In this paper, a lattice Boltzmann model for the Kadomtsev-Petviashvili equation is proposed. By using the Chapman-Enskog expansion and the multi-scale time expansion, a series of partial differential equations in different time scales are obtained. Due to the asymmetry in x direction and y direction of the equation, the moments of the equilibrium distribution function are selected are asymmetric. The numerical results demonstrate the lattice Boltzmann method is an effective method to simulate the solitons of the Kadomtsev-Petviashvili equation.

Exact soliton of (2 + 1)-dimensional fractional Schrödinger equation

NASA Astrophysics Data System (ADS)

Rizvi, S. T. R.; Ali, K.; Bashir, S.; Younis, M.; Ashraf, R.; Ahmad, M. O.

2017-07-01

The nonlinear fractional Schrödinger equation is the basic equation of fractional quantum mechanics introduced by Nick Laskin in 2002. We apply three tools to solve this mathematical-physical model. First, we find the solitary wave solutions including the trigonometric traveling wave solutions, bell and kink shape solitons using the F-expansion and Improve F-expansion method. We also obtain the soliton solution, singular soliton solutions, rational function solution and elliptic integral function solutions, with the help of the extended trial equation method.

Resonant-state expansion for open optical systems: generalization to magnetic, chiral, and bi-anisotropic materials

NASA Astrophysics Data System (ADS)

Muljarov, E. A.; Weiss, T.

2018-05-01

The resonant-state expansion, a recently developed powerful method in electrodynamics, is generalized here for open optical systems containing magnetic, chiral, or bi-anisotropic materials. It is shown that the key matrix eigenvalue equation of the method remains the same, but the matrix elements of the perturbation now contain variations of the permittivity, permeability, and bi-anisotropy tensors. A general normalization of resonant states in terms of the electric and magnetic fields is presented.

Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport.

PubMed

Xie, Hang; Kwok, Yanho; Jiang, Feng; Zheng, Xiao; Chen, GuanHua

2014-10-28

Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.

Large-scale expansion of γδ T cells and peptide-specific cytotoxic T cells using zoledronate for adoptive immunotherapy.

PubMed

Yoshikawa, Toshiaki; Takahara, Masashi; Tomiyama, Mai; Nieda, Mie; Maekawa, Ryuji; Nakatsura, Tetsuya

2014-11-01

Specific cellular immunotherapy for cancer requires efficient generation and expansion of cytotoxic T lymphocytes (CTLs) that recognize tumor-associated antigens. However, it is difficult to isolate and expand functionally active T-cells ex vivo. In this study, we investigated the efficacy of a new method to induce expansion of antigen-specific CTLs for adoptive immunotherapy. We used tumor-associated antigen glypican-3 (GPC3)-derived peptide and cytomegalovirus (CMV)-derived peptide as antigens. Treatment of human peripheral blood mononuclear cells (PBMCs) with zoledronate is a method that enables large-scale γδ T-cell expansion. To induce expansion of γδ T cells and antigen-specific CTLs, the PBMCs of healthy volunteers or patients vaccinated with GPC3 peptide were cultured with both peptide and zoledronate for 14 days. The expansion of γδ T cells and peptide-specific CTLs from a few PBMCs using zoledronate yields cell numbers sufficient for adoptive transfer. The rate of increase of GPC3‑specific CTLs was approximately 24- to 170,000-fold. These CD8(+) cells, including CTLs, showed GPC3-specific cytotoxicity against SK-Hep-1/hGPC3 and T2 pulsed with GPC3 peptide, but not against SK-Hep-1/vec and T2 pulsed with human immunodeficiency virus peptide. On the other hand, CD8(-) cells, including γδ T cells, showed cytotoxicity against SK-Hep-1/hGPC3 and SK-Hep-1/vec, but did not show GPC3 specificity. Furthermore, adoptive cell transfer of CD8(+) cells, CD8(-) cells, and total cells after expansion significantly inhibited tumor growth in an NOD/SCID mouse model. This study indicates that simultaneous expansion of γδ T cells and peptide-specific CTLs using zoledronate is useful for adoptive immunotherapy.

Crossing statistic: reconstructing the expansion history of the universe

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

Shafieloo, Arman, E-mail: arman@ewha.ac.kr

2012-08-01

We present that by combining Crossing Statistic [1,2] and Smoothing method [3-5] one can reconstruct the expansion history of the universe with a very high precision without considering any prior on the cosmological quantities such as the equation of state of dark energy. We show that the presented method performs very well in reconstruction of the expansion history of the universe independent of the underlying models and it works well even for non-trivial dark energy models with fast or slow changes in the equation of state of dark energy. Accuracy of the reconstructed quantities along with independence of the methodmore » to any prior or assumption gives the proposed method advantages to the other non-parametric methods proposed before in the literature. Applying on the Union 2.1 supernovae combined with WiggleZ BAO data we present the reconstructed results and test the consistency of the two data sets in a model independent manner. Results show that latest available supernovae and BAO data are in good agreement with each other and spatially flat ΛCDM model is in concordance with the current data.« less

Toward unbiased estimations of the statefinder parameters

NASA Astrophysics Data System (ADS)

Aviles, Alejandro; Klapp, Jaime; Luongo, Orlando

2017-09-01

With the use of simulated supernova catalogs, we show that the statefinder parameters turn out to be poorly and biased estimated by standard cosmography. To this end, we compute their standard deviations and several bias statistics on cosmologies near the concordance model, demonstrating that these are very large, making standard cosmography unsuitable for future and wider compilations of data. To overcome this issue, we propose a new method that consists in introducing the series of the Hubble function into the luminosity distance, instead of considering the usual direct Taylor expansions of the luminosity distance. Moreover, in order to speed up the numerical computations, we estimate the coefficients of our expansions in a hierarchical manner, in which the order of the expansion depends on the redshift of every single piece of data. In addition, we propose two hybrids methods that incorporates standard cosmography at low redshifts. The methods presented here perform better than the standard approach of cosmography both in the errors and bias of the estimated statefinders. We further propose a one-parameter diagnostic to reject non-viable methods in cosmography.

Light-cone expansion of the Dirac sea in the presence of chiral and scalar potentials

NASA Astrophysics Data System (ADS)

Finster, Felix

2000-10-01

We study the Dirac sea in the presence of external chiral and scalar/pseudoscalar potentials. In preparation, a method is developed for calculating the advanced and retarded Green's functions in an expansion around the light cone. For this, we first expand all Feynman diagrams and then explicitly sum up the perturbation series. The light-cone expansion expresses the Green's functions as an infinite sum of line integrals over the external potential and its partial derivatives. The Dirac sea is decomposed into a causal and a noncausal contribution. The causal contribution has a light-cone expansion which is closely related to the light-cone expansion of the Green's functions; it describes the singular behavior of the Dirac sea in terms of nested line integrals along the light cone. The noncausal contribution, on the other hand, is, to every order in perturbation theory, a smooth function in position space.

Reducing vibration transfer from power plants by active methods

NASA Astrophysics Data System (ADS)

Kiryukhin, A. V.; Milman, O. O.; Ptakhin, A. V.

2017-12-01

The possibility of applying the methods of active damping of vibration and pressure pulsations for reducing their transfer from power plants into the environment, the seating, and the industrial premises are considered. The results of experimental works implemented by the authors on the active broadband damping of vibration and dynamic forces after shock-absorption up to 15 dB in the frequency band up to 150 Hz, of water pressure pulsations in the pipeline up to 20 dB in the frequency band up to 600 Hz, and of spatial low-frequency air noise indoors of a diesel generator at discrete frequency up to 20 dB are presented. It is shown that a reduction of vibration transfer through a vibration-isolating junction (expansion joints) of pipelines with liquid is the most complicated and has hardly been developed so far. This problem is essential for vibration isolation of power equipment from the seating and the environment through pipelines with water and steam in the power and transport engineering, shipbuilding, and in oil and gas pipelines in pumping stations. For improving efficiency, reducing the energy consumption, and decreasing the overall dimensions of equipment, it is advisable to combine the work of an active system with passive damping means, the use of which is not always sufficient. The executive component of the systems of active damping should be placed behind the vibration isolators (expansion joints). It is shown that the existence of working medium and connection of vibration with pressure pulsations in existing designs of pipeline expansion joints lead to growth of vibration stiffness of the expansion joint with the environment by two and more orders as compared with the static stiffness and makes difficulties for using the active methods. For active damping of vibration transfer through expansion joints of pipelines with a liquid, it is necessary to develop expansion joint structures with minimal connection of vibrations and pulsations and minimal vibration stiffness in the specified frequency range. The example of structure of such expansion joint and its test results are presented.

Molecular wave function and effective adiabatic potentials calculated by extended multi-configuration time-dependent Hartree-Fock method

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

Kato, Tsuyoshi; Ide, Yoshihiro; Yamanouchi, Kaoru

We first calculate the ground-state molecular wave function of 1D model H{sub 2} molecule by solving the coupled equations of motion formulated in the extended multi-configuration time-dependent Hartree-Fock (MCTDHF) method by the imaginary time propagation. From the comparisons with the results obtained by the Born-Huang (BH) expansion method as well as with the exact wave function, we observe that the memory size required in the extended MCTDHF method is about two orders of magnitude smaller than in the BH expansion method to achieve the same accuracy for the total energy. Second, in order to provide a theoretical means to understandmore » dynamical behavior of the wave function, we propose to define effective adiabatic potential functions and compare them with the conventional adiabatic electronic potentials, although the notion of the adiabatic potentials is not used in the extended MCTDHF approach. From the comparison, we conclude that by calculating the effective potentials we may be able to predict the energy differences among electronic states even for a time-dependent system, e.g., time-dependent excitation energies, which would be difficult to be estimated within the BH expansion approach.« less

Large-scale ex vivo expansion and characterization of natural killer cells for clinical applications

PubMed Central

LAPTEVA, NATALIA; DURETT, APRIL G.; SUN, JIALI; ROLLINS, LISA A.; HUYE, LESLIE L.; FANG, JIAN; DANDEKAR, VARADA; MEI, ZHUYONG; JACKSON, KIMBERLEY; VERA, JUAN; ANDO, JUN; NGO, MINHTRAN C.; COUSTAN-SMITH, ELAINE; CAMPANA, DARIO; SZMANIA, SUSANN; GARG, TARUN; MORENO-BOST, AMBERLY; VANRHEE, FRITS; GEE, ADRIAN P.; ROONEY, CLIONA M.

2016-01-01

Background aims Interest in natural killer (NK) cell-based immunotherapy has resurged since new protocols for the purification and expansion of large numbers of clinical-grade cells have become available. Methods We have successfully adapted a previously described NK expansion method that uses K562 cells expressing interleukin (IL)-15 and 4-1 BB Ligand (BBL) (K562-mb15-41BBL) to grow NK cells in novel gas-permeable static cell culture flasks (G-Rex). Results Using this system we produced up to 19 × 109 functional NK cells from unseparated apheresis products, starting with 15 × 107 CD3− CD56+ NK cells, within 8–10 days of culture. The G-Rex yielded a higher fold expansion of NK cells than conventional gas-permeable bags and required no cell manipulation or feeding during the culture period. We also showed that K562-mb15-41BBL cells up-regulated surface HLA class I antigen expression upon stimulation with the supernatants from NK cultures and stimulated alloreactive CD8+ T cells within the NK cultures. However, these CD3+ T cells could be removed successfully using the CliniMACS system. We describe our optimized NK cell cryopreservation method and show that the NK cells are viable and functional even after 12 months of cryopreservation. Conclusions We have successfully developed a static culture protocol for large-scale expansion of NK cells in the gas permeable G-Rex system under good manufacturing practice (GMP) conditions. This strategy is currently being used to produce NK cells for cancer immunotherapy. PMID:22900959

An improved method for design of expansion-chamber mufflers with application to an operational helicopter

NASA Technical Reports Server (NTRS)

Parrott, T. L.

1973-01-01

An improved method for the design of expansion-chamber mufflers is described and applied to the task of reducing exhaust noise generated by a helicopter. The method is an improvement of standard transmission-line theory in that it accounts for the effect of the mean exhaust-gas flow on the acoustic-transmission properties of a muffler system, including the termination boundary condition. The method has been computerized, and the computer program includes an optimization procedure that adjusts muffler component lengths to achieve a minimum specified desired transmission loss over a specified frequency range. A printout of the program is included together with a user-oriented description.

A general moment expansion method for stochastic kinetic models

NASA Astrophysics Data System (ADS)

Ale, Angelique; Kirk, Paul; Stumpf, Michael P. H.

2013-05-01

Moment approximation methods are gaining increasing attention for their use in the approximation of the stochastic kinetics of chemical reaction systems. In this paper we derive a general moment expansion method for any type of propensities and which allows expansion up to any number of moments. For some chemical reaction systems, more than two moments are necessary to describe the dynamic properties of the system, which the linear noise approximation is unable to provide. Moreover, also for systems for which the mean does not have a strong dependence on higher order moments, moment approximation methods give information about higher order moments of the underlying probability distribution. We demonstrate the method using a dimerisation reaction, Michaelis-Menten kinetics and a model of an oscillating p53 system. We show that for the dimerisation reaction and Michaelis-Menten enzyme kinetics system higher order moments have limited influence on the estimation of the mean, while for the p53 system, the solution for the mean can require several moments to converge to the average obtained from many stochastic simulations. We also find that agreement between lower order moments does not guarantee that higher moments will agree. Compared to stochastic simulations, our approach is numerically highly efficient at capturing the behaviour of stochastic systems in terms of the average and higher moments, and we provide expressions for the computational cost for different system sizes and orders of approximation. We show how the moment expansion method can be employed to efficiently quantify parameter sensitivity. Finally we investigate the effects of using too few moments on parameter estimation, and provide guidance on how to estimate if the distribution can be accurately approximated using only a few moments.

Character expansion methods for matrix models of dually weighted graphs

NASA Astrophysics Data System (ADS)

Kazakov, Vladimir A.; Staudacher, Matthias; Wynter, Thomas

1996-04-01

We consider generalized one-matrix models in which external fields allow control over the coordination numbers on both the original and dual lattices. We rederive in a simple fashion a character expansion formula for these models originally due to Itzykson and Di Francesco, and then demonstrate how to take the large N limit of this expansion. The relationship to the usual matrix model resolvent is elucidated. Our methods give as a by-product an extremely simple derivation of the Migdal integral equation describing the large N limit of the Itzykson-Zuber formula. We illustrate and check our methods by analysing a number of models solvable by traditional means. We then proceed to solve a new model: a sum over planar graphys possessing even coordination numbers on both the original and the dual lattice. We conclude by formulating the equations for the case of arbitrary sets of even, self-dual coupling constants. This opens the way for studying the deep problems of phase transitions from random to flat lattices. January 1995

The fifth-order partial differential equation for the description of the α + β Fermi-Pasta-Ulam model

NASA Astrophysics Data System (ADS)

Kudryashov, Nikolay A.; Volkov, Alexandr K.

2017-01-01

We study a new nonlinear partial differential equation of the fifth order for the description of perturbations in the Fermi-Pasta-Ulam mass chain. This fifth-order equation is an expansion of the Gardner equation for the description of the Fermi-Pasta-Ulam model. We use the potential of interaction between neighbouring masses with both quadratic and cubic terms. The equation is derived using the continuous limit. Unlike the previous works, we take into account higher order terms in the Taylor series expansions. We investigate the equation using the Painlevé approach. We show that the equation does not pass the Painlevé test and can not be integrated by the inverse scattering transform. We use the logistic function method and the Laurent expansion method to find travelling wave solutions of the fifth-order equation. We use the pseudospectral method for the numerical simulation of wave processes, described by the equation.

Crystalline phases by an improved gradient expansion technique

NASA Astrophysics Data System (ADS)

Carignano, S.; Mannarelli, M.; Anzuini, F.; Benhar, O.

2018-02-01

We develop an innovative technique for studying inhomogeneous phases with a spontaneous broken symmetry. The method relies on the knowledge of the exact form of the free energy in the homogeneous phase and on a specific gradient expansion of the order parameter. We apply this method to quark matter at vanishing temperature and large chemical potential, which is expected to be relevant for astrophysical considerations. The method is remarkably reliable and fast as compared to performing the full numerical diagonalization of the quark Hamiltonian in momentum space and is designed to improve the standard Ginzburg-Landau expansion close to the phase transition points. For definiteness, we focus on inhomogeneous chiral symmetry breaking, accurately reproducing known results for one-dimensional and two-dimensional modulations and examining novel crystalline structures, as well. Consistently with previous results, we find that the energetically favored modulation is the so-called one-dimensional real-kink crystal. We propose a qualitative description of the pairing mechanism to motivate this result.

Creative Writing and Schiller's Aesthetic Education

ERIC Educational Resources Information Center

Howarth, Peter

2007-01-01

For academics committed to the idea of an all-round aesthetic education, one of the great successes of the last thirty years has been the tremendous expansion of creative writing classes. Despite the dramatic expansion of creative writing as an academic discipline, the methods, ideals, and values of creative writing workshops have very often been…

System and method for slurry handling

DOEpatents

Steele, Raymond Douglas; Oppenheim, Judith Pauline

2015-12-29

A system includes a slurry depressurizing system that includes a liquid expansion system configured to continuously receive a slurry at a first pressure and continuously discharge the slurry at a second pressure. For example, the slurry depressurizing system may include an expansion turbine to expand the slurry from the first pressure to the second pressure.

An Improved Heaviside Approach to Partial Fraction Expansion and Its Applications

ERIC Educational Resources Information Center

Man, Yiu-Kwong

2009-01-01

In this note, we present an improved Heaviside approach to compute the partial fraction expansions of proper rational functions. This method uses synthetic divisions to determine the unknown partial fraction coefficients successively, without the need to use differentiation or to solve a system of linear equations. Examples of its applications in…

Perturbative description of the fermionic projector: Normalization, causality, and Furry's theorem

NASA Astrophysics Data System (ADS)

Finster, Felix; Tolksdorf, Jürgen

2014-05-01

The causal perturbation expansion of the fermionic projector is performed with a contour integral method. Different normalization conditions are analyzed. It is shown that the corresponding light-cone expansions are causal in the sense that they only involve bounded line integrals. For the resulting loop diagrams we prove a generalized Furry theorem.

A Systematic Approach to Determining the Identifiability of Multistage Carcinogenesis Models.

PubMed

Brouwer, Andrew F; Meza, Rafael; Eisenberg, Marisa C

2017-07-01

Multistage clonal expansion (MSCE) models of carcinogenesis are continuous-time Markov process models often used to relate cancer incidence to biological mechanism. Identifiability analysis determines what model parameter combinations can, theoretically, be estimated from given data. We use a systematic approach, based on differential algebra methods traditionally used for deterministic ordinary differential equation (ODE) models, to determine identifiable combinations for a generalized subclass of MSCE models with any number of preinitation stages and one clonal expansion. Additionally, we determine the identifiable combinations of the generalized MSCE model with up to four clonal expansion stages, and conjecture the results for any number of clonal expansion stages. The results improve upon previous work in a number of ways and provide a framework to find the identifiable combinations for further variations on the MSCE models. Finally, our approach, which takes advantage of the Kolmogorov backward equations for the probability generating functions of the Markov process, demonstrates that identifiability methods used in engineering and mathematics for systems of ODEs can be applied to continuous-time Markov processes. © 2016 Society for Risk Analysis.

Optimization of auxiliary basis sets for the LEDO expansion and a projection technique for LEDO-DFT.

PubMed

Götz, Andreas W; Kollmar, Christian; Hess, Bernd A

2005-09-01

We present a systematic procedure for the optimization of the expansion basis for the limited expansion of diatomic overlap density functional theory (LEDO-DFT) and report on optimized auxiliary orbitals for the Ahlrichs split valence plus polarization basis set (SVP) for the elements H, Li--F, and Na--Cl. A new method to deal with near-linear dependences in the LEDO expansion basis is introduced, which greatly reduces the computational effort of LEDO-DFT calculations. Numerical results for a test set of small molecules demonstrate the accuracy of electronic energies, structural parameters, dipole moments, and harmonic frequencies. For larger molecular systems the numerical errors introduced by the LEDO approximation can lead to an uncontrollable behavior of the self-consistent field (SCF) process. A projection technique suggested by Löwdin is presented in the framework of LEDO-DFT, which guarantees for SCF convergence. Numerical results on some critical test molecules suggest the general applicability of the auxiliary orbitals presented in combination with this projection technique. Timing results indicate that LEDO-DFT is competitive with conventional density fitting methods. (c) 2005 Wiley Periodicals, Inc.

Self-expansion is associated with better adherence and obesity treatment outcomes in adults

PubMed Central

Xu, Xiaomeng; Leahey, Tricia M.; Boguszewski, Katherine; Krupel, Katie; Mailloux, Kimberly A.; Wing, Rena R.

2016-01-01

Background Previous studies have shown that self-expansion (e.g., increasing positive self-content via engaging in novel, rewarding activities) is associated with smoking cessation and attenuated cigarette cue-reactivity. Purpose This study examined whether self-expansion is associated with better adherence, weight loss, and physical activity (PA) outcomes within a weight loss intervention. Methods Participants from Shape Up Rhode Island 2012, a Web-based community wellness initiative, took part in a randomized controlled trial that involved a 12-week behavioral weight loss intervention (1). At baseline and post-intervention, objective weights and self-reported self-expansion and PA were obtained from 239 participants. Treatment adherence was assessed objectively. Results Self-expansion during treatment was significantly associated with percent weight loss including clinically significant weight loss (i.e. 5%), minutes of PA, and treatment adherence. These results held after controlling for relevant covariates. Conclusions This is the first study to show that self-expansion is associated with better behavioral weight loss outcomes including weight loss, adherence, and PA. These results suggest that self-expansion is a promising novel target for future research which could inform health interventions. PMID:27436226

Instantaneous Frequency Analysis on Nonlinear EMIC Emissions: Arase Observation

NASA Astrophysics Data System (ADS)

Shoji, M.; Yoshizumi, M.; Omura, Y.; Kasaba, Y.; Ishisaka, K.; Matsuda, S.; Kasahara, Y.; Yagitani, S.; Matsuoka, A.; Teramoto, M.; Takashima, T.; Shinohara, I.

2017-12-01

In the inner magnetosphere, electromagnetic ion cyclotron (EMIC) waves cause nonlinear interactions with energetic protons. The waves drastically modify the proton distribution function, resulting in the particle loss in the radiation belt. Arase spacecraft, launched in late 2016, observed a nonlinear EMIC falling tone emission in the high magnetic latitude (MLAT) region of the inner magnetosphere. The wave growth with sub-packet structures of the falling tone emission is found by waveform data from PWE/EFD instrument. The evolution of the instantaneous frequency of the electric field of the EMIC falling tone emission is analyzed by Hilbert-Huang transform (HHT). We find several sub-packets with rising frequency in the falling tone wave. A self-consistent hybrid simulation suggested the complicate frequency evolution of the EMIC sub-packet emissions in the generation region. The intrinsic mode functions of Arase data derived from HHT are compared with the simulation data. The origin of the falling tone emission in the high MLAT region is also discussed.

Analytical model of cracking due to rebar corrosion expansion in concrete considering the structure internal force

NASA Astrophysics Data System (ADS)

Lin, Xiangyue; Peng, Minli; Lei, Fengming; Tan, Jiangxian; Shi, Huacheng

2017-12-01

Based on the assumptions of uniform corrosion and linear elastic expansion, an analytical model of cracking due to rebar corrosion expansion in concrete was established, which is able to consider the structure internal force. And then, by means of the complex variable function theory and series expansion technology established by Muskhelishvili, the corresponding stress component functions of concrete around the reinforcement were obtained. Also, a comparative analysis was conducted between the numerical simulation model and present model in this paper. The results show that the calculation results of both methods were consistent with each other, and the numerical deviation was less than 10%, proving that the analytical model established in this paper is reliable.

Behind the mask of method: political orientation and constitutional interpretive preferences.

PubMed

Furgeson, Joshua R; Babcock, Linda; Shane, Peter M

2008-12-01

Debate about how to best interpret the Constitution often revolves around interpretive methodologies (e.g., originalism or expansive interpretation). This article examines whether individuals' political orientation influences the methodologies they prefer to use to interpret the Constitution. We study this proposed relationship using a survey of federal law clerks and an experimental study with college students. The survey results indicate that, compared to conservatives, liberal clerks prefer the current meaning or the most plausible appealing meaning of the constitutional text, while conservatives prefer the original meaning of the text. Liberal clerks also prefer to interpret the Constitution much more expansively. The second study manipulates the policy implications of expansive interpretation and finds this manipulation differentially affects liberals' and conservatives' expansiveness preferences.

Monitoring the corrosion process of reinforced concrete using BOTDA and FBG sensors.

PubMed

Mao, Jianghong; Chen, Jiayun; Cui, Lei; Jin, Weiliang; Xu, Chen; He, Yong

2015-04-15

Expansion and cracking induced by the corrosion of reinforcement concrete is the major factor in the failure of concrete durability. Therefore, monitoring of concrete cracking is critical for evaluating the safety of concrete structures. In this paper, we introduce a novel monitoring method combining Brillouin optical time domain analysis (BOTDA) and fiber Bragg grating (FBG), based on mechanical principles of concrete expansion cracking. BOTDA monitors concrete expansion and crack width, while FBG identifies the time and position of cracking. A water-pressure loading simulation test was carried out to determine the relationship between fiber strain, concrete expansion and crack width. An electrical accelerated corrosion test was also conducted to evaluate the ability of this novel sensor to monitor concrete cracking under practical conditions.

Estimation of regional lung expansion via 3D image registration

NASA Astrophysics Data System (ADS)

Pan, Yan; Kumar, Dinesh; Hoffman, Eric A.; Christensen, Gary E.; McLennan, Geoffrey; Song, Joo Hyun; Ross, Alan; Simon, Brett A.; Reinhardt, Joseph M.

2005-04-01

A method is described to estimate regional lung expansion and related biomechanical parameters using multiple CT images of the lungs, acquired at different inflation levels. In this study, the lungs of two sheep were imaged utilizing a multi-detector row CT at different lung inflations in the prone and supine positions. Using the lung surfaces and the airway branch points for guidance, a 3D inverse consistent image registration procedure was used to match different lung volumes at each orientation. The registration was validated using a set of implanted metal markers. After registration, the Jacobian of the deformation field was computed to express regional expansion or contraction. The regional lung expansion at different pressures and different orientations are compared.

Preparation and structure of BiCrTeO{sub 6}: A new compound in Bi–Cr–Te–O system. Thermal expansion studies of Cr{sub 2}TeO{sub 6}, Bi{sub 2}TeO{sub 6} and BiCrTeO{sub 6}

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

Vats, Bal Govind; Phatak, Rohan; Krishnan, K.

Graphical abstract: A new compound BiCrTeO{sub 6} in the Bi–Cr–Te–O system was prepared by solid state route and characterized by X-ray diffraction method. The crystal structure of BiCrTeO{sub 6} shows that there is one distinct site for bismuth (Bi) atom (pink color), one chromium rich (Cr/Te = 68/32) (blue/green color), one tellurium rich (Te/Cr = 68/32) sites (green/blue color), and one distinct site for oxygen (O) atom (red color) in the unit cell. All cations in this structure show an octahedral coordination with oxygen atoms at the corners. The thermogram (TG) of the compound in air shows that it ismore » stable up to 1103 K and decomposes thereafter. The thermal expansion behaviour of BiCrTeO{sub 6} was studied using high temperature X-ray diffraction method from room temperature to 923 K under vacuum of 10{sup −8} atmosphere and showed positive thermal expansion with the average volume thermal expansion coefficients of 16.0 × 10{sup −6}/K. - Highlights: • A new compound BiCrTeO{sub 6} in Bi–Cr–Te–O system was prepared and characterized. • The crystal structure of BiCrTeO{sub 6} was determined by Rietveld refinement method. • The structure of BiCrTeO{sub 6} shows an octahedral coordination for all the metal ions. • The thermal expansion behavior of BiCrTeO{sub 6} from room temperature to 923 K showed a positive thermal expansion. • The average volume thermal expansion coefficient for BiCrTeO{sub 6} is 16.0 × 10{sup −6}/K. - Abstract: A new compound BiCrTeO{sub 6} in Bi–Cr–Te–O system was prepared by solid state reaction of Bi{sub 2}O{sub 3}, Cr{sub 2}O{sub 3} and H{sub 6}TeO{sub 6} in oxygen and characterized by X-ray diffraction (XRD) method. It could be indexed on a trigonal lattice, with the space group P-31c, unit cell parameters a = 5.16268(7) Å and c = 9.91861(17) Å. The crystal structure of BiCrTeO{sub 6} was determined by Rietveld refinement method using the powder XRD data. Structure shows that there is one distinct site for bismuth (Bi) atom, one chromium rich (Cr/Te = 68/32), and one tellurium rich (Te/Cr = 68/32) sites, and one distinct site for oxygen (O) atom in the unit cell. All cations in this structure show an octahedral coordination with oxygen atoms at the corners. The thermogravimetric analysis (TGA) of the compound in air shows that it is stable up to 1103 K and decomposes thereafter. The thermal expansion behavior of Cr{sub 2}TeO{sub 6}, Bi{sub 2}TeO{sub 6} and BiCrTeO{sub 6} was studied using High Temperature X-ray diffraction (HTXRD) method from room temperature to 973, 873 and 923 K respectively under vacuum of 10{sup −8} atmospheres. All the compounds showed positive thermal expansion with the average volume thermal expansion coefficients of 14.38 × 10{sup −6}/K, 22.0 × 10{sup −6}/K and 16.0 × 10{sup −6}/K respectively.« less

Deblurring of Class-Averaged Images in Single-Particle Electron Microscopy.

PubMed

Park, Wooram; Madden, Dean R; Rockmore, Daniel N; Chirikjian, Gregory S

2010-03-01

This paper proposes a method for deblurring of class-averaged images in single-particle electron microscopy (EM). Since EM images of biological samples are very noisy, the images which are nominally identical projection images are often grouped, aligned and averaged in order to cancel or reduce the background noise. However, the noise in the individual EM images generates errors in the alignment process, which creates an inherent limit on the accuracy of the resulting class averages. This inaccurate class average due to the alignment errors can be viewed as the result of a convolution of an underlying clear image with a blurring function. In this work, we develop a deconvolution method that gives an estimate for the underlying clear image from a blurred class-averaged image using precomputed statistics of misalignment. Since this convolution is over the group of rigid body motions of the plane, SE(2), we use the Fourier transform for SE(2) in order to convert the convolution into a matrix multiplication in the corresponding Fourier space. For practical implementation we use a Hermite-function-based image modeling technique, because Hermite expansions enable lossless Cartesian-polar coordinate conversion using the Laguerre-Fourier expansions, and Hermite expansion and Laguerre-Fourier expansion retain their structures under the Fourier transform. Based on these mathematical properties, we can obtain the deconvolution of the blurred class average using simple matrix multiplication. Tests of the proposed deconvolution method using synthetic and experimental EM images confirm the performance of our method.

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

Beaucage, Timothy R; Beenfeldt, Eric P; Speakman, Scott A

Among the langasite family of crystals (LGX), the three most popular materials are langasite (LGS, La3Ga5SiO14), langatate (LGT, La3Ga5.5Ta0.5O14) and langanite (LGN, La3Ga5.5Nb0.5O14). The LGX crystals have received significant attention for acoustic wave (AW) device applications due to several properties, which include: (1) piezoelectric constants about two and a half times those of quartz, thus allowing the design of larger bandwidth filters; (2) existence of temperature compensated orientations; (3) high density, with potential for reduced vibration and acceleration sensitivity; and (4) possibility of operation at high temperatures, since the LGX crystals do not present phase changes up to their meltingmore » point above 1400degC. The LGX crystals' capability to operate at elevated temperatures calls for an investigation on the growth quality and the consistency of these materials' properties at high temperature. One of the fundamental crystal properties is the thermal expansion coefficients in the entire temperature range where the material is operational. This work focuses on the measurement of the LGT thermal expansion coefficients from room temperature (25degC) to 1200degC. Two methods of extracting the thermal expansion coefficients have been used and compared: (a) dual push-rod dilatometry, which provides the bulk expansion; and (b) x-ray powder diffraction, which provides the lattice expansion. Both methods were performed over the entire temperature range and considered multiple samples taken from <001> Czochralski grown LGT material. The thermal coefficients of expansion were extracted by approximating each expansion data set to a third order polynomial fit over three temperature ranges reported in this work: 25degC to 400degC, 400degC to 900degC, 900degC to 1200degC. An accuracy of fit better than 35ppm for the bulk expansion and better than 10ppm for the lattice expansion have been obtained with the aforementioned polynomial fitting. The percentage difference between the bulk and the lattice fitted expansion responses over the entire temperature range of 25degC to 1200degC is less than 2% for the three crystalline axes, which indicates the high quality and growth consistency of the LGT crystal measured« less