20 CFR 416.535 - Underpayments and overpayments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... whose drug addiction or alcoholism is a contributing factor material to the determination of disability. When an individual whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.535 - Underpayments and overpayments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... whose drug addiction or alcoholism is a contributing factor material to the determination of disability. When an individual whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.535 - Underpayments and overpayments.

Code of Federal Regulations, 2012 CFR

2012-04-01

... whose drug addiction or alcoholism is a contributing factor material to the determination of disability. When an individual whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.535 - Underpayments and overpayments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... whose drug addiction or alcoholism is a contributing factor material to the determination of disability. When an individual whose drug addiction or alcoholism is a contributing factor material to the...

Repeatedly measured material and behavioral factors changed the explanation of socioeconomic inequalities in all-cause mortality.

PubMed

Oude Groeniger, Joost; Kamphuis, Carlijn B; Mackenbach, Johan P; van Lenthe, Frank J

2017-11-01

We examined whether using repeatedly measured material and behavioral factors contributed differently to socioeconomic inequalities in all-cause mortality compared to one baseline measurement. Data from the Dutch prospective GLOBE cohort were linked to mortality register data (1991-2013; N = 4,851). Socioeconomic position was measured at baseline by educational level and occupation. Material factors (financial difficulties, housing tenure, health insurance) and behavioral factors (smoking, leisure time physical activity, sports participation, and body mass index) were self-reported in 1991, 1997, and 2004. Cox proportional hazards regression and bootstrap methods were used to examine the contribution of baseline-only and time-varying risk factors to socioeconomic inequalities in mortality. Men and women in the lowest educational and occupational groups were at an increased risk of dying compared to the highest groups. The contribution of material factors to socioeconomic inequalities in mortality was smaller when multiple instead of baseline-only measurements were used (25%-65% vs. 49%-93%). The contribution of behavioral factors was larger when multiple measurements were used (39%-51% vs. 19%-40%). Inclusion of time-dependent risk factors contributes to understanding socioeconomic inequalities in mortality, but careful examination of the underlying mechanisms and suitability of the model is required. Copyright © 2017 Elsevier Inc. All rights reserved.

Factors influencing pre-service physics teachers' skills of writing teaching materials

NASA Astrophysics Data System (ADS)

Sinaga, Parlindungan

2016-02-01

Writing teaching materials is one of the generic pedagogical skills. Teachers and pre-service teachers should be trained to have the skills of writing teaching materials. This study examines the factors that influence the skills of writing in the disciplines among pre-service physics teachers. This study in particular aims to contribute to the development of science writing in the disciplines and to the organization of workshops on writing teaching materials for pre-service teachers. The problems of this research are formulated in the question of what are the factors that influence the skills of pre-service physics teachers in writing teaching materials. The research adopted mixed methods with embedded experimental design. The research subjects were 18 students enrolled in the school physics course. The instruments used consisted of conceptual understanding tests, learning strategy questionnaire, tests of the multiple representation skills, and one-on-one semi- structured interview. Results of data analysis show that the ability and skills of writing physics teaching materials of the pre- service physics teachers are determined by the factors of conceptual understanding of the subject matter with a contribution of 20%, the skills of making multiple representations of concepts with a contribution of 9.8% and students' self-regulation and learning strategy with a contribution of 33.5%. There are other factors that have not been investigated in this study; therefore, it is recommended that future research conduct further investigation on other factors that influence pre-service teachers' skills in writing physics teaching materials.

Educational inequalities in general and mental health: differential contribution of physical activity, smoking, alcohol consumption and diet.

PubMed

Kurtze, Nanna; Eikemo, Terje A; Kamphuis, Carlijn B M

2013-04-01

Behavioural, material and psychosocial risk factors may explain educational inequalities in general health. To what extent these risk factors have similar or different contributions to educational inequalities in mental health is unknown. Data were derived from the Norwegian Survey of Level of Living from 2005, comprising 5791 respondents aged ≥ 25 years. The study objectives were addressed by means of a series of logistic regression analyses in which we examined: (i) educational inequalities in self-reported general and mental health; (ii) the associations between behavioural, material and psychosocial risk factors and general and mental health, controlled for sex, age and education; and (iii) the contribution of risk factors to the observed health gradients. The lower educated were more likely to be in poor health [odds ratio (OR): 3.46 (95% confidence interval, CI: 2.84-4.21)] and to be in poor mental health [OR: 1.41 (95% CI: 1.12-1.78)] than the highest educated. The joint contribution of behavioural, material and psychosocial risk factors explained all the variations of mental health inequalities, whereas these were able to explain ~40% of the inequalities in general health. Both behavioural and material risk factors contributed substantially to the explanation of general and mental health inequalities, whereas the psychosocial risk factor (i.e. having close persons to communicate with) only seemed to make a larger difference for the explanation of mental health inequalities. Policies and interventions to reduce health inequalities should have a broad focus. Combined strategies should be applied to improve physical activity, decrease smoking and improve material and psychosocial conditions among lower educated groups, to achieve the true potential of reducing inequalities in both general and mental health.

20 CFR 404.1535 - How we will determine whether your drug addiction or alcoholism is a contributing factor material...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How we will determine whether your drug addiction or alcoholism is a contributing factor material to the determination of disability. 404.1535 Section 404.1535 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining Disability...

20 CFR 416.935 - How we will determine whether your drug addiction or alcoholism is a contributing factor material...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How we will determine whether your drug addiction or alcoholism is a contributing factor material to the determination of disability. 416.935 Section 416.935 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability...

20 CFR 404.315 - Who is entitled to disability benefits?

Code of Federal Regulations, 2013 CFR

2013-04-01

... against reentitlement to disability benefits if drug addiction or alcoholism is a contributing factor... drug addiction or alcoholism is a contributing factor material to the determination of disability and...

20 CFR 404.315 - Who is entitled to disability benefits?

Code of Federal Regulations, 2014 CFR

2014-04-01

... against reentitlement to disability benefits if drug addiction or alcoholism is a contributing factor... drug addiction or alcoholism is a contributing factor material to the determination of disability and...

20 CFR 404.315 - Who is entitled to disability benefits?

Code of Federal Regulations, 2012 CFR

2012-04-01

... against reentitlement to disability benefits if drug addiction or alcoholism is a contributing factor... drug addiction or alcoholism is a contributing factor material to the determination of disability and...

20 CFR 404.315 - Who is entitled to disability benefits?

Code of Federal Regulations, 2011 CFR

2011-04-01

... against reentitlement to disability benefits if drug addiction or alcoholism is a contributing factor... drug addiction or alcoholism is a contributing factor material to the determination of disability and...

20 CFR 416.214 - You are disabled and drug addiction or alcoholism is a contributing factor material to the...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false You are disabled and drug addiction or alcoholism is a contributing factor material to the determination of disability. 416.214 Section 416.214 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Eligibility Reasons Why You May Not...

20 CFR 404.350 - Who is entitled to child's benefits?

Code of Federal Regulations, 2014 CFR

2014-04-01

..., and your disability was based on a finding that drug addiction or alcoholism was a contributing factor... months, drug addiction or alcoholism is a contributing factor material to the later determination of...

20 CFR 404.350 - Who is entitled to child's benefits?

Code of Federal Regulations, 2012 CFR

2012-04-01

..., and your disability was based on a finding that drug addiction or alcoholism was a contributing factor... months, drug addiction or alcoholism is a contributing factor material to the later determination of...

20 CFR 404.350 - Who is entitled to child's benefits?

Code of Federal Regulations, 2011 CFR

2011-04-01

..., and your disability was based on a finding that drug addiction or alcoholism was a contributing factor... months, drug addiction or alcoholism is a contributing factor material to the later determination of...

20 CFR 404.350 - Who is entitled to child's benefits?

Code of Federal Regulations, 2013 CFR

2013-04-01

..., and your disability was based on a finding that drug addiction or alcoholism was a contributing factor... months, drug addiction or alcoholism is a contributing factor material to the later determination of...

Contribution of material, occupational, and psychosocial factors in the explanation of social inequalities in health in 28 countries in Europe.

PubMed

Aldabe, B; Anderson, R; Lyly-Yrjänäinen, M; Parent-Thirion, A; Vermeylen, G; Kelleher, C C; Niedhammer, I

2011-12-01

To analyse the associations between socio-economic status (SES), measured using occupation, and self-reported health, and to examine the contribution of various material, occupational and psychosocial factors to social inequalities in health in Europe. This study was based on data from the European Quality of Life Survey (EQLS) carried out in 2003. The total sample consisted of 6038 and 6383 working men and women in 28 countries in Europe (response rates: 30.3-91.2%). Each set of potential material, occupational and psychosocial mediators included between eight and 11 variables. Statistical analysis was performed using multilevel logistic regression analysis. Significant social differences were observed for self-reported health, manual workers being more likely to be in poor health (OR=1.89, 95% CI 1.46 to 2.46 for men, OR=2.18, 95% CI 1.71 to 2.77 for women). Strong social gradients were found for almost all potential mediating factors, and almost all displayed significant associations with self-reported health. Social differences in health were substantially reduced after adjustment for material, occupational and psychosocial factors, with material factors playing a major role. The four strongest contributions to reducing these differences were found for material deprivation, social exclusion, financial problems and job reward. Taking all mediators into account led to an explanation of the social differences in health by 78-100% for men and women. The association between SES and poor health may be attributed to differential distributions of several dimensions of material, occupational and psychosocial conditions across occupational groups. Interventions targeting different dimensions might result in a reduction in social inequalities in health.

20 CFR 416.936 - Treatment required for individuals whose drug addiction or alcoholism is a contributing factor...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Treatment required for individuals whose drug addiction or alcoholism is a contributing factor material to the determination of disability. 416.936 Section 416.936 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Determining...

20 CFR 404.1536 - Treatment required for individuals whose drug addiction or alcoholism is a contributing factor...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Treatment required for individuals whose drug addiction or alcoholism is a contributing factor material to the determination of disability. 404.1536 Section 404.1536 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Determining...

Quasiparticle band gap of organic-inorganic hybrid perovskites: Crystal structure, spin-orbit coupling, and self-energy effects

NASA Astrophysics Data System (ADS)

Gao, Weiwei; Gao, Xiang; Abtew, Tesfaye A.; Sun, Yi-Yang; Zhang, Shengbai; Zhang, Peihong

2016-02-01

The quasiparticle band gap is one of the most important materials properties for photovoltaic applications. Often the band gap of a photovoltaic material is determined (and can be controlled) by various factors, complicating predictive materials optimization. An in-depth understanding of how these factors affect the size of the gap will provide valuable guidance for new materials discovery. Here we report a comprehensive investigation on the band gap formation mechanism in organic-inorganic hybrid perovskites by decoupling various contributing factors which ultimately determine their electronic structure and quasiparticle band gap. Major factors, namely, quasiparticle self-energy, spin-orbit coupling, and structural distortions due to the presence of organic molecules, and their influences on the quasiparticle band structure of organic-inorganic hybrid perovskites are illustrated. We find that although methylammonium cations do not contribute directly to the electronic states near band edges, they play an important role in defining the band gap by introducing structural distortions and controlling the overall lattice constants. The spin-orbit coupling effects drastically reduce the electron and hole effective masses in these systems, which is beneficial for high carrier mobilities and small exciton binding energies.

20 CFR 404.335 - How do I become entitled to widow's or widower's benefits?

Code of Federal Regulations, 2012 CFR

2012-04-01

... received 36 months of payments based on disability when drug addiction or alcoholism was a contributing... benefits is not based on a disability where drug addiction or alcoholism is a contributing factor material...

20 CFR 404.335 - How do I become entitled to widow's or widower's benefits?

Code of Federal Regulations, 2013 CFR

2013-04-01

... received 36 months of payments based on disability when drug addiction or alcoholism was a contributing... benefits is not based on a disability where drug addiction or alcoholism is a contributing factor material...

20 CFR 404.335 - How do I become entitled to widow's or widower's benefits?

Code of Federal Regulations, 2014 CFR

2014-04-01

... received 36 months of payments based on disability when drug addiction or alcoholism was a contributing... benefits is not based on a disability where drug addiction or alcoholism is a contributing factor material...

20 CFR 404.335 - How do I become entitled to widow's or widower's benefits?

Code of Federal Regulations, 2011 CFR

2011-04-01

... received 36 months of payments based on disability when drug addiction or alcoholism was a contributing... benefits is not based on a disability where drug addiction or alcoholism is a contributing factor material...

10 CFR 70.50 - Reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... requires unplanned medical treatment at a medical facility of an individual with spreadable radioactive... material or any device, container, or equipment containing licensed material when: (i) The quantity of... all factors that contributed to the event and the manufacturer and model number (if applicable) of any...

10 CFR 70.50 - Reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... requires unplanned medical treatment at a medical facility of an individual with spreadable radioactive... material or any device, container, or equipment containing licensed material when: (i) The quantity of... all factors that contributed to the event and the manufacturer and model number (if applicable) of any...

15 CFR 904.204 - Duties and powers of Judge.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the determination and whether the requester can be expected to contribute materially to the..., or denial of permit application, taking into account all of the factors required by applicable law... part, and such failure to comply: (i) Materially injures or prejudices another party by causing...

15 CFR 904.204 - Duties and powers of Judge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the determination and whether the requester can be expected to contribute materially to the..., or denial of permit application, taking into account all of the factors required by applicable law... part, and such failure to comply: (i) Materially injures or prejudices another party by causing...

15 CFR 904.204 - Duties and powers of Judge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the determination and whether the requester can be expected to contribute materially to the..., or denial of permit application, taking into account all of the factors required by applicable law... part, and such failure to comply: (i) Materially injures or prejudices another party by causing...

15 CFR 904.204 - Duties and powers of Judge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the determination and whether the requester can be expected to contribute materially to the..., or denial of permit application, taking into account all of the factors required by applicable law... part, and such failure to comply: (i) Materially injures or prejudices another party by causing...

Carpet in Schools: Myth and Reality.

ERIC Educational Resources Information Center

Chan, T. C.; Richardson, Michael D.; Jording, Cathy

2001-01-01

Carpet can serve as a type of finish over concrete, improves the acoustical environment, and helps build a more conducive, personalized learning environment. Problems associated with carpeting are related to raw materials, texture, cleaning materials, cost factors, moisture, and alleged contribution to poor indoor air quality. Recommendations are…

Matching Classroom Instruction with Reading Abilities: An Unmet Need.

ERIC Educational Resources Information Center

Durkin, Dolores

1990-01-01

This article discusses a widespread failure of schools to match reading instruction to children's needs, identifying large class sizes, dependence on basal reader programs and questionable testing practices as contributing factors. Basal materials are seen as contributing to standardized curricula and impeding efforts to shift teacher behavior…

Happy Objects, Happy Men? Affect and Materiality in Vocational Training

ERIC Educational Resources Information Center

Åberg, Magnus; Hedlin, Maria

2015-01-01

This article investigates the prevailing social inertia of vocational training. Previous research indicates that gendered social norms contribute to sustaining gender segregation. Few studies, however, have paid attention to how the interplay of emotional and material factors impact on gender norms in vocational training. The article builds on an…

ATMOSPHERIC AEROSOL SOURCE-RECEPTOR RELATIONSHIPS: THE ROLE OF COAL-FIRED POWER PLANTS

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

Allen L. Robinson; Spyros N. Pandis; Cliff I. Davidson

2005-04-01

This report describes the technical progress made on the Pittsburgh Air Quality Study (PAQS) during the period of September 2004 through February 2005. Significant progress was made this project period on the analysis of ambient data, source apportionment, and deterministic modeling activities. The major experimental achievement this project period was the characterization of the mercury and fine particle emissions from two modern, large, commercial pulverized coal boilers. This testing completes the field work component of the Source Characterization Activity. This report highlights results from mercury emission measurements made using a dilution sampler. The measurements clearly indicate that mercury is beingmore » transformed from an oxidized to an elemental state within the dilution. However, wall effects are significant making it difficult to determine whether or not these changes occur in the gas phase or due to some interaction with the sampler walls. This report also presents results from an analysis that uses spherical aluminum silicate (SAS) particles as a marker for primary PM{sub 2.5} emitted from coal combustion. Primary emissions from coal combustion contribute only a small fraction of the PM{sub 2.5} mass (less than 1.5% in the summer and less than 3% in the winter) at the Pittsburgh site. Ambient SAS concentrations also appear to be reasonably spatially homogeneous. Finally, SAS emission factors measured at pilot-scale are consistent with measurements made at full-scale. This report also presents results from applying the Unmix and PMF models to estimate the contribution of different sources to the PM{sub 2.5} mass concentrations in Pittsburgh using aerosol composition information. Comparison of the two models shows similar source composition and contribution for five factors: crustal material, nitrate, an Fe, Mn, and Zn factor, specialty steel production, and a cadmium factor. PMF found several additional factors. Comparison between source contributions for the similar factors shows reasonable agreement between the two models. The sulfate factor shows the highest contribution to local PM{sub 2.5} with an annual average contribution of approximately 28% (from PMF). The nitrate, crustal material, and primary OC and EC factors also show significant contributions on the order of 10-14%. The sulfate factor is affected by photochemistry and therefore shows maximum values in summer.« less

Unmixing the Materials and Mechanics Contributions in Non-resolved Object Signatures

DTIC Science & Technology

2008-09-01

abundances from hyperspectral or multi-spectral time - resolved signatures. A Fourier analysis of temporal variation of material abundance provides...factorization technique to extract the temporal variation of material abundances from hyperspectral or multi-spectral time - resolved signatures. A Fourier...approximately one hundred wavelengths in the visible spectrum. The frame rate for the instrument was not large enough to collect time resolved data. However

Evaluation of Shielding Performance for Newly Developed Composite Materials

NASA Astrophysics Data System (ADS)

Evans, Beren Richard

This work details an investigation into the contributing factors behind the success of newly developed composite neutron shield materials. Monte Carlo simulation methods were utilized to assess the neutron shielding capabilities and secondary radiation production characteristics of aluminum boron carbide, tungsten boron carbide, bismuth borosilicate glass, and Metathene within various neutron energy spectra. Shielding performance and secondary radiation data suggested that tungsten boron carbide was the most effective composite material. An analysis of the macroscopic cross-section contributions from constituent materials and interaction mechanisms was then performed in an attempt to determine the reasons for tungsten boron carbide's success over the other investigated materials. This analysis determined that there was a positive correlation between a non-elastic interaction contribution towards a material's total cross-section and shielding performance within the thermal and epi-thermal energy regimes. This finding was assumed to be a result of the boron-10 absorption reaction. The analysis also determined that within the faster energy regions, materials featuring higher non-elastic interaction contributions were comparable to those exhibiting primarily elastic scattering via low Z elements. This allowed for the conclusion that composite shield success within higher energy neutron spectra does not necessitate the use elastic scattering via low Z elements. These findings suggest that the inclusion of materials featuring high thermal absorption properties is more critical to composite neutron shield performance than the presence of constituent materials more inclined to maximize elastic scattering energy loss.

Hypermedia Reading Materials: Undergraduate Perceptions and Features Affecting Their Reading Comprehension

ERIC Educational Resources Information Center

Hamdan, Nurul Adila; Mohamad, Maslawati; Shaharuddin, Shahizan

2017-01-01

Due to the potential of the Internet and blended learning environment, students, especially L2 learners, are often required to read references available online. A study was conducted to identify the perceptions of L2 learners comprising TESL undergraduates towards TESL-related hypermedia reading materials and the factors contributing to their…

Report of the NASA Ad Hoc Committee on failure of high strength structural materials

NASA Technical Reports Server (NTRS)

Brown, W. F., Jr. (Editor)

1972-01-01

An analysis of structural failures that have occurred in NASA programs was conducted. Reports of 231 examples of structural failure were reviewed. Attempts were made to identify those factors which contributed to the failures, and recommendations were formulated for actions which would minimize their effects on future NASA programs. Two classes of factors were identified: (1) those associated with deficiencies in existing materials and structures technology and (2) those attributable to inadequate documentation or communication of that technology.

Glass formability in medium-sized molecular systems/pharmaceuticals. I. Thermodynamics vs. kinetics.

PubMed

Tu, Wenkang; Li, Xiangqian; Chen, Zeming; Liu, Ying Dan; Labardi, Massimiliano; Capaccioli, Simone; Paluch, M; Wang, Li-Min

2016-05-07

Scrutinizing critical thermodynamic and kinetic factors for glass formation and the glass stability of materials would benefit the screening of the glass formers for the industry of glassy materials. The present work aims at elucidating the factors that contribute to the glass formation by investigating medium-sized molecules of pharmaceuticals. Glass transition related thermodynamics and kinetics are performed on the pharmaceuticals using calorimetric, dielectric, and viscosity measurements. The characteristic thermodynamic and kinetic parameters of glass transition are found to reproduce the relations established for small-molecule glass formers. The systematic comparison of the thermodynamic and kinetic contributions to glass formation reveals that the melting-point viscosity is the crucial quantity for the glass formation. Of more interest is the finding of a rough correlation between the melting-point viscosity and the entropy of fusion normalized by the number of beads of the pharmaceuticals, suggesting the thermodynamics can partly manifest its contribution to glass formation via kinetics.

Glass formability in medium-sized molecular systems/pharmaceuticals. I. Thermodynamics vs. kinetics

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

Tu, Wenkang; Li, Xiangqian; Chen, Zeming

Scrutinizing critical thermodynamic and kinetic factors for glass formation and the glass stability of materials would benefit the screening of the glass formers for the industry of glassy materials. The present work aims at elucidating the factors that contribute to the glass formation by investigating medium-sized molecules of pharmaceuticals. Glass transition related thermodynamics and kinetics are performed on the pharmaceuticals using calorimetric, dielectric, and viscosity measurements. The characteristic thermodynamic and kinetic parameters of glass transition are found to reproduce the relations established for small-molecule glass formers. The systematic comparison of the thermodynamic and kinetic contributions to glass formation reveals thatmore » the melting-point viscosity is the crucial quantity for the glass formation. Of more interest is the finding of a rough correlation between the melting-point viscosity and the entropy of fusion normalized by the number of beads of the pharmaceuticals, suggesting the thermodynamics can partly manifest its contribution to glass formation via kinetics.« less

20 CFR 404.352 - When does my entitlement to child's benefits begin and end?

Code of Federal Regulations, 2014 CFR

2014-04-01

... entitled to disability benefits based on a finding that drug addiction or alcoholism was a contributing... disability is based on a finding that drug addiction or alcoholism was a contributing factor material to the... otherwise disabled without regard to drug addiction or alcoholism (see § 404.470(c)). (2) If you have...

20 CFR 404.352 - When does my entitlement to child's benefits begin and end?

Code of Federal Regulations, 2013 CFR

2013-04-01

... entitled to disability benefits based on a finding that drug addiction or alcoholism was a contributing... disability is based on a finding that drug addiction or alcoholism was a contributing factor material to the... otherwise disabled without regard to drug addiction or alcoholism (see § 404.470(c)). (2) If you have...

20 CFR 404.352 - When does my entitlement to child's benefits begin and end?

Code of Federal Regulations, 2011 CFR

2011-04-01

... entitled to disability benefits based on a finding that drug addiction or alcoholism was a contributing... disability is based on a finding that drug addiction or alcoholism was a contributing factor material to the... otherwise disabled without regard to drug addiction or alcoholism (see § 404.470(c)). (2) If you have...

20 CFR 404.352 - When does my entitlement to child's benefits begin and end?

Code of Federal Regulations, 2012 CFR

2012-04-01

... entitled to disability benefits based on a finding that drug addiction or alcoholism was a contributing... disability is based on a finding that drug addiction or alcoholism was a contributing factor material to the... otherwise disabled without regard to drug addiction or alcoholism (see § 404.470(c)). (2) If you have...

Do environmental effects on human emotions cause cardiovascular disorders?

PubMed

Rosenman, R H

1997-01-01

Environmental influences on human health include the effects of toxic materials and adverse ecological factors. Natural milieu stressors also affect emotions that may adversely affect cardiovascular function and precipitate or otherwise contribute to complications of cardiovascular diseases. However, although variously hypothesized, there is inadequate evidence that they directly contribute to the pathogenesis of sustained hypertension or coronary atherosclerosis.

3D tensor-based blind multispectral image decomposition for tumor demarcation

NASA Astrophysics Data System (ADS)

Kopriva, Ivica; Peršin, Antun

2010-03-01

Blind decomposition of multi-spectral fluorescent image for tumor demarcation is formulated exploiting tensorial structure of the image. First contribution of the paper is identification of the matrix of spectral responses and 3D tensor of spatial distributions of the materials present in the image from Tucker3 or PARAFAC models of 3D image tensor. Second contribution of the paper is clustering based estimation of the number of the materials present in the image as well as matrix of their spectral profiles. 3D tensor of the spatial distributions of the materials is recovered through 3-mode multiplication of the multi-spectral image tensor and inverse of the matrix of spectral profiles. Tensor representation of the multi-spectral image preserves its local spatial structure that is lost, due to vectorization process, when matrix factorization-based decomposition methods (such as non-negative matrix factorization and independent component analysis) are used. Superior performance of the tensor-based image decomposition over matrix factorization-based decompositions is demonstrated on experimental red-green-blue (RGB) image with known ground truth as well as on RGB fluorescent images of the skin tumor (basal cell carcinoma).

Satisfied and Dissatisfied South Africans: Results from the General Household Survey in International Comparison

ERIC Educational Resources Information Center

Moller, Valerie

2007-01-01

Who are the satisfied South Africans 10 years into democracy? How do material factors contribute to their life satisfaction? These are the questions addressed in this paper. Earlier South African research has consistently found a close positive relationship between life satisfaction and material standards of living in the apartheid and…

Factors Affecting the Use of an E-Learning Portal at University

ERIC Educational Resources Information Center

Cegarra-Navarro, Juan-Gabriel; Rodriguez, Francisco Javier Canovas

2012-01-01

Electronic learning (e-learning) portals can be defined as websites that store and present materials for online learning, training, performance assessment, and certification. Few, if any, studies have investigated the factors that might contribute to the integration or implementation of e-learning portals in universities. With the development of…

Characterisation of soft magnetic materials by measurement: Evaluation of uncertainties up to 1.8 T and 9 kHz

NASA Astrophysics Data System (ADS)

Elfgen, S.; Franck, D.; Hameyer, K.

2018-04-01

Magnetic measurements are indispensable for the characterization of soft magnetic material used e.g. in electrical machines. Characteristic values are used as quality control during production and for the parametrization of material models. Uncertainties and errors in the measurements are reflected directly in the parameters of the material models. This can result in over-dimensioning and inaccuracies in simulations for the design of electrical machines. Therefore, existing influencing factors in the characterization of soft magnetic materials are named and their resulting uncertainties contributions studied. The analysis of the resulting uncertainty contributions can serve the operator as additional selection criteria for different measuring sensors. The investigation is performed for measurements within and outside the currently prescribed standard, using a Single sheet tester and its impact on the identification of iron loss parameter is studied.

Amounts, isotopic character and ages of organic and inorganic carbon exported from rivers to ocean margins: Assessment of natural and anthropogenic controls

NASA Astrophysics Data System (ADS)

Bauer, J. E.; Hossler, K.

2012-12-01

Riverine exports of carbon (C) and organic matter (OM) are regulated by a variety of natural and anthropogenic factors. Understanding the relationships between these various factors and C and OM exports can help to constrain global C budgets, as well allow assessment of current and future anthropogenic impacts on both riverine and global C cycles. We quantified the effects of multiple natural and anthropogenic controls on riverine export fluxes and compositions of particulate organic C (POC), dissolved organic C (DOC), and dissolved inorganic C (DIC) for a regional group of eight rivers in the northeastern U.S. For allochthonous and aged C contributions to POC, DOC and DIC exports, we first estimated fractional contributions from six potential sources for POC and DOC (i.e., modern C3 plant material (C3-OC), modern C4 plant material (C4-OC), modern algal material (algal OC), slow-turnover soil OC (slow SOC; turnover time 25 yr), passive-turnover soil OC (passive SOC; turnover time 5,000 yr) and fossil OC and four potential sources for DIC (i.e., modern atmospheric CO2 exchange, carbonate dissolution, POC remineralization and DOC remineralization) using a novel time-varying isotope mixing model. Using these estimated source contributions, we then estimated the allochthonous proportions of (a) the POC and DOC pools to be the C3-OC, C4-OC, slow SOC, passive SOC, and fossil OC contributions; and (b) the DIC pools to be the dissolved carbonates, remineralized allochthonous POC, and remineralized allochthonous DOC contributions. We considered aged C to be anything older than ˜ 60 yr, which included passive SOC and fossil OC for POC and DOC and dissolved carbonates and aged fractions of remineralized POC and DOC for DIC. Potential controls related to hydrogeomorphology and regional climate, soil order, soil texture, bedrock lithology, land use, and additional anthropogenic factors were analyzed collectively, individually, and at scales of both local and regional influence. Factors related either to hydrogeomorphology and climate or to anthropogenic factors exhibited the strongest impacts on riverine C exports and compositions, particularly at broader regional scales. The effect of hydrogeomorphology and climate was primarily one of size, as larger watersheds with greater discharge exported more total C and terrestrial C. Principal anthropogenic factors included impacts of wastewater treatment plants (WWTPs) and river impoundments. The presence of WWTPs as well as anthropogenic use of carbonate-based materials (e.g., limestone) may have substantially increased riverine C exports, particularly fossil C exports, in the study region. The presence of nuclear power plants in the associated watersheds is also discussed because of the potential for anthropogenic 14C inputs and subsequent biasing of aquatic C studies utilizing natural abundance 14C.

Construction cost impacts related to manpower, material, and equipment factors in contractor firms perspective

NASA Astrophysics Data System (ADS)

Husin, Saiful; Abdullah, Riza, Medyan; Afifuddin, Mochammad

2017-11-01

Risk can be defined as consequences which possible happened inscrutably. Although an activity has planned as good as possible, but it keep contains uncertainty. Implementation of construction project was encountering various risk impacts from a number of risk factors. This study was intended to analyze the impacts of construction cost to for contractor firms as construction project executor related to the factors of manpower, material and equipment. The study was using data obtained from questionnaires distributed to 15 large qualification contractor firms. The period of study classified into conflict period (2000-2004), post tsunami disaster rehabilitation and reconstruction period (2005-2009), and post rehabilitation and reconstruction period (2010-present). The statistical analysis of severity index and variance used to analyze the data. The three risk factors reviewed generally affected the cost in a medium impact. The high impact occurred in minor variables, which are `increase in material prices', `theft of materials', and `the fuel scarcity'. In overall, the three risk factors and the observed period contributed significant impact on construction costs.

DetOx: a program for determining anomalous scattering factors of mixed-oxidation-state species.

PubMed

Sutton, Karim J; Barnett, Sarah A; Christensen, Kirsten E; Nowell, Harriott; Thompson, Amber L; Allan, David R; Cooper, Richard I

2013-01-01

Overlapping absorption edges will occur when an element is present in multiple oxidation states within a material. DetOx is a program for partitioning overlapping X-ray absorption spectra into contributions from individual atomic species and computing the dependence of the anomalous scattering factors on X-ray energy. It is demonstrated how these results can be used in combination with X-ray diffraction data to determine the oxidation state of ions at specific sites in a mixed-valance material, GaCl(2).

20 CFR 416.1123 - How we count unearned income.

Code of Federal Regulations, 2014 CFR

2014-04-01

... period for which you did not receive SSI. (2) Social security disability benefits where drug addiction or... benefits to disabled recipients whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1123 - How we count unearned income.

Code of Federal Regulations, 2013 CFR

2013-04-01

... period for which you did not receive SSI. (2) Social security disability benefits where drug addiction or... benefits to disabled recipients whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1123 - How we count unearned income.

Code of Federal Regulations, 2011 CFR

2011-04-01

... period for which you did not receive SSI. (2) Social security disability benefits where drug addiction or... benefits to disabled recipients whose drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1123 - How we count unearned income.

Code of Federal Regulations, 2012 CFR

2012-04-01

... period for which you did not receive SSI. (2) Social security disability benefits where drug addiction or... benefits to disabled recipients whose drug addiction or alcoholism is a contributing factor material to the...

Use of World Wide Web Server and Browser Software To Support a First-Year Medical Physiology Course.

ERIC Educational Resources Information Center

Davis, Michael J.; And Others

1997-01-01

Describes the use of a World Wide Web server to support a team-taught physiology course for first-year medical students. The students' evaluations indicate that computer use in class made lecture material more interesting, while the online documents helped reinforce lecture materials and textbooks. Lists factors which contribute to the…

Prevalence and Potential Factors Associated with Overweight and Obesity Status in Adults with Intellectual Developmental Disorders

ERIC Educational Resources Information Center

Ranjan, Sobhana; Nasser, Jennifer A.; Fisher, Kathleen

2018-01-01

Background: The prevalence of being overweight and obese is increasing not just in the general population but also in individuals with intellectual disability (ID). Therefore, a need to identify factors contributing to overweight/obesity arises as this population is escalating. Materials and Methods: This narrative review article summarizes…

A Review: Characteristics of Noise Absorption Material

NASA Astrophysics Data System (ADS)

Amares, S.; Sujatmika, E.; Hong, T. W.; Durairaj, R.; Hamid, H. S. H. B.

2017-10-01

Noise is always treated as a nuisance to human and even noise pollution appears in the environmental causing discomfort. This also concerns the engineering design that tends to cultivate this noise propagation. Solution such as using material to absorb the sound have been widely used. The fundamental of the sound absorbing propagation, sound absorbing characteristics and its factors are minimally debated. Furthermore, the method in order to pertain sound absorbing related to the sound absorption coefficient is also limited, as many studies only contributes in result basis and very little in literature aspect. This paper revolves in providing better insight on the importance of sound absorption and the materials factors in obtaining the sound absorption coefficient.

Evaluation of concrete pavements with materials-related distress : appendix G.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : final report.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors : contributing to pavement distress observed in the field were determined, including expansive : alkali-silica reactivity and freeze-thaw deterioration related to poor ...

Evaluation of concrete pavements with materials-related distress : appendix F.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix E.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix D.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix B.

DOT National Transportation Integrated Search

2010-02-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix C.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Engineering long term clinical success of advanced ceramic prostheses.

PubMed

Rekow, Dianne; Thompson, Van P

2007-01-01

Biocompatability and, in some applications, esthetics make all-ceramic prostheses compelling choices but despite significant improvements in materials properties and toughening mechanisms, these still have significant failure rates. Factors that contribute to the degradation in strength and survival include material selection and prosthesis design which set the upper limit for performance. However, fabrication operations introduce damage that can be exacerbated by environmental conditions and clinical function. Using all-ceramic dental crowns as an example, experimentally derived models provide insight into the relationships between materials properties and initial critical loads to failure. Analysis of fabrication operations suggests strategies to minimize damage. Environmental conditions can create viscoplastic flow of supporting components which can contribute additional stress within the prosthesis. Fatigue is a particularly challenging problem, not only providing the energy to propagate existing damage but, when combined with the wet environment, can create new damage modes. While much is known, the influence of these new damage modes has not been completely elucidated. The role of complex prosthesis geometry and its interaction with other factors on damage initiation and propagation has yet to be well characterized.

Proton transport in functionalised additives for PEM fuel cells: contributions from atomistic simulations.

PubMed

Tölle, Pia; Köhler, Christof; Marschall, Roland; Sharifi, Monir; Wark, Michael; Frauenheim, Thomas

2012-08-07

The conventional polymer electrolyte membrane (PEM) materials for fuel cell applications strongly rely on temperature and pressure conditions for optimal performance. In order to expand the range of operating conditions of these conventional PEM materials, mesoporous functionalised SiO(2) additives are developed. It has been demonstrated that these additives themselves achieve proton conductivities approaching those of conventional materials. However, the proton conduction mechanisms and especially factors influencing charge carrier mobility under different hydration conditions are not well known and difficult to separate from concentration effects in experiments. This tutorial review highlights contributions of atomistic computer simulations to the basic understanding and eventual design of these materials. Some basic introduction to the theoretical and computational framework is provided to introduce the reader to the field, the techniques are in principle applicable to a wide range of other situations as well. Simulation results are directly compared to experimental data as far as possible.

20 CFR 416.610 - When payment will be made to a representative payee.

Code of Federal Regulations, 2014 CFR

2014-04-01

... his or her benefit payments; or (3) Eligible for benefits solely on the basis of disability and drug addiction or alcoholism is a contributing factor material to the determination of disability. (b) Generally...

20 CFR 416.610 - When payment will be made to a representative payee.

Code of Federal Regulations, 2012 CFR

2012-04-01

... his or her benefit payments; or (3) Eligible for benefits solely on the basis of disability and drug addiction or alcoholism is a contributing factor material to the determination of disability. (b) Generally...

Evaluation of concrete pavements with materials-related distress : appendix A, part 1.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix A, part 3.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Evaluation of concrete pavements with materials-related distress : appendix A, part 2.

DOT National Transportation Integrated Search

2010-03-02

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entr...

Machinability Study on Milling Kenaf Fiber Reinforced Plastic Composite Materials using Design of Experiments

NASA Astrophysics Data System (ADS)

Azmi, H.; Haron, C. H. C.; Ghani, J. A.; Suhaily, M.; Yuzairi, A. R.

2018-04-01

The surface roughness (Ra) and delamination factor (Fd) of a milled kenaf reinforced plastic composite materials are depending on the milling parameters (spindle speed, feed rate and depth of cut). Therefore, a study was carried out to investigate the relationship between the milling parameters and their effects on a kenaf reinforced plastic composite materials. The composite panels were fabricated using vacuum assisted resin transfer moulding (VARTM) method. A full factorial design of experiments was use as an initial step to screen the significance of the parameters on the defects using Analysis of Variance (ANOVA). If the curvature of the collected data shows significant, Response Surface Methodology (RSM) is then applied for obtaining a quadratic modelling equation that has more reliable in expressing the optimization. Thus, the objective of this research is obtaining an optimum setting of milling parameters and modelling equations to minimize the surface roughness (Ra) and delamination factor (Fd) of milled kenaf reinforced plastic composite materials. The spindle speed and feed rate contributed the most in affecting the surface roughness and the delamination factor of the kenaf composite materials.

Bridging the gap between preventive and restorative dentistry: identification of caries risk factors and strategies for minimizing risk.

PubMed

Maragliano-Muniz, Pamela

2013-10-01

Following the introduction of CAMBRA (Caries Management by Risk Assessment) in 2007, a number of recommendations for office protocols were introduced, and many companies have formulated products and procedures for implementing CAMBRA. As a result, the implementation of a caries management program can be confounding and overwhelming to a dental practitioner. Understanding risk factors as they contribute to the caries process can help mitigate confusion and guide the practitioner when selecting materials for their practice. Ultimately, knowing how the risk factors play a role in the progression of dental caries will lead to appropriate risk management and product recommendations. The purpose of this article is to discuss the contribution of risk factors to the caries process and to introduce strategies that restorative dentists can utilize to minimize caries risk.

Hot/Wet Open Hole Compression Strength of Carbon/Epoxy Laminates for Launch Vehicle Applications

NASA Technical Reports Server (NTRS)

Nettles, Alan T.

2009-01-01

This Technical Memorandum examines the effects of heat and absorbed moisture on the open hole compression strength of carbon/epoxy laminates with the material and layup intended for the Ares I composite interstage. The knockdown due to temperature, amount of moisture absorbed, and the interaction between these two are examined. Results show that temperature is much more critical than the amount of moisture absorbed. The environmental knockdown factor was found to be low for this material and layup and thus obtaining a statistically significant number for this value needs to be weighed against a program s cost and schedule since basis values, damage tolerance, and safety factors all contribute much more to the overall knockdown factor.

Regional mortality by socioeconomic factors in Slovakia: a comparison of 15 years of changes.

PubMed

Rosicova, Katarina; Bosakova, Lucia; Madarasova Geckova, Andrea; Rosic, Martin; Andrejkovic, Marek; Žežula, Ivan; Groothoff, Johan W; van Dijk, Jitse P

2016-07-19

Like most Central European countries Slovakia has experienced a period of socioeconomic changes and at the same time a decline in the mortality rate. Therefore, the aim is to study socioeconomic factors that changed over time and simultaneously contributed to regional differences in mortality. The associations between selected socioeconomic indicators and the standardised mortality rate in the population aged 20-64 years in the districts of the Slovak Republic in the periods 1997-1998 and 2012-2013 were analysed using linear regression models. A higher proportion of inhabitants in material need, and among males also lower income, significantly contributed to higher standardised mortality in both periods. The unemployment rate did not contribute to this prediction. Between the two periods no significant changes in regional mortality differences by the selected socioeconomic factors were found. Despite the fact that economic growth combined with investments of European structural funds contributed to the improvement of the socioeconomic situation in many districts of Slovakia, there are still districts which remain "poor" and which maintain regional mortality differences.

Key factors of successful JIT integration with IBS - An overview

NASA Astrophysics Data System (ADS)

Asri, Mohammad Azwanie Naim Mohammad; Nawi, Mohd Nasrun Mohd; Nadarajan, Santhirasegaran

2016-08-01

The Just-In-Time (JIT) philosophy has been used for many decades to increase productivity through waste elimination process. The purpose of this paper is to contribute to the knowledge by addressing the transportation and material delivery activities in Industrialized Building System (IBS) and integrating JIT to improve the performance of those activities. The literature review has been conducted through relevant database. It was found that there is a need for more holistic approach to be adopted to integrate JIT in IBS project. This paper discusses the key success factors for effective integration between JIT and IBS in the context of transportation and material delivery activities.

Deformation partitioning provides insight into elastic, plastic, and viscous contributions to bone material behavior.

PubMed

Ferguson, V L

2009-08-01

The relative contributions of elastic, plastic, and viscous material behavior are poorly described by the separate extraction and analysis of the plane strain modulus, E('), the contact hardness, H(c) (a hybrid parameter encompassing both elastic and plastic behavior), and various viscoelastic material constants. A multiple element mechanical model enables the partitioning of a single indentation response into its fundamental elastic, plastic, and viscous deformation components. The objective of this study was to apply deformation partitioning to explore the role of hydration, tissue type, and degree of mineralization in bone and calcified cartilage. Wet, ethanol-dehydrated, and PMMA-embedded equine cortical bone samples and PMMA-embedded human femoral head tissues were analyzed for contributions of elastic, plastic and viscous deformation to the overall nanoindentation response at each site. While the alteration of hydration state had little effect on any measure of deformation, unembedded tissues demonstrated significantly greater measures of resistance to plastic deformation than PMMA-embedded tissues. The PMMA appeared to mechanically stabilize the tissues and prevent extensive permanent deformation within the bone material. Increasing mineral volume fraction correlated with positive changes in E('), H(c), and resistance to plastic deformation, H; however, the partitioned deformation components were generally unaffected by mineralization. The contribution of viscous deformation was minimal and may only play a significant role in poorly mineralized tissues. Deformation partitioning enables a detailed interpretation of the elastic, plastic, and viscous contributions to the nanomechanical behavior of mineralized tissues that is not possible when examining modulus and contact hardness alone. Varying experimental or biological factors, such as hydration or mineralization level, enables the understanding of potential mechanisms for specific mechanical behavior patterns that would otherwise be hidden within a more complex set of material property parameters.

Renal stone risk assessment during Space Shuttle flights

NASA Technical Reports Server (NTRS)

Whitson, P. A.; Pietrzyk, R. A.; Pak, C. Y.

1997-01-01

PURPOSE: The metabolic and environmental factors influencing renal stone formation before, during, and after Space Shuttle flights were assessed. We established the contributing roles of dietary factors in relationship to the urinary risk factors associated with renal stone formation. MATERIALS AND METHODS: 24-hr. urine samples were collected prior to, during space flight, and following landing. Urinary and dietary factors associated with renal stone formation were analyzed and the relative urinary supersaturation of calcium oxalate, calcium phosphate (brushite), sodium urate, struvite and uric acid were calculated. RESULTS: Urinary composition changed during flight to favor the crystallization of calcium-forming salts. Factors that contributed to increased potential for stone formation during space flight were significant reductions in urinary pH and increases in urinary calcium. Urinary output and citrate, a potent inhibitor of calcium-containing stones, were slightly reduced during space flight. Dietary intakes were significantly reduced for a number of variables, including fluid, energy, protein, potassium, phosphorus and magnesium. CONCLUSIONS: This is the first in-flight characterization of the renal stone forming potential in astronauts. With the examination of urinary components and nutritional factors, it was possible to determine the factors that contributed to increased risk or protected from risk. In spite of the protective components, the negative contributions to renal stone risk predominated and resulted in a urinary environment that favored the supersaturation of stone-forming salts. Dietary and pharmacologic therapies need to be assessed to minimize the potential for renal stone formation in astronauts during/after space flight.

Thermal comfort of seats as visualized by infrared thermography.

PubMed

Sales, Rosemary Bom Conselho; Pereira, Romeu Rodrigues; Aguilar, Maria Teresa Paulino; Cardoso, Antônio Valadão

2017-07-01

Published studies that deal with the question of how the temperature of chair seats influences human activities are few, but the studies considering such a factor, a function of the type of material, could contribute to improvements in the design of chairs. This study evaluates seat temperatures of 8 types of chairs made of different materials. The parts of the furniture that people come into contact with, and the thermal response of the material to heating and cooling have been evaluated. Infrared thermography was used for this, as it is a non-contact technique that does not present any type of risk in the measurement of temperatures. Seats made of synthetic leather (leatherette), wood and polyester fabric were found to have the highest temperatures, and the plywood seat showed the lowest. The study has also revealed that thermography can contribute to studies of thermal comfort of chair seats in addition to determining the most suitable material. Copyright © 2017 Elsevier Ltd. All rights reserved.

The contribution of molecular genetics to the understanding and management of cancer: potential future applications and implications for nurses.

PubMed

Bradley, A N

1999-06-01

Cancer is an immense medical problem and as a cause of mortality it is second only to cardiovascular disease. Much of the current understanding of cancer is owed to epidemiologists who have discovered a number of causative factors implicated in its development. These causative factors can be divided into genetic, chemical, physical, viral, radiation, immune and hormonal factors. Further advances in understanding have been made over the past decade from contributions made by the field of molecular biology. From investigation and examination of the molecular processes involved in the development of cancer it is becoming increasingly clear that changes in the genetic material of the cell nuclei are the final common pathway to cancer, whatever the initial aetiology. This article will attempt to elucidate the contribution of molecular genetics to the understanding of the likely mechanisms of carcinogenesis, the management of cancer, potential future applications and directions and the implications for nurses arising from this relatively new and evolving field of knowledge.

Statistical analysis of the factors that influenced the mechanical properties improvement of cassava starch films

NASA Astrophysics Data System (ADS)

Monteiro, Mayra; Oliveira, Victor; Santos, Francisco; Barros Neto, Eduardo; Silva, Karyn; Silva, Rayane; Henrique, João; Chibério, Abimaelle

2017-08-01

In order to obtain cassava starch films with improved mechanical properties in relation to the synthetic polymer in the packaging production, a complete factorial design 23 was carried out in order to investigate which factor significantly influences the tensile strength of the biofilm. The factors to be investigated were cassava starch, glycerol and modified clay contents. Modified bentonite clay was used as a filling material of the biofilm. Glycerol was the plasticizer used to thermoplastify cassava starch. The factorial analysis suggested a regression model capable of predicting the optimal mechanical property of the cassava starch film from the maximization of the tensile strength. The reliability of the regression model was tested by the correlation established with the experimental data through the following statistical analyse: Pareto graph. The modified clay was the factor of greater statistical significance on the observed response variable, being the factor that contributed most to the improvement of the mechanical property of the starch film. The factorial experiments showed that the interaction of glycerol with both modified clay and cassava starch was significant for the reduction of biofilm ductility. Modified clay and cassava starch contributed to the maximization of biofilm ductility, while glycerol contributed to the minimization.

Materials testing of the IUS techroll seal material

NASA Technical Reports Server (NTRS)

Nichols, R. L.; Hall, W. B.

1984-01-01

As a part of the investigation of the control system failure Inertial Upper Stage on IUS-1 flight to position a Tracking and Data Relay Satellite (TDRS) in geosynchronous orbit, the materials utilized in the techroll seal are evaluated for possible failure models. Studies undertaken included effect of temperature on the strength of the system, effect of fatigue on the strength of the system, thermogravimetric analysis, thermomechanical analysis, differential scanning calorimeter analysis, dynamic mechanical analysis, and peel test. The most likely failure mode is excessive temperature in the seal. In addition, the seal material is susceptible to fatigue damage which could be a contributing factor.

Apparatus and method for quantitative assay of samples of transuranic waste contained in barrels in the presence of matrix material

DOEpatents

Caldwell, J.T.; Herrera, G.C.; Hastings, R.D.; Shunk, E.R.; Kunz, W.E.

1987-08-28

Apparatus and method for performing corrections for matrix material effects on the neutron measurements generated from analysis of transuranic waste drums using the differential-dieaway technique. By measuring the absorption index and the moderator index for a particular drum, correction factors can be determined for the effects of matrix materials on the ''observed'' quantity of fissile and fertile material present therein in order to determine the actual assays thereof. A barrel flux monitor is introduced into the measurement chamber to accomplish these measurements as a new contribution to the differential-dieaway technology. 9 figs.

The Built Environment Is a Microbial Wasteland

PubMed Central

2016-01-01

ABSTRACT Humanity’s transition from the outdoor environment to the built environment (BE) has reduced our exposure to microbial diversity. The relative importance of factors that contribute to the composition of human-dominated BE microbial communities remains largely unknown. In their article in this issue, Chase and colleagues (J. Chase, J. Fouquier, M. Zare, D. L. Sonderegger, R. Knight, S. T. Kelley, J. Siegel, and J. G. Caporaso, mSystems 1(2):e00022-16, 2016, http://dx.doi.org/10.1128/mSystems.00022-16) present an office building study in which they controlled for environmental factors, geography, surface material, sampling location, and human interaction type. They found that surface location and geography were the strongest factors contributing to microbial community structure, while surface material had little effect. Even in the absence of direct human interaction, BE surfaces were composed of 25 to 30% human skin-associated taxa. The authors demonstrate how technical variation across sequencing runs is a major issue, especially in BE work, where the biomass is often low and the potential for PCR contaminants is high. Overall, the authors conclude that BE surfaces are desert-like environments where microbes passively accumulate. PMID:27832216

Factors Influencing Achievement in Junior School Certificate Examination (JSCE) in Home Economics in Nigeria

ERIC Educational Resources Information Center

Badmus, Medinat M. O.

2007-01-01

This study was undertaken to assess the contributions of teachers' knowledge of Curriculum Characteristics, value internalization and commitment, perception of adequacy of facilities, equipment and materials, and degree of performance of implementation roles/behaviours to achievements in Junior Secondary Certificate Examination in Home Economics.…

Factors Contributing to Stress in Parents of Individuals with Autistic Spectrum Disorders

ERIC Educational Resources Information Center

Tehee, Erin; Honan, Rita; Hevey, David

2009-01-01

Background: The study explores the experiences of parents of individuals with autistic spectrum disorders (ASDs), and examines the influences of parent gender and child age on perceived stress, stress and coping, child-rearing involvement, support and information/education accessed. Methods and Materials: Questionnaires assessed general perceived…

The Last Book: The Delivery of Future Content.

ERIC Educational Resources Information Center

Lim, Edward

This paper discusses the future of the printed book. The first section considers factors contributing to predictions of its eventual demise and replacement by electronic versions, the increasing volume of digitized material, superior characteristics of digital publications, and the development of technologies that will allow the e-book to become…

75 FR 58348 - Revision of the Shoshone National Forest Land and Resource Management Plan

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... process: 1. Comprehensive Evaluation Report (CER) (April 2009)--Much of the background material in this report will be carried forward in the Analysis of the Management Situation or draft EIS. The CER..., and ecological conditions and trends that contribute to sustainability. The CER identifies factors...

X-band noise temperature effects of rain on DSN antenna feedhorns

NASA Technical Reports Server (NTRS)

Slobin, S. D.; Franco, M. M.; Clauss, R. C.

1982-01-01

Simulated rain tests were carried out to determine the noise temperature contribution of liquid water adhering to the aperture cover material on both a standard DSN X-band feedhorn and on an S/X-band common aperture feedhorn. It was found that for the particular common aperture feedhorn tested, system noise temperature increases were much greater when the plastic horn cover material was old and weathered than when it was new. The age and condition of the aperture cover material is believed to be a major factor in the amount of degradation experienced by a telecommunications system during rain events.

Important roles of enthalpic and entropic contributions to CO2 capture from simulated flue gas and ambient air using mesoporous silica grafted amines.

PubMed

Alkhabbaz, Mustafa A; Bollini, Praveen; Foo, Guo Shiou; Sievers, Carsten; Jones, Christopher W

2014-09-24

The measurement of isosteric heats of adsorption of silica supported amine materials in the low pressure range (0-0.1 bar) is critical for understanding the interactions between CO2 and amine sites at low coverage and hence to the development of efficient amine adsorbents for CO2 capture from flue gas and ambient air. Heats of adsorption for an array of silica-supported amine materials are experimentally measured at low coverage using a Calvet calorimeter equipped with a customized dosing manifold. In a series of 3-aminopropyl-functionalized silica materials, higher amine densities resulted in higher isosteric heats of adsorption, clearly showing that the density/proximity of amine sites can influence the amine efficiency of adsorbents. In a series of materials with fixed amine loading but different amine types, strongly basic primary and secondary amine materials are shown to have essentially identical heats of adsorption near 90 kJ/mol. However, the adsorption uptakes vary substantially as a function of CO2 partial pressure for different primary and secondary amines, demonstrating that entropic contributions to adsorption may play a key role in adsorption at secondary amine sites, making adsorption at these sites less efficient at the low coverages that are important to the direct capture of CO2 from ambient air. Thus, while primary amines are confirmed to be the most effective amine types for CO2 capture from ambient air, this is not due to enhanced enthalpic contributions associated with primary amines over secondary amines, but may be due to unfavorable entropic factors associated with organization of the second alkyl chain on the secondary amine during CO2 adsorption. Given this hypothesis, favorable entropic factors may be the main reason primary amine based adsorbents are more effective under air capture conditions.

A Protocol for Lifetime Energy and Environmental Impact Assessment of Building Insulation Materials

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

Shrestha, Som S; Biswas, Kaushik; Desjarlais, Andre Omer

This article describes a proposed protocol that is intended to provide a comprehensive list of factors to be considered in evaluating the direct and indirect environmental impacts of building insulation materials, as well as detailed descriptions of standardized calculation methodologies to determine those impacts. The energy and environmental impacts of insulation materials can generally be divided into two categories: (1) direct impact due to the embodied energy of the insulation materials and other factors, and (2) indirect or environmental impacts avoided as a result of reduced building energy use due to addition of insulation. Standards and product category rules existmore » that provide guidelines about the life cycle assessment (LCA) of materials, including building insulation products. However, critical reviews have suggested that these standards fail to provide complete guidance to LCA studies and suffer from ambiguities regarding the determination of the environmental impacts of building insulation and other products. The focus of the assessment protocol described here is to identify all factors that contribute to the total energy and environmental impacts of different insulation products and, more importantly, provide standardized determination methods that will allow comparison of different insulation material types. Further, the intent is not to replace current LCA standards but to provide a well-defined, easy-to-use comparison method for insulation materials using existing LCA guidelines.« less

Roofing Materials Assessment: Investigation of Five Metals in Runoff from Roofing Materials.

PubMed

Winters, Nancy; Granuke, Kyle; McCall, Melissa

2015-09-01

To assess the contribution of five toxic metals from new roofing materials to stormwater, runoff was collected from 14 types of roofing materials and controls during 20 rain events and analyzed for metals. Many of the new roofing materials evaluated did not show elevated metals concentrations in the runoff. Runoff from several other roofing materials was significantly higher than the controls for arsenic, copper, and zinc. Notably, treated wood shakes released arsenic and copper, copper roofing released copper, PVC roofing released arsenic, and Zincalume® and EPDM roofing released zinc. For the runoff from some of the roofing materials, metals concentrations decreased significantly over an approximately one-year period of aging. Metals concentrations in runoff were demonstrated to depend on a number of factors, such as roofing materials, age of the materials, and climatic conditions. Thus, application of runoff concentrations from roofing materials to estimate basin-wide releases should be undertaken cautiously.

Source apportionment of heavy metals and ionic contaminants in rainwater tanks in a subtropical urban area in Australia.

PubMed

Huston, R; Chan, Y C; Chapman, H; Gardner, T; Shaw, G

2012-03-15

Due to prolonged droughts in recent years, the use of rainwater tanks in urban areas has increased in Australia. In order to apportion sources of contribution to heavy metal and ionic contaminants in rainwater tanks in Brisbane, a subtropical urban area in Australia, monthly tank water samples (24 sites, 31 tanks) and concurrent bulk deposition samples (18 sites) were collected during mainly April 2007-March 2008. The samples were analysed for acid-soluble metals, soluble anions, total inorganic carbon and total organic carbon, and characteristics such as total solid and pH. The Positive Matrix Factorisation model, EPA PMF 3.0, was used to apportion sources of contribution to the contaminants. Four source factors were identified for the bulk deposition samples, including 'crustal matter/sea salt', 'car exhausts/road side dust', 'industrial dust' and 'aged sea salt/secondary aerosols'. For the tank water samples, apart from these atmospheric deposition related factors which contributed in total to 65% of the total contaminant concentration on average, another six rainwater collection system related factors were identified, including 'plumbing', 'building material', 'galvanizing', 'roofing', 'steel' and 'lead flashing/paint' (contributing in total to 35% of the total concentration on average). The Australian Drinking Water Guideline for lead was exceeded in 15% of the tank water samples. The collection system related factors, in particular the 'lead flashing/paint' factor, contributed to 79% of the lead in the tank water samples on average. The concentration of lead in tank water was found to vary with various environmental and collection system factors, in particular the presence of lead flashing on the roof. The results also indicated the important role of sludge dynamics inside the tank on the quality of tank water. Copyright © 2011 Elsevier Ltd. All rights reserved.

One step sintering of homogenized bauxite raw material and kinetic study

NASA Astrophysics Data System (ADS)

Gao, Chang-he; Jiang, Peng; Li, Yong; Sun, Jia-lin; Zhang, Jun-jie; Yang, Huan-ying

2016-10-01

A one-step sintering process of bauxite raw material from direct mining was completed, and the kinetics of this process was analyzed thoroughly. The results show that the sintering kinetics of bauxite raw material exhibits the liquid-phase sintering behavior. A small portion of impurities existed in the raw material act as a liquid phase. After X-ray diffraction analyses, scanning electron microscopy observations, and kinetics calculations, sintering temperature and heating duration were determined as the two major factors contributing to the sintering process and densification of bauxite ore. An elevated heating temperature and longer duration favor the densification process. The major obstacle for the densification of bauxite material is attributed to the formation of the enclosed blowhole during liquid-phase sintering.

[Agricultural soil contamination from As and Cd and its responses to landscape heterogeneity at multiple scales in Guangzhou, China].

PubMed

Xu, Hui Qiu; Huang, Yin Hua; Wu, Zhi Feng; Cheng, Jiong; Li, Cheng

2016-10-01

Based on 641 agricultural top soil samples (0-20 cm) and land use map in 2005 of Guangzhou, we used single-factor pollution indices and Pearson/Spearman correlation and partial redundancy analyses and quantified the soil contamination with As and Cd and their relationships with landscape heterogeneity at three grid scales of 2 km×2 km, 5 km×5 km, and 10 km×10 km as well as the determinant landscape heterogeneity factors at a certain grid scale. 5.3% and 7.2% of soil samples were contaminated with As and Cd, respectively. At the three scales, the agricultural soil As and Cd contamination were generally significantly correlated with parent materials' composition, river/road density and landscape patterns of several land use types, indicating the parent materials, sewage irrigation and human activities (e.g., industrial and traffic activities, and the additions of pesticides and fertilizers) were possibly the main input pathways of trace metals. Three subsets of landscape heterogeneity variables (i.e., parent materials, distance-density variables, and landscape patterns) could explain 12.7%-42.9% of the variation of soil contamination with As and Cd, of which the explanatory power increased with the grid scale and the determinant factors varied with scales. Parent materials had higher contribution to the variations of soil contamination at the 2 and 10 km grid scales, while the contributions of landscape patterns and distance-density variables generally increased with the grid scale. Adjusting the distribution of cropland and optimizing the landscape pattern of land use types are important ways to reduce soil contamination at local scales, which urban planners and decision makers should pay more attention to.

Horse manure as feedstock for anaerobic digestion.

PubMed

Hadin, Sa; Eriksson, Ola

2016-10-01

Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. Copyright © 2016. Published by Elsevier Ltd.

Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements

PubMed Central

Hufenbach, Werner; Adam, Frank; Heber, Thomas; Weckend, Nico; Bach, Friedrich-Wilhelm; Hassel, Thomas; Zaremba, David

2011-01-01

Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair. PMID:28824134

Effect of temperature and humidity on formaldehyde emissions in temporary housing units.

PubMed

Parthasarathy, Srinandini; Maddalena, Randy L; Russell, Marion L; Apte, Michael G

2011-06-01

The effect of temperature and humidity on formaldehyde emissions from samples collected from temporary housing units (THUs) was studied. The THUs were supplied by the U.S. Federal Emergency Management Administration (FEMA) to families that lost their homes in Louisiana and Mississippi during the Hurricane Katrina and Rita disasters. On the basis of a previous study, four of the composite wood surface materials that dominated contributions to indoor formaldehyde were selected to analyze the effects of temperature and humidity on the emission factors. Humidity equilibration experiments were carried out on two of the samples to determine how long the samples take to equilibrate with the surrounding environmental conditions. Small chamber experiments were then conducted to measure emission factors for the four surface materials at various temperature and humidity conditions. The samples were analyzed for formaldehyde via high-performance liquid chromatography. The experiments showed that increases in temperature or humidity contributed to an increase in emission factors. A linear regression model was built using the natural log of the percent relative humidity (RH) and inverse of temperature (in K) as independent variables and the natural log of emission factors as the dependent variable. The coefficients for the inverse of temperature and log RH with log emission factor were found to be statistically significant for all of the samples at the 95% confidence level. This study should assist in retrospectively estimating indoor formaldehyde exposure of occupants of THUs.

Consumption of Pornographic Materials among Hong Kong Early Adolescents: A Replication

PubMed Central

Shek, Daniel T. L.; Ma, Cecilia M. S.

2012-01-01

Consumption of pornographic materials was examined in 3,638 secondary 2 students in Hong Kong. Results showed that over 80% of the respondents had never consumed pornographic materials in the past year. Internet pornography was the most common medium that adolescents used when viewing pornographic materials. Males reported a higher level of pornography consumption than did females. Participants who were born in mainland China were more likely to consume pornographic materials than their Hong Kong counterparts. Regardless of the types of pornographic materials, the levels of pornography consumption significantly increased over time. Results also showed that higher levels of positive youth development and better family functioning were concurrently related to a lower level of pornography consumption at secondary 2. The relative contribution of positive youth development and family factors to pornographic material consumption was also explored. PMID:22778698

Consumption of pornographic materials among Hong Kong early adolescents: a replication.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2012-01-01

Consumption of pornographic materials was examined in 3,638 secondary 2 students in Hong Kong. Results showed that over 80% of the respondents had never consumed pornographic materials in the past year. Internet pornography was the most common medium that adolescents used when viewing pornographic materials. Males reported a higher level of pornography consumption than did females. Participants who were born in mainland China were more likely to consume pornographic materials than their Hong Kong counterparts. Regardless of the types of pornographic materials, the levels of pornography consumption significantly increased over time. Results also showed that higher levels of positive youth development and better family functioning were concurrently related to a lower level of pornography consumption at secondary 2. The relative contribution of positive youth development and family factors to pornographic material consumption was also explored.

20 CFR 404.316 - When entitlement to disability benefits begins and ends.

Code of Federal Regulations, 2014 CFR

2014-04-01

... benefits for any months in which you do substantial gainful activity. (e) If drug addiction or alcoholism... addiction or alcoholism is not available, months before March 1995, and months for which your benefit.... (f) If drug addiction or alcoholism is a contributing factor material to the determination of...

20 CFR 416.1331 - Termination of your disability or blindness payments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... due to 12 consecutive suspension months for failure to comply with treatment for drug addiction or alcoholism. If you are disabled and drug addiction or alcoholism is a contributing factor material to the... benefits terminate due to payment of 36 months of benefits based on disability when drug addiction or...

20 CFR 404.470 - Nonpayment of disability benefits due to noncompliance with rules regarding treatment for drug...

Code of Federal Regulations, 2012 CFR

2012-04-01

... noncompliance with rules regarding treatment for drug addiction or alcoholism. 404.470 Section 404.470 Employees... noncompliance with rules regarding treatment for drug addiction or alcoholism. (a) Suspension of monthly... addiction or alcoholism is a contributing factor material to the determination of disability (as described...

20 CFR 416.1331 - Termination of your disability or blindness payments.

Code of Federal Regulations, 2012 CFR

2012-04-01

... due to 12 consecutive suspension months for failure to comply with treatment for drug addiction or alcoholism. If you are disabled and drug addiction or alcoholism is a contributing factor material to the... benefits terminate due to payment of 36 months of benefits based on disability when drug addiction or...

20 CFR 416.1331 - Termination of your disability or blindness payments.

Code of Federal Regulations, 2013 CFR

2013-04-01

... due to 12 consecutive suspension months for failure to comply with treatment for drug addiction or alcoholism. If you are disabled and drug addiction or alcoholism is a contributing factor material to the... benefits terminate due to payment of 36 months of benefits based on disability when drug addiction or...

20 CFR 404.470 - Nonpayment of disability benefits due to noncompliance with rules regarding treatment for drug...

Code of Federal Regulations, 2011 CFR

2011-04-01

... noncompliance with rules regarding treatment for drug addiction or alcoholism. 404.470 Section 404.470 Employees... noncompliance with rules regarding treatment for drug addiction or alcoholism. (a) Suspension of monthly... addiction or alcoholism is a contributing factor material to the determination of disability (as described...

20 CFR 404.470 - Nonpayment of disability benefits due to noncompliance with rules regarding treatment for drug...

Code of Federal Regulations, 2014 CFR

2014-04-01

... noncompliance with rules regarding treatment for drug addiction or alcoholism. 404.470 Section 404.470 Employees... noncompliance with rules regarding treatment for drug addiction or alcoholism. (a) Suspension of monthly... addiction or alcoholism is a contributing factor material to the determination of disability (as described...

20 CFR 416.1331 - Termination of your disability or blindness payments.

Code of Federal Regulations, 2014 CFR

2014-04-01

... due to 12 consecutive suspension months for failure to comply with treatment for drug addiction or alcoholism. If you are disabled and drug addiction or alcoholism is a contributing factor material to the... benefits terminate due to payment of 36 months of benefits based on disability when drug addiction or...

20 CFR 404.470 - Nonpayment of disability benefits due to noncompliance with rules regarding treatment for drug...

Code of Federal Regulations, 2013 CFR

2013-04-01

... noncompliance with rules regarding treatment for drug addiction or alcoholism. 404.470 Section 404.470 Employees... noncompliance with rules regarding treatment for drug addiction or alcoholism. (a) Suspension of monthly... addiction or alcoholism is a contributing factor material to the determination of disability (as described...

20 CFR 404.316 - When entitlement to disability benefits begins and ends.

Code of Federal Regulations, 2011 CFR

2011-04-01

... benefits for any months in which you do substantial gainful activity. (e) If drug addiction or alcoholism... addiction or alcoholism is not available, months before March 1995, and months for which your benefit.... (f) If drug addiction or alcoholism is a contributing factor material to the determination of...

20 CFR 404.316 - When entitlement to disability benefits begins and ends.

Code of Federal Regulations, 2012 CFR

2012-04-01

... benefits for any months in which you do substantial gainful activity. (e) If drug addiction or alcoholism... addiction or alcoholism is not available, months before March 1995, and months for which your benefit.... (f) If drug addiction or alcoholism is a contributing factor material to the determination of...

20 CFR 404.316 - When entitlement to disability benefits begins and ends.

Code of Federal Regulations, 2013 CFR

2013-04-01

... benefits for any months in which you do substantial gainful activity. (e) If drug addiction or alcoholism... addiction or alcoholism is not available, months before March 1995, and months for which your benefit.... (f) If drug addiction or alcoholism is a contributing factor material to the determination of...

What Affect Student Cognitive Style in the Development of Hypermedia Learning System?

ERIC Educational Resources Information Center

Lee, Catherine Hui Min; Cheng, Yuk Wing; Rai, Shri; Depickere, Arnold

2005-01-01

Recent developments in learning technology such as hypermedia is becoming widespread and offer significant contribution to improve the delivery of learning and teaching materials. A key factor in the development of hypermedia learning system is cognitive style (CS) as it relates to users' information processing habits, representing individual…

Turner Syndrome: Genetic and Hormonal Factors Contributing to a Specific Learning Disability Profile

ERIC Educational Resources Information Center

Rovet, Joanne

2004-01-01

Turner Syndrome (TS) is a genetic disorder affecting primarily females. It arises from a loss of X-chromosome material, most usually one of the two X chromosomes. Affected individuals have a number of distinguishing somatic features, including short stature and ovarian dysgenesis. Individuals with TS show a distinct neurocognitive profile…

Why Do People Share Content? Identifying Why Students Support Sharing Course Material

ERIC Educational Resources Information Center

Tromp, Gerhard Wieger; Long, Phillip D.

2013-01-01

To establish which factors predict student intentions to contribute towards an OpenCourseWare site, an online questionnaire was distributed among University of Queensland students via email. The 320 participants completed items that were based on the theory of planned behaviour and were designed to measure attitudes, subjective norms and perceived…

Country- and individual-level socioeconomic determinants of depression: multilevel cross-national comparison.

PubMed

Rai, Dheeraj; Zitko, Pedro; Jones, Kelvyn; Lynch, John; Araya, Ricardo

2013-03-01

The prevalence and correlates of depression vary across countries. Contextual factors such as country-level income or income inequalities have been hypothesised to contribute to these differences. To investigate associations of depression with socioeconomic factors at the country level (income inequality, gross national income) and individual (education, employment, assets and spending) level, and to investigate their relative contribution in explaining the cross-national variation in the prevalence of depression. Multilevel study using interview data of 187 496 individuals from 53 countries participating in the World Health Organization World Health Surveys. Depression prevalence varied between 0.4 and 15.7% across countries. Individual-level factors were responsible for 86.5% of this variance but there was also reasonable variation at the country level (13.5%), which appeared to increase with decreasing economic development of countries. Gross national income or country-level income inequality had no association with depression. At the individual level, fewer material assets, lower education, female gender, economic inactivity and being divorced or widowed were associated with increased odds of depression. Greater household spending, unlike material assets, was associated with increasing odds of depression (adjusted analysis). The variance of depression prevalence attributable to country-level factors seemed to increase with decreasing economic development of countries. However, country-level income inequality or gross national income explained little of this variation, and individual-level factors appeared more important than contextual factors as determinants of depression. The divergent relationship of assets and spending with depression emphasise that different socioeconomic measures are not interchangeable in their associations with depression.

Mechanism behind the high thermoelectric power factor of SrTiO3 by calculating the transport coefficients

NASA Astrophysics Data System (ADS)

Shirai, Koun; Yamanaka, Kazunori

2013-02-01

The thermoelectric power factor of SrTiO3 is unusually high with respect to its mobility and band gap. Good thermoelectrics usually have high mobility and a narrow band gap, but such properties are not found in SrTiO3. We have determined the mechanism behind the high power factor by calculating the transport coefficients. The key to understanding the power factor is that different effective masses contribute to different transport phenomena. The discrepancy between the effective mass for the conductivity and the thermoelectric power showed that the conductivity and thermoelectric power are conveyed by electrons with different effective masses in the Brillouin zone. Light electrons were responsible for the high conductivity, whereas heavy electrons were responsible for the high thermoelectric power. The high carrier concentrations of more than 1020 cm-3 did not reduce the thermoelectric power of SrTiO3 above the classical limit. This indicates that the electrons carrying the thermoelectric power were not degenerate. This is achieved by a decrease in the Fermi energy and the contribution of the heavy electrons to the Seebeck coefficient. The strong dielectric screening also contributed to the high power factor. The Coulomb scattering by ionized impurities, which would usually reduce the carrier mobility, was effectively screened. These results clarify the mechanism behind the contribution of different types of electrons, and show that high thermoelectric power does not necessarily reduce conductivity. Our findings provide a new direction for the band engineering of thermoelectric materials.

Comparison of VOC and ammonia emissions from individual PVC materials, adhesives and from complete structures.

PubMed

Järnström, H; Saarela, K; Kalliokoski, P; Pasanen, A-L

2008-04-01

Emission rates of volatile organic compounds (VOCs) and ammonia measured from six PVC materials and four adhesives in the laboratory were compared to the emission rates measured on site from complete structures. Significantly higher specific emission rates (SERs) were generally measured from the complete structures than from individual materials. There were large differences between different PVC materials in their permeability for VOCs originating from the underlying structure. Glycol ethers and esters from adhesives used in the installation contributed to the emissions from the PVC covered structure. Emissions of 2-ethylhexanol and TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate) were common. High ammonia SERs were measured from single adhesives but their contribution to the emissions from the complete structure did not appear as obvious as for VOCs. The results indicate that three factors affected the VOC emissions from the PVC flooring on a structure: 1) the permeability of the PVC product for VOCs, 2) the VOC emission from the adhesive used, and 3) the VOC emission from the backside of the PVC product.

Materials for a Stirling engine heater head

NASA Technical Reports Server (NTRS)

Noble, J. E.; Lehmann, G. A.; Emigh, S. G.

1990-01-01

Work done on the 25-kW advanced Stirling conversion system (ASCS) terrestrial solar program in establishing criteria and selecting materials for the engine heater head and heater tubes is described. Various mechanisms contributing to incompatibility between materials are identified and discussed. Large thermal gradients, coupled with requirements for long life (60,000 h at temperature) and a large number of heatup and cooldown cycles (20,000) drive the design from a structural standpoint. The pressurized cylinder is checked for creep rupture, localized yielding, reverse plasticity, creep and fatigue damage, and creep ratcheting, in addition to the basic requirements for bust and proof pressure. In general, creep rupture and creep and fatigue interaction are the dominant factors in the design. A wide range of materials for the heater head and tubes was evaluated. Factors involved in the assessment were strength and effect on engine efficiency, reliability, and cost. A preliminary selection of Inconel 713LC for the heater head is based on acceptable structural properties but driven mainly by low cost. The criteria for failure, the structural analysis, and the material characteristics with basis for selection are discussed.

ECM-Based Materials in Cardiovascular Applications: Inherent Healing Potential and Augmentation of Native Regenerative Processes

PubMed Central

Piterina, Anna V.; Cloonan, Aidan J.; Meaney, Claire L.; Davis, Laura M.; Callanan, Anthony; Walsh, Michael T.; McGloughlin, Tim M.

2009-01-01

The in vivo healing process of vascular grafts involves the interaction of many contributing factors. The ability of vascular grafts to provide an environment which allows successful accomplishment of this process is extremely difficult. Poor endothelisation, inflammation, infection, occlusion, thrombosis, hyperplasia and pseudoaneurysms are common issues with synthetic grafts in vivo. Advanced materials composed of decellularised extracellular matrices (ECM) have been shown to promote the healing process via modulation of the host immune response, resistance to bacterial infections, allowing re-innervation and reestablishing homeostasis in the healing region. The physiological balance within the newly developed vascular tissue is maintained via the recreation of correct biorheology and mechanotransduction factors including host immune response, infection control, homing and the attraction of progenitor cells and infiltration by host tissue. Here, we review the progress in this tissue engineering approach, the enhancement potential of ECM materials and future prospects to reach the clinical environment. PMID:20057951

Interfacial contribution to the dielectric response in semiconducting LaBiMn4/3Co2/3O6

NASA Astrophysics Data System (ADS)

Filippi, M.; Kundys, B.; Ranjith, R.; Kundu, Asish K.; Prellier, W.

2008-05-01

Impedance measurements have been performed on a sintered polycrystalline sample of the perovskite LaBiMn4/3Co2/3O6. Colossal dielectric permittivity is often measured in this class of semiconducting materials as a result of extrinsic factors. Our results show that a large offset in the capacitance, measured on a series of samples with different thickness, is due to the interfacial polarization. This contribution can then be removed from the data, creating a general procedure for dielectric measurements in semiconducting samples.

Technical assessment for quality control of resins

NASA Technical Reports Server (NTRS)

Gosnell, R. B.

1977-01-01

Survey visits to companies involved in the manufacture and use of graphite-epoxy prepregs were conducted to assess the factors which may contribute to variability in the mechanical properties of graphite-epoxy composites. In particular, the purpose was to assess the contributions of the epoxy resins to variability. Companies represented three segments of the composites industry - aircraft manufacturers, prepreg manufacturers, and epoxy resin manufacturers. Several important sources of performance variability were identified from among the complete spectrum of potential sources which ranged from raw materials to composite test data interpretation.

NASA technology utilization survey on composite materials

NASA Technical Reports Server (NTRS)

Leeds, M. A.; Schwartz, S.; Holm, G. J.; Krainess, A. M.; Wykes, D. M.; Delzell, M. T.; Veazie, W. H., Jr.

1972-01-01

NASA and NASA-funded contractor contributions to the field of composite materials are surveyed. Existing and potential non-aerospace applications of the newer composite materials are emphasized. Economic factors for selection of a composite for a particular application are weight savings, performance (high strength, high elastic modulus, low coefficient of expansion, heat resistance, corrosion resistance,), longer service life, and reduced maintenance. Applications for composites in agriculture, chemical and petrochemical industries, construction, consumer goods, machinery, power generation and distribution, transportation, biomedicine, and safety are presented. With the continuing trend toward further cost reductions, composites warrant consideration in a wide range of non-aerospace applications. Composite materials discussed include filamentary reinforced materials, laminates, multiphase alloys, solid multiphase lubricants, and multiphase ceramics. New processes developed to aid in fabrication of composites are given.

Fast Synthesis of Pt Nanocrystals and Pt/Microporous La2O3 Materials Using Acoustic Levitation.

PubMed

Yu, Yinkai; Qu, Shaohua; Zang, Duyang; Wang, Liuding; Wu, Hongjing

2018-02-13

Usually, we must use an appropriate support material to keep the metal species stable and finely dispersed as supported metal nanoparticles for industry application. Therefore, the choice of support material is a key factor in determining the dispersion and particle size of the noble metal species. Here, we report the synthesis of a single-atom Pt material in the solution and supported Pt nanoclusters on microporous La 2 O 3 by a one-step acoustic levitation method without any pretreatment/modification of raw oxide. We have strongly contributed to the synthetic methodology of the surface/interfacial heterogeneous catalysts in this study, and this finding could open another door for synthesis of supported metal nanoparticles on porous materials for environmental catalysis.

Fast Synthesis of Pt Nanocrystals and Pt/Microporous La2O3 Materials Using Acoustic Levitation

NASA Astrophysics Data System (ADS)

Yu, Yinkai; Qu, Shaohua; Zang, Duyang; Wang, Liuding; Wu, Hongjing

2018-02-01

Usually, we must use an appropriate support material to keep the metal species stable and finely dispersed as supported metal nanoparticles for industry application. Therefore, the choice of support material is a key factor in determining the dispersion and particle size of the noble metal species. Here, we report the synthesis of a single-atom Pt material in the solution and supported Pt nanoclusters on microporous La2O3 by a one-step acoustic levitation method without any pretreatment/modification of raw oxide. We have strongly contributed to the synthetic methodology of the surface/interfacial heterogeneous catalysts in this study, and this finding could open another door for synthesis of supported metal nanoparticles on porous materials for environmental catalysis.

The interactive role of income (material position) and income rank (psychosocial position) in psychological distress: a 9-year longitudinal study of 30,000 UK parents.

PubMed

Garratt, Elisabeth A; Chandola, Tarani; Purdam, Kingsley; Wood, Alex M

2016-10-01

Parents face an increased risk of psychological distress compared with adults without children, and families with children also have lower average household incomes. Past research suggests that absolute income (material position) and income status (psychosocial position) influence psychological distress, but their combined effects on changes in psychological distress have not been examined. Whether absolute income interacts with income status to influence psychological distress are also key questions. We used fixed-effects panel models to examine longitudinal associations between psychological distress (measured on the Kessler scale) and absolute income, distance from the regional mean income, and regional income rank (a proxy for status) using data from 29,107 parents included in the UK Millennium Cohort Study (2003-2012). Psychological distress was determined by an interaction between absolute income and income rank: higher absolute income was associated with lower psychological distress across the income spectrum, while the benefits of higher income rank were evident only in the highest income parents. Parents' psychological distress was, therefore, determined by a combination of income-related material and psychosocial factors. Both material and psychosocial factors contribute to well-being. Higher absolute incomes were associated with lower psychological distress across the income spectrum, demonstrating the importance of material factors. Conversely, income status was associated with psychological distress only at higher absolute incomes, suggesting that psychosocial factors are more relevant to distress in more advantaged, higher income parents. Clinical interventions could, therefore, consider both the material and psychosocial impacts of income on psychological distress.

Bone strength in pure bending: bearing of geometric and material properties.

PubMed

Winter, Werner

2008-01-01

Osteoporosis is characterized by decreasing of bone mass and bone strength with advanced age. For characterization of material properties of dense and cellular bone the volumetric bone mineral density (vBMD) is one of the most important contributing factors to bone strength. Often bending tests of whole bone are used to get information about the state of osteoporosis. In a first step, different types of cellular structures are considered to characterize vBMD and its influence to elastic and plastic material properties. Afterwards, the classical theory of plastic bending is used to describe the non-linear moment-curvature relation of a whole bone. For bending of whole bone with sandwich structure an effective second moment of area can be defined. The shape factor as a pure geometrical value is considered to define bone strength. This factor is discussed for a bone with circular cross section and different thickness of cortical bone. The deduced relations and the decrease of material properties are used to demonstrate the influence of osteoporosis to bone bending strength. It can be shown that the elastic and plastic material properties of bone are related to a relative bone mineral density. Starting from an elastic-plastic bone behavior with an constant yield stress the non-linear moment-curvature relation in bending is related to yielding of the fibres in the cross section. The ultimate moment is characterized by a shape factor depending on the geometry of the cross section and on the change of cortical thickness.

Inequality in early childhood neurodevelopment in six poor rural counties of China: a decomposition analysis.

PubMed

Zhang, Cuihong; Zhao, Chunxia; Liu, Xiangyu; Wei, Qianwei; Luo, Shusheng; Guo, Sufang; Zhang, Jingxu; Wang, Xiaoli; Scherpbier, Robert W

2017-12-08

Previous studies about inequality in children's health focused more on physical health than the neurodevelopment. In this study, we aimed to evaluate the inequality in early childhood neurodevelopment in poor rural China and explore the contributions of socioeconomic factors to the inequality. Information of 2120 children aged 0 to 35 months and their households in six poor rural counties of China was collected during July - September, 2013. Age and Stages Questionnaire-Chinese version, concentration index and decomposition analysis were used to assess the neurodevelopment of early childhood, measure its inequality and evaluate the contributions of socioeconomic factors to the inequality, respectively. The prevalence of suspected developmental delay in children under 35 months of age in six poor rural counties of China was nearly 40%, with the concentration index of -0.0877. Household economic status, caregivers' depressive symptoms, learning material and family support for learning were significantly associated with children's suspected developmental delay, and explained 34.1, 14.1, 8.9 and 7.0% of the inequality in early childhood neurodevelopment, respectively. The early childhood neurodevelopment in the surveyed area is poor and unfair. Factors including household economic status, caregivers' depressive symptoms, learning material and family support for learning are significantly associated with children's suspected developmental delay and early developmental inequality. The results highlight the urgent need of monitoring child neurodevelopment in poor rural areas. Interventions targeting the caregivers' depressive symptoms, providing learning material and developmental appropriate stimulating activities may help improve early childhood neurodevelopment and reduce its inequality.

Institutional Culture and OER Policy: How Structure, Culture, and Agency Mediate OER Policy Potential in South African Universities

ERIC Educational Resources Information Center

Cox, Glenda; Trotter, Henry

2016-01-01

Several scholars and organizations suggest that institutional policy is a key enabling factor for academics to contribute their teaching materials as open educational resources (OER). But given the diversity of institutions comprising the higher education sector--and the administrative and financial challenges facing many institutions in the…

The Coherence Formation Model of Illustrated Text Comprehension: A Path Model of Attention to Multimedia Text

ERIC Educational Resources Information Center

Fitzhugh, Shannon Leigh

2012-01-01

The study reported here tests a model that includes several factors thought to contribute to the comprehension of static multimedia learning materials (i.e. background knowledge, working memory, attention to components as measured with eye movement measures). The model examines the effects of working memory capacity, domain specific (biology) and…

20 CFR 416.1326 - Suspension for failure to comply with treatment for drug addiction or alcoholism.

Code of Federal Regulations, 2014 CFR

2014-04-01

... treatment for drug addiction or alcoholism. 416.1326 Section 416.1326 Employees' Benefits SOCIAL SECURITY....1326 Suspension for failure to comply with treatment for drug addiction or alcoholism. (a) Basis for suspension. If you are disabled and drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1326 - Suspension for failure to comply with treatment for drug addiction or alcoholism.

Code of Federal Regulations, 2011 CFR

2011-04-01

... treatment for drug addiction or alcoholism. 416.1326 Section 416.1326 Employees' Benefits SOCIAL SECURITY....1326 Suspension for failure to comply with treatment for drug addiction or alcoholism. (a) Basis for suspension. If you are disabled and drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1326 - Suspension for failure to comply with treatment for drug addiction or alcoholism.

Code of Federal Regulations, 2012 CFR

2012-04-01

... treatment for drug addiction or alcoholism. 416.1326 Section 416.1326 Employees' Benefits SOCIAL SECURITY....1326 Suspension for failure to comply with treatment for drug addiction or alcoholism. (a) Basis for suspension. If you are disabled and drug addiction or alcoholism is a contributing factor material to the...

20 CFR 416.1326 - Suspension for failure to comply with treatment for drug addiction or alcoholism.

Code of Federal Regulations, 2013 CFR

2013-04-01

... treatment for drug addiction or alcoholism. 416.1326 Section 416.1326 Employees' Benefits SOCIAL SECURITY....1326 Suspension for failure to comply with treatment for drug addiction or alcoholism. (a) Basis for suspension. If you are disabled and drug addiction or alcoholism is a contributing factor material to the...

The State of the Economy: Resources and Costs for Educational Services.

ERIC Educational Resources Information Center

Burkhead, Jesse

It is most difficult to believe that the American economy can soon return to the stable growth rates that were enjoyed from 1958 to 1973. Factors that contribute to a slow-growth economy include changes in the age of the average citizen, pressures for larger expenditures for armaments, pricefixing by oligopolies, rising raw materials prices,…

Academic Commitment and Self-Efficacy as Predictors of Academic Achievement in Additional Materials Science

ERIC Educational Resources Information Center

Vogel, F. Ruric; Human-Vogel, Salomé

2016-01-01

A great deal of research within science and engineering education revolves around academic success and retention of science and engineering students. It is well known that South Africa is experiencing, for various reasons, an acute shortage of engineers. Therefore, we think it is important to understand the factors that contribute to attrition…

Heritability of Lower Urinary Tract Symptoms in Men: A Twin Study

PubMed Central

Afari, Niloofar; Gasperi, Marianna; Forsberg, Christopher W.; Goldberg, Jack; Buchwald, Dedra; Krieger, John N.

2016-01-01

Purpose Symptoms of urinary irritation, urgency, frequency, and obstruction, known as lower urinary tract symptoms (LUTS), are common in urological practice. However, little is known about the etiology or pathogenesis of LUTS, especially the relative contributions of genetic and environmental factors to development of these symptoms. We used a classical twin study design to examine the relative contribution of genetic and environmental factors to the occurrence of LUTS in middle-aged men. Materials and Methods Twins were members of the Vietnam Era Twin (VET) Registry. We used a mail survey to collect lower urinary tract symptoms (LUTS) using the International Prostate Symptom Score (I-PSS) instrument. Twin correlations and biometric modeling was used to determine the relative genetic and environmental contributions to variance in I-PSS total score and individual items. Results Participants were 1,002 monozygotic and 580 dizygotic middle-aged male twin pairs (mean age = 50.2 years; S.D. = 3.0 years). Nearly 25% of the sample had an I-PSS score > 8, indicating at least moderate LUTS. The heritability of the total I-PSS was 37% (95% CI = 32-42%). Heritability estimates ranged from 21% for nocturia to 40% for straining, with moderate heritability (34–36%) for urinary frequency and urgency. Conclusions Genetic factors provide a moderate contribution (20–40%) to LUTS in middle-aged men, suggesting that environmental factors may also contribute substantially to LUTS. Future research is needed to define specific genetic and environmental mechanisms that underlie the development of these symptoms and conditions associated with LUTS. PMID:27312318

Factors contributing to the temperature beneath plaster or fiberglass cast material

PubMed Central

Hutchinson, Michael J; Hutchinson, Mark R

2008-01-01

Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints), brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period). Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of Celsius for over 20 minutes. Conclusion Clinicians should be cautious when applying thick casts with warm dip water. Fast setting plasters have increased risk of thermal injury while brand does not appear to play a significant role. Prefabricated fiberglass splints appear to be safer than circumferential casts. The greatest risk of thermal injury occurs when thick casts are allowed to mature while resting on pillow. PMID:18298851

Causal reports: Context-dependent contributions of intuitive physics and visual impressions of launching.

PubMed

Vicovaro, Michele

2018-05-01

Everyday causal reports appear to be based on a blend of perceptual and cognitive processes. Causality can sometimes be perceived automatically through low-level visual processing of stimuli, but it can also be inferred on the basis of an intuitive understanding of the physical mechanism that underlies an observable event. We investigated how visual impressions of launching and the intuitive physics of collisions contribute to the formation of explicit causal responses. In Experiment 1, participants observed collisions between realistic objects differing in apparent material and hence implied mass, whereas in Experiment 2, participants observed collisions between abstract, non-material objects. The results of Experiment 1 showed that ratings of causality were mainly driven by the intuitive physics of collisions, whereas the results of Experiment 2 provide some support to the hypothesis that ratings of causality were mainly driven by visual impressions of launching. These results suggest that stimulus factors and experimental design factors - such as the realism of the stimuli and the variation in the implied mass of the colliding objects - may determine the relative contributions of perceptual and post-perceptual cognitive processes to explicit causal responses. A revised version of the impetus transmission heuristic provides a satisfactory explanation for these results, whereas the hypothesis that causal responses and intuitive physics are based on the internalization of physical laws does not. Copyright © 2018 Elsevier B.V. All rights reserved.

Examining Material Hardship in Mothers: Associations of Diaper Need and Food Insufficiency with Maternal Depressive Symptoms.

PubMed

Austin, Anna E; Smith, Megan V

2017-01-01

Objectives: Material hardship represents a potential mechanism by which poverty influences the mental health of mothers. This study examined the association between two forms of material hardship, diaper need and food insufficiency, and maternal depressive symptoms. Methods: Data were from a cross-sectional study of 296 urban, pregnant or parenting, low-income women. A linear regression model was used to examine the association of maternal depressive symptoms, measured by the Center for Epidemiologic Studies Depression (CES-D) score, with diaper need and food insufficiency, after adjustment for demographic factors. Results: More than half of women reported diaper need (50.3%) and food insufficiency (54.7%). Nearly one-third of women who reported diaper need did not report food insufficiency (32.2%). In bivariate analyses, diaper need and food insufficiency were associated with maternal CES-D score. In multivariate analyses, women who reported diaper need had a significantly higher CES-D score than women who did not report diaper need (β=3.5, p =0.03). Women who reported food insufficiency did not have a significantly higher CES-D score than women who did not report food insufficiency (β=2.4, p =0.15). Conclusions: Diaper need is a form of material hardship that has received little attention in the research literature. Diapers, unlike food, are currently not an allowable expense in U.S. antipoverty programs. Diaper need may contribute to maternal depressive symptoms, beyond the contribution of other forms of material hardship, because there are no supports in place to provide assistance meeting this basic need. Importantly, diaper need is a malleable factor amenable to public health and policy interventions.

Examining Material Hardship in Mothers: Associations of Diaper Need and Food Insufficiency with Maternal Depressive Symptoms

PubMed Central

Austin, Anna E.; Smith, Megan V.

2017-01-01

Abstract Objectives: Material hardship represents a potential mechanism by which poverty influences the mental health of mothers. This study examined the association between two forms of material hardship, diaper need and food insufficiency, and maternal depressive symptoms. Methods: Data were from a cross-sectional study of 296 urban, pregnant or parenting, low-income women. A linear regression model was used to examine the association of maternal depressive symptoms, measured by the Center for Epidemiologic Studies Depression (CES-D) score, with diaper need and food insufficiency, after adjustment for demographic factors. Results: More than half of women reported diaper need (50.3%) and food insufficiency (54.7%). Nearly one-third of women who reported diaper need did not report food insufficiency (32.2%). In bivariate analyses, diaper need and food insufficiency were associated with maternal CES-D score. In multivariate analyses, women who reported diaper need had a significantly higher CES-D score than women who did not report diaper need (β=3.5, p=0.03). Women who reported food insufficiency did not have a significantly higher CES-D score than women who did not report food insufficiency (β=2.4, p=0.15). Conclusions: Diaper need is a form of material hardship that has received little attention in the research literature. Diapers, unlike food, are currently not an allowable expense in U.S. antipoverty programs. Diaper need may contribute to maternal depressive symptoms, beyond the contribution of other forms of material hardship, because there are no supports in place to provide assistance meeting this basic need. Importantly, diaper need is a malleable factor amenable to public health and policy interventions. PMID:29082357

Educational differences in leisure-time physical inactivity: a descriptive and explanatory study.

PubMed

Droomers, M; Schrijvers, C T; van de Mheen, H; Mackenbach, J P

1998-12-01

In this study we aim to explain educational differences in leisure-time physical inactivity in terms of psychosocial and material factors. Cross-sectional data were obtained from the baseline of the Dutch GLOBE study in 1991, including 2598 men and women, aged 15-74 years. Physical inactivity during leisure time was defined as not participating in any activity, such as sports, gardening, walking or cycling. Psychosocial factors included in the study were coping resources, personality, and stressors. Material factors were financial situation, employment status, and living conditions. Logistic regression models were used to calculate educational differences in physical inactivity. Physical inactivity was more prevalent in lower educational groups. Psychosocial factors related to physical inactivity were locus of control, parochialism, neuroticism, emotional social support, active problem focussing, optimistic and palliative coping styles. Material factors associated with physical inactivity were income, employment status and financial problems. All correlates of physical inactivity were unequally distributed over educational groups, except optimistic and palliative coping. Personality and coping style were the main contributors to the observed educational differences in physical inactivity. That is to say, parochialism, locus of control, neuroticism and active problem focussing explained about half of elevated odds ratios of physical inactivity in the lower educational groups. The material factors, equivalent income and employment status explained about 40% of the elevated odds ratios. Psychosocial and material correlates together reduced the odds ratios of lower educational groups by on average 75%. These results have practical consequences for the design of more effective interventions to promote physical activity. In particular, personality and coping style of risk groups, such as lower educational groups, should be taken into consideration at the future development of these interventions, as well as inequalities in material restrictions related to engaging in physical activity. Supplementary interventions focussing on childhood conditions which, partly, influence both personality and physical inactivity may also contribute to a reduction of socio-economic differences in physical inactivity.

The prevalence of asthma risk and contributing factors in underserved Vietnamese children in Orange County, CA.

PubMed

Nguyen, Tan; Kilgore, David; Morphew, Tricia; Tran, Jacqueline; Berg, Jill; Galant, Stanley

2015-01-01

Vietnamese constitutes one of the fastest growing minority groups in America, with the largest concentration in Orange County (OC), CA. Yet, there are limited data on the prevalence of asthma in Vietnamese children. Our study evaluated the risk of asthma and key contributing factors among these children living in OC, CA. Five elementary schools in OC that were predominantly Vietnamese with low socioeconomic status were selected for participation. Validated surveys were sent to parents of all students ages 3-12 in these schools with materials available in English, Vietnamese and Spanish. Surveys included questions to identify the risk of asthma and related key factors. Surveys were completed by parents and returned to schools. There were 1530 participants eligible for analysis. Asthma risk was 30.4%, and of these, 22.6% had no prior diagnosis. Contributing factors to identification of those at risk were male gender (p < 0.001), preferred use of the Vietnamese language (p = 0.004), longer duration in the United States (p = 0.019), and smoker in the household (p = 0.015). The prevalence of asthma risk in our community of low socioeconomic status Vietnamese children was found to be higher than commonly appreciated. Furthermore, a considerable number of these children had not been previously diagnosed. Given the limited information in this population, our current findings of asthma risk and key contributing factors could affect health care policies that allow appropriate funding for programs dedicated to asthma care in this and other growing population.

Quantitative Analysis of Critical Factors for the Climate Impact of Landfill Mining.

PubMed

Laner, David; Cencic, Oliver; Svensson, Niclas; Krook, Joakim

2016-07-05

Landfill mining has been proposed as an innovative strategy to mitigate environmental risks associated with landfills, to recover secondary raw materials and energy from the deposited waste, and to enable high-valued land uses at the site. The present study quantitatively assesses the importance of specific factors and conditions for the net contribution of landfill mining to global warming using a novel, set-based modeling approach and provides policy recommendations for facilitating the development of projects contributing to global warming mitigation. Building on life-cycle assessment, scenario modeling and sensitivity analysis methods are used to identify critical factors for the climate impact of landfill mining. The net contributions to global warming of the scenarios range from -1550 (saving) to 640 (burden) kg CO2e per Mg of excavated waste. Nearly 90% of the results' total variation can be explained by changes in four factors, namely the landfill gas management in the reference case (i.e., alternative to mining the landfill), the background energy system, the composition of the excavated waste, and the applied waste-to-energy technology. Based on the analyses, circumstances under which landfill mining should be prioritized or not are identified and sensitive parameters for the climate impact assessment of landfill mining are highlighted.

A New Approach for Quantitative Evaluation of Ultrasonic Wave Attenuation in Composites

NASA Astrophysics Data System (ADS)

Ni, Qing-Qing; Li, Ran; Xia, Hong

2017-02-01

When ultrasonic waves propagate in composite materials, the propagation behaviors result from the combination effects of various factors, such as material anisotropy and viscoelastic property, internal microstructure and defects, incident wave characteristics and interface condition between composite components. It is essential to make it clear how these factors affect the ultrasonic wave propagation and attenuation characteristics, and how they mutually interact on each other. In the present paper, based on a newly developed time-domain finite element analysis code, PZflex, a unique approach for clarifying the detailed influence mechanism of aforementioned factors is proposed, in which each attenuation component can be extracted from the overall attenuation and analyzed respectively. By taking into consideration the interrelation between each individual attenuation component, the variation behaviors of each component and internal dynamic stress distribution against material anisotropy and matrix viscosity are separately and quantitatively evaluated. From the detailed analysis results of each attenuation component, the energy dissipation at interface is a major component in ultrasonic wave attenuation characteristics, which can provide a maximum contribution rate of 68.2 % to the overall attenuation, and each attenuation component is closely related to the material anisotropy and viscoelasticity. The results clarify the correlation between ultrasonic wave propagation characteristics and material viscoelastic properties, which will be useful in the further development of ultrasonic technology in defect detection.

A conceptual model for quantifying connectivity using graph theory and cellular (per-pixel) approach

NASA Astrophysics Data System (ADS)

Singh, Manudeo; Sinha, Rajiv; Tandon, Sampat K.

2016-04-01

The concept of connectivity is being increasingly used for understanding hydro-geomorphic processes at all spatio-temporal scales. Connectivity is defined as the potential for energy and material flux (water, sediments, nutrients, heat, etc.) to navigate within or between the landscape systems and has two components, structural connectivity and dynamic connectivity. Structural connectivity is defined by the spatially connected features (physical linkages) through which energy and materials flow. Dynamic connectivity is a process defined connectivity component. These two connectivity components also interact with each other by forming a feedback system. This study attempts to explore a method to quantify structural and dynamic connectivity. In fluvial transport systems, sediment and water can flow in either a diffused manner or in a channelized way. At all the scales, hydrological and sediment fluxes can be tracked using a cellular (per-pixel) approach and can be quantified using graphical approach. The material flux, slope and LULC (Land Use Land Cover) weightage factors of a pixel together determine if it will contribute towards connectivity of the landscape/system. In a graphical approach, all the contributing pixels will form a node at their centroid and this node will be connected to the next 'down-node' via a directed edge with 'least cost path'. The length of the edge will depend on the desired spatial scale and its path direction will depend on the traversed pixel's slope and the LULC (weightage) factors. The weightage factors will lie in-between 0 to 1. This value approaches 1 for the LULC factors which promote connectivity. For example, in terms of sediment connectivity, the weightage could be RUSLE (Revised Universal Soil Loss Equation) C-factors with bare unconsolidated surfaces having values close to 1. This method is best suited for areas with low slopes, where LULC can be a deciding as well as dominating factor. The degree of connectivity and its pathways will show changes under different LULC conditions even if the slope remains the same. The graphical approach provides the statistics of connected and disconnected graph elements (edges, nodes) and graph components, thereby allowing the quantification of structural connectivity. This approach also quantifies the dynamic connectivity by allowing the measurement of the fluxes (e.g. via hydrographs or sedimentographs) at any node as well as at any system outlet. The contribution of any sub-system can be understood by removing the remaining sub-systems which can be conveniently achieved by masking associated graph elements.

A protocol for lifetime energy and environmental impact assessment of building insulation materials

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

Shrestha, Som S., E-mail: shresthass@ornl.gov; Biswas, Kaushik; Desjarlais, Andre O.

This article describes a proposed protocol that is intended to provide a comprehensive list of factors to be considered in evaluating the direct and indirect environmental impacts of building insulation materials, as well as detailed descriptions of standardized calculation methodologies to determine those impacts. The energy and environmental impacts of insulation materials can generally be divided into two categories: (1) direct impact due to the embodied energy of the insulation materials and other factors and (2) indirect or environmental impacts avoided as a result of reduced building energy use due to addition of insulation. Standards and product category rules exist,more » which provide guidelines about the life cycle assessment (LCA) of materials, including building insulation products. However, critical reviews have suggested that these standards fail to provide complete guidance to LCA studies and suffer from ambiguities regarding the determination of the environmental impacts of building insulation and other products. The focus of the assessment protocol described here is to identify all factors that contribute to the total energy and environmental impacts of different building insulation products and, more importantly, provide standardized determination methods that will allow comparison of different insulation material types. Further, the intent is not to replace current LCA standards but to provide a well-defined, easy-to-use comparison method for insulation materials using existing LCA guidelines. - Highlights: • We proposed a protocol to evaluate the environmental impacts of insulation materials. • The protocol considers all life cycle stages of an insulation material. • Both the direct environmental impacts and the indirect impacts are defined. • Standardized calculation methods for the ‘avoided operational energy’ is defined. • Standardized calculation methods for the ‘avoided environmental impact’ is defined.« less

Density of Spray-Formed Materials

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

Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

2008-06-01

Spray Forming is an advanced materials processing technology that transforms molten metal into a near-net-shape solid by depositing atomized droplets onto a substrate. Depending on the application, the spray-formed material may be used in the as-deposited condition or it may undergo post-deposition processing. Regardless, the density of the as-deposited material is an important issue. Porosity is detrimental because it can significantly reduce strength, toughness, hardness and other properties. While it is not feasible to achieve fully-dense material in the as-deposited state, density greater than 99% of theoretical density is possible if the atomization and impact conditions are optimized. Thermal conditionsmore » at the deposit surface and droplet impact angle are key processing parameters that influence the density of the material. This paper examines the factors that contribute to porosity formation during spray forming and illustrates that very high as-deposited density is achieved by optimizing processing parameters.« less

Consumer perceptions on sustainable practices implemented in foodservice organizations in Korea

PubMed Central

Ju, Seyoung

2016-01-01

BACKGROUND/OBJECTIVES Sustainable practices in foodservice organizations including commercial and noncommercial ones are critical to ensure the protection of the environment for the future. With the rapid growth of the foodservice industry, wiser usage of input sources such as food, utilities, and single use packaging should be reconsidered for future generations. Therefore, this study aims to investigate the customer's perceptions on sustainable practices and to identify the relationship among sustainable practices, social contribution and purchase intention. SUBJECTS/METHODS The study was conducted using content analyses by reviewing articles on sustainable food service practices published domestically and abroad. Thereafter, data were collected with a face-to-face survey using a questionnaire and analyzed with factor analyses and multiple regressions. RESULTS Sustainable practices classified with factor analysis consisted of 6 dimensions of green food material procurement, sustainable food preparation, green packaging, preservation of energy, waste management, and public relations on green activity, with a total of 25 green activities in foodservice operations. Consumers were not very familiar with the green activities implemented in the foodservice unit, with the lowest awareness of "green food material procurement (2.46 out of 5 points)", and the highest awareness of "green packaging (3.74)" and "waste management (3.28). The factors influencing the perception of social contribution by foodservice organizations among 6 sustainable practice dimensions were found to be public relations on green activity (β = 0.154), waste management (β = 0.204) and sustainable food preparation (β = 0.183). Green packaging (β = 0.107) and the social contribution of the foodservice organization (β = 0.761) had strong relationships with the image of the organization. The purchase intentions of customers was affected only by the foodservice image (β = 0.775). CONCLUSIONS The results of this study suggest that sustainable practices by foodservice organization present a good image to customers and increase the awareness of valuable contributions that benefit the customer as well as the community. PMID:26865923

PM2.5 Source Apportionment: Reconciling Receptor Models for U.S. Nonurban and Urban Long-Term Networks.

PubMed

Chen, L-W Antony; Watson, John G; Chow, Judith C; DuBois, Dave W; Herschberger, Lisa

2011-11-01

Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter ≤2.5 μm (PM 2.5 ) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM 2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM 2.5 mass (50-69%). Mobile sources outweigh area sources at urban sites, and vice versa at rural sites due to traffic emissions. Gasoline and diesel contributions can be separated using data from the STN, despite significant uncertainties. Major differences between MPSAS and earlier studies on similar environments appear to be the type and magnitude of stationary sources, but these sources are generally minor (<7%) in this and other studies. Ensemble back-trajectory analysis shows that the lower Midwestern states are the predominant source region for secondary ammoniated sulfate in Minnesota. It also suggests substantial contributions of biomass burning and soil dust from out-of-state on occasions, although a quantitative separation of local and regional contributions was not achieved in the current study. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a summary of input data, Unmix and PMF factor profiles, and additional maps. [Box: see text].

Consumer perceptions on sustainable practices implemented in foodservice organizations in Korea.

PubMed

Ju, Seyoung; Chang, Hyeja

2016-02-01

Sustainable practices in foodservice organizations including commercial and noncommercial ones are critical to ensure the protection of the environment for the future. With the rapid growth of the foodservice industry, wiser usage of input sources such as food, utilities, and single use packaging should be reconsidered for future generations. Therefore, this study aims to investigate the customer's perceptions on sustainable practices and to identify the relationship among sustainable practices, social contribution and purchase intention. The study was conducted using content analyses by reviewing articles on sustainable food service practices published domestically and abroad. Thereafter, data were collected with a face-to-face survey using a questionnaire and analyzed with factor analyses and multiple regressions. Sustainable practices classified with factor analysis consisted of 6 dimensions of green food material procurement, sustainable food preparation, green packaging, preservation of energy, waste management, and public relations on green activity, with a total of 25 green activities in foodservice operations. Consumers were not very familiar with the green activities implemented in the foodservice unit, with the lowest awareness of "green food material procurement (2.46 out of 5 points)", and the highest awareness of "green packaging (3.74)" and "waste management (3.28). The factors influencing the perception of social contribution by foodservice organizations among 6 sustainable practice dimensions were found to be public relations on green activity (β = 0.154), waste management (β = 0.204) and sustainable food preparation (β = 0.183). Green packaging (β = 0.107) and the social contribution of the foodservice organization (β = 0.761) had strong relationships with the image of the organization. The purchase intentions of customers was affected only by the foodservice image (β = 0.775). The results of this study suggest that sustainable practices by foodservice organization present a good image to customers and increase the awareness of valuable contributions that benefit the customer as well as the community.

Modeling gamma radiation dose in dwellings due to building materials.

PubMed

de Jong, Peter; van Dijk, Willem

2008-01-01

A model is presented that calculates the absorbed dose rate in air of gamma radiation emitted by building materials in a rectangular body construction. The basis for these calculations is formed by a fixed set of specific absorbed dose rates (the dose rate per Bq kg(-1) 238U, 232Th, and 40K), as determined for a standard geometry with the dimensions 4 x 5 x 2.8 m3. Using the computer codes Marmer and MicroShield, correction factors are assessed that quantify the influence of several room and material related parameters on the specific absorbed dose rates. The investigated parameters are the position in the construction; the thickness, density, and dimensions of the construction parts; the contribution from the outer leave; the presence of doors and windows; the attenuation by internal partition walls; the contribution from building materials present in adjacent rooms; and the effect of non-equilibrium due to 222Rn exhalation. To verify the precision, the proposed method is applied to three Dutch reference dwellings, i.e., a row house, a coupled house, and a gallery apartment. The averaged difference with MCNP calculations is found to be 4%.

Durable wood bonding with epoxy adhesives

Treesearch

Charles R. Frihart

2003-01-01

Although wood was one of the earliest materials to be adhesively bonded, the factors that contribute to strong wood bonds are still not well understood. Wood is a very complex substrate in that it is non-uniform in most aspects. On the macro scale, it is a porous structure with different sized and shaped voids for fluid flow. The structural cells contain four different...

Wood as a strategic material

Treesearch

Kenneth S. Rolston

1977-01-01

Over the medium and long run timber can provide a major contribution to improving the balance of payments caused by the increase in oil prices. It can do so without causing severe shortages at home. This is basically the position held by most senior executives in the forest industry and I'll try to discuss briefly some of the factors necessary to fulfillment of...

Scaffolding, Analysis and Materials: Contributing Factors in an Unexpected Finding of Advanced Infant/Toddler Pretend Play?

ERIC Educational Resources Information Center

Morrissey, Anne-Marie

2014-01-01

As part of a longitudinal study, infant/toddler pretend play development and maternal play modelling were investigated in dyadic context. A total of 21 children were videotaped in monthly play sessions with their mothers, from age 8 to 17 months. Child and mother pretend play frequencies and levels were measured using Brown's Pretend Play…

What Predicts Student Success in Introductory Data Management Classes? An Investigation of Demographic, Personality, Computer-Related, and Interaction Variables

ERIC Educational Resources Information Center

Harris, Kenneth J.; Harris, Ranida B.; Lambert, Alysa D.

2011-01-01

Introduction to data management classes are often times students' first exposure to advanced material in these areas. Many factors are likely to influence success in these classes, but empirical investigations have focused on relatively few variables. In this study, we extend this research by examining the relative contributions of the previously…

Perception by French Students of the Gendered Nature of Material Artifacts Studied in Technology Education

ERIC Educational Resources Information Center

Colette, Andreucci; Marjolaine, Chatoney

2017-01-01

Many studies have shown the importance of the socio-cultural factors that lead girls to desert scientific and technological courses. Over a long period, the contents of the French technology education (TE) college curricula may well have contributed to strengthening the feeling among girls that this discipline was better suited to boys. The choice…

Composition and Source Identification of Chemical Species in Dust from Selected Indoor Environments in Ile-Ife, Nigeria

NASA Astrophysics Data System (ADS)

Ogundele, Lasun T.; Olasinde, Roseline T.; Owoade, Oyediran K.; Olise, Felix S.

2018-05-01

This study presents the elemental compositions and concentrations of indoor dust and identifies the major sources in some selected indoor environments in Ile-Ife, Nigeria. The dust samples were collected from 16 indoor environments comprising offices, churches, residential and staff quarters using a cyclonic high power vacuum cleaner. The dust samples were analyzed for elemental concentrations using x-ray fluorescences. The data sets were analyzed for the possible sources and their contributions using Principal Component Factor Analysis (PCFA). The result showed that dust samples contained several elements: K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Ga, As, Rb, Sr, Se, Zr, V, and Sc. The PCFA identified three factors with the percentage variance of 92, 77, 71 and 68%, for the office, church, residential, and staff quarters, respectively, for the combined elemental data of each of the site classes. The identified sources were track-in-soil, road and windblown soil dust, paint debris, household dust from personal care materials, cooking, and cleaning activities. The unintentional track-in-soil due to mobility of the occupants, structural materials, and outdoor air was the major sources contributing to the indoor dust.

Characterization and source identification of pollutants in runoff from a mixed land use watershed using ordination analyses.

PubMed

Lee, Dong Hoon; Kim, Jin Hwi; Mendoza, Joseph A; Lee, Chang Hee; Kang, Joo-Hyon

2016-05-01

While identification of critical pollutant sources is the key initial step for cost-effective runoff management, it is challenging due to the highly uncertain nature of runoff pollution, especially during a storm event. To identify critical sources and their quantitative contributions to runoff pollution (especially focusing on phosphorous), two ordination methods were used in this study: principal component analysis (PCA) and positive matrix factorization (PMF). For the ordination analyses, we used runoff quality data for 14 storm events, including data for phosphorus, 11 heavy metal species, and eight ionic species measured at the outlets of subcatchments with different land use compositions in a mixed land use watershed. Five factors as sources of runoff pollutants were identified by PCA: agrochemicals, groundwater, native soils, domestic sewage, and urban sources (building materials and automotive activities). PMF identified similar factors to those identified by PCA, with more detailed source mechanisms for groundwater (i.e., nitrate leaching and cation exchange) and urban sources (vehicle components/motor oils/building materials and vehicle exhausts), confirming the sources identified by PCA. PMF was further used to quantify contributions of the identified sources to the water quality. Based on the results, agrochemicals and automotive activities were the two dominant and ubiquitous phosphorus sources (39-61 and 16-47 %, respectively) in the study area, regardless of land use types.

Advances in Lead-Free Piezoelectric Materials for Sensors and Actuators

PubMed Central

Aksel, Elena; Jones, Jacob L.

2010-01-01

Piezoelectrics have widespread use in today’s sensor and actuator technologies. However, most commercially available piezoelectric materials, e.g., Pb [ZrxTi1−x] O3 (PZT), are comprised of more than 60 weight percent lead (Pb). Due to its harmful effects, there is a strong impetus to identify new lead-free replacement materials with comparable properties to those of PZT. This review highlights recent developments in several lead-free piezoelectric materials including BaTiO3, Na0.5Bi0.5TiO3, K0.5Bi0.5TiO3, Na0.5K0.5NbO3, and their solid solutions. The factors that contribute to strong piezoelectric behavior are described and a summary of the properties for the various systems is provided. PMID:22294907

Thinker, Soldier, Scribe: cross-sectional study of researchers' roles and author order in the Annals of Internal Medicine

PubMed Central

Perneger, Thomas V; Poncet, Antoine; Carpentier, Marc; Agoritsas, Thomas; Combescure, Christophe; Gayet-Ageron, Angèle

2017-01-01

Objective How researchers’ contributions relate to author order on the byline remains unclear. We sought to identify researchers’ contributions associated with author order, and to explore the existence of author profiles. Design Observational study. Setting Published record. Participants 1139 authors of 119 research articles published in 2015 in the Annals of Internal Medicine. Primary outcomes Presence or absence of 10 contributions, reported by each author, published in the journal. Results On average, first authors reported 7.1 contributions, second authors 5.2, middle authors 4.0, penultimate authors 4.5 and last authors 6.4 (p<0.001). The first author made the greatest contributions to drafting the article, designing the study, analysing and interpreting the data, and providing study materials or patients. The second author contributed to data analysis as well and to drafting the article. The last author was most involved in obtaining the funding, critically revising the article, designing the study and providing support. Factor analysis yielded three author profiles—Thinker (study design, revision of article, obtaining funding), Soldier (providing material or patients, providing administrative and logistical support, collecting data) and Scribe (analysis and interpretation of data, drafting the article, statistical expertise). These profiles do not strictly correspond to byline position. Conclusions First, second and last authors of research articles made distinct contributions to published research. Three authorship profiles can be used to summarise author contributions. These findings shed light on the organisation of clinical research teams and may help researchers discuss, plan and report authorship in a more transparent way. PMID:28647720

Novel approach for calculating the charge carrier mobility and Hall factor for semiconductor materials

NASA Astrophysics Data System (ADS)

Colibaba, G. V.

2018-06-01

The additive Matthiessen's rule is the simplest and most widely used rule for the rapid experimental characterization and modeling of the charge carrier mobility. However, the error when using this rule can be higher than 40% and the contribution of the assumed additional scattering channels due to the difference between the experimental data and results calculated based on this rule can be misestimated by several times. In this study, a universal semi-additive equation is proposed for the total mobility and Hall factor, which is applicable to any quantity of scattering mechanisms, where it considers the energy dependence of the relaxation time and the error is 10-20 times lower compared with Matthiessen's rule. Calculations with accuracy of 99% are demonstrated for materials with polar-optical phonon, acoustic phonon via the piezoelectric potential, ionized, and neutral impurity scattering. The proposed method is extended to the deformation potential, dislocation, localized defect, alloy potential, and dipole scattering, for nondegenerate and partially degenerate materials.

Michel Borghini as a Mentor and Father of the Theory of Polarization in Polarized Targets

NASA Astrophysics Data System (ADS)

de Boer, Wim

2016-02-01

This paper is a contribution to the memorial session for Michel Borghini at the Spin 2014 conference in Bejing, honoring his pivotal role for the development of polarized targets in high energy physics. Borghini proposed for the first time the correct mechanism for dynamic polarization in polarized targets using organic materials doped with free radicals. In these amorphous materials the spin levels are broadened by spin-spin interactions and g-factor anisotropy, which allows a high dynamic polarization of nuclei by cooling of the spin-spin interaction reservoir. In this contribution I summarize the experimental evidence for this mechanism. These pertinent experiments were done at CERN in the years 1971 - 1974, when I was a graduate student under the guidance of Michel Borghini. I finish by shortly describing how Borghini’s spin temperature theory is now applied in cancer therapy.

Structural Polymer-Based Carbon Nanotube Composite Fibers: Understanding the Processing–Structure–Performance Relationship

PubMed Central

Song, Kenan; Zhang, Yiying; Meng, Jiangsha; Green, Emily C.; Tajaddod, Navid; Li, Heng; Minus, Marilyn L.

2013-01-01

Among the many potential applications of carbon nanotubes (CNT), its usage to strengthen polymers has been paid considerable attention due to the exceptional stiffness, excellent strength, and the low density of CNT. This has provided numerous opportunities for the invention of new material systems for applications requiring high strength and high modulus. Precise control over processing factors, including preserving intact CNT structure, uniform dispersion of CNT within the polymer matrix, effective filler–matrix interfacial interactions, and alignment/orientation of polymer chains/CNT, contribute to the composite fibers’ superior properties. For this reason, fabrication methods play an important role in determining the composite fibers’ microstructure and ultimate mechanical behavior. The current state-of-the-art polymer/CNT high-performance composite fibers, especially in regards to processing–structure–performance, are reviewed in this contribution. Future needs for material by design approaches for processing these nano-composite systems are also discussed. PMID:28809290

Primary role of the electrostatic contributions in a rational growth of hysteresis loop in spin-crossover Fe(II) complexes.

PubMed

Kepenekian, Mikaël; Le Guennic, Boris; Robert, Vincent

2009-08-19

We report a comprehensive analysis of the hysteresis behavior in a series of well-characterized spin-crossover Fe(II) materials. On the basis of the available X-ray data and multireference CASSCF (complete active space self-consistent field) calculations, we show that the growth of the hysteresis loop is controlled by electrostatic contributions. These environment effects turn out to be deeply modified as the crystal structure changes along the spin transition. Our theoretical inspection demonstrates the synergy between weak bonds and electrostatic interactions in the growth of hysteresis behavior. Quantitatively, it is suggested that the electrostatic contributions significantly enhance the cooperativity factor while weak bonds are determinant in the structuration of the 3D networks. Our picture does not rely on any parametrization but uses the microscopic information to derive an expression for the cooperativity parameter. The calculated values are in very good agreement with the experimental observations. Such inspection can thus be carried out to anticipate the hysteresis behavior of this intriguing class of materials.

Eating Disorders and Their Associated Risk Factors among Iranian Population – A Community Based Study

PubMed Central

Garrusi, Behshid; Baneshi, Mohammad Reza

2013-01-01

Backgrounds: Many socio cultural variables could be affect eating disorders in Asian countries. In Iran, there are few researches regarding eating disorders and their contributing factors. The aim of this study is to explore frequency of eating disorders and their risk factors in an Iranian population. Materials and Methods: About 1204 participants were selected aged between fourteen to 55 years. Frequency of eating disorders and effects of variables such as demographic characteristics, Body Mass Index (BMI), use of media, body dissatisfaction, self-esteem, social comparison and social pressure for thinness in individuals with and without eating disorders, were assessed. Findings: The prevalence of eating disorders was 11.5% that included 0.8% anorexia nervosa, 6.2% full threshold bulimia nervosa, 1.4% sub threshold anorexia nervosa and 30% sub threshold binge eating disorder. Symptoms of bulimic syndrome were greater in males. Conclusion: In Iran, eating disorders and related problems are new issue that could be mentioned seriously The identification of these disorders and their related contributing factors are necessity of management and preventive programs planning. PMID:23283053

Socioeconomic inequalities in cardiovascular mortality and the role of childhood socioeconomic conditions and adulthood risk factors: a prospective cohort study with 17-years of follow up

PubMed Central

2012-01-01

Background The mechanisms underlying socioeconomic inequalities in mortality from cardiovascular diseases (CVD) are largely unknown. We studied the contribution of childhood socioeconomic conditions and adulthood risk factors to inequalities in CVD mortality in adulthood. Methods The prospective GLOBE study was carried out in the Netherlands, with baseline data from 1991, and linked with the cause of death register in 2007. At baseline, participants reported on adulthood socioeconomic position (SEP) (own educational level), childhood socioeconomic conditions (occupational level of respondent’s father), and a broad range of adulthood risk factors (health behaviours, material circumstances, psychosocial factors). This present study is based on 5,395 men and 6,306 women, and the data were analysed using Cox regression models and hazard ratios (HR). Results A low adulthood SEP was associated with increased CVD mortality for men (HR 1.84; 95% CI: 1.41-2.39) and women (HR 1.80; 95%CI: 1.04-3.10). Those with poorer childhood socioeconomic conditions were more likely to die from CVD in adulthood, but this reached statistical significance only among men with the poorest childhood socioeconomic circumstances. About half of the investigated adulthood risk factors showed significant associations with CVD mortality among both men and women, namely renting a house, experiencing financial problems, smoking, physical activity and marital status. Alcohol consumption and BMI showed a U-shaped relationship with CVD mortality among women, with the risk being significantly greater for both abstainers and heavy drinkers, and among women who were underweight or obese. Among men, being single or divorced and using sleep/anxiety drugs increased the risk of CVD mortality. In explanatory models, the largest contributor to adulthood CVD inequalities were material conditions for men (42%; 95% CI: −73 to −20) and behavioural factors for women (55%; 95% CI: -191 to −28). Simultaneous adjustment for adulthood risk factors and childhood socioeconomic conditions attenuated the HR for the lowest adulthood SEP to 1.34 (95% CI: 0.99-1.82) for men and 1.19 (95% CI: 0.65-2.15) for women. Conclusions Adulthood material, behavioural and psychosocial factors played a major role in the explanation of adulthood SEP inequalities in CVD mortality. Childhood socioeconomic circumstances made a modest contribution, mainly via their association with adulthood risk factors. Policies and interventions to reduce health inequalities are likely to be most effective when considering the influence of socioeconomic circumstances across the entire life course and in particular, poor material conditions and unhealthy behaviours in adulthood. PMID:23217053

Evaluation of stress intensity factors for bi-material interface cracks using displacement jump methods

NASA Astrophysics Data System (ADS)

Nehar, K. C.; Hachi, B. E.; Cazes, F.; Haboussi, M.

2017-12-01

The aim of the present work is to investigate the numerical modeling of interfacial cracks that may appear at the interface between two isotropic elastic materials. The extended finite element method is employed to analyze brittle and bi-material interfacial fatigue crack growth by computing the mixed mode stress intensity factors (SIF). Three different approaches are introduced to compute the SIFs. In the first one, mixed mode SIF is deduced from the computation of the contour integral as per the classical J-integral method, whereas a displacement method is used to evaluate the SIF by using either one or two displacement jumps located along the crack path in the second and third approaches. The displacement jump method is rather classical for mono-materials, but has to our knowledge not been used up to now for a bi-material. Hence, use of displacement jump for characterizing bi-material cracks constitutes the main contribution of the present study. Several benchmark tests including parametric studies are performed to show the effectiveness of these computational methodologies for SIF considering static and fatigue problems of bi-material structures. It is found that results based on the displacement jump methods are in a very good agreement with those of exact solutions, such as for the J-integral method, but with a larger domain of applicability and a better numerical efficiency (less time consuming and less spurious boundary effect).

Nuclear reference materials to meet the changing needs of the global nuclear community

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

Martin, H.R.; Gradle, C.G.; Narayanan, U.I.

New Brunswick Laboratory (NBL) serves as the US Government`s Certifying Authority for nuclear reference materials and measurement calibration standards. In this role, NBL provides nuclear reference materials certified for chemical and/or isotopic compositions traceable to a nationally accepted, internationally compatible reference base. Emphasis is now changing as to the types of traceable nuclear reference materials needed as operations change within the Department of Energy (DOE) complex and at nuclear facilities around the world. Environmental and waste minimization issues, facilities and materials transitioning from processing to storage modes with corresponding changes in the types of measurements being performed, emphasis on requirementsmore » for characterization of waste materials, difficulties in transporting nuclear materials, and International factors, including International Atomic Energy Agency (IAEA) inspection of excess US nuclear materials, are all contributing influences. During these changing times, ft is critical that traceable reference materials be provided for calibration or validation of the performance of measurement systems. This paper will describe actions taken and planned to meet the changing reference material needs of the global nuclear community.« less

Probabilistic Multi-Factor Interaction Model for Complex Material Behavior

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Abumeri, Galib H.

2008-01-01

The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the launch external tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points, the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation the data used was obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated.

Probabilistic Multi-Factor Interaction Model for Complex Material Behavior

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Abumeri, Galib H.

2008-01-01

The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the launch external tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation, the data used was obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated.

Design Research on Ratio and Proportion Learning by Using Ratio Table and Graph with Oku Timur Context at the 7th Grade

ERIC Educational Resources Information Center

Muttaqin, Haniful; Putri, Ratu Ilma Indra; Somakim

2017-01-01

This research was motivated by several studies which show that students have difficulties in understanding the material ratio, wherein one contributing factor is the lack of ability in proportional reasoning. The purpose of this study is to produce a trajectory of learning to help students develop abilities in comparison reasoning. Solution…

Inequalities in mental health and well-being in a time of austerity: Baseline findings from the Stockton-on-Tees cohort study.

PubMed

Mattheys, K; Bambra, C; Warren, J; Kasim, A; Akhter, N

2016-12-01

Since 2010, the UK has pursued a policy of austerity characterised by public spending cuts and welfare changes. There has been speculation - but little actual research - about the effects of this policy on health inequalities. This paper reports on a case study of local health inequalities in the local authority of Stockton-on-Tees in the North East of England, an area characterised by high spatial and socio-economic inequalities. The paper presents baseline findings from a prospective cohort study of inequalities in mental health and mental wellbeing between the most and least deprived areas of Stockton-on-Tees. This is the first quantitative study to explore local mental health inequalities during the current period of austerity and the first UK study to empirically examine the relative contributions of material, psychosocial and behavioural determinants in explaining the gap. Using a stratified random sampling technique, the data was analysed using multi-level models that explore the gap in mental health and wellbeing between people from the most and least deprived areas of the local authority, and the relative contributions of material, psychosocial and behavioural factors to this gap. The main findings indicate that there is a significant gap in mental health between the two areas, and that material and psychosocial factors appear to underpin this gap. The findings are discussed in relation to the context of the continuing programme of welfare changes and public spending cuts in the UK.

An ultra-low background PMT for liquid xenon detectors

DOE PAGES

Akerib, D. S.; Bai, X.; Bernard, E.; ...

2012-11-15

Results are presented from radioactivity screening of two models of photomultiplier tubes designed for use in current and future liquid xenon experiments. The Hamamatsu 5.6 cm diameter R8778 PMT, used in the LUX dark matter experiment, has yielded a positive detection of four common radioactive isotopes: 238U, 232Th, 40K, and 60Co. Screening of LUX materials has rendered backgrounds from other detector materials subdominant to the R8778 contribution. A prototype Hamamatsu 7.6 cm diameter R11410 MOD PMT has also been screened, with benchmark isotope counts measured at <0.4 238U / <0.3 232Th / < 8.3 40K / 2.0+-0.2 60Co mBq/PMT. This represents a large reduction, equal to a change of xmore » $$\\frac{1}{24}$$ 238U / x $$\\frac{1}{9}$$ 232Th / x $$\\frac{1}{8}$$ 40K per PMT, between R8778 and R11410 MOD, concurrent with a doubling of the photocathode surface area (4.5 cm to 6.4 cm diameter). 60Co measurements are comparable between the PMTs, but can be significantly reduced in future R11410 MOD units through further material selection. Assuming PMT activity equal to the measured 90% upper limits, Monte Carlo estimates indicate that replacement of R8778 PMTs with R11410 MOD PMTs will change LUX PMT electron recoil background contributions by a factor of x $$\\frac{1}{25}$$ after further material selection for 60Co reduction, and nuclear recoil backgrounds by a factor of \\times $$\\frac{1}{36}$$. The strong reduction in backgrounds below the measured R8778 levels makes the R11410 MOD a very competitive technology for use in large-scale liquid xenon detectors.« less

Role of working conditions in the explanation of occupational inequalities in work injury: findings from the national French SUMER survey.

PubMed

Niedhammer, Isabelle; Lesuffleur, Thomas; Labarthe, Géraldine; Chastang, Jean-François

2018-03-12

Social inequalities in work injury have been observed but explanations are still missing. The objectives of this study were to evaluate the contribution of working conditions in the explanation of social inequalities in work injury in a national representative sample of employees. The study was based on the cross-sectional sample of the national French survey SUMER 2010 including 46,962 employees, 26,883 men and 20,079 women. The number of work injuries within the last 12 months was studied as the outcome. Occupation was used as a marker of social position. Psychosocial work factors included various variables related to the classical job strain model, psychological demands, decision latitude, social support, and other understudied variables related to reward, job insecurity, job promotion, esteem, working time and hours and workplace violence. Occupational exposures of chemical, biological, physical and biomechanical nature were also studied. Weighted age-adjusted Poisson regression analyses were performed. Occupational gradients were observed in the exposure of most psychosocial work factors and occupational exposures. Strong occupational differences in work injury were found, blue-collar workers being more likely to have work injury. Chemical, biological, physical and biomechanical exposures contributed to explain the occupational differences in work injury substantially. Noise, thermic constraints, manual materials handling, postural/articular constraints and vibrations had significant contributions. Psychosocial work factors also contributed to explain the differences especially among women. Prevention policies oriented toward chemical, biological, physical, biomechanical and psychosocial work exposures may contribute to reduce the magnitude of occupational differences in work injury.

Interpretation of postmortem forensic toxicology results for injury prevention research.

PubMed

Drummer, Olaf H; Kennedy, Briohny; Bugeja, Lyndal; Ibrahim, Joseph Elias; Ozanne-Smith, Joan

2013-08-01

Forensic toxicological data provides valuable insight into the potential contribution of alcohol and drugs to external-cause deaths. There is a paucity of material that guides injury researchers on the principles that need to be considered when examining the presence and contribution of alcohol and drugs to these deaths. This paper aims to describe and discuss strengths and limitations of postmortem forensic toxicology sample selection, variations in analytical capabilities and data interpretation for injury prevention research. Issues to be considered by injury researchers include: the circumstances surrounding death (including the medical and drug use history of the deceased person); time and relevant historical factors; postmortem changes (including redistribution and instability); laboratory practices; specimens used; drug concentration; and attribution of contribution to death. This paper describes the range of considerations for testing and interpreting postmortem forensic toxicology, particularly when determining impairment or toxicity as possible causal factors in injury deaths. By describing these considerations, this paper has application to decisions about study design and case inclusion in injury prevention research, and to the interpretation of research findings.

Historical Contributions to Vertical Flight at the NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Hodges, William T.; Gorton, Susan A.; Jackson, Karen E.

2016-01-01

The NASA Langley Research Center has had a long and distinguished history in powered lift technology development. This research has formed the foundation of knowledge for the powered lift community worldwide. From aerodynamics to structures, aeromechanics, powered lift, acoustics, materials, stability & control, structural dynamics and human factors, Langley has made significant contributions to the advancement of vertical lift technologies. This research has encompassed basic phenomenological studies through subscale laboratory testing, analytical tool development, applied demonstrations and full scale flight-testing. Since the dedication of Langley in 1920, it has contributed to the understanding, design, analysis, and flight test development of experimental and production V/STOL configurations. This paper will chronicle significant areas of research through the decades from 1920 to 2015 with historical photographs and references.

Thinker, Soldier, Scribe: cross-sectional study of researchers' roles and author order in the Annals of Internal Medicine.

PubMed

Perneger, Thomas V; Poncet, Antoine; Carpentier, Marc; Agoritsas, Thomas; Combescure, Christophe; Gayet-Ageron, Angèle

2017-06-24

How researchers' contributions relate to author order on the byline remains unclear. We sought to identify researchers' contributions associated with author order, and to explore the existence of author profiles. Observational study. Published record. 1139 authors of 119 research articles published in 2015 in the Annals of Internal Medicine . Presence or absence of 10 contributions, reported by each author, published in the journal. On average, first authors reported 7.1 contributions, second authors 5.2, middle authors 4.0, penultimate authors 4.5 and last authors 6.4 (p<0.001). The first author made the greatest contributions to drafting the article, designing the study, analysing and interpreting the data, and providing study materials or patients. The second author contributed to data analysis as well and to drafting the article. The last author was most involved in obtaining the funding, critically revising the article, designing the study and providing support. Factor analysis yielded three author profiles- Thinker (study design, revision of article, obtaining funding), Soldier (providing material or patients, providing administrative and logistical support, collecting data) and Scribe (analysis and interpretation of data, drafting the article, statistical expertise). These profiles do not strictly correspond to byline position. First, second and last authors of research articles made distinct contributions to published research. Three authorship profiles can be used to summarise author contributions. These findings shed light on the organisation of clinical research teams and may help researchers discuss, plan and report authorship in a more transparent way. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Thermal conductivity of 2D nano-structured graphitic materials and their composites with epoxy resins

NASA Astrophysics Data System (ADS)

Mu, Mulan; Wan, Chaoying; McNally, Tony

2017-12-01

The outstanding thermal conductivity (λ) of graphene and its derivatives offers a potential route to enhance the thermal conductivity of epoxy resins. Key challenges still need to be overcome to ensure effective dispersion and distribution of 2D graphitic fillers throughout the epoxy matrix. 2D filler type, morphology, surface chemistry and dimensions are all important factors in determining filler thermal conductivity and de facto the thermal conductivity of the composite material. To achieve significant enhancement in the thermal conductivity of epoxy composites, different strategies are required to minimise phonon scattering at the interface between the nano-filler and epoxy matrix, including chemical functionalisation of the filler surfaces such that interactions between filler and matrix are promoted and interfacial thermal resistance (ITR) reduced. The combination of graphitic fillers with dimensions on different length scales can potentially form an interconnected multi-dimensional filler network and, thus contribute to enhanced thermal conduction. In this review, we describe the relevant properties of different 2D nano-structured graphitic materials and the factors which determine the translation of the intrinsic thermal conductivity of these 2D materials to epoxy resins. The key challenges and perspectives with regard achieving epoxy composites with significantly enhanced thermal conductivity on addition of 2D graphitic materials are presented.

Influence of Reading Material Characteristics on Study Time for Pre-Class Quizzes in a Flipped Classroom

PubMed Central

Hogg, Abigail

2017-01-01

Objective. To examine how instructor-developed reading material relates to pre-class time spent preparing for the readiness assurance process (RAP) in a team-based learning (TBL) course. Methods. Students within pharmacokinetics and physiology were asked to self-report the amount of time spent studying for the RAP. Correlation analysis and multilevel linear regression techniques were used to identify factors within the pre-class reading material that contribute to self-reported study time. Results. On average students spent 3.2 hours preparing for a section of material in the TBL format. The ratio of predicted reading time, based on reading speed and word count, and self-reported study time was greater than 1:3. Self-reported study time was positively correlated with word count, number of tables and figures, and overall page length. For predictors of self-reported study time, topic difficulty and number of figures were negative predictors whereas word count and number of self-assessments were positive predictors. Conclusion. Factors related to reading material are moderate predictors of self-reported student study time for an accountability assessment. A more significant finding is student self-reported study time is much greater than the time predicted by simple word count. PMID:28970604

Influence of Reading Material Characteristics on Study Time for Pre-Class Quizzes in a Flipped Classroom.

PubMed

Persky, Adam M; Hogg, Abigail

2017-08-01

Objective. To examine how instructor-developed reading material relates to pre-class time spent preparing for the readiness assurance process (RAP) in a team-based learning (TBL) course. Methods. Students within pharmacokinetics and physiology were asked to self-report the amount of time spent studying for the RAP. Correlation analysis and multilevel linear regression techniques were used to identify factors within the pre-class reading material that contribute to self-reported study time. Results. On average students spent 3.2 hours preparing for a section of material in the TBL format. The ratio of predicted reading time, based on reading speed and word count, and self-reported study time was greater than 1:3. Self-reported study time was positively correlated with word count, number of tables and figures, and overall page length. For predictors of self-reported study time, topic difficulty and number of figures were negative predictors whereas word count and number of self-assessments were positive predictors. Conclusion. Factors related to reading material are moderate predictors of self-reported student study time for an accountability assessment. A more significant finding is student self-reported study time is much greater than the time predicted by simple word count.

Microbial Keratitis: Could Contact Lens Material Affect Disease Pathogenesis?

PubMed Central

Evans, David J.; Fleiszig, Suzanne M. J.

2012-01-01

Microbial keratitis is a sight-threatening complication associated with contact lenses. The introduction of silicone hydrogel lens materials with increased oxygen transmission to the ocular surface has not significantly altered the incidence of microbial keratitis. These data suggest that alternate, or additional, predisposing factors involving lens wear must be addressed to reduce or eliminate these infections. The contact lens can provide a surface for microbial growth in situ, and can also influence ocular surface homeostasis through effects on the tear fluid and corneal epithelium. Thus, it is intuitive that future contact lens materials could make a significant contribution to preventing microbial keratitis. Design of the “right” material to prevent microbial keratitis requires understanding the effects of current materials on bacterial virulence in the cornea, and on ocular surface innate defenses. Current knowledge in each of these areas will be presented, with a discussion of future directions needed to understand the influence of lens material on the pathogenesis of microbial keratitis. PMID:23266587

[Clothing and heat disorder].

PubMed

Satsumoto, Yayoi

2012-06-01

The influence of the clothing material properties(like water absorbency and rapid dryness, water vapor absorption, water vapor permeability and air permeability) and the design factor of the clothing(like opening condition and fitting of clothing), which contributed to prevent heat disorder, was outlined. WBGT(wet-bulb globe temperature) is used to show a guideline for environmental limitation of activities to prevent heat disorder. As the safety function is more important than thermal comfort for some sportswear and protective clothing with high cover area, clothing itself increases the risk of heat disorder. WBGT is corrected by CAF (clothing adjustment factor) in wearing such kind of protective clothing.

Implant Surface Design Regulates Mesenchymal Stem Cell Differentiation and Maturation

PubMed Central

Boyan, B.D.; Cheng, A.; Olivares-Navarrete, R.; Schwartz, Z.

2016-01-01

Changes in dental implant materials, structural design, and surface properties can all affect biological response. While bulk properties are important for mechanical stability of the implant, surface design ultimately contributes to osseointegration. This article reviews the surface parameters of dental implant materials that contribute to improved cell response and osseointegration. In particular, we focus on how surface design affects mesenchymal cell response and differentiation into the osteoblast lineage. Surface roughness has been largely studied at the microscale, but recent studies have highlighted the importance of hierarchical micron/submicron/nanosurface roughness, as well as surface roughness in combination with surface wettability. Integrins are transmembrane receptors that recognize changes in the surface and mediate downstream signaling pathways. Specifically, the noncanonical Wnt5a pathway has been implicated in osteoblastic differentiation of cells on titanium implant surfaces. However, much remains to be elucidated. Only recently have studies been conducted on the differences in biological response to implants based on sex, age, and clinical factors; these all point toward differences that advocate for patient-specific implant design. Finally, challenges in implant surface characterization must be addressed to optimize and compare data across studies. An understanding of both the science and the biology of the materials is crucial for developing novel dental implant materials and surface modifications for improved osseointegration. PMID:26927483

Inventory simulation tools: Separating nuclide contributions to radiological quantities

NASA Astrophysics Data System (ADS)

Gilbert, Mark R.; Fleming, Michael; Sublet, Jean-Christophe

2017-09-01

The activation response of a material is a primary factor considered when evaluating its suitability for a nuclear application. Various radiological quantities, such as total (becquerel) activity, decay heat, and γ dose, can be readily predicted via inventory simulations, which numerically evolve in time the composition of a material under exposure to neutron irradiation. However, the resulting data sets can be very complex, often necessarily resulting in an over-simplification of the results - most commonly by just considering total response metrics. A number of different techniques for disseminating more completely the vast amount of data output from, in particular, the FISPACT-II inventory code system, including importance diagrams, nuclide maps, and primary knock-on atom (PKA) spectra, have been developed and used in scoping studies to produce database reports for the periodic table of elements. This paper introduces the latest addition to this arsenal - standardised and automated plotting of the time evolution in a radiological quantity for a given material separated by contributions from dominant radionuclides. Examples for relevant materials under predicted fusion reactor conditions, and for bench-marking studies against decay-heat measurements, demonstrate the usefulness and power of these radionuclide-separated activation plots. Note to the reader: the pdf file has been changed on September 22, 2017.

Using a detailed inventory of a large wastewater treatment plant to estimate the relative importance of construction to the overall environmental impacts.

PubMed

Morera, Serni; Corominas, Lluís; Rigola, Miquel; Poch, Manel; Comas, Joaquim

2017-10-01

The aim of this work is to quantify the relative contribution to the overall environmental impact of the construction phase compared to the operational phase for a large conventional activated sludge wastewater treatment plant (WWTP). To estimate these environmental impacts, a systematic procedure was designed to obtain the detailed Life Cycle Inventories (LCI) for civil works and equipment, taking as starting point the construction project budget and the list of equipment installed at the Girona WWTP, which are the most reliable information sources of materials and resources used during the construction phase. A detailed inventory is conducted by including 45 materials for civil works and 1,240 devices for the equipment. For most of the impact categories and different life spans of the WWTP, the contribution of the construction phase to the overall burden is higher than 5% and, especially for metal depletion, the impact of construction reaches 63%. When comparing to the WWTP inventories available in Ecoinvent the share of construction obtained in this work is about 3 times smaller for climate change and twice higher for metal depletion. Concrete and reinforcing steel are the materials with the highest contribution to the civil works phase and motors, pumps and mobile and transport equipment are also key equipment to consider during life cycle inventories of WWTPs. Additional robust inventories for similar WWTP can leverage this work by applying the factors (kg of materials and energy per m 3 of treated water) and guidance provided. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quasi-Phasematched Nonlinear Optics: Materials and Devices

DTIC Science & Technology

2012-02-29

effects all contribute, and that the group velocity dispersion in the vicinity of the pump wavelength and are important factors influencing the breadth...for the physics underlying χ(2) SC generation, so the work was purely empirical, but still resulted in octave-class SC and envelop locking with...specific goals, e.g soliton self-frequency shift, SC generation, etc. emerged, and could then be optimized with the numerical simulation tool

Material Logistic Support of the Hospital Ships

DTIC Science & Technology

1986-12-01

Codeine Sulfate Tablets 6505-00-132-6904 Isoniazid Tablets 6505-00-165-6545 Cephalexin Capsules 6505-00-165-6575 Rifampin Capsules 6505-00-400-2054...35 4. CONSUMPTION RATE FOR MEDICAL CONSUMABLE ITEM FOR SPECIFIC CONDITION UNDER SCENARIO A 38 5. CONTRIBUTION FACTOR FOR BISACODYL TABLETS FOR SCENARIO...probability that patient condition 249 will require Bisacodyl. If the probability was twenty percent, then the amount of Bisacodyl needed would be two tablets

Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces.

PubMed

Boys, Alexander J; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J; Estroff, Lara A

2017-09-01

Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors.

Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces

PubMed Central

Boys, Alexander J.; McCorry, Mary Clare; Rodeo, Scott; Bonassar, Lawrence J.; Estroff, Lara A.

2017-01-01

Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors. PMID:29333332

The effect of forging history on the strength and microstructure of TDNiCr /Ni-20Cr-2ThO2/

NASA Technical Reports Server (NTRS)

Filippi, A. M.

1975-01-01

Forging variables were evaluated to determine their influence on the elevated temperature strength and microstructure of TDNiCr. Grain size was the principal microstructural feature related to elevated temperature strength and was controlled primarily by the thermomechanical variables of forging temperature and final annealing condition. Tests at 1366 K revealed a factor of eight increase in tensile strength as grain size increased from 1 to 150 microns, while stress-rupture strength improved by three to five times as grain size increased from 15 to 150 microns. Forged material of grain size greater than or equal to about 150 microns displayed a level of elevated temperature strength comparable to that of optimized TDNiCr sheet. The presence of a preponderance of small twins and a strong preferred orientation may have also been factors contributing to the excellent high temperature strength of large grain forged material.

A Unique Computational Algorithm to Simulate Probabilistic Multi-Factor Interaction Model Complex Material Point Behavior

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Abumeri, Galib H.

2010-01-01

The Multi-Factor Interaction Model (MFIM) is used to evaluate the divot weight (foam weight ejected) from the launch external tanks. The multi-factor has sufficient degrees of freedom to evaluate a large number of factors that may contribute to the divot ejection. It also accommodates all interactions by its product form. Each factor has an exponent that satisfies only two points--the initial and final points. The exponent describes a monotonic path from the initial condition to the final. The exponent values are selected so that the described path makes sense in the absence of experimental data. In the present investigation, the data used was obtained by testing simulated specimens in launching conditions. Results show that the MFIM is an effective method of describing the divot weight ejected under the conditions investigated.

[Review of lime carbon sink.

PubMed

Liu, Li Li; Ling, Jiang Hua; Tie, Li; Wang, Jiao Yue; Bing, Long Fei; Xi, Feng Ming

2018-01-01

Under the background of "missing carbon sink" mystery and carbon capture and storage (CCS) technology development, this paper summarized the lime material flow process carbon sink from the lime carbonation principles, impact factors, and lime utilization categories in chemical industry, metallurgy industry, construction industry, and lime kiln ash treatment. The results showed that the lime carbonation rate coefficients were mainly impacted by materials and ambient conditions; the lime carbon sink was mainly in chemical, metallurgy, and construction industries; and current researches focused on the mechanisms and impact factors for carbonation, but their carbon sequestration calculation methods had not been proposed. Therefore, future research should focus on following aspects: to establish a complete system of lime carbon sequestration accounting method in view of material flow; to calculate lime carbon sequestration in both China and the world and explain their offset proportion of CO 2 emission from lime industrial process; to analyze the contribution of lime carbon sequestration to missing carbon sink for clarifying part of missing carbon sinks; to promote the development of carbon capture and storage technology and provide some scientific bases for China's international negotiations on climate change.

Understanding a Nonlinear Causal Relationship Between Rewards and Physicians' Contributions in Online Health Care Communities: Longitudinal Study.

PubMed

Wang, Jying-Nan; Chiu, Ya-Ling; Yu, Haiyan; Hsu, Yuan-Teng

2017-12-21

The online health care community is not just a place for the public to share physician reviews or medical knowledge, but also a physician-patient communication platform. The medical resources of developing countries are relatively inadequate, and the online health care community is a potential solution to alleviate the phenomenon of long hospital queues and the lack of medical resources in rural areas. However, the success of the online health care community depends on online contributions by physicians. The aim of this study is to examine the effect of incentive mechanisms on physician's online contribution behavior in the online health community. We addressed the following questions: (1) from which specialty area are physicians more likely to participate in online health care community activities, (2) what are the factors affecting physician online contributions, and (3) do incentive mechanisms, including psychological and material rewards, result in differences of physician online contributions? We designed a longitudinal study involving a data sample in three waves. All data were collected from the Good Doctor website, which is the largest online health care community in China. We first used descriptive statistics to investigate the physician online contribution behavior in its entirety. Then multiple linear and quadratic regression models were applied to verify the causal relationship between rewards and physician online contribution. Our sample included 40,300 physicians from 3607 different hospitals, 10 different major specialty areas, and 31 different provinces or municipalities. Based on the multiple quadratic regression model, we found that the coefficients of the control variables, past physician online contributions, doctor review rating, clinic title, hospital level, and city level, were .415, .189, -.099, -.106, and -.143, respectively. For the psychological (or material) rewards, the standardized coefficient of the main effect was 0.261 (or 0.688) and the standardized coefficient of the quadratic effect was -0.015 (or -0.049). All estimates were statistically significant (P<.001). Physicians with more past physician online contribution, with higher review ratings, coming from lower level clinics, not coming from tertiary hospitals, and not coming from big cities were more willing to participate in online health care community activities. To promote physician online contribution, it is necessary to establish an appropriate incentive mechanism including psychological and material rewards. Finally, our findings suggest two guidelines for designing a useful incentive mechanism to facilitate physician online contribution. First, material reward is more useful than psychological reward. Second, as indicated by the concave-down-increasing causal relationship between rewards and physician online contribution, although an appropriate reward is effective in encouraging willingness on the part of physicians to contribute to the online health care community, the effect of additional rewards is limited. ©Jying-Nan Wang, Ya-Ling Chiu, Haiyan Yu, Yuan-Teng Hsu. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 21.12.2017.

Understanding a Nonlinear Causal Relationship Between Rewards and Physicians’ Contributions in Online Health Care Communities: Longitudinal Study

PubMed Central

2017-01-01

Background The online health care community is not just a place for the public to share physician reviews or medical knowledge, but also a physician-patient communication platform. The medical resources of developing countries are relatively inadequate, and the online health care community is a potential solution to alleviate the phenomenon of long hospital queues and the lack of medical resources in rural areas. However, the success of the online health care community depends on online contributions by physicians. Objective The aim of this study is to examine the effect of incentive mechanisms on physician’s online contribution behavior in the online health community. We addressed the following questions: (1) from which specialty area are physicians more likely to participate in online health care community activities, (2) what are the factors affecting physician online contributions, and (3) do incentive mechanisms, including psychological and material rewards, result in differences of physician online contributions? Methods We designed a longitudinal study involving a data sample in three waves. All data were collected from the Good Doctor website, which is the largest online health care community in China. We first used descriptive statistics to investigate the physician online contribution behavior in its entirety. Then multiple linear and quadratic regression models were applied to verify the causal relationship between rewards and physician online contribution. Results Our sample included 40,300 physicians from 3607 different hospitals, 10 different major specialty areas, and 31 different provinces or municipalities. Based on the multiple quadratic regression model, we found that the coefficients of the control variables, past physician online contributions, doctor review rating, clinic title, hospital level, and city level, were .415, .189, –.099, –.106, and –.143, respectively. For the psychological (or material) rewards, the standardized coefficient of the main effect was 0.261 (or 0.688) and the standardized coefficient of the quadratic effect was –0.015 (or –0.049). All estimates were statistically significant (P<.001). Conclusions Physicians with more past physician online contribution, with higher review ratings, coming from lower level clinics, not coming from tertiary hospitals, and not coming from big cities were more willing to participate in online health care community activities. To promote physician online contribution, it is necessary to establish an appropriate incentive mechanism including psychological and material rewards. Finally, our findings suggest two guidelines for designing a useful incentive mechanism to facilitate physician online contribution. First, material reward is more useful than psychological reward. Second, as indicated by the concave-down-increasing causal relationship between rewards and physician online contribution, although an appropriate reward is effective in encouraging willingness on the part of physicians to contribute to the online health care community, the effect of additional rewards is limited. PMID:29269344

Radio frequency and capacitive sensors for dielectric characterization of low-conductivity media

NASA Astrophysics Data System (ADS)

Sheldon, Robert T.

Low-conductivity media are found in a vast number of applications, for example as electrical insulation or as the matrix polymer in high strength-to-weight ratio structural composites. In some applications, these materials are subjected to extreme environmental, thermal, and mechanical conditions that can affect the material's desired performance. In a more general sense, a medium may be comprised of one or more layers with unknown material properties that may affect the desired performance of the entire structure. It is often, therefore, of great import to be able to characterize the material properties of these media for the purpose of estimating their future performance in a certain application. Low-conductivity media, or dielectrics, are poor electrical conductors and permit electromagnetic waves and static electric fields to pass through with minimal attenuation. The amount of electrical energy that may be stored (and lost) in these fields depends directly upon the material property, permittivity, which is generally complex, frequency-dependent and has a measurable effect on sensors designed to characterize dielectric media. In this work, two different types of dielectric sensors: radio frequency resonant antennas and lower-frequency (<1 MHz) capacitive sensors, are designed for permittivity characterization in their respective frequency regimes. In the first part of this work, the capability of characterizing multilayer dielectric structures is studied using a patch antenna, a type of antenna that is primarily designed for data communications in the microwave bands but has application in the field of nondestructive evaluation as well. Each configuration of a patch antenna has a single lowest resonant (dominant mode) frequency that is dependent upon the antenna's substrate material and geometry as well as the permittivity and geometry of exterior materials. Here, an extant forward model is validated using well-characterized microwave samples and a new method of resonant frequency and quality factor determination from measured data is presented. Excellent agreement between calculated and measured values of sensor resonant frequency was obtained for the samples studied. Agreement between calculated and measured quality factor was good in some cases but incurred the particular challenge of accurately quantifying multiple contributions to loss from the sensor structure itself, which at times dominates the contribution due to the sample material. Two later chapters describe the development of capacitive sensors to quantify the low-frequency changes in material permittivity due to environmental aging mechanisms. One embodiment involves the application of coplanar concentric interdigital electrode sensors for the purpose of investigating polymer-matrix degradation in glass-fiber composites due to isothermal aging. Samples of bismaleimide-matrix glass-fiber composites were aged at several high temperatures to induce thermal degradation and capacitive sensors were used to measure the sensor capacitance and dissipation factor, parameters that are directly proportional to the real and imaginary components of complex permittivity, respectively. It was shown that real permittivity and dissipation factor decreased with increasing aging temperature, a trend that was common to both interdigital sensor measurements and standard parallel plate electrode measurements. The second piece of work involves the development of cylindrical interdigital electrode sensors to characterize complex permittivity changes in wire insulation due to aging-related degradation. The sensor was proven effective in detecting changes in irradiated nuclear power plant wiring insulation and in aircraft wiring insulation due to liquid chemical immersion. In all three cases, the results indicate a clear correlation of measured capacitance and dissipation factor with increased degradation.

Nurses’experiences of perceived support and their contributing factors: A qualitative content analysis

PubMed Central

Sodeify, Roghieh; Vanaki, Zohreh; Mohammadi, Eesa

2013-01-01

Background: Following professional standards is the main concern of all managers in organizations. The functions of nurses are essential for both productivity and improving health organizations. In human resources management, supporting nursing profession is of ultimate importance. However, nurses’ experiences of perceived support, which are affected by various factors in workplace, have not been clearly explained yet. Thus, this study aimed to explain nurses’ experiences of perceived support and their contributing factors. Materials and Methods: This study is a qualitative research in which 12 nurses were selected through purposive sampling among nurses in university hospitals affiliated to University of Medical Sciences, Urmia, Iran, during 2011-2012. Data collection was conducted through deep interviews with semi-structural questions. All interviews were first recorded and then transcribed. Finally, data were analyzed through conventional content analysis. Results: The four main themes indicated that nurses experienced their workplace as non-supportive. Themes such as poor organizational climate, low social dignity, poor work conditions, and managers’ ignorance to individual and professional values were considered as inhibitory factors to support. Conclusion: Nursing managers can promote nurses’ positive support perceptions through recognizing inhibitory factors and applying fair solutions and take benefits of their positive consequences including high efficacy, self-esteem, and organizational commitment to promote the quality of care. PMID:23983753

Odour emissions from poultry litter - A review litter properties, odour formation and odorant emissions from porous materials.

PubMed

Dunlop, Mark W; Blackall, Patrick J; Stuetz, Richard M

2016-07-15

Odour emissions from meat chicken sheds can at times cause odour impacts on surrounding communities. Litter is seen as the primary source of this odour. Formation and emission of odour from meat chicken litter during the grow-out period are influenced by various factors such as litter conditions, the environment, microbial activity, properties of the odorous gases and management practices. Odour emissions vary spatially and temporally. This variability has made it challenging to understand how specific litter conditions contribute to odour emissions from the litter and production sheds. Existing knowledge on odorants, odour formation mechanisms and emission processes that contribute to odour emissions from litter are reviewed. Litter moisture content and water thermodynamics (i.e. water activity, Aw) are also examined as factors that contribute to microbial odour formation, physical litter conditions and the exchange of individual odorant gases at the air-water interface. Substantial opportunities exist for future research on litter conditions and litter formation mechanisms and how these contribute to odour emissions. Closing this knowledge gap will improve management strategies that intercept and interfere with odour formation and emission processes leading to an overall reduction in the potential to cause community impacts. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Mapping individuals' earthquake preparedness in China

NASA Astrophysics Data System (ADS)

Wu, Guochun; Han, Ziqiang; Xu, Weijin; Gong, Yue

2018-05-01

Disaster preparedness is critical for reducing potential impact. This paper contributes to current knowledge of disaster preparedness using representative national sample data from China, which faces high earthquake risks in many areas of the country. The adoption of earthquake preparedness activities by the general public, including five indicators of material preparedness and five indicators of awareness preparedness, were surveyed and 3245 respondents from all 31 provinces of Mainland China participated in the survey. Linear regression models and logit regression models were used to analyze the effects of potential influencing factors. Overall, the preparedness levels are not satisfied, with a material preparation score of 3.02 (1-5), and awareness preparation score of 2.79 (1-5), nationally. Meanwhile, residents from western China, which has higher earthquake risk, have higher degrees of preparedness. The concern for disaster risk reduction (DRR) and the concern for building safety and participation in public affairs are consistent positive predictors of both material and awareness preparedness. The demographic and socioeconomic variables' effects, such as gender, age, education, income, urban/rural division, and building size, vary according to different preparedness activities. Finally, the paper concludes with a discussion of the theoretical contribution and potential implementation.

Analysis of fire deaths in Poland and influence of smoke toxicity.

PubMed

Giebułtowicz, Joanna; Rużycka, Monika; Wroczyński, Piotr; Purser, David A; Stec, Anna A

2017-08-01

Dwelling fires have changed over the years because building contents and the materials used in then have changed. They all contribute to an ever-growing diversity of chemical species found in fires, many of them highly toxic. These arise largely from the changing nature of materials in interior finishes and furniture, with an increasing content of synthetic materials containing higher levels of nitrogen, halogen and phosphorus additives. While there is still a belief that carbon monoxide is the major lethal toxic agent in fires, the hydrogen cyanide and acid gases released from these additives are now well-recognised as major contributory causes of incapacitation, morbidity and mortality in domestic fires. Data for the total number of 263 fire death cases in the Mazowieckie region (mainly Warsaw area) of Poland between 2003-2011 for dwellings fires were obtained from pathologists, forensic toxicologists, fire fighters and analysed. Factors contributing to the death such as the findings of the full post mortem examination (age, sex, health status, burns), the toxicological analysis (carbon monoxide, alcohol etc.), and a thorough investigation of the scene (fire conditions, fuel, etc.) were taken into account and are summarised. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of flooring on environmental stressors: a study of three flooring materials in a hospital.

PubMed

Harris, Debra D

2015-01-01

Three flooring materials, terrazzo, rubber, and carpet tile, in patient unit corridors were compared for absorption of sound, comfort, light reflectance, employee perceptions and preferences, and patient satisfaction. Environmental stressors, such as noise and ergonomic factors, effect healthcare workers and patients, contributing to increased fatigue, anxiety and stress, decreased productivity, and patient safety and satisfaction. A longitudinal comparative cohort study comparing three types of flooring assessed sound levels, healthcare worker responses, and patient Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) ratings over 42 weeks. A linear mixed model analysis was conducted to determine significant differences between the means for participant responses and objective sound meter data during all three phases of the study. A significant difference was found for sound levels between flooring type for equivalent continuous sound levels. Carpet tile performed better for sound attenuation by absorption, reducing sound levels 3.14 dBA. Preferences for flooring materials changed over the course of the study. The HCAHPS ratings aligned with the sound meter data showing that patients perceived the noise levels to be lower with carpet tiles, improving patient satisfaction ratings. Perceptions for healthcare staff and patients were aligned with the sound meter data. Carpet tile provides sound absorption that affects sound levels and influences occupant's perceptions of environmental factors that contribute to the quality of the indoor environment. Flooring that provides comfort underfoot, easy cleanability, and sound absorption influence healthcare worker job satisfaction and patient satisfaction with their patient experience. © The Author(s) 2015.

Work-related injuries among union drywall carpenters in Washington State, 1989-2008.

PubMed

Schoenfisch, Ashley L; Lipscomb, Hester; Marshall, Steve; Cameron, Wilfred; Richardson, David; Casteel, Carri

2013-10-01

Drywall installers are at high-risk of work-related injury. Comprehensive descriptive epidemiology of injuries among drywall installers, particularly over time, is lacking. We identified worker-hours and reported and accepted workers' compensation (WC) claims for a 20-year (1989-2008) cohort of 24,830 Washington State union carpenters. Stratified by predominant type of work (drywall installation, other carpentry), work-related injury rates were examined over calendar time and by worker characteristics. Expert interviews provided contextual details. Drywall installers' injury rates, higher than those of other carpenters, declined substantially over this period by 73.6%. Common injury mechanisms were struck by/against, overexertion and falls. Drywall material was considered a contributing factor in 19.7% of injuries. One-third of these drywall material-related injuries resulted in paid lost time, compared to 19.4% of injuries from other sources. Rates of injury were particularly high among workers with 2 to <4 years in the union. Notable declines over time in rates of overexertion injury in which drywall material was a contributing factor were still observed after controlling for secular temporal trends. Experts highlighted changes over the past 20 years that improved both work safety and, in some cases, production. Declines in drywall installers' injury rates over time likely reflect, in part, enhanced workplace safety, including efforts to reduce overexertion hazards associated with handling drywall. Continued injury prevention efforts are needed, particularly for less tenured workers. Given the potential for under-reporting to WC, additional sources of health outcomes data may provide a more complete picture of workers' health. Copyright © 2013 Wiley Periodicals, Inc.

Novel Functionalized Carbon Nanotube Supercapacitor Materials: Contribution to the Supercapacitor TIF

DTIC Science & Technology

2014-08-01

Novel functionalized carbon nanotube supercapacitor materials Contribution to the supercapacitor TIF Trisha Huber...Novel functionalized carbon nanotube supercapacitor materials Contribution to the supercapacitor TIF Trisha Huber...presented as a log-log plot. As illustrated, supercapacitors offer performance intermediate between batteries and capacitors in that they exhibit higher

SU-E-T-101: Determination and Comparison of Correction Factors Obtained for TLDs in Small Field Lung Heterogenous Phantom Using Acuros XB and EGSnrc

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

Soh, R; Lee, J; Harianto, F

Purpose: To determine and compare the correction factors obtained for TLDs in 2 × 2cm{sup 2} small field in lung heterogenous phantom using Acuros XB (AXB) and EGSnrc. Methods: This study will simulate the correction factors due to the perturbation of TLD-100 chips (Harshaw/Thermoscientific, 3 × 3 × 0.9mm{sup 3}, 2.64g/cm{sup 3}) in small field lung medium for Stereotactic Body Radiation Therapy (SBRT). A physical lung phantom was simulated by a 14cm thick composite cork phantom (0.27g/cm{sup 3}, HU:-743 ± 11) sandwiched between 4cm thick Plastic Water (CIRS,Norfolk). Composite cork has been shown to be a good lung substitute materialmore » for dosimetric studies. 6MV photon beam from Varian Clinac iX (Varian Medical Systems, Palo Alto, CA) with field size 2 × 2cm{sup 2} was simulated. Depth dose profiles were obtained from the Eclipse treatment planning system Acuros XB (AXB) and independently from DOSxyznrc, EGSnrc. Correction factors was calculated by the ratio of unperturbed to perturbed dose. Since AXB has limitations in simulating actual material compositions, EGSnrc will also simulate the AXB-based material composition for comparison to the actual lung phantom. Results: TLD-100, with its finite size and relatively high density, causes significant perturbation in 2 × 2cm{sup 2} small field in a low lung density phantom. Correction factors calculated by both EGSnrc and AXB was found to be as low as 0.9. It is expected that the correction factor obtained by EGSnrc wlll be more accurate as it is able to simulate the actual phantom material compositions. AXB have a limited material library, therefore it only approximates the composition of TLD, Composite cork and Plastic water, contributing to uncertainties in TLD correction factors. Conclusion: It is expected that the correction factors obtained by EGSnrc will be more accurate. Studies will be done to investigate the correction factors for higher energies where perturbation may be more pronounced.« less

Source/process apportionment of major and trace elements in sinking particles in the Sargasso sea

NASA Astrophysics Data System (ADS)

Huang, S.; Conte, M. H.

2009-01-01

Elemental composition of the particle flux at the Oceanic Flux Program (OFP) time-series site off Bermuda was measured from January 2002 to March 2005. Eighteen elements (Mg, Al, Si, P, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba and Pb) in sediment trap material from 500, 1500 and 3200 m depths were quantified using fusion-HR-ICPMS. Positive Matrix Factorization (PMF) was used to elucidate sources, elemental associations and processes that affect geochemical behavior in the water column. Results provide evidence for intense elemental cycling between the sinking flux material and the dissolved and suspended pools within mesopelagic and bathypelagic waters. Biological processing and remineralization rapidly deplete the sinking flux material in organic matter and associated elements (N, P, Cd, Zn) between 500 and 1500 m depth. Suspended particle aggregation, authigenic mineral precipitation, and chemical scavenging enriches the flux material in lithogenic minerals, barite and redox sensitive elements (Mn, Co, V, Fe). A large increase in the flux of lithogenic elements is observed with depth and confirms that the northeast Sargasso is a significant sink for advected continental materials, likely supplied via Gulf Stream circulation. PMF resolved major sources that contribute to sinking flux at all depths (carbonate, high-Mg carbonate, opal, organic matter, lithogenic material, and barite) as well as additional depth-specific elemental associations that contribute about half of the compositional variability in the flux. PMF solutions indicate close geochemical associations of barite-opal, Cd-P, Zn-Co, Zn-Pb and redox sensitive elements in the sinking flux material at 500 m depth. Major reorganizations of element associations occur as labile carrier phases break down and elements redistribute among new carrier phases deeper in the water column. Factor scores show strong covariation and similar temporal phasing among the three trap depths and indicate a tight coupling in particle flux compositional variability throughout the water column. Seasonality in flux composition is primarily driven by dilution of the lithogenic component with freshly-produced biogenic material during the late winter primary production maximum. Temporal trends in scores reveal subtle non-seasonal changes in flux composition occurring on month long timescales. This non-seasonal variability may be driven by changes in the biogeochemical properties of intermediate water masses that pass through the region and which affect rates of chemical scavenging and/or aggregation within the water column.

A Study of the "toss Factor" in the Impact Testing of Cermets by the Izod Pendulum Test

NASA Technical Reports Server (NTRS)

Probst, H B; Mchenry, Howard T

1957-01-01

The test method presented shows that the "toss energy" contributed by the apparatus for brittle materials is negligible. The total toss energy is considered to consist of two components. (a) recovered stored elastic energy and (b) kinetic energy contributed directly by the apparatus. The results were verified by high-speed motion pictures of the test in operation. From these photographs, velocities of tossed specimens were obtained and toss energy computed. In addition, impact energies of some titanium carbide base cermets and high-temperature alloys, as measured by the low-capacity Izod pendulum test, compare well with impact energies measured by the NACA drop test.

Weathering of radiocaesium contamination on urban streets, walls and roofs.

PubMed

Andersson, K G; Roed, J; Fogh, C L

2002-01-01

Recent investigations in Russia have emphasised the significance of dose contributions from contamination on urban streets and roof pavings, and, typically to a lesser extent, walls in the urban environment. The crucial factor determining the magnitude of these contributions is the retention of the contamination by the different types of urban surface. Since the Chernobyl accident, a series of long-term field studies has been carried out on urban streets, walls and roofs, to examine the weathering processes of 137Cs on the various surface types. The derived time-functions are applied to estimate resultant long-term doses to inhabitants of an urban centre. The paper highlights the effect on caesium retention of surface material characteristics.

A highly compliant serpentine shaped polyimide interconnect for front-end strain relief in chronic neural implants.

PubMed

Sankar, Viswanath; Sanchez, Justin C; McCumiskey, Edward; Brown, Nagid; Taylor, Curtis R; Ehlert, Gregory J; Sodano, Henry A; Nishida, Toshikazu

2013-01-01

While the signal quality of recording neural electrodes is observed to degrade over time, the degradation mechanisms are complex and less easily observable. Recording microelectrodes failures are attributed to different biological factors such as tissue encapsulation, immune response, and disruption of blood-brain barrier (BBB) and non-biological factors such as strain due to micromotion, insulation delamination, corrosion, and surface roughness on the recording site (1-4). Strain due to brain micromotion is considered to be one of the important abiotic factors contributing to the failure of the neural implants. To reduce the forces exerted by the electrode on the brain, a high compliance 2D serpentine shaped electrode cable was designed, simulated, and measured using polyimide as the substrate material. Serpentine electrode cables were fabricated using MEMS microfabrication techniques, and the prototypes were subjected to load tests to experimentally measure the compliance. The compliance of the serpentine cable was numerically modeled and quantitatively measured to be up to 10 times higher than the compliance of a straight cable of same dimensions and material.

A Highly Compliant Serpentine Shaped Polyimide Interconnect for Front-End Strain Relief in Chronic Neural Implants

PubMed Central

Sankar, Viswanath; Sanchez, Justin C.; McCumiskey, Edward; Brown, Nagid; Taylor, Curtis R.; Ehlert, Gregory J.; Sodano, Henry A.; Nishida, Toshikazu

2013-01-01

While the signal quality of recording neural electrodes is observed to degrade over time, the degradation mechanisms are complex and less easily observable. Recording microelectrodes failures are attributed to different biological factors such as tissue encapsulation, immune response, and disruption of blood-brain barrier (BBB) and non-biological factors such as strain due to micromotion, insulation delamination, corrosion, and surface roughness on the recording site (1–4). Strain due to brain micromotion is considered to be one of the important abiotic factors contributing to the failure of the neural implants. To reduce the forces exerted by the electrode on the brain, a high compliance 2D serpentine shaped electrode cable was designed, simulated, and measured using polyimide as the substrate material. Serpentine electrode cables were fabricated using MEMS microfabrication techniques, and the prototypes were subjected to load tests to experimentally measure the compliance. The compliance of the serpentine cable was numerically modeled and quantitatively measured to be up to 10 times higher than the compliance of a straight cable of same dimensions and material. PMID:24062716

Improving comfort of shoe sole through experiments based on CAD-FEM modeling.

PubMed

Franciosa, Pasquale; Gerbino, Salvatore; Lanzotti, Antonio; Silvestri, Luca

2013-01-01

It was reported that next to style, comfort is the second key aspect in purchasing footwear. One of the most important components of footwear is the shoe sole, whose design is based on many factors such as foot shape/size, perceived comfort and materials. The present paper focuses on the parametric analysis of a shoe sole to improve the perceived comfort. The sensitivity of geometric and material design factors on comfort degree was investigated by combining real experimental tests and CAD-FEM simulations. The correlation between perceived comfort and physical responses, such as plantar pressures, was estimated by conducting real tests. Four different conditions were analyzed: subjects wearing three commercially available shoes and in a barefoot condition. For each condition, subjects expressed their perceived comfort score. By adopting plantar sensors, the plantar pressures were also monitored. Once given such a correlation, a parametric FEM model of the footwear was developed. In order to better simulate contact at the plantar surface, a detailed FEM model of the foot was also generated from CT scan images. Lastly, a fractional factorial design array was applied to study the sensitivity of different sets of design factors on comfort degree. The findings of this research showed that the sole thickness and its material highly influence perceived comfort. In particular, softer materials and thicker soles contribute to increasing the degree of comfort. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Influence of Psychosocial Factors and Habitual Behavior in Temporomandibular Disorder–Related Symptoms in a Working Population in Japan

PubMed Central

Nishiyama, Akira; Kino, Koji; Sugisaki, Masashi; Tsukagoshi, Kaori

2012-01-01

Background: The symptoms of temporomandibular disorders (TMD) are directly influenced by numerous factors, and it is thought that additional factors exert indirect influences. However, the relationships between TMD-related symptoms (TRS) and these contributing factors are largely unknown. Thus, the goal of the present study was to investigate influences on TRS in a working population by determining the prevalence of TRS, analyzing contributing factors, and determining their relative influences on TRS. Materials and Methods: The study subjects were 2203 adults who worked for a single company. Subjects completed a questionnaire assessing TRS, psychosocial factors (stress, anxiety, depressed mood, and chronic fatigue), tooth-contacting habit, and sleep bruxism-related morning symptoms, using a 5-point numeric rating scale. Our analysis proceeded in 2 phases. First, all variables of the descriptor were divided into parts by using an exploratory factor analysis. Second, this factorial structure was verified by using a confirmatory factor analysis with structural equation modeling. Results: Of 2203 employees, 362 reported experiencing TRS (16.4%). Structural equation modeling generated a final model with a goodness of fit index of 0.991, an adjusted goodness of fit index of 0.984, and a root mean square error of approximately 0.021. These indices indicate a strong structural model. The standardized path coefficients for “habitual behavioral factors and TRS,” “psychosocial factors and habitual behavioral factors,” “psychosocial factors and TRS,” and “gender and habitual behavior factors” were 0.48, 0.38, 0.14, and 0.18, respectively. Conclusions: Habitual behavioral factors exert a stronger effect on TRS than do psychosocial factors. PMID:23346261

Factor Influencing Creative Industries Development in Kenjeran Surabaya

NASA Astrophysics Data System (ADS)

Siswanto, V. K.; Santoso, E. B.

2017-07-01

Indonesia needs to improve the competitiveness of local products to optimize its contribution to the ASEAN Economic Community (AEC) for the welfare of the population. This can be done by improving the development of creative industries. Kenjeran Sub District is one of the coastal villages in the city of Surabaya, which has a large number of poor people. The potential of the creative industries is still not visible in efforts to increase public welfare. Therefore, it is necessary to investigate the factors that influence the development of creative industries in Kenjeran. This study using in-depth interview were analysed using content analysis and Cartesian diagram to determine the important factors that affect the development of creative industries in Sub district of Kenjeran. By using five respondents from the government shows that the factors that have a high level of importance and advantages are low among other regulatory factors of raw materials, import and export, extortion, and administrative procedures.

Everyday attention and lecture retention: the effects of time, fidgeting, and mind wandering.

PubMed

Farley, James; Risko, Evan F; Kingstone, Alan

2013-01-01

We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behavior. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-min lecture video, and at regular 5-min intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behavior was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual's attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention.

Everyday attention and lecture retention: the effects of time, fidgeting, and mind wandering

PubMed Central

Farley, James; Risko, Evan F.; Kingstone, Alan

2013-01-01

We have all had our thoughts wander from the immediate task at hand. The emerging embodied cognition literature emphasizes the role that the body plays in human thought, and raises the possibility that changes in attentional focus may be associated with changes in body behavior. Recent research has found that when individuals view a lecture, mind wandering increases as a function of time. In the present study we asked whether this decline in attention during lecture viewing was associated with fidgeting. Participants were filmed while they watched a 40-min lecture video, and at regular 5-min intervals provided ratings of their attentiveness. Following the lecture, participant's memory for the material was assessed. Fidgeting behavior was coded from video recordings of each session. Results indicated that attention to, and retention of, lecture material declined as a function of time on task. Critically, and as predicted, fidgeting also increased with time on task. We also found that the relation between fidgeting and retention was significant even when the role of attention was factored into the equation, suggesting that fidgeting makes a unique contribution to retention of lecture material over and above that contributed by an individual's attention. We propose a novel non-attentional stress-based account of fidgeting and how this impacts retention for lecture material over and above changes in levels in mind wandering vis-a-vis changes in attention. PMID:24065933

[The impact of social and hygienic lifestyle factors on health status of students].

PubMed

Sakharova, O B; Kiku, P F; Gorborukova, T V

2012-01-01

The complex estimation of the impact of socio-hygienic lifestyle factors on the health of students has been performed. In the work the data of sociological analysis (questionnaire), the methods of multivariate statistics (correlation, regression analysis, method of correlation pleiades by P. V. Terentiev) were used. Among the analyzed components the average monthly income was found to make the greatest contribution of the health state and physical capacity of the studied contingent of students. The influence of this factor is most pronounced in a group of students with an average wealth. The quality of nutrition and the mode of life depend on the level of material well-being of students. Students with a deficiency or excess body weight are more susceptible to the effects of such lifestyle factors such as nutrition, physical activity, bad habits and prosperity.

Recycling of lower continental crust through foundering of cumulates from contaminated mafic intrusions

NASA Technical Reports Server (NTRS)

Arndt, Nicholas T.; Goldstein, Steven L.

1988-01-01

A mechanism is presented for recycling of lower continental material back into the mantle. Picritic magmas, possible parental to volumious continental volcanics such as the Karoo and Deccan, became trapped at the Moho, where they interacted with and become contaminated by lower crustal materials. Upon crystallization, the magmas differentiated into lower ultramafic cumulate zones and upper gabbroic-anorthositic zones. The ultramafic cumulates are denser than underlying mantle and sink, carrying lower crustal components as trapped liquid, as xenoliths or rafts, and as constituents of cumulate minerals. This model provides a potentially significant crust-mantle differentiation mechanism, and may also represent a contributing factor in crustal recycling, possibly important in producing some OIB reservoirs.

Variations in embodied energy and carbon emission intensities of construction materials

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

Wan Omar, Wan-Mohd-Sabki; School of Environmental Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis; Doh, Jeung-Hwan, E-mail: j.doh@griffith.edu.au

2014-11-15

Identification of parameter variation allows us to conduct more detailed life cycle assessment (LCA) of energy and carbon emission material over their lifecycle. Previous research studies have demonstrated that hybrid LCA (HLCA) can generally overcome the problems of incompleteness and accuracy of embodied energy (EE) and carbon (EC) emission assessment. Unfortunately, the current interpretation and quantification procedure has not been extensively and empirically studied in a qualitative manner, especially in hybridising between the process LCA and I-O LCA. To determine this weakness, this study empirically demonstrates the changes in EE and EC intensities caused by variations to key parameters inmore » material production. Using Australia and Malaysia as a case study, the results are compared with previous hybrid models to identify key parameters and issues. The parameters considered in this study are technological changes, energy tariffs, primary energy factors, disaggregation constant, emission factors, and material price fluctuation. It was found that changes in technological efficiency, energy tariffs and material prices caused significant variations in the model. Finally, the comparison of hybrid models revealed that non-energy intensive materials greatly influence the variations due to high indirect energy and carbon emission in upstream boundary of material production, and as such, any decision related to these materials should be considered carefully. - Highlights: • We investigate the EE and EC intensity variation in Australia and Malaysia. • The influences of parameter variations on hybrid LCA model were evaluated. • Key significant contribution to the EE and EC intensity variation were identified. • High indirect EE and EC content caused significant variation in hybrid LCA models. • Non-energy intensive material caused variation between hybrid LCA models.« less

Potency of Fish Collagen as a Scaffold for Regenerative Medicine

PubMed Central

Yamamoto, Kohei; Yanagiguchi, Kajiro

2014-01-01

Cells, growth factors, and scaffold are the crucial factors for tissue engineering. Recently, scaffolds consisting of natural polymers, such as collagen and gelatin, bioabsorbable synthetic polymers, such as polylactic acid and polyglycolic acid, and inorganic materials, such as hydroxyapatite, as well as composite materials have been rapidly developed. In particular, collagen is the most promising material for tissue engineering due to its biocompatibility and biodegradability. Collagen contains specific cell adhesion domains, including the arginine-glycine-aspartic acid (RGD) motif. After the integrin receptor on the cell surface binds to the RGD motif on the collagen molecule, cell adhesion is actively induced. This interaction contributes to the promotion of cell growth and differentiation and the regulation of various cell functions. However, it is difficult to use a pure collagen scaffold as a tissue engineering material due to its low mechanical strength. In order to make up for this disadvantage, collagen scaffolds are often modified using a cross-linker, such as gamma irradiation and carbodiimide. Taking into account the possibility of zoonosis, a variety of recent reports have been documented using fish collagen scaffolds. We herein review the potency of fish collagen scaffolds as well as associated problems to be addressed for use in regenerative medicine. PMID:24982861

Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system

NASA Astrophysics Data System (ADS)

El Kanawati, W.; Perot, B.; Carasco, C.; Eleon, C.; Valkovic, V.; Sudac, D.; Obhodas, J.

2011-10-01

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the 3H(d,n) 4H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs.

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

Morgan, K.T.; Monticello, T.M.

The nasal passages of laboratory animals and man are complex, and lesions induced in the delicate nasal lining by inhaled air pollutants vary considerably in location and nature. The distribution of nasal lesions is generally a consequence of regional deposition of the inhaled material, local tissue susceptibility, or a combination of these factors. Nasal uptake and regional deposition are are influenced by numerous factors including the physical and chemical properties of the inhaled material, such as water solubility and reactivity; airborne concentration and length of exposure; the presence of other air contaminants such as particulate matter; nasal metabolism, and bloodmore » and mucus flow. For certain highly water-soluble or reactive gases, nasal airflow patterns play a major role in determining lesion distribution. Studies of nasal airflow in rats and monkeys, using casting and molding techniques combined with a water-dye model, indicate that nasal airflow patterns are responsible for characteristic differences in the distribution of nasal lesions induced by formaldehyde in these species. Local tissue susceptibility is also a complex issue that may be a consequence of many factors, including physiologic and metabolic characteristics of the diverse cell populations that comprise each of the major epithelial types lining the airways. Identification of the principal factors that influence the distribution and nature of nasal lesions is important when attempting the difficult process of determining potential human risks using data derived from laboratory animals. Toxicologic pathologists can contribute to this process by carefully identifying the site and nature of nasal lesions induced by inhaled materials. 61 references.« less

Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

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

Chen, Q.; Farmer, D. K.; Rizzo, L. V.

Real-time mass spectra of non-refractory component of submicron aerosol particles were recorded in a tropical rainforest in the central Amazon basin during the wet season of 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic components accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. Ammonium was present in sufficient quantities to halfway neutralize sulfate. In this acidic, isoprene-dominated, low-NOx environment the high-resolution mass spectra as well as mass closures with ion chromatography measurements did not provide evidence for significant contributions of organosulfate species, at least atmore » concentrations above uncertainty levels. Positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the variance of the signal intensities of the organic constituents: a factor HOA having a hydrocarbon-like signature and identified as regional emissions of primary organic material, a factor OOA-1 associated with fresh production of secondary organic material by a mechanism of BVOC oxidation followed by gas-to-particle conversion, a factor OOA-2 consistent with reactive uptake of isoprene oxidation products, especially epoxydiols by acidic particles, and a factor OOA-3 associated with long range transport and atmospheric aging. The OOA-1, -2, and -3 factors had progressively more oxidized signatures. Diameter-resolved mass spectral markers also suggested enhanced reactive uptake of isoprene oxidation products to the accumulation mode for the OOA-2 factor, and such size partitioning can be indicative of in-cloud process. The campaign-average factor loadings were in a ratio of 1.1:1.0 for the OOA-1 compared to the OOA-2 pathway, suggesting the comparable importance of gas-phase compared to particle-phase (including cloud waters) production pathways of secondary organic material during the study period.« less

Inequity in Health Care Financing in Iran: Progressive or Regressive Mechanism?

PubMed Central

Rad, Enayatollah Homaie; Khodaparast, Marzie

2016-01-01

Objective: Having progressive health finance mechanism is very important to decrease inequity in health systems. Revenue collection is one of the aspects of health care financing. In this study, taxation system and health insurance contribution of Iranians were assessed. Materials and Methods: Data of 2012 household expenditures survey were used in this study, and payments of the families for health insurances and tax payments were extracted from the study. Kakwani index was calculated for assessing the progressivity of these payments. At the end, a model was designed to find the effective factors. Results: We found that taxation mechanism was progressive, but insurance contribution mechanism was very regressive. The portion of people living in urban regions was higher in the payments of insurance and tax. Less educated families had lower contribution in health insurance and families with more aging persons paid more for health insurance. Conclusion: Policy makers must pay more attention to the health insurance contribution and change the laws in favour of the poor. PMID:27551174

Sediment sources in a small agricultural catchment: A composite fingerprinting approach based on the selection of potential sources

NASA Astrophysics Data System (ADS)

Zhou, Huiping; Chang, Weina; Zhang, Longjiang

2016-08-01

Fingerprinting techniques have been widely used as a reasonable and reliable means for investigating sediment sources, especially in relatively large catchments in which there are significant differences in surface materials. However, the discrimination power of fingerprint properties for small catchments, in which the surface materials are relatively homogeneous and human interference is marked, may be affected by fragmentary or confused source information. Using fingerprinting techniques can be difficult, and there is still a need for further studies to verify the effectiveness of such techniques in these small catchments. A composite fingerprinting approach was used in this study to investigate the main sources of sediment output, as well as their relative contributions, from a small catchment (30 km2) with high levels of farming and mining activities. The impact of the selection of different potential sediment sources on the derivation of composite fingerprints and its discrimination power were also investigated by comparing the results from different combinations of potential source types. The initial source types and several samples that could cause confusion were adjusted. These adjustments improved the discrimination power of the composite fingerprints. The results showed that the composite fingerprinting approach used in this study had a discriminatory efficiency of 89.2% for different sediment sources and that the model had a mean goodness of fit of 0.90. Cultivated lands were the main sediment source. The sediment contribution of the studied cultivated lands ranged from 39.9% to 87.8%, with a mean of 76.6%, for multiple deposited sediment samples. The mean contribution of woodlands was 21.7%. Overall, the sediment contribution from mining and road areas was relatively low. The selection of potential sources is an important factor in the application of fingerprinting techniques and warrants more attention in future studies, as is the case with other uncertainty factors.

Keith's MAGIC: Cloning and the Cell Cycle.

PubMed

Wells, D N

2013-10-01

Abstract Professor Keith Campbell's critical contribution to the discovery that a somatic cell from an adult animal can be fully reprogrammed by oocyte factors to form a cloned individual following nuclear transfer (NT)(Wilmut et al., 1997 ) overturned a dogma concerning the reversibility of cell fate that many scientists had considered to be biologically impossible. This seminal experiment proved the totipotency of adult somatic nuclei and finally confirmed that adult cells could differentiate without irreversible changes to the genetic material.

Foundations for teaching surgeons to address the contributions of systems to operating room team conflict.

PubMed

Rogers, David A; Lingard, Lorelei; Boehler, Margaret L; Espin, Sherry; Schindler, Nancy; Klingensmith, Mary; Mellinger, John D

2013-09-01

Prior research has shown that surgeons who effectively manage operating room conflict engage in a problem-solving stage devoted to modifying systems that contribute to team conflict. The purpose of this study was to clarify how systems contributed to operating room team conflict and clarify what surgeons do to modify them. Focus groups of circulating nurses and surgeons were conducted at 5 academic medical centers. Narratives describing the contributions of systems to operating room conflict and behaviors used by surgeons to address those systems were analyzed using the constant comparative approach associated with a constructivist grounded theory approach. Operating room team conflict was affected by 4 systems-related factors: team features, procedural-specific staff training, equipment management systems, and the administrative leadership itself. Effective systems problem solving included advocating for change based on patient safety concerns. The results of this study provide clarity about how systems contribute to operating room conflict and what surgeons can do to effectively modify these systems. This information is foundational material for a conflict management educational program for surgeons. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of environmental and material factors on the response of nanocomposite foam impact sensors

NASA Astrophysics Data System (ADS)

Bird, Evan; Merrell, Jake; Rosquist, Parker; Martineau, Adin; Bowden, Anton; Seeley, Matthew; Fullwood, David

2018-05-01

Nanocomposite foam (NCF) is a multifunctional material that can be used to measure impact. Interactions between the flexible polymer matrix and conductive particles dispersed throughout it produce a voltage signal under dynamic strain, which correlates to the magnitude of impact. Though promising in applications requiring both impact sensing and energy absorption, NCF’s voltage response has been observed to suffer from significant signal drift. This paper investigates several causes of variance in the response of NCF sensors to consistent impacts. These effects can be classified into three general types: recoverable transient effects (such as those relating to viscoelasticity or capacitive charging), environmental drift (due to humidity and temperature), and permanent signal decay from material degradation. The motivation for the study arises from various potential repeat-impact applications where periodic recalibration of the sensor would be difficult (such as a gait-tracking insole in use for a marathon event). A cyclic drop testing machine was used to apply consistent impacts to NCF, and drift resulting from each factor (in ranges typical of an insole environment) was experimentally isolated. Models representing each factor’s contribution to signal drift are presented. Of the factors investigated, humidity and temperature caused the most significant drift, with permanent material degradation accounting for only minor decay in voltage response. Transient effects were also observed, with a characteristic ‘warm-up’ (or ‘charging’) time required for the NCF to achieve steady-state; this phenomenon, and the related ‘recovery’ time for the material to return to its original state, were determined. The resultant data can be leveraged to implement a correction algorithm or other drift-compensating method to retain an NCF sensor’s accuracy in both long and short data collection scenarios.

Identifying Sources of Volatile Organic Compounds and Aldehydes in a High Performance Building

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

Ortiz, Anna C.; Russell, Marion; Lee, Wen-Yee

The developers of the Paharpur Business Center (PBC) and Software Technology Incubator Park in New Delhi, India offer an environmentally sustainable building with a strong emphasis on energy conservation, waste minimization and superior indoor air quality (IAQ). To achieve the IAQ goal, the building utilizes a series of air cleaning technologies for treating the air entering the building. These technologies include an initial water wash followed by ultraviolet light treatment and biolfiltration using a greenhouse located on the roof and numerous plants distributed throughout the building. Even with the extensive treatment of makeup air and room air in the PBC,more » a recent study found that the concentrations of common volatile organic compounds and aldehydes appear to rise incrementally as the air passes through the building from the supply to the exhaust. This finding highlights the need to consider the minimization of chemical sources in buildings in combination with the use of advanced air cleaning technologies when seeking to achieve superior IAQ. The goal of this project was to identify potential source materials for indoor chemicals in the PBC. Samples of building materials, including wood paneling (polished and unpolished), drywall, and plastic from a hydroponic drum that was part of the air cleaning system, were collected from the building for testing. All materials were collected from the PBC building and shipped to the Lawrence Berkeley National Laboratory (LBNL) for testing. The materials were pre-conditioned for two different time periods before measuring material and chemical specific emission factors for a range of VOCs and Aldehydes. Of the six materials tested, we found that the highest emitter of formaldehyde was new plywood paneling. Although polish and paint contribute to some VOC emissions, the main influence of the polish was in altering the capacity of the surface to accumulate formaldehyde. Neither the new nor aged polish contributed significantly to formaldehyde emissions. The VOC emission stream (excluding formaldehyde) was composed of up to 18 different chemicals and the total VOC emissions ranged in magnitude from 7 mu g/m2/h (old wood with old polish) to>500 mu g/m2/h (painted drywall). The formaldehyde emissions from drywall and old wood with either new or old polish were ~;;15 mu g/m2/h while the new wood material emitted>100 mu g/m2/h. However, when the projected surface area of each material in the building was considered, the new wood, old wood and painted drywall material all contributed substantially to the indoor formaldehyde loading while the coatings contributed primarily to the VOCs.« less

Equipment failures and their contribution to industrial incidents and accidents in the manufacturing industry.

PubMed

Bourassa, Dominic; Gauthier, François; Abdul-Nour, Georges

2016-01-01

Accidental events in manufacturing industries can be caused by many factors, including work methods, lack of training, equipment design, maintenance and reliability. This study is aimed at determining the contribution of failures of commonly used industrial equipment, such as machines, tools and material handling equipment, to the chain of causality of industrial accidents and incidents. Based on a case study which aimed at the analysis of an existing pulp and paper company's accident database, this paper examines the number, type and gravity of the failures involved in these events and their causes. Results from this study show that equipment failures had a major effect on the number and severity of accidents accounted for in the database: 272 out of 773 accidental events were related to equipment failure, where 13 of them had direct human consequences. Failures that contributed directly or indirectly to these events are analyzed.

Molecular dynamics simulation on adsorption of pyrene-polyethylene onto ultrathin single-walled carbon nanotube

NASA Astrophysics Data System (ADS)

Cai, Lu; Lv, Wenzhen; Zhu, Hong; Xu, Qun

2016-07-01

The mechanism of the adsorption of pyrene-polyethylene (Py-PE) onto ultrathin single-walled carbon nanotube (SWNT) was studied by using all-atom molecular dynamics (MD) simulations. We found that solvent polarity and pyrene group are two critical factors in the Py-PE decoration on ultrathin SWNT. Combined MD simulations with free energy calculations, our results indicate that larger solvent polarity can decrease the contribution of conformation entropy, but contributes little to the interaction energy, moreover, larger SWNT diameter can decrease the contribution of conformation entropy but lead to the increasing of the interaction energy. In polar organic solvent (N, N-Dimethylacetamide), the pyrene group plays a key role in the adsorption of Py-PE onto ultrathin SWNT, not only facilitates the spontaneous adsorption of Py-PE onto ultrathin SWNT, but also helps to form compact structure between themselves in the final adsorption states. While in aqueous solution, pyrene group no longer works as an anchor, but still affects a lot to the final adsorption conformation. Our present work provides detailed theoretical clue to understand the noncovalent interaction between aromatic segment appended polymer and ultrathin SWNT, and helps to explore the potential application of ultrathin SWNT in the fields of hybrid material, biomedical and electronic materials.

The effects of proton radiation on the prothrombin and partial thromboplastin times of irradiated ferrets

PubMed Central

Krigsfeld, Gabriel S.; Sanzari, Jenine K.; Kennedy, Ann R.

2013-01-01

Purpose To determine whether proton radiation affects coagulation. Material and methods Ferrets were exposed to solar particle event-like proton radiation at doses of 0, 25, 100, or 200 centigray (cGy), and dose rates of 50 cGy/minute (high dose rate or HDR) or 50 cGy/hour (low dose rate or LDR). Plasma was isolated from blood collected prior to radiation exposure and at 3–7 h post-radiation. Prothrombin time (PT) assays and activated partial thromboplastin time (aPTT) assays were performed as were mixing studies to determine the coagulation factors involved. Results HDR and LDR exposure led to statistically significant increases in PT values. It was determined that the HDR-induced increase in PT was due to Factor VII, while Factors II, V, and VII contributed to the LDR-induced increase in PT values. Only acute LDR exposure caused an increase in aPTT values, which remained elevated for 48 h post-irradiation (which was the latest time assayed in these studies). Mixing studies revealed that Factor IX contributed to the increased aPTT values. A majority of the animals exposed at the LDR had an International Normalized Ratio approaching or surpassing 2.0. Conclusions PT/aPTT assays resulted in increased clotting times due to different coagulation factors, indicating potential radiation-induced coagulopathy. PMID:22221163

Characterization of Atmospheric Pressure Plasma Torch and the Surface Interaction for Material Removal

NASA Astrophysics Data System (ADS)

McWilliams, Anthony Joseph

An atmospheric pressure plasma torch has been developed and characterized for removal of organic based coatings. The focus of the Strategic Environmental Research & Development Program (SERDP) project WP-1762, that funded the bulk of this dissertation work, is removal of paint from US Navy vessels. The goal is to develop a novel technology for coating removal that is capable of reducing the amount of environmental waste produced during the commonly used grit blasting process. The atmospheric pressure air plasma torch was identified as having the capacity to remove the paint systems while using only compressed air and electricity as a media-less removal system with drastically reduced waste generation. Any improvements to the existing technology need to be based on scientific knowledge and thus the plasma removal mechanisms or material warranted investigation. The removal of material does not show a strong relation to the plasma parameters of power, frequency, and gas flow, nor is there a strong relation to the presences of inorganic fillers impeding or altering the removal rates. The underlying removal mechanisms also do not show a strong correlation to the rotational temperature of the plasma but do show a strong correlation to the optical emission intensity. Primarily, the emission from atomic oxygen and molecular nitrogen were identified significant contributors and were investigated further. The plasma feed gas was then varied from the nitrogen and oxygen ratio present in ambient air to pure nitrogen to identify the effect of oxygen on the removal mechanism. From these experiments it was concluded that the oxygen present in air does contribute to the overall removal mechanism; however, it is not the sole contributing factor with the other major factor being nitrogen.

Differential stimulation of neurotrophin release by the biocompatible nano-material (carbon nanotube) in primary cultured neurons.

PubMed

Kim, Yun Gi; Kim, Jong Wan; Pyeon, Hee Jang; Hyun, Jung Keun; Hwang, Ji-Young; Choi, Seong-Jun; Lee, Ja-Yeon; Deák, Ferenc; Kim, Hae-Won; Lee, Young Il

2014-01-01

In order to develop novel, effective therapies for central nervous system regeneration, it is essential to better understand the role of neurotrophic factors and to design, accordingly, better artificial scaffolds to support both neurite outgrowth and synapse formation. Both nerve growth factor and brain-derived neurotrophic factor are major factors in neural survival, development, synaptogenesis, and synaptic connectivity of primary cultured neurons. As a prime candidate coating material for such neural cultures, carbon nanotubes offer unique structural, mechanical, and electrical properties. In this study, carbon nanotubes coated glass-coverslips were used as the matrix of a primary neural culture system used to investigate the effects of carbon nanotubes on neurite outgrowth and nerve growth factor/brain-derived neurotrophic factor release and expression. For these purposes, we performed comparative analyses of primary cultured neurons on carbon nanotubes coated, non-coated, and Matrigel-coated coverslips. The morphological findings showed definite carbon nanotubes effects on the neurite outgrowths and synaptogenic figures in both cortical and hippocampal neurons when compared with the non-coated negative control. Although the carbon nanotubes did not change neurotrophin expression levels, it stimulated brain-derived neurotrophic factor release into the media from both types of neurons. Accordingly, we suggest a different mechanism of action between carbon nanotubes and Matrigel in relation to the specific neurotrophic factors. Since carbon nanotubes supply long-term extracellular molecular cues for the survival and neurite outgrowths of cultured neurons, the results from this study will contribute to an understanding of carbon nanotubes biological effects and provide new insight into their role in the secretion of neurotrophic factors.

The policies-inequality feedback and health: the case of globalisation.

PubMed

De Vogli, R; Gimeno, D; Mistry, R

2009-09-01

Major research contributions aimed at explaining the association between economic inequality and health have concentrated on the plausibility of the material deprivation and psychosocial factors pathways. However, little work has analysed the reciprocal associations between public policies and inequality and their effect on health. A conceptual framework was first proposed explaining how the public policies-inequality feedback can influence health outcomes via material deprivation and psychosocial factors. Then, a critical review of the literature was conducted and an analysis of the health effects of the globalisation-inequality feedback as a case study. Different bodies of evidence seem to give support to the hypothesis of a public policies-inequality feedback influencing health-related outcomes. This seems to be particularly true when considering globalisation policies. Since the widespread adoption of the so-called "Washington Consensus", economic inequalities have sharply increased worldwide. The rise in inequality has, in turn, further consolidated the adoption of these policies through an increasing "democratic deficit". The reciprocal effects of globalisation and inequality have produced adverse health outcomes between and within societies through both material deprivation and psychosocial stress. Public policies and economic inequality are inextricably interrelated and can affect health through multiple, indirect, reciprocal pathways.

Summer 2006 war on Lebanon: a lesson in community resilience.

PubMed

Nuwayhid, Iman; Zurayk, Huda; Yamout, Rouham; Cortas, Chadi S

2011-01-01

The internally displaced persons (IDPs) during the July 2006 war in Lebanon exhibited a high level of community resilience, affirmed by relief agencies and public health professionals. Data from personal observations, interviews, meetings and published material were used to examine factors contributing to this resilience. Findings suggested that community resilience is a process rather than an outcome. The sense of a collective identity, prior experience with wars and social support networks have contributed to building up IDP's resilience over time, while community cohesiveness, adequate public health interventions, social solidarity and a connected political leadership helped to sustain it during and shortly after the war. This paper examines implications for public health professionals and argues for a paradigm shift in disaster relief practice.

TDNiCr (ni-20Cr-2ThO2) forging studies

NASA Technical Reports Server (NTRS)

Filippi, A. M.

1974-01-01

Elevated temperature tensile and stress rupture properties were evaluated for forged TDNiCr (Ni-20Cr-2ThO2) and related to thermomechanical history and microstructure. Forging temperature and final annealed condition had pronounced influences on grain size which, in turn, was related to high temperature strength. Tensile strength improved by a factor of 8 as grain size changed from 1 to 150 microns. Stress-rupture strength was improved by a factor of 3 to 5 by a grain size increase from 10 to 1000 microns. Some contributions to the elevated temperature strength of very large grain material may also occur from the development of a strong texture and a preponderance of small twins. Other conditions promoting the improvement of high temperature strength were: an increase of total reduction, forging which continued the metal deformation inherent in the starting material, a low forging speed, and prior deformation by extrusion. The mechanical properties of optimally forged TDNiCr compared favorably to those of high strength sheet developed for space shuttle application.

Analysis of Factors Influencing Measurement Accuracy of Al Alloy Tensile Test Results

NASA Astrophysics Data System (ADS)

Podgornik, Bojan; Žužek, Borut; Sedlaček, Marko; Kevorkijan, Varužan; Hostej, Boris

2016-02-01

In order to properly use materials in design, a complete understanding of and information on their mechanical properties, such as yield and ultimate tensile strength must be obtained. Furthermore, as the design of automotive parts is constantly pushed toward higher limits, excessive measuring uncertainty can lead to unexpected premature failure of the component, thus requiring reliable determination of material properties with low uncertainty. The aim of the present work was to evaluate the effect of different metrology factors, including the number of tested samples, specimens machining and surface quality, specimens input diameter, type of testing and human error on the tensile test results and measurement uncertainty when performed on 2xxx series Al alloy. Results show that the most significant contribution to measurement uncertainty comes from the number of samples tested, which can even exceed 1 %. Furthermore, moving from experimental laboratory conditions to very intense industrial environment further amplifies measurement uncertainty, where even if using automated systems human error cannot be neglected.

Smoking Cessation and Socioeconomic Status: An Update of Existing Evidence from a National Evaluation of English Stop Smoking Services

PubMed Central

Hiscock, Rosemary; Dobbie, Fiona; Bauld, Linda

2015-01-01

Smokers from lower socioeconomic groups are less likely to be successful in stopping smoking than more affluent smokers, even after accessing cessation programmes. Data were analysed from 3057 clients of nine services. Routine monitoring data were expanded with CO validated smoking status at 52-week follow-up. Backwards logistic regression modelling was used to consider which factors were most important in explaining the relationship between SES and quitting. The odds ratio of stopping smoking among more affluent clients, compared with more disadvantaged clients, after taking into account design variables only, was 1.85 (95% CI 1.44 to 2.37) which declined to 1.44 (1.11 to 1.87) when all controls were included. The factors that explained more than 10% of the decline in the odds ratio were age, proportion of friends and family who smoked, nicotine dependence, and taking varenicline. A range of factors contribute to lower cessation rates for disadvantaged smokers. Some of these can be modified by improved smoking cessation service provision, but others require contributions from wider efforts to improve material, human, and social capital. PMID:26273602

[Biology of gastrointestinal nematodes of ruminants].

PubMed

Manfredi, M T

2006-09-01

The development and survival of free-living stages of gastro-intestinal nematodes of small ruminants are influenced by several abiotic and biotic factors. Within the abiotic factors, most important are the environmental temperature and humidity. They regulate the development of larvae from eggs dispersed on the pasture by the animals faeces. Each parasite species that infect ruminants requires a different time to development, depending on temperature and humidity. Among trichostrongylids, Ostertagia, Teladorsagia and Nematodirus show a strong adaptation to low temperatures. Nematodirus larvae are able to survive to winter inside the egg shell. Temperature and humidity influence the distribution and survival of larvae on pasture. The larval third stage can migrate from faeces to pasture vegetation and they accumulate at the basis of vegetation where stay during the day or in the soil to avoid the desiccation. The forage species affects the migration of larvae on herbage too. Many biological factors contribute to disperse the larvae on the pasture. Dung burying beetles, coprophagous beetles and earthworms can greatly reduce the larvae of some trichostrongylids on pasture. They contribute to the spread of the faecal material on the pasture and allow the larval death as a consequence of drying.

Type A Accident Investigation Board report on the January 17, 1996, electrical accident with injury in Technical Area 21 Tritium Science and Fabrication Facility Los Alamos National Laboratory. Final report

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

NONE

1996-04-01

An electrical accident was investigated in which a crafts person received serious injuries as a result of coming into contact with a 13.2 kilovolt (kV) electrical cable in the basement of Building 209 in Technical Area 21 (TA-21-209) in the Tritium Science and Fabrication Facility (TSFF) at Los Alamos National Laboratory (LANL). In conducting its investigation, the Accident Investigation Board used various analytical techniques, including events and causal factor analysis, barrier analysis, change analysis, fault tree analysis, materials analysis, and root cause analysis. The board inspected the accident site, reviewed events surrounding the accident, conducted extensive interviews and document reviews,more » and performed causation analyses to determine the factors that contributed to the accident, including any management system deficiencies. Relevant management systems and factors that could have contributed to the accident were evaluated in accordance with the guiding principles of safety management identified by the Secretary of Energy in an October 1994 letter to the Defense Nuclear Facilities Safety Board and subsequently to Congress.« less

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

PubMed

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

Elasticity Solution of an Adhesively Bonded Cover Plate of Various Geometries

NASA Technical Reports Server (NTRS)

Aksel, G. N.; Erdogan, F.

1985-01-01

The plane strain of adhesively bonded structures consisting of two different isotropic adherends is considered. By expressing the x-y components of the displacements in terms of Fourier integrals and using the corresponding boundary and continuity conditions, the integral equations for the general problem are obtained and solved numerically by applying Gauss-Chebyshev integration scheme. The shear and the normal stresses in the adhesive are calculated for various geometries and material properties for a stiffened plate under uniaxial tension. Numerical results involving the stress intensity factors and the strain energy release rate are presented. The closed-form expressions for the Fredholm kernels are provided to obtain the solution for an arbitrary geometry and material properties. For the general geometry, the contribution of the normal stress is quite significant, while for symmetric geometries, the shear stress is dominant, the normal stress vanishes if the adherends are of the same material and the same thickness.

Generalised syntheses of ordered mesoporous oxides: the atrane route

NASA Astrophysics Data System (ADS)

Cabrera, Saúl; El Haskouri, Jamal; Guillem, Carmen; Latorre, Julio; Beltrán-Porter, Aurelio; Beltrán-Porter, Daniel; Marcos, M. Dolores; Amorós *, Pedro

2000-06-01

A new simple and versatile technique to obtain mesoporous oxides is presented. While implying surfactant-assisted formation of mesostructured intermediates, the original chemical contribution of this approach lies in the use of atrane complexes as precursors. Without prejudice to their inherent unstability in aqueous solution, the atranes show a marked inertness towards hydrolysis. Bringing kinetic factors into play, it becomes possible to control the processes involved in the formation of the surfactant-inorganic phase composite micelles, which constitute the elemental building blocks of the mesostructures. Independent of the starting compositional complexity, both the mesostructured intermediates and the final mesoporous materials are chemically homogeneous. The final ordered mesoporous materials are thermally stable and show unimodal porosity, as well as homogeneous microstructure and texture. Examples of materials synthesised on account of the versatility of this new method, including siliceous, non siliceous and mixed oxides, are presented and discussed.

Simulation of ceramic materials relevant for nuclear waste management: Case of La1-xEuxPO4 solid solution

NASA Astrophysics Data System (ADS)

Kowalski, Piotr M.; Ji, Yaqi; Li, Yan; Arinicheva, Yulia; Beridze, George; Neumeier, Stefan; Bukaemskiy, Andrey; Bosbach, Dirk

2017-02-01

Using powerful computational resources and state-of-the-art methods of computational chemistry we contribute to the research on novel nuclear waste forms by providing atomic scale description of processes that govern the structural incorporation and the interactions of radionuclides in host materials. Here we present various results of combined computational and experimental studies on La1-xEuxPO4 monazite-type solid solution. We discuss the performance of DFT + U method with the Hubbard U parameter value derived ab initio, and the derivation of various structural, thermodynamic and radiation-damage related properties. We show a correlation between the cation displacement probabilities and the solubility data, indicating that the binding of cations is the driving factor behind both processes. The combined atomistic modeling and experimental studies result in a superior characterization of the investigated material.

PMR Extended Shelf Life Technology Given 2000 R and D 100 Award

NASA Technical Reports Server (NTRS)

Meador, Michael A.

2001-01-01

An approach developed at the NASA Glenn Research Center for extending the shelf life of PMR polyimide solutions and prepregs received an R&D 100 Award this year. PMR polyimides, in particular PMR-15, have become attractive materials for a variety of aerospace applications because of their outstanding high-temperature stability and performance. PMR-15 can be used in components with exposures to temperatures as high as 290 C, which leads to substantial reductions in weight, as much as 30 percent over metal components. PMR-15 composites are used widely in aerospace applications ranging from ducts and external components in aircraft engines to an engine access door for the Space Shuttle Main Engine. A major barrier to more widespread use of these materials is high component costs. Recent efforts at Glenn have addressed the various factors that contribute to these costs in an attempt to more fully utilize these lightweight, high-temperature materials.

Investigation of Machine-ability of Inconel 800 in EDM with Coated Electrode

NASA Astrophysics Data System (ADS)

Karunakaran, K.; Chandrasekaran, M.

2017-03-01

The Inconel 800 is a high temperature application alloy which is classified as a nickel based super alloy. It has wide scope in aerospace engineering, gas Turbine etc. The machine-ability studies were found limited on this material. Hence This research focuses on machine-ability studies on EDM of Inconel 800 with Silver Coated Electrolyte Copper Electrode. The purpose of coating on electrode is to reduce tool wear. The factors pulse on Time, Pulse off Time and Peck Current were considered to observe the responses of surface roughness, material removal rate, tool wear rate. Taguchi Full Factorial Design is employed for Design the experiment. Some specific findings were reported and the percentage of contribution of each parameter was furnished

Imprints of the ejecta-companion interaction in Type Ia supernovae: main-sequence, subgiant, and red giant companions

NASA Astrophysics Data System (ADS)

Boehner, P.; Plewa, T.; Langer, N.

2017-02-01

We study supernova ejecta-companion interactions in a sample of realistic semidetached binary systems representative of Type Ia supernova progenitor binaries in a single-degenerate scenario. We model the interaction process with the help of a high-resolution hydrodynamic code assuming cylindrical symmetry. We find that the ejecta hole has a half-opening angle of 40-50° with the density by a factor of 2-4 lower, in good agreement with the previous studies. Quantitative differences from the past results in the amounts and kinematics of the stripped companion material and levels of contamination of the companion with the ejecta material can be explained by different model assumptions and effects due to numerical diffusion. We analyse and, for the first time, provide simulation-based estimates of the amounts and of the thermal characteristics of the shock-heated material responsible for producing a prompt, soft X-ray emission. Besides the shocked ejecta material, considered in the original model by Kasen, we also account for the stripped, shock-heated envelope material of stellar companions, which we predict partially contributes to the prompt emission. The amount of the energy deposited in the envelope is comparable to the energy stored in the ejecta. The total energy budget available for the prompt emission is by a factor of about 2-4 smaller than originally predicted by Kasen. Although the shocked envelope has a higher characteristic temperature than the shocked ejecta, the temperature estimates of the shocked material are in good agreement with the Kasen's model. The hottest shocked plasma is produced in the subgiant companion case.

Airflow, gas deposition, and lesion distribution in the nasal passages.

PubMed Central

Morgan, K T; Monticello, T M

1990-01-01

The nasal passages of laboratory animals and man are complex, and lesions induced in the delicate nasal lining by inhaled air pollutants vary considerably in location and nature. The distribution of nasal lesions is generally a consequence of regional deposition of the inhaled material, local tissue susceptibility, or a combination of these factors. Nasal uptake and regional deposition are are influenced by numerous factors including the physical and chemical properties of the inhaled material, such as water solubility and reactivity; airborne concentration and length of exposure; the presence of other air contaminants such as particulate matter; nasal metabolism, and blood and mucus flow. For certain highly water-soluble or reactive gases, nasal airflow patterns play a major role in determining lesion distribution. Studies of nasal airflow in rats and monkeys, using casting and molding techniques combined with a water-dye model, indicate that nasal airflow patterns are responsible for characteristic differences in the distribution of nasal lesions induced by formaldehyde in these species. Local tissue susceptibility is also a complex issue that may be a consequence of many factors, including physiologic and metabolic characteristics of the diverse cell populations that comprise each of the major epithelial types lining the airways. Identification of the principal factors that influence the distribution and nature of nasal lesions is important when attempting the difficult process of determining potential human risks using data derived from laboratory animals. Toxicologic pathologists can contribute to this process by carefully identifying the site and nature of nasal lesions induced by inhaled materials. Images FIGURE 4. FIGURE 6. FIGURE 7. PMID:2200663

Utilization of maternal health-care services by tribal women in Kerala

PubMed Central

Jose, Jinu Annie; Sarkar, Sonali; Kumar, S. Ganesh; Kar, Sitanshu Sekhar

2014-01-01

Background: The coverage of maternal care services among the tribal women in Kerala is better as compared to other states in India. Aim: This study was done to identify the factors contributing to better coverage of maternal care services among the tribal women in Kerala and to study the reasons for remaining differences that exists in utilization of services between tribal and non-tribal pregnant women. Settings and Design: This was a descriptive cum qualitative study conducted in Thariode Gramapanchayat in the Wayanad district of Kerala. Materials and Methods: Among all women who had registered their pregnancies in the 5 sub-centres under CHC Thariode and had delivered between September 2009 and October 2010, equal numbers of tribal and non-tribal ante-natal women, 35 each were interviewed in-depth using a semi-structured questionnaire. Statistical Analysis Used: Quantitative data was analysed using SPSS Version 16.0. Content analysis was done for qualitative data. Results: The determinants of utilization in tribal women were general awareness, affordability, accessibility and quality of services along with motivation by health workers. Among tribal antenatal women, 85% utilized maternal health care facilities fully compared to 100% among non-tribal women. Lower levels of education and lack of transport facilities were prime factors contributing to under utilization by tribal women. Conclusions: Affordable, accessible and good quality of services in the public health system in Kerala and motivation by health workers were important contributing factors for better utilization of maternal care services. PMID:24678214

Origin and spatial distribution of metals in moss samples in Albania: A hotspot of heavy metal contamination in Europe.

PubMed

Lazo, Pranvera; Steinnes, Eiliv; Qarri, Flora; Allajbeu, Shaniko; Kane, Sonila; Stafilov, Trajce; Frontasyeva, Marina V; Harmens, Harry

2018-01-01

This study presents the spatial distribution of 37 elements in 48 moss samples collected over the whole territory of Albania and provides information on sources and factors controlling the concentrations of elements in the moss. High variations of trace metals indicate that the concentrations of elements are affected by different factors. Relations between the elements in moss, geochemical interpretation of the data, and secondary effects such as redox conditions generated from local soil and/or long distance atmospheric transport of the pollutants are discussed. Zr normalized data, and the ratios of different elements are calculated to assess the origin of elements present in the current moss samples with respect to different geogenic and anthropogenic inputs. Factor analysis (FA) is used to identify the most probable sources of the elements. Four dominant factors are identified, i.e. natural contamination; dust emission from local mining operations; atmospheric transport of contaminants from local and long distance sources; and contributions from air borne marine salts. Mineral particle dust from local emission sources is classified as the most important factor affecting the atmospheric deposition of elements accumulated in the current moss samples. The open slag dumps of mining operation in Albania is probably the main factor contributing to high contents of Cr, Ni, Fe, Ti and Al in the moss. Enrichment factors (EF) were calculated to clarify whether the elements in the present moss samples mainly originate from atmospheric deposition and/or local substrate materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors Affecting Outcomes in Cochlear Implant Recipients Implanted With a Perimodiolar Electrode Array Located in Scala Tympani.

PubMed

Holden, Laura K; Firszt, Jill B; Reeder, Ruth M; Uchanski, Rosalie M; Dwyer, Noël Y; Holden, Timothy A

2016-12-01

To identify primary biographic and audiologic factors contributing to cochlear implant (CI) performance variability in quiet and noise by controlling electrode array type and electrode position within the cochlea. Although CI outcomes have improved over time, considerable outcome variability still exists. Biographic, audiologic, and device-related factors have been shown to influence performance. Examining CI recipients with consistent array type and electrode position may allow focused investigation into outcome variability resulting from biographic and audiologic factors. Thirty-nine adults (40 ears) implanted for at least 6 months with a perimodiolar electrode array known (via computed tomography [CT] imaging) to be in scala tympani participated. Test materials, administered CI only, included monosyllabic words, sentences in quiet and noise, and spectral ripple discrimination. In quiet, scores were high with mean word and sentence scores of 76 and 87%, respectively; however, sentence scores decreased by an average of 35 percentage points when noise was added. A principal components (PC) analysis of biographic and audiologic factors found three distinct factors, PC1 Age, PC2 Duration, and PC3 Pre-op Hearing. PC1 Age was the only factor that correlated, albeit modestly, with speech recognition in quiet and noise. Spectral ripple discrimination strongly correlated with speech measures. For these recipients with consistent electrode position, PC1 Age was related to speech recognition performance. Consistent electrode position may have contributed to high speech understanding in quiet. Inter-subject variability in noise may have been influenced by auditory/cognitive processing, known to decline with age, and mechanisms that underlie spectral resolution ability.

Molecular deformation mechanisms of the wood cell wall material.

PubMed

Jin, Kai; Qin, Zhao; Buehler, Markus J

2015-02-01

Wood is a biological material with outstanding mechanical properties resulting from its hierarchical structure across different scales. Although earlier work has shown that the cellular structure of wood is a key factor that renders it excellent mechanical properties at light weight, the mechanical properties of the wood cell wall material itself still needs to be understood comprehensively. The wood cell wall material features a fiber reinforced composite structure, where cellulose fibrils act as stiff fibers, and hemicellulose and lignin molecules act as soft matrix. The angle between the fiber direction and the loading direction has been found to be the key factor controlling the mechanical properties. However, how the interactions between theses constitutive molecules contribute to the overall properties is still unclear, although the shearing between fibers has been proposed as a primary deformation mechanism. Here we report a molecular model of the wood cell wall material with atomistic resolution, used to assess the mechanical behavior under shear loading in order to understand the deformation mechanisms at the molecular level. The model includes an explicit description of cellulose crystals, hemicellulose, as well as lignin molecules arranged in a layered nanocomposite. The results obtained using this model show that the wood cell wall material under shear loading deforms in an elastic and then plastic manner. The plastic regime can be divided into two parts according to the different deformation mechanisms: yielding of the matrix and sliding of matrix along the cellulose surface. Our molecular dynamics study provides insights of the mechanical behavior of wood cell wall material at the molecular level, and paves a way for the multi-scale understanding of the mechanical properties of wood. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

NASA Astrophysics Data System (ADS)

Smith, Hugh G.; Sheridan, Gary J.; Nyman, Petter; Child, David P.; Lane, Patrick N. J.; Hotchkis, Michael A. C.; Jacobsen, Geraldine E.

2012-02-01

Fine sediment supply has been identified as an important factor contributing to the initiation of runoff-generated debris flows after fire. However, despite the significance of fines for post-fire debris flow generation, no investigations have sought to quantify sources of this material in debris flow affected catchments. In this study, we employ fallout radionuclides ( 137Cs, 210Pb ex and 239,240Pu) as tracers to measure proportional contributions of fine sediment (< 10 μm) from hillslope surface and channel bank sources to levee and terminal fan deposits formed by post-fire debris flows in two forest catchments in southeastern Australia. While 137Cs and 210Pb ex have been widely used in sediment tracing studies, application of Pu as a tracer represents a recent development and was limited to only one catchment. The ranges in estimated proportional hillslope surface contributions of fine sediment to individual debris flow deposits in each catchment were 22-69% and 32-74%. The greater susceptibility of 210Pb ex to apparent reductions in the ash content of channel deposits relative to hillslope sources resulted in its exclusion from the final analysis. No systematic change in the proportional source contributions to debris flow deposits was observed with distance downstream from channel initiation points. Instead, spatial variability in source contributions was largely influenced by the pattern of debris flow surges forming the deposits. Linking the tracing analysis with interpretation of depositional evidence allowed reconstruction of temporal sequences in sediment source contributions to debris flow surges. Hillslope source inputs dominated most elevated channel deposits such as marginal levees that were formed under peak flow conditions. This indicated the importance of hillslope runoff and fine sediment supply for debris flow generation in both catchments. In contrast, material stored within channels that was deposited during subsequent surges was predominantly channel-derived. The results demonstrate that fallout radionuclide tracers may provide unique information on changing source contributions of fine sediment during debris flow events.

Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

NASA Astrophysics Data System (ADS)

Smith, Hugh; Sheridan, Gary; Nyman, Petter; Child, David; Lane, Patrick; Hotchkis, Michael

2013-04-01

The supply of fine sediment and ash has been identified as an important factor contributing to the initiation of runoff-generated debris flows after fire. However, despite the significance of fines for post-fire debris flow generation, no investigations have sought to quantify sources of this material in debris flow affected catchments. In this study, we employ fallout radionuclides (Cs-137, excess Pb-210 and Pu-239,240) as tracers to measure proportional contributions of fine sediment (<10 μm) from hillslope surface and channel bank sources to levee and terminal fan deposits formed by post-fire debris flows in two forest catchments in southeastern Australia. While Cs-137 and excess Pb-210 have been widely used in sediment tracing studies, application of Pu as a tracer represents a recent development and was limited to only one catchment. The estimated range in hillslope surface contributions of fine sediment to individual debris flow deposits in each catchment was 22-69% and 32-74%, respectively. No systematic change in the source contributions to debris flow deposits was observed with distance downstream from channel initiation points. Instead, spatial variability in source contributions was largely influenced by the pattern of debris flow surges forming the deposits. Linking the sediment tracing with interpretation of depositional evidence allowed reconstruction of temporal sequences in sediment source contributions to debris flow surges. Hillslope source inputs dominated most elevated channel deposits such as marginal levees that were formed under peak flow conditions. This indicated the importance of hillslope runoff and sediment supply for debris flow generation in both catchments. In contrast, material stored within channels that was deposited during subsequent surges was predominantly channel-derived. The results demonstrate that fallout radionuclide tracers may provide unique information on the changing source contributions of fine sediment during debris flow events.

User applications driven by the community contribution framework MPContribs in the Materials Project

DOE PAGES

Huck, P.; Gunter, D.; Cholia, S.; ...

2015-10-12

This paper discusses how the MPContribs framework in the Materials Project (MP) allows user-contributed data to be shown and analyzed alongside the core MP database. The MP is a searchable database of electronic structure properties of over 65,000 bulk solid materials, which is accessible through a web-based science-gateway. We describe the motivation for enabling user contributions to the materials data and present the framework's features and challenges in the context of two real applications. These use cases illustrate how scientific collaborations can build applications with their own 'user-contributed' data using MPContribs. The Nanoporous Materials Explorer application provides a unique searchmore » interface to a novel dataset of hundreds of thousands of materials, each with tables of user-contributed values related to material adsorption and density at varying temperature and pressure. The Unified Theoretical and Experimental X-ray Spectroscopy application discusses a full workflow for the association, dissemination, and combined analyses of experimental data from the Advanced Light Source with MP's theoretical core data, using MPContribs tools for data formatting, management, and exploration. The capabilities being developed for these collaborations are serving as the model for how new materials data can be incorporated into the MP website with minimal staff overhead while giving powerful tools for data search and display to the user community.« less

An inventory of factors that affect polysaccharide production by Phaeocystis globosa

NASA Astrophysics Data System (ADS)

van Rijssel, M.; Janse, I.; Noordkamp, D. J. B.; Gieskes, W. W. C.

2000-08-01

Phaeocystis material contains polysaccharides that are built from at least eight different monosaccharides. Differences have been reported between the carbohydrate composition of different Phaeocystis species, and also between samples taken from Phaeocystis globosa blooms in different areas. In order to elucidate factors that could play a role in determining variation in carbohydrate composition and production, a number of Phaeocystis globosa strains were studied under laboratory conditions. Although there was a clear distinction of a northern and a southern cluster in the Phaeocystis globosa strains based on RAPD analysis, the differences in the composition of the mucopolysaccharides were relatively small. The contribution of glucose, however, ranged from 7-85% of total sugars. A strain that was cultured in seawaters of diverse origin produced polysaccharides of a different composition, suggesting the effect of environmental factors. The presence of bacteria affected neither the amount, nor the composition of the carbohydrates that were produced by Phaeocystis globosa. Glucose is part of both the intracellular polysaccharide pool and of the mucopolysaccharides in the colony matrix. Using specific digestion of the intracellular chrysolaminaran by laminarinase, the distribution of polysaccharides over different pools could be assessed. During growth of an axenic, mucus-producing strain, the portion of glucose present as chrysolaminaran appeared to increase. The polyglucose that was not digested by laminarinase remains unidentified. This study shows that environmental factors rather than strain differences determine differences in the sugar composition of Phaeocystis globosa, especially with respect to the glucose content of the material. A difference in the contribution of glucose could be correlated to the portion of cells in the culture that are not in the colonies. Our study emphasises that for studying polysaccharide dynamics in Phaeocystis globosa it is important to be able to discriminate between the different polysaccharide pools. Preliminary results of an enzymatic approach were promising

The ultrasonic machining of silicon carbide / alumina composites

NASA Astrophysics Data System (ADS)

Nicholson, Garth Martyn John

Silicon carbide fibre reinforced alumina is a ceramic composite which was developed in conjunction with the Rolls-Royce Aerospace Group. The material is intended for use in the latest generation of jet engines, specifically for high temperature applications such as flame holders, combustor barrel segments and turbine blade tip seals. The material in question has properties which have been engineered by optimizing fibre volume fractions, weaves and fibre interface materials to meet the following main requirements : high thermal resistance, high thermal shock resistance and low density.Components intended for manufacture using this material will use the "direct metal oxidation" (DIMOX) method. This process involves manufacturing a near net shape component from the woven fibre matting, and infiltrating the matting with the alumina matrix material. Some of the components outlined require high tolerance features to be included in their design. The combustor barrel segments for example require slots to be formed within them for sealing purposes, the dimensions of these features preclude their formation using DIMOX, and therefore require a secondary process to be performed. Conventional machining techniques such as drilling, turning and milling cannot be used because of the brittle nature of the material. Electrodischarge machining (E.D.M.) cannot be used since the material is an insulator. Electrochemical machining (E.C.M.) cannot be used since the material is chemically inert. One machining method which could be used is ultrasonic machining (U.S.M.).The research programme investigated the feasibility of using ultrasonic machining as a manufacturing method for this new fibre reinforced composite. Two variations of ultrasonic machining were used : ultrasonic drilling and ultrasonic milling. Factors such as dimensional accuracy, surface roughness and delamination effects were examined. Previously performed ultrasonic machining experimental programmes were reviewed, as well as process models which have been developed. The process models were found to contain empirical constants which usually require specific material data for their calculation.Since a limited amount of the composite was available, and ultrasonic machining has many process variables, a Taguchi factorial experiment was conducted in order to ascertain the most relevant factors in machining. A full factorial experiment was then performed using the relevant factors. Techniques used in the research included both optical and scanning electron microscopy, surface roughness analysis, x-ray analysis and finite element stress analysis. A full set of machining data was obtained including relationships between the factors examined and both material removal rates, and surface roughness values. An attempt was made to explain these findings by examining established brittle fracture mechanisms. These established mechanisms did not seem to apply entirely to this material, an alternative method of material removal is therefore proposed. It is hoped that the data obtained from this research programme may contribute to the development of a more realistic mathematical model.

Tiny is mighty: seagrass beds have a large role in the export of organic material in the tropical coastal zone.

PubMed

Gillis, Lucy G; Ziegler, Alan D; van Oevelen, Dick; Cathalot, Cecile; Herman, Peter M J; Wolters, Jan W; Bouma, Tjeerd J

2014-01-01

Ecosystems in the tropical coastal zone exchange particulate organic matter (POM) with adjacent systems, but differences in this function among ecosystems remain poorly quantified. Seagrass beds are often a relatively small section of this coastal zone, but have a potentially much larger ecological influence than suggested by their surface area. Using stable isotopes as tracers of oceanic, terrestrial, mangrove and seagrass sources, we investigated the origin of particulate organic matter in nine mangrove bays around the island of Phuket (Thailand). We used a linear mixing model based on bulk organic carbon, total nitrogen and δ13C and δ15N and found that oceanic sources dominated suspended particulate organic matter samples along the mangrove-seagrass-ocean gradient. Sediment trap samples showed contributions from four sources oceanic, mangrove forest/terrestrial and seagrass beds where oceanic had the strongest contribution and seagrass beds the smallest. Based on ecosystem area, however, the contribution of suspended particulate organic matter derived from seagrass beds was disproportionally high, relative to the entire area occupied by mangrove forests, the catchment area (terrestrial) and seagrass beds. The contribution from mangrove forests was approximately equal to their surface area, whereas terrestrial contributions to suspended organic matter under contributed compared to their relative catchment area. Interestingly, mangrove forest contribution at 0 m on the transects showed a positive relationship with the exposed frontal width of the mangrove, indicating that mangrove forest exposure to hydrodynamic energy may be a controlling factor in mangrove outwelling. However we found no relationship between seagrass bed contribution and any physical factors, which we measured. Our results indicate that although seagrass beds occupy a relatively small area of the coastal zone, their role in the export of organic matter is disproportional and should be considered in coastal management especially with respect to their importance as a nutrient source for other ecosystems and organisms.

Combinatorial Enzyme Design Probes Allostery and Cooperativity in the Trypsin Fold

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

Page, Michael J.; Di Cera, Enrico; St. Louis-MED)

2010-06-14

Converting one enzyme into another is challenging due to the uneven distribution of important amino acids for function in both protein sequence and structure. We report a strategy for protein engineering allowing an organized mixing and matching of genetic material that leverages lower throughput with increased quality of screens. Our approach successfully tested the contribution of each surface-exposed loop in the trypsin fold alone and the cooperativity of their combinations towards building the substrate selectivity and Na{sup +}-dependent allosteric activation of the protease domain of human coagulation factor Xa into a bacterial trypsin. As the created proteases lack additional proteinmore » domains and protein co-factor activation mechanism requisite for the complexity of blood coagulation, they are stepping-stones towards further understanding and engineering of artificial clotting factors.« less

Materials for a new generation of vehicles

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

Grobstein, T.

1995-12-31

The Partnership for a New Generation of Vehicles (PNGV) is a national initiative with three goals: first, to significantly improve national competitiveness in manufacturing; second, to implement commercially viable innovations from ongoing research on conventional vehicles, and third, to develop a vehicle to achieve up to three times the fuel efficiency of today`s comparable vehicle (i.e., the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina). Note this vehicle will have the equivalent customer purchase price of today`s vehicles adjusted for economics, while meeting the customers` needs for quality, performance, and utility. Eight federal agencies are currently contributing to these goals,more » as well as the three principal US automobile manufacturers, numerous automotive component suppliers, research laboratories, and universities. Materials research and development is a significant effort within PNGV. The goals in this area include development of lightweight, recyclable materials for structural applications, high strength, long-life, high temperature materials for engine components, improved materials for alternative propulsion and energy storage systems, and cost-effective process technologies and component fabrication methods. Application of advanced materials to automobiles will involve consideration of diverse factors, including weight savings, affordability, recyclability, crashworthiness, repairability, and manufacturability.« less

Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS.

PubMed

Belsey, Natalie A; Cant, David J H; Minelli, Caterina; Araujo, Joyce R; Bock, Bernd; Brüner, Philipp; Castner, David G; Ceccone, Giacomo; Counsell, Jonathan D P; Dietrich, Paul M; Engelhard, Mark H; Fearn, Sarah; Galhardo, Carlos E; Kalbe, Henryk; Won Kim, Jeong; Lartundo-Rojas, Luis; Luftman, Henry S; Nunney, Tim S; Pseiner, Johannes; Smith, Emily F; Spampinato, Valentina; Sturm, Jacobus M; Thomas, Andrew G; Treacy, Jon P W; Veith, Lothar; Wagstaffe, Michael; Wang, Hai; Wang, Meiling; Wang, Yung-Chen; Werner, Wolfgang; Yang, Li; Shard, Alexander G

2016-10-27

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) inter-laboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and; particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage or sample preparation resulted in a variability in thickness of 53 %. The calculation method chosen by XPS participants contributed a variability of 67 %. However, variability of 12 % was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors, since this contributed a variability of 33 %. The results from the LEIS participants were more consistent, with variability of less than 10 % in thickness and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results.

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

USGS Publications Warehouse

Terziotti, Silvia; Hoos, Anne B.; Harned, Douglas; Garcia, Ana Maria

2010-01-01

As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

Suicidality among College and University Students: Contributing Factors and Preventive Response.

ERIC Educational Resources Information Center

Jones, Joan Wickham

This paper surveys and evaluates the research since 1975 on college and university student suicidality in the United States. It focuses on factors which contribute to suicidality, preventive responses to suicide and how well the preventive responses address the contributing factors. Contributing factors examined include various feeling states…

Biological responses to M13 bacteriophage modified titanium surfaces in vitro.

PubMed

Sun, Yuhua; Li, Yiting; Wu, Baohua; Wang, Jianxin; Lu, Xiong; Qu, Shuxin; Weng, Jie; Feng, Bo

2017-08-01

Phage-based materials have showed great potential in tissue engineering application. However, it is unknown what inflammation response will happen to this kind of materials. This work is to explore the biological responses to M13 bacteriophage (phage) modified titanium surfaces in vitro from the aspects of their interaction with macrophages, osteoblasts and mineralization behavior. Pretreated Ti surface, Ti surfaces with noncrosslinked phage film (APP) and crosslinked phage film (APPG) were compared. Phage films could limit the macrophage adhesion and activity due to inducing adherent-cell apoptosis. The initial inflammatory activity (24h) caused by phage films was relatively high with more production of TNF-α, but in the later stage (7-10days) inflammatory response was reduced with lower TNF-α, IL-6 and higher IL-10. In addition, phage films improved osteoblast adhesion, differentiation, and hydroapatite (HA)-forming via a combination of topographical and biochemcial cues. The noncrosslinked phage film displayed the best immunomodulatory property, osteogenic activity and HA mineralization ability. This work provides better understanding of inflammatory and osteogenetic activity of phage-based materials and contributes to their future application in tissue engineering. In vivo, the bone and immune cells share a common microenvironment, and are being affected by similar cytokines, signaling molecules, transcription factors and membrane receptors. Ideal implants should cause positive biological response, including adequate and appropriate inflammatory reaction, well-balanced bone formation and absorption. Phage-based materials have showed great potential in tissue engineering application. However, at present it is unknown what inflammation response will happen to this kind of materials. A good understanding of the immune response possibly induced by phage-based materials is needed. This work studied the osteoimmunomodulation property of phage films on titanium surface, involving inflammatory response, osteogenic activity and biomineralization ability. It provides more understanding of the phage-based materials and contributes to their future application in tissue engineering. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Boosting ORR Catalytic Activity by Integrating Pyridine-N Dopants, a High Degree of Graphitization, and Hierarchical Pores into a MOF-Derived N-Doped Carbon in a Tandem Synthesis.

PubMed

Liu, Dandan; Li, Liangjun; Xu, Huanfei; Dai, Pengcheng; Wang, Ying; Gu, Xin; Yan, Liting; Zhao, Guoming; Zhao, Xuebo

2018-05-18

N-doped carbon materials represent promising metal-free electrocatalysts for the oxygen reduction reaction (ORR), the cathode reaction in fuel cells, metal-air batteries, and so on. A challenge for optimizing the ORR catalytic activities of these electrocatalysts is to tune their local structures and chemical compositions in a rational and controlled way that can achieve the synergistic function of each factor. Herein, we report a tandem synthetic strategy that integrates multiple contributing factors into an N-doped carbon. With an N-containing MOF (ZIF-8) as the precursor, carbonization at higher temperatures leads to a higher degree of graphitization. Subsequent NH 3 etching of this highly graphitic carbon enabled the introduction of a higher content of pyridine-N sites and higher porosity. By optimizing these three factors, the resultant carbon materials displayed ORR activity that was far superior to that of carbon derived from a one-step pyrolysis. The onset potential of 0.955 V versus a reversible hydrogen electrode (RHE) and the half-wave potential of 0.835 V versus RHE are among the top ranks of metal-free ORR catalysts and are comparable to commercial Pt/C (20 wt %) catalysts. Kinetic studies revealed lower H 2 O 2 yields, higher electron-transfer numbers, and lower Tafel slopes for these carbon materials compared with that derived from a one-step carbonization. These findings verify the effectiveness of this tandem synthetic strategy to enhance the ORR activity of N-doped carbon materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prevalence and etiological profile of chronic obstructive pulmonary disease in nonsmokers

PubMed Central

Mahmood, Tariq; Singh, Ravindra Kumar; Kant, Surya; Shukla, Amitabh Das; Chandra, Alok; Srivastava, Rajneesh Kumar

2017-01-01

Background: Tobacco smoking has been recognized as the most important risk factor for chronic obstructive pulmonary disease (COPD) for a long time, but recent studies have shown that nonsmokers also contribute to a significant proportion of COPD. This study was performed to find out the proportion of nonsmoker individuals among COPD patients and to determine various etiologies in nonsmoker COPD patients. Materials and Methods: This study was an observational cross-sectional study conducted in Department of Pulmonary Medicine, MLN Medical College, Allahabad. A total of 200 COPD patients, aged >18 years of either gender with COPD, diagnosed by clinical and spirometric criteria (GOLD guideline) were included in the study. Results: Of the 200 COPD patients, the proportion of nonsmoker patients was 56.5%, and the smoker was 43.5%. Among 113 nonsmoker COPD patients, maximum number of patients (69.03%) belonged to low socioeconomic status but most important and statistically significant risk factor was exposure to biomass smoke (53.98%), other significant risk factors were treated pulmonary tuberculosis (32.74%), and long-standing asthma (14.16%). Risk factors that were not statistically significant were occupational exposure (9.73%), exposure to outdoor air pollution (3.54%), and lower respiratory tract infection during childhood (1.77%). The patients who were exposed to more than one risk factors, developed COPD at an earlier age. Conclusions: This study revealed that nonsmokers contribute a significant proportion of COPD patients. Multiple risk factors other than smoking also play a major role in the development of COPD, particularly exposure to biomass smoke, treated pulmonary tuberculosis, and long-standing asthma. PMID:28360458

Experimental and Computational Investigation of Structural Integrity of Dissimilar Metal Weld Between Ferritic and Austenitic Steel

NASA Astrophysics Data System (ADS)

Santosh, R.; Das, G.; Kumar, S.; Singh, P. K.; Ghosh, M.

2018-03-01

The structural integrity of dissimilar metal welded (DMW) joint consisting of low-alloy steel and 304LN austenitic stainless steel was examined by evaluating mechanical properties and metallurgical characteristics. INCONEL 82 and 182 were used as buttering and filler materials, respectively. Experimental findings were substantiated through thermomechanical simulation of the weld. During simulation, the effect of thermal state and stress distribution was pondered based on the real-time nuclear power plant environment. The simulation results were co-related with mechanical and microstructural characteristics. Material properties were varied significantly at different fusion boundaries across the weld line and associated with complex microstructure. During in-situ deformation testing in a scanning electron microscope, failure occurred through the buttering material. This indicated that microstructure and material properties synergistically contributed to altering the strength of DMW joints. Simulation results also depicted that the stress was maximum within the buttering material and made its weakest zone across the welded joint during service exposure. Various factors for the failure of dissimilar metal weld were analyzed. It was found that the use of IN 82 alloy as the buttering material provided a significant improvement in the joint strength and became a promising material for the fabrication of DMW joint.

Experimental and Computational Investigation of Structural Integrity of Dissimilar Metal Weld Between Ferritic and Austenitic Steel

NASA Astrophysics Data System (ADS)

Santosh, R.; Das, G.; Kumar, S.; Singh, P. K.; Ghosh, M.

2018-06-01

The structural integrity of dissimilar metal welded (DMW) joint consisting of low-alloy steel and 304LN austenitic stainless steel was examined by evaluating mechanical properties and metallurgical characteristics. INCONEL 82 and 182 were used as buttering and filler materials, respectively. Experimental findings were substantiated through thermomechanical simulation of the weld. During simulation, the effect of thermal state and stress distribution was pondered based on the real-time nuclear power plant environment. The simulation results were co-related with mechanical and microstructural characteristics. Material properties were varied significantly at different fusion boundaries across the weld line and associated with complex microstructure. During in-situ deformation testing in a scanning electron microscope, failure occurred through the buttering material. This indicated that microstructure and material properties synergistically contributed to altering the strength of DMW joints. Simulation results also depicted that the stress was maximum within the buttering material and made its weakest zone across the welded joint during service exposure. Various factors for the failure of dissimilar metal weld were analyzed. It was found that the use of IN 82 alloy as the buttering material provided a significant improvement in the joint strength and became a promising material for the fabrication of DMW joint.

Spacecraft Materials in the Space Flight Environment: International Space Station - May 2002 to May 2007

NASA Technical Reports Server (NTRS)

Golden, John; Lorenz, Mary J.; Alred, John; Koontz, Steven L.; Pedley, Michael

2008-01-01

The performance of ISS spacecraft materials and systems on prolonged exposure to the low-Earth orbit (LEO) space flight is reported in this paper. In-flight data, flight crew observations, and the results of ground-based test and analysis directly supporting programmatic and operational decision-making are presented. The space flight environments definitions (both natural and induced) used for ISS design, material selection, and verification testing are shown, in most cases, to be more severe than the actual flight environment accounting for the outstanding performance of ISS as a long mission duration spacecraft. No significant ISS material or system failures have been attributed to spacecraft-environments interactions. Nonetheless, ISS materials and systems performance data is contributing to our understanding of spacecraft material interactions in the spaceflight environment so as to reduce cost and risk for future spaceflight projects and programs. Orbital inclination (51.6o) and altitude (nominally near 360 km) determine the set of natural environment factors affecting the functional life of materials and systems on ISS. ISS operates in an electrically conducting environment (the F2 region of Earth s ionosphere) with well-defined fluxes of atomic oxygen, other charged and neutral ionospheric plasma species, solar UV, VUV, and x-ray radiation as well as galactic cosmic rays, trapped radiation, and solar cosmic rays (1-4). The LEO micrometeoroid and orbital debris environment is an especially important determinant of spacecraft design and operations (5, 6). The magnitude of several environmental factors varies dramatically with latitude and longitude as ISS orbits the Earth (1-4). The high latitude orbital environment also exposes ISS to higher fluences of trapped energetic electrons, auroral electrons, solar cosmic rays, and galactic cosmic rays (1-4) than would be the case in lower inclination orbits, largely as a result of the overall shape and magnitude of the geomagnetic field (1-4). As a result, ISS exposure to many environmental factors can vary dramatically along a particular orbital ground track, and from one ground track to the next, during any 24-hour period.

Observation of Solar Wind Charge Exchange Emission from Exospheric Material in and Outside Earth's Magnetosheath

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Collier, M. R.; Cravens, T.; Kuntz, K. D.; Lepri, S. T.; Robertson, I.; Tomas, L.

2008-01-01

A long XMM-Newton exposure is used to observe solar wind charge exchange (SWCX) emission from exospheric material in and outside Earth s magnetosheath. The light curve of the O VII (0.5-0.62 keV) band is compared with a model for the expected emission, and while the emission is faint and the light curve has considerable scatter, the correlation is significant to better than 99.9%. This result demonstrates the validity of the geocoronal SWCX emission model for predicting a contribution to astrophysical observations to a scale factor of order unity (1.36). The results also demonstrate the potential utility of using X-ray observations to study global phenomena of the magnetosheath which currently are only investigated using in situ measurements.

A review of the impact of the environment on aerogenerator materials

NASA Astrophysics Data System (ADS)

Mortimer, A. R.

Factors which contribute to the unreliability of windpowered generators are examined, with specific regard to the availability of materials, durability, cost, ease of production, and ease of repair. The effects of wind loading and methods for testing salt air contaminants are discussed, along with the effect of moisture, of salt air on lubricants, of microbiological attack, of UV radiation, rain erosion, and icing. The probability of bird strikes is statistically defined, and consideration is given to electrostatic charging, lightning strikes, temperature changes, the corrosion of rubber by ozone, the effects of guano, and wet dry pollution. The visual, EM, and acoustic effects of wind turbines are explored, and production processes which may affect the integrity of the structure are outlined. Finally, failure mechanisms due to salt-air environments are detailed.

Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study.

PubMed

Kohli, Shivani; Bhatia, Shekhar

2015-01-01

Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI) and Acrylux (Ruthinium). Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal) and another group of each material in cola (Pepsi) as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi). The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

Housing Conditions Contribute to Underweight in Children: An Example From Rural Villages in Southeast Sulawesi, Indonesia.

PubMed

Tasnim, Tasnim; Dasvarma, Gouranga; Mwanri, Lillian

2017-09-01

The prevalence of underweight in children under 5 years of age is anomalously high in Konawe District, Southeast Sulawesi Province, Indonesia. This state of affairs may be related to poor housing conditions, such as limited access to clean water, the absence of a sanitary latrine, and the use of poor housing materials. Therefore, this study aimed to examine the effect of housing conditions on underweight in under-5 children in Konawe District. This study was conducted in 2013 in 5 health centres in Konawe District, Southeast Sulawesi Province, and used a case-control study design. The study recruited 400 under-5 children, including 100 of whom were cases and 300 of whom were age-matched controls (1:3). Cases were underweight children, while the controls were children with a normal nutritional status. The independent variables were the availability and types of water and latrine facilities and housing materials (roof, wall, and floor). The statistical analysis used Cox regression. A lack of water availability (odds ratio [OR], 5.0; 95% confidence interval [CI], 2.7 to 9.5; p<0.001), a lack of latrine availability in the home (OR, 2.5; 95% CI, 1.5 to 4.0; p<0.001), and poor-quality roofing materials (OR, 1.7; 95% CI, 1.1 to 2.7; p<0.02) significantly contributed to underweight in children. In contrast, the walls and the floors did not contribute to under-5 year children being underweight (p=0.09 and p=0.71, respectively). Sanitation facilities and roofing were identified as important factors to address in order to improve children's nutritional status. Children's health status was directly impacted by food intake via their nutritional status.

Characterization of photochromic and photorefractive chromophores

NASA Astrophysics Data System (ADS)

Moylan, Christopher R.; McComb, I. H.; Twieg, Robert J.; Wortmann, Ruediger W.

1997-01-01

Although photorefractive materials are those that exhibit both appreciable electro-optic and photoconductive behavior, the chromophore parameters that lead to large electro-optic coefficients have not so far led to similar photorefractive performance. Recently, it has been shown that the electro- optic contribution is one of two principal contributions to the overall photorefractive behavior, and that it is usually the smaller of the two. The larger factor, first referred to in the literature as an 'orientational enhancement,' is due to the birefringence of the chromophore: the difference in polarizability parallel to the dipole moment and perpendicular to it. A figure of merit incorporating both effects has been derived, although its determination is more difficult than that for purely electro-optic materials. The polarizability anisotropy is a function of all three components of the diagonalized polarizability tensor. Two expressions for these three parameters can be obtained by index of refraction and light scattering measurements on chromophores in solution. The third must be estimated. Results from this new characterization protocol are presented and compared with the results of photorefractive experiments on materials containing the tested chromophores. Another class of compounds has also been found to be of potential use in holographic storage, in this case write- once applications. These chromophores undergo an irreversible photochromic reaction that is triplet sensitized. A mechanism is proposed for this reaction and supporting data provided.

Dependence of Microelastic-plastic Nonlinearity of Martensitic Stainless Steel on Fatigue Damage Accumulation

NASA Technical Reports Server (NTRS)

Cantrell, John H.

2006-01-01

Self-organized substructural arrangements of dislocations formed in wavy slip metals during cyclic stress-induced fatigue produce substantial changes in the material microelastic-plastic nonlinearity, a quantitative measure of which is the nonlinearity parameter Beta extracted from acoustic harmonic generation measurements. The contributions to Beta from the substructural evolution of dislocations and crack growth for fatigued martensitic 410Cb stainless steel are calculated from the Cantrell model as a function of percent full fatigue life to fracture. A wave interaction factor f(sub WI) is introduced into the model to account experimentally for the relative volume of material fatigue damage included in the volume of material swept out by an interrogating acoustic wave. For cyclic stress-controlled loading at 551 MPa and f(sub WI) = 0.013 the model predicts a monotonic increase in Beta from dislocation substructures of almost 100 percent from the virgin state to roughly 95 percent full life. Negligible contributions from cracks are predicted in this range of fatigue life. However, over the last five percent of fatigue life the model predicts a rapid monotonic increase of Beta by several thousand percent that is dominated by crack growth. The theoretical predictions are in good agreement with experimental measurements of 410Cb stainless steel samples fatigued in uniaxial, stress-controlled cyclic loading at 551 MPa from zero to full tensile load with a measured f(sub WI) of 0.013.

Connectivity of streams and wetlands to downstream waters: An integrated systems framework

USGS Publications Warehouse

Leibowitz, Scott G.; Wigington, Parker J.; Schoefield, Kate A.; Alexander, Laurie C.; Vanderhoof, Melanie; Golden, Heather E.

2018-01-01

Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.

Improving treatment in Hispanic/Latino patients.

PubMed

Cersosimo, Eugenio; Musi, Nicolas

2011-10-01

The prevalence of type 2 diabetes mellitus is higher in Hispanic/Latino individuals living in the United States compared with their non-Hispanic white counterparts. Many factors contribute to the increased prevalence of type 2 diabetes, including biological characteristics, socioeconomic conditions, and cultural aspects. The contribution of genetics to the risk of type 2 diabetes in Hispanic/Latino patients is becoming increasingly clear, but this inherent risk factor cannot be modified. However, certain socioeconomic and cultural factors, such as reduced access to healthcare, language barriers, cultural beliefs, and lack of cultural competence by the healthcare provider, are modifiable and should be overcome in order to improve the management of type 2 diabetes in Hispanic/Latino patients. At the healthcare system level, policies should be put into place to reduce disparities between Hispanics/Latinos and non-Hispanic whites regarding health insurance coverage and access to healthcare. At the healthcare provider and patient level, cultural beliefs should be taken into consideration when selecting adequate treatment. Overall, type 2 diabetes management should be individualized by identifying the preferred language and level of acculturation for each patient. These considerations are necessary to further improve communication through culturally appropriate educational materials and programs. These strategies may help to overcome the barriers in the treatment of type 2 diabetes in Hispanic/Latino patients. Copyright © 2011 Elsevier Inc. All rights reserved.

Numerical modeling of polymorphic transformation of oleic acid via near-infrared spectroscopy and factor analysis.

PubMed

Liu, Ling; Cheng, Yuliang; Sun, Xiulan; Pi, Fuwei

2018-05-15

Near-infrared (NIR) spectroscopy as a tool for direct and quantitatively screening the minute polymorphic transitions of bioactive fatty acids was assessed basing on a thermal heating process of oleic acid. Temperature-dependent NIR spectral profiles indicate that dynamical variances of COOH group dominate its γ → α phase transition, while the transition from active α to β phase mainly relates to the conformational transfer of acyl chain. Through operating multivariate curve resolution-alternating least squares with factor analysis, instantaneous contribution of each active polymorph during the transition process was illustrated for displaying the progressive evolutions of functional groups. Calculated contributions reveal that the α phase of oleic acid initially is present at around -18 °C, but sharply grows up around -2.2 °C from the transformation of γ phase and finally disappears at the melting point. On the other hand, the β phase of oleic acid is sole self-generation after melt even it embryonically appears at -2.2 °C. Such mathematical approach based on NIR spectroscopy and factor analysis calculation provides a volatile strategy in quantitatively exploring the transition processes of bioactive fatty acids; meanwhile, it maintains promising possibility for instantaneous quantifying each active polymorph of lipid materials. Copyright © 2018 Elsevier B.V. All rights reserved.

Motivation of university and non-university stakeholders to change medical education in Vietnam.

PubMed

Luu, Ngoc Hoat; Nguyen, Lan Viet; van der Wilt, G J; Broerse, J; Ruitenberg, E J; Wright, E P

2009-07-24

Both university and non-university stakeholders should be involved in the process of curriculum development in medical schools, because all are concerned with the competencies of the graduates. That may be difficult unless appropriate strategies are used to motivate each stakeholder. From 1999 to 2006, eight medical schools in Vietnam worked together to change the curriculum and teaching for general medical students to make it more community oriented. This paper describes the factors that motivated the different stakeholders to participate in curriculum change and teaching in Vietnamese medical schools and the activities to address those factors and have sustainable contributions from all relevant stakeholders. Case study analysis of contributions to the change process, using reports, interviews, focus group discussions and surveys and based on Herzberg's Motivation Theory to analyze involvement of different stakeholders. Different stakeholders were motivated by selected activities, such as providing opportunities for non-university stakeholders to share their opinions, organizing interactions among university stakeholders, stimulating both bottom-up and top-down inputs, focusing on learning from each other, and emphasizing self-motivation factors. The Herzberg Motivation theory helped to identify suitable approaches to ensure that teaching topics, materials and assessment methods more closely reflected the health care needs of the community. Other medical schools undertaking a reform process may learn from this experience.

Numerical modeling of polymorphic transformation of oleic acid via near-infrared spectroscopy and factor analysis

NASA Astrophysics Data System (ADS)

Liu, Ling; Cheng, Yuliang; Sun, Xiulan; Pi, Fuwei

2018-05-01

Near-infrared (NIR) spectroscopy as a tool for direct and quantitatively screening the minute polymorphic transitions of bioactive fatty acids was assessed basing on a thermal heating process of oleic acid. Temperature-dependent NIR spectral profiles indicate that dynamical variances of COOH group dominate its γ → α phase transition, while the transition from active α to β phase mainly relates to the conformational transfer of acyl chain. Through operating multivariate curve resolution-alternating least squares with factor analysis, instantaneous contribution of each active polymorph during the transition process was illustrated for displaying the progressive evolutions of functional groups. Calculated contributions reveal that the α phase of oleic acid initially is present at around -18 °C, but sharply grows up around -2.2 °C from the transformation of γ phase and finally disappears at the melting point. On the other hand, the β phase of oleic acid is sole self-generation after melt even it embryonically appears at -2.2 °C. Such mathematical approach based on NIR spectroscopy and factor analysis calculation provides a volatile strategy in quantitatively exploring the transition processes of bioactive fatty acids; meanwhile, it maintains promising possibility for instantaneous quantifying each active polymorph of lipid materials.

Species-specific challenges in dog cloning.

PubMed

Kim, G A; Oh, H J; Park, J E; Kim, M J; Park, E J; Jo, Y K; Jang, G; Kim, M K; Kim, H J; Lee, B C

2012-12-01

Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning. © 2012 Blackwell Verlag GmbH.

Aviation occupant survival factors: an empirical study of the SQ006 accident.

PubMed

Chang, Yu-Hern; Yang, Hui-Hua

2010-03-01

We present an empirical study of Singapore Airline (SIA) flight SQ006 to illustrate the critical factors that influence airplane occupant survivability. The Fuzzy Delphi Method was used to identify and rank the survival factors that may reduce injury and fatality in potentially survivable accidents. This is the first attempt by a group from both the public and private sectors in Taiwan to focus on cabin-safety issues related to survival factors. We designed a comprehensive survey based on our discussions with aviation safety experts. We next designed an array of important cabin-safety dimensions and then investigated and selected the critical survival factors for each dimension. Our findings reveal important cabin safety and survivability information that should provide a valuable reference for developing and evaluating aviation safety programs. We also believe that the results will be practical for designing cabin-safety education material for air travelers. Finally, the major contribution of this research is that it has identified 47 critical factors that influence accident survivability; therefore, it may encourage improvements that will promote more successful cabin-safety management. Copyright 2009 Elsevier Ltd. All rights reserved.

Wild plants as tools for the remediation of abandoned mining sites with a high arsenic content

NASA Astrophysics Data System (ADS)

Martínez-Lopez, Salvadora; Martínez-Sanchez, MJose; Perez-Sirvent, Carmen; Martínez, Lucia B.; Bech, Jaume

2014-05-01

The aim of this study was to assess the environmental risk posed by arsenic when new vegetation types are introduced, analyzing the transfer of arsenic in different plant species that grow spontaneously in mining areas of SE Spain (Sierra Minera of Cartagena), and the contribution of such plants to the environmental risk represented by their ingestion by animals living in the same ecosystems. When dealing with remediation projects in zones affected by mining activities, the risk posed by the ingestion of the plants by fauna is often forgotten. To study the transfer to the trophic chain, two mammals, sheep and vole, were selected. The risk analysis was centered in the contribution of these natural plants to the ingestion calculated. For this study, 21 vegetal species naturally growing in the soils were collected from the Sierra Minera. The vegetal material studied is clearly associated with the Mediterranean Region (S.E. of Spain) and the plant species collected are endemisms and plants characteristic of the zone. Physico-chemical properties were obtained by means of the usual procedures. To determine the arsenic content, the soil samples and plant materials were digested in a microwave system and the arsenic concentration was determined using atomic fluorescence spectrometry with an automated continuous flow hydride generation system. A semiquantitative estimation of the mineralogical composition of the samples was made by X Ray Diffraction analysis. The soils were classified into three groups: Low (group 1) (7-35 mg/kg) medium (group 2) (35-327 mg/kg) and high (group 3) (> 327 mg/kg), according to their As content. The mineralogy and As content of the soils studied depends on the materials related with mining activity. The descriptive statistical analysis of the population of plants studied showed the As range in roots to be 0.31-150 mg/kg while leaf concentrations were lower (0.21-83.4 mg/kg). The potential risk of As entering the food chain through of the plant species has been evaluated. The exposure pathway considered has been oral ingestion, calculating the contribution of the plant to the daily dose based on the arsenic concentration in the leaves of the plants analyzed. The Bioconcentration Factors are generally very low, the transfer Factors being somewhat higher although rarely exceed the unity. When dealing with phytoremediation of contaminated sites, the contribution of the As level in plants to the daily diet of animals should be used as an indicator for a suitable selection of the vegetal species to be used.

Vehicle Assembly Building Fire Mishap Investigation Report. Volume I of V

NASA Technical Reports Server (NTRS)

Kight, Ira; Luciano, Steven; Stevens, Michael B.; Farley, W. Max; Collins, Bryce D.; Potterger, William C.; Levesque, Jodi

2005-01-01

On January 13, 2005, at approximately 1355, smoke was noticed on the 4th floor of D Tower in the Vehicle Assembly Building (VAB). Subsequently, a 911 call was made, a fire alarm pull station was activated, and the VAB was evacuated. The source of the smoke was determined to be a fire on the Low Bay M/N section roof near the Launch Control Center (LCC) Crossover. Due to the high visibility of the mishap, the KSC Center Director appointed a Mishap Investigation Board. Damage to government property was limited to the roof and a small number of ceiling tiles that were damaged by the fire fighters during the response. At the time of the mishap, there were hazardous commodities in the VAB including Solid Rocket Motors (SRMs) with open grain due to Solid Rocket Booster (SRB) igniter inspections. The Board agrees with the SGS Fire Services' theory that large amounts of smoke concentrated in the VAB D Tower and moved downward into the cable tunnel. The Board determined the proximate cause of this incident to be torching. HRI was installing a torch applied roof membrane which resulted in the ignition of combustible materials under the membrane near a wooden roof expansion joint. The torch applied roofing method is a universally accepted safe industry practice when applied to non-combustible surfaces. The combination of an open flame torch and combustible materiaLs presents an increased level of risk even with skilled applicators. The addition of high winds to this combination results in a risk the Board thinks can not be adequately mitigated. An appropriate risk assessment and analysis must be performed on the proposed roofing method to be used on high visibility facilities which represent unique national assets even when using common industry practices for repair and modification. The Board identified three root causes which contributed to or created the proximate cause and, if eliminated or modified, would have prevented the mishap: 1. Combustible materials in existing roof system 2. Wind speed and direction 3. Inadequate fire watch technique. Two contributing factors were identified which may have contributed to the occurrence but, if eliminated or modified, would not have prevented the occurrence: 1. HRI rushed to dry in and seal the roof on January 13 because heavy rain was predicted for the next day 2. No guidance on torching in windy conditions A total of 17 significant observations were noted during this investigation, which could lead to another mishap, or increase the severity of a mishap, but were not contributing factors in this mishap.

A silicon metal-oxide-semiconductor electron spin-orbit qubit

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

Jock, Ryan Michael; Jacobson, Noah Tobias; Harvey-Collard, Patrick

Here, the silicon metal-oxide-semiconductor (MOS) material system is a technologically important implementation of spin-based quantum information processing. However, the MOS interface is imperfect leading to concerns about 1/f trap noise and variability in the electron g-factor due to spin–orbit (SO) effects. Here we advantageously use interface–SO coupling for a critical control axis in a double-quantum-dot singlet–triplet qubit. The magnetic field-orientation dependence of the g-factors is consistent with Rashba and Dresselhaus interface–SO contributions. The resulting all-electrical, two-axis control is also used to probe the MOS interface noise. The measured inhomogeneous dephasing time, T* 2m, of 1.6 μs is consistent with 99.95%more » 28Si enrichment. Furthermore, when tuned to be sensitive to exchange fluctuations, a quasi-static charge noise detuning variance of 2 μeV is observed, competitive with low-noise reports in other semiconductor qubits. This work, therefore, demonstrates that the MOS interface inherently provides properties for two-axis qubit control, while not increasing noise relative to other material choices.« less

A silicon metal-oxide-semiconductor electron spin-orbit qubit

DOE PAGES

Jock, Ryan Michael; Jacobson, Noah Tobias; Harvey-Collard, Patrick; ...

2018-05-02

Here, the silicon metal-oxide-semiconductor (MOS) material system is a technologically important implementation of spin-based quantum information processing. However, the MOS interface is imperfect leading to concerns about 1/f trap noise and variability in the electron g-factor due to spin–orbit (SO) effects. Here we advantageously use interface–SO coupling for a critical control axis in a double-quantum-dot singlet–triplet qubit. The magnetic field-orientation dependence of the g-factors is consistent with Rashba and Dresselhaus interface–SO contributions. The resulting all-electrical, two-axis control is also used to probe the MOS interface noise. The measured inhomogeneous dephasing time, T* 2m, of 1.6 μs is consistent with 99.95%more » 28Si enrichment. Furthermore, when tuned to be sensitive to exchange fluctuations, a quasi-static charge noise detuning variance of 2 μeV is observed, competitive with low-noise reports in other semiconductor qubits. This work, therefore, demonstrates that the MOS interface inherently provides properties for two-axis qubit control, while not increasing noise relative to other material choices.« less

Feasibility Studies of Palm Oil Mill Waste Aggregates for the Construction Industry.

PubMed

Kanadasan, Jegathish; Fauzi, Auni Filzah Ahmad; Razak, Hashim Abdul; Selliah, Paramananthan; Subramaniam, Vijaya; Yusoff, Sumiani

2015-09-22

The agricultural industry in Malaysia has grown rapidly over the years. Palm oil clinker (POC) is a byproduct obtained from the palm oil industry. Its lightweight properties allows for its utilization as an aggregate, while in powder form as a filler material in concrete. POC specimens obtained throughout each state in Malaysia were investigated to evaluate the physical, chemical, and microstructure characteristics. Variations between each state were determined and their possible contributory factors were assessed. POC were incorporated as a replacement material for aggregates and their engineering characteristics were ascertained. Almost 7% of density was reduced with the introduction of POC as aggregates. A sustainability assessment was made through greenhouse gas emission (GHG) and cost factor analyses to determine the contribution of the addition of POC to the construction industry. Addition of POC helps to lower the GHG emission by 9.6% compared to control specimens. By channeling this waste into the construction industry, an efficient waste-management system can be promoted; thus, creating a cleaner environment. This study is also expected to offer some guides and directions for upcoming research works on the incorporation of POC.

Scanning tunneling spectroscopy of the surface states of Dirac fermions in thermoelectrics based on bismuth telluride

NASA Astrophysics Data System (ADS)

Lukyanova, L. N.; Makarenko, I. V.; Usov, O. A.; Dementev, P. A.

2018-05-01

The morphology of the interlayer van der Waals surface and differential tunneling conductance in p-Bi2‑xSbxTe3‑ySey solid solutions were studied by scanning tunneling microscopy and spectroscopy in dependence on compositions. The topological characteristics of the Dirac fermion surface states were determined. It was shown that the thermoelectric power factor and the material parameter enhance with the shift of the Dirac point to the top of the valence band with the increasing of atomic substitution in these thermoelectrics. A correlation between topological characteristics, power factor and material parameters was found. A growth contribution of the surface states is determined by an increase of the Fermi velocity for large atomic substitutions of Bi at x > 1.5 and small substitutions in the Te sublattice (y = 0.06). In compositions with smaller substitutions at x = (1–1.3) and y = (0.06–0.09), similar effect of the surface states is determined by raising the surface concentration of charge carriers.

A silicon metal-oxide-semiconductor electron spin-orbit qubit.

PubMed

Jock, Ryan M; Jacobson, N Tobias; Harvey-Collard, Patrick; Mounce, Andrew M; Srinivasa, Vanita; Ward, Dan R; Anderson, John; Manginell, Ron; Wendt, Joel R; Rudolph, Martin; Pluym, Tammy; Gamble, John King; Baczewski, Andrew D; Witzel, Wayne M; Carroll, Malcolm S

2018-05-02

The silicon metal-oxide-semiconductor (MOS) material system is a technologically important implementation of spin-based quantum information processing. However, the MOS interface is imperfect leading to concerns about 1/f trap noise and variability in the electron g-factor due to spin-orbit (SO) effects. Here we advantageously use interface-SO coupling for a critical control axis in a double-quantum-dot singlet-triplet qubit. The magnetic field-orientation dependence of the g-factors is consistent with Rashba and Dresselhaus interface-SO contributions. The resulting all-electrical, two-axis control is also used to probe the MOS interface noise. The measured inhomogeneous dephasing time, [Formula: see text], of 1.6 μs is consistent with 99.95% 28 Si enrichment. Furthermore, when tuned to be sensitive to exchange fluctuations, a quasi-static charge noise detuning variance of 2 μeV is observed, competitive with low-noise reports in other semiconductor qubits. This work, therefore, demonstrates that the MOS interface inherently provides properties for two-axis qubit control, while not increasing noise relative to other material choices.

Thermal Analysis and Testing of Candidate Materials for PAIDAE Inflatable Aeroshell

NASA Technical Reports Server (NTRS)

DelCorso, Joseph A.; Bruce, Walter E., III; Liles, Kaitlin A.; Hughes, Stephen J.

2009-01-01

The Program to Advance Inflatable-Decelerators for Atmospheric Entry (PAIDAE) is a NASA project tasked with developing and evaluating viable inflatable-decelerator aeroshell geometries and materials. Thermal analysis of material layups supporting an inflatable aeroshell was completed in order to identify expected material response, failure times, and to establish an experimental test matrix to keep barrier layer materials from reaching critical temperature limits during thermal soak. Material layups were then tested in the 8- foot High Temperature Tunnel (8'HTT), where they were subjected to hypersonic aerothermal heating conditions, similar to those expected for a Mars entry. This paper presents a broad overview of the thermal analysis supporting multiple materials, and layup configurations tested in the 8'HTT at flight conditions similar to those that would be experienced during Mars entry trajectories. Direct comparison of TPS samples tested in the 8'HTT verify that the thermal model accurately predicted temperature profiles when there are up to four materials in the test layup. As the number of material layers in each test layup increase (greater than 4), the accuracy of the prediction decreases significantly. The inaccuracy of the model predictions for layups with more than four material layers is believed to be a result of the contact resistance values used throughout the model being inaccurate. In addition, the harsh environment of the 8'HTT, including hot gas penetrating through the material layers, could also be a contributing factor.

Factors Contributing to Urban Heat Island Development: A Global Perspective

NASA Astrophysics Data System (ADS)

Hertel, W.; Snyder, P. K.; Twine, T. E.

2012-12-01

Urban heat islands (UHIs) are the result of the urban core of a city encountering temperatures that are warmer than the surrounding rural areas. Temperature in the urban core can be 2-5°C warmer during the day and as much as 10°C warmer at night compared to outlying areas. This modification of the local climate can contribute to significant health-related impacts during heat waves, increased energy consumption, a decrease in air quality, deteriorating urban ecosystems, and enhancing the thermal pollution into urban water bodies. To understand the mechanisms contributing to the formation of UHIs and to identify sound mitigation strategies requires examining the UHIs of cities around the world to look for factors that enhance or minimize the heat island effect. Numerous factors influence the strength of the UHI, and vary from city to city. Population size and density influence the magnitude and spatial extent of the UHI. The ecosystem in which the city resides affects the rural climatology. Regional weather patterns can also influence the development of UHIs, with the frequency of certain types of weather conducive to the development of strong UHIs. Local geography such as proximity to water bodies and topography can influence UHI development. Cultural and regional influences such as the use of certain types of building materials, architecture, and the density of vegetation can all contribute towards the strength of a city's UHI. To better understand how UHIs develop and to understand the factors that influence them, we have undertaken the Islands in the Sun project, which includes an analysis of the UHIs of the largest cities in the world. In this study we examine how different factors have influenced the structure of the UHI and to identify factors that can mitigate and minimize their impact. Here we present a preliminary analysis of four metropolitan areas: Minneapolis-St. Paul, Buenos Aires, Riyadh, and Jakarta. In this study we investigate how various factors define a city's UHI. The cities presented here include some of the factors that can influence the UHI signal. The magnitude, diurnal and seasonal variability of the UHI is examined in each city through temperature records and satellite imagery. The UHIs are analyzed to assess the influences of the local geography and meteorology, the ecosystem in which the city resides, and the nature of the built environment. Because the Minneapolis-St. Paul region contains numerous water bodies, special emphasis is placed on the impact of its UHI on thermal pollution.

Atomic Oxygen Effects on Seal Leakage

NASA Technical Reports Server (NTRS)

Christensen, John R.; Underwood, Steve D.; Kamenetzky, Rachel R.; Vaughn, Jason A.

1999-01-01

Common Berthing Mechanism (CBM provides the structural interface between separate International Space Station (ISS) elements, such as the Laboratory and Node modules. The CBM consists of an active and a passive half that join together with structural bolts. The seal at this interface is the CBM-to-CBM molded seal. The CBM-to-CBM interface is assembled on orbit, thus the seals can be exposed to the space environment for up to 65 hours. Atomic Oxygen/Vacuum Ultraviolet radiation (AO/VUV) in space is a potential hazard to the seals. Testing was conducted to determine the effect on leakage of the CBM-to-CBM seal material exposed to AO/VUV. The sealing materials were S383 silicone and V835 fluorocarbon material. Control samples, which were not exposed to the AO/VUV environment, were used to ensure that ff any changes in leakage occurred, they could be attributed to the AO/VUV exposure. After exposure to the AO/VUV environment the leakage increase was dramatic for the fluorocarbon. This testing was a major contributing factor in selecting silicone as the CBM-to-CBM seal material.

Effect of transforming growth factor-beta and growth differentiation factor-5 on proliferation and matrix production by human bone marrow stromal cells cultured on braided poly lactic-co-glycolic acid scaffolds for ligament tissue engineering.

PubMed

Jenner, J M G Th; van Eijk, F; Saris, D B F; Willems, W J; Dhert, W J A; Creemers, Laura B

2007-07-01

Tissue engineering of ligaments based on biomechanically suitable biomaterials combined with autologous cells may provide a solution for the drawbacks associated with conventional graft material. The aim of the present study was to investigate the contribution of recombinant human transforming growth factor beta 1 (rhTGF-beta1) and growth differentiation factor (GDF)-5, known for their role in connective tissue regeneration, to proliferation and matrix production by human bone marrow stromal cells (BMSCs) cultured onto woven, bioabsorbable, 3-dimensional (3D) poly(lactic-co-glycolic acid) scaffolds. Cells were cultured for 12 days in the presence or absence of these growth factors at different concentrations. Human BMSCs attached to the suture material, proliferated, and synthesized extracellular matrix rich in collagen type I and collagen III. No differentiation was demonstrated toward cartilage or bone tissue. The addition of rhTGF-beta1 (1-10 ng/mL) and GDF-5 (10-100 ng/mL) increased cell content (p < 0.05), but only TGF-beta1 also increased total collagen production (p < 0.05) and collagen production per cell, which is a parameter indicating differentiation. In conclusion, stimulation with rhTGF-beta1, and to a lesser extent with GDF-5, can modulate human BMSCs toward collagenous soft tissue when applied to a 3D hybrid construct. The use of growth factors could play an important role in the improvement of ligament tissue engineering.

Contribution factor of wood properties of three poplar clones to strength of laminated veneer lumber

Treesearch

Fucheng Bao; Feng Fu; Elvin Choong; Chung-Yun Hse

2001-01-01

The term "Contribution Factor" (c.) was introduced in this paper to indicate the contribution ratio of solid wood properties to laminated veneer lumber (LVL) strength. Three poplar (Populus sp.) clones were studied, and the results showed that poplar with good solid wood properties has high Contribution Factor. The average Contribution...

Teacher Knowledge, Curriculum Materials, and Quality of Instruction: Lessons Learned and Open Issues

ERIC Educational Resources Information Center

Hill, Heather C.; Charalambous, Charalambos Y.

2012-01-01

This paper draws on four case studies to perform a cross-case analysis investigating the unique and joint contribution of mathematical knowledge for teaching (MKT) and curriculum materials to instructional quality. As expected, it was found that both MKT and curriculum materials matter for instruction. The contribution of MKT was more prevalent in…

From immunotoxicity to nanotherapy: the effects of nanomaterials on the immune system.

PubMed

Smith, Matthew J; Brown, Jared M; Zamboni, William C; Walker, Nigel J

2014-04-01

The potential for human exposure to the diverse and ever-changing world of nanoscale materials has raised concerns about their influence on health and disease. The novel physical and chemical properties of these materials, which are associated with their small size, complicate toxicological evaluations. Further, these properties may make engineered nanomaterials (ENMs) a prime target for interaction with the immune system following uptake by phagocytes. Undesired effects on antigen-presenting cells and other phagocytic cells are of concern due to the high likelihood of ENM uptake by these cells. In addition, ENM interactions with lymphocytes and other cell types can contribute to a varied spectrum of possible effects, including inflammation, hypersensitivity, and immunomodulation. Furthermore, the mast cell (a type of immune cell traditionally associated with allergy) appears to contribute to certain inflammatory and toxic effects associated with some ENMs. Although incidental exposure may be undesirable, nanomedicines engineered for various clinical applications provide opportunities to develop therapies that may or may not intentionally target the immune system. The interaction between ENMs and the immune system and the resulting pharmacokinetic and phenotypic responses are critical factors that dictate the balance between toxicity and clinical efficacy of nanotherapeutics.

Precise measurement of the performance of thermoelectric modules

NASA Astrophysics Data System (ADS)

Díaz-Chao, Pablo; Muñiz-Piniella, Andrés; Selezneva, Ekaterina; Cuenat, Alexandre

2016-08-01

The potential exploitation of thermoelectric modules into mass market applications such as exhaust gas heat recovery in combustion engines requires an accurate knowledge of their performance. Further expansion of the market will also require confidence on the results provided by suppliers to end-users. However, large variation in performance and maximum operating point is observed for identical modules when tested by different laboratories. Here, we present the first metrological study of the impact of mounting and testing procedures on the precision of thermoelectric modules measurement. Variability in the electrical output due to mechanical pressure or type of thermal interface materials is quantified for the first time. The respective contribution of the temperature difference and the mean temperature to the variation in the output performance is quantified. The contribution of these factors to the total uncertainties in module characterisation is detailed.

What can we learn from psychoanalysis and prospective studies about chemically dependent patients?

PubMed

Ramos, Sérgio de Paula

2004-04-01

Despite the common occurrence of drug abusers in the psychoanalytic clinic, contemporary literature on the subject, particularly among publications in the IJP, is sparse. This paper aims to review the most important psychoanalytic contributions on drug dependency in the past 100 years, then attempts to compare their postulations to the findings of pertinent prospective studies. In these patients, a persistent symbiotic object relationship is found, which ties them to narcissistic functioning, where drug use is viewed in the light of both pleasure without object and omnipotently controlled need. The author also discusses the possible contribution of the mother and father in the genesis of this condition, focusing on the compromise of the paternal function as the deciding factor. The theoretical and technical implications of this approach are illustrated by clinical material.

Determination of high-strength materials diamond grinding rational modes

NASA Astrophysics Data System (ADS)

Arkhipov, P. V.; Lobanov, D. V.; Rychkov, D. A.; Yanyushkin, A. S.

2018-03-01

The analysis of methods of high-strength materials abrasive processing is carried out. This method made it possible to determine the necessary directions and prospects for the development of shaping combined methods. The need to use metal bonded diamond abrasive tools in combination with a different kind of energy is noted to improve the processing efficiency and reduce the complexity of operations. The complex of experimental research on revealing the importance of mechanical and electrical components of cutting regimes, on the cutting ability of diamond tools, as well as the need to reduce the specific consumption of an abrasive wheel as one of the important economic indicators of the processing process is performed. It is established that combined diamond grinding with simultaneous continuous correction of the abrasive wheel contributes to an increase in the cutting ability of metal bonded diamond abrasive tools when processing high-strength materials by an average of 30% compared to diamond grinding. Particular recommendations on the designation of technological factors are developed depending on specific production problems.

Pneumatic jigging: Influence of operating parameters on separation efficiency of solid waste materials.

PubMed

Abd Aziz, Mohd Aizudin; Md Isa, Khairuddin; Ab Rashid, Radzuwan

2017-06-01

This article aims to provide insights into the factors that contribute to the separation efficiency of solid particles. In this study, a pneumatic jigging technique was used to assess the separation of solid waste materials that consisted of copper, glass and rubber insulator. Several initial experiments were carried out to evaluate the strengths and limitations of the technique. It is found that despite some limitations of the technique, all the samples prepared for the experiments were successfully separated. The follow-up experiments were then carried out to further assess the separation of copper wire and rubber insulator. The effects of air flow and pulse rates on the separation process were examined. The data for these follow-up experiments were analysed using a sink float analysis technique. The analysis shows that the air flow rate was very important in determining the separation efficiency. However, the separation efficiency may be influenced by the type of materials used.

Boomerang Satellites

NASA Astrophysics Data System (ADS)

Hesselbrock, Andrew; Minton, David A.

2017-10-01

We recently reported that the orbital architecture of the Martian environment allows for material in orbit around the planet to ``cycle'' between orbiting the planet as a ring, or as coherent satellites. Here we generalize our previous analysis to examine several factors that determine whether satellites accreting at the edge of planetary rings will cycle. In order for the orbiting material to cycle, tidal evolution must decrease the semi-major axis of any accreting satellites. In some systems, the density of the ring/satellite material, the surface mass density of the ring, the tidal parameters of the system, and the rotation rate of the primary body contribute to a competition between resonant ring torques and tidal dissipation that prevent this from occurring, either permanently or temporarily. Analyzing these criteria, we examine various bodies in our solar system (such as Saturn, Uranus, and Eris) to identify systems where cycling may occur. We find that a ring-satellite cycle may give rise to the current Uranian ring-satellite system, and suggest that Miranda may have formed from an early, more massive Uranian ring.

Optimum Installation of Sorptive Building Materials Using Contribution Ratio of Pollution Source for Improvement of Indoor Air Quality.

PubMed

Park, Seonghyun; Seo, Janghoo

2016-04-01

Reinforcing the insulation and airtightness of buildings and the use of building materials containing new chemical substances have caused indoor air quality problems. Use of sorptive building materials along with removal of pollutants, constant ventilation, bake-out, etc. are gaining attention in Korea and Japan as methods for improving such indoor air quality problems. On the other hand, sorptive building materials are considered a passive method of reducing the concentration of pollutants, and their application should be reviewed in the early stages. Thus, in this research, activated carbon was prepared as a sorptive building material. Then, computational fluid dynamics (CFD) was conducted, and a method for optimal installation of sorptive building materials was derived according to the indoor environment using the contribution ratio of pollution source (CRP) index. The results show that a method for optimal installation of sorptive building materials can be derived by predicting the contribution ratio of pollutant sources according to the CRP index.

Climate and soil factors influencing seedling recruitment of plant species used for dryland restoration

NASA Astrophysics Data System (ADS)

Muñoz-Rojas, Miriam; Erickson, Todd E.; Martini, Dylan C.; Dixon, Kingsley W.; Merritt, David J.

2016-06-01

Land degradation affects 10-20 % of drylands globally. Intensive land use and management, large-scale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales needs to be assessed and proven to be economically feasible.

Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS

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

Belsey, Natalie A.; Cant, David J. H.; Minelli, Caterina

We report the results of a VAMAS (Versailles Project on Advanced Materials and Standards) inter-laboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and; particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage or sample preparation resulted in a variability in thickness of 53 %. The calculation methodmore » chosen by XPS participants contributed a variability of 67 %. However, variability of 12 % was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors, since this contributed a variability of 33 %. The results from the LEIS participants were more consistent, with variability of less than 10 % in thickness and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results.« less

People use the memory for past-test heuristic as an explicit cue for judgments of learning.

PubMed

Serra, Michael J; Ariel, Robert

2014-11-01

When people estimate their memory for to-be-learned material over multiple study-test trials, they tend to base their judgments of learning (JOLs) on their test performance for those materials on the previous trial. Their use of this information-known as the memory for past-test (MPT) heuristic-is believed to be responsible for improvements in the relative accuracy (resolution) of people's JOLs across learning trials. Although participants seem to use past-test information as a major basis for their JOLs, little is known about how learners translate this information into a judgment of learning. Toward this end, in two experiments, we examined whether participants factored past-test performance into their JOLs in either an explicit, theory-based way or an implicit way. To do so, we had one group of participants (learners) study paired associates, make JOLs, and take a test on two study-test trials. Other participants (observers) viewed learners' protocols and made JOLs for the learners. Presumably, observers could only use theory-based information to make JOLs for the learners, which allowed us to estimate the contribution of explicit and implicit information to learners' JOLs. Our analyses suggest that all participants factored simple past-test performance into their JOLs in an explicit, theory-based way but that this information made limited contributions to improvements in relative accuracy across trials. In contrast, learners also used other privileged, implicit information about their learning to inform their judgments (that observers had no access to) that allowed them to achieve further improvements in relative accuracy across trials.

Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

NASA Astrophysics Data System (ADS)

Salonen, Heidi; Duchaine, Caroline; Létourneau, Valérie; Mazaheri, Mandana; Laitinen, Sirpa; Clifford, Sam; Mikkola, Raimo; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

2016-10-01

As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual words and combinations. References from relevant articles have also been searched. Analysis of the data showed that in residential, school, and office environments, the mean endotoxin loads in settled floor dust varied between 660 and 107,000 EU/m2, 2180 and 48,000 EU/m2, and 2700 and 12,890 EU/m2, respectively. Correspondingly, the mean endotoxin concentrations in indoor air varied between 0.04 and 1610 EU/m3 in residences, and 0.07 and 9.30 EU/m3 in schools and offices. There is strong scientific evidence indicating that age of houses (or housing unit year category), cleaning, farm or rural living, flooring materials (the presence of carpets), number of occupants, the presence of dogs or cats indoors, and relative humidity affect endotoxin loads in settled floor dust. The presence of pets (especially dogs) was extremely strongly associated with endotoxin concentrations in indoor air. However, as reviewed articles show inconsistency, additional studies on these and other possible predicting factors are needed.

When beauty is only skin deep; optimizing the sensitivity of specular neutron reflectivity for probing structure beneath the surface of thin filmsa)

NASA Astrophysics Data System (ADS)

Majkrzak, Charles F.; Carpenter, Elisabeth; Heinrich, Frank; Berk, Norman F.

2011-11-01

Specular neutron reflectometry has become an established probe of the nanometer scale structure of materials in thin film and multilayered form. It has contributed especially to our understanding of soft condensed matter of interest in polymer science, organic chemistry, and biology and of magnetic hard condensed matter systems. In this paper we examine a number of key factors which have emerged that can limit the sensitivity of neutron reflection as such a probe. Among these is loss of phase information, and we discuss how knowledge about material surrounding a film of interest can be applied to help resolve the problem. In this context we also consider what role the quantum phenomenon of interaction-free measurement might play in enhancing the statistical efficiency for obtaining reflectivity or transmission data.

OSTEOLYSIS AROUND TOTAL KNEE ARTHOPLASTY: A REVIEW OF PATHOGENETIC MECHANISMS

PubMed Central

Gallo, Jiri; Goodman, Stuart B.; Konttinen, Yrjö T.; Wimmer, Markus A.; Holinka, Martin

2014-01-01

Aseptic loosening and other wear-related complications are one of the most frequent late reasons for revision of total knee arthroplasty (TKA). Periprosthetic osteolysis (PPOL) predates aseptic loosening in many cases indicating the clinical significance of this pathogenic mechanism. A variety of implant-, surgery-, and host-related factors have been delineated to explain the development of PPOL. These factors influence the development of PPOL due to changes in mechanical stresses within the vicinity of the prosthetic device, excessive wear of the polyethylene liner, and joint fluid pressure and flow acting on the peri-implant bone. The process of aseptic loosening is initially governed by factors such as implant/limb alignment, device fixation quality, and muscle coordination/strength. Later large numbers of wear particles detached from TKAs trigger and perpetuate particle disease, as highlighted by progressive growth of inflammatory/granulomatous tissue around the joint cavity. An increased accumulation of osteoclasts at the bone-implant interface, an impairment of osteoblast function, mechanical stresses, and an increased production of joint fluid contribute to bone resorption and subsequent loosening of the implant. In addition, hypersensitivity and adverse reactions to metal debris may contribute to aseptic TKA failure but should be determined more precisely. Patient activity level appears to be the most important factor when the long-term development of PPOL is considered. Surgical technique, implant design, and material factors are the most important preventative factors because they influence both the generation of wear debris and excessive mechanical stresses. New generations of bearing surfaces and designs for TKA should carefully address these important issues in extensive preclinical studies. Currently, there is little evidence that PPOL can be prevented with pharmacological interventions. PMID:23669623

Some NASA contributions to human factors engineering: A survey

NASA Technical Reports Server (NTRS)

Behan, R. A.; Wendhausen, H. W.

1973-01-01

This survey presents the NASA contributions to the state of the art of human factors engineering, and indicates that these contributions have a variety of applications to nonaerospace activities. Emphasis is placed on contributions relative to man's sensory, motor, decisionmaking, and cognitive behavior and on applications that advance human factors technology.

Material system for tailorable white light emission and method for making thereof

DOEpatents

Smith, Christine A.; Lee, Howard W.

2004-08-10

A method of processing a composite material to tailor white light emission of the resulting composite during excitation. The composite material is irradiated with a predetermined power and for a predetermined time period to reduce the size of a plurality of nanocrystals and the number of a plurality of traps in the composite material. By this irradiation process, blue light contribution from the nanocrystals to the white light emission is intensified and red and green light contributions from the traps are decreased.

Material system for tailorable white light emission and method for making thereof

DOEpatents

Smith, Christine A [Livermore, CA; Lee, Howard W. H. [Fremont, CA

2009-05-19

A method of processing a composite material to tailor white light emission of the resulting composite during excitation. The composite material is irradiated with a predetermined power and for a predetermined time period to reduce the size of a plurality of nanocrystals and the number of a plurality of traps in the composite material. By this irradiation process, blue light contribution from the nanocrystals to the white light emission is intensified and red and green light contributions from the traps are decreased.

Composite Silica Aerogels Opacified with Titania

NASA Technical Reports Server (NTRS)

Paik, Jon-Ah; Sakamoto, Jeffrey; Jones, Steven; Fleurial, Jean-Pierre; DiStefano, Salvador; Nesmith, Bill

2009-01-01

A further improvement has been made to reduce the high-temperature thermal conductivities of the aerogel-matrix composite materials described in Improved Silica Aerogel Composite Materials (NPO-44287), NASA Tech Briefs, Vol. 32, No. 9 (September 2008), page 50. Because the contribution of infrared radiation to heat transfer increases sharply with temperature, the effective high-temperature thermal conductivity of a thermal-insulation material can be reduced by opacifying the material to reduce the radiative contribution. Therefore, the essence of the present improvement is to add an opacifying constituent material (specifically, TiO2 powder) to the aerogel-matrix composites.

Acoustic Quality Levels of Mosques in Batu Pahat

NASA Astrophysics Data System (ADS)

Azizah Adnan, Nor; Nafida Raja Shahminan, Raja; Khair Ibrahim, Fawazul; Tami, Hannifah; Yusuff, M. Rizal M.; Murniwaty Samsudin, Emedya; Ismail, Isham

2018-04-01

Every Friday, Muslims has been required to perform a special prayer known as the Friday prayers which involve the delivery of a brief lecture (Khutbah). Speech intelligibility in oral communications presented by the preacher affected all the congregation and determined the level of acoustic quality in the interior of the mosque. Therefore, this study intended to assess the level of acoustic quality of three public mosques in Batu Pahat. Good acoustic quality is essential in contributing towards appreciation in prayers and increasing khusyu’ during the worship, which is closely related to the speech intelligibility corresponding to the actual function of the mosque according to Islam. Acoustic parameters measured includes noise criteria (NC), reverberation time (RT) and speech transmission index (STI), and was performed using the sound level meter and sound measurement instruments. This test is carried out through the physical observation with the consideration of space and volume design as a factor affecting acoustic parameters. Results from all 3 mosques as the showed that the acoustic quality level inside these buildings are slightly poor which is at below 0.45 coefficients based on the standard. Among the factors that influencing the low acoustical quality are location, building materials, installation of sound absorption material and the number of occupants inside the mosque. As conclusion, the acoustic quality level of a mosque is highly depends on physical factors of the mosque such as the architectural design and space volume besides other factors as been identified by this study.

Dual fluorescence of excited state intra-molecular proton transfer of HBFO: mechanistic understanding, substituent and solvent effects.

PubMed

Yang, Wenjing; Chen, Xuebo

2014-03-07

A combined approach of the multiconfigurational perturbation theory with the Rice-Ramsperger-Kassel-Marcus methodology has been employed to calculate the minimum potential energy profiles and the rates of excited state intra-molecular proton transfer (ESIPT) for the WOLED material molecule of HBFO and its four meta- or para-substituted compounds in gas phase, acetonitrile and cyclohexane solvents. The kinetic control for these reactions is quantitatively determined and extensively studied on the basis of the accurate potential energy surfaces when the thermodynamic factor associated with the free energy change becomes negligible in the case of the existence of a significant barrier in the ESIPT process. These computational efforts contribute to a deep understanding of the ESIPT mechanism, dual emission characteristics, kinetic controlling factor, substituent and solvent effects for these material molecules. The white light emission is generated by the establishment of dynamic equilibrium between enol and keto forms in the charge transfer excited SCT((1)ππ*) state. The performance of white light emission is quantitatively demonstrated to be mainly sensitive to the molecular tailoring approach of the electronic properties of meta- or para- substituents by the modulation of the forward/backward ESIPT rate ratio. The quality of white light emission is slightly tunable through its surrounding solvent environment. These computational results will provide a useful strategy for the molecular design of OLED and WOLED materials.

Factors affecting the mechanical behavior of collagen hydrogels for skin tissue engineering.

PubMed

Pensalfini, Marco; Ehret, Alexander E; Stüdeli, Silvia; Marino, Daniela; Kaech, Andres; Reichmann, Ernst; Mazza, Edoardo

2017-05-01

The effect of the production factors yielding a functional dermal substitute was investigated by means of monotonic and cyclic uniaxial tensile tests, as well as electron microscopy visualizations. The role of (i) plastic compression, (ii) product incubation, and (iii) cell permanence in the collagenous matrix in order to achieve a skin-like behavior were characterized in terms of material and structural stiffness, in-plane kinematics, and cyclic response, as well as pore size and network density. The plastic compression resulted in a denser and stiffer material, while no corresponding change was observed in the behavior of the entire structure. This was related to the progressive reduction in product thickness and amount of excess water, rather than to formation of new crosslinks between fibers. Contrary, irrespective of the presence of human fibroblasts, the product incubation induced both material and structural stiffening, indicating the formation of a denser network. These results were confirmed by similar evolutions in the construct in-plane kinematics and cyclic stress reduction. Finally, comparison of constructs incubated in different culture media indicated a determinant contribution of the biochemical environment, rather than of the seeded cells, to the achieved mechanical properties. The observed features are relevant in terms of mechanical biocompatibility of the implant and might direct future optimizations of the production process in order to rapidly attain the desired mechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Extrinsic Contribution and Instability Properties in Lead-Based and Lead-Free Piezoceramics

PubMed Central

García, José Eduardo

2015-01-01

Piezoceramic materials generally exhibit a notable instability of their functional properties when they work under real external conditions. This undesirable effect, known as nonlinear behavior, is mostly associated with the extrinsic contribution to material response. In this article, the role of the ferroelectric domain walls’ motion in the nonlinear response in the most workable lead-based and lead-free piezoceramics is reviewed. Initially, the extrinsic origin of the nonlinear response is discussed in terms of the temperature dependence of material response. The influence of the crystallographic phase and of the phase boundaries on the material response are then reviewed. Subsequently, the impact of the defects created by doping in order to control the extrinsic contribution is discussed as a way of tuning material properties. Finally, some aspects related to the grain-size effect on the nonlinear response of piezoceramics are surveyed. PMID:28793681

Surface oxygen micropatterns on glow discharge polymer targets by photo irradiation

DOE PAGES

Reynolds, Hannah; Baxamusa, Salmaan; Haan, Steven W.; ...

2016-02-24

Recent simulations predict surface oxygen may be a significant source of disruptive perturbations in the implosion process of glow-discharge polymers (GDP) ablators at the National Ignition Facility. GDP material held in ambient atmospheric conditions showed an increase in mass when stored in light transparent containers, which suggests that photo exposure is a driving force for oxygen absorption. To investigate if surface oxygen is a contributing factor of disruptive perturbations during implosion, we developed a method to imprint a periodic micropattern of oxygen on the surface of GDP and used it to fabricate a flat sample for empirical testing.

Key issues in application of composites to transport aircraft

NASA Technical Reports Server (NTRS)

Stone, M.

1978-01-01

The application of composite materials to transport aircraft was identified and reviewed including the major contributing disciplines of design, manufacturing, and processing. Factors considered include: crashworthiness considerations (structural integrity, postcrash fires, and structural fusing), electrical/avionics subsystems integration, lightning, and P-static protection design; manufacturing development, evaluation, selection, and refining of tooling and curing procedures; and major joint design considerations. Development of the DC-10 rudder, DC-10 vertical stabilizer, and the DC-9 wing study project was reviewed. The Federal Aviation Administration interface and the effect on component design of compliance with Federal Aviation Regulation 25 Composite Guidelines are discussed.

Dynamic safety assessment of natural gas stations using Bayesian network.

PubMed

Zarei, Esmaeil; Azadeh, Ali; Khakzad, Nima; Aliabadi, Mostafa Mirzaei; Mohammadfam, Iraj

2017-01-05

Pipelines are one of the most popular and effective ways of transporting hazardous materials, especially natural gas. However, the rapid development of gas pipelines and stations in urban areas has introduced a serious threat to public safety and assets. Although different methods have been developed for risk analysis of gas transportation systems, a comprehensive methodology for risk analysis is still lacking, especially in natural gas stations. The present work is aimed at developing a dynamic and comprehensive quantitative risk analysis (DCQRA) approach for accident scenario and risk modeling of natural gas stations. In this approach, a FMEA is used for hazard analysis while a Bow-tie diagram and Bayesian network are employed to model the worst-case accident scenario and to assess the risks. The results have indicated that the failure of the regulator system was the worst-case accident scenario with the human error as the most contributing factor. Thus, in risk management plan of natural gas stations, priority should be given to the most probable root events and main contribution factors, which have identified in the present study, in order to reduce the occurrence probability of the accident scenarios and thus alleviate the risks. Copyright © 2016 Elsevier B.V. All rights reserved.

Abstract ID: 176 Geant4 implementation of inter-atomic interference effect in small-angle coherent X-ray scattering for materials of medical interest.

PubMed

Paternò, Gianfranco; Cardarelli, Paolo; Contillo, Adriano; Gambaccini, Mauro; Taibi, Angelo

2018-01-01

Advanced applications of digital mammography such as dual-energy and tomosynthesis require multiple exposures and thus deliver higher dose compared to standard mammograms. A straightforward manner to reduce patient dose without affecting image quality would be removal of the anti-scatter grid, provided that the involved reconstruction algorithms are able to take the scatter figure into account [1]. Monte Carlo simulations are very well suited for the calculation of X-ray scatter distribution and can be used to integrate such information within the reconstruction software. Geant4 is an open source C++ particle tracking code widely used in several physical fields, including medical physics [2,3]. However, the coherent scattering cross section used by the standard Geant4 code does not take into account the influence of molecular interference. According to the independent atomic scattering approximation (the so-called free-atom model), coherent radiation is indistinguishable from primary radiation because its angular distribution is peaked in the forward direction. Since interference effects occur between x-rays scattered by neighbouring atoms in matter, it was shown experimentally that the scatter distribution is affected by the molecular structure of the target, even in amorphous materials. The most important consequence is that the coherent scatter distribution is not peaked in the forward direction, and the position of the maximum is strongly material-dependent [4]. In this contribution, we present the implementation of a method to take into account inter-atomic interference in small-angle coherent scattering in Geant4, including a dedicated data set of suitable molecular form factor values for several materials of clinical interest. Furthermore, we present scatter images of simple geometric phantoms in which the Rayleigh contribution is rigorously evaluated. Copyright © 2017.

Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) explored as a potential electrochemical sensor for dopamine: surfactants significantly influence sensor capabilities.

PubMed

Khan, Aamar F; Brownson, Dale A C; Foster, Christopher W; Smith, Graham C; Banks, Craig E

2017-05-21

Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA. Previous studies utilising surfactant-free (pristine) 2D-hBN modified SPEs have shown a beneficial effect towards the detection of DA, AA and UA when compared to the underlying/unmodified graphite-based electrode. We show that the fabrication route utilised to prepare 2D-hBN is a vital experimental consideration, such that the beneficial effect previously reported is considerably reduced when surfactant exfoliated 2D-hBN is utilised. We demonstrate for the first time, through implementation of control experiments in the form of surfactant modified graphite electrodes, that sodium cholate is a major contributing factor to the aforementioned detrimental behaviour. The significance here is not in the material per se, but the fundamental knowledge of the surfactant and surface coverage changing the electrochemical properties of the material under investigation. Given the wide variety of ionic and non-ionic surfactants that are utilised in the manufacture of novel 2D materials, the control experiments reported herein need to be performed in order to de-convolute the electrochemical response and effectively evaluate the 'underlying surface/surfactant/2D materials' electrocatalytic contribution.

Adherence of Candida sp. to host tissues and cells as one of its pathogenicity features.

PubMed

Modrzewska, Barbara; Kurnatowski, Piotr

2015-01-01

The ability of Candida sp. cells to adhere to the mucosal surfaces of various host organs as well as synthetic materials is an important pathogenicity feature of those fungi which contributes to the development of infection. This property varies depending on the species of the fungus and is the greatest for C. albicans. The process of adhesion depends on plenty of factors related to the fungal and host cells as well as environmental conditions. The main adhesins present on the fungal cell wall are: Als, Epa, Hwp1, but also Eap1, Sun41, Csh1 and probably Hyr1; for adhesion significant are also secreted aspartyl proteases Sap. Various researchers specify a range of genes which contribute to adhesion, such as: CZF1, EFG1, TUP1, TPK1, TPK2, HGC1, RAS1, RIM101, VPS11, ECM1, CKA2, BCR1, BUD2, RSR1, IRS4, CHS2, SCS7, UBI4, UME6, TEC1 and GAT2. Influence for adherence have also heat shock proteins Hsp70, Mediator Middle domain subunit Med31 and morphological transition. Among factors affecting adhesion related to host cells it is necessary to mention fibronectins and integrins (receptors for Candida sp. adhesins), type of epithelial cells, their morphology and differentiation phase. To a lesser degree influence on adhesion have non-specific factors and environmental conditions.

Motivation of university and non-university stakeholders to change medical education in Vietnam

PubMed Central

Hoat, Luu Ngoc; Lan Viet, Nguyen; van der Wilt, GJ; Broerse, J; Ruitenberg, EJ; Wright, EP

2009-01-01

Background Both university and non-university stakeholders should be involved in the process of curriculum development in medical schools, because all are concerned with the competencies of the graduates. That may be difficult unless appropriate strategies are used to motivate each stakeholder. From 1999 to 2006, eight medical schools in Vietnam worked together to change the curriculum and teaching for general medical students to make it more community oriented. This paper describes the factors that motivated the different stakeholders to participate in curriculum change and teaching in Vietnamese medical schools and the activities to address those factors and have sustainable contributions from all relevant stakeholders. Methods Case study analysis of contributions to the change process, using reports, interviews, focus group discussions and surveys and based on Herzberg's Motivation Theory to analyze involvement of different stakeholders. Results Different stakeholders were motivated by selected activities, such as providing opportunities for non-university stakeholders to share their opinions, organizing interactions among university stakeholders, stimulating both bottom-up and top-down inputs, focusing on learning from each other, and emphasizing self-motivation factors. Conclusion The Herzberg Motivation theory helped to identify suitable approaches to ensure that teaching topics, materials and assessment methods more closely reflected the health care needs of the community. Other medical schools undertaking a reform process may learn from this experience. PMID:19630961

Epistatic Effects Contribute to Variation in BMD in Fischer 344 × Lewis F2 Rats

PubMed Central

Koller, Daniel L; Liu, Lixiang; Alam, Imranul; Sun, Qiwei; Econs, Michael J; Foroud, Tatiana; Turner, Charles H

2008-01-01

To further delineate the factors underlying the complex genetic architecture of BMD in the rat model, a genome screen for epistatic interactions was conducted. Several significant interactions were identified, involving both previously identified and novel QTLs. Introduction The variation in several of the risk factors for osteoporotic fracture, including BMD, has been shown to be caused largely by genetic differences. However, the genetic architecture of BMD is complex in both humans and in model organisms. We have previously reported quantitative trait locus (QTL) results for BMD from a genome screen of 595 female F2 progeny of Fischer 344 and Lewis rats. These progeny also provide an excellent opportunity to search for epistatic effects, or interaction between genetic loci, that contribute to fracture risk. Materials and Methods Microsatellite marker data from a 20-cM genome screen was analyzed along with weight-adjusted BMD (DXA and pQCT) phenotypic data using the R/qtl software package. Genotype and phenotype data were permuted to determine a genome-wide significance threshold for the epistasis or interaction LOD score corresponding to an α level of 0.01. Results and Conclusions Novel loci on chromosomes 12 and 15 showed a strong epistatic effect on total BMD at the femoral midshaft by pQCT (LOD = 5.4). A previously reported QTL on chromosome 7 was found to interact with a novel locus on chromosome 20 to affect whole lumbar BMD by pQCT (LOD = 6.2). These results provide new information regarding the mode of action of previously identified rat QTLs, as well as identifying novel loci that act in combination with known QTLs or with other novel loci to contribute to the risk factors for osteoporotic fracture. PMID:17907919

Does mental illness stigma contribute to adolescent standardized patients' discomfort with simulations of mental illness and adverse psychosocial experiences?

PubMed

Hanson, Mark D; Johnson, Samantha; Niec, Anne; Pietrantonio, Anna Marie; High, Bradley; MacMillan, Harriet; Eva, Kevin W

2008-01-01

Adolescent mental illness stigma-related factors may contribute to adolescent standardized patients' (ASP) discomfort with simulations of psychiatric conditions/adverse psychosocial experiences. Paradoxically, however, ASP involvement may provide a stigma-reduction strategy. This article reports an investigation of this hypothetical association between simulation discomfort and mental illness stigma. ASPs were randomly assigned to one of two simulation conditions: one was associated with mental illness stigma and one was not. ASP training methods included carefully written case simulations, educational materials, and active teaching methods. After training, ASPs completed the adapted Project Role Questionnaire to rate anticipated role discomfort with hypothetical adolescent psychiatric conditions/adverse psychosocial experiences and to respond to open-ended questions regarding this discomfort. A mixed design ANOVA was used to compare comfort levels across simulation conditions. Narrative responses to an open-ended question were reviewed for relevant themes. Twenty-four ASPs participated. A significant effect of simulation was observed, indicating that ASPs participating in the simulation associated with mental illness stigma anticipated greater comfort with portraying subsequent stigma-associated roles than did ASPs in the simulation not associated with stigma. ASPs' narrative responses regarding their reasons for anticipating discomfort focused upon the role of knowledge-related factors. ASPs' work with a psychiatric case simulation was associated with greater anticipated comfort with hypothetical simulations of psychiatric/adverse psychosocial conditions in comparison to ASPs lacking a similar work experience. The ASPs provided explanations for this anticipated discomfort that were suggestive of stigma-related knowledge factors. This preliminary research suggests an association between ASP anticipated role discomfort and mental illness stigma, and that ASP work may contribute to stigma reduction.

Methicillin-resistant food-related Staphylococcus aureus: a review of current knowledge and biofilm formation for future studies and applications.

PubMed

Doulgeraki, Agapi I; Di Ciccio, Pierluigi; Ianieri, Adriana; Nychas, George-John E

2017-01-01

There is increasing concern about the public health impact of methicillin-resistant Staphylococcus aureus. Food and animal are vectors of transmission, but the contribution of a contaminated environment is not well characterized. With regard to this, staphylococcal biofilms serve as a virulence factor, allowing MRSA strains to adhere to surfaces and other materials used in the food industry. Methicillin resistance and biofilm-forming capacity may contribute to the success of S. aureus as a human pathogen in both health care and community settings and the food production chain. This review summarizes current knowledge about the significance of food- and animal-derived MRSA strains and provides data on attachment and biofilm formation of MRSA. In addition, the impact of quorum sensing on MRSA gene expression and biofilm formation is examined. Copyright © 2016. Published by Elsevier Masson SAS.

Cells, Scaffolds and Their Interactions in Myocardial Tissue Regeneration.

PubMed

Gorabi, Armita Mahdavi; Tafti, Seyed Hossein Ahmadi; Soleimani, Masoud; Panahi, Yunes; Sahebkar, Amirhossein

2017-08-01

Cardiac regenerative therapy includes several techniques to repair and replace damaged tissues and organs using cells, biomaterials, molecules, or a combination of these factors. Generation of heart muscle is the most important challenge in this field, although it is well known that new advances in stem cell isolation and culture techniques in bioreactors and synthesis of bioactive materials contribute to the creation of cardiac tissue regeneration in vitro. Some investigations in stem cell biology shows that stem cells are an important source for regeneration of heart muscle cells and blood vessels and can thus clinically contribute to the regeneration of damaged heart tissue. The aim of this review was to explain the principles and challenges of myocardial tissue regeneration with an emphasis on stem cells and scaffolds. J. Cell. Biochem. 118: 2454-2462, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Precision and accuracy of luminescence lifetime-based phosphor thermometry: A case study of Eu(III):YSZ

NASA Astrophysics Data System (ADS)

Heeg, B.; Jenkins, T. P.

2013-09-01

Laser induced phosphor thermometry as a reliable technique requires an analysis of factors controlling or contributing to the precision and accuracy of a measurement. In this paper, we discuss several critical design parameters in the development of luminescence lifetime-based phosphor thermometry instrumentation for use at elevated temperatures such as encountered in hot sections of gas turbine engines. As precision is predominantly governed by signal and background photon shot noise and detector noise, a brief summary is presented of how these noise contributions may affect the measurement. Accuracy, on the other hand, is governed by a range of effects including, but not limited to, detector response characteristics, laser-induced effects, the photo-physics of the sensor materials, and also the method of data reduction. The various possible outcomes of measurement precision and accuracy are discussed with luminescence lifetime measurements on Eu(III):YSZ sensor coatings.

Superconducting cavity material for the European XFEL

NASA Astrophysics Data System (ADS)

Singer, W.; Singer, X.; Brinkmann, A.; Iversen, J.; Matheisen, A.; Navitski, A.; Tamashevich, Y.; Michelato, P.; Monaco, L.

2015-08-01

Analysis of the strategy for superconducting cavity material procurement and quality management is done on the basis of the experience with the cavity production for the European x-ray free electron laser (EXFEL) facility. An adjustment of the material specification to EXFEL requirements, procurement of material, quality control (QC), documentation, and shipment to cavity producers have been worked out and carried out by DESY. A multistep process of qualification of the material suppliers included detailed material testing, single- and nine-cell cavity fabrication, and cryogenic radiofrequency tests. Production of about 25 000 semi-finished parts of high purity niobium and niobium-titanium alloy in a period of three years has been divided finally between companies Heraeus, Tokyo Denkai, Ningxia OTIC, and PLANSEE. Consideration of large-grain (LG) material as a possible option for the EXFEL has resulted in the production of one cryogenic module consisting of seven (out of eight) LG cavities. LG materials fulfilled the EXFEL requirements and showed even 25% to 30% higher unloaded quality factor. A possible shortage of the required quantity of LG material on the market led, however, to the choice of conventional fine-grain (FG) material. Eddy-current scanning (ECS) has been applied as an additional QC tool for the niobium sheets and contributed significantly to the material qualification and sorting. Two percent of the sheets have been rejected, which potentially could affect up to one-third of the cavities. The main imperfections and defects in the rejected sheets have been analyzed. Samples containing foreign material inclusions have been extracted from the sheets and electrochemically polished. Some inclusions remained even after 150 μm surface layer removal. Indications of foreign material inclusions have been found in the industrially fabricated and treated cavities and a deeper analysis of the defects has been performed.

Nanoscale Thermoelectrics: A Study of the Absolute Seebeck Coefficient of Thin Films

NASA Astrophysics Data System (ADS)

Mason, Sarah J.

The worlds demand for energy is ever increasing. Likewise, the environmental impact of climate change due generating that energy through combustion of fossil fuels is increasingly alarming. Due to these factors new sources of renewable energies are constantly being sought out. Thermoelectric devices have the ability to generate clean, renewable, energy out of waste heat. However promising that is, their inefficiency severely inhibits applicability and practical use. The usefulness of a thermoelectric material increases with the dimensionless quantity, ZT, which depends on the Seebeck coefficient and electrical and thermal conductivity. These characteristic material parameters have interdependent energy transport contributions that classically prohibit the optimization of one with out the detriment of another. Encouraging advancements of ZT have occurred in the past ten years due to the decoupling of the thermal and electrical conductivity. Further advancements are necessary in order to produce applicable devices. One auspicious way of decoupling or tuning energy transport properties, is through size reduction to the nanoscale. However, with reduced dimensions come complications in measuring material properties. Measurements of properties such as the Seebeck coefficient, S, are primarily contingent upon the measurement apparatus. The Seebeck coefficient is defined as the amount of voltage generated by a thermal gradient. Measuring a thermally generated voltage by traditional methods gives, the voltage measured as a linear function of the Seebeck coefficient of the leads and of the material being tested divided by the applied thermal gradient. If accurate values of the Seebeck coefficients of the leads are available, simple subtraction provides the answer. This is rarely the case in nanoscale measurement devices with leads exclusively made from thin film materials that do not have well known bulk-like thermopower values. We have developed a technique to directly measure, S, as a function of temperature using a micro-machined thermal isolation platform consisting of a suspended, patterned SiN membrane. By measuring a series of thicknesses of metallic films up to the infinitely thin film limit, in which the electrical resistivity is no longer decreasing with increasing film thickness, but still not at bulk values, along with the effective electron mean free path, we are able to show the contribution of the leads needed to measure this property. Having a comprehensive understanding of the background contribution we are able to determine the absolute Seebeck coefficient of a wide variety of thin films. The nature of the design of the SiN membrane also allows the ability to accurately and directly measure thermal and electrical transport of the thin films yielding a comprehensive measurement of the three quantities that characterize a material's efficiency. This can serve to further the development of thermoelectric materials through precise measurements of the material properties that dictate efficiency.

A study of the relationship between microstructure and oxidation effects in nuclear graphite at very high temperatures

NASA Astrophysics Data System (ADS)

Lo, I.-Hsuan; Tzelepi, Athanasia; Patterson, Eann A.; Yeh, Tsung-Kuang

2018-04-01

Graphite is used in the cores of gas-cooled reactors as both the neutron moderator and a structural material, and traditional and novel graphite materials are being studied worldwide for applications in Generation IV reactors. In this study, the oxidation characteristics of petroleum-based IG-110 and pitch-based IG-430 graphite pellets in helium and air environments at temperatures ranging from 700 to 1600 °C were investigated. The oxidation rates and activation energies were determined based on mass loss measurements in a series of oxidation tests. The surface morphology was characterized by scanning electron microscopy. Although the thermal oxidation mechanism was previously considered to be the same for all temperatures higher than 1000 °C, the significant increases in oxidation rate observed at very high temperatures suggest that the oxidation behavior of the selected graphite materials at temperatures higher than 1200 °C is different. This work demonstrates that changes in surface morphology and in oxidation rate of the filler particles in the graphite materials are more prominent at temperatures above 1200 °C. Furthermore, possible intrinsic factors contributing to the oxidation of the two graphite materials at different temperature ranges are discussed taking account of the dominant role played by temperature.

Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

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

Dees, Craig

2016-07-01

A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevatedmore » ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.« less

Fiber Reinforced Composite Materials Used for Tankage

NASA Technical Reports Server (NTRS)

Cunningham, Christy

2005-01-01

The Nonmetallic Materials and Processes Group is presently working on several projects to optimize cost while providing effect materials for the space program. One factor that must be considered is that these materials must meet certain weight requirements. Composites contribute greatly to this effort. Through the use of composites the cost of launching payloads into orbit will be reduced to one-tenth of the current cost. This research project involved composites used for aluminum pressure vessels. These tanks are used to store cryogenic liquids during flight. The tanks need some type of reinforcement. Steel was considered, but added too much weight. As a result, fiber was chosen. Presently, only carbon fibers with epoxy resin are wrapped around the vessels as a primary source of reinforcement. Carbon fibers are lightweight, yet high strength. The carbon fibers are wet wound onto the pressure vessels. This was done using the ENTEC Filament Winding Machine. It was thought that an additional layer of fiber would aid in reinforcement as well as containment and impact reduction. Kevlar was selected because it is light weight, but five times stronger that steel. This is the same fiber that is used to make bullet-proof vests trampolines, and tennis rackets.

Probing the energy levels of perovskite solar cells via Kelvin probe and UV ambient pressure photoemission spectroscopy.

PubMed

Harwell, J R; Baikie, T K; Baikie, I D; Payne, J L; Ni, C; Irvine, J T S; Turnbull, G A; Samuel, I D W

2016-07-20

The field of organo-lead halide perovskite solar cells has been rapidly growing since their discovery in 2009. State of the art devices are now achieving efficiencies comparable to much older technologies like silicon, while utilising simple manufacturing processes and starting materials. A key parameter to consider when optimising solar cell devices or when designing new materials is the position and effects of the energy levels in the materials. We present here a comprehensive study of the energy levels present in a common structure of perovskite solar cell using an advanced macroscopic Kelvin probe and UV air photoemission setup. By constructing a detailed map of the energy levels in the system we are able to predict the importance of each layer to the open circuit voltage of the solar cell, which we then back up through measurements of the surface photovoltage of the cell under white illumination. Our results demonstrate the effectiveness of air photoemission and Kelvin probe contact potential difference measurements as a method of identifying the factors contributing to the open circuit voltage in a solar cell, as well as being an excellent way of probing the physics of new materials.

Kinetic characteristics of Cu (II) adsorption on nano(poly)-cumulene

NASA Astrophysics Data System (ADS)

Babkin, Alexander; Neskoromnaya, Elena; Burakova, Irina; Kucherova, Ananstasia; Burakov, Alexander; Mkrtchyan, Elina

2017-11-01

The present paper considers the possibility of using a new type of nanocarbon materials for sorption - polycumulene modified with "Taunit-M" carbon nanotubes or graphene nanoplatelets. To evaluate the efficiency of these novel nanomodified materials as sorbents, the following studies were carried out: 1) determination of the optimum pH value to perform static batch sorption experiments, 2) identification of the onset of equilibrium for the adsorption of heavy metal ions (on the example of Cu(II) ions), and 3) elucidation of kinetic adsorption mechanisms. As a result of implementation of kinetic models such as external and internal diffusion, as well as pseudo-first- and pseudo-second-order and Elovich (to determine the contribution of chemisorption), rate constants for the Cu(II) adsorption were estimated. It was noted that the absorption process occurs in a mixed-diffusion mode with the influence of the limiting factor - "sorbate-sorbate" chemical interaction. The equilibrium time was found to be 45 min at the sorption capacity values of about 30.71 mg g-1 (in the case of the material containing carbon nanotubes) and about 24.7 mg g-1 (in the case of the material containing graphene nanoplatelets).

Factors Contributing to Institutions Achieving Environmental Sustainability

ERIC Educational Resources Information Center

James, Matthew; Card, Karen

2012-01-01

Purpose: The purpose of this paper is to determine what factors contributed to three universities achieving environmental sustainability. Design/methodology/approach: A case study methodology was used to determine how each factor contributed to the institutions' sustainability. Site visits, fieldwork, document reviews, and interviews with…

Editorial

NASA Astrophysics Data System (ADS)

Sorger, Volker

2015-05-01

The year 2015 will likely have a unique place in the history books for the optics and photonics community, since it is paired with various events that are exciting for this field. For one it is the 125th birthday of the Optical Society (OSA), and in addition, the United Nations declared 2015 to be the Year Of Light. The first special issue of this year is dedicated to the topic of "Emerging Materials on Nanophotonics". While the field of nanophotonics has seen tremendous momentum through the support of plasmonics, opto-mechanics, and quantum photonics, it often are both the breakthroughs and continuing developments of materials that bring enabling opportunities for this field. For instance, the area of 2D materials has grown out of its infancy being focused on Graphene into a crossdisciplinary subject area. Here, both scientific and engineering potential are seen in a) novel physical effects, b) higher functionality, and c) smaller form factors all found in one material option. Coincidentally, theUSNational Science Foundation recently held a path findingworkshop on 2D materials Beyond Graphene, and followed through with a dedicated two-year program to fund engineering innovations of the same. Here, the bandgap tunability of trimetal Dichalcogenides (TMD) has found to bear rich bandgap tunability via composition, alloying, and altering design options such as substrate choices or stress, thus providing a large variety of functions. In this context it is interesting to note, that with the many material choices for TMDs, the importance of targeted approaches towards accelerated material-to-marketwas raised in theMaterial Genome Initiative by the US White House. However, with the fundamental challenge of nanophotonics - weak interactions between light and matter - the choice of materials as both device building block and functionality delivery option needs to be synergistically considered. In this regard metal optics is seen as an emerging field that is able to contribute to this design evolution of devices and systems with ever growing constrains. However, materials with new functionalities and *Corresponding Author: Volker Sorger: E-mail: sorger@email.gwu.edu form factors allow utilizing field enhancement techniques in an unprecedented way. This, for instance, enables subwavelength scale photonic and opto-electronic devices with performance improvements such as utilized by the Purcell effect in light emitters, detectors, or electro-optic switching devices. On the other hand, certain novel materials are able to clearly outperform any existing option; for instance transparent-conductive-oxides (TCO) have been found to be able to alter its refractive index by unity. Lastly, with the maturing of silicon photonics as an on-chip optics platform, higher integration options are considered in this special issue; passive devices such as waveguides made out of the electro-optically active Lithium Niobate aid highfunctionality systems on-chip. However, these novel materials and subsequent devices and systems need to be compared and benchmarked in order to be a guide for the next phase of opto-electronic integration and other technologies as carried out by some contributions of this special issue.As the festivities around this Year Of Light continue, this special issue summarizes some of the interesting work around the emerging materials for nanophotonics. Concluding, I would like to thank for the input and help of the fellow Guest Editors, Jenifer Dionne, Alexandra Boltasseva, and Luke Sweatlock along with the Nanophotonics staff, Dennis Couwenberg and Tara Dorrian. Sincerely

Warpage analysis in injection moulding process

NASA Astrophysics Data System (ADS)

Hidayah, M. H. N.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

2017-09-01

This study was concentrated on the effects of process parameters in plastic injection moulding process towards warpage problem by using Autodesk Moldflow Insight (AMI) software for the simulation. In this study, plastic dispenser of dental floss has been analysed with thermoplastic material of Polypropylene (PP) used as the moulded material and details properties of 80 Tonne Nessei NEX 1000 injection moulding machine also has been used in this study. The variable parameters of the process are packing pressure, packing time, melt temperature and cooling time. Minimization of warpage obtained from the optimization and analysis data from the Design Expert software. Integration of Response Surface Methodology (RSM), Center Composite Design (CCD) with polynomial models that has been obtained from Design of Experiment (DOE) is the method used in this study. The results show that packing pressure is the main factor that will contribute to the formation of warpage in x-axis and y-axis. While in z-axis, the main factor is melt temperature and packing time is the less significant among the four parameters in x, y and z-axes. From optimal processing parameter, the value of warpage in x, y and z-axis have been optimised by 21.60%, 26.45% and 24.53%, respectively.

Feasibility Studies of Palm Oil Mill Waste Aggregates for the Construction Industry

PubMed Central

Kanadasan, Jegathish; Ahmad Fauzi, Auni Filzah; Abdul Razak, Hashim; Selliah, Paramananthan; Subramaniam, Vijaya; Yusoff, Sumiani

2015-01-01

The agricultural industry in Malaysia has grown rapidly over the years. Palm oil clinker (POC) is a byproduct obtained from the palm oil industry. Its lightweight properties allows for its utilization as an aggregate, while in powder form as a filler material in concrete. POC specimens obtained throughout each state in Malaysia were investigated to evaluate the physical, chemical, and microstructure characteristics. Variations between each state were determined and their possible contributory factors were assessed. POC were incorporated as a replacement material for aggregates and their engineering characteristics were ascertained. Almost 7% of density was reduced with the introduction of POC as aggregates. A sustainability assessment was made through greenhouse gas emission (GHG) and cost factor analyses to determine the contribution of the addition of POC to the construction industry. Addition of POC helps to lower the GHG emission by 9.6% compared to control specimens. By channeling this waste into the construction industry, an efficient waste-management system can be promoted; thus, creating a cleaner environment. This study is also expected to offer some guides and directions for upcoming research works on the incorporation of POC. PMID:28793579

Overcoming low-alignment signal contrast induced alignment failure by alignment signal enhancement

NASA Astrophysics Data System (ADS)

Lee, Byeong Soo; Kim, Young Ha; Hwang, Hyunwoo; Lee, Jeongjin; Kong, Jeong Heung; Kang, Young Seog; Paarhuis, Bart; Kok, Haico; de Graaf, Roelof; Weichselbaum, Stefan; Droste, Richard; Mason, Christopher; Aarts, Igor; de Boeij, Wim P.

2016-03-01

Overlay is one of the key factors which enables optical lithography extension to 1X node DRAM manufacturing. It is natural that accurate wafer alignment is a prerequisite for good device overlay. However, alignment failures or misalignments are commonly observed in a fab. There are many factors which could induce alignment problems. Low alignment signal contrast is one of the main issues. Alignment signal contrast can be degraded by opaque stack materials or by alignment mark degradation due to processes like CMP. This issue can be compounded by mark sub-segmentation from design rules in combination with double or quadruple spacer process. Alignment signal contrast can be improved by applying new material or process optimization, which sometimes lead to the addition of another process-step with higher costs. If we can amplify the signal components containing the position information and reduce other unwanted signal and background contributions then we can improve alignment performance without process change. In this paper we use ASML's new alignment sensor (as was introduced and released on the NXT:1980Di) and sample wafers with special stacks which can induce poor alignment signal to demonstrate alignment and overlay improvement.

Time-Dependent Behavior of High-Strength Kevlar and Vectran Webbing

NASA Technical Reports Server (NTRS)

Jones, Thomas C.; Doggett, William R.

2014-01-01

High-strength Kevlar and Vectran webbings are currently being used by both NASA and industry as the primary load-bearing structure in inflatable space habitation modules. The time-dependent behavior of high-strength webbing architectures is a vital area of research that is providing critical material data to guide a more robust design process for this class of structures. This paper details the results of a series of time-dependent tests on 1-inch wide webbing including an initial set of comparative tests between specimens that underwent realtime and accelerated creep at 65 and 70% of their ultimate tensile strength. Variability in the ultimate tensile strength of the webbings is investigated and compared with variability in the creep life response. Additional testing studied the effects of load and displacement rate, specimen length and the time-dependent effects of preconditioning the webbings. The creep test facilities, instrumentation and test procedures are also detailed. The accelerated creep tests display consistently longer times to failure than their real-time counterparts; however, several factors were identified that may contribute to the observed disparity. Test setup and instrumentation, grip type, loading scheme, thermal environment and accelerated test postprocessing along with material variability are among these factors. Their effects are discussed and future work is detailed for the exploration and elimination of some of these factors in order to achieve a higher fidelity comparison.

Carrier concentration tuning in thermoelectric thiospinel Cu2CoTi3S8 by oxidative extraction of copper

NASA Astrophysics Data System (ADS)

Hashikuni, Katsuaki; Suekuni, Koichiro; Watanabe, Kosuke; Bouyrie, Yohan; Ohta, Michihiro; Ohtaki, Michitaka; Takabatake, Toshiro

2018-03-01

We report a method for carrier concentration tuning in the thermoelectric thiospinel Cu2CoTi3S8, which exhibits an n-type metallic character and a high power factor. An oxidative Cu extraction treatment produced Cu defects, resulting in Cu2-xCoTi3S8 up to x = 0.62. The electron carrier concentration was effectively reduced by this treatment, leading to the decrease in power factor, whereas the electronic contribution to the thermal conductivity was suppressed. As a result, the dimensionless figure of merit ZT remained unchanged as 0.2 at 670 K in the whole range of x ≤ 0.62. The oxidative Cu extraction described in this paper offers an opportunity to tune the electron carrier concentration for Cu-containing thermoelectric materials.

Thiol reductive stress induces cellulose-anchored biofilm formation in Mycobacterium tuberculosis

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

Trivedi, Abhishek; Mavi, Parminder Singh; Bhatt, Deepak

Mycobacterium tuberculosis (Mtb) forms biofilms harbouring antibiotic-tolerant bacilli in vitro, but the factors that induce biofilm formation and the nature of the extracellular material that holds the cells together are poorly understood. Here we show that intracellular thiol reductive stress (TRS) induces formation of Mtb biofilms in vitro, which harbour drug-tolerant but metabolically active bacteria with unchanged levels of ATP/ADP, NAD +/NADH and NADP +/NADPH. The development of these biofilms requires DNA, RNA and protein synthesis. Transcriptional analysis suggests that Mtb modulates only similar to 7% of its genes for survival in biofilms. In addition to proteins, lipids and DNA,more » the extracellular material in these biofilms is primarily composed of polysaccharides, with cellulose being a key component. Lastly, our results contribute to a better understanding of the mechanisms underlying Mtb biofilm formation, although the clinical relevance of Mtb biofilms in human tuberculosis remains unclear.« less

Observation of Solar Wind Charge Exchange Emission From Exospheric Material in and Outside Earth's Magnetosheath 2008 September 25

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Collier, M. R.; Cravens, T.; Kuntz, K. D.; Lepri, S. T.; Robertson, I.; Tomas, L.

2009-01-01

A long XMM-Newton exposure is used to observe solar wind charge exchange (SWCX) emission from exospheric material in and outside Earth's magnetosheath. The light curve of the O vii (0.5-0.62 keV) band is compared with a model for the expected emission, and while the emission is faint and the light curve has considerable scatter, the correlation is significant to better than 99.9%. This result demonstrates the validity of the geocoronal SWCX emission model for predicting a contribution to astrophysical observations to a scale factor of order unity (1.5). In addition, an average value of the SWCX O vii emission from the magnetosheath over the observation of 2.6 +/- 0.5 LU is derived. The results also demonstrate the potential utility of using X-ray observations to study global phenomena of the magnetosheath which currently are only investigated using in situ measurements.

Simple models for complex natural surfaces - A strategy for the hyperspectral era of remote sensing

NASA Technical Reports Server (NTRS)

Adams, John B.; Smith, Milton O.; Gillespie, Alan R.

1989-01-01

A two-step strategy for analyzing multispectral images is described. In the first step, the analyst decomposes the signal from each pixel (as expressed by the radiance or reflectance values in each channel) into components that are contributed by spectrally distinct materials on the ground, and those that are due to atmospheric effects, instrumental effects, and other factors, such as illumination. In the second step, the isolated signals from the materials on the ground are selectively edited, and recombined to form various unit maps that are interpretable within the framework of field units. The approach has been tested on multispectral images of a variety of natural land surfaces ranging from hyperarid deserts to tropical rain forests. Data were analyzed from Landsat MSS (multispectral scanner) and TM (Thematic Mapper), the airborne NS001 TM simulator, Viking Lander and Orbiter, AIS, and AVRIS (Airborne Visible and Infrared Imaging Spectrometer).

Thiol reductive stress induces cellulose-anchored biofilm formation in Mycobacterium tuberculosis

DOE PAGES

Trivedi, Abhishek; Mavi, Parminder Singh; Bhatt, Deepak; ...

2016-04-25

Mycobacterium tuberculosis (Mtb) forms biofilms harbouring antibiotic-tolerant bacilli in vitro, but the factors that induce biofilm formation and the nature of the extracellular material that holds the cells together are poorly understood. Here we show that intracellular thiol reductive stress (TRS) induces formation of Mtb biofilms in vitro, which harbour drug-tolerant but metabolically active bacteria with unchanged levels of ATP/ADP, NAD +/NADH and NADP +/NADPH. The development of these biofilms requires DNA, RNA and protein synthesis. Transcriptional analysis suggests that Mtb modulates only similar to 7% of its genes for survival in biofilms. In addition to proteins, lipids and DNA,more » the extracellular material in these biofilms is primarily composed of polysaccharides, with cellulose being a key component. Lastly, our results contribute to a better understanding of the mechanisms underlying Mtb biofilm formation, although the clinical relevance of Mtb biofilms in human tuberculosis remains unclear.« less

Targets of Online Hate: Examining Determinants of Victimization Among Young Finnish Facebook Users.

PubMed

Räsänen, Pekka; Hawdon, James; Holkeri, Emma; Keipi, Teo; Näsi, Matti; Oksanen, Atte

2016-01-01

Drawing from routine activity theory (RAT), this article seeks to determine the crucial factors contributing to youth victimization through online hate. Although numerous studies have supported RAT in an online context, research focusing on users of particular forms of social media is lacking. Using a sample of 15- to 18-year-old Finnish Facebook users (n = 723), we examine whether the risk of online hate victimization is more likely when youth themselves produced online hate material, visited online sites containing potentially harmful content, and deliberately sought out online hate material. In addition, we examine whether the risk of victimization is higher if respondents are worried about online victimization and had been personally victimized offline. The discussion highlights the accumulation of online and offline victimization, the ambiguity of the roles of victims and perpetrators, and the artificiality of the division between the online and offline environments among young people.

Social Exchange and Sexual Behavior in Young Women's Premarital Relationships in Kenya.

PubMed

Luke, Nancy; Goldberg, Rachel E; Mberu, Blessing U; Zulu, Eliya M

2011-10-01

Transactional sex, or the exchange of money and gifts for sexual activities within nonmarital relationships, has been widely considered a contributing factor to the disproportionate prevalence of HIV/AIDS among young women in sub-Saharan Africa. This study applied social exchange theory to premarital relationships in order to investigate the linkages between a variety of young women's resources-including employment and material transfers from male partners-and sexual behaviors. Data on the first month of premarital relationships (N=551 relationships) were collected from a random sample of young adult women ages 18-24 in Kisumu, Kenya, using a retrospective life history calendar. Consistent with the hypotheses, results showed that young women's income increases the likelihood of safer sexual activities, including delaying sex and using condoms consistently. Material transfers from the male partner displayed the opposite effect, supporting the view that resources obtained from within the relationship decrease young women's negotiating power.

Thiol reductive stress induces cellulose-anchored biofilm formation in Mycobacterium tuberculosis

PubMed Central

Trivedi, Abhishek; Mavi, Parminder Singh; Bhatt, Deepak; Kumar, Ashwani

2016-01-01

Mycobacterium tuberculosis (Mtb) forms biofilms harbouring antibiotic-tolerant bacilli in vitro, but the factors that induce biofilm formation and the nature of the extracellular material that holds the cells together are poorly understood. Here we show that intracellular thiol reductive stress (TRS) induces formation of Mtb biofilms in vitro, which harbour drug-tolerant but metabolically active bacteria with unchanged levels of ATP/ADP, NAD+/NADH and NADP+/NADPH. The development of these biofilms requires DNA, RNA and protein synthesis. Transcriptional analysis suggests that Mtb modulates only ∼7% of its genes for survival in biofilms. In addition to proteins, lipids and DNA, the extracellular material in these biofilms is primarily composed of polysaccharides, with cellulose being a key component. Our results contribute to a better understanding of the mechanisms underlying Mtb biofilm formation, although the clinical relevance of Mtb biofilms in human tuberculosis remains unclear. PMID:27109928

Thiol reductive stress induces cellulose-anchored biofilm formation in Mycobacterium tuberculosis.

PubMed

Trivedi, Abhishek; Mavi, Parminder Singh; Bhatt, Deepak; Kumar, Ashwani

2016-04-25

Mycobacterium tuberculosis (Mtb) forms biofilms harbouring antibiotic-tolerant bacilli in vitro, but the factors that induce biofilm formation and the nature of the extracellular material that holds the cells together are poorly understood. Here we show that intracellular thiol reductive stress (TRS) induces formation of Mtb biofilms in vitro, which harbour drug-tolerant but metabolically active bacteria with unchanged levels of ATP/ADP, NAD(+)/NADH and NADP(+)/NADPH. The development of these biofilms requires DNA, RNA and protein synthesis. Transcriptional analysis suggests that Mtb modulates only ∼7% of its genes for survival in biofilms. In addition to proteins, lipids and DNA, the extracellular material in these biofilms is primarily composed of polysaccharides, with cellulose being a key component. Our results contribute to a better understanding of the mechanisms underlying Mtb biofilm formation, although the clinical relevance of Mtb biofilms in human tuberculosis remains unclear.

Happiness and Satisfaction with Work Commute.

PubMed

Olsson, Lars E; Gärling, Tommy; Ettema, Dick; Friman, Margareta; Fujii, Satoshi

2013-03-01

Research suggests that for many people happiness is being able to make the routines of everyday life work, such that positive feelings dominate over negative feelings resulting from daily hassles. In line with this, a survey of work commuters in the three largest urban areas of Sweden show that satisfaction with the work commute contributes to overall happiness. It is also found that feelings during the commutes are predominantly positive or neutral. Possible explanatory factors include desirable physical exercise from walking and biking, as well as that short commutes provide a buffer between the work and private spheres. For longer work commutes, social and entertainment activities either increase positive affects or counteract stress and boredom. Satisfaction with being employed in a recession may also spill over to positive experiences of work commutes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11205-012-0003-2) contains supplementary material, which is available to authorized users.

Intrinsic dielectric properties of magnetodielectric La2CoMnO6

NASA Astrophysics Data System (ADS)

Silva, R. X.; Moreira, R. L.; Almeida, R. M.; Paniago, R.; Paschoal, C. W. A.

2015-06-01

Manganite with a double perovskite structure is an attractive material because of its interesting magnetoelectric and dielectric responses. In particular, colossal dielectric constant (CDC) behavior has been observed in La2CoMnO6 (LCMO) at radio frequencies and at room temperature. In this paper, we used infrared-reflectivity spectroscopy to study a LCMO ceramic obtained through a modified Pechini's method to determine the phonon contribution to the intrinsic dielectric response of the system and to investigate the CDC origin. The analysis of the main polar modes and of the obtained phonon parameters indicate that the CDC effect of LCMO is of pure extrinsic origin. In addition, we estimated the dielectric constant and the quality factor of the material in the microwave region to be ɛ's ˜ 16 and Qu × f ˜ 124 THz, which verifies that LCMO is appropriate for application in microwave devices and circuitry.

Teacher Implementation and the Impact of Game-Based Science Curriculum Materials

ERIC Educational Resources Information Center

Wilson, Christopher D.; Reichsman, Frieda; Mutch-Jones, Karen; Gardner, April; Marchi, Lisa; Kowalski, Susan; Lord, Trudi; Dorsey, Chad

2018-01-01

Research-based digital games hold great potential to be effective tools in supporting next-generation science learning. However, as with all instructional materials, teachers significantly influence their implementation and contribute to their effectiveness. To more fully understand the contributions and challenges of teacher implementation of…

Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities

NASA Astrophysics Data System (ADS)

Kneisel, P.; Ciovati, G.; Dhakal, P.; Saito, K.; Singer, W.; Singer, X.; Myneni, G. R.

2015-02-01

As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. Large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities made from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of Eacc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.

Review of ingot niobium as a material for superconducting radiofrequency accelerating cavities

DOE PAGES

Kneisel, P.; Ciovati, G.; Dhakal, P.; ...

2014-12-01

As a result of collaboration between Jefferson Lab and niobium manufacturer Companhia Brasileira de Metalurgia e Mineração (CBMM), ingot niobium was explored as a possible material for superconducting radiofrequency (SRF) cavity fabrication. The first single cell cavity from large-grain high purity niobium was fabricated and successfully tested at Jefferson Lab in 2004. This work triggered research activities in other SRF laboratories around the world. The large-grain (LG) niobium became not only an interesting alternative material for cavity builders, but also material scientists and surface scientists were eager to participate in the development of this technology. Many single cell cavities mademore » from material of different suppliers have been tested successfully and several multi-cell cavities have shown performances comparable to the best cavities made from standard fine-grain niobium. Several 9-cell cavities fabricated by Research Instruments and tested at DESY exceeded the best performing fine grain cavities with a record accelerating gradient of E acc=45.6 MV/m. The quality factor of those cavities was also higher than that of fine-grain (FG) cavities processed with the same methods. Such performance levels push the state-of-the art of SRF technology and are of great interest for future accelerators. This contribution reviews the development of ingot niobium technology and highlights some of the differences compared to standard FG material and opportunities for further developments.« less

High performance hydrogen storage from Be-BTB metal-organic framework at room temperature.

PubMed

Lim, Wei-Xian; Thornton, Aaron W; Hill, Anita J; Cox, Barry J; Hill, James M; Hill, Matthew R

2013-07-09

The metal-organic framework beryllium benzene tribenzoate (Be-BTB) has recently been reported to have one of the highest gravimetric hydrogen uptakes at room temperature. Storage at room temperature is one of the key requirements for the practical viability of hydrogen-powered vehicles. Be-BTB has an exceptional 298 K storage capacity of 2.3 wt % hydrogen. This result is surprising given that the low adsorption enthalpy of 5.5 kJ mol(-1). In this work, a combination of atomistic simulation and continuum modeling reveals that the beryllium rings contribute strongly to the hydrogen interaction with the framework. These simulations are extended with a thermodynamic energy optimization (TEO) model to compare the performance of Be-BTB to a compressed H2 tank and benchmark materials MOF-5 and MOF-177 in a MOF-based fuel cell. Our investigation shows that none of the MOF-filled tanks satisfy the United States Department of Energy (DOE) storage targets within the required operating temperatures and pressures. However, the Be-BTB tank delivers the most energy per volume and mass compared to the other material-based storage tanks. The pore size and the framework mass are shown to be contributing factors responsible for the superior room temperature hydrogen adsorption of Be-BTB.

Contribution of High Charge and Energy (HZE) Ions During Solar-Particle Event of September 29, 1989

NASA Technical Reports Server (NTRS)

Kim, Myung-Hee Y.; Wilson, John W.; Cucinotta, Francis A.; Simonsen, Lisa C.; Atwell, William; Badavi, Francis F.; Miller, Jack

1999-01-01

The solar-particle event (SPE) of September 29, 1989, produced an iron-rich spectrum with energies approaching 1 A GeV with an approximate spectral slope parameter of 2.5. These high charge and energy (HZE) ions challenge conventional methods of shield design and assessment of astronaut risks. In the past, shield design and risk assessment have relied on proton shielding codes and biological response models derived from X-ray and neutron exposure data. Because the HZE spectra decline rapidly with energy and HZE attenuation in materials is limited by their penetration power, details of the mass distributions about the sensitive tissues (shielding materials and the astronaut's body) are important determining factors of the exposure levels and distributions of linear energy transfer. Local tissue environments during the SPE of September 29, 1989, with its f= components are examined to analyze the importance of these ions to human SPE exposure. Typical space suit and lightly shielded structures leave significant contributions from HZE components to certain critical body tissues and have important implications on the models for risk assessment. A heavily shielded equipment room of a space vehicle or habitat requires knowledge of the breakup of these ions into lighter components, including neutrons, for shield design specifications.

Factors contributing to intervention fidelity in a multi-site chronic disease self-management program.

PubMed

Perrin, Karen M; Burke, Somer Goad; O'Connor, Danielle; Walby, Gary; Shippey, Claire; Pitt, Seraphine; McDermott, Robert J; Forthofer, Melinda S

2006-10-26

Disease self-management programs have been a popular approach to reducing morbidity and mortality from chronic disease. Replicating an evidence-based disease management program successfully requires practitioners to ensure fidelity to the original program design. The Florida Health Literacy Study (FHLS) was conducted to investigate the implementation impact of the Pfizer, Inc. Diabetes Mellitus and Hypertension Disease Self-Management Program based on health literacy principles in 14 community health centers in Florida. The intervention components discussed include health educator recruitment and training, patient recruitment, class sessions, utilization of program materials, translation of program manuals, patient retention and follow-up, and technical assistance. This report describes challenges associated with achieving a balance between adaptation for cultural relevance and fidelity when implementing the health education program across clinic sites. This balance was necessary to achieve effectiveness of the disease self-management program. The FHLS program was implemented with a high degree of fidelity to the original design and used original program materials. Adaptations identified as advantageous to program participation are discussed, such as implementing alternate methods for recruiting patients and developing staff incentives for participation. Effective program implementation depends on the talent, skill and willing participation of clinic staff. Program adaptations that conserve staff time and resources and recognize their contribution can increase program effectiveness without jeopardizing its fidelity.

Transparent conductors based on microscale/nanoscale materials for high performance devices

NASA Astrophysics Data System (ADS)

Gao, Tongchuan

Transparent conductors are important as the top electrode for a variety of optoelectronic devices, including solar cells, light-emitting diodes (LEDs), at panel displays, and touch screens. Doped indium tin oxide (ITO) thin films are the predominant transparent conductor material. However, ITO thin films are brittle, making them unsuitable for the emerging flexible devices, and suffer from high material and processing cost. In my thesis, we developed a variety of transparent conductors toward a performance comparable with or superior to ITO thin films, with lower cost and potential for scalable manufacturing. Metal nanomesh (NM), hierarchical graphene/metal microgrid (MG), and hierarchical metal NM/MG materials were investigated. Simulation methods were used as a powerful tool to predict the transparency and sheet resistance of the transparent conductors by solving Maxwell's equations and Poisson's equation. Affordable and scalable fabrication processes were developed thereafter. Transparent conductors with over 90% transparency and less than 10 O/square sheet resistance were successfully fabricated on both rigid and flexible substrates. Durability tests, such as bending, heating and tape tests, were carried out to evaluate the robustness of the samples. Haze factor, which characterizes how blurry a transparent conductor appears, was also studied in-depth using analytical calculation and numerical simulation. We demonstrated a tunable haze factor for metal NM transparent conductors and analyzed the principle for tuning the haze factor. Plasmonic effects, excited by some transparent conductors, can lead to enhanced performance in photovoltaic devices. We systematically studied the effect of incorporating metal NM into ultrathin film silicon solar cells using numerical simulation, with the aid of optimization algorithms to reduce the optimization time. Mechanisms contributing to the enhanced performance were then identified and analyzed. Over 72% enhancement in short-circuit current-density was demonstrated by the optimal solar cell compared with 300-nm-thick Si solar cell with antireflection coating and silver back reflector.

Computer-aided tissue engineering: benefiting from the control over scaffold micro-architecture.

PubMed

Tarawneh, Ahmad M; Wettergreen, Matthew; Liebschner, Michael A K

2012-01-01

Minimization schema in nature affects the material arrangements of most objects, independent of scale. The field of cellular solids has focused on the generalization of these natural architectures (bone, wood, coral, cork, honeycombs) for material improvement and elucidation into natural growth mechanisms. We applied this approach for the comparison of a set of complex three-dimensional (3D) architectures containing the same material volume but dissimilar architectural arrangements. Ball and stick representations of these architectures at varied material volumes were characterized according to geometric properties, such as beam length, beam diameter, surface area, space filling efficiency, and pore volume. Modulus, deformation properties, and stress distributions as contributed solely by architectural arrangements was revealed through finite element simulations. We demonstrated that while density is the greatest factor in controlling modulus, optimal material arrangement could result in equal modulus values even with volumetric discrepancies of up to 10%. We showed that at low porosities, loss of architectural complexity allows these architectures to be modeled as closed celled solids. At these lower porosities, the smaller pores do not greatly contribute to the overall modulus of the architectures and that a stress backbone is responsible for the modulus. Our results further indicated that when considering a deposition-based growth pattern, such as occurs in nature, surface area plays a large role in the resulting strength of these architectures, specifically for systems like bone. This completed study represents the first step towards the development of mathematical algorithms to describe the mechanical properties of regular and symmetric architectures used for tissue regenerative applications. The eventual goal is to create logical set of rules that can explain the structural properties of an architecture based solely upon its geometry. The information could then be used in an automatic fashion to generate patient-specific scaffolds for the treatment of tissue defects.

Proton induced target fragmentation studies on solid state nuclear track detectors using Carbon radiators

NASA Astrophysics Data System (ADS)

Szabó, J.; Pálfalvi, J. K.; Strádi, A.; Bilski, P.; Swakoń, J.; Stolarczyk, L.

2018-04-01

One of the limiting factors of an astronaut's career is the dose received from space radiation. High energy protons, being the main components of the complex radiation field present on a spacecraft, give a significant contribution to the dose. To investigate the behavior of solid state nuclear track detectors (SSNTDs) if they are irradiated by such particles, SSNTD stacks containing carbon blocks were exposed to high energy proton beams (70, 100, 150 and 230 MeV) at the Proteus cyclotron, IFJ PAN -Krakow. The incident protons cannot be detected directly; however, tracks of secondary particles, recoils and fragments of the constituent atoms of the detector material and of the carbon radiator are formed. It was found that as the proton energy increases, the number of tracks induced in the PADC material by secondary particles decreases. From the measured geometrical parameters of the tracks the linear energy transfer (LET) spectrum and the dosimetric quantities were determined, applying appropriate calibration. In the LET spectra the LET range of the most important secondary particles could be identified and their abundance showed differences in the spectra if the detectors were short or long etched. The LET spectra obtained on the SSNTDs irradiated by protons were compared to LET spectra of detectors flown on the International Space Station (ISS): they were quite similar, resulting in a quality factor difference of only 5%. Thermoluminescent detectors (TLDs) were applied in each case to measure the dose from primary protons and other lower LET particles present in space. Comparing and analyzing the results of the TLD and SSNTD measurements, it was obtained that proton induced target fragments contributed to the total absorbed dose in 3.2% and to the dose equivalent in 14.2% in this particular space experiment.

Primary Care Providers' HIV Prevention Practices Among Older Adults

PubMed Central

Davis, Tracy; Teaster, Pamela B.; Thornton, Alice; Watkins, John F.; Alexander, Linda; Zanjani, Faika

2016-01-01

Purpose To explore primary care providers' HIV prevention practices for older adults. Primary care providers' perceptions and awareness were explored to understand factors that affect their provision of HIV prevention materials and HIV screening for older adults. Design and Method Data were collected through 24 semistructured interviews with primary care providers (i.e., physicians, physician assistants, and nurse practitioners) who see patients older than 50 years. Results Results reveal facilitators and barriers of HIV prevention for older adults among primary care providers and understanding of providers' HIV prevention practices and behaviors. Individual, patient, institutional, and societal factors influenced HIV prevention practices among participants, for example, provider training and work experience, lack of time, discomfort in discussing HIV/AIDS with older adults, stigma, and ageism were contributing factors. Furthermore, factors specific to primary and secondary HIV prevention were identified, for instance, the presence of sexually transmitted infections influenced providers' secondary prevention practices. Implications HIV disease, while preventable, is increasing among older adults. These findings inform future research and interventions aimed at increasing HIV prevention practices in primary care settings for patients older than 50. PMID:25736425

Contributions of phase, sulfur vacancies, and edges to the hydrogen evolution reaction catalytic activity of porous molybdenum disulfide nanosheets

DOE PAGES

Yin, Ying; Han, Jiecai; Zhang, Yumin; ...

2016-06-07

Molybdenum disulfide (MoS 2) is a promising nonprecious catalyst for the hydrogen evolution reaction (HER) that has been extensively studied due to its excellent performance, but the lack of understanding of the factors that impact its catalytic activity hinders further design and enhancement of MoS 2-based electrocatalysts. Here, by using novel porous (holey) metallic 1T phase MoS 2 nanosheets synthesized by a liquid-ammonia-assisted lithiation route, we systematically investigated the contributions of crystal structure (phase), edges, and sulfur vacancies (S-vacancies) to the catalytic activity toward HER from five representative MoS 2 nanosheet samples, including 2H and 1T phase, porous 2H andmore » 1T phase, and sulfur-compensated porous 2H phase. Superior HER catalytic activity was achieved in the porous 1T phase MoS 2 nanosheets that have even more edges and S-vacancies than conventional 1T phase MoS 2. A comparative study revealed that the phase serves as the key role in determining the HER performance, as 1T phase MoS 2 always outperforms the corresponding 2H phase MoS 2 samples, and that both edges and S-vacancies also contribute significantly to the catalytic activity in porous MoS 2 samples. Then, using combined defect characterization techniques of electron spin resonance spectroscopy and positron annihilation lifetime spectroscopy to quantify the S-vacancies, the contributions of each factor were individually elucidated. Furthermore, this study presents new insights and opens up new avenues for designing electrocatalysts based on MoS 2 or other layered materials with enhanced HER performance.« less

Contributions of phase, sulfur vacancies, and edges to the hydrogen evolution reaction catalytic activity of porous molybdenum disulfide nanosheets

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

Yin, Ying; Han, Jiecai; Zhang, Yumin

Molybdenum disulfide (MoS 2) is a promising nonprecious catalyst for the hydrogen evolution reaction (HER) that has been extensively studied due to its excellent performance, but the lack of understanding of the factors that impact its catalytic activity hinders further design and enhancement of MoS 2-based electrocatalysts. Here, by using novel porous (holey) metallic 1T phase MoS 2 nanosheets synthesized by a liquid-ammonia-assisted lithiation route, we systematically investigated the contributions of crystal structure (phase), edges, and sulfur vacancies (S-vacancies) to the catalytic activity toward HER from five representative MoS 2 nanosheet samples, including 2H and 1T phase, porous 2H andmore » 1T phase, and sulfur-compensated porous 2H phase. Superior HER catalytic activity was achieved in the porous 1T phase MoS 2 nanosheets that have even more edges and S-vacancies than conventional 1T phase MoS 2. A comparative study revealed that the phase serves as the key role in determining the HER performance, as 1T phase MoS 2 always outperforms the corresponding 2H phase MoS 2 samples, and that both edges and S-vacancies also contribute significantly to the catalytic activity in porous MoS 2 samples. Then, using combined defect characterization techniques of electron spin resonance spectroscopy and positron annihilation lifetime spectroscopy to quantify the S-vacancies, the contributions of each factor were individually elucidated. Furthermore, this study presents new insights and opens up new avenues for designing electrocatalysts based on MoS 2 or other layered materials with enhanced HER performance.« less

[Methods of the multivariate statistical analysis of so-called polyetiological diseases using the example of coronary heart disease].

PubMed

Lifshits, A M

1979-01-01

General characteristics of the multivariate statistical analysis (MSA) is given. Methodical premises and criteria for the selection of an adequate MSA method applicable to pathoanatomic investigations of the epidemiology of multicausal diseases are presented. The experience of using MSA with computors and standard computing programs in studies of coronary arteries aterosclerosis on the materials of 2060 autopsies is described. The combined use of 4 MSA methods: sequential, correlational, regressional, and discriminant permitted to quantitate the contribution of each of the 8 examined risk factors in the development of aterosclerosis. The most important factors were found to be the age, arterial hypertension, and heredity. Occupational hypodynamia and increased fatness were more important in men, whereas diabetes melitus--in women. The registration of this combination of risk factors by MSA methods provides for more reliable prognosis of the likelihood of coronary heart disease with a fatal outcome than prognosis of the degree of coronary aterosclerosis.

Cultural and biological factors modulate spatial biases over development.

PubMed

Girelli, Luisa; Marinelli, Chiara Valeria; Grossi, Giuseppe; Arduino, Lisa S

2017-11-01

Increasing evidence supports the contribution of both biological and cultural factors to visuospatial processing. The present study adds to the literature by exploring the interplay of perceptual and linguistic mechanisms in determining visuospatial asymmetries in adults (Experiment 1) and children (Experiment 2). In particular, pre-schoolers (3 and 5 year-olds), school-aged children (8 year-old), and adult participants were required to bisect different types of stimuli, that is, lines, words, and figure strings. In accordance with the literature, results yielded a leftward bias for lines and words and a rightward bias for figure strings, in adult participants. More critically, different biases were found for lines, words, and figure strings in children as a function of age, reflecting the impact of both cultural and biological factors on the processing of different visuospatial materials. Specifically, an adult-like pattern of results emerged only in the older group of children (8 year-old), but not in pre-schoolers. Results are discussed in terms of literacy, reading habits exposure, and biological maturation.

Confidence level in venipuncture and knowledge on causes of in vitro hemolysis among healthcare professionals

PubMed Central

Milutinović, Dragana; Andrijević, Ilija; Ličina, Milijana; Andrijević, Ljiljana

2015-01-01

Introduction This study aimed to assess confidence level of healthcare professionals in venipuncture and their knowledge on the possible causes of in vitro hemolysis. Materials and methods A sample of 94 healthcare professionals (nurses and laboratory technicians) participated in this survey study. A four-section questionnaire was used as a research instrument comprising general information for research participants, knowledge on possible causes of in vitro hemolysis due to type of material used and venipuncture technique and specimen handling, as well as assessment of healthcare professionals’ confidence level in their own ability to perform first and last venipuncture. Results The average score on the knowledge test was higher in nurses’ than in laboratory technicians (8.11 ± 1.7, and 7.4 ± 1.5, respectively). The difference in average scores was statistically significant (P = 0.035) and Cohen’s d in the range of 0.4 indicates that there is a moderate difference on the knowledge test among the health care workers. Only 11/94 of healthcare professionals recognized that blood sample collection from cannula and evacuated tube is method which contributes most to the occurrence of in vitro hemolysis, whereas most risk factors affecting occurrence of in vitro hemolysis during venipuncture were recognized. There were no significant differences in mean score on the knowledge test in relation to the confidence level in venipuncture (P = 0.551). Conclusion Confidence level at last venipuncture among both profiles of healthcare staff was very high, but they showed insufficient knowledge about possible factors affecting hemolysis due to materials used in venipuncture compared with factors due to venipuncture technique and handling of blood sample. PMID:26527124

Revealing Sources and Distribution Changes of Dissolved Organic Matter (DOM) in Pore Water of Sediment from the Yangtze Estuary

PubMed Central

Wang, Ying; Zhang, Di; Shen, Zhenyao; Feng, Chenghong; Chen, Jing

2013-01-01

Dissolved organic matter (DOM) in sediment pore waters from Yangtze estuary of China based on abundance, UV absorbance, molecular weight distribution and fluorescence were investigated using a combination of various parameters of DOM as well as 3D fluorescence excitation emission matrix spectra (F-EEMS) with the parallel factor and principal component analysis (PARAFAC-PCA). The results indicated that DOM in pore water of Yangtze estuary was very variable which mainly composed of low aromaticity and molecular weight materials. Three humic-like substances (C1, C2, C4) and one protein-like substance (C3) were identified by PARAFAC model. C1, C2 and C4 exhibited same trends and were very similar. The separation of samples on both axes of the PCA showed the difference in DOM properties. C1, C2 and C4 concurrently showed higher positive factor 1 loadings, while C3 showed highly positive factor 2 loadings. The PCA analysis showed a combination contribution of microbial DOM signal and terrestrial DOM signal in the Yangtze estuary. Higher and more variable DOM abundance, aromaticity and molecular weight of surface sediment pore water DOM can be found in the southern nearshore than the other regions primarily due to the influence of frequent and intensive human activities and tributaries inflow in this area. The DOM abundance, aromaticity, molecular weight and fluorescence intensity in core of different depth were relative constant and increased gradually with depth. DOM in core was mainly composed of humic-like material, which was due to higher release of the sedimentary organic material into the porewater during early diagenesis. PMID:24155904

Origins of fine aerosol mass in the Baltimore-Washington corridor: implications from observation, factor analysis, and ensemble air parcel back trajectories

NASA Astrophysics Data System (ADS)

Antony Chen, L.-W.; Doddridge, Bruce G.; Dickerson, Russell R.; Chow, Judith C.; Henry, Ronald C.

Chemically speciated fine particulate matter (PM 2.5) and trace gases (including NH 3, HNO 3, CO, SO 2, NO y) have been sampled at Fort Meade (FME: 39.10°N, 76.74°W; elevation 46 m MSL), Maryland, since July 1999. FME is suburban, located in the middle of the Baltimore-Washington corridor, and generally downwind of the highly industrialized Midwest. The PM 2.5 at FME is expected to be of both local and regional sources. Measurements over a 2-year period include eight seasonally representative months. The PM 2.5 shows an annual mean of 13 μg m -3 and primarily consists of sulfate, nitrate, ammonium, and carbonaceous material. Day-to-day and seasonal variations in the PM 2.5 chemical composition reflect changes of contribution from various sources. UNMIX, an innovative receptor model, is used to retrieve potential sources of the PM 2.5. A six-factor model, including regional sulfate, local sulfate, wood smoke, copper/iron processing industry, mobile, and secondary nitrate, is constructed and compared with reported source emission profiles. The six factors are studied further using an ensemble back trajectory method to identify possible source locations. Sources of local sulfate, mobile, and secondary nitrate are more localized around the receptor than those of other factors. Regional sulfate and wood smoke are more regional and associated with westerly and southerly transport, respectively. This study suggests that the local contribution to PM 2.5 mass can vary from <30% in summer to >60% in winter.

Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels.

PubMed

Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

2016-11-15

Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH₂O EC-10, ECH₂O EC-20, ECH₂O EC-5, and ECH₂O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH₂O EC-5 and ECH₂O TE, which also performed surprisingly well in saline conditions.

Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels

PubMed Central

Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

2016-01-01

Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH2O EC-10, ECH2O EC-20, ECH2O EC-5, and ECH2O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH2O EC-5 and ECH2O TE, which also performed surprisingly well in saline conditions. PMID:27854263

The global metabolic transition: Regional patterns and trends of global material flows, 1950–2010

PubMed Central

Schaffartzik, Anke; Mayer, Andreas; Gingrich, Simone; Eisenmenger, Nina; Loy, Christian; Krausmann, Fridolin

2014-01-01

Since the World War II, many economies have transitioned from an agrarian, biomass-based to an industrial, minerals-based metabolic regime. Since 1950, world population grew by factor 2.7 and global material consumption by factor 3.7–71 Gigatonnes per year in 2010. The expansion of the resource base required by human societies is associated with growing pressure on the environment and infringement on the habitats of other species. In order to achieve a sustainability transition, we require a better understanding of the currently ongoing metabolic transition and its potential inertia. In this article, we present a long-term global material flow dataset covering material extraction, trade, and consumption of 177 individual countries between 1950 and 2010. We trace patterns and trends in material flows for six major geographic and economic country groupings and world regions (Western Industrial, the (Former) Soviet Union and its allies, Asia, the Middle East and Northern Africa, Latin America and the Caribbean, and Sub-Saharan Africa) as well as their contribution to the emergence of a global metabolic profile during a period of rapid industrialization and globalization. Global average material use increased from 5.0 to 10.3 tons per capita and year (t/cap/a) between 1950 and 2010. Regional metabolic rates range from 4.5 t/cap/a in Sub-Saharan Africa to 14.8 t/cap/a in the Western Industrial grouping. While we can observe a stabilization of the industrial metabolic profile composed of relatively equal shares of biomass, fossil energy carriers, and construction minerals, we note differences in the degree to which other regions are gravitating toward a similar form of material use. Since 2000, Asia has overtaken the Western Industrial grouping in terms of its share in global resource use although not in terms of its per capita material consumption. We find that at a sub-global level, the roles of the world regions have changed. There are, however, no signs yet that this will lead to stabilization or even a reduction of global resource use. PMID:25844026

The morphology and chronology of a landslide near Dillon Dam, Dillon, Colorado

USGS Publications Warehouse

Wahlstrom, E.E.; Nichols, T.C.

1969-01-01

Investigations were made of a landslide at the Dillon Dam site, Dillon, Colo., that included detailed laboratory and field analyses of the mineralogy, chemistry, and physical properties of landslide materials and the bedrock formations from which they were derived. These investigations provide an understanding of the relative importance of various factors contributing to the origin and reactivation of a landslide in overburden resting on the Morrison Formation. The landslide material consists dominantly of an aggregate of large to small angular fragments of quartzite and sandstone from the Dakota Formation, embedded in a matrix of very fine grained to colloidal clayey substances derived mainly from the upper, noncalcareous portion of the Morrison Formation. During construction of Dillon Dam and associated structures, excavation of the toe of an old, relatively stable landslide adjacent to the left abutment caused renewed movement that threatened engulfment of the intake structure at the portal of the diversion tunnel for the reservoir. Remedial measures included excavation of a large volume of the landslide material and construction of a gravel-fill coffer- dam on bedrock at the toe of the landslide. ?? 1969.

Waffle Production: Influence of Baking Plate Material on Sticking of Waffles.

PubMed

Huber, Regina; Kalss, Georg; Schoenlechner, Regine

2017-01-01

Background of this study was to understand the factors that contribute to sticking of fresh egg waffles on baking plates. The aim of this study was to investigate the sticking (adhesion) behavior of waffles on 4 different baking plate materials (ductile iron, grey iron, low alloyed steel, and steel with titanium nitrite coating) at different baking parameters (temperature and time) and application of 3 different release agents (different fat compositions). Baking plates from ductile and grey iron showed lower release properties of waffles than the 2 steel baking plates. Baking parameters had to be high enough to allow rapid product crust formation but prevent burning, which again increases sticking behavior. Release agents based on short-chain fatty acids with higher degree of saturation provided better release behavior of waffles than those based on long-chain fatty acids or on emulsifier-acid combinations. Baking plates with increased hardness, good heat storage capacity, and smooth surface seemed to be best suitable. Further research on appropriate coating material might be promising for future. © 2016 Institute of Food Technologists®.

Tube Formation in Nanoscale Materials

PubMed Central

2008-01-01

The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities. PMID:20592945

Light-induced defects in hybrid lead halide perovskite

NASA Astrophysics Data System (ADS)

Sharia, Onise; Schneider, William

One of the main challenges facing organohalide perovskites for solar application is stability. Solar cells must last decades to be economically viable alternatives to traditional energy sources. While some causes of instability can be avoided through engineering, light-induced defects can be fundamentally limiting factor for practical application of the material. Light creates large numbers of electron and hole pairs that can contribute to degradation processes. Using ab initio theoretical methods, we systematically explore first steps of light induced defect formation in methyl ammonium lead iodide, MAPbI3. In particular, we study charged and neutral Frenkel pair formation involving Pb and I atoms. We find that most of the defects, except negatively charged Pb Frenkel pairs, are reversible, and thus most do not lead to degradation. Negative Pb defects create a mid-gap state and localize the conduction band electron. A minimum energy path study shows that, once the first defect is created, Pb atoms migrate relatively fast. The defects have two detrimental effects on the material. First, they create charge traps below the conduction band. Second, they can lead to degradation of the material by forming Pb clusters.

78 FR 42584 - Additional Designation of Aluminat, Pars Amayesh Sanaat Kish, Parviz Khaki, Pishro Systems...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... Order 13382, ``Blocking Property of Weapons of Mass Destruction Proliferators and Their Supporters... materially contributed to, or pose a risk of materially contributing to, the proliferation of weapons of mass destruction or their means of delivery (including missiles capable of delivering such weapons), including any...

The contribution of phosphate–phosphate repulsions to the free energy of DNA bending

PubMed Central

Range, Kevin; Mayaan, Evelyn; Maher, L. J.; York, Darrin M.

2005-01-01

DNA bending is important for the packaging of genetic material, regulation of gene expression and interaction of nucleic acids with proteins. Consequently, it is of considerable interest to quantify the energetic factors that must be overcome to induce bending of DNA, such as base stacking and phosphate–phosphate repulsions. In the present work, the electrostatic contribution of phosphate–phosphate repulsions to the free energy of bending DNA is examined for 71 bp linear and bent-form model structures. The bent DNA model was based on the crystallographic structure of a full turn of DNA in a nucleosome core particle. A Green's function approach based on a linear-scaling smooth conductor-like screening model was applied to ascertain the contribution of individual phosphate–phosphate repulsions and overall electrostatic stabilization in aqueous solution. The effect of charge neutralization by site-bound ions was considered using Monte Carlo simulation to characterize the distribution of ion occupations and contribution of phosphate repulsions to the free energy of bending as a function of counterion load. The calculations predict that the phosphate–phosphate repulsions account for ∼30% of the total free energy required to bend DNA from canonical linear B-form into the conformation found in the nucleosome core particle. PMID:15741179

Transport of Riverine Material From Multiple Rivers in the Chesapeake Bay: Important Control of Estuarine Circulation on the Material Distribution

NASA Astrophysics Data System (ADS)

Du, Jiabi; Shen, Jian

2017-11-01

Driven by estuarine circulation, material released from lower Chesapeake Bay tributaries has the potential to be transported to the upper Bay. How far and what fraction of the material from tributaries can be carried to the upper estuary have not been quantitatively investigated. For an estuary system with multiple tributaries, the relative contribution from each tributary can provide valuable information for source assessment and fate prediction for riverine materials and passive moving organisms. We conducted long-term numerical simulations using multiple passive tracers that are independently released in the headwater of five main rivers (i.e., Susquehanna, Potomac, Rappahannock, York, and James Rivers) and calculated the relative contribution of each river to the total material in the mainstem. The results show that discharge from Susquehanna River exerts the dominant control on the riverine material throughout the entire mainstem. Despite the smaller contribution from the lower-middle Bay tributaries to the total materials in the mainstem, materials released from these rivers have a high potential to be transported to the middle-upper Bay through the bottom inflow by the persistent estuarine circulation. The fraction of the tributary material transported to the upper Bay depends on the location of the tributary. Materials released near the mouth are subject to a rapid flushing process, small retention time, and strong shelf current. Our results reveal three distinct spatial patterns for materials released from the main river, tributary, and coastal oceans. This study highlights the important control of estuarine circulation over horizontal and vertical distributions of materials in the mainstem.

Background PM2.5 source apportionment in the remote Northwestern United States

NASA Astrophysics Data System (ADS)

Hadley, Odelle L.

2017-10-01

This study used the Environmental Protection Agency's positive matrix factorization model (EPA PMF5.0) to identify five primary source factors contributing to the ambient PM2.5 concentrations at Cheeka Peak Atmospheric Observatory (CPO), Neah Bay WA between January 2011 and December 2014. CPO is home to both an IMPROVE (Interagency Monitoring for Protected Visual Environments) and a NCore multi-pollutant monitoring site. Chemically resolved particulate data from the IMPROVE site was the input data to EPA PMF5.0 and the resulting source factors were derived solely from these data. Solutions from the model were analyzed in context with trace gas and meteorological data collected at the NCore site located roughly 10 m away. Seasonal and long-term trends were analyzed for all five factors and provide the first complete source apportionment analysis of PM2.5 at this remote location. The first factor, identified as marine-traffic residual fuel oil (RFO), was the highest contributor to PM2.5 during late summer. Over the 4-year analysis, the RFO percent contribution to total PM2.5 declined. This is consistent with previous studies and may be attributed to regulations restricting the sulfur content of ship fuel. Biomass combustion emissions (BMC) and sea salt were the largest PM2.5 sources observed at CPO in winter, accounting for over 80% of the fine particulate. BMC accounted for a large percent of the fine particulate pollution when winds were easterly, or continental. Sea salt was the dominant winter factor when winds blew from the west. Measured trace carbon monoxide (CO) and reactive nitrogen species (NOy) were most strongly correlated with the BMC factor and continental winds. The fourth factor was identified as aged crustal material, or dust. In all three years, dust peaked in the spring and was associated exclusively with north-easterly winds. The last factor was identified as aged sea salt mixed with nitrate, sulfate, and other components common to RFO and BMC source factors. It did not exhibit a strong seasonal cycle or dependence on wind direction.

EMISSION OF ORGANIC SUBSTANCES FROM INDOOR SURFACE MATERIALS

EPA Science Inventory

A wide variety of surface materials in buildings can release organic compounds. Examples include building materials, furnishings, maintenance materials, clothing, and paper products. These sources contribute substantially to the hundreds of organic compounds that have been measur...

Bending efficiency through property gradients in bamboo, palm, and wood-based composites.

PubMed

Wegst, Ulrike G K

2011-07-01

Nature, to a greater extent than engineering, takes advantage of hierarchical structures. These allow for optimization at each structural level to achieve mechanical efficiency, meaning mechanical performance per unit mass. Palms and bamboos do this exceptionally well; both are fibre-reinforced cellular materials in which the fibres are aligned parallel to the stem or culm, respectively. The distribution of these fibres is, however, not uniform: there is a density and modulus gradient across the section. This property gradient increases the flexural rigidity of the plants per unit mass, mass being a measure of metabolic investment made into an organism's construction. An analytical model is presented with which a 'gradient shape factor' can be calculated that describes by how much a plant's bending efficiency is increased through gradient structures. Combining the 'gradient shape factor' with a 'microstructural shape factor' that captures the efficiency gained through the cellular nature of the fibre composite's matrix, and a 'macroscopical shape factor' with which the tubular shape of bamboo can be described, for example, it is possible to explore how much each of these three structural levels of the hierarchy contributes to the overall bending performance of the stem or culm. In analogy, the bending efficiency of the commonly used wood-based composite medium-density fibreboard can be analysed; its property gradient is due to its manufacture by hot pressing. A few other engineered materials exist that emulate property gradients; new manufacturing routes to prepare them are currently being explored. It appears worthwhile to pursue these further. Copyright © 2011. Published by Elsevier Ltd.

Produsage in a/synchronous learner-led e-learning

NASA Astrophysics Data System (ADS)

Kazmer, Michelle M.

2011-04-01

Creating a successful produsage environment for a required course taught via e-learning requires analyzing various factors: the learning context, learner-led education in required classes, the structure of the class, and reflections and evaluations of each semester's iteration of the course. Taking a produsage perspective, this paper analyzes the long-term development of a required graduate-level course in information organization. The course is examined closely to show how its materials, assignments, technology, instruction, and culture contribute to a learner-led produsage environment and lasting knowledge creation. The analysis leads to implications for course design and working with learners to create knowledge that may be applied in multiple settings.

Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying

NASA Astrophysics Data System (ADS)

Nosenko, Valentyna; Strutynska, Nataliia; Vorona, Igor; Zatovsky, Igor; Dzhagan, Volodymyr; Lemishko, Sergiy; Epple, Matthias; Prymak, Oleg; Baran, Nikolai; Ishchenko, Stanislav; Slobodyanik, Nikolai; Prylutskyy, Yuriy; Klyui, Nickolai; Temchenko, Volodymyr

2015-12-01

Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated hydroxyapatite powder. The coatings consisted of tetracalcium phosphate and apatite. The ratio depended slightly on the degree of crystallinity of the initial powder and processing parameters of the coating preparation. The tetracalcium phosphate phase was homogeneous; the apatite phase contained defects localized on the sixfold axis and consisted of hydroxyapatite and oxyapatite. Technological factors contributing to the transformation of hydroxyapatite powder structure during coating formation by detonation spraying are discussed.

Habitat geology studies on and near Georges Bank, off New England

USGS Publications Warehouse

Valentine, P.C.

2001-01-01

Marine habitat geology is the study of the distribution of geologic materials that form the seabed, the geologic processes (such as sediment movement and deposition) that affect the seabed, and the interplay of geologic factors and species behavior that gives rise to biological habitats in general and to specific habitats deemed essential to the success of a particular species (essential fish habitats, EFH's). Georges Bank was once the premier East Coast fishing ground for groundfish and scallops. The decline of groundfish species due to overfishing contributed to the increasingly restrictive management of fish stocks and a need to identify and protect EFH's.

Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying.

PubMed

Nosenko, Valentyna; Strutynska, Nataliia; Vorona, Igor; Zatovsky, Igor; Dzhagan, Volodymyr; Lemishko, Sergiy; Epple, Matthias; Prymak, Oleg; Baran, Nikolai; Ishchenko, Stanislav; Slobodyanik, Nikolai; Prylutskyy, Yuriy; Klyui, Nickolai; Temchenko, Volodymyr

2015-12-01

Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated hydroxyapatite powder. The coatings consisted of tetracalcium phosphate and apatite. The ratio depended slightly on the degree of crystallinity of the initial powder and processing parameters of the coating preparation. The tetracalcium phosphate phase was homogeneous; the apatite phase contained defects localized on the sixfold axis and consisted of hydroxyapatite and oxyapatite. Technological factors contributing to the transformation of hydroxyapatite powder structure during coating formation by detonation spraying are discussed.

[Biosecurity and clinical care nursing: contributions for the promotion of worker's health].

PubMed

Gallas, Samanta Rauber; Fontana, Rosane Teresinha

2010-01-01

Qualitative study that aimed at investigating concepts and practices of nursing technicians on biosecurity and its interface with biological hazards, with 20 workers developed a clinical care unit of a hospital in the interior of Rio Grande do Sul. Data were collected through interviews and systematic observation. Thematic analysis was the methodology used for data processing. The negligence of its employees on the use of individual protection equipment and work overload are risk factors for accidents with biological material. Suggested that partnerships between the actors involved in caring for the construction of healthy environments and accountability for negligence on biosecurity.

[Research on China railway health campaign in 1930s].

PubMed

Huang, Huaping

2015-01-01

The motivation factors of China's railway health campaign in 1930s included avocation by the government, mass media mobilization, railway authorities' hygiene awareness and the systematization of the construction of organization. During the health campaign, the railway authorities adopted various approaches for its formation, including the rally speeches, distribution of materials, cleaning and vaccination etc. Unfortunately, the actual effect of railway health campaign was not satisfactory, yet, it enhanced theoretically railway employees' health knowledge and contributed to the promotion of modernization of hygienic knowledge. Meanwhile, there still existed many problems in the railway health campaign, for example, lack of funds, formalism and uneven development among the railway bureaus.

Analysis on fuel breeding capability of FBR core region based on minor actinide recycling doping

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

Permana, Sidik; Novitrian,; Waris, Abdul

Nuclear fuel breeding based on the capability of fuel conversion capability can be achieved by conversion ratio of some fertile materials into fissile materials during nuclear reaction processes such as main fissile materials of U-233, U-235, Pu-239 and Pu-241 and for fertile materials of Th-232, U-238, and Pu-240 as well as Pu-238. Minor actinide (MA) loading option which consists of neptunium, americium and curium will gives some additional contribution from converted MA into plutonium such as conversion Np-237 into Pu-238 and it's produced Pu-238 converts to Pu-239 via neutron capture. Increasing composition of Pu-238 can be used to produce fissilemore » material of Pu-239 as additional contribution. Trans-uranium (TRU) fuel (Mixed fuel loading of MOX (U-Pu) and MA composition) and mixed oxide (MOX) fuel compositions are analyzed for comparative analysis in order to show the effect of MA to the plutonium productions in core in term of reactor criticality condition and fuel breeding capability. In the present study, neptunium (Np) nuclide is used as a representative of MAin trans-uranium (TRU) fuel composition as Np-MOX fuel type. It was loaded into the core region gives significant contribution to reduce the excess reactivity in comparing to mixed oxide (MOX) fuel and in the same time it contributes to increase nuclear fuel breeding capability of the reactor. Neptunium fuel loading scheme in FBR core region gives significant production of Pu-238 as fertile material to absorp neutrons for reducing excess reactivity and additional contribution for fuel breeding.« less

Enhanced bioactive scaffolds for bone tissue regeneration

NASA Astrophysics Data System (ADS)

Karnik, Sonali

Bone injuries are commonly termed as fractures and they vary in their severity and causes. If the fracture is severe and there is loss of bone, implant surgery is prescribed. The response to the implant depends on the patient's physiology and implant material. Sometimes, the compromised physiology and undesired implant reactions lead to post-surgical complications. [4, 5, 20, 28] Efforts have been directed towards the development of efficient implant materials to tackle the problem of post-surgical implant failure. [ 15, 19, 24, 28, 32]. The field of tissue engineering and regenerative medicine involves the use of cells to form a new tissue on bio-absorbable or inert scaffolds. [2, 32] One of the applications of this field is to regenerate the damaged or lost bone by using stem cells or osteoprogenitor cells on scaffolds that can integrate in the host tissue without causing any harmful side effects. [2, 32] A variety of natural, synthetic materials and their combinations have been used to regenerate the damaged bone tissue. [2, 19, 30, 32, 43]. Growth factors have been supplied to progenitor cells to trigger a sequence of metabolic pathways leading to cellular proliferation, differentiation and to enhance their functionality. [56, 57] The challenge persists to supply these proteins, in the range of nano or even picograms, and in a sustained fashion over a period of time. A delivery system has yet to be developed that would mimic the body's inherent mechanism of delivering the growth factor molecules in the required amount to the target organ or tissue. Titanium is the most preferred metal for orthopedic and orthodontic implants. [28, 46, 48] Even though it has better osteogenic properties as compared to other metals and alloys, it still has drawbacks like poor integration into the surrounding host tissue leading to bone resorption and implant failure. [20, 28, 35] It also faces the problem of postsurgical infections that contributes to the implant failure. [26, 37]. The focus of this dissertation was to design and develop novel implant materials for coating titanium to improve its biological properties. These natural and/or semi-synthetic materials improved cellular adhesion, biological response to the scaffolds and prevented growth of bacteria when they were enhanced with growth factor and anti-infective loaded nanotubes. The implant materials showed promise when tested in vitro for cell proliferation, differentiation and bacterial growth inhibition.

Timber - Material of the Future - Examples of Small Wooden Architectural Structures

NASA Astrophysics Data System (ADS)

Żmijewki, Tomasz; Wojtowicz-Jankowska, Dorota

2017-10-01

The aim of this article is to present various types of wood-based products, classified as engineered timber, while specifying the implications of their structural properties for their forms. Timber is used as a construction material due to its fire resistance, good structural characteristics and insulating properties. The advent of new technologies of wood processing and wood-based materials production has converted timber into a high-tech material, thus encouraging the architects to consider it ever more often in their projects. As wooden technologies overcome constraints, timber begins to compete with steel and concrete. The design characteristics of new wood-based products allow wooden structures to be higher, have larger spans, and more diverse forms than ever. Wood-based materials include materials made of solid wood, veneers, strand, and wood which, due to its inferior quality, would otherwise be unfit for constructions. Elements and layers of these products are glued using different kinds of strong and water-resistant adhesives. The article presents the history of development of new wood technologies, discussing increasingly popular wood-based materials such as glued laminated timber, cross-laminated timber, or structural composite lumber. The paper analyses their technical and fire-resistance properties, and points to ecological aspect, as factors contributing to the growing popularity of these materials. Finally, the timber’s characteristics are contrasted with those of steel and concrete. The article lists examples of wooden objects representing the so-called small architecture structures from across Europe. They illustrate the potential, the uniqueness and the versatility that wood-based materials offer for constructors and architects. All these features form sufficient grounds for stating that timber truly is a construction material of the 21st century.

EPA Positive Matrix Factorization (PMF) 5.0 Fundamentals and User Guide

EPA Science Inventory

PMF is a multivariate factor analysis tool that decomposes a matrix of speciated sample data into two matrices: factor contributions (G) and factor profiles (F). These factor profiles need to be interpreted by the user to identify the source types that may be contributing to the ...

Interrelation of Entropic Contributors to π -Stacking in Solution

NASA Astrophysics Data System (ADS)

Starodub, Maria A.; Lantushenko, Anastasia O.; Evstigneev, Vladislav P.; Golovchenko, Igor V.; Mykhina, Yulia V.; Savin, Valery V.; Evstigneev, Maxim P.

2016-08-01

The recently published most complete set of thermodynamical data on self- and hetero-complexation of aromatic molecules measured under comparable experimental conditions were analyzed. The main aim of this study is to get insights into contribution of various entropic factors to π -stacking in aqueous solution. It was found that the experimental entropy change on π -stacking is determined by counterbalancing effects of two principal factors, i.e., the hydrophobic interaction (positive contribution) and the loss of degrees of freedom (negative contribution) modulated by the electrostatic contribution. Other factors, including the mixing entropy contribution, were shown to be less important.

Children's Freedom: A. S. Neill and the Evolution of the Summerhill Idea.

ERIC Educational Resources Information Center

Hemmings, Ray

This book is a critical evaluation of A. S. Neill's contribution to educational theory and practice. The study includes some biographical material, but this material is introduced to provide a focus for Neill's ideas. The author devotes special attention to Neill's contributions to the psychological aspects of freedom within the social and…

Next Generation Anodes for Lithium-Ion Batteries: Thermodynamic Understanding and Abuse Performance

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

Fenton, Kyle R.; Allcorn, Eric; Nagasubramanian, Ganesan

The objectives of this report are as follows: elucidate degradation mechanisms, decomposition products, and abuse response for next generation silicon based anodes; and Understand the contribution of various materials properties and cell build parameters towards thermal runaway enthalpies. Quantify the contributions from particle size, composition, state of charge (SOC), electrolyte to active materials ratio, etc.

Prenatal and familial factors of caries in first permanent molars in schoolchildren living in urban area of Łódź, Poland.

PubMed

Borowska-Strugińska, Beata; Żądzińska, Elżbieta; Bruzda-Zwiech, Agnieszka; Filipińska, Renata; Lubowiecka-Gontarek, Beata; Szydłowska-Walendowska, Beata; Wochna-Sobańska, Magdalena

2016-06-01

The objective of the present work is to identify the set of prenatal and familial factors that contribute to dental caries of first permanent molars in preschool and young schoolchildren, which will make it possible to determine a high-risk group that should be considered for special preventive measures. This study contributes to the evidence for the multifactorial nature of dental caries. Material was collected during a 2009-2010 study conducted in randomly selected schools and kindergartens in the city of Łódź (Poland). Only children with first permanent molars present were considered for the analysis, which limited the database to 1131 children. Dental examinations were accompanied by a questionnaire completed by the parents, covering items pertaining to prenatal and familial determinants. The present study shows that there are significant differences in the prevalence of caries in first molars between children of different ages (5-13 lat) and that no such differences exist between boys and girls. The prenatal and familial factors conducive to caries include maternal education level (OR=0.55), mode of delivery (OR=0.63) and birth order (OR=0.63). Mothers' smoking habit is also associated with increased caries prevalence in children. Caries prevention should already begin during the prenatal period primarily in respect of mothers with lower educational attainment who are pregnant with a second or subsequent child. Copyright © 2015 Elsevier GmbH. All rights reserved.

Three success factors for continual improvement in healthcare: an analysis of the reports of improvement team members.

PubMed

Brandrud, Aleidis Skard; Schreiner, Ada; Hjortdahl, Per; Helljesen, Gro Sævil; Nyen, Bjørnar; Nelson, Eugene C

2011-03-01

The objectives of the Breakthrough Series Collaborative are to close the gap between what we know and what we do, and to contribute to continuous quality improvement (CQI) of healthcare through collaborative learning. The improvement efforts are guided by a systematic approach, combining professional and improvement knowledge. To explore what the improvement teams have learnt from participating in the collaborative and from dealing with promoting and inhibiting factors encountered. Qualitative interviews with 19 team members were conducted in four focus groups, using the Critical Incident Technique. A critical incident is one that makes significant contributions, either positively or negatively, to an activity. The elements of a culture of improvement are revealed by the critical incidents, and reflect the eight domains of knowledge, as a product of collaborative learning. The improvement knowledge and skills of individuals are important elements, but not enough to achieve sustainable changes. 90% of the material reflects the need for a system of CQI to solve the problems that organisations experience in trying to make lasting improvements. A pattern of three success factors for CQI emerges: (1) continuous and reliable information, including measurement, about best and current practice; (2) engagement of everybody in all phases of the improvement work: the patient and family, the leadership, the professional environment and the staff; and (3) an infrastructure based on improvement knowledge, with multidisciplinary teams, available coaching, learning systems and sustainability systems.

The contribution of socioeconomic factors to PM2.5 pollution in urban China.

PubMed

Jiang, Peng; Yang, Jun; Huang, Conghong; Liu, Huakui

2018-02-01

PM 2.5 pollution poses severe health risks to urban residents in low and middle-income countries. Existing studies have shown that the problem is affected by multiple socioeconomic factors. However, the relative contribution of these factors is not well understood, which sometimes leads to controversial controlling measures. In this study, we quantified the relative contribution of different socioeconomic factors, including the city size, industrial activities, and residents' activities, to PM 2.5 pollution in urban China between 2014 and 2015 by using structural equation model (SEM). Our results showed that industrial activities contributed more to PM 2.5 pollution than other factors. The city size and residents' activities also had significant impacts on PM 2.5 pollution. The combined influence of all socioeconomic factors could explain between 44% and 48% of variation in PM 2.5 pollution, which indicated the existence of influences from other factors such as weather conditions and outside sources of pollutants. Findings from our study can contribute to a more comprehensive understanding of the socioeconomic causes of PM 2.5 pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

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

Tikalsky, Paul J.; Bahia, Hussain U.; Deng, An

2004-10-15

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Notmore » limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.« less

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

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

Pauul J. Tikalsky

2004-10-31

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: (1) a statistically sound evaluation of the characterization of foundry sand, (2) a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and (3) the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis andmore » leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at N{sub ini}, N{sub des}, and N{sub max}. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.« less

On the factors influencing the performance of solar reactors for water disinfection with photosensitized singlet oxygen.

PubMed

Manjón, Francisco; Villén, Laura; García-Fresnadillo, David; Orellana, Guillermo

2008-01-01

Two solar reactors based on compound parabolic collectors (CPCs) were optimized for water disinfection by photosensitized singlet oxygen (1O2) production in the heterogeneous phase. Sensitizing materials containing Ru(II) complexes immobilized on porous silicone were produced, photochemically characterized, and successfully tested for the inactivation of up to 10(4) CFU mL(-1) of waterborne Escherichia coli (gram-negative) or Enterococcus faecalis (gram-positive) bacteria. The main factors determining the performance of the solar reactors are the type of photosensitizing material, the sensitizer loading, the CPC collector geometry (fin- vs coaxial-type), the fluid rheology, and the balance between concurrent photothermal--photolytic and 1O2 effects on the microorganisms' inactivation. In this way, at the 40 degrees N latitude of Spain, water can be disinfected on a sunny day (0.6-0.8 MJ m(-2) L(-1) accumulated solar radiation dose in the 360-700 nm range, typically 5-6 h of sunlight) with a fin-type reactor containing 0.6 m2 of photosensitizing material saturated with tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) (ca. 2.0 g m(-2)). The optimum rheological conditions require laminar-to-transitional water flow in both prototypes. The fin-type system showed better inactivation efficiency than the coaxial reactor due to a more important photolytic contribution. The durability of the sensitizing materials was tested and the operational lifetime of the photocatalyst is at least three months without any reduction in the bacteria inactivation efficiency. Solar water disinfection with 1O2-generating films is demonstrated to be an effective technique for use in isolated regions of developing countries with high yearly average sunshine.

Chemical, physical, and environmental properties of pelleted newspaper compared to wheat straw and wood shavings as bedding for horses.

PubMed

Ward, P L; Wohlt, J E; Katz, S E

2001-06-01

Two experiments were conducted comparing pelleted recycled newspaper (PN) to wheat straw (S) and kiln-dried pine wood shavings (WS) as an animal bedding material. Adult horses housed 20 to 21 h/d in boxstalls served as the animal model for comparisons. In Exp. 1 eight boxstalls, each housing one horse, were each bedded with two types of PN (0.32 and 0.64 x 2.54 cm), S, and WS over four 5-d periods (replicated 4 x 4 Latin square). Initial amounts of bedding materials surpassed most commercial conditions, but stalls were cleaned daily of feces only and additional clean bedding was added as needed to maintain animal cleanliness, thus challenging the bedding properties of each material. In Exp. 2 nine boxstalls were bedded with PN (0.32 x 2.54 cm), S, and WS over three 14-d periods (three 3 x 3 Latin squares) during summer and autumn. Feces and wet spots were removed daily and clean bedding was added to reestablish working volume and simulate commercial conditions. In Exp. 1 and 2 daily additions of clean bedding varied (P < 0.05) with material (S > WS > PN). The higher water-holding capacity of PN and WS contributed to fewer bedding replacements. Usage of each material was greater (P < 0.05) during the autumn; PN had the greatest increase. Type of material and season also influenced bedding environment. Bedding pH increased (P < 0.05) with use and was highest in PN and lowest in S. Higher concentrations of breathable NH3 N were present in stalls bedded with PN and during autumn. Higher pH of used PN and decreased ventilation due to closed doors and windows during autumn were contributing factors. Season, type of bedding, and duration of its use affected (P < 0.05) numbers as well as species of microorganisms present in the breathing zone, nasal cavity, and on the leg of the horse. Clean and used WS contained greater (P < 0.05) quantities of particle fines, but with 5 d of use, particle fines in PN also increased. Quantities of breathable dust during cleaning of stalls varied (P < 0.05) with material and duration of its use; dust peaked at d 7 with PN but continued to decrease with S and to increase with WS through d 14. These data indicate that management of bedding materials varies with type of material and season of year. Use of PN as a bedding material has high potential.

All auto shredding: evaluation of automotive shredder residue generated by shredding only vehicles.

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

Duranceau, C. M.; Spangenberger, J. S.; Vehicle Recycling Partnership, LLC)

A well developed infrastructure exists for the reuse and recycling of automotive parts and materials. At the end of a vehicle's useful life many parts are removed and sold for reuse and fluids are recovered for recycling or proper disposal. What remains is shredded, along with other metal bearing scrap such as home appliances, demolition debris and process equipment, and the metals are separated out and recycled. The remainder of the vehicle materials is call shredder residue which ends up in the landfill. As energy and natural resources becomes more treasured, increased effort has been afforded to find ways tomore » reduce energy consumption and minimize the use of our limited resources. Many of the materials found in shredder residue could be recovered and help offset the use of energy and material consumption. For example, the energy content of the plastics and rubbers currently landfilled with the shredder residue is equivalent to 16 million barrels of oil per year. However, in the United States, the recovered materials, primarily polymers, cannot be recycled due to current regulatory barriers which preclude the re-introduction into commerce of certain materials because of residual contamination with substances of concern (SOCs) such as polychlorinated biphenyls (PCBs). The source of the PCBs is not well understood. Old transformers, capacitors, white goods and ballasts from lighting fixtures are likely contributing factors. The project was designed to evaluate whether vehicles of varying age and manufacturing origin contribute to the PCB content in shredder residue. Additionally, the project was designed to determine if there are any trends in material composition of the shredder residue from varied age and manufacturing groups. This information would aid in future material recovery facility strategy and design. The test utilized a newly installed shredder plant to shred four categories of automobiles. The categories were defined by vehicle age and the manufacturing company and location. Each category of vehicles was processed individually through the shredder plant and the resulting shredder residue was analyzed for its materials composition and presence of PCBs and leachable metals. The results show that shredder residue from all vehicle categories tested are not significant contributors of PCBs and leachable metals. It was evident that leachable cadmium levels have decreased in newer vehicles. The composition of the shredder residue from each of the four categories is similar to the others. In addition, these compositions are approximately equal to the composition of typical shredder residues, not limited to automotive materials.« less

Laboratory evaluation of thermal protective clothing performance upon hot liquid splash.

PubMed

Gholamreza, Farzan; Song, Guowen

2013-07-01

This study provides an understanding of heat and mass transfer through materials exposed to hot liquid splash, a relatively unexplored hazard in the safety clothing industry. Selected fabrics and layered systems were exposed to three hot liquids to study the effects of hot liquids and configuration. To explore the energy transfer mechanisms, a modified apparatus (based on ASTM F 2701-08) was developed to assess the protection performance provided by a fabric when exposed to a hot liquid. The modified test method allows measurement of the energy absorbed by the sensor, and with the use of a skin model, the time required to produce a second-degree burn injury was predicted. The preliminary testing demonstrated that mass transfer of the hot liquid through the fabric is the main factor contributing to burn injury. Key factors that determine the level of protection that a fabric system provides are summarized.

Formal appraisal of undergraduate medical students: is it worth the effort?

PubMed

Murdoch-Eaton, Deborah G; Levene, Malcolm I

2004-02-01

Medical student stress is most often related to difficulties of adjusting to university academic standards, and work-social life balance. Faculty systems identify academically failing students for counselling, whilst the majority of students do not have opportunities for individual discussion about progress. This study reports a pilot formal appraisal process for first-year undergraduates. Preparatory material required students to reflect on their academic performance, factors contributing to their university life and satisfaction with career choice. Individual appraisal sessions were held with trained, experienced senior faculty staff, with completion of an appraisal record to document agreed outcomes. Individualized study skills advice was the commonest documented outcome on appraisal records. Students were overwhelmingly positive about the experience, reporting both enhanced perceptions of faculty and reduced anxiety about academic performance. Medical schools have responsibilities to consider ways to optimize students' performance; attainment can be related more to personal and motivational factors than academic ability.

Calculated transport properties of CdO: thermal conductivity and thermoelectric power factor

DOE PAGES

Lindsay, Lucas R.; Parker, David S.

2015-10-01

We present first principles calculations of the thermal and electronic transport properties of the oxide semiconductor CdO. In particular, we find from theory that the accepted thermal conductivity κ value of 0.7 Wm -1K -1 is approximately one order of magnitude too small; our calculations of κ of CdO are in good agreement with recent measurements. We also find that alloying of MgO with CdO is an effective means to reduce the lattice contribution to κ, despite MgO having a much larger thermal conductivity. We further consider the electronic structure of CdO in relation to thermoelectric performance, finding that largemore » thermoelectric power factors may occur if the material can be heavily doped p-type. This work develops insight into the nature of thermal and electronic transport in an important oxide semiconductor.« less

Effects of oxidation and roughness on Cu contact resistance from 4 to 290 K

NASA Technical Reports Server (NTRS)

Nilles, M. J.; Van Sciver, S. W.

1988-01-01

Knowledge of the factors influencing contact resistance is important for optimizing system design in cryogenic applications. In space cryogenics, indirect cooling of infrared components is the primary concern. The presence of bolted joints results in contact resistances which can dominate all other contributions to the overall heat transfer rate. Here, thermal and electrical contact resistances measured between 4 K and 290 K for a series of bolted OFHC Cu contacts are reported. Surface roughness is found to have little effect on the overall contact resistance within the experimental limits, while oxidation can increase the contact resistance by as much as a factor of 100. Thermal and electrical contact resistances measured on the same contact show that the contact resistance temperature dependence does not follow the bulk dependence. For example, the residual resistance ratio (RRR) of the OFHC Cu is 110, but for contacts made from this material, the RRR is about two.

SEM characterization of anatomical variation in chitin organization in insect and arthropod cuticles.

PubMed

Chandran, Rakkiyappan; Williams, Lee; Hung, Albert; Nowlin, Kyle; LaJeunesse, Dennis

2016-03-01

The cuticles of insects and arthropods have some of the most diverse material properties observed in nature, so much so that it is difficult to imagine that all cutciles are primarily composed of the same two materials: a fibrous chitin network and a matrix composed of cuticle proteins. Various factors contribute to the mechanical and optical properties of an insect or arthropod cuticle including the thickness and composition. In this paper, we also identified another factor that may contribute to the optical, surface, and mechanical properties of a cuticle, i.e. the organization of chitin nanofibers and chitin fiber bundles. Self-assembled chitin nanofibers serve as the foundation for all higher order chitin structures in the cuticles of insects and other arthropods via interactions with structural cuticle proteins. Using a technique that enables the characterization of chitin organization in the cuticle of intact insects and arthropod exoskeletons, we demonstrate a structure/function correlation of chitin organization with larger scale anatomical structures. The chitin scaffolds in cuticles display an extraordinarily diverse set of morphologies that may reflect specific mechanical or physical properties. After removal of the proteinaceous and mineral matrix of a cuticle, we observe using SEM diverse nanoscale and micro scale organization of in-situ chitin in the wing, head, eye, leg, and dorsal and ventral thoracic regions of the periodical cicada Magicicada septendecim and in other insects and arthropods. The organization of chitin also appears to have a significant role in the organization of nanoscale surface structures. While microscale bristles and hairs have long been known to be chitin based materials formed as cellular extensions, we have found a nanostructured layer of chitin in the cuticle of the wing of the dog day annual cicada Tibicen tibicens, which may be the scaffold for the nanocone arrays found on the wing. We also use this process to examine the chitin organizations in the fruit fly, Drosophila melanogaster, and the Atlantic brown shrimp, Farfantepenaeus aztecus. Interestingly many of the homologous anatomical structures from diverse arthropods exhibit similar patterns of chitin organization suggesting that a common set of parameters, govern chitin organization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inferring sediment connectivity from high-resolution DEMs of Difference

NASA Astrophysics Data System (ADS)

Heckmann, Tobias; Vericat, Damià

2017-04-01

Topographic changes due to the erosion and deposition of bedrock, sediments and soil can be measured by differencing Digital Elevation Models (DEM) acquired at different points in time. So-called morphological sediment budgets can be computed from such DEMs of Difference (DoD) on an areal rather than a point basis. The advent of high-resolution and highly accurate surveying techniques (e.g. LiDAR, SfM), together with recent advances of survey platforms (e.g. UaVs) provides opportunities to improve the spatial and temporal scale (in terms of extent and resolution), the availability and quality of such measurements. Many studies have used DoD to investigate and interpret the spatial pattern of positive and negative vertical differences in terms of erosion and deposition, or of horizontal movement. Vertical differences can be converted to volumes, and negative (erosion) and positive (deposition) volumetric changes aggregated for spatial units (e.g., landforms, hillslopes, river channels) have been used to compute net balances. We argue that flow routing algorithms common in digital terrain analysis provide a means to enrich DoD-based investigations with some information about (potential) sediment pathways - something that has been widely neglected in previous studies. Where the DoD indicates a positive surface change, flow routing delineates the upslope area where the deposited sediment has potentially been derived from. In the downslope direction, flow routing indicates probable downslope pathways of material eroded/detached/entrained where the DoD shows negative surface change. This material has either been deposited along these pathways or been flushed out of the area of investigation. This is a question of sediment connectivity, a property of a system (i.e. a hillslope, a sub-/catchment) that describes its potential to move sediment through itself. The sediment pathways derived from the DEM are related to structural connectivity, while the spatial pattern of (net) erosion and deposition has emerged from sediment transfer between the two epochs of the DoD (i.e. functional connectivity). In this study, we use multitemporal raster DEMs generated (i) from terrestrial LiDAR surveys and (ii) by a landscape evolution model to compute DoDs. Flow accumulation is used to compute, for the contributing area of each raster cell, (i) the net balance and (ii) the total sum of material eroded. The net balance represents the sediment yield of the contributing area. In the case of a study area delimited by a catchment boundary, it is either negative (more sediment eroded than deposited within the contributing area, i.e. net export) or zero (eroded material has been re-deposited within the contributing area). Finally, the ratio of sediment yield and gross erosion is called the sediment delivery ratio (SDR). This number has been used as a "performance factor" indicating the degree of sediment connectivity, as it describes the proportion of material eroded on the local scale that is being delivered to the outlet of the contributing area. The evaluation of a DoD to compute the SDR overcomes one major criticism of the SDR, namely that gross erosion is generally estimated (e.g. by empirical USLE-type equations) rather than measured. Both our proposed approach and the concept of SDR are subject to a number of caveats, which we will discuss in our contribution. In any case, we advocate more detailed analyses of DoD using flow routing algorithms in order to include information on potential sediment pathways in morphological sediment budgets for hillslopes and catchments.

Parametric design of pressure-relieving foot orthosis using statistics-based finite element method.

PubMed

Cheung, Jason Tak-Man; Zhang, Ming

2008-04-01

Custom-molded foot orthoses are frequently prescribed in routine clinical practice to prevent or treat plantar ulcers in diabetes by reducing the peak plantar pressure. However, the design and fabrication of foot orthosis vary among clinical practitioners and manufacturers. Moreover, little information about the parametric effect of different combinations of design factors is available. As an alternative to the experimental approach, therefore, computational models of the foot and footwear can provide efficient evaluations of different combinations of structural and material design factors on plantar pressure distribution. In this study, a combined finite element and Taguchi method was used to identify the sensitivity of five design factors (arch type, insole and midsole thickness, insole and midsole stiffness) of foot orthosis on peak plantar pressure relief. From the FE predictions, the custom-molded shape was found to be the most important design factor in reducing peak plantar pressure. Besides the use of an arch-conforming foot orthosis, the insole stiffness was found to be the second most important factor for peak pressure reduction. Other design factors, such as insole thickness, midsole stiffness and midsole thickness, contributed to less important roles in peak pressure reduction in the given order. The statistics-based FE method was found to be an effective approach in evaluating and optimizing the design of foot orthosis.

Risk Factors Influencing Smoking Behavior: A Turkish Twin Study

PubMed Central

Öncel, Sevgi Yurt; Dick, Danielle M.; Maes, Hermine H.; Alıev, Fazil

2015-01-01

Aim In this study, we introduce the first twin study in Turkey, focusing on smoking behavior, and laying the foundation to register all twins born in Turkey for research purposes. Using Turkish twins will contribute to our understanding of health problems in the context of cultural differences. Materials and methods We assessed 309 twin pairs (339 males and 279 females) aged between 15 and 45 years living in the Kırıkkale and Ankara regions of Turkey, and administered a health and lifestyle interview that included questions about smoking status and smoking history. We analyzed the data using descriptive statistics, t-tests, chi-square tests, and bivariate and multivariate clustered logistic regression. In addition, we fit bivariate Structural Equation Models (SEM) to determine contributions of latent genetic and environmental factors to smoking outcomes in this sample. Results One hundred seventy-eight participants (28.8%) were identified as smokers, smoking every day for a month or longer, of whom 79.2% were males and 20.8% were females. Mean values for number of cigarettes per day and the Fagerstrom Test of Nicotine Dependence (FTND; Fagerstrom, 1978) score were higher in males than in females, and age of onset was earlier in males. There was a significant positive correlation between the FTND score and number of cigarettes smoked per day, and a significant negative correlation between both variables and age at onset of smoking. Our study showed that gender, presence of a smoking twin in the family, age, alcohol use, marital status, daily sports activities, and feeling moody all played a significant role in smoking behavior among twins. The twin analysis suggested that 79.5% of the liability to FTND was influenced by genetic factors and 20.5% by unique environment, while familial resemblance for smoking initiation was best explained by common environmental factors. Conclusions Marked differences in the prevalence of smoking behavior in men versus women were observed for the Turkish population. Genetic analyses showed that common environmental factors primarily contributed to smoking initiation, while genetic factors explained a greater proportion of variance in liability to nicotine dependence. Our study shows higher heritability estimate of the FTND scores and higher shared environmental influence on smoking initiation for both males and females than reported in previous studies. PMID:25431287

Can better infrastructure and quality reduce hospital infant mortality rates in Mexico?

PubMed

Aguilera, Nelly; Marrufo, Grecia M

2007-02-01

Preliminary evidence from hospital discharges hints enormous disparities in infant hospital mortality rates. At the same time, public health agencies acknowledge severe deficiencies and variations in the quality of medical services across public hospitals. Despite these concerns, there is limited evidence of the contribution of hospital infrastructure and quality in explaining variations in outcomes among those who have access to medical services provided at public hospitals. This paper provides evidence to address this question. We use probabilistic econometric methods to estimate the impact of material and human resources and hospital quality on the probability that an infant dies controlling for socioeconomic, maternal and reproductive risk factors. As a measure of quality, we calculate for the first time for Mexico patient safety indicators developed by the AHRQ. We find that the probability to die is affected by hospital infrastructure and by quality. In this last regard, having been treated in a hospital with the worse quality incidence doubles the probability to die. This paper also presents evidence on the contribution of other risk factors on perinatal mortality rates. The conclusions of this paper suggest that lower infant mortality rates can be reached by implementing a set of coherent public policy actions including an increase and reorganization of hospital infrastructure, quality improvement, and increasing demand for health by poor families.

Phages and the Evolution of Bacterial Pathogens: from Genomic Rearrangements to Lysogenic Conversion

PubMed Central

Brüssow, Harald; Canchaya, Carlos; Hardt, Wolf-Dietrich

2004-01-01

Comparative genomics demonstrated that the chromosomes from bacteria and their viruses (bacteriophages) are coevolving. This process is most evident for bacterial pathogens where the majority contain prophages or phage remnants integrated into the bacterial DNA. Many prophages from bacterial pathogens encode virulence factors. Two situations can be distinguished: Vibrio cholerae, Shiga toxin-producing Escherichia coli, Corynebacterium diphtheriae, and Clostridium botulinum depend on a specific prophage-encoded toxin for causing a specific disease, whereas Staphylococcus aureus, Streptococcus pyogenes, and Salmonella enterica serovar Typhimurium harbor a multitude of prophages and each phage-encoded virulence or fitness factor makes an incremental contribution to the fitness of the lysogen. These prophages behave like “swarms” of related prophages. Prophage diversification seems to be fueled by the frequent transfer of phage material by recombination with superinfecting phages, resident prophages, or occasional acquisition of other mobile DNA elements or bacterial chromosomal genes. Prophages also contribute to the diversification of the bacterial genome architecture. In many cases, they actually represent a large fraction of the strain-specific DNA sequences. In addition, they can serve as anchoring points for genome inversions. The current review presents the available genomics and biological data on prophages from bacterial pathogens in an evolutionary framework. PMID:15353570

On the influence of manufacturing practices on the SCC behavior of Alloy 690 steam generator tubing

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

Doherty, P.E.; Doyle, D.M.; Sarver, J.M.

1996-12-31

Thermally treated (TT) Alloy 690 is the tubing materials of choice for replacement steam generators (RSGs) throughout the world. It is manufactured using a variety of processing methods with regards to melt practice and thermomechanical forming. Studies assessing the IGSCC resistance of Alloy 690 TT SG tubing have identified a variability in the corrosion performance of nominally identical alloys. While tubing of comparable bulk chemistry may exhibit variations in microchemistry as a result of different melt practice, the correlation between melt practice and SCC resistance is difficult to assess due to other contributing factors. The other contributing factors are identifiedmore » in this investigation as microstructural features whose generation is dependent on features of particular strain-anneal forming methods by which SG tubes are fabricated. In this study the microstructural characteristics which appear to affect inservice corrosion performance of Alloy 690 TT SG tubes were evaluated. The studies included extensive microstructural examinations in addition to CERT tests performed on actual Alloy 690 TT nuclear SG tubing. The CERT test results indicate that Alloy 690 TT tubing processed at higher mill anneal temperatures display the highest degree of stress corrosion cracking (SCC) resistance. This observation is discussed with reference to carbide distributions, textural aspects and grain boundary orientation character.« less

Defects, Entropy, and the Stabilization of Alternative Phase Boundary Orientations in Battery Electrode Particles

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

Heo, Tae Wook; Tang, Ming; Chen, Long-Qing

Using a novel statistical approach that efficiently explores the space of possible defect configurations, our present study investigates the chemomechanical coupling between interfacial structural defects and phase boundary alignments within phase-separating electrode particles. Applied to the battery cathode material Li XFePO 4 as an example, the theoretical analysis reveals that small, defect-induced deviations from an ideal interface can lead to dramatic shifts in the orientations of phase boundaries between Li-rich and Li-lean phases, stabilizing otherwise unfavorable orientations. Significantly, this stabilization arises predominantly from configurational entropic factors associated with the presence of the interfacial defects rather than from absolute energetic considerations.more » The specific entropic factors pertain to the diversity of defect configurations and their contributions to rotational/orientational rigidity of phase boundaries. Comparison of the predictions with experimental observations indicates that the additional entropy contributions indeed play a dominant role under actual cycling conditions, leading to the conclusion that interfacial defects must be considered when analyzing the stability and evolution kinetics of the internal phase microstructure of strongly phase-separating systems. Possible implications for tuning the kinetics of (de)lithiation based on selective defect incorporation are discussed. Ultimately, this understanding can be generalized to the chemomechanics of other defective solid phase boundaries.« less

Defects, Entropy, and the Stabilization of Alternative Phase Boundary Orientations in Battery Electrode Particles

DOE PAGES

Heo, Tae Wook; Tang, Ming; Chen, Long-Qing; ...

2016-01-04

Using a novel statistical approach that efficiently explores the space of possible defect configurations, our present study investigates the chemomechanical coupling between interfacial structural defects and phase boundary alignments within phase-separating electrode particles. Applied to the battery cathode material Li XFePO 4 as an example, the theoretical analysis reveals that small, defect-induced deviations from an ideal interface can lead to dramatic shifts in the orientations of phase boundaries between Li-rich and Li-lean phases, stabilizing otherwise unfavorable orientations. Significantly, this stabilization arises predominantly from configurational entropic factors associated with the presence of the interfacial defects rather than from absolute energetic considerations.more » The specific entropic factors pertain to the diversity of defect configurations and their contributions to rotational/orientational rigidity of phase boundaries. Comparison of the predictions with experimental observations indicates that the additional entropy contributions indeed play a dominant role under actual cycling conditions, leading to the conclusion that interfacial defects must be considered when analyzing the stability and evolution kinetics of the internal phase microstructure of strongly phase-separating systems. Possible implications for tuning the kinetics of (de)lithiation based on selective defect incorporation are discussed. Ultimately, this understanding can be generalized to the chemomechanics of other defective solid phase boundaries.« less

The contribution of human agricultural activities to increasing evapotranspiration is significantly greater than climate change effect over Heihe agricultural region.

PubMed

Zou, Minzhong; Niu, Jun; Kang, Shaozhong; Li, Xiaolin; Lu, Hongna

2017-08-18

Evapotranspiration (ET) is a major component linking the water, energy, and carbon cycles. Understanding changes in ET and the relative contribution rates of human activity and of climate change at the basin scale is important for sound water resources management. In this study, changes in ET in the Heihe agricultural region in northwest China during 1984-2014 were examined using remotely-sensed ET data with the Soil and Water Assessment Tool (SWAT). Correlation analysis identified the dominant factors that influence change in ET per unit area and those that influence change in total ET. Factor analysis identified the relative contribution rates of the dominant factors in each case. The results show that human activity, which includes factors for agronomy and irrigation, and climate change, including factors for precipitation and relative humidity, both contribute to increases in ET per unit area at rates of 60.93% and 28.01%, respectively. Human activity, including the same factors, and climate change, including factors for relative humidity and wind speed, contribute to increases in total ET at rates of 53.86% and 35.68%, respectively. Overall, in the Heihe agricultural region, the contribution of human agricultural activities to increased ET was significantly greater than that of climate change.

Personality Factors in Elementary School Children: Contributions to Academic Performance over and above Executive Functions?

ERIC Educational Resources Information Center

Neuenschwander, Regula; Cimeli, Patrizia; Rothlisberger, Marianne; Roebers, Claudia M.

2013-01-01

Unique contributions of Big Five personality factors to academic performance in young elementary school children were explored. Extraversion and Openness (labeled "Culture" in our study) uniquely contributed to academic performance, over and above the contribution of executive functions in first and second grade children (N = 446). Well…

Properties of Residue from Olive Oil Extraction as a Raw Material for Sustainable Construction Materials. Part I: Physical Properties

PubMed Central

Díaz-García, Almudena; Martínez-García, Carmen; Cotes-Palomino, Teresa

2017-01-01

Action on climate, the environment, and the efficient use of raw materials and resources are important challenges facing our society. Against this backdrop, the construction industry must adapt to new trends and environmentally sustainable construction systems, thus requiring lines of research aimed at keeping energy consumption in new buildings as low as possible. One of the main goals of this research is to efficiently contribute to reducing the amount of residue from olive oil extraction using a two-phase method. This can be achieved by producing alternative structural materials to be used in the construction industry by means of a circular economy. The technical feasibility of adding said residue to ceramic paste was proven by analyzing the changes produced in the physical properties of the paste, which were then compared to the properties of the reference materials manufactured with clay without residue. Results obtained show that the heating value of wet pomace can contribute to the thermal needs of the sintering process, contributing 30% of energy in pieces containing 3% of said material. Likewise, adding larger amounts of wet pomace to the clay body causes a significant decrease in bulk density values. PMID:28772461

Korean Early Childhood Educators' Multi-Dimensional Teacher Self-Efficacy and ECE Center Climate and Depression Severity in Teachers as Contributing Factors

ERIC Educational Resources Information Center

Kim, Yeon Ha; Kim, Yang Eun

2010-01-01

This study investigated profiles of South Korean early childhood educators' teacher self-efficacy and contributing factors to teacher self-efficacy. The contributing factors were examined with a focus on early childhood education (ECE) center climate and depression severity in teachers as well as teacher and classroom characteristics. The results…

Advanced ceramic materials for next-generation nuclear applications

NASA Astrophysics Data System (ADS)

Marra, John

2011-10-01

The nuclear industry is at the eye of a 'perfect storm' with fuel oil and natural gas prices near record highs, worldwide energy demands increasing at an alarming rate, and increased concerns about greenhouse gas (GHG) emissions that have caused many to look negatively at long-term use of fossil fuels. This convergence of factors has led to a growing interest in revitalization of the nuclear power industry within the United States and across the globe. Many are surprised to learn that nuclear power provides approximately 20% of the electrical power in the US and approximately 16% of the world-wide electric power. With the above factors in mind, world-wide over 130 new reactor projects are being considered with approximately 25 new permit applications in the US. Materials have long played a very important role in the nuclear industry with applications throughout the entire fuel cycle; from fuel fabrication to waste stabilization. As the international community begins to look at advanced reactor systems and fuel cycles that minimize waste and increase proliferation resistance, materials will play an even larger role. Many of the advanced reactor concepts being evaluated operate at high-temperature requiring the use of durable, heat-resistant materials. Advanced metallic and ceramic fuels are being investigated for a variety of Generation IV reactor concepts. These include the traditional TRISO-coated particles, advanced alloy fuels for 'deep-burn' applications, as well as advanced inert-matrix fuels. In order to minimize wastes and legacy materials, a number of fuel reprocessing operations are being investigated. Advanced materials continue to provide a vital contribution in 'closing the fuel cycle' by stabilization of associated low-level and high-level wastes in highly durable cements, ceramics, and glasses. Beyond this fission energy application, fusion energy will demand advanced materials capable of withstanding the extreme environments of high-temperature plasma systems. Fusion reactors will likely depend on lithium-based ceramics to produce tritium that fuels the fusion plasma, while high-temperature alloys or ceramics will contain and control the hot plasma. All the while, alloys, ceramics, and ceramic-related processes continue to find applications in the management of wastes and byproducts produced by these processes.

Mechanism for Angular Deformation of L-shaped Specimens —Influence of Filling Material and Shrinkage Factor—

NASA Astrophysics Data System (ADS)

Furuhashi, Hiroshi; Aoki, Takerou; Okabe, Sayaka; Arai, Tsuyoshi; Seto, Masahiro; Yamabe, Masashi

L-shape is the important and fundamental shape for injection molded parts. Therefore to reveal the corner angular deformation mechanism of this shape is also valuable for understanding the warpage mechanism of injection molded parts. In this study, we investigated the influence of the filling materials (fiber, talc and not filled) and two kinds of anisotropic shrinkage factors, solidification shrinkage and shrinkage caused by thermal expansion coefficient during cooling, to the angular deformation of L-shaped specimens and the following conclusions were obtained 1) The anisotropic solidification shrinkage of MD/TD and the anisotropic thermal expansion coefficient of MD/TD are considered to cause the angular deformation of L-shaped specimens. But the contribution ratios of these two anisotropies depend on the filling material for plastics. 2) The angular deformation of PP and PBT filled with glass fiber is mainly caused by the anisotropic thermal expansion coefficient and on the other hand, that of PP and PBT without filling material is caused by anisotropic solidification shrinkage. However both anisotropies cause the angular deformation of PP filled with talc. 3) The plate thickness dependence of the angular deformation of PP filled with talc is the singular peculiar phenomenon. The plate thickness dependence of anisotropic solidification shrinkage of this material (it is also singular) is considered to have an important influence on this phenomenon.

Analytical methods for the measurement of polymerization kinetics and stresses of dental resin-based composites: A review

PubMed Central

Ghavami-Lahiji, Mehrsima; Hooshmand, Tabassom

2017-01-01

Resin-based composites are commonly used restorative materials in dentistry. Such tooth-colored restorations can adhere to the dental tissues. One drawback is that the polymerization shrinkage and induced stresses during the curing procedure is an inherent property of resin composite materials that might impair their performance. This review focuses on the significant developments of laboratory tools in the measurement of polymerization shrinkage and stresses of dental resin-based materials during polymerization. An electronic search of publications from January 1977 to July 2016 was made using ScienceDirect, PubMed, Medline, and Google Scholar databases. The search included only English-language articles. Only studies that performed laboratory methods to evaluate the amount of the polymerization shrinkage and/or stresses of dental resin-based materials during polymerization were selected. The results indicated that various techniques have been introduced with different mechanical/physical bases. Besides, there are factors that may contribute the differences between the various methods in measuring the amount of shrinkages and stresses of resin composites. The search for an ideal and standard apparatus for measuring shrinkage stress and volumetric polymerization shrinkage of resin-based materials in dentistry is still required. Researchers and clinicians must be aware of differences between analytical methods to make proper interpretation and indications of each technique relevant to a clinical situation. PMID:28928776

Temporal properties of material categorization and material rating: visual vs non-visual material features.

PubMed

Nagai, Takehiro; Matsushima, Toshiki; Koida, Kowa; Tani, Yusuke; Kitazaki, Michiteru; Nakauchi, Shigeki

2015-10-01

Humans can visually recognize material categories of objects, such as glass, stone, and plastic, easily. However, little is known about the kinds of surface quality features that contribute to such material class recognition. In this paper, we examine the relationship between perceptual surface features and material category discrimination performance for pictures of materials, focusing on temporal aspects, including reaction time and effects of stimulus duration. The stimuli were pictures of objects with an identical shape but made of different materials that could be categorized into seven classes (glass, plastic, metal, stone, wood, leather, and fabric). In a pre-experiment, observers rated the pictures on nine surface features, including visual (e.g., glossiness and transparency) and non-visual features (e.g., heaviness and warmness), on a 7-point scale. In the main experiments, observers judged whether two simultaneously presented pictures were classified as the same or different material category. Reaction times and effects of stimulus duration were measured. The results showed that visual feature ratings were correlated with material discrimination performance for short reaction times or short stimulus durations, while non-visual feature ratings were correlated only with performance for long reaction times or long stimulus durations. These results suggest that the mechanisms underlying visual and non-visual feature processing may differ in terms of processing time, although the cause is unclear. Visual surface features may mainly contribute to material recognition in daily life, while non-visual features may contribute only weakly, if at all. Copyright © 2014 Elsevier Ltd. All rights reserved.

On the conservation of easel paintings: evaluation of microbial contamination and artists materials

NASA Astrophysics Data System (ADS)

Salvador, Cátia; Bordalo, Rui; Silva, Mara; Rosado, Tânia; Candeias, António; Caldeira, Ana Teresa

2017-01-01

Easel paintings have been considered one of the most important art expressions, constituting today outstanding works of art with important historic and cultural value. Unfortunately, due to the presence of several organic materials, these artworks have been affected by microbial contamination that among other factors can be responsible for different aesthetic and structural alterations. For this study, four easel paintings from the late nineteenth century by Giorgio Marini with evident chromatic and structural alterations due to biocontamination were analysed in order to better understand the materials used and the source of high microbial contamination within a focused conservation intervention process. For this end, both the biofilms and the painting materials were characterised by several analytical techniques. Fungal communities were found to prevail in areas with evident structural and aesthetic damages, which were confirmed by scanning electron microscopy analyses that allowed the observation of the fungal hyphae proliferation capacity. Energy-dispersive X-ray spectroscopy, μ-X-ray diffraction, μ-Raman, μ-FTIR and optical microscopy were used to further identify the painting materials. Immunological assays revealed the presence of a mixture of proteins of ovalbumin, collagen and casein, suggesting that the presence of these proteinaceous materials in these paintings is one of the main reasons of microbial biofilms appearance on the painting's surface. These approaches contribute for a better knowledge of these artworks providing at the same time relevant information for the ongoing conservation-restoration intervention.

Insight into interfacial effect on effective physical properties of fibrous materials. I. The volume fraction of soft interfaces around anisotropic fibers.

PubMed

Xu, Wenxiang; Wang, Han; Niu, Yanze; Bai, Jingtao

2016-01-07

With advances in interfacial properties characterization technologies, the interfacial volume fraction is a feasible parameter for evaluating effective physical properties of materials. However, there is a need to determine the interfacial volume fraction around anisotropic fibers and a need to assess the influence of such the interfacial property on effective properties of fibrous materials. Either ways, the accurate prediction of interfacial volume fraction is required. Towards this end, we put forward both theoretical and numerical schemes to determine the interfacial volume fraction in fibrous materials, which are considered as a three-phase composite structure consisting of matrix, anisotropic hard spherocylinder fibers, and soft interfacial layers with a constant dimension coated on the surface of each fiber. The interfacial volume fraction actually represents the fraction of space not occupied by all hard fibers and matrix. The theoretical scheme that adopts statistical geometry and stereological theories is essentially an analytic continuation from spherical inclusions. By simulating such three-phase chopped fibrous materials, we numerically derive the interfacial volume fraction. The theoretical and numerical schemes provide a quantitative insight that the interfacial volume fraction depends strongly on the fiber geometries like fiber shape, geometric size factor, and fiber size distribution. As a critical interfacial property, the present contribution can be further drawn into assessing effective physical properties of fibrous materials, which will be demonstrated in another paper (Part II) of this series.

A study on the cytotoxicity of carbon-based materials

DOE PAGES

Saha, Dipendu; Heldt, Caryn L.; Gencoglu, Maria F.; ...

2016-05-25

With an aim to understand the origin and key contributing factors towards carboninduced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, x-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROX) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicitymore » in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under study. None of the carbons induced oxidative stress to the cells as indicated by the ROX generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell.« less

Impact of stent strut design in metallic stents and biodegradable scaffolds.

PubMed

Foin, Nicolas; Lee, Renick D; Torii, Ryo; Guitierrez-Chico, Juan Luis; Mattesini, Alessio; Nijjer, Sukhjinder; Sen, Sayan; Petraco, Ricardo; Davies, Justin E; Di Mario, Carlo; Joner, Michael; Virmani, Renu; Wong, Philip

2014-12-20

Advances in the understanding of healing mechanisms after stent implantation have led to the recognition of stent strut thickness as an essential factor affecting re-endothelialization and overall long term vessel healing response after Percutaneous Coronary Interventions (PCI). Emergence of Drug-eluting stents (DESs) with anti-proliferative coating has contributed to reducing the incidence of restenosis and Target Lesion Revascularization (TVR), while progress and innovations in stent materials have in the meantime facilitated the design of newer platforms with more conformability and thinner struts, producing lesser injury and improving integration into the vessel wall. Recent advances in biodegradable metal and polymer materials now also allow for the design of fully biodegradable platforms, which are aimed at scaffolding the vessel only temporarily to prevent recoil and constrictive remodeling of the vessel during the initial period required, and are then progressively resorbed thereby avoiding the drawback of leaving an unnecessary implant permanently in the vessel. The aim of this article is to review recent evolution in stent material and stent strut design while understanding their impact on PCI outcomes. The article describes the different metallic alloys and biodegradable material properties and how these have impacted the evolution of stent strut thickness and ultimately outcomes in patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Thermal properties variations in unconsolidated material for very shallow geothermal application (ITER project)

NASA Astrophysics Data System (ADS)

Sipio, Eloisa Di; Bertermann, David

2018-04-01

In engineering, agricultural and meteorological project design, sediment thermal properties are highly important parameters, and thermal conductivity plays a fundamental role when dimensioning ground heat exchangers, especially in very shallow geothermal systems. Herein, the first 2 m of depth from surface is of critical importance. However, the heat transfer determination in unconsolidated material is difficult to estimate, as it depends on several factors, including particle size, bulk density, water content, mineralogy composition and ground temperature. The performance of a very shallow geothermal system, as a horizontal collector or heat basket, is strongly correlated to the type of sediment at disposal and rapidly decreases in the case of dry-unsaturated conditions. The available experimental data are often scattered, incomplete and do not fully support thermo-active ground structure modeling. The ITER project, funded by the European Union, contributes to a better knowledge of the relationship between thermal conductivity and water content, required for understanding the very shallow geothermal systems behaviour in saturated and unsaturated conditions. So as to enhance the performance of horizontal geothermal heat exchangers, thermally enhanced backfilling material were tested in the laboratory, and an overview of physical-thermal properties variations under several moisture and load conditions for different mixtures of natural material was here presented.

Mechanical properties of nanostructure of biological materials

NASA Astrophysics Data System (ADS)

Ji, Baohua; Gao, Huajian

2004-09-01

Natural biological materials such as bone, teeth and nacre are nanocomposites of protein and mineral with superior strength. It is quite a marvel that nature produces hard and tough materials out of protein as soft as human skin and mineral as brittle as classroom chalk. What are the secrets of nature? Can we learn from this to produce bio-inspired materials in the laboratory? These questions have motivated us to investigate the mechanics of protein-mineral nanocomposite structure. Large aspect ratios and a staggered alignment of mineral platelets are found to be the key factors contributing to the large stiffness of biomaterials. A tension-shear chain (TSC) model of biological nanostructure reveals that the strength of biomaterials hinges upon optimizing the tensile strength of the mineral crystals. As the size of the mineral crystals is reduced to nanoscale, they become insensitive to flaws with strength approaching the theoretical strength of atomic bonds. The optimized tensile strength of mineral crystals thus allows a large amount of fracture energy to be dissipated in protein via shear deformation and consequently enhances the fracture toughness of biocomposites. We derive viscoelastic properties of the protein-mineral nanostructure and show that the toughness of biocomposite can be further enhanced by the viscoelastic properties of protein.

Family Material Hardship and Chinese Adolescents’ Problem Behaviors: A Moderated Mediation Analysis

PubMed Central

Sun, Wenqiang; Li, Dongping; Zhang, Wei; Bao, Zhenzhou; Wang, Yanhui

2015-01-01

In the current study, we examined a moderated mediation model using the risk and resilience framework. Specifically, the impact of family material hardship on adolescent problem behaviors was examined in a Chinese sample; we used the family stress model framework to investigate parental depression and negative parenting as potential mediators of the relation between family material hardship and adolescents’ problem behaviors. In addition, based on resilience theory, we investigated adolescents’ resilience as a potential protective factor in the development of their internalizing and externalizing problems. Participants included 1,419 Chinese adolescents (mean age = 15.38 years, SD = 1.79) and their primary caregivers. After controlling for covariates (age, gender, location of family residence, and primary caregiver), we found that parental depression and negative parenting mediated the association between family material hardship and adolescents’ problem behaviors. Furthermore, the adolescent resilience moderated the relationship between negative parenting and internalizing problems in a protective-stabilizing pattern; in addition, a protective-reactive pattern also emerged when adolescent resilience was examined as a moderator of the relationship between negative parenting and externalizing problems. These findings contribute to a comprehensive understanding of the mechanisms of risk and resilience in youth development. Moreover, the findings have important implications for the prevention of adolescent problem behaviors. PMID:26010256

The effect of external mean flow on sound transmission through double-walled cylindrical shells lined with poroelastic material

NASA Astrophysics Data System (ADS)

Zhou, Jie; Bhaskar, Atul; Zhang, Xin

2014-03-01

Sound transmission through a system of double shells, lined with poroelastic material in the presence of external mean flow, is studied. The porous material is modeled as an equivalent fluid because shear wave contributions are known to be insignificant. This is achieved by accounting for the energetically most dominant wave types in the calculations. The transmission characteristics of the sandwich construction are presented for different incidence angles and Mach numbers over a wide frequency range. It is noted that the transmission loss exhibits three dips on the frequency axis as opposed to flat panels where there are only two such frequencies—results are discussed in the light of these observations. Flow is shown to decrease the transmission loss below the ring frequency, but increase this above the ring frequency due to the negative stiffness and the damping effect added by the flow. In the absence of external mean flow, porous material provides superior insulation for most part of the frequency band of interest. However, in the presence of external flow, this is true only below the ring frequency—above this frequency, the presence of air gap in sandwich constructions is the dominant factor that determines the acoustic performance. In the absence of external flow, an air gap always improves sound insulation.

Effective spring stiffness for a periodic array of interacting coplanar penny-shaped cracks at an interface between two dissimilar isotropic materials

PubMed Central

Lekesiz, Huseyin; Katsube, Noriko; Rokhlin, Stanislav I.; Seghi, Robert R.

2013-01-01

An effective spring stiffness approximation is proposed for a hexagonal array of coplanar penny shaped cracks located at the interface between two dissimilar solids. The approximation is based on the factorization of the solution on the material dissimilarity factor, the crack interaction factor and the effective spring stiffness solution for non-interacting cracks in a homogeneous material. Such factorization is exact and was validated for 2D collinear cracks between two dissimilar solids. The crack interaction factor is obtained using a recently developed model for stress intensity factors for an array of coplanar penny shaped cracks in a homogeneous material; also the material dissimilarity function recently obtained for non-interacting penny shaped crack at the interface between two dissimilar materials is employed. The obtained solution is useful for an assessment by ultrasonic measurements of the interface stiffness in bonded structures for monitoring the interfacial microdamage growth due to mechanical loading and environmental factors. PMID:27175036

Effective spring stiffness for a periodic array of interacting coplanar penny-shaped cracks at an interface between two dissimilar isotropic materials.

PubMed

Lekesiz, Huseyin; Katsube, Noriko; Rokhlin, Stanislav I; Seghi, Robert R

2013-08-15

An effective spring stiffness approximation is proposed for a hexagonal array of coplanar penny shaped cracks located at the interface between two dissimilar solids. The approximation is based on the factorization of the solution on the material dissimilarity factor, the crack interaction factor and the effective spring stiffness solution for non-interacting cracks in a homogeneous material. Such factorization is exact and was validated for 2D collinear cracks between two dissimilar solids. The crack interaction factor is obtained using a recently developed model for stress intensity factors for an array of coplanar penny shaped cracks in a homogeneous material; also the material dissimilarity function recently obtained for non-interacting penny shaped crack at the interface between two dissimilar materials is employed. The obtained solution is useful for an assessment by ultrasonic measurements of the interface stiffness in bonded structures for monitoring the interfacial microdamage growth due to mechanical loading and environmental factors.

Agave Chewing and Dental Wear: Evidence from Quids

PubMed Central

Hammerl, Emily E.; Baier, Melissa A.; Reinhard, Karl J.

2015-01-01

Agave quid chewing is examined as a potential contributing behavior to hunter-gatherer dental wear. It has previously been hypothesized that the contribution of Agave quid chewing to dental wear would be observed in communities wherever phytolith-rich desert succulents were part of subsistence. Previous analysis of coprolites from a prehistoric agricultural site, La Cueva de los Muertos Chiquitos in Durango, Mexico, showed that Agave was a consistent part of a diverse diet. Therefore, quids recovered at this site ought to be useful materials to test the hypothesis that dental wear was related to desert succulent consumption. The quids recovered from the site were found to be largely derived from chewing Agave. In this study, the quids were found to be especially rich in phytoliths, and analysis of dental casts made from impressions left in the quids revealed flat wear and dental attrition similar to that of Agave-reliant hunter-gatherers. Based on evidence obtained from the analysis of quids, taken in combination with results from previous studies, it is determined that Agave quid chewing was a likely contributing factor to dental wear in this population. As such, our method provides an additional avenue of dental research in areas where quids are present. PMID:26230855

Critical Concentration Ratio for Solar Thermoelectric Generators

NASA Astrophysics Data System (ADS)

ur Rehman, Naveed; Siddiqui, Mubashir Ali

2016-10-01

A correlation for determining the critical concentration ratio (CCR) of solar concentrated thermoelectric generators (SCTEGs) has been established, and the significance of the contributing parameters is discussed in detail. For any SCTEG, higher concentration ratio leads to higher temperatures at the hot side of modules. However, the maximum value of this temperature for safe operation is limited by the material properties of the modules and should be considered as an important design constraint. Taking into account this limitation, the CCR can be defined as the maximum concentration ratio usable for a particular SCTEG. The established correlation is based on factors associated with the material and geometric properties of modules, thermal characteristics of the receiver, installation site attributes, and thermal and electrical operating conditions. To reduce the number of terms in the correlation, these factors are combined to form dimensionless groups by applying the Buckingham Pi theorem. A correlation model containing these groups is proposed and fit to a dataset obtained by simulating a thermodynamic (physical) model over sampled values acquired by applying the Latin hypercube sampling (LHS) technique over a realistic distribution of factors. The coefficient of determination and relative error are found to be 97% and ±20%, respectively. The correlation is validated by comparing the predicted results with literature values. In addition, the significance and effects of the Pi groups on the CCR are evaluated and thoroughly discussed. This study will lead to a wide range of opportunities regarding design and optimization of SCTEGs.

Next Generation Anodes for Lithium Ion Batteries: Thermodynamic Understanding and Abuse Performance.

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

Fenton, Kyle R.; Allcorn, Eric; Nagasubramanian, Ganesan

The objectives of this project are to elucidate degradation mechanisms, decomposition products, and abuse response for next generation silicon based anodes; and understand the contribution of various materials properties and cell build parameters towards thermal runaway enthalpies. Quantify the contributions from various cell parameters such as particle size, composition, state of charge (SOC), electrolyte to active materials ratio, etc.

The structural science of functional materials.

PubMed

Catlow, C Richard A

2018-01-01

The growing complexity of functional materials and the major challenges this poses to structural science are discussed. The diversity of structural materials science and the contributions that computation is making to the field are highlighted.

Recycling of paper: accounting of greenhouse gases and global warming contributions.

PubMed

Merrild, Hanna; Damgaard, Anders; Christensen, Thomas H

2009-11-01

Greenhouse gas (GHG) emissions have been established for recycling of paper waste with focus on a material recovery facility (MRF). The MRF upgrades the paper and cardboard waste before it is delivered to other industries where new paper or board products are produced. The accounting showed that the GHG contributions from the upstream activities and operational activities, with global warming factors (GWFs) of respectively 1 to 29 and 3 to 9 kg CO(2)-eq. tonne(- 1) paper waste, were small in comparison wih the downstream activities. The GHG contributions from the downstream reprocessing of the paper waste ranged from approximately 490 to 1460 kg CO(2)-eq. tonne( -1) of paper waste. The system may be expanded to include crediting of avoided virgin paper production which would result in GHG contributions from -1270 to 390 kg CO(2)-eq. tonne(- 1) paper waste. It may also be assumed that the wood not used for virgin paper production instead is used for production of energy that in turn is assumed to substitute for fossil fuel energy. This would result in GHG contributions from -1850 to -4400 kg CO(2)-eq. tonne(- 1) of paper waste. These system expansions reveal very large GHG savings, suggesting that the indirect upstream and operational GHG contributions are negligible in comparison with the indirect downstream emissions. However, the data for reprocessing of paper waste and the data for virgin paper production are highly variable. These differences are mainly related to different energy sources for the mills, both in regards to energy form (heat or electricity) and fuel (biomass or fossil fuels).

Hydroecology of Amazonian lacustrine Arcellinida (testate amoebae): A case study from Lake Quistococha, Peru.

PubMed

Patterson, R Timothy; Huckerby, Gail; Kelly, Thomas J; Swindles, Graeme T; Nasser, Nawaf A

2015-10-01

Organic rich sediments were obtained from seven core tops taken in Lake Quistococha, near the city of Iquitos in the Peruvian Amazon. Subsamples from 0 to 4cm depth in each core were analyzed under dissecting light microscopy to carry out the first investigation of Arcellinida (testate lobose amoebae) from a lacustrine environment in this ecologically important region. The fauna was characterized by a low diversity, low abundance community dominated by centropyxids. This fauna is similar to 'stressed' assemblages reported from temperate latitudes, except that test concentrations were two orders of magnitude lower than typical in temperate lakes. Principle arcellinidan stressors in Lake Quistococha likely include the low pH 4 conditions in the lake, and a general lack of suitable minerogenic material to construct tests in the organic rich lake substrate. The low pH conditions are the result of runoff and seepage of water high in dissolved organic carbon from the adjacent similarly low pH 4 terrestrial peatland. The dearth of minerogenic material is the result of the lake being isolated from riverine input for the past ∼2000 years, even during flooding events. Other limiting factors contributing to depressed arcellinidan populations may include nutrient supply, predation pressure, competition, and post-mortem taphonomic factors. Copyright © 2015 Elsevier GmbH. All rights reserved.

Thermoelectric properties of PEDOT nanowire/PEDOT hybrids.

PubMed

Zhang, Kun; Qiu, Jingjing; Wang, Shiren

2016-04-21

Freestanding poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires were synthesized by template-confined in situ polymerization, and then integrated into polystyrene sulfonate (PSS)-doped PEDOT and tosylate-doped PEDOT hosts, respectively. The hybrid morphologies were characterized by atomic force microscopy, indicating the homogeneous dispersion of PEDOT nanowires. The thermoelectric properties of the resultant hybrids were measured, and the power factor was found to be enhanced by 9-fold in comparison with PSS mixed with 5 vol% dimethyl sulfoxide while the low thermal conductivity was still maintained. Such a significant improvement could be attributed to the synergistic effects of interfacial energy filtering, component contributions, and changes of carrier concentrations in the host materials. Upon addition of 0.2 wt% PEDOT nanowires, the resultant composites demonstrated a power factor as high as 446.6 μW m(-1) K(-2) and the thermoelectric figure of merit could reach 0.44 at room temperature. The thermoelectric devices were investigated by using the PEDOT nanowire/PEDOT hybrid as a p-type leg and nitrogen-doped graphene as an n-type leg. The normalized power output was as high as ∼0.5 mW m(-2) for a temperature gradient of ΔT = 10.1 °C, indicating great potential for practical applications. These findings open up a new route towards high-performance organic thermoelectric materials and devices.

Cultural capital and smoking in young adults: applying new indicators to explore social inequalities in health behaviour.

PubMed

Gagné, Thierry; Frohlich, Katherine L; Abel, Thomas

2015-10-01

Associations between social status and health behaviours are well documented, but the mechanisms involved are less understood. Cultural capital theory may contribute to a better understanding by expanding the scope of inequality indicators to include individuals' knowledge, skills, beliefs and material goods to examine how these indicators impact individuals' health lifestyles. We explore the structure and applicability of a set of cultural capital indicators in the empirical exploration of smoking behaviour among young male adults. We analysed data from the Swiss Federal Survey of Adolescents (CH-X) 2010-11 panel of young Swiss males (n = 10 736). A set of nine theoretically relevant variables (including incorporated, institutionalized and objectified cultural capital) were investigated using exploratory factor analysis. Regression models were run to observe the association between factor scores and smoking outcomes. Outcome measures consisted of daily smoking status and the number of cigarettes smoked by daily smokers. Cultural capital indicators aggregated in a three-factor solution representing 'health values', 'education and knowledge' and 'family resources'. Each factor score predicted the smoking outcomes. In young males, scoring low on health values, education and knowledge and family resources was associated with a higher risk of being a daily smoker and of smoking more cigarettes daily. Cultural capital measures that include, but go beyond, educational attainment can improve prediction models of smoking in young male adults. New measures of cultural capital may thus contribute to our understanding of the social status-based resources that individuals can use towards health behaviours. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Directly alcohol-attributable mortality by industry and occupation in a Spanish Census cohort of economically active population.

PubMed

Pulido, José; Vallejo, Fernando; Alonso-López, Ignacio; Regidor, Enrique; Villar, Fernando; de la Fuente, Luis; Domingo-Salvany, Antonia; Barrio, Gregorio

2017-11-01

To assess disparities in directly alcohol-attributable (DAA) mortality by industry/occupation in Spain during 2002-2011 and the contribution of different socio-demographic factors, including socioeconomic position, to explain such disparity. Nationwide cohort study covering 16 million economically active people living in Spain in 2001. Deaths at age 25-64 were analyzed. Subjects were classified by employment status, industry and occupation at baseline. Poisson regression models were built, calculating rate ratios (RRs) compared to all employees or those in the education sector. DAA mortality was much higher in the unemployed than in employees (Crude RR: 2.4; 95% CI: 2.3-2.6) and varied widely across industries/occupations. Crude RRs>3.0 (p<0.05) compared to teachers were found in employees in extractive industries/fishing, agriculture/livestock, construction, catering/accommodation and protective services. Socio-demographic factors, especially age, gender and educational attainment contributed more to explain risk disparities than other factors or potential selection bias. However, after exhaustive sociodemographic adjustment, including education attainment and material wealth, a RR>1.33 (p<0.05) remained in unemployed, catering/accommodation employees and unskilled construction workers. RRs were significantly larger in women than men (p<0.05) among mineworkers/fishworkers/sailors (RR=8.6 vs. 1.2) and drivers (RR=3.7 vs. 1.0). The results could be extrapolated to all alcohol-attributable mortality since disparities for other strongly alcohol-related deaths, although smaller, were in the same direction. Given the wide occupational disparities in alcohol-attributable mortality, implementation of special measures to reduce this mortality in the highest risk groups is fully justified. Future research should better characterize the explanatory factors of disparities and their role in the causal chain. Copyright © 2017. Published by Elsevier B.V.

Theoretical temperature-dependent branching ratios and laser thresholds of the 3F4 to 3H6 levels of Tm(3+) in ten garnets

NASA Technical Reports Server (NTRS)

Filer, Elizabeth D.; Barnes, Norman P.; Morrison, Clyde A.

1991-01-01

The calculated energy levels, the branching ratios, and the estimated thresholds for thulium operating on the 3F4 to 3H6 transitions are reported. Garnet materials with the general formula A3B2C3O12 are evaluated. Calculations are performed for the A side under the assumption of D2 symmetry. X-ray data available in the literature are used to evaluate the crystal-field components, A sub nm. Even-n components are employed to calculate the crystal-field splittings within the manifold. Thermal occupation factors are determined in a straightforward manner using a Boltzmann distribution for the respective manifolds. Odd-n components are applied to calculate the transition probabilities for electric field transitions. It is determined that the magnetic dipole contributions to the transition probability are comparable to the electric dipole contributions in some cases. Thresholds as a function of the density of thulium atoms are calculated.

EMG Processing Based Measures of Fatigue Assessment during Manual Lifting.

PubMed

Shair, E F; Ahmad, S A; Marhaban, M H; Mohd Tamrin, S B; Abdullah, A R

2017-01-01

Manual lifting is one of the common practices used in the industries to transport or move objects to a desired place. Nowadays, even though mechanized equipment is widely available, manual lifting is still considered as an essential way to perform material handling task. Improper lifting strategies may contribute to musculoskeletal disorders (MSDs), where overexertion contributes as the highest factor. To overcome this problem, electromyography (EMG) signal is used to monitor the workers' muscle condition and to find maximum lifting load, lifting height and number of repetitions that the workers are able to handle before experiencing fatigue to avoid overexertion. Past researchers have introduced several EMG processing techniques and different EMG features that represent fatigue indices in time, frequency, and time-frequency domain. The impact of EMG processing based measures in fatigue assessment during manual lifting are reviewed in this paper. It is believed that this paper will greatly benefit researchers who need a bird's eye view of the biosignal processing which are currently available, thus determining the best possible techniques for lifting applications.

Factors contributing to intervention fidelity in a multi-site chronic disease self-management program

PubMed Central

Perrin, Karen M; Burke, Somer Goad; O'Connor, Danielle; Walby, Gary; Shippey, Claire; Pitt, Seraphine; McDermott, Robert J; Forthofer, Melinda S

2006-01-01

Background and objectives Disease self-management programs have been a popular approach to reducing morbidity and mortality from chronic disease. Replicating an evidence-based disease management program successfully requires practitioners to ensure fidelity to the original program design. Methods The Florida Health Literacy Study (FHLS) was conducted to investigate the implementation impact of the Pfizer, Inc. Diabetes Mellitus and Hypertension Disease Self-Management Program based on health literacy principles in 14 community health centers in Florida. The intervention components discussed include health educator recruitment and training, patient recruitment, class sessions, utilization of program materials, translation of program manuals, patient retention and follow-up, and technical assistance. Results This report describes challenges associated with achieving a balance between adaptation for cultural relevance and fidelity when implementing the health education program across clinic sites. This balance was necessary to achieve effectiveness of the disease self-management program. The FHLS program was implemented with a high degree of fidelity to the original design and used original program materials. Adaptations identified as advantageous to program participation are discussed, such as implementing alternate methods for recruiting patients and developing staff incentives for participation. Conclusion Effective program implementation depends on the talent, skill and willing participation of clinic staff. Program adaptations that conserve staff time and resources and recognize their contribution can increase program effectiveness without jeopardizing its fidelity. PMID:17067388

Toxicological Profiling of Highly Purified Single-Walled Carbon Nanotubes with Different Lengths in the Rodent Lung and Escherichia Coli.

PubMed

Wang, Xiang; Lee, Jae-Hyeok; Li, Ruibin; Liao, Yu-Pei; Kang, Joohoon; Chang, Chong Hyun; Guiney, Linda M; Mirshafiee, Vahid; Li, Linjiang; Lu, Jianqin; Xia, Tian; Hersam, Mark C; Nel, André E

2018-06-01

Carbon nanotubes (CNTs) exhibit a number of physicochemical properties that contribute to adverse biological outcomes. However, it is difficult to define the independent contribution of individual properties without purified materials. A library of highly purified single-walled carbon nanotubes (SWCNTs) of different lengths is prepared from the same base material by density gradient ultracentrifugation, designated as short (318 nm), medium (789 nm), and long (1215 nm) SWCNTs. In vitro screening shows length-dependent interleukin-1β (IL-1β) production, in order of long > medium > short. However, there are no differences in transforming growth factor-β1 production in BEAS-2B cells. Oropharyngeal aspiration shows that all the SWCNTs induce profibrogenic effects in mouse lung at 21 d postexposure, but there are no differences between tube lengths. In contrast, these SWCNTs demonstrate length-dependent antibacterial effects on Escherichia coli, with the long SWCNT exerting stronger effects than the medium or short tubes. These effects are reduced by Pluronic F108 coating or supplementing with glucose. The data show length-dependent effects on proinflammatory response in macrophage cell line and antibacterial effects, but not on collagen deposition in the lung. These data demonstrate that over the length scale tested, the biological response to highly purified SWCNTs is dependent on the complexity of the nano/bio interface. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Grain-size-yield stress relationship: Analysis and computation

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

Meyers, M.A.; Benson, D.J.; Fu, H.H.

1999-07-01

The seminal contributions of Julia Weertman to the understanding of the mechanical properties of nanocrystalline materials will be briefly outlined. A constitutive equation predicting the effect of grain size on the yield stress of metals, based on the model proposed by M.A. Meyers and E. Ashworth, is discussed and extended to the nanocrystalline regime. At large grain sizes, it has the Hall-Petch form, and in the nanocrystalline domain the slope gradually decreases until it asymptotically approaches the flow stress of the grain boundaries. The material is envisaged as a composite, comprised of the grain interior, with flow stress {sigma}{sub fB},more » and grain boundary work-hardened layer, with flow stress {sigma}{sub fGB}. Three principal factors contribute to the grain-boundary hardening: (1) the grain boundaries act as barriers to plastic flow; (2) the grain boundaries act as dislocation sources; and (3) elastic anisotropy causes additional stresses in grain-boundary surroundings. The predictions of this model are compared with experimental measurements over the mono, micro, and nanocrystalline domains. Computational predictions are made of plastic flow as a function of grain size incorporating elastic and plastic anisotropy as well as differences of dislocation accumulation rate in grain boundary regions and grain interiors. This is the first plasticity calculation that accounts for grain size effects in a physically-based manner. 58 refs., 7 figs., 1 tab.« less

[Cointegration test and variance decomposition for the relationship between economy and environment based on material flow analysis in Tangshan City Hebei China].

PubMed

2015-12-01

The material flow account of Tangshan City was established by material flow analysis (MFA) method to analyze the periodical characteristics of material input and output in the operation of economy-environment system, and the impact of material input and output intensities on economic development. Using econometric model, the long-term interaction mechanism and relationship among the indexes of gross domestic product (GDP) , direct material input (DMI), domestic processed output (DPO) were investigated after unit root hypothesis test, Johansen cointegration test, vector error correction model, impulse response function and variance decomposition. The results showed that during 1992-2011, DMI and DPO both increased, and the growth rate of DMI was higher than that of DPO. The input intensity of DMI increased, while the intensity of DPO fell in volatility. Long-term stable cointegration relationship existed between GDP, DMI and DPO. Their interaction relationship showed a trend from fluctuation to gradual ste adiness. DMI and DPO had strong, positive impacts on economic development in short-term, but the economy-environment system gradually weakened these effects by short-term dynamically adjusting indicators inside and outside of the system. Ultimately, the system showed a long-term equilibrium relationship. The effect of economic scale on economy was gradually increasing. After decomposing the contribution of each index to GDP, it was found that DMI's contribution grew, GDP's contribution declined, DPO's contribution changed little. On the whole, the economic development of Tangshan City has followed the traditional production path of resource-based city, mostly depending on the material input which caused high energy consumption and serous environmental pollution.

44 CFR 312.6 - Materials and facilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Materials and facilities. 312... OF HOMELAND SECURITY PREPAREDNESS USE OF CIVIL DEFENSE PERSONNEL, MATERIALS, AND FACILITIES FOR NATURAL DISASTER PURPOSES § 312.6 Materials and facilities. FEMA also contributes to the development and...

Risk factors for osteoarthritis and contributing factors to current arthritic pain in South Korean older adults.

PubMed

Lee, Kyoung Min; Chung, Chin Youb; Sung, Ki Hyuk; Lee, Seung Yeol; Won, Sung Hun; Kim, Tae Gyun; Choi, Young; Kwon, Soon Sun; Kim, Yeon Ho; Park, Moon Seok

2015-01-01

Although previous studies have focused on risk factors for osteoarthritis, there is some debate on this issue. Furthermore, associated factors with arthritic symptom (arthralgia) have not been sufficiently investigated, despite its clinical importance in the management of osteoarthritis. This study was performed to examine the risk factors for osteoarthritis and the contributing factors to current arthritic pain in older adults. The Fourth Korean National Health and Nutrition Examination Surveys was conducted in 2009. Therein, 720 males and 1008 females aged 65 years and older were included. Comprehensive data on habitual, socioeconomic, medical, nutritional, and psychological factors were collected along with the presence of osteoarthritis and arthritic pain. After univariate analysis, binary logistic regression analysis was performed to identify risk factors for osteoarthritis and contributing factors to current arthritic pain. Age (p=0.005), female gender (p<0.001), higher body mass index (BMI) (p<0.001), and osteoporosis (p<0.001) were significant risk factors for osteoarthritis, while higher education level (p=0.025) was a protective factor for osteoarthritis. Higher BMI (p=0.047), lack of weekly moderate intensity activity (p<0.001), and unfavorable subjective health status (p<0.001) were significant factors contributing to current arthritic pain among subjects with osteoarthritis. Both osteoarthritis and current arthritic pain adversely affected health related quality of life. Higher BMI, lack of weekly moderate intensity activity, and unfavorable subjective health status were significant factors contributing to current arthritic pain. More attention needs to be paid to psychiatric effects on osteoarthritis and joint related pain.

Factor analysis of submicron particle size distributions near a major United States-Canada trade bridge.

PubMed

Ogulei, David; Hopke, Philip K; Ferro, Andrea R; Jaques, Peter A

2007-02-01

A factor analytic model has been applied to resolve and apportion particles based on submicron particle size distributions downwind of a United States-Canada bridge in Buffalo, NY. The sites chosen for this study were located at gradually increasing distances downwind of the bridge complex. Seven independent factors were resolved, including four factors that were common to all of the five sites considered. The common factors were generally characterized by the existence of two or more number and surface area modes. The seven factors resolved were identified as follows: fresh tail-pipe diesel exhaust, local/street diesel traffic, aged/evolved diesel particles, spark-ignition gasoline emissions, background urban emissions, heavy-duty diesel agglomerates, and secondary/transported material. Submicron (<0.5 microm) and ultrafine (<0.1 microm) particle emissions downwind of the bridge were dominated by commercial diesel truck emissions. Thus, this study obtained size distinction between fresh versus aged vehicle exhaust and spark-ignition versus diesel emissions based on the measured high time-resolution particle number concentrations. Because this study mainly used particles <300 nm in diameter, some sources that would usually exhibit number modes >100 nm were not resolved. Also, the resolved profiles suggested that the major number mode for fresh tailpipe diesel exhaust might exist below the detection limit of the spectrometer used. The average particle number contributions from the resolved factors were highest closest to the bridge.

Environmental Effects on ISS Materials Aging (1998 to 2008)

NASA Technical Reports Server (NTRS)

Alred, John; Dasgupta, Rajib; Koontz, Steve; Soares, Carlos; Golden, John

2009-01-01

The performance of ISS spacecraft materials and systems on prolonged exposure to the low- Earth orbit (LEO) space flight are reported in this paper. In-flight data, flight crew observations, and the results of ground-based test and analysis directly supporting programmatic and operational decision-making are described. The space flight environments definitions (both natural and induced) used for ISS design, material selection, and verification testing are shown, in most cases, to be more severe than the actual flight environment accounting, in part, for the outstanding performance of ISS as a long mission duration spacecraft. No significant ISS material or system failures have been attributed to spacecraft-environments interactions. Nonetheless, ISS materials and systems performance data is contributing to our understanding of spacecraft material interactions with the spaceflight environment so as to reduce cost and risk for future spaceflight projects and programs. Orbital inclination (51.6 deg) and altitude (nominally near 360 km) determine the set of natural environment factors affecting the functional life of materials and systems on ISS. ISS operates in an electrically conducting environment (the F2 region of Earth s ionosphere) with well-defined fluxes of atomic oxygen, other charged and neutral ionospheric plasma species, solar UV, VUV, and x-ray radiation as well as galactic cosmic rays, trapped radiation, and solar cosmic rays. The LEO micrometeoroid and orbital debris environment is an especially important determinant of spacecraft design and operations. The magnitude of several environmental factors varies dramatically with latitude and longitude as ISS orbits the Earth. The high latitude orbital environment also exposes ISS to higher fluences of trapped energetic electrons, auroral electrons, solar cosmic rays, and galactic cosmic rays than would be the case in lower inclination orbits, largely as a result of the overall shape and magnitude of the geomagnetic field. As a result, ISS exposure to many environmental factors can vary dramatically along a particular orbital ground track, and from one ground track to the next, during any 24-hour period. The induced environment results from ISS interactions with the natural environment as well as environmental factors produced by ISS itself and visiting vehicles fleet. Examples include ram-wake effects, hypergolic thruster plume impingement, materials out-gassing, venting and dumping of fluids, and specific photovoltaic (PV) power system interactions with the ionospheric plasma (7-11). Vehicle size (L) and velocity (V), combined with the magnitude and direction of the geomagnetic field (B) produce operationally significant magnetic induction voltages (VxB.L) in ISS conducting structure during flight through high latitudes (> +45deg) during each orbit. Finally, an induced ionizing radiation environment is produced by cosmic ray interaction with the relatively thick ISS structure and shielding materials. The intent of this review article is, therefore, to provide a summary of selected aspects and elements of the ISS vehicle with regard to LEO space environment effects, associated with the much larger and more complicated vehicle that ISS has become since 1998, but also with an eye towards performance life extension to the year 2016 and beyond.

Exploring barriers and enablers for scaling up a community-based grain bank intervention for improved infant and young child feeding in Ethiopia: A qualitative process evaluation.

PubMed

Sako, Binta; Leerlooijer, Joanne N; Lelisa, Azeb; Hailemariam, Abebe; Brouwer, Inge D; Tucker Brown, Amal; Osendarp, Saskia J M

2018-04-01

Child malnutrition remains high in Ethiopia, and inadequate complementary feeding is a contributing factor. In this context, a community-based intervention was designed to provide locally made complementary food for children 6-23 months, using a bartering system, in four Ethiopian regions. After a pilot phase, the intervention was scaled up from 8 to 180 localities. We conducted a process evaluation to determine enablers and barriers for the scaling up of this intervention. Eight study sites were selected to perform 52 key informant interviews and 31 focus group discussions with purposely selected informants. For analysis, we used a framework describing six elements of successful scaling up: socio-political context, attributes of the intervention, attributes of the implementers, appropriate delivery strategy, the adopting community, and use of research to inform the scale-up process. A strong political will, alignment of the intervention with national priorities, and integration with the health care system were instrumental in the scaling up. The participatory approach in decision-making reinforced ownership at community level, and training about complementary feeding motivated mothers and women's groups to participate. However, the management of the complex intervention, limited human resources, and lack of incentives for female volunteers proved challenging. In the bartering model, the barter rate was accepted, but the bartering was hindered by unavailability of cereals and limited financial and material resources to contribute, threatening the project's sustainability. Scaling up strategies for nutrition interventions require sufficient time, thorough planning, and assessment of the community's capacity to contribute human, financial, and material resources. © 2017 The Authors. Maternal and Child Nutrition Published by John Wiley & Sons, Ltd.

Exploring barriers and enablers for scaling up a community‐based grain bank intervention for improved infant and young child feeding in Ethiopia: A qualitative process evaluation

PubMed Central

Sako, Binta; Leerlooijer, Joanne N.; Lelisa, Azeb; Hailemariam, Abebe; Brouwer, Inge D.; Tucker Brown, Amal

2017-01-01

Abstract Child malnutrition remains high in Ethiopia, and inadequate complementary feeding is a contributing factor. In this context, a community‐based intervention was designed to provide locally made complementary food for children 6–23 months, using a bartering system, in four Ethiopian regions. After a pilot phase, the intervention was scaled up from 8 to 180 localities. We conducted a process evaluation to determine enablers and barriers for the scaling up of this intervention. Eight study sites were selected to perform 52 key informant interviews and 31 focus group discussions with purposely selected informants. For analysis, we used a framework describing six elements of successful scaling up: socio‐political context, attributes of the intervention, attributes of the implementers, appropriate delivery strategy, the adopting community, and use of research to inform the scale‐up process. A strong political will, alignment of the intervention with national priorities, and integration with the health care system were instrumental in the scaling up. The participatory approach in decision‐making reinforced ownership at community level, and training about complementary feeding motivated mothers and women's groups to participate. However, the management of the complex intervention, limited human resources, and lack of incentives for female volunteers proved challenging. In the bartering model, the barter rate was accepted, but the bartering was hindered by unavailability of cereals and limited financial and material resources to contribute, threatening the project's sustainability. Scaling up strategies for nutrition interventions require sufficient time, thorough planning, and assessment of the community's capacity to contribute human, financial, and material resources. PMID:29063698

The assessment of ultrasonic tests as a tool for qualification and diagnostic study of traditional highly porous and soft stone materials used in the built heritage of the past.

NASA Astrophysics Data System (ADS)

Calia, A.; Sileo, M.; Leucci, G.

2012-04-01

Ultrasonic tests are performing tools for the quality assessment and selection of stone as building materials, as well as for the detection of faults within architectural and structural elements. The use of the non destructive and non invasive diagnostic techniques has always advantages in the activities on pre-existing buildings, in terms of sustainability; moreover, it is a need with respect to the conservation constraints when we act on the historical-architectural heritage. Ultrasonic technique is widely and successfully performed in the diagnosis and control of the restoration works on concrete and compact stone artefacts. Specific problems arise from its use with reference to highly porous and soft stones, in particular bi-component materials with grains-cement binder structure, such as calcarenites. Low ultrasonic propagation velocity, typically associated to the soft and porous materials can be easily affected by disturbing factors, in primis water (in vapour or liquid state), that can easily and frequently penetrates inside them and in significant amounts, due to their high open porosity. The analysis and interpretation of the data acquired by in situ investigations have to take into account this additional contribution. In the same way, on site structures and materials can be easily interested by salt presence and deposition within the pores, that can furtherly interfere on the data significance, as well as it is important to know the variability of data due to the different state of conservation of the stones. The influence of all these factors on the response to the ultrasonic tests needs to be investigated by laboratory controlled conditions, preliminarily to the in situ application. The present work refers to the experimental activity devoted to investigate the critical aspects that have been mentioned above and the results obtained. It is a part of a larger activity with the final aim to set up non invasive diagnostic procedures for the analysis and qualification of ancient masonries, realised with traditional soft stones, used as building materials in the Southern Italy. This activity is carried out within the AITECH network (Applied Innovation Technologies for Diagnosis and Conservation of Built Heritage), a regional research laboratory infrastructure (Apulian region, Southern Italy) funded within the FSE and FESR programs and realised by the contribution of the Italian CNR and Salento University. In particular, ultrasonic velocity propagation have been measured on different petrographic kinds of calcarenitic materials. The influence of the sample size -the scale effect- has also been investigated. Velocity data have been recorded on the samples in the following conditions: a) dry, wet and different rates of the humidity content b) salt saturation c) after ageing by salt crystallisation cycles. Finally, ultrasonic tests have been performed on some samples treated by inorganic silica consolidant. This experimental laboratory investigation is the preliminary activity to assess the performance potential of the ultrasonic tests as effective tool for the qualification and diagnosis before and after treatments, with reference to the specific critical aspects related to highly porous and soft stone materials, traditionally used in the built heritage of the past.

Associations between errors and contributing factors in aircraft maintenance

NASA Technical Reports Server (NTRS)

Hobbs, Alan; Williamson, Ann

2003-01-01

In recent years cognitive error models have provided insights into the unsafe acts that lead to many accidents in safety-critical environments. Most models of accident causation are based on the notion that human errors occur in the context of contributing factors. However, there is a lack of published information on possible links between specific errors and contributing factors. A total of 619 safety occurrences involving aircraft maintenance were reported using a self-completed questionnaire. Of these occurrences, 96% were related to the actions of maintenance personnel. The types of errors that were involved, and the contributing factors associated with those actions, were determined. Each type of error was associated with a particular set of contributing factors and with specific occurrence outcomes. Among the associations were links between memory lapses and fatigue and between rule violations and time pressure. Potential applications of this research include assisting with the design of accident prevention strategies, the estimation of human error probabilities, and the monitoring of organizational safety performance.

Haptic identification of objects and their depictions.

PubMed

Klatzky, R L; Loomis, J M; Lederman, S J; Wake, H; Fujita, N

1993-08-01

Haptic identification of real objects is superior to that of raised two-dimensional (2-D) depictions. Three explanations of real-object superiority were investigated: contribution of material information, contribution of 3-D shape and size, and greater potential for integration across the fingers. In Experiment 1, subjects, while wearing gloves that gently attenuated material information, haptically identified real objects that provided reduced cues to compliance, mass, and part motion. The gloves permitted exploration with free hand movement, a single outstretched finger, or five outstretched fingers. Performance decreased over these three conditions but was superior to identification of pictures of the same objects in all cases, indicating the contribution of 3-D structure and integration across the fingers. Picture performance was also better with five fingers than with one. In Experiment 2, the subjects wore open-fingered gloves, which provided them with material information. Consequently, the effect of type of exploration was substantially reduced but not eliminated. Material compensates somewhat for limited access to object structure but is not the primary basis for haptic object identification.

[Nutritional deficit in children in a major city of the interior of the state of Bahia, Brazil].

PubMed

de Jesus, Gilmar Mercês; Castelão, Elizia Simões; Vieira, Tatiana de Oliveira; Gomes, Daiene Rosa; Vieira, Graciete Oliveira

2014-05-01

The study sought to analyze the nutritional deficit of children and associated environmental factors and maternal and infant characteristics in a major city in the interior of the state of Bahia. Information from mother/child-under-four duos of a birth cohort was assessed. Malnutrition was defined by the height-for-age (H/A) anthropometric index, at a cutoff of -1 z-score relative to the benchmark of the 2006 Multicentre Growth Reference Study. The variables studied were: the characteristics of children (birth weight and multiple births) and mothers (age at the time of birth, education level, parity and performing prenatal exams) and environmental factors (floor and roof material of residence, source of water consumed, indoor plumbing, water used for consumption and ownership of a refrigerator). Logistic regression was used to identify factors associated with nutritional deficit. Nutritional deficit occurred in 24.6% of children. Underweight at birth, inadequate prenatal care, precarious nature of the floor of the home and no indoor plumbing were predictors of malnutrition among children in the study. Factors associated with malnutrition confirm the contribution of social issues in the genesis of malnutrition.

Extracts of Cordia gilletii de wild (Boraginaceae) quench the quorum sensing of Pseudomonas aeruginosa PAO1

PubMed Central

Okusa, Philippe N.; Rasamiravaka, Tsiry; Vandeputte, Olivier; Stévigny, Caroline; Jaziri, Mondher El; Duez, Pierre

2014-01-01

Aim: The fight against infectious diseases and antimicrobial resistances needs the exploration of new active compounds with new proprieties like disrupting quorum sensing (QS) mechanisms, which is a cell-to-cell communication that regulates bacterial virulence factors. In this work, leaves and root barks extracts of a Congolese medicinal plant, Cordia gilletii, were investigated for their effect on the production of Pseudomonas aeruginosa major virulence factors regulated by QS. Materials and Methods: The effect of C. gilletii extracts on virulence factors of P. aeruginosa PAO1 was studied by the evaluation of the production of pyocyanine, elastase and biofilm; and by the measurement of the expression of QS-related genes. Results: The dichloromethane extract from root barks was found to quench the production of pyocyanin, a QS-dependent virulence factor in P. aeruginosa PAO1. Moreover, this extract specifically inhibits the expression of several QS-regulated genes (i.e. lasB, rhlA, lasI, lasR, rhlI, and rhlR) and reduces biofilm formation by PAO1. Conclusion: This study contributes to explain the efficacy of C. gilletii in the traditional treatment of infectious diseases caused by P. aeruginosa. PMID:26401363

Recent global trends in structural materials research

NASA Astrophysics Data System (ADS)

Murakami, Hideyuki; Ohmura, Takahito; Nishimura, Toshiyuki

2013-02-01

Structural materials support the basis of global society, such as infrastructure and transportation facilities, and are therefore essential for everyday life. The optimization of such materials allows people to overcome environmental, energy and resource depletion issues on a global scale. The creation and manufacture of structural materials make a large contribution to economies around the world every year. The use of strong, resistant materials can also have profound social effects, providing a better quality of life at both local and national levels. The Great East Japan Earthquake of 11 March 2011 caused significant structural damage in the Tohoku and Kanto regions of Japan. On a global scale, accidents caused by the ageing and failure of structural materials occur on a daily basis. Therefore, the provision and inspection of structural reliability, safety of nuclear power facilities and construction of a secure and safe society hold primary importance for researchers and engineers across the world. Clearly, structural materials need to evolve further to address both existing problems and prepare for new challenges that may be faced in the future. With this in mind, the National Institute for Materials Science (NIMS) organized the 'NIMS Conference 2012' to host an extensive discussion on a variety of global issues related to the future development of structural materials. Ranging from reconstruction following natural disasters, verification of structural reliability, energy-saving materials to fundamental problems accompanying the development of materials for high safety standards, the conference covered many key issues in the materials industry today. All the above topics are reflected in this focus issue of STAM, which introduces recent global trends in structural materials research with contributions from world-leading researchers in this field. This issue covers the development of novel alloys, current methodologies in the characterization of structural materials and fundamental research on structure-property relationships. We are grateful to the authors who contributed to cover these issues, and sincerely hope that our readers will expand their knowledge of emerging international research within the field of structural materials.

Linking biofilm growth to fouling and aeration performance of fine-pore diffuser in activated sludge.

PubMed

Garrido-Baserba, Manel; Asvapathanagul, Pitiporn; McCarthy, Graham W; Gocke, Thomas E; Olson, Betty H; Park, Hee-Deung; Al-Omari, Ahmed; Murthy, Sudhir; Bott, Charles B; Wett, Bernhard; Smeraldi, Joshua D; Shaw, Andrew R; Rosso, Diego

2016-03-01

Aeration is commonly identified as the largest contributor to process energy needs in the treatment of wastewater and therefore garners significant focus in reducing energy use. Fine-pore diffusers are the most common aeration system in municipal wastewater treatment. These diffusers are subject to fouling and scaling, resulting in loss in transfer efficiency as biofilms form and change material properties producing larger bubbles, hindering mass transfer and contributing to increased plant energy costs. This research establishes a direct correlation and apparent mechanistic link between biofilm DNA concentration and reduced aeration efficiency caused by biofilm fouling. Although the connection between biofilm growth and fouling has been implicit in discussions of diffuser fouling for many years, this research provides measured quantitative connection between the extent of biofouling and reduced diffuser efficiency. This was clearly established by studying systematically the deterioration of aeration diffusers efficiency during a 1.5 year period, concurrently with the microbiological study of the biofilm fouling in order to understand the major factors contributing to diffuser fouling. The six different diffuser technologies analyzed in this paper included four different materials which were ethylene-propylene-diene monomer (EPDM), polyurethane, silicone and ceramic. While all diffusers foul eventually, some novel materials exhibited fouling resistance. The material type played a major role in determining the biofilm characteristics (i.e., growth rate, composition, and microbial density) which directly affected the rate and intensity at what the diffusers were fouled, whereas diffuser geometry exerted little influence. Overall, a high correlation between the increase in biofilm DNA and the decrease in αF was evident (CV < 14.0 ± 2.0%). By linking bacterial growth with aeration efficiency, the research was able to show quantitatively the causal connection between bacterial fouling and energy wastage during aeration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of Fluoride Retention Due to Most Commonly Consumed Estuarine Fishes Among Fish Consuming Population of Andhra Pradesh as a Contributing Factor to Dental Fluorosis: A Cross-Sectional Study

PubMed Central

Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Sidiq, Mohsin; Singh, Kushpal; Vishnani, Preeti

2015-01-01

Background Fluoride in drinking water is known for both beneficial and detrimental effects on health. The principal sources of fluoride include water, some species of vegetation, certain edible marine animals, dust and industrial processes. The purpose of this study was to evaluate the fluoride retention of most commonly consumed estuarine fishes among fish consuming population of Andhra Pradesh. Materials and Methods A cross-sectional study was conducted to evaluate the amount of fluoride retention due to ten most commonly consumed estuarine fishes as a contributing factor to Fluorosis by SPADNS Spectrophotometric method. The presence and severity of dental fluorosis among fish consuming population was recorded using Community Fluorosis Index. Statistical analysis was done using MedCalc v12.2.1.0 software. Results For Sea water fishes, the fluoride levels in bone were maximum in Indian Sardine (4.22 ppm). Amongst the river water fishes, the fluoride levels in bone were maximum in Catla (1.51 ppm). Also, the mean total fluoride concentrations of all the river fishes in skin, muscle and bone were less (0.86 ppm) as compared to the sea water fishes (2.59 ppm). It was unveiled that sea fishes accumulate relatively large amounts of Fluoride as compared to the river water fishes. The mean Community Fluorosis Index was found to be 1.06 amongst a sampled fish consuming population. Evaluation by Community Index for Dental fluorosis (CFI) suggested that fluorosis is of medium public health importance. Conclusion It was analysed that bone tends to accumulate more amount of fluoride followed by muscle and skin which might be due to the increased permeability and chemical trapping of fluoride inside the tissues. The amount of fluoride present in the fishes is directly related to the severity of fluorosis amongst fish consuming population, suggesting fishes as a contributing factor to fluorosis depending upon the dietary consumption. PMID:26266208

Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

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

Callan, J.R.; Gwynne, J.W. III; Kelly, T.T.

1995-05-01

A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task.more » The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses.« less

The Corfu Landslide: Analog to Giant Landslides on Mars

NASA Technical Reports Server (NTRS)

Lewis, S. W.; Baker, V. R.

1984-01-01

In an analog to the great landslides of the Vales Marineris, Mars, a detailed study was made of the Corfu Landslide in south-central Washington. This prehistoric slide is located on the northern flank of the Saddle Mountains, southwest of Othello, Washington. The slide covers a 13 square km area centered on section 11 of T.15N., R.27E., Willamette Meridian, adjacent to the Corfu townsite. Approximately 1 cubic km of material is involved in sliding that was probably initiated by Missoula flooding through the Channeled Scabland. It is concluded that there were four primary factors involved in the initiation of the Corfu landsliding: (1) A slip surface was present at the right orientation; (2) Glacial flooding undercut the slope; (3) Wetter climatic conditions prevailed during that time period; and (4) Some seismic vibrations, known to occur locally, probably acted as a trigger. These factors show that special conditions were required in conjunction to produce landsliding. Studies in progress of the Vales Marieneris suggest that the same factors probably contributed to landsliding there.

Smooth seaward-dipping horizons - An important factor in sea-floor stability?

USGS Publications Warehouse

McGregor, B.A.

1981-01-01

Mass movement has influenced in varying degrees the morphology of the United States east coast continental margin seaward of the Baltimore Canyon trough as revealed by detailed geophysical studies using high-resolution 3.5-kHz, and seismic reflection data. Each of three areas studied is along the slope within a distance of 225 km, and is seaward of a nonglaciated shelf but near major land drainage systems. Thick sequences of material believed to be Pleistocene were deposited on the slope in all three areas. Sediment failure in the form of large block movement involving block thicknesses of more than 100 m, however, has taken place in only two of the areas. A factor common to the two areas where failure took place, but absent in the area where no failure took place, is smooth seaward-dipping sub-bottom horizons. Whatever the triggering mechanism, a smooth slip surface that has a seward slope may contribute to mass movement by reducing the internal friction. This may be one of several factors that should be considered in assessing slope stability. ?? 1981.

Evaluation of recycling programmes in household waste collection systems.

PubMed

Dahlén, Lisa; Lagerkvist, Anders

2010-07-01

A case study and a literature review have been carried out to address the two questions: how can waste flow data from collection systems be interpreted and compared? and which factors are decisive in the results of recycling programmes in household waste collection systems? The aim is to contribute to the understanding of how recycling programmes affect the quantity of waste and sorting activities. It is shown how the results from various waste sorting systems can be interpreted and made comparable. A set of waste flow indicators is proposed, which together with generic system descriptions can facilitate comparisons of different collections systems. The evaluation of collection systems depends on the system boundaries and will always be site-specific to some degree. Various factors are relevant, e.g. environmental objectives, technical function, operating costs, types of recyclable materials collected separately, property-close collection or drop-off systems, economic incentives, information strategies, residential structure, social codes, etc. Kerbside collection of recyclables and weight-based billing led to increased waste sorting activities in the case study. Forty-three decisive factors are listed and discussed.

Contributing factors in construction accidents.

PubMed

Haslam, R A; Hide, S A; Gibb, A G F; Gyi, D E; Pavitt, T; Atkinson, S; Duff, A R

2005-07-01

This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

Hazardous Material Transportation Risks in the Puget Sound Region

DOT National Transportation Integrated Search

1981-09-01

In order to contribute to workable hazardous materials accident prevention and response systems, public safety risks of transporting hazardous materials in the Central Puget Sound Region of Washington State are determined. Risk spectrums are obtained...

Anthropometry, carbohydrate and lipid metabolism in the East Flanders Prospective Twin Survey: heritabilities

PubMed Central

Souren, N. Y.; Loos, R. J. F.; Gielen, M.; Beunen, G.; Fagard, R.; Derom, C.; Vlietinck, R.; Zeegers, M. P.

2007-01-01

Aims/hypothesis We determined the genetic contribution of 18 anthropometric and metabolic risk factors of type 2 diabetes using a young healthy twin population. Methods Traits were measured in 240 monozygotic (MZ) and 138 dizygotic (DZ) twin pairs aged 18 to 34 years. Twins were recruited from the Belgian population-based East Flanders Prospective Twin Survey, which is characterised by its accurate zygosity determination and extensive collection of perinatal and placental data, including information on chorionicity. Heritability was estimated using structural equation modelling implemented in the Mx software package. Results Intra-pair correlations of the anthropometric and metabolic characteristics did not differ between MZ monochorionic and MZ dichorionic pairs; consequently heritabilities were estimated using the classical twin approach. For body mass, BMI and fat mass, quantitative sex differences were observed; genetic variance explained 84, 85 and 81% of the total variation in men and 74, 75 and 70% in women, respectively. Heritability estimates of the waist-to-hip ratio, sum of four skinfold thicknesses and lean body mass were 70, 74 and 81%, respectively. The heritability estimates of fasting glucose, fasting insulin, homeostasis model assessment of insulin resistance and beta cell function, as well as insulin-like growth factor binding protein-1 levels were 67, 49, 48, 62 and 47%, in that order. Finally, for total cholesterol, LDL-cholesterol, HDL-cholesterol, total cholesterol:HDL-cholesterol ratio, triacylglycerol, NEFA and leptin levels, genetic factors explained 75, 78, 76, 79, 58, 37 and 53% of the total variation, respectively. Conclusions/interpretation Genetic factors explain the greater part of the variation in traits related to obesity, glucose intolerance/insulin resistance and dyslipidaemia. Electronic supplementary material The online version of this article (doi:10.1007/s00125-007-0784-z) contains supplementary material, which is available to authorised users. PMID:17694296

Hybrid photovoltaic-thermoelectric system for concentrated solar energy conversion: Experimental realization and modeling

NASA Astrophysics Data System (ADS)

Beeri, Ofer; Rotem, Oded; Hazan, Eden; Katz, Eugene A.; Braun, Avi; Gelbstein, Yaniv

2015-09-01

An experimental demonstration of the combined photovoltaic (PV) and thermoelectric conversion of concentrated sunlight (with concentration factor, X, up to ˜300) into electricity is presented. The hybrid system is based on a multi-junction PV cell and a thermoelectric generator (TEG). The latter increases the electric power of the system and dissipates some of the excessive heat. For X ≤ 200, the system's maximal efficiency, ˜32%, was mostly due to the contribution from the PV cell. With increasing X and system temperature, the PV cell's efficiency decreased while that of the TEG increased. Accordingly, the direct electrical contribution of the TEG started to dominate in the total system power, reaching ˜20% at X ≈ 290. Using a simple steady state finite element modeling, the cooling effect of the TEG on the hybrid system's efficiency was proved to be even more significant than its direct electrical contribution for high solar concentrations. As a result, the total efficiency contribution of the TEG reached ˜40% at X ≈ 200. This suggests a new system optimization concept that takes into account the PV cell's temperature dependence and the trade-off between the direct electrical generation and cooling capabilities of the TEG. It is shown that the hybrid system has a real potential to exceed 50% total efficiency by using more advanced PV cells and TE materials.

Gender Difference in Aerobic Capacity and the Contribution by Body Composition and Haemoglobin Concentration: A Study in Young Indian National Hockey Players

PubMed Central

Kailashiya, Jyotsna

2016-01-01

Introduction Although gender difference in aerobic capacity is known, the contributing factors have been researched seldom. Aim To investigate the gender gap and the contribution by percentage Body Fat (BF), Body Mass Index (BMI) and haemoglobin concentration Hb. Materials and Methods The study was conducted on 30 (17 males, 13 females) training status matched young hockey players. Healthy players who were playing upto national level competition were included. BW (Body Weight), BF, BMI, LBM (Lean Body Mass), rHR (restring Heart Rate), HRR (Heart Rate Recovery), Hb, a/rVO2max (absolute/relative), a/rPWC (Physical Work Capacity) and RMR (Resting Metabolic Rate) were measured and analysed. Results There was significant gender difference in the measured parameters. Difference in a/rVO2max remained significant even after controlling for BF, BMI and Hb. Multiple regression and correlation analysis revealed gender difference in VO2max/LBM was due to: BMI(31.91%)>BF(27.60%)>Hb(9.91%). BMI also significantly contributed 3.66% of VO2max/LBM variance, independent of that by gender. Difference in RMR was mainly related to LBM, BF and BMI. Conclusion The study provided an understanding for gender gap in aerobic capacity. Differences in BMI & BF were one of the main reasons. PMID:28050360

Adjustment of Children Born to Teenage Mothers: The Contribution of Risk and Protective Factors.

ERIC Educational Resources Information Center

Dubow, Eric F.; Luster, Tom

1990-01-01

Examined contribution of risk and protective factors in adjustment of 721 children, age 8-15, born to teenage mothers. Results showed that exposure to increasing number of risk factors (poverty, urban residence, mother's self-esteem) was associated with greater vulnerability to adjustment problems, while protective factors (intelligence,…

Light absorption by coated nano-sized carbonaceous particles

NASA Astrophysics Data System (ADS)

Gangl, Martin; Kocifaj, Miroslav; Videen, Gorden; Horvath, Helmuth

The optical properties of strongly absorbing soot particles coated by transparent material are investigated experimentally and described by several modeling approaches. Soot is produced by spark discharge and passed through a Sinclair-La Mer generator where non-absorbing carnauba wax is condensed onto it to obtain internal soot-wax mixtures in a controlled way. Measurements of the extinction and volume scattering coefficient show an amplification of absorption by a factor of approximately 1.8. This behavior was described by different approaches of internally mixed materials for the modal diameters of the measured size distributions: concentric-sphere model, effective medium approximations and heterogeneous ellipsoids. The concentric-sphere model describes the absorption increase quantitatively; and hence, it is chosen to be applied to the entire particle population in the size distribution. The growth of the soot particles by condensing wax is described by a simplified growth model to estimate the different contributions of several soot particle diameters to the overall absorption cross-section.

Industrial processing versus home cooking: an environmental comparison between three ways to prepare a meal.

PubMed

Sonesson, Ulf; Mattsson, Berit; Nybrant, Thomas; Ohlsson, Thomas

2005-06-01

Today there is a strong trend in Sweden for industrially processed meals to replace homemade meals. In the public debate this is often claimed to increase the environmental impact from foods. In the study presented in this article, we used life-cycle assessment to quantify the environmental impact of three meals: homemade, semiprepared, and ready-to-eat. The differences in environmental impact between the meals were small; the ready-to-eat meal used the most energy, whereas the homemade meal had higher emissions causing eutrophication and global warming. The dominating contributor to the environmental impact was agriculture, accounting for 30%, of the impact related to energy and 95% of that related to eutrophication. Industry, packaging, and consumer home transport and food preparation also contributed significantly. Important factors were raw material use, energy efficiency in industry and households, packaging, and residue treatment. To decrease the overall environmental impact of food consumption, improvements in agriculture are very important, together with raw-material use within industry and households.

High temperature dielectric properties of Apical, Kapton, Peek, Teflon AF, and Upilex polymers

NASA Technical Reports Server (NTRS)

Hammoud, A. N.; Baumann, E. D.; Overton, E.; Myers, I. T.; Suthar, J. L.; Khachen, W.; Laghari, J. R.

1992-01-01

Reliable lightweight systems capable of providing electrical power at the magawatt level are a requirement for future manned space exploration missions. This can be achieved by the development of high temperature insulating materials which are not only capable of surviving the hostile space environment but can contribute to reducing the mass and weight of the heat rejection system. In this work, Apical, Upilex, Kapton, Teflon AF, and Peek polymers are characterized for AC and DC dielectric breakdown in air and in silicone oil at temperatures up to 250 C. The materials are also tested in terms of their dielectric constant and dissipation factor at high temperatures with an electrical stress of 60 Hz, 200 V/mil present. The effects of thermal aging on the properties of the films are determined after 15 hours of exposure to 200 and 250 C, each. The results obtained are discussed and conclusions are made concerning the suitability of these dielectrics for use in capacitors and cable insulations in high temperature environments.

Comparative shock response of additively manufactured versus conventionally wrought 304L stainless steel

NASA Astrophysics Data System (ADS)

Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.; Palmer, T. A.

2017-01-01

Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens that were machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology permits direct fabrication of net- or near-net-shape metal parts. For the present investigation, velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response for one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.0 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. The possible contributions of various factors, such as composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and/or sample axis orientation relative to the additive manufacturing deposition trajectory, are considered to explain differences between the AM and baseline 304L dynamic material results.