Sample records for absorption index wai

  1. Development of WAIS-III General Ability Index Minus WMS-III memory discrepancy scores.

    PubMed

    Lange, Rael T; Chelune, Gordon J; Tulsky, David S

    2006-09-01

    Analysis of the discrepancy between intellectual functioning and memory ability has received some support as a useful means for evaluating memory impairment. In recent additions to Wechlser scale interpretation, the WAIS-III General Ability Index (GAI) and the WMS-III Delayed Memory Index (DMI) were developed. The purpose of this investigation is to develop base rate data for GAI-IMI, GAI-GMI, and GAI-DMI discrepancy scores using data from the WAIS-III/WMS-III standardization sample (weighted N = 1250). Base rate tables were developed using the predicted-difference method and two simple-difference methods (i.e., stratified and non-stratified). These tables provide valuable data for clinical reference purposes to determine the frequency of GAI-IMI, GAI-GMI, and GAI-DMI discrepancy scores in the WAIS-III/WMS-III standardization sample.

  2. WAIS-III index score profiles in the Canadian standardization sample.

    PubMed

    Lange, Rael T

    2007-01-01

    Representative index score profiles were examined in the Canadian standardization sample of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). The identification of profile patterns was based on the methodology proposed by Lange, Iverson, Senior, and Chelune (2002) that aims to maximize the influence of profile shape and minimize the influence of profile magnitude on the cluster solution. A two-step cluster analysis procedure was used (i.e., hierarchical and k-means analyses). Cluster analysis of the four index scores (i.e., Verbal Comprehension [VCI], Perceptual Organization [POI], Working Memory [WMI], Processing Speed [PSI]) identified six profiles in this sample. Profiles were differentiated by pattern of performance and were primarily characterized as (a) high VCI/POI, low WMI/PSI, (b) low VCI/POI, high WMI/PSI, (c) high PSI, (d) low PSI, (e) high VCI/WMI, low POI/PSI, and (f) low VCI, high POI. These profiles are potentially useful for determining whether a patient's WAIS-III performance is unusual in a normal population.

  3. Psychometric properties of the Thai version of the work ability index (Thai WAI).

    PubMed

    Kaewboonchoo, Orawan; Ratanasiripong, Paul

    2015-01-01

    The purpose of this research was to develop and test the psychometric properties of the Thai version of the Work Ability Index (WAI). Forward translation and back-translation of the WAI were performed by seven bilingual professionals to ensure that the Thai WAI was culturally relevant and conceptually accurate. To ensure generalizability of the Thai WAI, a sample of 2,744 Thai workers from 19 different enterprises in five regions of Thailand completed the Thai version of the WAI along with the General Health Questionnaire. The 19 enterprises were from the following industries: canned food, snack food, cooking oil, footwear, pharmaceutical, ceramics, toy, steel, petrochemical, and auto parts. The results from exploratory factor analysis supported a 3-factor model, accounting for 53.49% of the total variance. The results also provided evidence for adequate test-retest reliability and internal consistency of the Thai WAI. The internal consistency of the Thai WAI was found to be slightly low due to the newness of the concept of work ability, which is not a common term used in the Thai language; therefore, explanation of the meaning of work ability is needed to increase understanding of workers. By providing early recognition of workers' health risks as well as risks of early termination, the WAI can help Thai human resources managers respond better to the needs of workers and be proactive in their efforts to retain workers in their organizations. Occupational health professionals could also utilize the WAI to evaluate the work ability of Thai workers in order to help organizations recognize early signs of their workers' health risks and possible early terminations and respond appropriately.

  4. Work Ability Index (WAI) and its health-related determinants among Iranian farmers working in small farm enterprises.

    PubMed

    Rostamabadi, Akbar; Mazloumi, Adel; Rahimi Foroushani, Abbas

    2014-01-01

    This study aimed to determine the Work Ability Index (WAI) and examine the influence of health dimensions and demographic variables on the work ability of Iranian farmers working in small farm enterprises. A cross-sectional study was conducted among 294 male farmers. The WAI and SF-36 questionnaires were used to determine work ability and health status. The effect of demographics variables on the work ability index was investigated with the independent samples t-test and one-way ANOVA. Also, multiple linear regression analysis was used to test the association between the mean WAI score and the SF-36 scales. The mean WAI score was 35.1 (SD=10.6). One-way ANOVA revealed a significant relationship between the mean WAI and age. Multiple linear regression analysis showed that work ability was more influenced by physical scales of the health dimensions, such as physical function, role-physical, and general health, whereas a lower association was found for mental scales such as mental health. The average WAI was at a moderate work ability level for the sample population of farmers in this study. Based on the WAI guidelines, improvement of work ability and identification of factors affecting it should be considered a priority in interventional programs. Given the influence of health dimensions on WAI, any intervention program for preservation and promotion of work ability among the studied farmers should be based on balancing and optimizing the physical and psychosocial work environments, with a special focus on reducing physical work load.(J Occup Health 2014; 56: 478-484).

  5. Factors associated with work ability index (WAI) among intensive care units' (ICUs') nurses.

    PubMed

    Rostamabadi, Akbar; Zamanian, Zahra; Sedaghat, Zahra

    2017-03-28

    Work ability is a crucial occupational health issue in health care settings where a high physical and psychosocial work capacity is required and a high risk of disabling injuries and illnesses is predictable. This study aims to examine the association between the work ability index (WAI) and individual characterizations, workload, fatigue, and diseases among intensive care units' (ICUs') nurses. The study sample included 214 nurses selected by a random sampling method from a target population consisting of 321 registered nurses working in eight ICUs. Multiple linear regression analysis was used to test the association between WAI scores and each of the independent variables. Results of multivariate analysis revealed a strong and negative association between WAI scores and diseases (B=-5.82, 95% CI=-7.16, -4.48, P<0.001). Among the studied individual characterizations, body mass index (BMI) was significantly and inversely associated with WAI scores. A significant and negative association was also found between WAI scores and dimensions of MFI-20, such as general fatigue (B=-0.31, 95% CI=-0.53, -0.09, P=0.005) and physical fatigue (B=-0.44, 95% CI=-0.65, -0.23, P<0.001). From dimensions of workload, frustration (B=-0.04, 95% CI=-0.07, -0.02, P<0.001) and temporary demand (B=-0.04, 95% CI=-0.08, -0.0001, P=0.04) showed a negative and significant association with WAI scores, while performance showed a positive and significant association (B=0.04, 95% CI=0.01, 0.07, P=0.005). Based on the study findings, development of health care programs with the aim of setting up a healthy work environment characterized by a well-structured preventive attitude toward controlling diseases, and a well-designed organizational framework toward increasing the level of performance and motivation, reducing the level of fatigue, as well as reducing the workload, is necessary to promote work ability among ICUs' nurses.

  6. Comparison of WAIS-III Short Forms for Measuring Index and Full-Scale Scores

    ERIC Educational Resources Information Center

    Girard, Todd A.; Axelrod, Bradley N.; Wilkins, Leanne K.

    2010-01-01

    This investigation assessed the ability of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) short forms to estimate both index and IQ scores in a large, mixed clinical sample (N = 809). More specifically, a commonly used modification of Ward's seven-subtest short form (SF7-A), a recently proposed index-based SF7-C and eight-subtest…

  7. Work ability index (WAI) and its association with psychosocial factors in one of the petrochemical industries in Iran.

    PubMed

    Mazloumi, Adel; Rostamabadi, Akbar; Nasl Saraji, Gabraeil; Rahimi Foroushani, Abbas

    2012-01-01

    In recent decades, work ability index (WAI) has been a common practical tool to measure individuals' work ability in many European, Asian and South American countries. However, there is no study concerning work ability in Iran. The aim of this study was to determine the work ability index in an Iranian petrochemical job setting and to examine its relationship with psychosocial factors. A cross-sectional study was conducted among 420 male workers in various occupations. Work ability was evaluated using the WAI questionnaire developed by FIOH; the Job content questionnaire (JCQ) was used to assess psychosocial factors. The mean WAI score was 39.1 (SD=5.7) among workers in the studied petrochemical industry. Multiple linear regression analysis revealed a significant association between mean WAI score and age, job tenure, educational level, rest and sleep status and vocational education. Moreover, the results showed that skill discretion, coworker support and supervisor support were positively associated with the mean WAI score. On the other hand, it was inversely associated with job demands, job strain and job insecurity. This study was the first research to determine WAI in an important industry in Iran. Overall, work ability was in the "Good" category among the workers in the studied field. On the basis of the WAI guidelines, this level should be maintained and promoted to excellent level by providing supportive countermeasures. The WAI score was significantly associated with psychosocial factors. The results showed that even in heavy physical work, factors such as job insecurity, skill discretion, job strain and social support play an important role in maintaining work ability. A positive combination of "psychosocial characteristics" of the job with "individual resources" can promote work ability in such occupations.

  8. The psychometric properties of an Iranian translation of the Work Ability Index (WAI) questionnaire.

    PubMed

    Abdolalizadeh, M; Arastoo, A A; Ghsemzadeh, R; Montazeri, A; Ahmadi, K; Azizi, A

    2012-09-01

    This study was carried out to evaluate the psychometric properties of an Iranian translation of the Work Ability Index (WAI) questionnaire. In this methodological study, nurses and healthcare workers aged 40 years and older who worked in educational hospitals in Ahvaz (236 workers) in 2010, completed the questionnaire and 60 of the workers filled out the WAI questionnaire for the second time to ensure test-retest reliability. Forward-backward method was applied to translate the questionnaire from English into Persian. The psychometric properties of the Iranian translation of the WAI were assessed using the fallowing tests: Internal consistency (to test reliability), test-retest analysis, exploratory factor analysis (construct validity), discriminate validity by comparing the mean WAI score in two groups of the employees that had different levels of sick leave, criterion validity by determining the correlation between the Persian version of short form health survey (SF-36) and WAI score. Cronbach's alpha coefficient was estimated to be 0.79 and it was concluded that the internal consistency was high enough. The intraclass correlation coefficient was recognized to be 0.92. Factor analysis indicated three factors in the structure of the work ability including self-perceived work ability (24.5% of the variance), mental resources (22.23% of the variance), and presence of disease and health related limitation (18.55% of the variance). Statistical tests showed that this questionnaire was capable of discriminating two groups of employees who had different levels of sick leave. Criterion validity analysis showed that this instrument and all dimensions of the Iranian version of SF-36 were correlated significantly. Item correlation corrective for overlap showed the items tests had a good correlation except for one. The finding of the study showed that the Iranian version of the WAI is a reliable and valid measure of work ability and can be used both in research and practical

  9. Comparability of WAIS and WAIS--R scores among mentally retarded adults.

    PubMed

    Raggio, D J

    1989-08-01

    This study compared the performance on the WAIS and WAIS--R of 21 mentally retarded adults residing in an Intermediate Care Facility. Tests were administered in one order, the WAIS initially and the WAIS--R second, with approximately two years between testings. Significant differences were found on the WAIS and WAIS--R for Verbal, Performance and Full Scale IQs. This finding contrasts with the differences between the measures as reported in the WAIS--R manual.

  10. Independent examination of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV): what does the WAIS-IV measure?

    PubMed

    Benson, Nicholas; Hulac, David M; Kranzler, John H

    2010-03-01

    Published empirical evidence for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) does not address some essential questions pertaining to the applied practice of intellectual assessment. In this study, the structure and cross-age invariance of the latest WAIS-IV revision were examined to (a) elucidate the nature of the constructs measured and (b) determine whether the same constructs are measured across ages. Results suggest that a Cattell-Horn-Carroll (CHC)-inspired structure provides a better description of test performance than the published scoring structure does. Broad CHC abilities measured by the WAIS-IV include crystallized ability (Gc), fluid reasoning (Gf), visual processing (Gv), short-term memory (Gsm), and processing speed (Gs), although some of these abilities are measured more comprehensively than are others. Additionally, the WAIS-IV provides a measure of quantitative reasoning (QR). Results also suggest a lack of cross-age invariance resulting from age-related differences in factor loadings. Formulas for calculating CHC indexes and suggestions for interpretation are provided. PsycINFO Database Record (c) 2010 APA, all rights reserved.

  11. An exploratory study of the Work Ability Index (WAI) and its components in a group of computer workers.

    PubMed

    Costa, Ana Filipa; Puga-Leal, Rogério; Nunes, Isabel L

    2011-01-01

    The objective of this paper is to present a study on the assessment of the work ability of a group of aged computers workers. The study was developed with the goal of creating a decision making framework oriented towards the maintenance of the health and working ability of aged workers. Fifty computer workers participated in this study. They were administrative secretaries and computer technicians working mainly with office computers. The method used to assess the work ability was the Work Ability Index (WAI). 78% of the participants had good or excellent work ability and only 2% a poor one. The average WAI score was 40.5 (SD=5.761; min=27; max=49). This study confirms the decrease in work ability of workers while aging. The group overall work ability was slightly higher than the reference values develop by the Finnish Institute of Occupational Health. The assessment of work ability is fundamental to make age-friendly workplaces. WAI is one tool designed to perform such assessment. The results obtained could assist the early identification of situations where employees are struggling with their work ability, thus helping to prioritize ergonomic interventions devoted to improve the working conditions, and allowing the continued employment of aging workers on their current job.

  12. WAIS-IV Seven-Subtest Short Form: Validity and Clinical Use in Schizophrenia.

    PubMed

    Bulzacka, Ewa; Meyers, John E; Boyer, Laurent; Le Gloahec, Tifenn; Fond, Guillaume; Szöke, Andrei; Leboyer, Marion; Schürhoff, Franck

    2016-09-01

    This study assesses the psychometric properties of Ward's seven-subtest short form (SF) for WAIS-IV in a sample of adults with schizophrenia (SZ) and schizoaffective disorder. Seventy patients diagnosed with schizophrenia or schizoaffective disorder were administered the full version of the WAIS-IV. Four different versions of the Ward's SF were then calculated. The subtests used were: Similarities, Digit Span, Arithmetic, Information, Coding, Picture Completion, and Block Design (BD version) or Matrix Reasoning (MR version). Prorated and regression-based formulae were assessed for each version. The actual and estimated factorial indexes reflected the typical pattern observed in schizophrenia. The four SFs correlated significantly with their full-version counterparts, but the Perceptual Reasoning Index (PRI) correlated below the acceptance threshold for all four versions. The regression-derived estimates showed larger differences compared to the full form. The four forms revealed comparable but generally low clinical category agreement rates for factor indexes. All SFs showed an acceptable reliability, but they were not correlated with clinical outcomes. The WAIS-IV SF offers a good estimate of WAIS-IV intelligence quotient, which is consistent with previous results. Although the overall scores are comparable between the four versions, the prorated forms provided a better estimation of almost all indexes. MR can be used as an alternative for BD without substantially changing the psychometric properties of the SF. However, we recommend a cautious use of these abbreviated forms when it is necessary to estimate the factor index scores, especially PRI, and Processing Speed Index. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Discrepancy Score Reliabilities in the WAIS-IV Standardization Sample

    ERIC Educational Resources Information Center

    Glass, Laura A.; Ryan, Joseph J.; Charter, Richard A.

    2010-01-01

    In the present investigation, the authors provide internal consistency reliabilities for Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) subtest and Index discrepancy scores using the standardization sample as the data source. Reliabilities ranged from 0.55 to 0.88 for subtest discrepancy scores and 0.80 to 0.91 for Index discrepancy…

  14. Effects of conversion of mangroves into gei wai ponds on sediment heavy metals accumulation in tidal flat estuary, South China

    NASA Astrophysics Data System (ADS)

    Li, R.; Qiu, G.; Chai, M.; Li, R.

    2017-12-01

    Gei wai ponds act as important component in mangrove ecosystem, but the conversion of mangroves into gei wai ponds and its ecological function on heavy metal accumulation is still not clear. The study quantified the sediment heavy metal concentration and speciation in gei wai pond, Avicennia marina marsh and mudflat in Futian mangrove wetlands, South China. The results showed that gei wai pond acidified the sediment and reduced its fertility due to reduced pH, electronic conductivity (EC) and total organic carbon (TOC) compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all depth in gei wai pond sediment were also lower than other sites, indicating reduced storage function on heavy metals. Multiple analysis implied that heavy metals in all sites could be attributed to anthropogenic sources, with Cr as natural and anthropogenic sources in gei wai pond. Gei wai pond sediment had lower heavy metal pollution based on multiple evaluation methods, including potential ecological risk coefficient (Eir), potential ecological risk index (RI), geo-accumulation index (Igeo), mean PEL quotients (m-PEL-q), pollution load index (PLI), mean ERM quotients (m-ERM-q) and total toxic unit (∑TU). Heavy metal speciation analysis indicated that gei wai pond improved the conversion from the immobilized Cd and Cr to the mobilized fraction. SEM-AVS analysis indicated no adverse toxicity occurred in all sites, and the role of TOC in relieving sediment heavy metal toxicity of gei wai pond is limited.

  15. Effects of conversion of mangroves into gei wai ponds on accumulation, speciation and risk of heavy metals in intertidal sediments.

    PubMed

    Li, Rongyu; Qiu, Guo Yu; Chai, Minwei; Shen, Xiaoxue; Zan, Qijie

    2018-06-23

    Mangroves are often converted into gei wai ponds for aquaculture, but how such conversion affects the accumulation and behavior of heavy metals in sediments is not clear. The present study aims to quantify the concentration and speciation of heavy metals in sediments in different habitats, including gei wai pond, mangrove marsh dominated by Avicennia marina and bare mudflat, in a mangrove nature reserve in South China. The results showed that gei wai pond acidified the sediment and reduced its electronic conductivity and total organic carbon (TOC) when compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all sediment depths in gei wai pond were lower than the other habitats, indicating gei wai pond reduced the fertility and the ability to retain heavy metals in sediment. Gei wai pond sediment also had a lower heavy metal pollution problem according to multiple evaluation methods, including potential ecological risk coefficient, potential ecological risk index, geo-accumulation index, mean PEL quotients, pollution load index, mean ERM quotients and total toxic unit. Heavy metal speciation analysis showed that gei wai pond increased the transfer of the immobilized fraction of Cd and Cr to the mobilized one. According to the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) analysis, the conversion of mangroves into gei wai pond reduced values of ([SEM] - [AVS])/f oc , and the role of TOC in alleviating heavy metal toxicity in sediment. This study demonstrated the conversion of mangrove marsh into gei wai pond not only reduced the ecological purification capacity on heavy metal contamination, but also enhanced the transfer of heavy metals from gei wai pond sediment to nearby habitats.

  16. Neuropsychological Profiles on the WAIS-IV of Adults With ADHD.

    PubMed

    Theiling, Johanna; Petermann, Franz

    2016-11-01

    The aim of the study was to investigate the pattern of neuropsychological profiles on the Wechsler Adult Intelligence Scale-IV (WAIS-IV) for adults With ADHD relative to randomly matched controls and to assess overall intellectual ability discrepancies of the Full Scale Intelligence Quotient (FSIQ) and the General Ability Index (GAI). In all, 116 adults With ADHD and 116 controls between 16 and 71 years were assessed. Relative to controls, adults With ADHD show significant decrements in subtests with working memory and processing speed demands with moderate to large effect sizes and a higher GAI in comparison with the FSIQ. This suggests first that deficits identified with previous WAIS versions are robust in adults With ADHD and remain deficient when assessed with the WAIS-IV; second that the WAIS-IV reliably differentiates between patients and controls; and third that a reduction of the FSIQ is most likely due to a decrement in working memory and processing speed abilities. The findings have essential implications for the diagnostic process. © The Author(s) 2014.

  17. An empirical comparative study on biological age estimation algorithms with an application of Work Ability Index (WAI).

    PubMed

    Cho, Il Haeng; Park, Kyung S; Lim, Chang Joo

    2010-02-01

    In this study, we described the characteristics of five different biological age (BA) estimation algorithms, including (i) multiple linear regression, (ii) principal component analysis, and somewhat unique methods developed by (iii) Hochschild, (iv) Klemera and Doubal, and (v) a variant of Klemera and Doubal's method. The objective of this study is to find the most appropriate method of BA estimation by examining the association between Work Ability Index (WAI) and the differences of each algorithm's estimates from chronological age (CA). The WAI was found to be a measure that reflects an individual's current health status rather than the deterioration caused by a serious dependency with the age. Experiments were conducted on 200 Korean male participants using a BA estimation system developed principally under the concept of non-invasive, simple to operate and human function-based. Using the empirical data, BA estimation as well as various analyses including correlation analysis and discriminant function analysis was performed. As a result, it had been confirmed by the empirical data that Klemera and Doubal's method with uncorrelated variables from principal component analysis produces relatively reliable and acceptable BA estimates. 2009 Elsevier Ireland Ltd. All rights reserved.

  18. Health check documentation of psychosocial factors using the WAI.

    PubMed

    Uronen, L; Heimonen, J; Puukka, P; Martimo, K-P; Hartiala, J; Salanterä, S

    2017-03-01

    Health checks in occupational health (OH) care should prevent deterioration of work ability and promote well-being at work. Documentation of health checks should reflect and support continuity of prevention and practice. To analyse how OH nurses (OHNs) undertaking health checks document psychosocial factors at work and use the Work Ability Index (WAI). Analysis of two consecutive OHN health check records and WAI scores with statistical analyses and annotations of 13 psychosocial factors based on a publicly available standard on psychosocial risk management: British Standards Institution specification PAS 1010, part of European Council Directive 89/391/EEC, with a special focus on work-related stress and workplace violence. We analysed health check records for 196 employees. The most frequently documented psychosocial risk factors were home-work interface, work environment and equipment, job content, workload and work pace and work schedule. The correlations between the number of documented risk and non-risk factors and WAI scores were significant: OHNs documented more risk factors in employees with lower WAI scores. However, documented psychosocial risk factors were not followed up, and the OHNs' most common response to detected psychosocial risks was an appointment with a physician. The number of psychosocial risk factors documented by OHNs correlated with subjects' WAI scores. However, the documentation was not systematic and the interventions were not always relevant. OHNs need a structure to document psychosocial factors and more guidance in how to use the documentation as a tool in their decision making in health checks. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  19. Help Is on the WAIS.

    ERIC Educational Resources Information Center

    Lukanuski, Mary

    1992-01-01

    Describes the development of the WAIS (Wide Area Information Servers) protocol, a system that allows users access to personal, corporate, and commercial electronic information from one interface. The availability of WAIS on the Internet and the reactions of users are addressed. Several problems are considered, including funding, hardware…

  20. WAIS Searching of the Current Contents Database

    NASA Astrophysics Data System (ADS)

    Banholzer, P.; Grabenstein, M. E.

    The Homer E. Newell Memorial Library of NASA's Goddard Space Flight Center is developing capabilities to permit Goddard personnel to access electronic resources of the Library via the Internet. The Library's support services contractor, Maxima Corporation, and their subcontractor, SANAD Support Technologies have recently developed a World Wide Web Home Page (http://www-library.gsfc.nasa.gov) to provide the primary means of access. The first searchable database to be made available through the HomePage to Goddard employees is Current Contents, from the Institute for Scientific Information (ISI). The initial implementation includes coverage of articles from the last few months of 1992 to present. These records are augmented with abstracts and references, and often are more robust than equivalent records in bibliographic databases that currently serve the astronomical community. Maxima/SANAD selected Wais Incorporated's WAIS product with which to build the interface to Current Contents. This system allows access from Macintosh, IBM PC, and Unix hosts, which is an important feature for Goddard's multiplatform environment. The forms interface is structured to allow both fielded (author, article title, journal name, id number, keyword, subject term, and citation) and unfielded WAIS searches. The system allows a user to: Retrieve individual journal article records. Retrieve Table of Contents of specific issues of journals. Connect to articles with similar subject terms or keywords. Connect to other issues of the same journal in the same year. Browse journal issues from an alphabetical list of indexed journal names.

  1. Structural validity of the Dutch-language version of the WAIS-III in a psychiatric sample.

    PubMed

    van der Heijden, Paul; van den Bos, Pancras; Mol, Bart; Kessels, Roy P C

    2013-01-01

    The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008 ) no longer provides the "traditional" Verbal IQ and Performance IQ deviation scores. In the current study, we investigated the structural validity of these scores in the scale's predecessor, the WAIS-Third Edition (WAIS-III; Wechsler, 1997c ), which is still widely used in clinical practice, especially outside the United States. Confirmative (CFA) and exploratory factor analyses (EFA) were performed on WAIS-III data from a Dutch sample of 247 psychiatric patients. Four competing models were tested in the CFA on 11 subtests. The model that fit the data best was a model in which subtests loaded on the four factor indexes (i.e., 3 Verbal Comprehension subtests, 3 Perceptual Organization subtests, 3 Working Memory subtests, and 2 Processing Speed subtests) as proposed by the manual (Wechsler, 1997b ). In the EFA on 13 subtests with four factors extracted, all subtests were found to load on the factors in accordance with the WAIS-III test manual. However, Picture Arrangement, Arithmetic, and Picture Completion showed only moderate loadings on the proposed factors. Implications for clinical practice are discussed.

  2. Orthogonal higher order structure and confirmatory factor analysis of the French Wechsler Adult Intelligence Scale (WAIS-III).

    PubMed

    Golay, Philippe; Lecerf, Thierry

    2011-03-01

    According to the most widely accepted Cattell-Horn-Carroll (CHC) model of intelligence measurement, each subtest score of the Wechsler Intelligence Scale for Adults (3rd ed.; WAIS-III) should reflect both 1st- and 2nd-order factors (i.e., 4 or 5 broad abilities and 1 general factor). To disentangle the contribution of each factor, we applied a Schmid-Leiman orthogonalization transformation (SLT) to the standardization data published in the French technical manual for the WAIS-III. Results showed that the general factor accounted for 63% of the common variance and that the specific contributions of the 1st-order factors were weak (4.7%-15.9%). We also addressed this issue by using confirmatory factor analysis. Results indicated that the bifactor model (with 1st-order group and general factors) better fit the data than did the traditional higher order structure. Models based on the CHC framework were also tested. Results indicated that a higher order CHC model showed a better fit than did the classical 4-factor model; however, the WAIS bifactor structure was the most adequate. We recommend that users do not discount the Full Scale IQ when interpreting the index scores of the WAIS-III because the general factor accounts for the bulk of the common variance in the French WAIS-III. The 4 index scores cannot be considered to reflect only broad ability because they include a strong contribution of the general factor.

  3. Independent Examination of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV): What Does the WAIS-IV Measure?

    ERIC Educational Resources Information Center

    Benson, Nicholas; Hulac, David M.; Kranzler, John H.

    2010-01-01

    Published empirical evidence for the Wechsler Adult Intelligence Scale--Fourth Edition (WAIS-IV) does not address some essential questions pertaining to the applied practice of intellectual assessment. In this study, the structure and cross-age invariance of the latest WAIS-IV revision were examined to (a) elucidate the nature of the constructs…

  4. Math anxiety differentially affects WAIS-IV arithmetic performance in undergraduates.

    PubMed

    Buelow, Melissa T; Frakey, Laura L

    2013-06-01

    Previous research has shown that math anxiety can influence the math performance level; however, to date, it is unknown whether math anxiety influences performance on working memory tasks during neuropsychological evaluation. In the present study, 172 undergraduate students completed measures of math achievement (the Math Computation subtest from the Wide Range Achievement Test-IV), math anxiety (the Math Anxiety Rating Scale-Revised), general test anxiety (from the Adult Manifest Anxiety Scale-College version), and the three Working Memory Index tasks from the Wechsler Adult Intelligence Scale-IV Edition (WAIS-IV; Digit Span [DS], Arithmetic, Letter-Number Sequencing [LNS]). Results indicated that math anxiety predicted performance on Arithmetic, but not DS or LNS, above and beyond the effects of gender, general test anxiety, and math performance level. Our findings suggest that math anxiety can negatively influence WAIS-IV working memory subtest scores. Implications for clinical practice include the utilization of LNS in individuals expressing high math anxiety.

  5. An examination of the Wechsler Adult Intelligence Scales, Fourth Edition (WAIS-IV) in individuals with complicated mild, moderate and Severe traumatic brain injury (TBI).

    PubMed

    Carlozzi, Noelle E; Kirsch, Ned L; Kisala, Pamela A; Tulsky, David S

    2015-01-01

    This study examined the clinical utility of the Wechsler Adult Intelligence Scales-Fourth Edition (WAIS-IV) in individuals with complicated mild, moderate or severe TBI. One hundred individuals with TBI (n = 35 complicated mild or moderate TBI; n = 65 severe TBI) and 100 control participants matched on key demographic variables from the WAIS-IV normative dataset completed the WAIS-IV. Univariate analyses indicated that participants with severe TBI had poorer performance than matched controls on all index scores and subtests (except Matrix Reasoning). Individuals with complicated mild/moderate TBI performed more poorly than controls on the Working Memory Index (WMI), Processing Speed Index (PSI), and Full Scale IQ (FSIQ), and on four subtests: the two processing speed subtests (SS, CD), two working memory subtests (AR, LN), and a perceptual reasoning subtest (BD). Participants with severe TBI had significantly lower scores than the complicated mild/moderate TBI on PSI, and on three subtests: the two processing speed subtests (SS and CD), and the new visual puzzles test. Effect sizes for index and subtest scores were generally small-to-moderate for the group with complicated mild/moderate and moderate-to-large for the group with severe TBI. PSI also showed good sensitivity and specificity for classifying individuals with severe TBI versus controls. Findings provide support for the clinical utility of the WAIS-IV in individuals with complicated mild, moderate, and severe TBI.

  6. Application of new WAIS-III/WMS-III discrepancy scores for evaluating memory functioning: relationship between intellectual and memory ability.

    PubMed

    Lange, Rael T; Chelune, Gordon J

    2006-05-01

    Analysis of the discrepancy between memory and intellectual ability has received some support as a means for evaluating memory impairment. Recently, comprehensive base rate tables for General Ability Index (GAI) minus memory discrepancy scores (i.e., GAI-memory) were developed using the WAIS-III/WMS-III standardization sample (Lange, Chelune, & Tulsky, in press). The purpose of this study was to evaluate the clinical utility of GAI-memory discrepancy scores to identify memory impairment in 34 patients with Alzheimer's type dementia (DAT) versus a sample of 34 demographically matched healthy participants. On average, patients with DAT obtained significantly lower scores on all WAIS-III and WMS-III indexes and had larger GAI-memory discrepancy scores. Clinical outcome analyses revealed that GAI-memory scores were useful at identifying memory impairment in patients with DAT versus matched healthy participants. However, GAI-memory discrepancy scores failed to provide unique interpretive information beyond that which is gained from the memory indexes alone. Implications and future research directions are discussed.

  7. A Comparison of the Interest Accuracy of Two Short Forms of the WAIS-R.

    ERIC Educational Resources Information Center

    Cella, David F.; And Others

    1985-01-01

    Examined relative efficacy of two short forms of Wechsler Adult Intelligence Scale-Revised (WAIS-R) with respect to accurate subtest profile scatter (N=50). Subtest scores of both split-half Satz-Mogel short form and criterion referenced Modified WAIS-R (WAIS-RM) short form were found to differ significantly from full-length WAIS-R subtest scores.…

  8. Working alliance inventory applied to virtual and augmented reality (WAI-VAR): psychometrics and therapeutic outcomes

    PubMed Central

    Miragall, Marta; Baños, Rosa M.; Cebolla, Ausiàs; Botella, Cristina

    2015-01-01

    This study examines the psychometric properties of the Working Alliance Inventory-Short (WAI-S) adaptation to Virtual Reality (VR) and Augmented Reality (AR) therapies (WAI-VAR). The relationship between the therapeutic alliance (TA) with VR and AR and clinically significant change (CSC) is also explored. Seventy-five patients took part in this study (74.7% women, Mage = 34.41). Fear of flying and adjustment disorder patients received VR therapy, and cockroach phobia patients received AR therapy. Psychometric properties, CSC, one-way ANOVA, Spearman’s Correlations and Multiple Regression were calculated. The WAI-VAR showed a unidimensional structure, high internal consistency and adequate convergent validity. “Not changed” patients scored lower on the WAI-VAR than “improved” and “recovered” patients. Correlation between the WAI-VAR and CSC was moderate. The best fitting model for predicting CSC was a linear combination of the TA with therapist (WAI-S) and the TA with VR and AR (WAI-VAR), due to the latter variable slightly increased the percentage of variability accounted for in CSC. The WAI-VAR is the first validated instrument to measure the TA with VR and AR in research and clinical practice. This study reveals the importance of the quality of the TA with technologies in achieving positive outcomes in the therapy. PMID:26500589

  9. Working alliance inventory applied to virtual and augmented reality (WAI-VAR): psychometrics and therapeutic outcomes.

    PubMed

    Miragall, Marta; Baños, Rosa M; Cebolla, Ausiàs; Botella, Cristina

    2015-01-01

    This study examines the psychometric properties of the Working Alliance Inventory-Short (WAI-S) adaptation to Virtual Reality (VR) and Augmented Reality (AR) therapies (WAI-VAR). The relationship between the therapeutic alliance (TA) with VR and AR and clinically significant change (CSC) is also explored. Seventy-five patients took part in this study (74.7% women, M age = 34.41). Fear of flying and adjustment disorder patients received VR therapy, and cockroach phobia patients received AR therapy. Psychometric properties, CSC, one-way ANOVA, Spearman's Correlations and Multiple Regression were calculated. The WAI-VAR showed a unidimensional structure, high internal consistency and adequate convergent validity. "Not changed" patients scored lower on the WAI-VAR than "improved" and "recovered" patients. Correlation between the WAI-VAR and CSC was moderate. The best fitting model for predicting CSC was a linear combination of the TA with therapist (WAI-S) and the TA with VR and AR (WAI-VAR), due to the latter variable slightly increased the percentage of variability accounted for in CSC. The WAI-VAR is the first validated instrument to measure the TA with VR and AR in research and clinical practice. This study reveals the importance of the quality of the TA with technologies in achieving positive outcomes in the therapy.

  10. Multidimensional Relationships in the WAIS-R Subscales and Demographic Variables.

    ERIC Educational Resources Information Center

    Chastain, Robert L.; Joe, George W.

    This study attempts to integrate and extend previous research by multivariate investigation to determine multidimensional relationships among both the Wechsler Adult Intelligence Scale-Revised (WAIS-R) subscales and the demographic variables for the 1981 WAIS-R standardization sample. Canonical correlation with orthogonal rotation of composite…

  11. Graduate Student WAIS-III Scoring Accuracy Is a Function of Full Scale IQ and Complexity of Examiner Tasks

    ERIC Educational Resources Information Center

    Hopwood, Christopher J.; Richard, David C. S.

    2005-01-01

    Research on the Wechsler Adult Intelligence Scale-Revised and Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) suggests that practicing clinical psychologists and graduate students make item-level scoring errors that affect IQ, index, and subtest scores. Studies have been limited in that Full-Scale IQ (FSIQ) and examiner administration,…

  12. A Study on Work Ability Index and Physical Work Capacity on the Base of Fax Equation VO(2) Max in Male Nursing Hospital Staff in Isfahan, Iran.

    PubMed

    Habibi, Ehsanollah; Dehghan, Habibollah; Zeinodini, Mohhamad; Yousefi, Hosseinali; Hasanzadeh, Akbar

    2012-11-01

    The purpose of this research is to establish the ability of employees by work ability index (WAI), physical work capacity (PWC), and finding the correlation between them. Establishing the PWC index with attention to WAI values for the purpose of saving in costs and time of PWC measurements is another aim of this project. The present research is an analytic cross-sectional and one-trail study. The study population consists of 228 randomly selected registered nurses from hospitals in Isfahan (Iran). The WAI and PWC were established through WAI questionnaire and Fax equation and by using ergometer bicycle, respectively. The resulting data were analyzed using SPSS 16 software. Average WAI and PWC among the study population were 38.25±4.4 and 4.45±0.7, respectively. Pearson test results showed no significant correlation between PWC and WAI in different age groups (r=0.3 and P>0.05). Multiple linear regression analysis showed that the variables of age and diagnosed diseases were the most effective factors of WAI (β=0.18 and P>0.05). Pearson test revealed a significant correlation between the number of diagnosed diseases and PWC index in age groups of 40-49 years. Average WAI in this research, like other studies on similar jobs is in the acceptable level of >36. Work ability index and PWC index in different age groups did not show a significant correlation and this suggests that there are essential discrepancies in work ability evaluations made by each index and it is not possible to predict PWC index using WAI values. Given the PWC results and the level of nursing staff's activity (low, medium) the WAI is a suitable instrument to establish the professionals' abilities. This study revealed that 27.6% of individuals were subject to medium-low work ability risk (WAI<37), which was 1.8 times that of Finland's professional health Institute, which could be caused by shift working and increased working hours.

  13. Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry

    DOEpatents

    Yeung, E.S.; Woodruff, S.D.

    1984-06-19

    A refractive index and absorption detector are disclosed for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded. 10 figs.

  14. Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry

    DOEpatents

    Yeung, Edward S.; Woodruff, Steven D.

    1984-06-19

    A refractive index and absorption detector for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded.

  15. Low-refractive-index dye-aggregate films with small absorption based on anomalous dispersion.

    PubMed

    Wakamatsu, Takashi; Watanabe, Keita; Saito, Kazuhiro

    2005-02-20

    Complex-refractive-index spectra of Squarylium (SQ) dye-aggregate films deposited upon metal films have been investigated by measurements of properties of the films including absorption spectra (AS) and attenuated total reflection. Complex refractive indices are estimated by Kramers-Kronig analysis for the AS and by a theoretical curve-fitting analysis for attenuated total reflection. The dye-aggregate films exhibited an absorption that was blueshifted from that of a monomer, as a result of the H-aggregate formation of SQ molecules, and had a changing refractive index with anomalous dispersion about the H-absorption band. From both measurements of the SQ films it was found that there is a region of low absorption in the short-wavelength side of the absorption band and that the refractive index there is lower than that of glass.

  16. Low-refractive-index dye-aggregate films with small absorption based on anomalous dispersion

    NASA Astrophysics Data System (ADS)

    Wakamatsu, Takashi; Watanabe, Keita; Saito, Kazuhiro

    2005-02-01

    Complex-refractive-index spectra of Squarylium (SQ) dye-aggregate films deposited upon metal films have been investigated by measurements of properties of the films including absorption spectra (AS) and attenuated total reflection. Complex refractive indices are estimated by Kramers-Kronig analysis for the AS and by a theoretical curve-fitting analysis for attenuated total reflection. The dye-aggregate films exhibited an absorption that was blueshifted from that of a monomer, as a result of the H-aggregate formation of SQ molecules, and had a changing refractive index with anomalous dispersion about the H-absorption band. From both measurements of the SQ films it was found that there is a region of low absorption in the short-wavelength side of the absorption band and that the refractive index there is lower than that of glass.

  17. WAIS-IV subtest covariance structure: conceptual and statistical considerations.

    PubMed

    Ward, L Charles; Bergman, Maria A; Hebert, Katina R

    2012-06-01

    D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning, and Processing Speed) but also revealed unexplained covariance between Block Design and Visual Puzzles (Perceptual Reasoning subtests). That covariance was not included in the final models. Instead, a path was added from Working Memory to Figure Weights (Perceptual Reasoning subtest) to improve fit and achieve a desired factor pattern. The present research with the same data (N = 1,800) showed that the path from Working Memory to Figure Weights increases the association between Working Memory and Matrix Reasoning. Specifying both paths improves model fit and largely eliminates unexplained covariance between Block Design and Visual Puzzles but with the undesirable consequence that Figure Weights and Matrix Reasoning are equally determined by Perceptual Reasoning and Working Memory. An alternative 4-factor model was proposed that explained theory-implied covariance between Block Design and Visual Puzzles and between Arithmetic and Figure Weights while maintaining compatibility with WAIS-IV Index structure. The proposed model compared favorably with a 5-factor model based on Cattell-Horn-Carroll theory. The present findings emphasize that covariance model comparisons should involve considerations of conceptual coherence and theoretical adherence in addition to statistical fit. (c) 2012 APA, all rights reserved

  18. Test Review: Advanced Clinical Solutions for WAIS-IV and WMS-IV

    ERIC Educational Resources Information Center

    Chu, Yiting; Lai, Mark H. C.; Xu, Yining; Zhou, Yuanyuan

    2012-01-01

    The authors review the "Advanced Clinical Solutions for WAIS-IV and WMS-IV". The "Advanced Clinical Solutions (ACS) for the Wechsler Adult Intelligence Scale-Fourth Edition" (WAIS-IV; Wechsler, 2008) and the "Wechsler Memory Scale-Fourth Edition" (WMS-IV; Wechsler, 2009) was published by Pearson in 2009. It is a…

  19. A comparison of Boolean-based retrieval to the WAIS system for retrieval of aeronautical information

    NASA Technical Reports Server (NTRS)

    Marchionini, Gary; Barlow, Diane

    1994-01-01

    An evaluation of an information retrieval system using a Boolean-based retrieval engine and inverted file architecture and WAIS, which uses a vector-based engine, was conducted. Four research questions in aeronautical engineering were used to retrieve sets of citations from the NASA Aerospace Database which was mounted on a WAIS server and available through Dialog File 108 which served as the Boolean-based system (BBS). High recall and high precision searches were done in the BBS and terse and verbose queries were used in the WAIS condition. Precision values for the WAIS searches were consistently above the precision values for high recall BBS searches and consistently below the precision values for high precision BBS searches. Terse WAIS queries gave somewhat better precision performance than verbose WAIS queries. In every case, a small number of relevant documents retrieved by one system were not retrieved by the other, indicating the incomplete nature of the results from either retrieval system. Relevant documents in the WAIS searches were found to be randomly distributed in the retrieved sets rather than distributed by ranks. Advantages and limitations of both types of systems are discussed.

  20. Concurrent Validity of Wechsler Adult Intelligence Scales-Third Edition Index Score Short Forms in the Canadian Standardization Sample

    ERIC Educational Resources Information Center

    Lange, Rael T.; Iverson, Grant L.

    2008-01-01

    This study evaluated the concurrent validity of estimated Wechsler Adult Intelligence Scales-Third Edition (WAIS-III) index scores using various one- and two-subtest combinations. Participants were the Canadian WAIS-III standardization sample. Using all possible one- and two-subtest combinations, an estimated Verbal Comprehension Index (VCI), an…

  1. Similarity of WISC-R and WAIS-R Scores at Age 16.

    ERIC Educational Resources Information Center

    Sandoval, Jonathan; And Others

    1988-01-01

    Examined similarity of scores of 30 learning disabled students (aged 16 and 17) on the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Results documented similarity between WISC-R and WAIS-R for 16 year-olds who were learning disabled and had average intellectual ability.…

  2. WAIS-III FSIQ and GAI in ability-memory discrepancy analysis.

    PubMed

    Glass, Laura A; Bartels, Jared M; Ryan, Joseph J

    2009-01-01

    The present investigation compares WAIS-III FSIQ-WMS-III with GAI-WMS-III discrepancies in 135 male inpatients with suspected memory impairment. Full Scale IQ and GAI scores were highly correlated, r= .96, with mean values of 92.10 and 93.59, respectively. Additional analyses with the ability composites compared to each WMS-III index (IMI, GMI, and DMI), the GAI consistently produced larger difference scores than did the FSIQ; however, effect sizes were relatively small (ES= .12). Lastly, case-by-case analyses demonstrated concordance rates of 86% for the FSIQ-IMI and GAI-IMI comparisons, 85% for the FSIQ-GMI and GAI-GMI, and 82% for the FSIQ-DMI and GAI-DMI.

  3. Cognitive profiles of adults with high-functioning autism spectrum disorder and those with attention-deficit/hyperactivity disorder based on the WAIS-III.

    PubMed

    Kanai, Chieko; Hashimoto, Ryuichiro; Itahashi, Takashi; Tani, Masayuki; Yamada, Takashi; Ota, Haruhisa; Iwanami, Akira; Kato, Nobumasa

    2017-02-01

    The cognitive profile differences between adult patients with autism spectrum disorder (ASD) and those with attention-deficit/hyperactivity disorder (ADHD) are not well characterized. We examined the cognitive profiles of adults having either ASD (n=120) or ADHD (n=76) with no intellectual disabilities (IQ≥70) using the Wechsler Intelligence Scale III (WAIS-III). Verbal Intelligence (VIQ) - Performance Intelligence (PIQ) difference discrepancies were detected between the two groups. Information subtest scores of the Verbal Comprehension index and Arithmetic and Digit Span subtests of the Freedom from Distractibility index were significantly higher in ASD than in ADHD, while the Picture Completion subtest was significantly lower in ASD. To our knowledge, this is the first study to evaluate the difference in the cognitive profiles of adults with ASD and those with ADHD based on the WAIS III with a large number of participants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The First Annual West Antarctic Ice Sheet (WAIS) Science Workshop

    NASA Technical Reports Server (NTRS)

    Bindschadler, Robert A. (Editor)

    1993-01-01

    A compilation of abstracts presented at the workshop are presented. The goal was to answer the question, what is the future behavior and potential for rapid collapse of the West Antarctic Ice Sheet (WAIS)? The workshop was organized into four sessions corresponding to the four objectives identified as necessary to reach the WAIS workshop goal: history, current behavior, internal dynamics, and environmental interactions. Presentations were organized by their relevance to each objective, rather than by discipline.

  5. The Prognostic Value of the Work Ability Index for Sickness Absence among Office Workers.

    PubMed

    Reeuwijk, Kerstin G; Robroek, Suzan J W; Niessen, Maurice A J; Kraaijenhagen, Roderik A; Vergouwe, Yvonne; Burdorf, Alex

    2015-01-01

    The work ability index (WAI) is a frequently used tool in occupational health to identify workers at risk for a reduced work performance and for work-related disability. However, information about the prognostic value of the WAI to identify workers at risk for sickness absence is scarce. To investigate the prognostic value of the WAI for sickness absence, and whether the discriminative ability differs across demographic subgroups. At baseline, the WAI (score 7-49) was assessed among 1,331 office workers from a Dutch financial service company. Sickness absence was registered during 12-months follow-up and categorised as 0 days, 0WAI and sickness absence were estimated by multinomial regression analyses. Discriminative ability of the WAI was assessed by the Area Under the Curve (AUC) and Ordinal c-index (ORC). Test characteristics were determined for dichotomised outcomes. Additional analyses were performed for separate WAI dimensions, and subgroup analyses for demographic groups. A lower WAI was associated with sickness absence (≥15 days vs. 0 days: per point lower WAI score OR=1.27; 95%CI 1.21-1.33). The WAI showed reasonable ability to discriminate between categories of sickness absence (ORC=0.65; 95%CI 0.63-0.68). Highest discrimination was found for comparing workers with ≥15 sick days with 0 sick days (AUC=0.77) or with 1-5 sick days (AUC=0.69). At the cut-off for poor work ability (WAI≤27) the sensitivity to identify workers at risk for ≥15 sick days was 7.5%, the specificity 99.6%, and the positive predictive value 82%. The performance was similar across demographic subgroups. The WAI could be used to identify workers at high risk for prolonged sickness absence. However, due to low sensitivity many workers will be missed. Hence, additional factors are required to better identify workers at highest risk.

  6. Age-related commonalities and differences in the relationship between executive functions and intelligence: Analysis of the NAB executive functions module and WAIS-IV scores.

    PubMed

    Buczylowska, Dorota; Petermann, Franz

    2017-01-01

    Data from five subtests of the Executive Functions Module of the German Neuropsychological Assessment Battery (NAB) and all ten core subtests of the German Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV) were used to examine the relationship between executive functions and intelligence in a comparison of two age groups: individuals aged 18-59 years and individuals aged 60-88 years. The NAB subtests Categories and Word Generation demonstrated a consistent correlation pattern for both age groups. However, the NAB Judgment subtest correlated more strongly with three WAIS-IV indices, the Full Scale IQ (FSIQ), and the General Ability Index (GAI) in the older adult group than in the younger group. Additionally, in the 60-88 age group, the Executive Functions Index (EFI) was more strongly correlated with the Verbal Comprehension Index (VCI) than with the Perceptual Reasoning Index (PRI). Both age groups demonstrated a strong association of the EFI with the FSIQ and the Working Memory Index (WMI). The results imply the potential diagnostic utility of the Judgment subtest and a significant relationship between executive functioning and crystallized intelligence at older ages. Furthermore, it may be concluded that there is a considerable age-independent overlap between the EFI and general intelligence, as well as between the EFI and working memory.

  7. Relationship between Work Ability Index and Cognitive Failure among Nurses.

    PubMed

    Abbasi, Milad; Zakerian, Abolfazl; Kolahdouzi, Malihe; Mehri, Ahmad; Akbarzadeh, Arash; Ebrahimi, Mohammad Hossein

    2016-03-01

    Frequent nursing errors are considered as factors that affect the quality of healthcare of patients. Capable nurses who are compatible with work conditions are more focused on their tasks, and this reduces their errors and cognitive failures. Therefore, this study was conducted with the aim of investigating the relationship between work ability index (WAI) and cognitive failures (CFs) as well as some factors that affect them in nurses working in the ICU, CCU, and emergency wards. This descriptive-analytical and cross-sectional study was conducted with 750 nurses at educational hospitals affiliated with the Tehran University of Medical Sciences in 2015. A questionnaire of work ability index and cognitive failures was used to collect data. The data were analyzed using SPSS 20 and the Pearson and Spearman correlation coefficients, chi-squared, ANOVA, and the Kruskal-Wallis tests. Using the Pearson correlation test, the results of this study showed that there is a significant, inverse relationship between WAI, personal prognosis of work ability, and mental resources with CFs along with all its subscales in nurses (p < 0.05). In addition, there was an inverse and significant relationship between the total score of CFs and the estimated work impairment due to diseases (p < 0.05). There was a significant positive correlation of CFs with age and experience, while WAI was inversely related to age, work experience, and body mass index (BMI) (p < 0.05). WAI and CFs were related significantly to working units (p < 0.05). Considering the results obtained in this study, WAI and the cognitive status of nurses were lower than the specified limit. It is suggested that the work ability of nurses be improved and that their CFs be reduced through various measures, including pre-employment examinations, proper management of work-shift conditions, and using engineering and administrative strategies to ensure the safety of hospitalized patients.

  8. WAIS-IV and Clinical Validation of the Four- and Five-Factor Interpretative Approaches

    ERIC Educational Resources Information Center

    Weiss, Lawrence G.; Keith, Timothy Z.; Zhu, Jianjun; Chen, Hsinyi

    2013-01-01

    The fourth edition of the Wechsler Adult Intelligence Scale (WAIS-IV) is a revised and substantially updated version of its predecessor. The purposes of this research were to determine the constructs measured by the test and the consistency of measurement across large normative and clinical samples. Competing higher order WAIS-IV four- and…

  9. Simultaneous measurements of absorption spectrum and refractive index in a microfluidic system.

    PubMed

    Helseth, Lars Egil

    2012-02-13

    The characterization of dyes in various solvents requires determination of the absorption spectrum of the dye as well as the refractive index of the solvent. Typically, the refractive index of the solvent and the absorption spectrum of the solute are measured using separate experimental setups where significant liquid volumes are required. In this work the first optical measurement system that is able to do simultaneous measurements of the refractive index of the solvent and the spectral properties of the solute in a microscopic volume is presented. The laser dye Rhodamine 6G in glycerol is investigated, and the refractive index of the solution is monitored using the interference pattern of the light scattered off the channel, while its spectral properties is found by monitoring reflected light from the channel.

  10. Effects of Work-Related Stress on Work Ability Index among Iranian Workers.

    PubMed

    Gharibi, Vahid; Mokarami, Hamidreza; Taban, Abrahim; Yazdani Aval, Mohsen; Samimi, Kazem; Salesi, Mahmood

    2016-03-01

    Work Ability Index (WAI) is a well-known and valid self-report tool that has been widely used in various studies to identify and avoid early retirement and work-related disability. Nevertheless, very few studies have been carried out to evaluate work ability in Iran. We aimed to investigate the WAI and the effect of work-related stress on it among Iranian workers. A cross-sectional, descriptive and analytic study was carried out among 449 workers from five working sectors in three big cities of Iran. Work ability and work-related stress were measured using the Persian version of WAI and the Persian version of Health and Safety Executive Stress Indicator Tool. More than a third of the workers surveyed (34.70%) did not have an appropriate level of work ability (WAI < 37). There was a significant correlation between subscales of work-related stress and the mean score of WAI. Furthermore, the variables of body mass index, sleep quality, exercise activity, job tenure, and three subscales of work-related stress including demands, supervisor support, and role were significant predictors of WAI. According to the results of this study, the interventional programs must be focused on improving supervisors support, eliminating ambiguity and conflicts in the role of workers in their job and organization, reducing job demands, improving sleep quality, and increasing exercise activity.

  11. Incidental Learning: A Brief, Valid Measure of Memory Based on the WAIS-IV Vocabulary and Similarities Subtests.

    PubMed

    Spencer, Robert J; Reckow, Jaclyn; Drag, Lauren L; Bieliauskas, Linas A

    2016-12-01

    We assessed the validity of a brief incidental learning measure based on the Similarities and Vocabulary subtests of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Most neuropsychological assessments for memory require intentional learning, but incidental learning occurs without explicit instruction. Incidental memory tests such as the WAIS-III Symbol Digit Coding subtest have existed for many years, but few memory studies have used a semantically processed incidental learning model. We conducted a retrospective analysis of 37 veterans with traumatic brain injury, referred for outpatient neuropsychological testing at a Veterans Affairs hospital. As part of their evaluation, the participants completed the incidental learning tasks. We compared their incidental learning performance to their performance on traditional memory measures. Incidental learning scores correlated strongly with scores on the California Verbal Learning Test-Second Edition (CVLT-II) and Brief Visuospatial Memory Test-Revised (BVMT-R). After we conducted a partial correlation that controlled for the effects of age, incidental learning correlated significantly with the CVLT-II Immediate Free Recall, CVLT-II Short-Delay Recall, CVLT-II Long-Delay Recall, and CVLT-II Yes/No Recognition Hits, and with the BVMT-R Delayed Recall and BVMT-R Recognition Discrimination Index. Our incidental learning procedures derived from subtests of the WAIS-IV Edition are an efficient and valid way of measuring memory. These tasks add minimally to testing time and capitalize on the semantic encoding that is inherent in completing the Similarities and Vocabulary subtests.

  12. Are Cross-National Differences in IQ Profiles Stable? A Comparison of Finnish and U.S. WAIS Norms

    ERIC Educational Resources Information Center

    Roivainen, Eka

    2013-01-01

    To study the concept of national IQ profile, we compared U.S. and Finnish WAIS, WAIS-R, and WAIS III nonverbal and working memory subtest norms. The U.S. standardization samples had consistently higher scores on the Coding and Digit span subtests, while the Finnish samples had higher scores on the Block design subtest. No stable cross-national…

  13. Sex and Race Bias in the WAIS-R: A Content and Empirical Analysis.

    ERIC Educational Resources Information Center

    Wrobel, Thomas A.; Howells, Nancy R.

    To examine the issue of item bias within the context of the revised Wechsler Adult Intelligence Scale (WAIS-R), judgments as to perceived item bias were sought. Independent raters nominated 53 WAIS-R items as containing possible bias. White and non-white college students nominated items as racially or sexually biased. Whereas 10 items were judged…

  14. An Investigation of the General Abilities Index in a Group of Diagnostically Mixed Patients

    ERIC Educational Resources Information Center

    Harrison, Allyson G.; DeLisle, Michelle M.; Parker, Kevin C. H.

    2008-01-01

    The General Ability Index (GAI) was compared with Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Full Scale Intelligence Quotient (FSIQ) from the WAIS-III in data obtained from 381 adults assessed for reported learning or attention problems between 1998 and 2005. Not only did clients with more neurocognitively based disorders (i.e.,…

  15. Determination of absorption coefficient of nanofluids with unknown refractive index from reflection and transmission spectra

    NASA Astrophysics Data System (ADS)

    Kim, Joong Bae; Lee, Seungyoon; Lee, Kyungeun; Lee, Ikjin; Lee, Bong Jae

    2018-07-01

    It has been shown that the absorption coefficient of a nanofluid can be actively tuned by changing material, size, shape, and concentration of the nanoparticle suspension. In applications of engineered nanofluids for the direct absorption of solar radiation, it is important to experimentally characterize the absorption coefficient of nanofluids in the solar spectrum. If the refractive index of the base fluid (i.e., the solution without nanoparticles) is known a priori, the absorption coefficient of nanofluids can be easily determined from the transmission spectrum. However, if the refractive index of the base fluid is not known, it is not straightforward to extract the absorption coefficient solely from the transmission spectrum. The present work aims to develop an analytical method of determining the absorption coefficient of nanofluids with unknown refractive index by measuring both reflection and transmission spectra. The proposed method will be validated with deionized water, and the effect of measurement uncertainty will be carefully examined. Finally, the general applicability of the proposed method will also be demonstrated for Therminol VP-1 as well as the Therminol VP-1 - graphite nanofluid.

  16. Long-Term IQ Stability Using the WISC-IV and WAIS-IV among a Sample of Special Education Students

    ERIC Educational Resources Information Center

    Spector, Hayley

    2013-01-01

    The present study investigated the stability of scores on the WISC-IV and WAIS-IV over an approximate six-year period. Previous research using older versions of the WISC and WAIS have suggested that these scales demonstrate strong stability of scores. Since research that has compared the stability of scores between the WISC-IV and the WAIS-IV is…

  17. Personnel's health surveillance at work: effect of age, body mass index, and shift work on mental workload and work ability index.

    PubMed

    Safari, Shahram; Akbari, Jafar; Kazemi, Meghdad; Mououdi, Mohammad Amin; Mahaki, Behzad

    2013-01-01

    Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in textile workers and to identify factors which affect work ability and mental workload. This cross-sectional study was carried out among 194 male workers in textile industry. Employees based on their job group and work conditions have been divided into 6 categories. They completed work ability index and mental workload questionnaires during three work shifts. Body mass index (BMI) and demographic details were recorded. All of the participants rated their work ability as moderate with high mental workload. The mean WAI and mental workload in age group were significant. The mean BMI was 25.5 kg/m(2) (standard deviation 4.1) and the mean age was 40.22 years. There was a statistically significant correlation between work ability index and shift work. Unlike the previous study, a decrease point in WAI started in early age that may be due to life-style work and another psychological factor; on the other hand, NASA-TLX revealed high score in six subscales that can be another reason for low WAI.

  18. WAIS-III IQs, Horn's Theory, and Generational Changes from Young Adulthood to Old Age.

    ERIC Educational Resources Information Center

    Kaufman, Alan S.

    2001-01-01

    Examined age changes in intellectual ability in the range from 16 to 89 years through 2 studies that involved IQs on the Wechsler Adult Intelligence Scale III (WAIS-III). Results are interpreted in the context of the fluid-crystallized intelligence theory of J. Horn. Studies used WAIS-III standardization data for 2,450 adults and longitudinal data…

  19. Transcranial Direct Current Stimulation of Frontal Cortex Decreases Performance on the WAIS-IV Intelligence Test

    PubMed Central

    Sellers, Kristin K.; Mellin, Juliann M.; Lustenberger, Caroline M.; Boyle, Michael R.; Lee, Won Hee; Peterchev, Angel V.; Frohlich, Flavio

    2015-01-01

    Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has tested the effect of tDCS on specific facets of cognition and executive processing. However, no randomized, double-blind, sham-controlled study has looked at the effects of tDCS on a comprehensive battery of cognitive processes. The objective of this study was to test if tDCS had an effect on performance on a comprehensive assay of cognitive processes, a standardized intelligence quotient (IQ) test. The study consisted of two substudies and followed a double-blind, between-subjects, sham-controlled design. In total, 41 healthy adult participants completed the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) as a baseline measure. At least one week later, participants in substudy 1 received either bilateral tDCS (anodes over both F4 and F3, cathode over Cz, 2mA at each anode for 20 minutes) or active sham tDCS (2mA for 40 seconds), and participants in substudy 2 received either right or left tDCS (anode over either F4 or F3, cathode over Cz, 2mA for 20 minutes). In both studies, the WAIS-IV was immediately administered following stimulation to assess for performance differences induced by bilateral and unilateral tDCS. Compared to sham stimulation, right, left, and bilateral tDCS reduced improvement between sessions on Full Scale IQ and the Perceptual Reasoning Index. This demonstration that frontal tDCS selectively degraded improvement on specific metrics of the WAIS-IV raises important questions about the often proposed role of tDCS in cognitive enhancement. PMID:25934490

  20. Specific absorption rate analysis of broadband mobile antenna with negative index metamaterial

    NASA Astrophysics Data System (ADS)

    Alam, Touhidul; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2016-03-01

    This paper presents a negative index metamaterial-inspired printed mobile wireless antenna that can support most mobile applications such as GSM, UMTS, Bluetooth and WLAN frequency bands. The antenna consists of a semi-circular patch, a 50Ω microstrip feed line and metamaterial ground plane. The antenna occupies a very small space of 37 × 47 × 0.508 mm3, making it suitable for mobile wireless application. The perceptible novelty shown in this proposed antenna is that reduction of specific absorption rate using the negative index metamaterial ground plane. The proposed antenna reduced 72.11 and 75.53 % of specific absorption rate at 1.8 and 2.4 GHz, respectively.

  1. Comparison of the WAIS-III and WISC-IV in 16-Year-Old Special Education Students

    ERIC Educational Resources Information Center

    Gordon, Shirley; Duff, Simon; Davidson, Terry; Whitaker, Simon

    2010-01-01

    Background: Previous research with earlier versions of the WISC and WAIS has demonstrated that when administered to people who have intellectual disabilities, the WAIS produced higher IQ scores than the WISC. The aim of this study was to examine whether these differences still exist. A comparison of the Wechsler Adult Intelligence Scale-Third…

  2. Age Dedifferentiation Hypothesis: Evidence form the WAIS III.

    ERIC Educational Resources Information Center

    Juan-Espinosa, Manuel; Garcia, Luis F.; Escorial, Sergio; Rebollo, Irene; Colom, Roberto; Abad, Francisco J.

    2002-01-01

    Used the Spanish standardization of the Wechsler Adult Intelligence Scale III (WAIS III) (n=1,369) to test the age dedifferentiation hypothesis. Results show no changes in the percentage of variance accounted for by "g" and four group factors when restriction of range is controlled. Discusses an age indifferentation hypothesis. (SLD)

  3. Personnel's Health Surveillance at Work: Effect of Age, Body Mass Index, and Shift Work on Mental Workload and Work Ability Index

    PubMed Central

    Safari, Shahram; Akbari, Jafar; Kazemi, Meghdad; Mououdi, Mohammad Amin; Mahaki, Behzad

    2013-01-01

    Introduction. Two great changes in developed countries are taking place: populations are ageing and becoming increasingly overweight. Combination of these factors with shift work is a risk factor for work ability and mental workload that are dynamic processes which change greatly throughout an individual's work life. The aim of this study was to investigate mental workload and work ability in textile workers and to identify factors which affect work ability and mental workload. Methods. This cross-sectional study was carried out among 194 male workers in textile industry. Employees based on their job group and work conditions have been divided into 6 categories. They completed work ability index and mental workload questionnaires during three work shifts. Body mass index (BMI) and demographic details were recorded. Results. All of the participants rated their work ability as moderate with high mental workload. The mean WAI and mental workload in age group were significant. The mean BMI was 25.5 kg/m2 (standard deviation 4.1) and the mean age was 40.22 years. There was a statistically significant correlation between work ability index and shift work. Conclusions. Unlike the previous study, a decrease point in WAI started in early age that may be due to life-style work and another psychological factor; on the other hand, NASA-TLX revealed high score in six subscales that can be another reason for low WAI. PMID:23956756

  4. Work ability index among healthcare personnel in a university hospital in Tehran, Iran.

    PubMed

    Mehrdad, R; Mazloumi, A; Arshi, S; Kazemi, Z

    2016-03-09

    Work ability is an important issue from a social point of view, as it is essential for workers health and welfare. This study aimed to determine work ability among healthcare personnel and to investigate its relationship with demographic and lifestyle-related factors. Data were collected using the Work Ability Index (WAI) questionnaire among 517 personnel of a hospital in Tehran, Iran. Findings showed a mean WAI of 40.3 (±5.2) for the study population. Work ability was significantly lower in the older personnel and higher for men. A significant correlation was observed between BMI and exercise activity and WAI score. Moreover, employees with experience of less than five years had significant higher work ability than those with 16-20 years of service. Considering the young study population, it seems the mean WAI is not as desirable. The use of lifestyle promoting programs, besides workplace interventions, can be an effective strategy to increase work ability among healthcare workers.

  5. Is health, measured by work ability index, affected by 12-hour rotating shift schedules?

    PubMed

    Yong, Mei; Nasterlack, Michael; Pluto, Rolf-Peter; Elmerich, Kathrin; Karl, Dorothee; Knauth, Peter

    2010-07-01

    Two forms of continuously forward rotating 12-h shift schedules exist at BASF's Ludwigshafen site. These shift schedules were compared with a daytime working system to investigate potential differential effects on employee's health status assessed with the Work Ability Index (WAI). In the 3 x 12 system, a 12-h day shift is followed 24 h later by a 12-h night shift, and after a day off the employee returns to the day shift. The 4 x 12 schedule follows the same pattern except that there are 2 days off between the night and next day shift. A total of 924 participants (278 3 x 12 and 321 4 x 12 shiftworkers and 325 day workers) were recruited. A self-administered questionnaire was used to obtain information about shiftwork schedule, demographic characteristics, and lifestyle and social factors, and the WAI was applied. The outcomes of interest were the WAI sum score and its seven dimensions. In examining the relationship with the WAI categories, a Proportional Odds Model (POM) was used to identify the potential determinants. Logistic regression models were used to estimate the impact of age on single dimensions of WAI after adjustment for potential confounding factors. Increasing age and obesity (BMI > or = 30) were the only significant determinants of poorer WAI. Although a positive association was found linking the second WAI dimension (work ability in relation to job demands) with age, an inverse association was demonstrated consistently between age and the third and fourth WAI dimensions, i.e., number of diagnosed diseases and estimated work impairment due to disease, after adjustment for potential confounders. The age-dependency was moderate overall, but seemed to be stronger among shift- than day workers, although this difference did not reach statistical significance. There was no significant differential impact of the working time systems on the WAI sum score or on the individual WAI dimensions. Thus, there is no indication of an excessive adverse health impact

  6. Stanford-Binet & WAIS IQ Differences and Their Implications for Adults with Intellectual Disability (aka Mental Retardation).

    PubMed

    Silverman, Wayne; Miezejeski, Charles; Ryan, Robert; Zigman, Warren; Krinsky-McHale, Sharon; Urv, Tiina

    2010-03-01

    Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the Stanford-Binet. Additional comparisons with other measures suggested that the WAIS might systematically underestimate severity of intellectual impairment. Implications of these findings are discussed regarding determination of disability status, estimating prevalence of ID, assessing dementia and aging-related cognitive declines, and diagnosis of ID in forensic cases involving a possible death penalty.

  7. Stanford-Binet & WAIS IQ Differences and Their Implications for Adults with Intellectual Disability (aka Mental Retardation)

    PubMed Central

    Silverman, Wayne; Miezejeski, Charles; Ryan, Robert; Zigman, Warren; Krinsky-McHale, Sharon; Urv, Tiina

    2010-01-01

    Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the Stanford-Binet. Additional comparisons with other measures suggested that the WAIS might systematically underestimate severity of intellectual impairment. Implications of these findings are discussed regarding determination of disability status, estimating prevalence of ID, assessing dementia and aging-related cognitive declines, and diagnosis of ID in forensic cases involving a possible death penalty. PMID:20401180

  8. Transcranial direct current stimulation (tDCS) of frontal cortex decreases performance on the WAIS-IV intelligence test.

    PubMed

    Sellers, Kristin K; Mellin, Juliann M; Lustenberger, Caroline M; Boyle, Michael R; Lee, Won Hee; Peterchev, Angel V; Fröhlich, Flavio

    2015-09-01

    Transcranial direct current stimulation (tDCS) modulates excitability of motor cortex. However, there is conflicting evidence about the efficacy of this non-invasive brain stimulation modality to modulate performance on cognitive tasks. Previous work has tested the effect of tDCS on specific facets of cognition and executive processing. However, no randomized, double-blind, sham-controlled study has looked at the effects of tDCS on a comprehensive battery of cognitive processes. The objective of this study was to test if tDCS had an effect on performance on a comprehensive assay of cognitive processes, a standardized intelligence quotient (IQ) test. The study consisted of two substudies and followed a double-blind, between-subjects, sham-controlled design. In total, 41 healthy adult participants were included in the final analysis. These participants completed the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) as a baseline measure. At least one week later, participants in substudy 1 received either bilateral tDCS (anodes over both F4 and F3, cathode over Cz, 2 mA at each anode for 20 min) or active sham tDCS (2 mA for 40 s), and participants in substudy 2 received either right or left tDCS (anode over either F4 or F3, cathode over Cz, 2 mA for 20 min). In both studies, the WAIS-IV was immediately administered following stimulation to assess for performance differences induced by bilateral and unilateral tDCS. Compared to sham stimulation, right, left, and bilateral tDCS reduced improvement between sessions on Full Scale IQ and the Perceptual Reasoning Index. This demonstration that frontal tDCS selectively degraded improvement on specific metrics of the WAIS-IV raises important questions about the often proposed role of tDCS in cognitive enhancement. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Work Ability Index predicts application for disability pension after work-related medical rehabilitation for chronic back pain.

    PubMed

    Bethge, Matthias; Gutenbrunner, Christoph; Neuderth, Silke

    2013-11-01

    To determine whether the Work Ability Index (WAI), a short 7-item self-report questionnaire addressing issues of perceived disability, impairment, and expectations for resuming work, predicts application for disability pension, recommendations for further treatment, and other adverse work-related criteria in patients with chronic back pain after rehabilitation. Cohort study with 3-month follow-up. Seven inpatient rehabilitation centers. Patients (N=294; 168 women; mean age, 49.9y) with chronic back pain. The WAI was completed at the beginning of rehabilitation. All patients were treated according to the German rehabilitation guidelines for chronic back pain and work-related medical rehabilitation. Application for disability pension, as assessed by a postal questionnaire 3 months after discharge. Receiver operating characteristic curve analysis of the association between the WAI at baseline and subsequent application for disability pension revealed an area under the curve of .80 (95% confidence interval [CI], .62-.97). Youden index was highest when the WAI cutoff value was ≤20 points (sensitivity, 72.7%; specificity, 82.2%; total correct classification, 81.7%). After adjusting for age and sex, persons with a baseline WAI score of ≤20 points had 15.6 times (95% CI, 3.6-68.2) higher odds of subsequent application for disability pension, 4.9 times (95% CI, 1.5-16.8) higher odds of unemployment, and 6 times (95% CI, 2.4-15.2) higher odds of long-term sick leave at follow-up. The WAI could help rehabilitation professionals identify patients with back pain with a high risk of a subsequent application for disability pension. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  10. WAIS-IV Subtest Covariance Structure: Conceptual and Statistical Considerations

    ERIC Educational Resources Information Center

    Ward, L. Charles; Bergman, Maria A.; Hebert, Katina R.

    2012-01-01

    D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning,…

  11. VLBI survey of compact broad absorption line quasars with balnicity index BI = 0

    NASA Astrophysics Data System (ADS)

    Cegłowski, M.; Kunert-Bajraszewska, M.; Roskowiński, C.

    2015-06-01

    We present high-resolution observations, using both the European VLBI Network (EVN) at 1.7 GHz and the Very Long Baseline Array (VLBA) at 5 and 8.4 GHz, to image radio structures of 14 compact sources classified as broad absorption line (BAL) quasars based on the absorption index (AI). All sources but one were resolved, with the majority showing core-jet morphology typical for radio-loud quasars. We discuss in detail the most interesting cases. The high radio luminosities and small linear sizes of the observed objects indicate they are strong young active galactic nuclei. Nevertheless, the distribution of the radio-loudness parameter, log RI, of a larger sample of AI quasars shows that the objects observed by us constitute the most luminous, small subgroup of the AI population. Additionally, we report that for the radio-loudness parameter, the distribution of AI quasars and that for those selected using the traditional balnicity index differ significantly. Strong absorption is connected with lower log RI and thus probably larger viewing angles. Since the AI quasars have on average larger log RI, the orientation can mean that we see them less absorbed. However, we suggest that the orientation is not the only parameter that affects the detected absorption. That the strong absorption is associated with the weak radio emission is equally important and worth exploring.

  12. Dark plasmonic mode based perfect absorption and refractive index sensing.

    PubMed

    Yang, W H; Zhang, C; Sun, S; Jing, J; Song, Q; Xiao, S

    2017-07-06

    Dark plasmonic resonances in metallic nanostructures are essential for many potential applications such as refractive index sensing, single molecule detection, nanolasers etc. However, it is difficult to excite the dark modes in optical experiments and thus the practical applications are severely limited. Herein, we demonstrate a simple method to experimentally excite the quadrupolar and higher-order plasmonic modes with normal incident light. By directionally depositing silver films onto the sidewalls of metal-covered one-dimensional grating, we have experimentally observed a series of asymmetrical resonances at the plasmonic ranges of silver gratings. Interestingly, both of the reflection and transmission coefficients of high-order plasmonic modes are reduced to around zero, demonstrating the perfect absorption very well. The corresponding numerical simulations show that these resonances are the well-known dark modes. Different from the conventional dark modes in plasmonic dimers, here the dark modes are the electric oscillations (as standing waves) within the silver sidewalls that are excited by charge accumulation via the bright plasmonic resonance of the top silver strips. In addition to the simple realization of perfect absorption, the dark modes are found to be quite sensitive to the environmental changes. The experimentally measured reflective index sensitivity is around 458 nm per RIU (refractive index unit), which is much higher than the sensitivity of the metal-covered grating without silver sidewalls. This research shall pave new routes to practical applications of dark surface plasmons.

  13. Shortened version of the work ability index to identify workers at risk of long-term sickness absence.

    PubMed

    Schouten, Lianne S; Bültmann, Ute; Heymans, Martijn W; Joling, Catelijne I; Twisk, Jos W R; Roelen, Corné A M

    2016-04-01

    The Work Ability Index (WAI) identifies non-sicklisted workers at risk of future long-term sickness absence (LTSA). The WAI is a complicated instrument and inconvenient for use in large-scale surveys. We investigated whether shortened versions of the WAI identify non-sicklisted workers at risk of LTSA. Prospective study including two samples of non-sicklisted workers participating in occupational health checks between 2010 and 2012. A heterogeneous development sample (N= 2899) was used to estimate logistic regression coefficients for the complete WAI, a shortened WAI version without the list of diseases, and single-item Work Ability Score (WAS). These three instruments were calibrated for predictions of different (≥2, ≥4 and ≥6 weeks) LTSA durations in a validation sample of non-sicklisted workers (N= 3049) employed at a steel mill, differentiating between manual (N= 1710) and non-manual (N= 1339) workers. The discriminative ability was investigated by receiver operating characteristic analysis. All three instruments under-predicted the LTSA risks in both manual and non-manual workers. The complete WAI discriminated between individuals at high and low risk of LTSA ≥2, ≥4 and ≥6 weeks in manual and non-manual workers. Risk predictions and discrimination by the shortened WAI without the list of diseases were as good as the complete WAI. The WAS showed poorer discrimination in manual and non-manual workers. The WAI without the list of diseases is a good alternative to the complete WAI to identify non-sicklisted workers at risk of future LTSA durations ≥2, ≥4 and ≥6 weeks. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  14. Work Ability Index as tool to identify workers at risk of premature work exit.

    PubMed

    Roelen, Corné A M; Heymans, Martijn W; Twisk, Jos W R; van der Klink, Jac J L; Groothoff, Johan W; van Rhenen, Willem

    2014-12-01

    To investigate the Work Ability Index (WAI) as tool for identifying workers at risk of premature work exit in terms of disability pension, unemployment, or early retirement. Prospective cohort study of 11,537 male construction workers (mean age 45.5 years), who completed the WAI at baseline and reported their work status (employed, unemployed, disability pension, or retired) after mean 2.3 years of follow-up. Associations between WAI scores and work status were investigated by multinomial logistic regression analysis. The ability of the WAI to discriminate between workers at high and low risk of premature work exit was analyzed by the area (AUC) under the receiver operating characteristic curve. 9,530 (83 %) construction workers had complete data for analysis. At follow-up, 336 (4 %) workers reported disability pension, 125 (1 %) unemployment, and 255 (3 %) retirement. WAI scores were prospectively associated with the risk of disability pension at follow-up, but not with the risk of unemployment and early retirement. The WAI showed fair discrimination to identify workers at risk of disability pension [AUC = 0.74; 95 % confidence interval (CI) 0.70-0.77]. The discriminative ability decreased with age from AUC = 0.78 in workers aged 30-39 years to AUC = 0.69 in workers ≥50 years of age. Discrimination failed for unemployment (AUC = 0.51; 95 % CI 0.47-0.55) and early retirement (AUC = 0.58; 95 % CI 0.53-0.61). The WAI can be used to identify construction workers <50 years of age at increased risk of disability pension and invite them for preventive interventions.

  15. Are chronotype, social jetlag and sleep duration associated with health measured by Work Ability Index?

    PubMed

    Yong, Mei; Fischer, Dorothee; Germann, Christina; Lang, Stefan; Vetter, Céline; Oberlinner, Christoph

    The present study investigates the impact of chronotype, social jetlag and sleep duration on self-perceived health, measured by Work Ability Index (WAI), within an industrial setting. Between 2011 and 2013, 2474 day and shift workers participated in a health check offered by an occupational health promotion program and filled out the Munich ChronoType Questionnaire (adapted to the rotational 12-h schedule for shift workers) and the WAI. We computed sleep duration on work and free days, chronotype, and social jetlag. We used linear regression models to examine chronotype, sleep duration and social jetlag for association with the WAI sum score, and proportional odds models to estimate the combined effect of social jetlag and sleep duration. Participants reported an average daily sleep duration of 7.35 h (SD: 1.2 h), had an average chronotype of 3:08 a.m. (SD: 1 h), and the average social jetlag corresponded to 1.96 h (SD: 2.05 h). Increasing social jetlag and shorter sleep duration were independently associated with a decreasing WAI, while chronotype per se was not associated with WAI. Short sleep duration combined with high social jetlag significantly increased the risk of poor WAI (OR = 1.36; 95% CI: 1.09-1.72), while long sleep duration and high social jetlag were not associated with poor WAI (OR = 1.09; 95% CI: 0.88-1.35). Our results add to a growing body of literature, suggesting that circadian misalignment, but not chronotype per se, may be critical for health. Our results indicate that longer sleep may override the adverse effects of social jetlag on WAI.

  16. [Job satisfaction and work ability index in nurses].

    PubMed

    Viola, Fiorella; Larese Filon, Francesca

    2015-01-22

    Job satisfaction and work ability are important in the nursing profession to ensure good working conditions and to reduce work-related diseases and illness. Psychosocial factors such as social support and decision latitude (autonomy) could have a role in cardiovascular diseases, low back pain, injuries and sick leave. To evaluate work ability, job satisfaction, psychosocial factors and diseases in 10 departments of the Monfalcone Hospital. The Work Ability Index (WAI) questionnaire and Karasek Job Content Questionnaire with other questions related to working conditions and diseases were administered to 160 nurses working in 10 departments. The response rate was 90%. SPSS Statistic packaging was used for statistical analysis. The study population had a mean age of 41.1 ± 7 years and the majority were female (81.25%). WAI gave a rating of over 37 points (good and excellent) for 86.4%, with an average of 39.9 ± 5.9 in women and 40.6 ± 6.4 in men. The WAI differences between the departments were significant with Medicine and Surgery showing lower values (p=0.012). WAI was significantly lower in subjects with sick leave higher than 10 days per year (p=0.000) and in subjects with cardiovascular diseases (p=0.031). Our study showed very good working conditions for nurses. A follow-up of the analyzed population over time will add further information on this aspect.

  17. Test-Retest Gains in WAIS Scores after Four Retest Intervals.

    ERIC Educational Resources Information Center

    Catron, David W.; Thompson, Claudia C.

    1979-01-01

    To analyze the hypothesis that retest gain scores would decrease in a decelerating curve to zero-gain as the retest interval increased, male college students were administered the WAIS on two occasions with a retest at either 1 week, 2 months, or 4 months. (Author/SJL)

  18. Stanford-Binet and WAIS IQ Differences and Their Implications for Adults with Intellectual Disability (aka Mental Retardation)

    ERIC Educational Resources Information Center

    Silverman, Wayne; Miezejeski, Charles; Ryan, Robert; Zigman, Warren; Krinsky-McHale, Sharon; Urv, Tiina

    2010-01-01

    Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the…

  19. Predictive validity of the Work Ability Index and its individual items in the general population.

    PubMed

    Lundin, Andreas; Leijon, Ola; Vaez, Marjan; Hallgren, Mats; Torgén, Margareta

    2017-06-01

    This study assesses the predictive ability of the full Work Ability Index (WAI) as well as its individual items in the general population. The Work, Health and Retirement Study (WHRS) is a stratified random national sample of 25-75-year-olds living in Sweden in 2000 that received a postal questionnaire ( n = 6637, response rate = 53%). Current and subsequent sickness absence was obtained from registers. The ability of the WAI to predict long-term sickness absence (LTSA; ⩾ 90 consecutive days) during a period of four years was analysed by logistic regression, from which the Area Under the Receiver Operating Characteristic curve (AUC) was computed. There were 313 incident LTSA cases among 1786 employed individuals. The full WAI had acceptable ability to predict LTSA during the 4-year follow-up (AUC = 0.79; 95% CI 0.76 to 0.82). Individual items were less stable in their predictive ability. However, three of the individual items: current work ability compared with lifetime best, estimated work impairment due to diseases, and number of diagnosed current diseases, exceeded AUC > 0.70. Excluding the WAI item on number of days on sickness absence did not result in an inferior predictive ability of the WAI. The full WAI has acceptable predictive validity, and is superior to its individual items. For public health surveys, three items may be suitable proxies of the full WAI; current work ability compared with lifetime best, estimated work impairment due to diseases, and number of current diseases diagnosed by a physician.

  20. Atmospheric CO2 Over the Last 1000 Years: WAIS Divide Ice Core Record

    NASA Astrophysics Data System (ADS)

    Ahn, J.; Brook, E. J.

    2009-04-01

    How atmospheric CO2 varied over the last thousands years is of great interest because we may see not only natural, but also anthropogenic variations (Ruddiman, Climatic Change, 2003). The Law Dome ice cores reveal decadal to centennial variations in CO2 over the last 2000 years (MacFarling Meure et al., Geophys. Res. Lett., 2006). However, these variations have not yet been well confirmed in other ice core records. Here we use a newly drilled WAIS Divide ice core, which is ideal for this purpose because WAIS Divide has relatively high snow accumulation rate and small gas age distribution that allow us to observe decadal CO2 variations with minimal damping. We have started an extensive study of CO2 in WAIS Divide core. So far we have obtained data for 960-1940 A.D. from the WDC05-A core drilled in 2005-2006. 344 ice samples from 103 depths were analyzed and the standard error of the mean is ~0.8 ppm on average. Ancient air in 8~12 g of bubbly ice is liberated by crushing with steel pins at -35 °C and trapped in stainless steel tubes at -262 °C. CO2 mixing ratio in the extracted air is precisely determined using a gas chromatographic method. Details of the high-precision methods are described in Ahn et al. (J. of Glaciology, in press). Our new results show preindustrial atmospheric CO2 variability of ~ 10 ppm. The most striking feature of the record is a rapid atmospheric CO2 decrease of 7~8 ppm within ~20 years at ~ 1600 A.D. Considering the larger smoothing of gas records in the WAIS Divide relative to Law Dome, our results confirm the atmospheric CO2 decrease of ~10 ppm in Law Dome records observed at this time. However, this event is not significant in the Dronning Maud Land ice core (Siegenthaler et al., Tellus, 2005), probably due to more extensive smoothing of gas records in the core. Similar rapid changes of CO2 at other times in the WAIS Divide record need to be confirmed with higher resolution studies. We also found that our WAIS Divide CO2 data are

  1. Factor Analysis of the WAIS and Twenty French-Kit Reference Tests.

    ERIC Educational Resources Information Center

    Ramsey, Philip H.

    1979-01-01

    The Wechsler Adult Intelligence Scale (WAIS) and 20 tests from the French Kit were administered to over 100 undergraduates. Analyses revealed ten factors: verbal comprehension, visualization, memory span, syllogistic reasoning, general reasoning, induction, mechanical knowledge, number facility, spatial orientation, and associative memory.…

  2. WAIS Performance in Unincarcerated Groups of MMPI-Defined Sociopaths and Normal Controls

    ERIC Educational Resources Information Center

    Allain, Albert N.

    1974-01-01

    This investigation examines WAIS performance in groups of 32 sociopaths and 33 normal controls defined by Minnesota Multiphasic Personality Inventory criteria. Sociopaths and normal controls show no differences in overall level of intellectual functioning. (Author)

  3. Brief Report: The Use of WAIS-III in Adults with HFA and Asperger Syndrome

    PubMed Central

    Scholte, Evert M.; van Berckelaer-Onnes, Ina A.

    2007-01-01

    The WAIS III was administered to 16 adults with high functioning autism (HFA) and 27 adults with Asperger syndrome. Differences between Verbal Intelligence (VIQ) and Performance Intelligence (PIQ) were not found. Processing Speed problems in people with HFA appeared. At the subtest level, the Asperger syndrome group performed weak on Digit Span. Comprehension and Block Design were relative strengths. In the HFA group, performance on Digit-Symbol Coding and Symbol Search was relatively poor. Strengths were found on Information and Matrix Reasoning. The results suggest that the VIQ-PIQ difference cannot distinguish between HFA and Asperger syndrome. WAIS III Factor Scale and Subtest patterning provides a more valid indicator. PMID:17879152

  4. Nonscanning Moiré deflectometry for measurement of nonlinear refractive index and absorption coefficient of liquids.

    PubMed

    Farahani, Shahrzad Shahrabi; Madanipour, Khosro; Koohian, Ata

    2017-05-01

    In this work, a nonscanning measurement technique is presented for determining the nonlinear refractive index and absorption coefficient of liquid media based on Moiré deflectometry. In the proposed method two lasers are used: a low power, wide beam as probe and a high power with specific wavelength as a pump. Interaction of the pump laser beam with the nonlinear sample changes the refractive index, which leads to change in convergence/divergence of the collimated incident probe laser beam. The induced deflection is monitored by Moiré deflectometry. If the pump laser has a Gaussian intensity profile, the refractive index profile of the sample is Gaussian, too. Measuring the deflection angle of the probe beam by Moiré fringes deflection, and by using the inverse Abel transform integral, the refractive index profile and nonlinear refractive index can be determined. This method is fast, easy, and insensitive to environmental noise and allows real-time measurement. Also, the refractive index profile of the interacted medium with pump laser can be achieved by this technique. As a liquid sample, a DCJ dye in water solution was studied. The value of nonlinear refractive index, n2, and absorption coefficient, α, were obtained -2.54×10-4  cm2 w-1 and 1.368  cm-1, respectively.

  5. The Work Ability Index as a screening tool to identify the need for rehabilitation: longitudinal findings from the Second German Sociomedical Panel of Employees.

    PubMed

    Bethge, Matthias; Radoschewski, Friedrich Michael; Gutenbrunner, Christoph

    2012-11-01

    To evaluate the predictive value of the Work Ability Index (WAI) for different indicators of the need for rehabilitation at 1-year follow-up. Cohort study. Data were obtained from the Second German Sociomedical Panel of Employees, a large-scale cohort study with postal surveys in 2009 and 2010. A total of 457 women and 579 men were included. Confirmatory factor analysis confirmed the one-dimensionality of the WAI. Regression analyses showed that poor and moderate baseline WAI scores were associated with lower health-related quality of life and more frequent use of primary healthcare 1 year later. Subjects with poor baseline work ability had 4.6 times higher odds of unemployment and 12.2 times higher odds of prolonged sick leave than the reference group with good or excellent baseline work ability. Moreover, the odds of subjectively perceived need for rehabilitation, intention to request rehabilitation and actual use of rehabilitation services were 9.7, 5.7 and 3 times higher in the poor baseline WAI group and 5.5, 4 and 1.8 times higher in the moderate baseline WAI group, respectively. A WAI score ≤ 37 was identified as the optimal cut-off to predict the need for rehabilitation. The WAI is a valid screening tool for identifying the need for rehabilitation.

  6. The effects of work-related and individual factors on the Work Ability Index: a systematic review.

    PubMed

    van den Berg, T I J; Elders, L A M; de Zwart, B C H; Burdorf, A

    2009-04-01

    This paper systematically reviews the scientific literature on the effects of individual and work-related factors on the Work Ability Index (WAI). Studies on work ability published from 1985 to 2006 were identified through a structured search in PubMed, and Web of Science. Studies were included if the WAI was used as measure of work ability and if quantitative information was presented on determinants of work ability. In total, 20 studies were included with 14 cross-sectional studies and six longitudinal studies. Factors associated with poor work ability, as defined by WAI, were lack of leisure-time vigorous physical activity, poor musculoskeletal capacity, older age, obesity, high mental work demands, lack of autonomy, poor physical work environment, and high physical work load. The WAI is associated with individual characteristics, lifestyle, demands at work, and physical condition. This multifactorial nature of work ability should be taken into account in health promotion programmes aimed at maintaining and promoting the participation of the labour force and improvement of the performance at work.

  7. Investigation of the factor structure of the Wechsler Adult Intelligence Scale--Fourth Edition (WAIS-IV): exploratory and higher order factor analyses.

    PubMed

    Canivez, Gary L; Watkins, Marley W

    2010-12-01

    The present study examined the factor structure of the Wechsler Adult Intelligence Scale--Fourth Edition (WAIS-IV; D. Wechsler, 2008a) standardization sample using exploratory factor analysis, multiple factor extraction criteria, and higher order exploratory factor analysis (J. Schmid & J. M. Leiman, 1957) not included in the WAIS-IV Technical and Interpretation Manual (D. Wechsler, 2008b). Results indicated that the WAIS-IV subtests were properly associated with the theoretically proposed first-order factors, but all but one factor-extraction criterion recommended extraction of one or two factors. Hierarchical exploratory analyses with the Schmid and Leiman procedure found that the second-order g factor accounted for large portions of total and common variance, whereas the four first-order factors accounted for small portions of total and common variance. It was concluded that the WAIS-IV provides strong measurement of general intelligence, and clinical interpretation should be primarily at that level.

  8. Conceptual elaboration versus direct lexical access in WAIS-similarities: differential effects of white-matter lesions and gray matter volumes.

    PubMed

    Fernaeus, Sven-Erik; Hellström, Åke

    2017-09-18

    Wechsler Adult Intelligence Scale (WAIS) subscale Similarities have been classified as a test of either verbal comprehension or of inductive reasoning. The reason may be that items divide into two categories. We tested the hypothesis of heterogeneity of items in WAIS-Similarities. Consecutive patients at a memory clinic and healthy controls participated in the study. White-matter hyperintensities (WMHs) and normalized temporal lobe volumes were measured based on Magnetic resonance Imaging (MRI), and tests of verbal memory and attention were used in addition to WAIS-Similarities to collect behavioural data. Factor analysis supported the hypothesis that two factors are involved in the performance of WAIS-similarities: (1) semiautomatic lexical access and (2) conceptual elaboration. These factors were highly correlated but provided discriminative diagnostic information: In logistic regression analyses, scores of the lexical access factor and of the conceptual elaboration factor discriminated patients with mild cognitive impairment from Alzheimer's disease patients and from healthy controls, respectively. High scores of WMH, indicating periventricular white-matter lesions, predicted factor scores of direct lexical access but not those of conceptual elaboration, which were predicted only by medial and lateral temporal lobe volumes.

  9. Relationship of Education and IQ in the WAIS-R Standardization Sample.

    ERIC Educational Resources Information Center

    Matarazzo, Joseph D.; Herman, David O.

    1984-01-01

    Analyzed the total number of years of schooling completed against the Verbal IQ (VIQ), Performance IQ (PIQ), and Full Scale IQ (FSIQ) of the 1,880 individuals who were used to standardize the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Analysis revealed a progressive increase in mean FSIQ with increasing education. (JAC)

  10. Deterioration of intelligence in methamphetamine-induced psychosis: comparison with alcohol dependence on WAIS-III.

    PubMed

    Lin, Shih-Ku; Huang, Ming-Chy; Lin, Hui-Che; Pan, Chun-Hong

    2010-02-01

    Long-term use of methamphetamine could induce psychosis, but consequences with regards to intelligence have seldom been investigated. Long-term use of alcohol could also result in intellectual deterioration. The IQ of 34 methamphetamine-induced psychosis (MIP) patients (age, 28.7 +/- 6.1 years) and 34 alcohol-dependent (AD) patients (age, 40.7 +/- 7.3 years) was compared using the Chinese version of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). The average full-scale IQ, verbal IQ, performance IQ, verbal comprehension index, working memory index, perceptual organization index, and processing speed index was 82.3 +/- 10.8, 84.3 +/- 11.9, 81.9 +/- 12.1, 85.5 +/- 11.9, 84.7 +/- 12.5, 85.4 +/- 13.6, and 78.5 +/- 12.7 in MIP patients and 90.5 +/- 12.0, 95.2 +/- 11.3, 86.0 +/- 13.7, 95.5 +/- 11.0, 87.1 +/- 14.5, 96.2 +/- 13.1, and 84.5 +/- 15.0 in AD patients, respectively. There were six MIP patients (17.6%) whose full-scale IQ was <70 and 13 (38.2%) whose full-scale IQ was <85 and >70, while one AD patient had a full-scale IQ <70 (2.9%) and 10 (22%) had full-scale IQ <85 and >70. Long-term use of methamphetamine can result not only in psychosis, but also in mentality deterioration. Intelligence deterioration is more severe in clinical MIP patients than AD patients. Assessment of the mentality of MIP patients is suggested to help with the implementation of rehabilitative programs for these patients.

  11. 'Ike Wai Professional Development Model for Students and Post-docs

    NASA Astrophysics Data System (ADS)

    Bruno, B. C.

    2016-12-01

    'Ike Wai: Securing Hawaii's Water Future, funded by NSF EPSCoR, is an interdisciplinary research collaboration among geophysicists, geochemists, engineers, microbiologists, computational modelers, data scientists and social scientists. Key questions include: How much water is there? How does it flow? How long will it last? Undergraduate students, graduate students and post-docs are actively involved in the research, and their professional development is a key part of the project. An underlying principle is that students assume responsibility for their own learning and professional development. Based on the model created by the NSF Center for Microbial Oceanography: Research and Education (C-MORE) (Bruno et al, 2008; Guannel et al 2014, Bottjer et al 2014), the 'Ike Wai professional development program includes (1) Leadership. Each student and post-doc creates an Individualized Professional Development plan, which includes leadership training (provided by external facilitators) and assuming leadership roles (such as developing and implementing trainings for their peers). (2) EDventures. Based on the C-MORE model, EDventures combines proposal-writing training with the incentive of seed money. Rather than providing training a priori, the EDventures model encourages students and post-docs to write a proposal based on guidelines provided. Training occurs during a two-stage review stage: proposers respond to panel reviews and resubmit their proposal within a single review cycle. C-MORE EDventures alumni self-report statistically significant confidence gains on all questions posed. Their subsequent proposal success is envious: of the 12 proposals submitted by to NSF, 50% were funded. (Wood Charlson & Bruno, 2015) (3) Layered Mentoring Network. All ´Ike Wai participants serve as both mentor and mentee. Students are matched with a non-research mentor in addition to their advisor to promote a holistic approach to career development. They will also serve as mentors to more

  12. Dependent scattering and absorption by densely packed discrete spherical particles: Effects of complex refractive index

    NASA Astrophysics Data System (ADS)

    Ma, L. X.; Tan, J. Y.; Zhao, J. M.; Wang, F. Q.; Wang, C. A.; Wang, Y. Y.

    2017-07-01

    Due to the dependent scattering and absorption effects, the radiative transfer equation (RTE) may not be suitable for dealing with radiative transfer in dense discrete random media. This paper continues previous research on multiple and dependent scattering in densely packed discrete particle systems, and puts emphasis on the effects of particle complex refractive index. The Mueller matrix elements of the scattering system with different complex refractive indexes are obtained by both electromagnetic method and radiative transfer method. The Maxwell equations are directly solved based on the superposition T-matrix method, while the RTE is solved by the Monte Carlo method combined with the hard sphere model in the Percus-Yevick approximation (HSPYA) to consider the dependent scattering effects. The results show that for densely packed discrete random media composed of medium size parameter particles (equals 6.964 in this study), the demarcation line between independent and dependent scattering has remarkable connections with the particle complex refractive index. With the particle volume fraction increase to a certain value, densely packed discrete particles with higher refractive index contrasts between the particles and host medium and higher particle absorption indexes are more likely to show stronger dependent characteristics. Due to the failure of the extended Rayleigh-Debye scattering condition, the HSPYA has weak effect on the dependent scattering correction at large phase shift parameters.

  13. New method to determine the refractive index and the absorption coefficient of organic nonlinear crystals in the ultra-wideband THz region.

    PubMed

    Ohno, Seigo; Miyamoto, Katsuhiko; Minamide, Hiroaki; Ito, Hiromasa

    2010-08-02

    A method for simultaneously measuring the refractive index and absorption coefficient of nonlinear optical crystals in the ultra-wideband terahertz (THz) region is described. This method is based on the analysis of a collinear difference frequency generation (DFG) process using a tunable, dual-wavelength, optical parametric oscillator. The refractive index and the absorption coefficient in the organic nonlinear crystal DAST were experimentally determined in the frequency range 2.5-26.2 THz by measuring the THz-wave output using DFG. The resultant refractive index in the x-direction was approximately 2.3, while the absorption spectrum was in good agreement with FT-IR measurements. The output of the DAST-DFG THz-wave source was optimized to the phase-matching condition using the measured refractive index spectrum in THz region, which resulted in an improvement in the output power of up to a factor of nine.

  14. The Use of WAIS-III in Adults with HFA and Asperger Syndrome

    ERIC Educational Resources Information Center

    Spek, Antoinette A.; Scholte, Evert M.; van Berckelaer-Onnes, Ina A.

    2008-01-01

    The WAIS III was administered to 16 adults with high functioning autism (HFA) and 27 adults with Asperger syndrome. Differences between Verbal Intelligence (VIQ) and Performance Intelligence (PIQ) were not found. Processing Speed problems in people with HFA appeared. At the subtest level, the Asperger syndrome group performed weak on Digit Span.…

  15. The influence of IQ stratification on WAIS-III/WMS-III FSIQ-general memory index discrepancy base-rates in the standardization sample.

    PubMed

    Hawkins, K A; Tulsky, D S

    2001-11-01

    Since memory performance expectations may be IQ-based, unidirectional base rate data for IQ-Memory Score discrepancies are provided in the WAIS-III/WMS-III Technical Manual. The utility of these data partially rests on the assumption that discrepancy base rates do not vary across ability levels. FSIQ stratified base rate data generated from the standardization sample, however, demonstrate substantial variability across the IQ spectrum. A superiority of memory score over FSIQ is typical at lower IQ levels, whereas the converse is true at higher IQ levels. These data indicate that the use of IQ-memory score unstratified "simple difference" tables could lead to erroneous conclusions for clients with low or high IQ. IQ stratified standardization base rate data are provided as a complement to the "predicted difference" method detailed in the Technical Manual.

  16. Norm comparisons of the Spanish-language and English-language WAIS-III: Implications for clinical assessment and test adaptation.

    PubMed

    Funes, Cynthia M; Rodriguez, Juventino Hernandez; Lopez, Steven Regeser

    2016-12-01

    This study provides a systematic comparison of the norms of 3 Spanish-language Wechsler Adult Intelligence Scales (WAIS-III) batteries from Mexico, Spain, and Puerto Rico, and the U.S. English-language WAIS-III battery. Specifically, we examined the performance of the 4 normative samples on 2 identical subtests (Digit Span and Digit Symbol-Coding) and 1 nearly identical subtest (Block Design). We found that across most age groups the means associated with the Spanish-language versions of the 3 subtests were lower than the means of the U.S. English-language version. In addition, we found that for most age ranges the Mexican subsamples scored lower than the Spanish subsamples. Lower educational levels of Mexicans and Spaniards compared to U.S. residents are consistent with the general pattern of findings. These results suggest that because of the different norms, applying any of the 3 Spanish-language versions of the WAIS-III generally risks underestimating deficits, and that applying the English-language WAIS-III norms risks overestimating deficits of Spanish-speaking adults. There were a few exceptions to these general patterns. For example, the Mexican subsample ages 70 years and above performed significantly better on the Digit Symbol and Block Design than did the U.S. and Spanish subsamples. Implications for the clinical assessment of U.S. Spanish-speaking Latinos and test adaptation are discussed with an eye toward improving the clinical care for this community. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  17. Evaluating WAIS-IV structure through a different psychometric lens: structural causal model discovery as an alternative to confirmatory factor analysis.

    PubMed

    van Dijk, Marjolein J A M; Claassen, Tom; Suwartono, Christiany; van der Veld, William M; van der Heijden, Paul T; Hendriks, Marc P H

    Since the publication of the WAIS-IV in the U.S. in 2008, efforts have been made to explore the structural validity by applying factor analysis to various samples. This study aims to achieve a more fine-grained understanding of the structure of the Dutch language version of the WAIS-IV (WAIS-IV-NL) by applying an alternative analysis based on causal modeling in addition to confirmatory factor analysis (CFA). The Bayesian Constraint-based Causal Discovery (BCCD) algorithm learns underlying network structures directly from data and assesses more complex structures than is possible with factor analysis. WAIS-IV-NL profiles of two clinical samples of 202 patients (i.e. patients with temporal lobe epilepsy and a mixed psychiatric outpatient group) were analyzed and contrasted with a matched control group (N = 202) selected from the Dutch standardization sample of the WAIS-IV-NL to investigate internal structure by means of CFA and BCCD. With CFA, the four-factor structure as proposed by Wechsler demonstrates acceptable fit in all three subsamples. However, BCCD revealed three consistent clusters (verbal comprehension, visual processing, and processing speed) in all three subsamples. The combination of Arithmetic and Digit Span as a coherent working memory factor could not be verified, and Matrix Reasoning appeared to be isolated. With BCCD, some discrepancies from the proposed four-factor structure are exemplified. Furthermore, these results fit CHC theory of intelligence more clearly. Consistent clustering patterns indicate these results are robust. The structural causal discovery approach may be helpful in better interpreting existing tests, the development of new tests, and aid in diagnostic instruments.

  18. Work ability index and perceived work ability as predictors of disability pension: a prospective study among Finnish municipal employees.

    PubMed

    Jääskeläinen, Anne; Kausto, Johanna; Seitsamo, Jorma; Ojajärvi, Anneli; Nygård, Clas-Håkan; Arjas, Elja; Leino-Arjas, Päivi

    2016-06-01

    We analyzed the work ability index (WAI) and its first item (work ability score, WAS) - and subsequent four-year changes thereof - as predictors of disability pension (DP). We linked survey responses of 5251 Finnish municipal employees, aged 44-58 years, to pension and death register data until 2009. Job content (physical, mental, or mixed) was based on observation. Baseline (1981) WAI was divided into poor (<27), moderate (28-36), and good/excellent (>37) and WAS into poor (0-5), moderate (6-7), and good/excellent (8-10). Four-year changes in these scores were classified as strong decline (WAI, the hazard ratio (HR) for DP related to moderate and poor WAI, respectively, was 2.0 (95% CI 1.8-2.2) and 5.0 (95% CI 4.4-5.6), adjusted for sociodemographic variables and job content. For WAS, the HR were 1.8 (95% CI 1.6-2.0) and 3.4 (95% 3.0-3.8). Four-year decline in WAI/WAS further increased the risk. During the first four years of follow-up, the area under the curve (AUC) for WAI at cut-off point 27 was 0.66 (sensitivity 49.2% and specificity 82.9%) and 0.64 for cut-off point 36 (sensitivity 84.2% and specificity 44.3%). For WAS at cut-off point 5, the figures were AUC 0.63 (sensitivity 41.9% and specificity 85.0%) and AUC 0.65 for cut-off point 7 (sensitivity 78.2% and specificity 52.7%). The single-item WAS can be considered a reasonable alternative to the seven-item WAI in describing the risk of DP and as a prognostic tool.

  19. Retrieval of canopy water content of different crop types with two new hyperspectral indices: Water Absorption Area Index and Depth Water Index

    NASA Astrophysics Data System (ADS)

    Pasqualotto, Nieves; Delegido, Jesús; Van Wittenberghe, Shari; Verrelst, Jochem; Rivera, Juan Pablo; Moreno, José

    2018-05-01

    Crop canopy water content (CWC) is an essential indicator of the crop's physiological state. While a diverse range of vegetation indices have earlier been developed for the remote estimation of CWC, most of them are defined for specific crop types and areas, making them less universally applicable. We propose two new water content indices applicable to a wide variety of crop types, allowing to derive CWC maps at a large spatial scale. These indices were developed based on PROSAIL simulations and then optimized with an experimental dataset (SPARC03; Barrax, Spain). This dataset consists of water content and other biophysical variables for five common crop types (lucerne, corn, potato, sugar beet and onion) and corresponding top-of-canopy (TOC) reflectance spectra acquired by the hyperspectral HyMap airborne sensor. First, commonly used water content index formulations were analysed and validated for the variety of crops, overall resulting in a R2 lower than 0.6. In an attempt to move towards more generically applicable indices, the two new CWC indices exploit the principal water absorption features in the near-infrared by using multiple bands sensitive to water content. We propose the Water Absorption Area Index (WAAI) as the difference between the area under the null water content of TOC reflectance (reference line) simulated with PROSAIL and the area under measured TOC reflectance between 911 and 1271 nm. We also propose the Depth Water Index (DWI), a simplified four-band index based on the spectral depths produced by the water absorption at 970 and 1200 nm and two reference bands. Both the WAAI and DWI outperform established indices in predicting CWC when applied to heterogeneous croplands, with a R2 of 0.8 and 0.7, respectively, using an exponential fit. However, these indices did not perform well for species with a low fractional vegetation cover (<30%). HyMap CWC maps calculated with both indices are shown for the Barrax region. The results confirmed the

  20. WAIS-R Verbal and Performance Profiles of Adolescents Referred for Atypical Learning Styles.

    ERIC Educational Resources Information Center

    Rush, Pamela; And Others

    This study investigated Wechsler Adult Intelligence Scale-Revised (WAIS-R) profiles of deaf adolescents referred for academic difficulties. In addition, differences between referral deaf students and non-referral deaf peers were explored. The sample consisted of 28 severely-to-profoundly hearing impaired students enrolled in the School of…

  1. Work ability as prognostic risk marker of disability pension: single-item work ability score versus multi-item work ability index.

    PubMed

    Roelen, Corné A M; van Rhenen, Willem; Groothoff, Johan W; van der Klink, Jac J L; Twisk, Jos W R; Heymans, Martijn W

    2014-07-01

    Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP. This prospective cohort study comprised 11 537 male construction workers, who completed the WAI at baseline and reported DP after a mean 2.3 years of follow-up. WAS and WAI were calibrated for DP risk predictions with the Hosmer-Lemeshow (H-L) test and their ability to discriminate between high- and low-risk construction workers was investigated with the area under the receiver operating characteristic curve (AUC). At follow-up, 336 (3%) construction workers reported DP. Both WAS [odds ratio (OR) 0.72, 95% confidence interval (95% CI) 0.66-0.78] and WAI (OR 0.57, 95% CI 0.52-0.63) scores were associated with DP at follow-up. The WAS showed miscalibration (H-L model χ (�)=10.60; df=3; P=0.01) and poorly discriminated between high- and low-risk construction workers (AUC 0.67, 95% CI 0.64-0.70). In contrast, calibration (H-L model χ �=8.20; df=8; P=0.41) and discrimination (AUC 0.78, 95% CI 0.75-0.80) were both adequate for the WAI. Although associated with the risk of future DP, the single-item WAS poorly identified male construction workers at risk of DP. We recommend using the multi-item WAI to screen for risk of DP in occupational health practice.

  2. Using Firn Air for Facility Cooling at the WAIS Divide Site

    DTIC Science & Technology

    2014-09-17

    reduce logistics costs at remote field camps where it is critical to maintain proper temperatures to preserve sensitive deep ice cores. We assessed the...feasibility of using firn air for cooling at the West Antarc- tic Ice Sheet (WAIS) Divide ice core drilling site as a means to adequately and...efficiently refrigerate ice cores during storage and processing. We used estimates of mean annual temperature, temperature variations, and firn

  3. Wechsler Adult Intelligence Scale-Third Edition short form for index and IQ scores in a psychiatric population.

    PubMed

    Christensen, Bruce K; Girard, Todd A; Bagby, R Michael

    2007-06-01

    An eight-subtest short form (SF8) of the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III), maintaining equal representation of each index factor, was developed for use with psychiatric populations. Data were collected from a mixed inpatient/outpatient sample (99 men and 101 women) referred for neuropsychological assessment. Psychometric analyses revealed an optimal SF8 comprising Vocabulary, Similarities, Arithmetic, Digit Span, Picture Completion, Matrix Reasoning, Digit Symbol Coding, and Symbol Search, scored by linear scaling. Expanding on previous short forms, the current SF8 maximizes the breadth of information and reduces administration time while maintaining the original WAIS-III factor structure. (c) 2007 APA, all rights reserved

  4. The work ability index and single-item question: associations with sick leave, symptoms, and health--a prospective study of women on long-term sick leave.

    PubMed

    Ahlstrom, Linda; Grimby-Ekman, Anna; Hagberg, Mats; Dellve, Lotta

    2010-09-01

    This study investigated the association between the work ability index (WAI) and the single-item question on work ability among women working in human service organizations (HSO) currently on long-term sick leave. It also examined the association between the WAI and the single-item question in relation to sick leave, symptoms, and health. Predictive values of the WAI, the changed WAI, the single-item question and the changed single-item question were investigated for degree of sick leave, symptoms, and health. This cohort study comprised 324 HSO female workers on long-term (>60 days) sick leave, with follow-ups at 6 and 12 months. Participants responded to questionnaires. Data on work ability, sick leave, health, and symptoms were analyzed with regard to associations and predictability. Spearman correlation and mixed-model analysis were performed for repeated measurements over time. The study showed a very strong association between the WAI and the single-item question among all participants. Both the WAI and the single-item question showed similar patterns of associations with sick leave, health, and symptoms. The predictive value for the degree of sick leave and health-related quality of life (HRQoL) was strong for both the WAI and the single-item question, and slightly less strong for vitality, neck pain, both self-rated general and mental health, and behavioral and current stress. This study suggests that the single-item question on work ability could be used as a simple indicator for assessing the status and progress of work ability among women on long-term sick leave.

  5. [Work stress, common mental disorders and Work Ability Index among call center workers of an Italian company].

    PubMed

    Conway, Paul Maurice; Campanini, Paolo; Punzi, Silvia; Fichera, Giuseppe Paolo; Camerino, Donatella; Francioli, Laura; Neri, Luca; Costa, Giovanni

    2013-01-01

    To test three hypotheses in an Italian sample of call center workers: higher levels of perceived work stress are associated with more frequent common mental disorders (GHQ-12) and a lower Work Ability Index; combining the Job Strain (JS) and Effort/Reward Imbalance (ERI) models increases explained variance in health over and above either model when applied separately; compared with outbound operators, inbound call handlers are expected to report a lower health status,which is due to a more intense exposure to task-related work stress factors in the latter. A multi-center cross-sectional study, conducted by means of interviews and self-administered questionnaires. Call handlers working in the Italian branch of a telecommunication multinational company. In all, 1,106 permanent workers were examined (35.9%of the total target population, 98.9% response rate). The majority were women (76.5%);mean age was 33.3 (SD: 3.9) and company seniority 8.0 (SD: 2.1). Nearly 60% worked as inbound call handlers, about one third as outbound operators. Work stress was measured with the well-known JS and ERI models. Three exposure levels (based on tertiles) were identified for each scale. Common mental disorders were measured with the GHQ-12 questionnaire. Subjects with a GHQ-12 score 4 were classified as "cases". The Work Ability Index (WAI) was used to evaluate work ability. Being in the "poor" or "moderate" categories of the WAI indicated a low work ability status. Cronbach's alphas were 0.70 for all scales. Multivariate Poisson regressions showed that both models were linked to more frequent common mental disorders and a lower WAI. Moreover, combined models demonstrated an advantage in terms of explained variance in health. Finally, performing inbound call handling was associated with a lower WAI in comparison with engaging in outbound activities. Mediation analyses showed that such association is explained by the higher levels of psychological job demands and Job Strain experienced

  6. Psychometric qualities of a tetrad WAIS-III short form for use in individuals with mild to borderline intellectual disability.

    PubMed

    van Duijvenbode, Neomi; Didden, Robert; van den Hazel, Teunis; Engels, Rutger C M E

    2016-01-01

    To investigate the reliability and validity of a Wechsler Abbreviated Scale of Intelligence-based Wechsler Adult Intelligence Scale - third edition (WAIS-III) short form (SF) in a sample of individuals with mild to borderline intellectual disability (MBID) (N = 117; M(IQ) = 71.34; SD(IQ) = 8.00, range: 52-85). A full WAIS-III was administered as a standard procedure in the diagnostic process. The results indicate an excellent reliability (r = 0.96) and a strong, positive correlation with the full WAIS-III (r = 0.89). The SF correctly identified ID in general and the correct IQ category more specifically in the majority of cases (97.4% and 86.3% of cases, respectively). In addition, 82.1% of the full scale IQ (FSIQ) estimates fell within the 95% confidence interval of the original score. We conclude that the SF is a reliable and valid measure to estimate FSIQ. It can be used in clinical and research settings when global estimates of intelligence are sufficient.

  7. Reflectance-mode interferometric near-infrared spectroscopy quantifies brain absorption, scattering, and blood flow index in vivo.

    PubMed

    Borycki, Dawid; Kholiqov, Oybek; Srinivasan, Vivek J

    2017-02-01

    Interferometric near-infrared spectroscopy (iNIRS) is a new technique that measures time-of-flight- (TOF-) resolved autocorrelations in turbid media, enabling simultaneous estimation of optical and dynamical properties. Here, we demonstrate reflectance-mode iNIRS for noninvasive monitoring of a mouse brain in vivo. A method for more precise quantification with less static interference from superficial layers, based on separating static and dynamic components of the optical field autocorrelation, is presented. Absolute values of absorption, reduced scattering, and blood flow index (BFI) are measured, and changes in BFI and absorption are monitored during a hypercapnic challenge. Absorption changes from TOF-resolved iNIRS agree with absorption changes from continuous wave NIRS analysis, based on TOF-integrated light intensity changes, an effective path length, and the modified Beer-Lambert Law. Thus, iNIRS is a promising approach for quantitative and noninvasive monitoring of perfusion and optical properties in vivo.

  8. Measuring Working Memory With Digit Span and the Letter-Number Sequencing Subtests From the WAIS-IV: Too Low Manipulation Load and Risk for Underestimating Modality Effects.

    PubMed

    Egeland, Jens

    2015-01-01

    The Wechsler Adult Intelligence Scale (WAIS) is one of the most frequently used tests among psychologists. In the fourth edition of the test (WAIS-IV), the subtests Digit Span and Letter-Number Sequencing are expanded for better measurement of working memory (WM). However, it is not clear whether the new extended tasks contribute sufficient complexity to be sensitive measures of manipulation WM, nor do we know to what degree WM capacity differs between the visual and the auditory modality because the WAIS-IV only tests the auditory modality. Performance by a mixed sample of 226 patients referred for neuropsychological examination on the Digit Span and Letter-Number Sequencing subtests from the WAIS-IV and on Spatial Span from the Wechsler Memory Scale-Third Edition was analyzed in two confirmatory factor analyses to investigate whether a unitary WM model or divisions based on modality or level/complexity best fit the data. The modality model showed the best fit when analyzing summed scores for each task as well as scores for the longest span. The clinician is advised to apply tests with higher manipulation load and to consider testing visual span as well before drawing conclusions about impaired WM from the WAIS-IV.

  9. [Application of WAIS-RC short forms and adult intelligence disability scale in mental impairment assessment].

    PubMed

    Pang, Yan-Xia; Zhang, Jian; Yang, Cheng-Long; Cang, Yong; Wang, Xue-Ling

    2011-06-01

    Study on the application of WAIS-RC short forms and adult intelligence disability scale in mental impairment assessment. Mental impairment assessment cases between July 2009 and March 2011 in judicial appraisal institute of Taizhou University were collected. Assessment results obtained with the WAIS-RC short forms and adult intelligence disability scale were compared with the experts assessing conclusions and analyzed using SPSS 11.5 software. Assessment results with the two scales did not fully comply with the expert's conclusions, with reliability coefficient were 0.785 and 0.940 respectively, correlation coefficient were 0.850 and 0.922 respectively. The intelligence assessment was influenced by many factors. When the appraised individuals had nerve dysfunction and mild intelligence disability or mental disorders, the two scales should be used together. When the appraised individuals had moderate intelligence disability or mental disorders, adult intelligence disability scale had advantage.

  10. Factor structure of the Norwegian version of the WAIS-III in a clinical sample: the arithmetic problem.

    PubMed

    Egeland, Jens; Bosnes, Ole; Johansen, Hans

    2009-09-01

    Confirmatory Factor Analyses (CFA) of the Wechsler Adult Intelligence Scale-III (WAIS-III) lend partial support to the four-factor model proposed in the test manual. However, the Arithmetic subtest has been especially difficult to allocate to one factor. Using the new Norwegian WAIS-III version, we tested factor models differing in the number of factors and in the placement of the Arithmetic subtest in a mixed clinical sample (n = 272). Only the four-factor solutions had adequate goodness-of-fit values. Allowing Arithmetic to load on both the Verbal Comprehension and Working Memory factors provided a more parsimonious solution compared to considering the subtest only as a measure of Working Memory. Effects of education were particularly high for both the Verbal Comprehension tests and Arithmetic.

  11. Reflectance-mode interferometric near-infrared spectroscopy quantifies brain absorption, scattering, and blood flow index in vivo

    PubMed Central

    Borycki, Dawid; Kholiqov, Oybek; Srinivasan, Vivek J.

    2017-01-01

    Interferometric near-infrared spectroscopy (iNIRS) is a new technique that measures time-of-flight- (TOF-) resolved autocorrelations in turbid media, enabling simultaneous estimation of optical and dynamical properties. Here, we demonstrate reflectance-mode iNIRS for noninvasive monitoring of a mouse brain in vivo. A method for more precise quantification with less static interference from superficial layers, based on separating static and dynamic components of the optical field autocorrelation, is presented. Absolute values of absorption, reduced scattering, and blood flow index (BFI) are measured, and changes in BFI and absorption are monitored during a hypercapnic challenge. Absorption changes from TOF-resolved iNIRS agree with absorption changes from continuous wave NIRS analysis, based on TOF-integrated light intensity changes, an effective path length, and the modified Beer–Lambert Law. Thus, iNIRS is a promising approach for quantitative and non-invasive monitoring of perfusion and optical properties in vivo. PMID:28146535

  12. Wechsler Adult Intelligence Scale-Third Edition Short Form for Index and IQ Scores in a Psychiatric Population

    ERIC Educational Resources Information Center

    Christensen, Bruce K.; Girard, Todd A.; Bagby, R. Michael

    2007-01-01

    An eight-subtest short form (SF8) of the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III), maintaining equal representation of each index factor, was developed for use with psychiatric populations. Data were collected from a mixed inpatient/outpatient sample (99 men and 101 women) referred for neuropsychological assessment. Psychometric…

  13. Work ability assessment in a worker population: comparison and determinants of Work Ability Index and Work Ability score.

    PubMed

    El Fassi, Mehdi; Bocquet, Valery; Majery, Nicole; Lair, Marie Lise; Couffignal, Sophie; Mairiaux, Philippe

    2013-04-08

    Public authorities in European countries are paying increasing attention to the promotion of work ability throughout working life and the best method to monitor work ability in populations of workers is becoming a significant question. The present study aims to compare the assessment of work ability based on the use of the Work Ability Index (WAI), a 7-item questionnaire, with another one based on the use of WAI's first item, which consists in the worker's self-assessment of his/her current work ability level as opposed to his/her lifetime best, this single question being termed "Work Ability score" (WAS). Using a database created by an occupational health service, the study intends to answer the following questions: could the assessment of work ability be based on a single-item measure and which are the variables significantly associated with self-reported work ability among those systematically recorded by the occupational physician during health examinations? A logistic regression model was used in order to estimate the probability of observing "poor" or "moderate" WAI levels depending on age, gender, body mass index, smoking status, position held, firm size and diseases reported by the worker in a population of workers aged 40 to 65 and examined between January 2006 and June 2010 (n=12389). The convergent validity between WAS and WAI was statistically significant (rs=0.63). In the multivariable model, age (p<0.001), reported diseases (OR=1.13, 95%CI [1.11-1.15]) and holding a position mostly characterized by physical activity (OR=1.67, 95%CI [1.49-1.87]) increased the probability of reporting moderate or poor work ability. A work position characterized by the predominance of mental activity (OR=0.71, 95%CI [0.61-0.84]) had a favourable impact on work ability. These relations were observed regardless of the work ability measurement tool used. The convergent validity and the similarity in results between WAI and WAS observed in a large population of employed

  14. Epilepsy & IQ: the clinical utility of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) indices in the neuropsychological assessment of people with epilepsy.

    PubMed

    Baxendale, Sallie; McGrath, Katherine; Thompson, Pamela J

    2014-01-01

    We examined Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) General Ability Index (GAI) and Full Scale Intelligence Quotient (FSIQ) discrepancies in 100 epilepsy patients; 44% had a significant GAI > FSIQ discrepancy. GAI-FSIQ discrepancies were correlated with the number of antiepileptic drugs taken and duration of epilepsy. Individual antiepileptic drugs differentially interfere with the expression of underlying intellectual ability in this group. FSIQ may significantly underestimate levels of general intellectual ability in people with epilepsy. Inaccurate representations of FSIQ due to selective impairments in working memory and reduced processing speed obscure the contextual interpretation of performance on other neuropsychological tests, and subtle localizing and lateralizing signs may be missed as a result.

  15. WAIS Digit Span-Based Indicators of Malingered Neurocognitive Dysfunction: Classification Accuracy in Traumatic Brain Injury

    ERIC Educational Resources Information Center

    Heinly, Matthew T.; Greve, Kevin W.; Bianchini, Kevin J.; Love, Jeffrey M.; Brennan, Adrianne

    2005-01-01

    The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n = 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND.…

  16. Better Service through Data: Wai Sze (Lacey) Chan--Queens Borough Public Library, Jamaica, NY

    ERIC Educational Resources Information Center

    Library Journal, 2004

    2004-01-01

    The New Americans Program at Queens Borough Public Library (QBPL) is well known for the innovative collections and programs it provides to one of the nation's most diverse communities. What is less known is the rigorous analysis of demographic data that provides direction to the program. Wai Sze (Lacey) Chan uses demographics to create as complete…

  17. Nonlinear Color–Metallicity Relations of Globular Clusters. VII. Nonlinear Absorption-line Index versus Metallicity Relations and Bimodal Index Distributions of NGC 5128 Globular Clusters

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

    Kim, Sooyoung; Yoon, Suk-Jin, E-mail: sjyoon0691@yonsei.ac.kr

    Spectroscopy on the globular cluster (GC) system of NGC 5128 revealed bimodality in absorption-line index distributions of its old GCs. GC division is a widely observed and studied phenomenon whose interpretation has depicted host galaxy formation and evolution such that it harbors two distinct metallicity groups. Such a conventional view of GC bimodality has mainly been based on photometry. The recent GC photometric data, however, presented an alternative perspective in which the nonlinear metallicity-to-color transformation is responsible for color bimodality of GC systems. Here we apply the same line of analysis to the spectral indices and examine the absorption-line indexmore » versus metallicity relations for the NGC 5128 GC system. NGC 5128 GCs display nonlinearity in the metallicity-index planes, most prominently for the Balmer lines and by a non-negligible degree for the metallicity-sensitive magnesium line. We demonstrate that the observed spectroscopic division of NGC 5128 GCs can be caused by the nonlinear nature of the metallicity-to-index conversions and thus one does not need to resort to two separate GC subgroups. Our analysis incorporating this nonlinearity provides a new perspective on the structure of NGC 5128's GC system, and a further piece to the global picture of the formation of GC systems and their host galaxies.« less

  18. A cross-cultural comparison between South African and British students on the Wechsler Adult Intelligence Scales Third Edition (WAIS-III).

    PubMed

    Cockcroft, Kate; Alloway, Tracy; Copello, Evan; Milligan, Robyn

    2015-01-01

    There is debate regarding the appropriate use of Western cognitive measures with individuals from very diverse backgrounds to that of the norm population. Given the dated research in this area and the considerable socio-economic changes that South Africa has witnessed over the past 20 years, this paper reports on the use of the Wechsler Adult Intelligence Scale Third Edition (WAIS-III), the most commonly used measure of intelligence, with an English second language, multilingual, low socio-economic group of black, South African university students. Their performance on the WAIS-III was compared to that of a predominantly white, British, monolingual, higher socio-economic group. A multi-group confirmatory factor analysis showed that the WAIS-III lacks measurement invariance between the two groups, suggesting that it may be tapping different constructs in each group. The UK group significantly outperformed the SA group on the knowledge-based verbal, and some non-verbal subtests, while the SA group performed significantly better on measures of Processing Speed (PS). The groups did not differ significantly on the Matrix Reasoning subtest and on those working memory subtests with minimal reliance on language, which appear to be the least culturally biased. Group differences were investigated further in a set of principal components analyses, which revealed that the WAIS-III scores loaded differently for the UK and SA groups. While the SA group appeared to treat the PS subtests differently to those measuring perceptual organization and non-verbal reasoning, the UK group seemed to approach all of these subtests similarly. These results have important implications for the cognitive assessment of individuals from culturally, linguistically, and socio-economically diverse circumstances.

  19. Enhancement and inhibition of second-harmonic generation and absorption in a negative index cavity.

    PubMed

    de Ceglia, Domenico; D'Orazio, Antonella; De Sario, Marco; Petruzzelli, Vincenzo; Prudenzano, Francesco; Centini, Marco; Cappeddu, Mirko G; Bloemer, Mark J; Scalora, Michael

    2007-02-01

    We study second-harmonic generation in a negative-index material cavity. The transmission spectrum shows a bandgap between the electric and magnetic plasma frequencies. The nonlinear process is made efficient by local phase-matching conditions between a forward-propagating pump and a backward-propagating second-harmonic signal. By simultaneously exciting the cavity with counterpropagating pulses, and by varying their relative phase difference, one is able to enhance or inhibit linear absorption and the second-harmonic conversion efficiency.

  20. Is the work ability index useful to evaluate absence days in ankylosing spondylitis patients? A cross-sectional study

    PubMed Central

    Meyer, Katharina; Niedermann, Karin; Tschopp, Alois; Klipstein, Andreas

    2013-01-01

    Background The work incapacity of ankylosing spondylitis (AS) ranges between 3% and 50% in Europe. In many countries, work incapacity is difficult to quantify. The work ability index (WAI) is applied to measure the work ability in workers, but it is not well investigated in patients. Aims To investigate the work incapacity in terms of absence days in patients with AS and to evaluate whether the WAI reflects the absence from work. Hypothesis Absence days can be estimated based on the WAI and other variables. Design Cross-sectional design. Setting In a secondary care centre in Switzerland, the WAI and a questionnaire about work absence were administered in AS patients prior to cardiovascular training. The number of absence days was collected retrospectively. The absence days were estimated using a two-part regression model. Participants 92 AS patients (58 men (63%)). Inclusion criteria: AS diagnosis, ability to cycle, age between 18 and 65 years. Exclusion criteria: severe heart disease. Primary and secondary outcome measures Absence days. Results Of the 92 patients, 14 received a disability pension and 78 were in the working process. The median absence days per year of the 78 patients due to AS alone and including other reasons was 0 days (IQR 0–12.3) and 2.5 days (IQR 0–19), respectively. The WAI score (regression coefficient=−4.66 (p<0.001, CI −6.1 to −3.2), ‘getting a disability pension’ (regression coefficient=−106.8 (p<0.001, 95% CI −141.6 to −72.0) and other not significant variables explained 70% of the variance in absence days (p<0.001), and therefore may estimate the number of absence days. Conclusions Absences in our sample of AS patients were equal to pan-European countries. In groups of AS patients, the WAI and other variables are valid to estimate absence days with the help of a two-part regression model. PMID:23524041

  1. Functional and technological potential of dehydrated Phaseolus vulgaris L. flours.

    PubMed

    Ramírez-Jiménez, A K; Reynoso-Camacho, R; Mendoza-Díaz, S; Loarca-Piña, G

    2014-10-15

    The effect of cooking followed by dehydration was evaluated on the bioactive composition, antioxidant activity and technological properties of two varieties (Negro 8025 and Bayo Madero) of common beans. Quercetin, rutin, and phenolic acids were the most abundant phenolics found. Cooking processes resulted in decreased values of some phenolic compounds and antioxidant capacity. A subsequent dehydration increased TEAC values, resistant starch content and decreased starch digestibility. Oligosaccharides and dietary fibre were preserved in both treatments. Variety had a strong impact on phytochemical profile, being Negro 8025 that exhibited the highest content of most of the compounds assessed. Water absorption index (WAI) and oil absorption capacity (OAC) were determined in order to measure technological suitability. Dehydration produced flours with stable WAI and low oil pick up. The results suggest that the flours of Negro 8025 beans have a good potential to be considered as functional ingredient for healthy food products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Changes in the functional properties and antinutritional factors of extruded hard-to-cook common beans (Phaseolus vulgaris, L.).

    PubMed

    Batista, Karla A; Prudêncio, Sandra H; Fernandes, Kátia F

    2010-04-01

    The biochemical and functional properties of 2 hard-to-cook common bean cultivars (Phaseolus vulgaris, L.) were investigated after the extrusion process. Beans of BRS pontal and BRS grafite cultivars were milled and extruded at 150 degrees C, with a compression ratio screw of 3 : 1, 5-mm die, and screw speed of 150 rpm. Extrudate flours were evaluated for water solubility (WS), water absorption index (WAI), oil absorption capacity (OAC), foaming capacity (FC), emulsifying activity (EA), antinutritional factors, and in vitro protein and starch digestibility. Results indicated that the extrusion significantly decreased antinutrients such as phytic acid, lectin, alpha-amylase, and trypsin inhibitors, reduced the emulsifying capacity and eliminated the FC in both BRS pontal and BRS grafite cultivars. In addition, the WS, WAI, and in vitro protein and starch digestibility were improved by the extrusion process. These results indicate that it is possible to produce new extruded products with good functional and biochemical properties from these common bean cultivars.

  3. Effects of work-related stress on work ability index among refinery workers

    PubMed Central

    Habibi, Ehsanollah; Dehghan, Habibollah; Safari, Shahram; Mahaki, Behzad; Hassanzadeh, Akbar

    2014-01-01

    Introduction: Work-related stress is one of the basic problems in industrial also top 10 work-related health problems and it is increasingly implicated in the development a number of problems such as cardiovascular disease, musculoskeletal diseases, early retirement to employees. On the other hand, early retirement to employees from the workplace has increased on the problems of today's industries. Hereof, improving work ability is one of the most effective ways to enhance the ability and preventing disability and early retirement. The aim of This study is determine the relationship between job stress score and work ability index (WAI) at the refinery workers. Materials and Methods: This is a cross-sectional study in which 171 workers from a refinery in isfahan in 2012 who were working in different occupational groups participated. Based on appropriate assignment sampling, 33 office workers, 69 operational workers, and 69 maintenance workers, respectively, were invited to participate in this study. Two questionnaires including work related-stress and WAI were filled in. Finally, the information was analyzed using the SPSS-20 and statistic tests namely, analysis of covariance Kruskal-Wallis test. Pearson correlation coefficient, ANOVA and t-test. Results: Data analysis revealed that 86% and 14% of participants had moderate and severe stress respectively. Average score of stress and standard deviation was 158.7 ± 17.3 that was in extreme stress range. Average score and standard deviation of WAI questionnaire were 37.18 and 3.86 respectively. That placed in a good range. Pearson correlation coefficient showed that WAI score had significant reversed relationship with a score of stress. Conclusion: According to the results, mean stress score among refinery worker was high and one fator that affect work abiity was high stress, hence training on communication skills and safe working environment in order to decreses stress, enhance the work ability of workers. PMID

  4. Effects of work-related stress on work ability index among refinery workers.

    PubMed

    Habibi, Ehsanollah; Dehghan, Habibollah; Safari, Shahram; Mahaki, Behzad; Hassanzadeh, Akbar

    2014-01-01

    Work-related stress is one of the basic problems in industrial also top 10 work-related health problems and it is increasingly implicated in the development a number of problems such as cardiovascular disease, musculoskeletal diseases, early retirement to employees. On the other hand, early retirement to employees from the workplace has increased on the problems of today's industries. Hereof, improving work ability is one of the most effective ways to enhance the ability and preventing disability and early retirement. The aim of This study is determine the relationship between job stress score and work ability index (WAI) at the refinery workers. This is a cross-sectional study in which 171 workers from a refinery in isfahan in 2012 who were working in different occupational groups participated. Based on appropriate assignment sampling, 33 office workers, 69 operational workers, and 69 maintenance workers, respectively, were invited to participate in this study. Two questionnaires including work related-stress and WAI were filled in. Finally, the information was analyzed using the SPSS-20 and statistic tests namely, analysis of covariance Kruskal-Wallis test. Pearson correlation coefficient, ANOVA and t-test. Data analysis revealed that 86% and 14% of participants had moderate and severe stress respectively. Average score of stress and standard deviation was 158.7 ± 17.3 that was in extreme stress range. Average score and standard deviation of WAI questionnaire were 37.18 and 3.86 respectively. That placed in a good range. Pearson correlation coefficient showed that WAI score had significant reversed relationship with a score of stress. According to the results, mean stress score among refinery worker was high and one fator that affect work abiity was high stress, hence training on communication skills and safe working environment in order to decreses stress, enhance the work ability of workers.

  5. Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

    PubMed Central

    Gill, Balmeet Singh

    2014-01-01

    Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure. PMID:26904639

  6. Comparison of the K-BIT with Short Forms of the WAIS-R in a Neuropsychological Population.

    ERIC Educational Resources Information Center

    Eisenstein, Norman; Engelhart, Charles I.

    1997-01-01

    The Kaufman Brief Intelligence Test (K-BIT) (A. S. Kaufman and N. L. Kaufman, 1990) was compared with short forms of the Wechsler Adult Intelligence Scale--Revised (WAIS-R) using results from 64 referrals to a neuropsychology service. Advantages of each test are noted and their use discussed. (SLD)

  7. Cold pressor-induced pain does not impair WAIS-IV processing speed index or working memory index performance.

    PubMed

    Etherton, Joseph

    2014-01-01

    Chronic pain frequently involves cognitive complaints such as concentration and memory deficits, but studies of the effects of pain on cognition have not consistently demonstrated deficits and have not typically utilized standard neuropsychological instruments. Effects of cold pressor-induced pain on Wechsler Adult Intelligence Scale-Fourth Edition Processing Speed Index (PSI) and Working Memory Index (WMI) performance was examined in nonclinical volunteers (n = 40). All took one PSI subtest and one WMI subtest normally, and then took different PSI and WMI subtests during cold pressor-induced pain or painless warm-water immersion. Scaled scores for normal administration versus pain or painless water immersion did not differ and there was no interaction between group (control vs. pain) and manner of administration, despite moderately severe mean pain ratings (M = 6.8 on a 0-10 pain-rating scale). Results indicate that induced pain in nonclinical volunteers does not impair PSI or WMI performance, and they suggest that chronic pain per se should not be expected to substantially affect these cognitive functions. However, patients with chronic pain may differ from nonclinical volunteers in their experience of pain, potentially limiting generalizability.

  8. The Distribution of Scaled Scores and Possible Floor Effects on the WISC-III and WAIS-III

    ERIC Educational Resources Information Center

    Whitaker, Simon; Wood, Christopher

    2008-01-01

    Objective: It has been suggested that, as the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) give a scaled score of one even if a client scores a raw score of zero, these assessments may have a hidden floor effect at low IQ levels. The study looked for…

  9. The National Adult Reading Test: restandardisation against the Wechsler Adult Intelligence Scale-Fourth edition.

    PubMed

    Bright, Peter; Hale, Emily; Gooch, Vikki Jayne; Myhill, Thomas; van der Linde, Ian

    2018-09-01

    Since publication in 1982, the 50-item National Adult Reading Test (NART; Nelson, 1982; NART-R; Nelson & Willison, 1991) has remained a widely adopted method for estimating premorbid intelligence both for clinical and research purposes. However, the NART has not been standardised against the most recent revisions of the Wechsler Adult Intelligence Scale (WAIS-III; Wechsler, 1997, and WAIS-IV; Wechsler, 2008). Our objective, therefore, was to produce reliable standardised estimates of WAIS-IV IQ from the NART. Ninety-two neurologically healthy British adults were assessed and regression equations calculated to produce population estimates of WAIS-IV full-scale IQ (FSIQ) and constituent index scores. Results showed strong NART/WAIS-IV FSIQ correlations with more moderate correlations observed between NART error and constituent index scores. FSIQ estimates were closely similar to the published WAIS and WAIS-R estimates at the high end of the distribution, but at the lower end were approximately equidistant from the highly discrepant WAIS (low) and WAIS-R (high) values. We conclude that the NART is likely to remain an important tool for estimating the impact of neurological damage on general cognitive ability. We advise caution in the use of older published WAIS and/or WAIS-R estimates for estimating premorbid WAIS-IV FSIQ, particularly for those with low NART scores.

  10. Exploratory and Higher-Order Factor Analyses of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) Adolescent Subsample

    ERIC Educational Resources Information Center

    Canivez, Gary L.; Watkins, Marley W.

    2010-01-01

    The factor structure of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008a) with the adolescent participants (ages 16-19 years; N = 400) in the standardization sample was assessed using exploratory factor analysis, multiple factor extraction criteria, and higher-order exploratory factor analyses. Results from…

  11. Malingering in Toxic Exposure. Classification Accuracy of Reliable Digit Span and WAIS-III Digit Span Scaled Scores

    ERIC Educational Resources Information Center

    Greve, Kevin W.; Springer, Steven; Bianchini, Kevin J.; Black, F. William; Heinly, Matthew T.; Love, Jeffrey M.; Swift, Douglas A.; Ciota, Megan A.

    2007-01-01

    This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons…

  12. NONLINEAR COLOR-METALLICITY RELATIONS OF GLOBULAR CLUSTERS. V. NONLINEAR ABSORPTION-LINE INDEX VERSUS METALLICITY RELATIONS AND BIMODAL INDEX DISTRIBUTIONS OF M31 GLOBULAR CLUSTERS

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

    Kim, Sooyoung; Yoon, Suk-Jin; Chung, Chul

    2013-05-10

    Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Such division of extragalactic GCs, so far asserted mainly by photometric color bimodality, has been viewed as the presence of merely two distinct metallicity subgroups within individual galaxies and forms a critical backbone of various galaxy formation theories. Given that spectroscopy is a more detailed probe into stellar population than photometry, the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy ofmore » M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We take this as a close analogy to the recent view that metallicity-color nonlinearity is primarily responsible for observed GC color bimodality. We also demonstrate that the metallicity-sensitive magnesium line displays non-negligible metallicity-index nonlinearity and Balmer lines show rather strong nonlinearity. This gives rise to bimodal index distributions, which are routinely interpreted as bimodal metallicity distributions, not considering metallicity-index nonlinearity. Our findings give a new insight into the constitution of M31's GC system, which could change much of the current thought on the formation of GC systems and their host galaxies.« less

  13. Polarization-dependent optical absorption of MoS₂ for refractive index sensing.

    PubMed

    Tan, Yang; He, Ruiyun; Cheng, Chen; Wang, Dong; Chen, Yanxue; Chen, Feng

    2014-12-17

    As a noncentrosymmetric crystal with spin-polarized band structure, MoS2 nanomaterials have attracts increasing attention in many areas such as lithium ion batteries, flexible electronic devices, photoluminescence and valleytronics. The investigation of MoS2 is mainly focused on the electronics and spintronics instead of optics, which restrict its applications as key elements of photonics. In this work, we demonstrate the first observation of the polarization-dependent optical absorption of the MoS2 thin film, which is integrated onto an optical waveguide device. With this feature, a novel optical sensor combining MoS2 thin-film and a microfluidic structure has been constituted to achieve the sensitive monitoring of refractive index. Our work indicates the MoS2 thin film as a complementary material to graphene for the optical polarizer in the visible light range, and explores a new application direction of MoS2 nanomaterials for the construction of photonic circuits.

  14. Decrease in Work Ability Index and sickness absence during the following year: a two-year follow-up study.

    PubMed

    Ohta, Masanori; Higuchi, Yoshiyuki; Kumashiro, Masaharu; Yamato, Hiroshi; Sugimura, Hisamichi

    2017-11-01

    Using a 2-year follow-up design, we examined whether changes in work ability during 1 year predicted sickness absence in the following year. Workers (N = 1408) from the Japanese information technology sector each completed the Work Ability Index (WAI), the Brief Job Stress Questionnaire (BJSQ), and the General Health Questionnaire (GHQ) in 2011 and 2012. Absence data during 2013 was obtained from employees' computerized attendance records. We used psychological distress as evaluated by the GHQ; job stress and job support calculated using the BJSQ; and job title, sex, and age as potential confounding variables. Thirty-five employees had at least one sickness absence lasting more than seven consecutive days in 2013. Forty-nine percent of sickness absences were due to mental illness, and the others were due to orthopedic disease (20%), cancer (9%), and other illnesses (23%). Decrease in WAI scores from 2011 to 2012 predicted sickness absence in 2013 (Odds ratio (OR) 1.19, 95% confidence interval (CI) 1.12-1.27). This association remained unaltered after adjusting for sex, age, job title, WAI score from the year before, job stress, job support, and GHQ score (OR 1.15, 95% CI 1.06-1.25). We analyzed this association separately by reason for absence: mental or other illness. WAI score decreases predicted sickness absence for both reasons (OR for mental illness 1.24, 95% CI 1.14-1.36; OR for other illnesses 1.14, 95% CI 1.04-1.24). Decrease in work ability during the year predicts sickness absence in the following year while predictive power was weak.

  15. Accurate and facile determination of the index of refraction of organic thin films near the carbon 1s absorption edge.

    PubMed

    Yan, Hongping; Wang, Cheng; McCarn, Allison R; Ade, Harald

    2013-04-26

    A practical and accurate method to obtain the index of refraction, especially the decrement δ, across the carbon 1s absorption edge is demonstrated. The combination of absorption spectra scaled to the Henke atomic scattering factor database, the use of the doubly subtractive Kramers-Kronig relations, and high precision specular reflectivity measurements from thin films allow the notoriously difficult-to-measure δ to be determined with high accuracy. No independent knowledge of the film thickness or density is required. High confidence interpolation between relatively sparse measurements of δ across an absorption edge is achieved. Accurate optical constants determined by this method are expected to greatly improve the simulation and interpretation of resonant soft x-ray scattering and reflectivity data. The method is demonstrated using poly(methyl methacrylate) and should be extendable to all organic materials.

  16. Linear and nonlinear magneto-optical absorption coefficients and refractive index changes in graphene

    NASA Astrophysics Data System (ADS)

    Nguyen, Chuong V.; Hieu, Nguyen N.; Duque, Carlos A.; Poklonski, Nikolai A.; Ilyasov, Victor V.; Hieu, Nguyen V.; Dinh, Le; Quang, Quach K.; Tung, Luong V.; Phuc, Huynh V.

    2017-07-01

    In this work, we study the magneto-optical absorption coefficients (MOACs) and refractive index changes (RICs) in monolayer graphene under a perpendicular magnetic field using the compact density matrix approach. The results are presented as functions of photon energy and external magnetic field. Our results show that there are three groups of the possible transitions: the intra-band, the mixed, and the inter-band transitions; in which the MOACs and the RICs appear as a series of peaks in both intra-band and inter-band transitions between the Landau levels. With an increase magnetic field, the resonant peaks give a blue-shift and reduce in their amplitudes. These results suggest a potential application of monolayer graphene in nanoscale electronic and magneto-optical devices.

  17. Orthogonal Higher Order Structure and Confirmatory Factor Analysis of the French Wechsler Adult Intelligence Scale (WAIS-III)

    ERIC Educational Resources Information Center

    Golay, Philippe; Lecerf, Thierry

    2011-01-01

    According to the most widely accepted Cattell-Horn-Carroll (CHC) model of intelligence measurement, each subtest score of the Wechsler Intelligence Scale for Adults (3rd ed.; WAIS-III) should reflect both 1st- and 2nd-order factors (i.e., 4 or 5 broad abilities and 1 general factor). To disentangle the contribution of each factor, we applied a…

  18. Incidence of the WAIS-R Fuld profile in HIV-1 infection.

    PubMed

    van Gorp, W G; Tulin, S J; Evans, G; Satz, P

    1990-10-01

    The incidence of a WAIS-R subtest "marker" sensitive to cholinergic dysfunction was assessed in a sample 116 homosexual males infected with HIV (Acquired Immunodeficiency Syndrome [AIDS] N = 40; AIDS Related Complex [ARC], N = 76). The incidence of positive profiles was low in the overall sample (11/116, 9%), and significantly lower than incidence rates reported for known cholinergic deficient groups (Alzheimer's disease; scopolamine). However, significantly more AIDS patients (8/40, 20%) than ARC patients (3/76, 4%) demonstrated positive profiles. These results suggest that, as a group, persons with ARC or AIDS do not show an increased incidence of the Fuld profile associated with cholinergic disruption, and offer continued support for diagnostic specificity of the Fuld formula for Alzheimer's disease.

  19. Physical properties of extruded products from three Mexican common beans (Phaseolus vulgaris L.) cultivars.

    PubMed

    Rocha-Guzman, N E; Gallegos-Infante, J A; Gonzalez-Laredo, R F; Bello-Perez, A; Delgado-Licon, E; Ochoa-Martinez, A; Prado-Ortiz, M J

    2008-09-01

    The physical properties of extruded products from three Mexican common bean cultivars were investigated. Common bean cultivars Flor de Mayo, Pinto Villa and Bayo Victoria from the same harvesting season (2006) were used in this work. Beans were milled and the flour was hydrated to 24, 26 and 28 g of water/100 g of dry weight. Two temperatures, 130 degrees C and 165 degrees C at the end of the extruder barrel without die, were experimented. Common bean flour extrudates were evaluated for water absorption index (WAI), water absorption capacity (WAC), oil absorption capacity (OAC), and emulsifying capacity (EC). Flor de Mayo extrudates showed the highest WAC and WAI values. Thus starch from Flor de Mayo beans showed minor restricted water availability. In all cases, the OAC of extruded products was lower than the crude bean flour. The EC for Bayo Victoria flour increased as a consequence of the extrusion process. The EC for Flor de Mayo was higher at lower temperature and lower moisture content than Pinto Villa and Bayo Victoria beans. EC behavior of Pinto Villa was similar to Bayo cultivar. These results indicate that it is possible to produce new extruded products with good physical properties from these common bean cultivars.

  20. Late-Holocene climate evolution at the WAIS Divide site, West Antarctica: Bubble number-density estimates

    USGS Publications Warehouse

    Fegyveresi, John M.; Alley, R.B.; Spencer, M.K.; Fitzpatrick, J.J.; Steig, E.J.; White, J.W.C.; McConnell, J.R.; Taylor, K.C.

    2011-01-01

    A surface cooling of ???1.7??C occurred over the ???two millennia prior to ???1700 CE at the West Antarctic ice sheet (WAIS) Divide site, based on trends in observed bubble number-density of samples from the WDC06A ice core, and on an independently constructed accumulation-rate history using annual-layer dating corrected for density variations and thinning from ice flow. Density increase and grain growth in polar firn are both controlled by temperature and accumulation rate, and the integrated effects are recorded in the number-density of bubbles as the firn changes to ice. Numberdensity is conserved in bubbly ice following pore close-off, allowing reconstruction of either paleotemperature or paleo-accumulation rate if the other is known. A quantitative late-Holocene paleoclimate reconstruction is presented for West Antarctica using data obtained from the WAIS Divide WDC06A ice core and a steady-state bubble number-density model. The resultant temperature history agrees closely with independent reconstructions based on stable-isotopic ratios of ice. The ???1.7??C cooling trend observed is consistent with a decrease in Antarctic summer duration from changing orbital obliquity, although it remains possible that elevation change at the site contributed part of the signal. Accumulation rate and temperature dropped together, broadly consistent with control by saturation vapor pressure.

  1. Influence of image charge effect on impurity-related optical absorption coefficients and refractive index changes in a spherical quantum dot

    NASA Astrophysics Data System (ADS)

    Vartanian, A. L.; Asatryan, A. L.; Vardanyan, L. A.

    2017-03-01

    We have investigated the influence of an image charge effect (ICE) on the energies of the ground and first few excited states of a hydrogen-like impurity in a spherical quantum dot (QD) in the presence of an external electric field. The oscillator strengths of transitions from the 1 s -like state to excited states of 2px and 2pz symmetries are calculated as the functions of the strengths of the confinement potential and the electric field. Also, we have studied the effect of image charges on linear and third-order nonlinear optical absorption coefficients and refractive index changes (RICs). The results show that image charges lead to the decrease of energies for all the hydrogen-like states, to the significant enhancement of the oscillator strengths of transitions between the impurity states, and to comparatively large blue shifts in linear, nonlinear, and total absorption coefficients and refractive index changes. Our results indicate that the total optical characteristics can be controlled by the strength of the confinement and the electric field.

  2. The reliability of multidimensional neuropsychological measures: from alpha to omega.

    PubMed

    Watkins, Marley W

    To demonstrate that Coefficient omega, a model-based estimate, is more a more appropriate index of reliability than coefficient alpha for the multidimensional scales that are commonly employed by neuropsychologists. As an illustration, a structural model of an overarching general factor and four first-order factors for the WAIS-IV based on the standardization sample of 2200 participants was identified and omega coefficients were subsequently computed for WAIS-IV composite scores. Alpha coefficients were ≥ .90 and omega coefficients ranged from .75 to .88 for WAIS-IV factor index scores, indicating that the blend of general and group factor variance in each index score created a reliable multidimensional composite. However, the amalgam of variance from general and group factors did not allow the precision of Full Scale IQ (FSIQ) and factor index scores to be disentangled. In contrast, omega hierarchical coefficients were low for all four factor index scores (.10-.41), indicating that most of the reliable variance of each factor index score was due to the general intelligence factor. In contrast, the omega hierarchical coefficient for the FSIQ score was .84. Meaningful interpretation of WAIS-IV factor index scores as unambiguous indicators of group factors is imprecise, thereby fostering unreliable identification of neurocognitive strengths and weaknesses, whereas the WAIS-IV FSIQ score can be interpreted as a reliable measure of general intelligence. It was concluded that neuropsychologists should base their clinical decisions on reliable scores as indexed by coefficient omega.

  3. Energy absorption during impact on the proximal femur is affected by body mass index and flooring surface.

    PubMed

    Bhan, Shivam; Levine, Iris C; Laing, Andrew C

    2014-07-18

    Impact mechanics theory suggests that peak loads should decrease with increase in system energy absorption. In light of the reduced hip fracture risk for persons with high body mass index (BMI) and for falls on soft surfaces, the purpose of this study was to characterize the effects of participant BMI, gender, and flooring surface on system energy absorption during lateral falls on the hip with human volunteers. Twenty university-aged participants completed the study with five men and five women in both low BMI (<22.5 kg/m(2)) and high BMI (>27.5 kg/m(2)) groups. Participants underwent lateral pelvis release experiments from a height of 5 cm onto two common floors and four safety floors mounted on a force plate. A motion-capture system measured pelvic deflection. The energy absorbed during the initial compressive phase of impact was calculated as the area under the force-deflection curve. System energy absorption was (on average) 3-fold greater for high compared to low BMI participants, but no effects of gender were observed. Even after normalizing for body mass, high BMI participants absorbed 1.8-fold more energy per unit mass. Additionally, three of four safety floors demonstrated significantly increased energy absorption compared to a baseline resilient-rolled-sheeting system (% increases ranging from 20.7 to 28.3). Peak system deflection was larger for high BMI persons and for impacts on several safety floors. This study indicates that energy absorption may be a common mechanism underlying the reduced risk of hip fracture for persons with high BMI and for those who fall on soft surfaces. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  4. Polarization-dependent optical absorption of MoS2 for refractive index sensing

    PubMed Central

    Tan, Yang; He, Ruiyun; Cheng, Chen; Wang, Dong; Chen, Yanxue; Chen, Feng

    2014-01-01

    As a noncentrosymmetric crystal with spin-polarized band structure, MoS2 nanomaterials have attracts increasing attention in many areas such as lithium ion batteries, flexible electronic devices, photoluminescence and valleytronics. The investigation of MoS2 is mainly focused on the electronics and spintronics instead of optics, which restrict its applications as key elements of photonics. In this work, we demonstrate the first observation of the polarization-dependent optical absorption of the MoS2 thin film, which is integrated onto an optical waveguide device. With this feature, a novel optical sensor combining MoS2 thin-film and a microfluidic structure has been constituted to achieve the sensitive monitoring of refractive index. Our work indicates the MoS2 thin film as a complementary material to graphene for the optical polarizer in the visible light range, and explores a new application direction of MoS2 nanomaterials for the construction of photonic circuits. PMID:25516116

  5. [Assessment of work ability index in evaluation of small peptides geroprotective effect].

    PubMed

    Bashkireva, A S; Kachan, E Yu

    We have conducted a comparative analysis of the work ability index (WAI) application in evaluation of the effectiveness of small peptides (cytogens) used as geroprotectors in the system of preventive medical nutrition of those working with occupational hazards. Our study revealed the necessity of an inclusion of small peptides into the system of preventive medical nutrition, health promotion in people working with occupational hazards and thus subjected to an accelerated aging. The combined application of peptide geroprotectors makes it possible to restore and enhance adaptive resources as well as to correct work ability and maintain health and well-being in different professional groups.

  6. Absorption coefficient and relative refractive index change for a double δ-doped GaAs MIGFET-like structure: Electric and magnetic field effects

    NASA Astrophysics Data System (ADS)

    Martínez-Orozco, J. C.; Rodríguez-Magdaleno, K. A.; Suárez-López, J. R.; Duque, C. A.; Restrepo, R. L.

    2016-04-01

    In this work we present theoretical results for the electronic structure as well as for the absorption coefficient and relative refractive index change for an asymmetric double δ-doped like confining potential in the active region of a Multiple Independent Gate Field Effect Transistor (MIGFET) system. We model the potential profile as a double δ-doped like potential profile between two Schottky (parabolic) potential barriers that are just the main characteristics of the MIGFET configuration. We investigate the effect of external electromagnetic fields in this kind of quantum structures, in particular we applied a homogeneous constant electric field in the growth direction z as well as a homogeneous constant magnetic field in the x-direction. In general we conclude that by applying electromagnetic fields we can modulate the resonant peaks of the absorption coefficient as well as their energy position. Also with such probes it is possible to control the nodes and amplitude of the relative refractive index changes related to resonant intersubband optical transitions.

  7. Investigation of process and product parameters for physicochemical properties of rice and mung bean (Vigna radiata) flour based extruded snacks.

    PubMed

    Sharma, Chetan; Singh, Baljit; Hussain, Syed Zameer; Sharma, Savita

    2017-05-01

    PR 106 and SML 668 cultivars of rice and mung bean respectively, were studied for their potential to serve as a nutritious snack with improved protein quality and quantity. The effect of extrusion conditions, including feed moisture content (14-18%), screw speed (400-550 rpm) and barrel temperature (130-170°C) on the physicochemical properties (bulk density, water absorption index (WAI), water solubility index (WSI) and hardness) was investigated. The replacement of rice flour at 30% level with mung bean flour for making extruded snacks was evaluated. Pasting temperature increased (84-93 °C) while peak viscosity (2768-408 cP), hold viscosity (2018-369 cP), breakdown (750-39 cP), setback (2697-622 cP) and final viscosity (4715-991 cP) decreased with increasing mung bean flour addition. Increasing feed moisture lowered the specific mechanical energy (SME), WAI and WSI of extrudates whereas increased bulk density and hardness. Higher screw speed had linear positive effect on SME of extruder and negative linear effect on WAI. Positive curvilinear quadratic effect of screw speed was also observed on WSI and density. Higher barrel temperature linearly decreased the SME, density and hardness of extrudates. Developed extrusion cooked rice-mung bean snacks with increased protein content and improved protein quality along with higher dietary fibre and minerals have good potential in effectively delivering the nutrition to the population.

  8. Negative induced absorption and negative index of refraction for iron doped potash-alumina-borate glasses subjected to thermal-radiation treatment

    NASA Astrophysics Data System (ADS)

    Salakhitdinov, Amritdin; Ibragimova, Elvira; Salakhitdinova, Maysara

    2018-02-01

    This work experimentally revealed, that 60Co-gamma-irradiation of potash-alumina-borate glasses doped with 1 and 2 mass% of iron oxide to the dose of 1.7 MR in the temperature range of 150-300 °C induced differential optical density changes within - 6 ≤ Δ D ≤ 0 in the wave length range of 300-350 nm, which is characteristic for meta-material. Calculations have shown that variation of optical refraction index within - 0.05 ≤ Δ n ω ≤ 0.05 due to microstructure transformation causes changes in the differential absorption index of the glass - 0.5 < Δ α ω < 0.55.

  9. Self-Referenced Method for Estimating Refractive Index and Absolute Absorption of Loose Semiconductor Powders

    DOE PAGES

    Huang, Huafeng; Colabello, Diane M.; Sklute, Elizabeth C.; ...

    2017-04-23

    The absolute absorption coefficient, α(E), is a critical design parameter for devices using semiconductors for light harvesting associated with renewable energy production, both for classic technologies such as photovoltaics and for emerging technologies such as direct solar fuel production. While α(E) is well-known for many classic simple semiconductors used in photovoltaic applications, the absolute values of α(E) are typically unknown for the complex semiconductors being explored for solar fuel production due to the absence of single crystals or crystalline epitaxial films that are needed for conventional methods of determining α(E). In this work, a simple self-referenced method for estimating bothmore » the refractive indices, n(E), and absolute absorption coefficients, α(E), for loose powder samples using diffuse reflectance data is demonstrated. In this method, the sample refractive index can be deduced by refining n to maximize the agreement between the relative absorption spectrum calculated from bidirectional reflectance data (calculated through a Hapke transform which depends on n) and integrating sphere diffuse reflectance data (calculated through a Kubleka–Munk transform which does not depend on n). This new method can be quickly used to screen the suitability of emerging semiconductor systems for light-harvesting applications. The effectiveness of this approach is tested using the simple classic semiconductors Ge and Fe 2O 3 as well as the complex semiconductors La 2MoO 5 and La 4Mo 2O 11. The method is shown to work well for powders with a narrow size distribution (exemplified by Fe 2O 3) and to be ineffective for semiconductors with a broad size distribution (exemplified by Ge). As such, it provides a means for rapidly estimating the absolute optical properties of complex solids which are only available as loose powders.« less

  10. Physical properties of the WAIS Divide ice core

    USGS Publications Warehouse

    Fitzpatrick, Joan J.; Voigt, Donald E.; Fegyveresi, John M.; Stevens, Nathan T.; Spencer, Matthew K.; Cole-Dai, Jihong; Alley, Richard B.; Jardine, Gabriella E.; Cravens, Eric; Wilen, Lawrence A.; Fudge, T. J.; McConnell, Joseph R.

    2014-01-01

    The WAIS (West Antarctic Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending ∼50 m above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity. The climate record developed from this core is therefore likely to be continuous and robust. Measured grain-growth rates, recrystallization characteristics, and grain-size response at climate transitions fit within current understanding. Significant impurity control on grain size is indicated from correlation analysis between impurity loading and grain size. Bubble-number densities and bubble sizes and shapes are presented through the full extent of the bubbly ice. Where bubble elongation is observed, the direction of elongation is preferentially parallel to the trace of the basal (0001) plane. Preferred crystallographic orientation of grains is present in the shallowest samples measured, and increases with depth, progressing to a vertical-girdle pattern that tightens to a vertical single-maximum fabric. This single-maximum fabric switches into multiple maxima as the grain size increases rapidly in the deepest, warmest ice. A strong dependence of the fabric on the impurity-mediated grain size is apparent in the deepest samples.

  11. A comparison of low IQ scores from the Reynolds Intellectual Assessment Scales and the Wechsler Adult Intelligence Scale-Third Edition.

    PubMed

    Umphress, Thomas B

    2008-06-01

    Twenty people with suspected intellectual disability took the Reynolds Intellectual Assessment Scales (RIAS; C. R. Reynolds & R. W. Kamphaus, 1998) and the Wechsler Adult Intelligence Scale-3rd Edition (WAIS-III; D. Wechsler, 1997) to see if the 2 IQ tests produced comparable results. A t test showed that the RIAS Composite Intelligence Index scores were significantly higher than WAIS-III Full Scale IQ scores at the alpha level of .01. There was a significant difference between the RIAS Nonverbal Intelligence and WAIS-III Performance Scale, but there was no significant difference between the RIAS Verbal Intelligence Index and the WAIS-III Verbal Scale IQ. The results raise questions concerning test selection for diagnosing intellectual disability and the use of the correlation statistic for comparing intelligence tests.

  12. Changes in the Thermohaline Flow due to changes in the WAIS and Astronomical Forcing during the MIS31 Superinterglacial

    NASA Astrophysics Data System (ADS)

    Justino, F. J.; Lindemann, D.; Kucharski, F.; Wilson, A.; Bromwich, D. H.; Stordal, F.

    2017-12-01

    The Marine Isotope Stage 31 (MIS31, between 1085 ka and 1055 ka) was characterised by higher extra-tropical air temperatures and a substantial recession of polar glaciers compared to today. Paleoreconstructions and model simulations have increased the understanding of the MIS31 interval, but questions remain regarding the role of the Atlantic and Pacific Oceans in modifying the climate associated with the variations in Earth's orbital parameters. Multi-century coupled climate simulations, with the astronomical configuration of the MIS31 and modified West Antarctic Ice Sheet (WAIS) topography, show an increase in the thermohaline flux and northward oceanic heat transport (OHT) in the Pacific Ocean. These oceanic changes are driven by anomalous atmospheric circulation and increased surface salinity in concert with a stronger meridional overturning circulation (MOC). The intensified northward OHT is responsible for up to 85% of the global OHT anomalies and contributes to the overall reduction in sea-ice in the Northern Hemisphere (NH) due to Earth's astronomical configuration. The relative contributions of the Atlantic Ocean to global OHT and MOC anomalies are minor compared to that of the Pacific. However, sea-ice changes are remarkable, highlighted by decreased (increased) cover in Ross (Weddell) Sea but widespread reductions of sea-ice across the NH. These modeling results have enormous implications for paleoreconstructions of the MIS31 climate that mostly assume overall ice free conditions in the vicinity of the Antarctic continent. Since these reconstructions may depict dominant signals in a particular time interval and locale, they cannot be assumed to geographically represent large-scale domains. Therefore, their ability to reproduce long-term environmental conditions should be considered with care. Finally, it is important to emphasize that understanding past interglacial intervals that are characterized by a depleted WAIS can shed light on the potential

  13. Absorption Spectra of Gold Nanoparticle Suspensions

    NASA Astrophysics Data System (ADS)

    Anan'eva, M. V.; Nurmukhametov, D. R.; Zverev, A. S.; Nelyubina, N. V.; Zvekov, A. A.; Russakov, D. M.; Kalenskii, A. V.; Eremenko, A. N.

    2018-02-01

    Three gold nanoparticle suspensions are obtained, and mean radii in distributions - (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm - are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450-800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie-Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

  14. Determination of the ground albedo and the index of absorption of atmospheric particulates by remote sensing. II - Application

    NASA Technical Reports Server (NTRS)

    King, M. D.

    1979-01-01

    A hemispherical radiometer has been used to obtain spectrally narrow-band measurements of the downward hemispheric diffuse and total (global) flux densities at varying solar zenith angles on 14 days over Tucson. Data are presented which illustrate the effects of temporally varying atmospheric conditions as well as clear stable conditions on the ratio of the diffuse to direct solar radiation at the earth's surface. The ground albedo and the effective imaginary term of the complex refractive index of atmospheric particulates are derived from the diffuse-direct ratio measurements on seven clear stable days at two wavelengths using the statistical procedure described by King and Herman (1979). Results indicate that the downwelling diffuse radiation field in the midvisible region in Tucson can be adequately described by Mie scattering theory if the ground albedo is 0.279 + or - 0.100 and the index of absorption is 0.0306 + or - 0.0082.

  15. The Utility of Seven-Subtest Short Forms of the Wechsler Adult Intelligence Scale-III in Young Adults

    ERIC Educational Resources Information Center

    Tam, Wai-Cheong Carl

    2004-01-01

    Along with ongoing research on the WAIS-R, short forms of the WAIS-III have attracted much attention. However, few studies of WAIS-III short forms are based on normal samples or on the validation of estimated indexes. This study examined the utility of two seven-subtest short forms in 81 healthy young adults in Taiwan with the administration of…

  16. Cognitive Profiles of Adults with Asperger's Disorder, High-Functioning Autism, and Pervasive Developmental Disorder Not Otherwise Specified Based on the WAIS-III

    ERIC Educational Resources Information Center

    Kanai, Chieko; Tani, Masayuki; Hashimoto, Ryuichiro; Yamada, Takashi; Ota, Haruhisa; Watanabe, Hiromi; Iwanami, Akira; Kato, Nobumasa

    2012-01-01

    Little is known about the cognitive profiles of high-functioning Pervasive Developmental Disorders (PDD) in adults based on the Wechsler Intelligence Scale III (WAIS-III). We examined cognitive profiles of adults with no intellectual disability (IQ greater than 70), and in adults with Asperger's disorder (AS; n = 47), high-functioning autism (HFA;…

  17. Discrepancies between bilinguals' performance on the Spanish and English versions of the WAIS Digit Span task: Cross-cultural implications.

    PubMed

    López, Enrique; Steiner, Alexander J; Hardy, David J; IsHak, Waguih W; Anderson, W Brantley

    2016-01-01

    This study explored within-subjects differences in the performance of 40 bilingual participants on the English and Spanish versions of the Wechsler Adult Intelligence Scale (WAIS) Digit Span task. To test the linguistic hypothesis that individuals would perform worse in Spanish because of its syllabic demand, we compared the number of syllables correctly recalled by each participant for every correct trial. Our analysis of the correct number of syllables remembered per trial showed that participants performed significantly better (i.e., recalling more syllables) in Spanish than in English on the total score. Findings suggest the Spanish version of the Digit Span (total score) was significantly more difficult than the English version utilizing traditional scoring methods. Moreover, the Forward Trial, rather than the Backward Trial, was more likely to show group differences between both language versions. Additionally, the Spanish trials of the Digit Span were correlated with language comprehension and verbal episodic memory measures, whereas the English trials of the Digit Span were correlated with confrontational naming and verbal fluency tasks. The results suggest that more research is necessary to further investigate other cognitive factors, rather than just syllabic demand, that might contribute to performance and outcome differences on the WAIS Digit Span in Spanish-English bilinguals.

  18. Determining the refractive index of human hemoglobin solutions by Kramers-Kronig relations with an improved absorption model.

    PubMed

    Gienger, Jonas; Groß, Hermann; Neukammer, Jörg; Bär, Markus

    2016-11-01

    The real part of the refractive index of aqueous solutions of human hemoglobin is computed from their absorption spectra in the wavelength range 250-1100 nm using the Kramers-Kronig (KK) relations, and the corresponding uncertainty analysis is provided. The strong ultraviolet (UV) and infrared absorbance of the water outside this spectral range were taken into account in a previous study employing KK relations. We improve these results by including the concentration dependence of the water absorbance as well as by modeling the deep UV absorbance of hemoglobin's peptide backbone. The two free parameters of the model for the deep UV absorbance are fixed by a global fit.

  19. Co-extrusion of food grains-banana pulp for nutritious snacks: optimization of process variables.

    PubMed

    Mridula, D; Sethi, Swati; Tushir, Surya; Bhadwal, Sheetal; Gupta, R K; Nanda, S K

    2017-08-01

    Present study was undertaken to optimize the process conditions for development of food grains (maize, defatted soy flour, sesame seed)-banana based nutritious expanded snacks using extrusion processing. Experiments were designed using Box-Behnken design with banana pulp (8-24 g), screw speed (300-350 rpm) and feed moisture (14-16% w.b.). Seven responses viz. expansion ratio (ER), bulk density (BD), water absorption index (WAI), protein, minerals, iron and sensory acceptability were considered for optimizing independent parameters. ER, BD, WAI, protein content, total minerals, iron content, and overall acceptability ranged 2.69-3.36, 153.43-238.83 kg/m 3 , 4.56-4.88 g/g, 15.19-15.52%, 2.06-2.27%, 4.39-4.67 mg/100 g (w.b.) and 6.76-7.36, respectively. ER was significantly affected by all three process variables while BD was influenced by banana pulp and screw speed only. Studied process variables did not affected colour quality except 'a' value with banana pulp and screw speed. Banana pulp had positive correlation with water solubility index, total minerals and iron content and negative with WAI, protein and overall acceptability. Based upon multiple response analysis, optimized conditions were 8 g banana pulp, 350 rpm screw speed and 14% feed moisture indicating the protein, calorie, iron content and overall sensory acceptability in sample as 15.46%, 401 kcal/100 g, 4.48 mg/100 g and 7.6 respectively.

  20. Reflections on work as done (WAD) and work as imagined (WAI) in an emergency response organization: A study on firefighters training exercises.

    PubMed

    Carvalho, Paulo Victor R de; Righi, Angela W; Huber, Gilbert J; Lemos, Caio de F; Jatoba, Alessandro; Gomes, José Orlando

    2018-04-01

    Emergency response organizations need to be resilient to cope with escalating events resulting from dynamic, unexpected, or complex situations. In Brazil, the Firefighter Corps are military hierarchal organizations with a culture based on fixed structures, well defined norms and procedures. These push against innovations which are necessary to be resilient. This research describes how firefighter captains in the 30-35-year age range managed an emergency response escalation in light of standard operating procedures (SOPs) during a training exercise. The study used ethnographic methods to find and discuss gaps between the instructions and the activities carried out during the exercise, highlighting the differences between work as done (WAD) and work as imagined (WAI), as it was instantiated in the SOP prescriptions. The aim was to produce reflections on WAI and WAD as a way to raise awareness of the need for a cultural change toward resilience in firefighter organizations. This was achieved through firefighter engagement with a comprehensive visualization of the analysis results which afforded easy interaction between the experts, the data, and the researchers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Physico-chemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate.

    PubMed

    Guzmán-Ortiz, Fabiola Araceli; Hernández-Sánchez, Humberto; Yee-Madeira, Hernani; San Martín-Martínez, Eduardo; Robles-Ramírez, María Del Carmen; Rojas-López, Marlon; Berríos, Jose De J; Mora-Escobedo, Rosalva

    2015-07-01

    A central composite design using RMS (Response Surface Methodology) successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality as expansion index (EI), water absorption index (WAI), water solubility index (WSI) and total color difference (ΔE) studied. The regression model indicated that EI, WAI, WSI and ΔE were significant (p < 0.05) with coefficients of determination (R(2)) of 0.7371, 0.7588, 0.7622, 0.8150, respectively. The optimized processing conditions were obtained with 25.8 % feed moisture, 160 °C die temperature and 58 %/42 % soybean/corn proportion. It was not found statistically changes in amino acid profile due to extrusion process. The electrophoretic profile of extruded soybean/corn mix presented low intensity molecular weight bands, compared to the unprocessed sample. The generation of low molecular weight polypeptides was associated to an increased in In vitro protein digestibility (IVPD) of the extrudate. The FTIR spectra of the soybean/corn mix before and after extrusion showed that the α-helix structure remained unchanged after extrusion. However, the band associated with β-sheet structure showed to be split into two bands at 1624 and 1640 cm(-1) . The changes in the β-sheet structures may be also associated to the increased in IVPD in the extruded sample.

  2. Effect of relaxation on working memory and the Bispectral Index of the EEG.

    PubMed

    Hudetz, Judith A; Hudetz, Anthony G; Reddy, Diane M

    2004-08-01

    Beneficial effects of relaxation on cardiovascular and immune functions and on memory has been implied but an empirical relationship between task performance and anxiety reduction has not been reported. In this study, we investigated whether guided imagery of relatively short duration would decrease S-Anxiety and electroencephalogram Bispectral Index and improve working memory. 42 participants (age: M=39, SD=11, 14 men, 28 women, university students and VA Medical Center employees, recruited by their professor or by fellow employees) underwent relaxation by 16-min. guided imagery or no treatment (control). Spielberger's State-Trait Anxiety Inventory and the WAIS-III Letter-Number Sequencing Test were administered before and after relaxation. S-Anxiety and BIS Index decreased and the Letter-Number test score increased by 30% after relaxation but not in the control group. This score was higher for participants with low anxiety and BIS Index. There was no significant difference between the groups before treatment. The results suggest that guided imagery of short duration produces relaxation as measured by psychological and neurophysiological indices and improves working memory performance.

  3. Multi-Group Covariance and Mean Structure Modeling of the Relationship between the WAIS-III Common Factors and Sex and Educational Attainment in Spain

    ERIC Educational Resources Information Center

    Dolan, Conor V.; Colom, Roberto; Abad, Francisco J.; Wicherts, Jelte M.; Hessen, David J.; van de Sluis, Sophie

    2006-01-01

    We investigated sex effects and the effects of educational attainment (EA) on the covariance structure of the WAIS-III in a subsample of the Spanish standardization data. We fitted both first order common factor models and second order common factor models. The latter include general intelligence ("g") as a second order common factor.…

  4. WAIS-IV and WISC-IV Structural Validity: Alternate Methods, Alternate Results. Commentary on Weiss et al. (2013a) and Weiss et al. (2013b)

    ERIC Educational Resources Information Center

    Canivez, Gary L.; Kush, Joseph C.

    2013-01-01

    Weiss, Keith, Zhu, and Chen (2013a) and Weiss, Keith, Zhu, and Chen (2013b), this issue, report examinations of the factor structure of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), respectively; comparing Wechsler Hierarchical Model (W-HM) and…

  5. Morphology, severity, and distribution of growth anomalies in the coral, Montipora capitata, at Wai`ōpae, Hawai`i

    NASA Astrophysics Data System (ADS)

    Burns, J. H. R.; Rozet, N. K.; Takabayashi, M.

    2011-09-01

    This study investigated the morphology, severity, and distribution of growth anomalies (GAs) in the coral, Montipora capitata, from Wai`ōpae tide pools, southeast Hawai`i Island. A macro-image analysis of skeletal microstructure placed GAs into two definable categories; Type A and Type B. Type A GAs had polyp density reduced by 43.05 ± 0.80% (mean ± SE) compared to healthy M. capitata tissue, with many fused and protrusive tuberculae. Type B GAs had no discernable polyps or calices and fused protuberant coenosteum. The prevalence of Type A and Type B GAs among all M. capitata colonies ( n = 1,093) in 8 tide pools at Wai`ōpae was 22.1% (range 2.8-33.7%) and 8.2% (range 0.0-16.9%), respectively. The proportion of colony surface area occupied by GA (relative GA cover) was quantified to assess the severity of this disease among all surveyed colonies. The relative GA cover was significantly greater on colonies larger than 1 m in diameter than smaller colonies and in the central portion of colonies than in the periphery. Furthermore, relative GA cover was negatively related to water motion ( R 2 = 0.748, P < 0.01). Developing field diagnostic criteria of M. capitata GA allowed for a detailed epizootiological assessment that determined several cofactors associated with disease severity. Such epizootiological analysis is applicable to future studies of GAs elsewhere.

  6. Demographic and occupational determinants of the work ability of firemen.

    PubMed

    Firoozeh, Marjan; Saremi, Mahnaz; Kavousi, Amir; Maleki, Azam

    2017-01-24

    Firefighters tackle various stressors that affect their health and job performance; therefore, assessment of their work ability is necessary. This study aimed to investigate the demographic and occupational determinants of the work ability of firemen. In this cross-sectional study, 375 firemen working in Tehran Fire Department were randomly selected. Demographic, occupational, and work ability index (WAI) questionnaires were applied as research tools. The mean firemen's WAI score was relatively high. There were significant relationships between WAI and age, body mass index, work experience, and weekly leisure-time physical exercise hours. Single employees, those who did not have extra jobs and did not smoke, had greater scores compared to their counterparts. Poisson regression revealed that age and weekly leisure-time physical exercise hours could affect WAI significantly. Although Iranian firemen revealed good work ability, recognizing factors affecting this ability and preparing facilities to promote their function is necessary.

  7. Volcanic rocks and subglacial volcanism beneath the West Antarctic Ice Sheet in the West Antarctic Rift System, (WAIS) from aeromagnetic and radar ice sounding - Thiel Subglacial Volcano as possible source of the ash layer in the WAISCORE

    NASA Astrophysics Data System (ADS)

    Behrendt, J. C.

    2012-12-01

    Radar ice sounding and aeromagnetic surveys reported over the West Antarctic Ice Sheet (WAIS) have been interpreted as evidence of subglacial volcanic eruptions over a very extensive area (>500,000 km2 ) of the volcanically active West Antarctic rift system interpreted as caused by subglacial volcanic rocks. Several active volcanoes have shown evidence of eruption through the WAIS and several other active volcanoes are present beneath the WAIS reported from radar and aeromagnetic data. Five-kilometer spaced coincident aeromagnetic and radar ice sounding surveys since 1990 provide three dimensional characterization of the magnetic field and bed topography beneath the ice sheet. These 5-50-km-width, semicircular magnetic anomalies range from 100->1000 nT as observed ~1 km over the 2-3 km thick ice have been interpreted as evidence of subglacial eruptions. Comparison of a carefully selected subset of ~400 of the >1000 high-amplitude anomalies in the CWA survey having topographic expression at the glacier bed, showed >80% had less than 200-m relief. About 18 high-amplitude subglacial magnetic sources also have high topography and bed relief (>600 m) interpreted as subaerially erupted volcanic peaks when the WAIS was absent, whose competent lava flows protected their edifices from erosion. All of these would have high elevation above sea-level, were the ice removed and glacial rebound to have occurred. Nine of these subaerially erupted volcanoes are concentrated in the WAIS divide area. Behrendt et al., 1998 interpreted a circular ring of positive magnetic anomalies overlying the WAIS divide as caused by a volcanic caldera. The area is characterized by high elevation bed topography. The negative regional magnetic anomaly surrounding the caldera anomalies was interpreted as the result of a shallow Curie isotherm. High heat flow inferred from temperature logging in the WAISCORE (G. Clow 2012, personal communication; Conway, 2011) and a prominent volcanic ash layer in the

  8. Four- and five-factor models of the WAIS-IV in a clinical sample: Variations in indicator configuration and factor correlational structure.

    PubMed

    Staffaroni, Adam M; Eng, Megan E; Moses, James A; Zeiner, Harriet Katz; Wickham, Robert E

    2018-05-01

    A growing body of research supports the validity of 5-factor models for interpreting the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). The majority of these studies have utilized the WAIS-IV normative or clinical sample, the latter of which differs in its diagnostic composition from the referrals seen at outpatient neuropsychology clinics. To address this concern, 2 related studies were conducted on a sample of 322 American military Veterans who were referred for outpatient neuropsychological assessment. In Study 1, 4 hierarchical models with varying indicator configurations were evaluated: 3 extant 5-factor models from the literature and the traditional 4-factor model. In Study 2, we evaluated 3 variations in correlation structure in the models from Study 1: indirect hierarchical (i.e., higher-order g), bifactor (direct hierarchical), and oblique models. The results from Study 1 suggested that both 4- and 5-factor models showed acceptable fit. The results from Study 2 showed that bifactor and oblique models offer improved fit over the typically specified indirect hierarchical model, and the oblique models outperformed the orthogonal bifactor models. An exploratory analysis found improved fit when bifactor models were specified with oblique rather than orthogonal latent factors. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  9. Distributed Bragg Reflectors With Reduced Optical Absorption

    DOEpatents

    Klem, John F.

    2005-08-16

    A new class of distributed Bragg reflectors has been developed. These distributed Bragg reflectors comprise interlayers positioned between sets of high-index and low-index quarter-wave plates. The presence of these interlayers is to reduce photon absorption resulting from spatially indirect photon-assisted electronic transitions between the high-index and low-index quarter wave plates. The distributed Bragg reflectors have applications for use in vertical-cavity surface-emitting lasers for use at 1.55 .mu.m and at other wavelengths of interest.

  10. Complex refractive index of Martian dust - Wavelength dependence and composition

    NASA Technical Reports Server (NTRS)

    Pang, K.; Ajello, J. M.

    1977-01-01

    The size distribution and complex refractive index of Martian dust-cloud particles observed in 1971 with the Mariner 9 UV spectrometer are determined by matching the observed single-scattering albedo and phase function with Mie-scattering calculations for size distributions of spheres. Values of phase function times single-scattering albedo are presented for 12 wavelength intervals in the range from 190 to 350 nm, and best-fit values are obtained for the absorption index. It is found that the absorption index of the dust particles increases with decreasing wavelength from 350 to about 210 nm and then drops off shortward of 210 nm, with a structural shoulder occurring in the absorption spectrum between 240 and 250 nm. A search for a candidate material that can explain the strong UV absorption yields TiO2, whose anatase polymorph has an absorption spectrum matching that of the Martian dust. The TiO2 content of the dust particles is estimated to be a few percent or less.

  11. Refractive index measurements in absorbing media with white light spectral interferometry.

    PubMed

    Arosa, Yago; Lago, Elena López; de la Fuente, Raúl

    2018-03-19

    White light spectral interferometry is applied to measure the refractive index in absorbing liquids in the spectral range of 400-1000 nm. We analyze the influence of absorption on the visibility of interferometric fringes and, accordingly, on the measurement of the refractive index. Further, we show that the refractive index in the absorption band can be retrieved by a two-step process. The procedure requires the use of two samples of different thickness, the thicker one to retrieve the refractive index in the transparent region and the thinnest to obtain the data in the absorption region. First, the refractive index values are retrieved with good accuracy in the transparent region of the material for 1-mm-thick samples. Second, these refractive index values serve also to precisely calculate the thickness of a thinner sample (~150 µm) since the accuracy of the methods depends strongly on the thickness of the sample. Finally, the refractive index is recovered for the entire spectral range.

  12. Work ability of workers in western China: reference data.

    PubMed

    Lin, Sihao; Wang, Zhiming; Wang, Mianzhen

    2006-03-01

    The Work Ability Index (WAI) is a validated and widely used research tool. Reference data for Chinese workers by age, gender and work content are poorly documented or lacking. To provide reference data for work ability among workers in western China. A random sample of 10 218 workers (including manual, professional, clerical and semi-skilled workers) in western China, aged 16-69 years, was taken from several studies and the WAI questionnaire was administered. All the WAI scores were distributed continuously and nearly normally. The WAI for female workers was significantly higher than for males (P < 0.01) and the 'poor' WAI category only accounted for 3% of females, against 6% of males. WAI scores declined with age and changed variably among workers according to work content and age. Mean WAI scores of manual workers declined rapidly beyond the age of 35 years, and beyond age 45 years for professional and clerical workers. WAI scores were distributed differently according to work content and age group (P < 0.01). WAI categories differed by work content and age group both for male and female workers. WAI is validated in Chinese occupational practices. Some reference data are different from Finnish data. This study provides gender, age and work-content-specific WAI reference values that will help enable comparison and intervention evaluation in further studies.

  13. Characterizing Protein Complexes with UV absorption, Light Scattering, and Refractive Index Detection.

    NASA Astrophysics Data System (ADS)

    Trainoff, Steven

    2009-03-01

    Many modern pharmaceuticals and naturally occurring biomolecules consist of complexes of proteins and polyethylene glycol or carbohydrates. In the case of vaccine development, these complexes are often used to induce or amplify immune responses. For protein therapeutics they are used to modify solubility and function, or to control the rate of degradation and elimination of a drug from the body. Characterizing the stoichiometry of these complexes is an important industrial problem that presents a formidable challenge to analytical instrument designers. Traditional analytical methods, such as using florescent tagging, chemical assays, and mass spectrometry perturb the system so dramatically that the complexes are often destroyed or uncontrollably modified by the measurement. A solution to this problem consists of fractionating the samples and then measuring the fractions using sequential non-invasive detectors that are sensitive to different components of the complex. We present results using UV absorption, which is primarily sensitive to the protein fraction, Light Scattering, which measures the total weight average molar mass, and Refractive Index detection, which measures the net concentration. We also present a solution of the problem inter-detector band-broadening problem that has heretofore made this approach impractical. Presented will be instrumentation and an analysis method that overcome these obstacles and make this technique a reliable and robust way of non-invasively characterizing these industrially important compounds.

  14. During air cool process aerosol absorption detection with photothermal interferometry

    NASA Astrophysics Data System (ADS)

    Li, Baosheng; Xu, Limei; Huang, Junling; Ma, Fei; Wang, Yicheng; Li, Zhengqiang

    2014-11-01

    This paper studies the basic principle of laser photothermal interferometry method of aerosol particles absorption coefficient. The photothermal interferometry method with higher accuracy and lower uncertainty can directly measure the absorption coefficient of atmospheric aerosols and not be affected by scattered light. With Jones matrix expression, the math expression of a special polarization interferometer is described. This paper using folded Jamin interferometer, which overcomes the influence of vibration on measuring system. Interference come from light polarization beam with two orthogonal and then combine to one beam, finally aerosol absorption induced refractive index changes can be gotten with four beam of phase orthogonal light. These kinds of styles really improve the stability of system and resolution of the system. Four-channel detections interact with interference fringes, to reduce the light intensity `zero drift' effect on the system. In the laboratory, this device typical aerosol absorption index, it shows that the result completely agrees with actual value. After heated by laser, cool process of air also show the process of aerosol absorption. This kind of instrument will be used to monitor ambient aerosol absorption and suspended particulate matter chemical component. Keywords: Aerosol absorption coefficient; Photothermal interferometry; Suspended particulate matter.

  15. Absorption enhancement and sensing properties of Ag diamond nanoantenna arrays

    NASA Astrophysics Data System (ADS)

    Yuan, Yu-Yang; Yuan, Zong-Heng; Li, Xiao-Nan; Wu, Jun; Zhang, Wen-Tao; Ye, Song

    2015-07-01

    Noble metal nanoantenna could effectively enhance light absorption and increase detection sensitivity. In this paper, we propose a periodic Ag diamond nanoantenna array to increase the absorption of thin-film solar cells and to improve the detection sensitivity via localized surface plasmon resonance. The effect of nanoantenna arrays on the absorption enhancement is theoretically investigated using the finite difference time domain (FDTD) method with manipulating the spectral response by geometrical parameters of nanoantennas. A maximum absorption enhancement factor of 1.51 has been achieved in this study. In addition, the relation between resonant wavelength (intensity reflectivity) and refractive index is discussed in detail. When detecting the environmental index using resonant wavelengths, a maximum detection sensitivity of about 837 nm/RIU (refractive index unit) and a resolution of about 10-3 RIU can be achieved. Moreover, when using the reflectivity, the sensitivity can be as high as 0.93 AU/RIU. Furthermore, we also have theoretically studied the effectiveness of nanoantennas in distinguishing chemical reagents, solution concentrations, and solution allocation ratios by detecting refractive index. From the results presented in this paper, we conclude that this work might be useful for biosensor detection and other types of detections. Project supported by the International Scientific and Technological Cooperation Projects of Guizhou Province, China (Grant No. 20117035) and the Program for Innovative Research Team of Guilin University of Electronic Technology, China (Grant No. IRTGUET).

  16. Latent mnemonic strengths are latent: a comment on Mickes, Wixted, and Wais (2007).

    PubMed

    Rouder, Jeffrey N; Pratte, Michael S; Morey, Richard D

    2010-06-01

    Mickes, Wixted, and Wais (2007) proposed a simple test of latent strength variability in recognition memory. They asked participants to rate their confidence using either a 20-point or a 99-point strength scale and plotted distributions of the resulting ratings. They found 25% more variability in ratings for studied than for new items, which they interpreted as providing evidence that latent mnemonic strength distributions are 25% more variable for studied than for new items. We show here that this conclusion is critically dependent on assumptions--so much so that these assumptions determine the conclusions. In fact, opposite conclusions, such that study does not affect the variability of latent strength, may be reached by making different but equally plausible assumptions. Because all measurements of mnemonic strength variability are critically dependent on untestable assumptions, all are arbitrary. Hence, there is no principled method for assessing the relative variability of latent mnemonic strength distributions.

  17. Interaction of lifestyle and work ability index in blue collar workers.

    PubMed

    Mohammadi, Saber; Ghaffari, Mostafa; Abdi, Alireza; Bahadori, Baharak; Mirzamohammadi, Elham; Attarchi, Mirsaeed

    2014-11-17

    Early labor force exit is one of the major problems worldwide. The present study investigates the relationship between work ability and lifestyle. This study was conducted at a manufacturing plant in Tehran in 2012. All 851 male workers in this plant were included into the study and their work ability was assessed using the Work Ability Index (WAI). Based on the obtained scores, the participants were then classified into four work ability groups (poor, moderate, good, or excellent). Moreover, the participants' lifestyles were studied in three areas, including physical activity, cigarette smoking, and Body Mass Index (BMI). The average work ability index score was 42.07, ranging from 7-48. Among the participants, 6.4% (43), 6.5% (44), 38.3% (259), and 48.8% (330) were in the groups with poor, moderate, good, and excellent work ability, respectively. The results of logistic regression analysis showed that there is a significant relationship between work ability and lifestyle (cigarette smoking, BMI, and physical activity) even after adjustment for confounding variables (P<0.05). According to the results of the present study, there might be a relationship between work ability and lifestyle (physical activity, BMI, cigarette smoking). Therefore, it is recommended to implement a lifestyle quality enhancement program to improve work ability in working environments.

  18. The Preservation and Recycling of Snow Pack Nitrate at the West Antarctic Ice Sheet (WAIS) Divide Ice Core Site from the Present Day to the Last Glacial Period.

    NASA Astrophysics Data System (ADS)

    Robinson, J. W.; Buffen, A.; Hastings, M. G.; Schauer, A. J.; Moore, L.; Isaacs, A.; Geng, L.; Savarino, J. P.; Alexander, B.

    2017-12-01

    We use observations of the nitrogen isotopic composition of nitrate (δ15N(NO3-)) from snow and ice collected at the West Antarctic ice sheet (WAIS) divide ice core site to quantify the preservation and recycling of snow nitrate. Ice-core samples cover a continuous section from 36 to 52 thousand years ago and discrete samples from the Holocene, the last glacial maximum (LGM), and the glacial-Holocene transition. Higher δ15N of nitrate is consistently associated with lower temperatures with δ15N(NO3-) varying from 26 to 45 ‰ during the last glacial period and from 1 to 45 ‰ between the Holocene and glacial periods, respectively. We attribute the higher δ15N in colder periods to lower snow accumulation rates which lead to greater loss of snow nitrate via photolysis before burial beneath the snow photic zone. Modeling of nitrate preservation in snow pack was performed for modern and LGM conditions. The model is used in conjunction with observations to estimate the fraction of snow nitrate that is photolyzed, re-oxidized, and re-deposited over WAIS divide versus the fraction of primary nitrate that is deposited via long range transport. We used these estimates of fractional loss of snow nitrate in different time periods to determine the variation in the deposition flux of primary nitrate at WAIS divide with climate. Our findings have implications for the climate sensitivity of the oxidizing capacity of the polar atmosphere and the interpretation of ice-core records of nitrate in terms of past atmospheric composition.

  19. Index of refraction engineering in five-level dressed interacting ground states atoms.

    PubMed

    Sagona-Stophel, Steven A; Weatherall, James Owen; Search, Christopher P

    2011-08-15

    We present a five-level atomic system in which the index of refraction of a probe laser can be enhanced or reduced below unity with vanishing absorption in the region between pairs of absorption and gain lines formed by dressing of the atoms with a control laser and rf/microwave fields. By weak incoherent pumping of the population into a single metastable state, one can create several narrow amplifying resonances. At frequencies between these gain lines and additional absorption lines, there exist regions of vanishing absorption but resonantly enhanced index of refraction. In Rb vapors with density N in units of cm(-3), we predict an index of refraction up to n≈√(1+1.2×10(-14)N) for the D1 line, which is more than an order of magnitude larger than other proposals for index of refraction enhancement. Furthermore, the index can be readily reduced below 1 by simply changing the sign of the probe or rf field detunings. This enhancement is robust with respect to homogeneous and inhomogeneous broadening. © 2011 Optical Society of America

  20. Harnessing Multiple Internal Reflections to Design Highly Absorptive Acoustic Metasurfaces

    NASA Astrophysics Data System (ADS)

    Shen, Chen; Cummer, Steven A.

    2018-05-01

    The rapid development of metasurfaces has enabled numerous intriguing applications with acoustically thin sheets. Here we report the theory and experimental realization of a nonresonant sound-absorbing strategy using metasurfaces by harnessing multiple internal reflections. We theoretically and numerically show that the higher-order diffraction of thin gradient-index metasurfaces is tied to multiple internal reflections inside the unit cells. Highly absorbing acoustic metasurfaces can be realized by enforcing multiple internal reflections together with a small amount of loss. A reflective gradient-index acoustic metasurface is designed based on the theory, and we further experimentally verify the performance using a three-dimensional printed prototype. Measurements show over 99% energy absorption at the peak frequency and a 95% energy absorption bandwidth of around 600 Hz. The proposed mechanism provides an alternative route for sound absorption without the necessity of high absorption of the individual unit cells.

  1. Work ability index, absenteeism and depression among patients with burnout syndrome.

    PubMed

    Pranjic, Nurka; Males-Bilic, Ljiljana

    2014-08-01

    The aim of this study is to estimate the association of burnout syndrome and depression; burnout syndrome and sick leave; and burnout syndrome with Work Ability Index in patients who suffer from stress at work. The control clinical study was conducted in the Teaching Department for Professional Pathology and Toxicology at the Primary Health Care Center Tuzla in the period from 2009 to 2014. The study included 140 patients exposed to different levels of stress at work. Besides conducted interviews and anamnesis with working anamnesis, physical examination, all patients were subjected to diagnostic package of questionnaires for assessing exposure to stress at work and its effects on health and work ability and Hamilton Rating Scale for screening depression. All patients were referred to the Department with suspected distress and burnout syndrome. For this study we used a questionnaire for measuring intensity of burnout (two categories exclude suffering from burnout syndrome: successfully overcome stress at work and sometimes feel stress at work and the other two reveal the initial and very high burn-out syndrome. Studied group was consisted of patients categorized with burnout syndrome (n=88). The questionnaire on the Work Ability Index (WAI) estimated characteristics of sick leave and prognostic factors with current work ability index. Lack of support at work with poor personal relations is the most common factor with the mobbing in burnout syndrome. Significantly more patients with the burnout syndrome suffered very severe depression 49%:37%; more use long sick leaves 53%:21%; several of them have poor WAI 51%:31% compared to those who are only exposed to stress at work (p=0.001). We found that the burn-out syndrome is predictor for developing depression (β=0.312, 95% CI, 0.114-0.353, p=0.001); absenteeism (β=0.285, 95% CI, 0.093-0.334, p=0.001); and a decline in working ability (β=0.413, 95% CI, 0.297-0.648). All the patients in whom it is found burnout

  2. Single-shot measurement of nonlinear absorption and nonlinear refraction.

    PubMed

    Jayabalan, J; Singh, Asha; Oak, Shrikant M

    2006-06-01

    A single-shot method for measurement of nonlinear optical absorption and refraction is described and analyzed. A spatial intensity variation of an elliptical Gaussian beam in conjugation with an array detector is the key element of this method. The advantages of this single-shot technique were demonstrated by measuring the two-photon absorption and free-carrier absorption in GaAs as well as the nonlinear refractive index of CS2 using a modified optical Kerr setup.

  3. A survey of TiOλ567 nm absorption in solar-type stars

    NASA Astrophysics Data System (ADS)

    Azizi, Fatemeh; Mirtorabi, Mohammad Taghi

    2018-04-01

    Molecular absorption bands are estimators of stellar activity and spot cycles on magnetically active stars. We have previously introduced a new colour index that compares absorption strength of the titanium oxide (TiO) at 567 nm with nearby continuum. In this paper, we implement this index to measure long-term activity variations and the statistical properties of the index in a sample of 302 solar-type stars from the High Accuracy Radial Velocity Planet search Spectrograph planet search programme. The results indicate a pattern of change in star's activity, covers a range of periods from 2 yr up to 17 yr.

  4. The relationship of the Reynolds Intellectual Assessment Scales and the Wechsler Adult Intelligence Scale-Third Edition.

    PubMed

    Smith, Billy L; McChristian, Chrystal L; Smith, Teresa D; Meaux, Julie

    2009-08-01

    The purpose of this study was to compare scores on the Reynolds Intellectual Assessment Scales (RIAS) with scores on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) in a group of college students diagnosed with a Learning Disability, Attention-Deficit Hyperactivity Disorder (ADHD), or a combination of the two. The RIAS Composite Index score was significantly higher than the WAIS-III Full Scale IQ, although scores on both tests were in the average range. Correlations between the two tests were significant on all measures. Male students were significantly higher than female students on both the RIAS Composite Index and on the WAIS-III Full Scale IQ. Although the ADHD group was higher on IQ than the Learning Disabled and combined disorder groups on all IQ measures, no significant differences were found.

  5. Using the OMI Aerosol Index and Absorption Aerosol Optical Depth to evaluate the NASA MERRA Aerosol Reanalysis

    NASA Astrophysics Data System (ADS)

    Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

    2014-12-01

    A radiative transfer interface has been developed to simulate the UV Aerosol Index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and Aerosol Absorption Optical Depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the Aerosol Robotic Network (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the South African and South American biomass burning regions indicates that revising the spectrally-dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons

  6. Using the OMI aerosol index and absorption aerosol optical depth to evaluate the NASA MERRA Aerosol Reanalysis

    NASA Astrophysics Data System (ADS)

    Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

    2015-05-01

    A radiative transfer interface has been developed to simulate the UV aerosol index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and aerosol absorption optical depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the AErosol RObotic NETwork (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model-produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the southern African and South American biomass burning regions indicates that revising the spectrally dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons

  7. Incidental recall on WAIS-R digit symbol discriminates Alzheimer's and Parkinson's diseases.

    PubMed

    Demakis, G J; Sawyer, T P; Fritz, D; Sweet, J J

    2001-03-01

    The purpose of this study was to examine how Alzheimer's (n = 37) and Parkinson's (n = 21) patients perform on the incidental recall adaptation to the Digit Symbol of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and how such performance is related to established cognitive efficiency and memory measures. This adaptation requires the examinee to complete the entire subtest and then, without warning, to immediately recall the symbols associated with each number. Groups did not differ significantly on standard Digit Symbol administration (90 seconds), but on recall Parkinson's patients recalled significantly more symbols and symbol-number pairs than Alzheimer's patients. Using only the number of symbols recalled, discriminate function analysis correctly classified 76% of these patients. Correlations between age-corrected scaled score, symbols incidentally recalled, and established measures of cognitive efficiency and memory provided evidence of convergent and divergent validity. Age-corrected scaled scores were more consistently and strongly related to cognitive efficiency, whereas symbols recalled were more consistently and strongly related to memory measures. These findings suggest that the Digit Symbol recall adaptation is actually assessing memory and that it can be another useful way to detect memory impairment. Copyright 2001 John Wiley & Sons, Inc.

  8. A Study of the Skin Absorption of Ethylbenzene in Man

    PubMed Central

    Dutkiewicz, Tadeusz; Tyras, Halina

    1967-01-01

    The absorption of ethylbenzene through the skin of the hand and the forearm in men was investigated experimentally. Both the absorption of liquid ethylbenzene and the absorption from aqueous solutions were studied. The rate of absorption of liquid ethylbenzene was 22 to 33 mg./cm.2/hr, and the rates from aqueous solutions were 118 and 215 μg./cm.2/hr from mean concentrations of 112 and 156 mg./litre. The mandelic acid excreted in urine was equivalent to about 4·6% of the absorbed dose—much less than after lung absorption. Urinary mandelic acid does not provide a reliable index of absorption when there is simultaneous skin and lung exposure. PMID:6073092

  9. Assessment of a model for achieving competency in administration and scoring of the WAIS-IV in post-graduate psychology students.

    PubMed

    Roberts, Rachel M; Davis, Melissa C

    2015-01-01

    There is a need for an evidence-based approach to training professional psychologists in the administration and scoring of standardized tests such as the Wechsler Adult Intelligence Scale (WAIS) due to substantial evidence that these tasks are associated with numerous errors that have the potential to significantly impact clients' lives. Twenty three post-graduate psychology students underwent training in using the WAIS-IV according to a best-practice teaching model that involved didactic teaching, independent study of the test manual, and in-class practice with teacher supervision and feedback. Video recordings and test protocols from a role-played test administration were analyzed for errors according to a comprehensive checklist with self, peer, and faculty member reviews. 91.3% of students were rated as having demonstrated competency in administration and scoring. All students were found to make errors, with substantially more errors being detected by the faculty member than by self or peers. Across all subtests, the most frequent errors related to failure to deliver standardized instructions verbatim from the manual. The failure of peer and self-reviews to detect the majority of the errors suggests that novice feedback (self or peers) may be ineffective to eliminate errors and the use of more senior peers may be preferable. It is suggested that involving senior trainees, recent graduates and/or experienced practitioners in the training of post-graduate students may have benefits for both parties, promoting a peer-learning and continuous professional development approach to the development and maintenance of skills in psychological assessment.

  10. Effects of fish with swim bladders on absorption and scintillation

    NASA Astrophysics Data System (ADS)

    Diachok, Orest

    2004-10-01

    Bioacoustic absorption spectroscopy (BAS) experiments, which were conducted in the Santa Barbara Channel in 2001 and 2002, were designed to investigate the effects of fish with swim bladders on absorption and scintillation. These experiments included a broadband source, which transmitted a sequence of 65-s-long tones between 0.25 and 10 kHz, and a vertical array which spanned most of the water column. The range was fixed. A fisheries echo sounder and trawls provided bio-acoustic parameters. Strongest absorption lines and highest values of the scintillation index were observed at night at about 1.1 kHz, the resonance frequency of 15 cm long sardines, when they were dispersed at an average depth of 13 m. Smaller absorption lines were correlated with other species. During the day sardines occupied a depth of about 50 m, where their extinction cross sections were diminished; some were dispersed and resonated at the frequency of individuals; others formed schools and resonated at collective frequencies. As a result of these phenomena, absorption lines due to sardines were much weaker, and the effect of this species on the scintillation index was not evident. [Work was supported by ONR.

  11. Tunable absorption resonances in the ultraviolet for InP nanowire arrays.

    PubMed

    Aghaeipour, Mahtab; Anttu, Nicklas; Nylund, Gustav; Samuelson, Lars; Lehmann, Sebastian; Pistol, Mats-Erik

    2014-11-17

    The ability to tune the photon absorptance spectrum is an attracting way of tailoring the response of devices like photodetectors and solar cells. Here, we measure the reflectance spectra of InP substrates patterned with arrays of vertically standing InP nanowires. Using the reflectance spectra, we calculate and analyze the corresponding absorptance spectra of the nanowires. We show that we can tune absorption resonances for the nanowire arrays into the ultraviolet by decreasing the diameter of the nanowires. When we compare our measurements with electromagnetic modeling, we generally find good agreement. Interestingly, the remaining differences between modeled and measured spectra are attributed to a crystal-phase dependence in the refractive index of InP. Specifically, we find indication of significant differences in the refractive index between the modeled zinc-blende InP nanowires and the measured wurtzite InP nanowires in the ultraviolet. We believe that such crystal-phase dependent differences in the refractive index affect the possibility to excite optical resonances in the large wavelength range of 345 < λ < 390 nm. To support this claim, we investigated how resonances in nanostructures can be shifted in wavelength by geometrical tuning. We find that dispersion in the refractive index can dominate over geometrical tuning and stop the possibility for such shifting. Our results open the door for using crystal-phase engineering to optimize the absorption in InP nanowire-based solar cells and photodetectors.

  12. Creating semiconductor metafilms with designer absorption spectra

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

    Kim, Soo Jin; Fan, Pengyu; Kang, Ju-Hyung

    The optical properties of semiconductors are typically considered intrinsic and fixed. Here we leverage the rapid developments in the field of optical metamaterials to create ultrathin semiconductor metafilms with designer absorption spectra. We show how such metafilms can be constructed by placing one or more types of high-index semiconductor antennas into a dense array with subwavelength spacings. It is argued that the large absorption cross-section of semiconductor antennas and their weak near-field coupling open a unique opportunity to create strongly absorbing metafilms whose spectral absorption properties directly reflect those of the individual antennas. Using experiments and simulations, we demonstrate thatmore » near-unity absorption at one or more target wavelengths of interest can be achieved in a sub-50-nm-thick metafilm using judiciously sized and spaced Ge nanobeams. The ability to create semiconductor metafilms with custom absorption spectra opens up new design strategies for planar optoelectronic devices and solar cells.« less

  13. Predicting long-term absenteeism from work in construction industry: a longitudinal study.

    PubMed

    Hoonakker, Peter; van Duivenbooden, Cor

    2012-01-01

    In this study we examine whether the Work Ability Index (WAI) has additional value in predicting long-term absenteeism in construction industry. Results of the study show that the WAI has additional value in predicting absenteeism, but that the amount of explained variance is low. This is partly due to the definition of absenteeism in The Netherlands, where this study took place.

  14. Investigation of the Relationship between Work Ability and Work-related Quality of Life in Nurses.

    PubMed

    Abbasi, Milad; Zakerian, Abolfazl; Akbarzade, Arash; Dinarvand, Nader; Ghaljahi, Maryam; Poursadeghiyan, Mohsen; Ebrahimi, Mohammad Hossein

    2017-10-01

    Work ability of nurses is an index of their job satisfaction and is a crucial factor in job quality and security. This study aimed to investigate the association between work ability and quality of working life and to determine the effective demographic and background variables, among nurses. The present study was conducted among nurses, working in educational hospitals under the supervision of Tehran University of Medical Sciences in 2014. Work Ability Index (WAI) and Work-related Quality of Life (WRQoL) were used. The mean WAI was significantly associated with total WRQoL score and the two of its sub-items including Stress at Work, and General Well-Being ( P -value=0.001). Moreover, the results showed a significant correlation between total WRQoL and WAI Subscales including mental resources ( P -value=0.001), number of current diseases ( P- value=0.02), and work ability in relation to the job demands ( P -value=0.04). The WRQoL and WAI showed significant associations with age and job experience ( P -value=0.001). The average score of WAI and WRQoL was statistically different among various working units ( P -value=0.001). Overall, results support the association between nurses work ability and WRQoL. Monitoring the WRQoL and work ability of employees would help organizations to know their status and take measures to ameliorate the working conditions.

  15. Determining the Accuracy of Self-Report Versus Informant-Report Using the Conners' Adult ADHD Rating Scale.

    PubMed

    Alexander, Lisa; Liljequist, Laura

    2016-04-01

    The present research examined the validity of self-report versus informant-report in relation to a performance-based indicator of adult ADHD. Archival data from 118 participants (52 males, 66 females) were used to compare Conners' Adult ADHD Rating Scale-Self-Report: Long Format (CAARS-S:L) and Conners' Adult ADHD Rating Scale-Observer Report: Long Format (CAARS-O:L) with discrepancy scores calculated between the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Verbal Comprehension Index - Working Memory Index (VCI - WMI) and Perceptual-Organizational Index - Processing Speed Index (POI - PSI) scaled scores. Neither the self- nor informant-report formats of the CAARS were better predictors of discrepancies between WAIS-III Index scores. Intercorrelations between the CAARS-S:L and CAARS-O:L revealed generally higher correlations between the same scales of different formats and among scales measuring externally visible symptoms. Furthermore, regression analysis indicated that both the CAARS-S:L and CAARS-O:L clinical scales contributed a significant proportion of variance in WAIS-III VCI - WMI discrepancy scores (14.7% and 16.4%, respectively). Results did not establish greater accuracy of self-report versus informant-report of ADHD symptomatology, rather demonstrate the need for multimodal assessment of ADHD in adults. © The Author(s) 2013.

  16. Visuospatial characteristics of an elderly Chinese population: results from the WAIS-R block design test.

    PubMed

    Yin, Shufei; Zhu, Xinyi; Huang, Xin; Li, Juan

    2015-01-01

    Visuospatial deficits have long been recognized as a potential predictor of dementia, with visuospatial ability decline having been found to accelerate in later stages of dementia. We, therefore, believe that the visuospatial performance of patients with mild cognitive impairment (MCI) and dementia (Dem) might change with varying visuospatial task difficulties. This study administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design Test (BDT) to determine whether visuospatial ability can help discriminate between MCI patients from Dem patients and normal controls (NC). Results showed that the BDT could contribute to the discrimination between MCI and Dem. Specifically, simple BDT task scores could best distinguish MCI from Dem patients, while difficult BDT task scores could contribute to discriminating between MCI and NC. Given the potential clinical value of the BDT in the diagnosis of Dem and MCI, normative data stratified by age and education for the Chinese elderly population are presented for use in research and clinical settings.

  17. The Work Ability of Hong Kong Construction Workers in Relation to Individual and Work-Related Factors.

    PubMed

    Ng, Jacky Y K; Chan, Alan H S

    2018-05-14

    The shortage in Hong Kong of construction workers is expected to worsen in future due to the aging population and increasing construction activity. Construction work is dangerous and to help reduce the premature loss of construction workers due to work-related disabilities, this study measured the work ability of 420 Hong Kong construction workers with a Work Ability Index (WAI) which can be used to predict present and future work performance. Given the importance of WAI, in this study the effects of individual and work-related factors on WAI were examined to develop and validate a WAI model to predict how individual and work-related factors affect work ability. The findings will be useful for formulating a pragmatic intervention program to improve the work ability of construction workers and keep them in the work force.

  18. Design and manufacture of high absorption metal dielectric coatings for the reduction of straylight

    NASA Astrophysics Data System (ADS)

    Cathelinaud, Michel; Lemarquis, Frédéric; Torchio, Philippe; Amra, Claude

    2017-11-01

    This paper describes the design and manufacture of broadband metal dielectric absorbers. First, we give some design principles to obtain achromatic absorption properties. Then, we describe a new method to determine the complex refractive index of metallic layers. A graded index model is developed to take account of the evolution of the film packing density. Manufacturing is detailed in the last section. Absorption levels higher than 99.9% have been measured over the visible range.

  19. Clinical utility of the Wechsler Adult Intelligence Scale-Fourth Edition after traumatic brain injury.

    PubMed

    Donders, Jacobus; Strong, Carrie-Ann H

    2015-02-01

    The performance of 100 patients with traumatic brain injury (TBI) on the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) was compared with that of 100 demographically matched neurologically healthy controls. Processing Speed was the only WAIS-IV factor index that was able to discriminate between persons with moderate-severe TBI on the one hand and persons with either less severe TBI or neurologically healthy controls on the other hand. The Processing Speed index also had acceptable sensitivity and specificity when differentiating between patients with TBI who either did or did not have scores in the clinically significant range on the Trail Making Test. It is concluded that WAIS-IV Processing Speed has acceptable clinical utility in the evaluation of patients with moderate-severe TBI but that it should be supplemented with other measures to assure sufficient accuracy in the diagnostic process. © The Author(s) 2014.

  20. A plant canopy light absorption model with application to wheat

    NASA Technical Reports Server (NTRS)

    Chance, J. E.; Lemaster, E. W.

    1977-01-01

    From the light absorption model the absorption of light in the photosynthetically active region of the spectrum was calculated for a Penjamo wheat crop for several situations including: (1) the percent absorption of the incident radiation by a canopy having a four layer structure; (2) the percent absorption of light by the individual layers within a four layer canopy and by the underlying soil; (3) the percent absorption of light by each vegetative canopy layer for variable sun angle; and (4) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three layer canopy. This calculation was also presented as a function of the leaf area index.

  1. Psychological variables and Wechsler Adult Intelligence Scale-IV performance.

    PubMed

    Gass, Carlton S; Gutierrez, Laura

    2017-01-01

    The MMPI-2 and WAIS-IV are commonly used together in neuropsychological evaluations yet little is known about their interrelationships. This study explored the potential influence of psychological factors on WAIS-IV performance in a sample of 180 predominantly male veteran referrals that underwent a comprehensive neuropsychological examination in a VA Medical Center. Exclusionary criteria included failed performance validity testing and self-report distortion on the MMPI-2. A Principal Components Analysis was performed on the 15 MMPI-2 content scales, yielding three broader higher-order psychological dimensions: Internalized Emotional Dysfunction (IED), Externalized Emotional Dysfunction (EED), and Fear. Level of IED was not related to performance on the WAIS-IV Full Scale IQ or its four indexes: (Verbal Comprehension, Perceptual Reasoning, Working Memory, and Processing Speed). EED was not related to WAIS-IV performance. Level of Fear, which encompasses health preoccupations (HEA) and distorted perceptions (BIZ), was significantly related to WAIS-IV Full Scale IQ and Verbal Comprehension. These results challenge the common use of high scores on the MMPI-2 IED measures (chiefly depression and anxiety) to explain deficient WAIS-IV performance. In addition, they provide impetus for further investigation of the relation between verbal intelligence and Fear.

  2. The relative importance of aerosol scattering and absorption in remote sensing

    NASA Technical Reports Server (NTRS)

    Fraser, R. S.; Kaufman, Y. J.

    1985-01-01

    Previous attempts to explain the effect of aerosols on satellite measurements of surface properties for the visible and near-infrared spectrum have emphasized the amount of aerosols without consideration of their absorption properties. In order to estimate the importance of absorption, the radiances of the sunlight scattered from models of the earth-atmosphere system are computed as functions of the aerosol optical thickness and absorption. The absorption effect is small where the surface reflectance is weak, but is important for strong reflectance. These effects on classification of surface features, measuring vegetation index, and measuring surface reflectance are presented.

  3. Pain, fatigue and hand function closely correlated to work ability and employment status in systemic sclerosis.

    PubMed

    Sandqvist, Gunnel; Scheja, Agneta; Hesselstrand, Roger

    2010-09-01

    To identify factors, individual and work related, influencing work ability, and to assess the association between work ability and employment status, activities of daily life (ADLs) and quality of life in patients with SSc. Fifty-seven consecutive patients (53 females/4 males) with SSc (47 lcSSc/10 dcSSc) were included. Median age was 58 [interquartile range (IQR) 47-62] years and disease duration 14 (9-19) years. The patients were assessed for socio-demographic characteristics, disease parameters, symptoms, work ability, empowerment and adaptations in a workplace, social support, ADLs and quality of life. Work ability, assessed with the Work Ability Index (WAI) could be evaluated in 48 of 57 patients. The correlation between employment status and WAI was good (r(s) = 0.79, P < 0.001). Thirteen patients had good or excellent WAI, 15 had less good and 20 had poor WAI. There were no significant differences between subgroups of WAI and socio-demographic characteristics, disease duration or degree of skin and lung involvement. However, patients with good WAI expressed milder perceived symptoms (pain, fatigue and impaired hand function; P < 0.001). Patients with better WAI had better competence (P < 0.001), better possibility of adaptations at work (P < 0.01) and impact at work (P < 0.01) than those with poorer WAI. In SSc, pain, fatigue and impaired hand function have a dominant impact on the WAI. Employment interventions should include support in job adaptations as well as self-management strategies to help patients deal with pain and fatigue and to enhance the confidence to perform their work.

  4. Longitudinal associations between stressors and work ability in hospital workers.

    PubMed

    Carmen Martinez, Maria; da Silva Alexandre, Tiago; Dias de Oliveira Latorre, Maria do Rosario; Marina Fischer, Frida

    This study sought to assess associations between work stressors and work ability in a cohort (2009-2012) of 498 hospital workers. Time-dependent variables associated with the Work Ability Index (WAI) were evaluated using general linear mixed models. Analyses included effects of individual and work characteristics. Except for work demands, the work stressors (job control, social support, effort-reward imbalance, overcommitment and work-related activities that cause pain/injury) were associated with WAI (p < 0.050) at intercept and in the time interaction. Daytime work and morning shift work were associated with decreased WAI (p < 0.010). Work stressors negatively affected work ability over time independently of other variables.

  5. Investigation of the Relationship between Work Ability and Work-related Quality of Life in Nurses

    PubMed Central

    ABBASI, Milad; ZAKERIAN, Abolfazl; AKBARZADE, Arash; DINARVAND, Nader; GHALJAHI, Maryam; POURSADEGHIYAN, Mohsen; EBRAHIMI, Mohammad Hossein

    2017-01-01

    Background: Work ability of nurses is an index of their job satisfaction and is a crucial factor in job quality and security. This study aimed to investigate the association between work ability and quality of working life and to determine the effective demographic and background variables, among nurses. Methods: The present study was conducted among nurses, working in educational hospitals under the supervision of Tehran University of Medical Sciences in 2014. Work Ability Index (WAI) and Work-related Quality of Life (WRQoL) were used. Results: The mean WAI was significantly associated with total WRQoL score and the two of its sub-items including Stress at Work, and General Well-Being (P-value=0.001). Moreover, the results showed a significant correlation between total WRQoL and WAI Subscales including mental resources (P-value=0.001), number of current diseases (P-value=0.02), and work ability in relation to the job demands (P-value=0.04). The WRQoL and WAI showed significant associations with age and job experience (P-value=0.001). The average score of WAI and WRQoL was statistically different among various working units (P-value=0.001). Conclusion: Overall, results support the association between nurses work ability and WRQoL. Monitoring the WRQoL and work ability of employees would help organizations to know their status and take measures to ameliorate the working conditions. PMID:29308385

  6. The Work Ability of Hong Kong Construction Workers in Relation to Individual and Work-Related Factors

    PubMed Central

    Ng, Jacky Y. K.

    2018-01-01

    The shortage in Hong Kong of construction workers is expected to worsen in future due to the aging population and increasing construction activity. Construction work is dangerous and to help reduce the premature loss of construction workers due to work-related disabilities, this study measured the work ability of 420 Hong Kong construction workers with a Work Ability Index (WAI) which can be used to predict present and future work performance. Given the importance of WAI, in this study the effects of individual and work-related factors on WAI were examined to develop and validate a WAI model to predict how individual and work-related factors affect work ability. The findings will be useful for formulating a pragmatic intervention program to improve the work ability of construction workers and keep them in the work force. PMID:29758018

  7. Education-stratified base-rate information on discrepancy scores within and between the Wechsler Adult Intelligence Scale--Third Edition and the Wechsler Memory Scale--Third Edition.

    PubMed

    Dori, Galit A; Chelune, Gordon J

    2004-06-01

    The Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997a) and the Wechsler Memory Scale--Third Edition (WMS-III; D. Wechsler, 1997b) are 2 of the most frequently used measures in psychology and neuropsychology. To facilitate the diagnostic use of these measures in the clinical decision-making process, this article provides information on education-stratified, directional prevalence rates (i.e., base rates) of discrepancy scores between the major index scores for the WAIS-III, the WMS-III, and between the WAIS-III and WMS-III. To illustrate how such base-rate data can be clinically used, this article reviews the relative risk (i.e., odds ratio) of empirically defined "rare" cognitive deficits in 2 of the clinical samples presented in the WAIS-III--WMS-III Technical Manual (The Psychological Corporation, 1997). ((c) 2004 APA, all rights reserved)

  8. A 62 ka record from the WAIS Divide ice core with annual resolution to 30 ka (so far)

    NASA Astrophysics Data System (ADS)

    Fudge, T. J.; Taylor, K.; McGwire, K.; Brook, E.; Sowers, T.; Steig, E.; White, J.; Vaughn, B.; Bay, R.; McConnell, J.; Waddington, E.; Conway, H.; Clow, G.; Cuffey, K.; Cole-Dai, J.; Ferris, D.; Severinghaus, J.

    2012-04-01

    Drilling of the West Antarctic Ice Sheet (WAIS) Divide ice core has been completed to a depth of 3400 m, about 60 meters above the bed. We present an annually resolved time scale for the most recent 30ka (to 2800 m) based on electrical conductivity measurements, called "timescale WDC06A-5". Below 2800 m the ice is dated by matching isotopes, methane, and/or dust records to other ice cores. Optical borehole logging provides stratigraphic ties to other cores for the bottom-most 75 m that was drilled in December 2011, and indicates the bottom-most ice has an age of 62 ka. The relatively young ice at depth is likely the result of basal melting. The inferred annual layer thickness of the deep ice is >1 cm, suggesting that annual layer counting throughout the entire core may be possible with continuous flow analysis of the ice core chemistry; however, the annual signal in the electrical measurements fades at about 30 ka. We compare the WDC06A-5 timescale through the glacial-interglacial transition with the Greenland GICC05 and GISP2 timescales via rapid variations in methane. We calculate a preliminary delta-age with: 1) accumulation rate inferred from the annual layer thicknesses and thinning functions computed with a 1-D ice flow model, and 2) surface temperature inferred from the low resolution d18O record and a preliminary borehole temperature profile. The WDC06A-5 timescale agrees with the GICC05 and GISP2 timescales to within decades at the 8.2k event and the ACR termination (Younger Dryas/Preboreal transition, 11.7 ka). This is within the delta-age and correlation uncertainties. At the rapid methane drop at ~12.8 ka, the WDC06A-5 timescale is ~150 years older than GICC05 and ~90 older than GISP2; while at ~14.8 ka, the timescales once again agree within the delta-age and correlation uncertainties. The cause of the age discrepancy at 12.8 ka is unclear. We also compare the WDC06A-5 timescale at Dansgaard-Oeschger events 3 and 4 (~27.5 and 29 ka) to the

  9. Cavity-enhanced measurements for determining dielectric-membrane thickness and complex index of refraction.

    PubMed

    Stambaugh, Corey; Durand, Mathieu; Kemiktarak, Utku; Lawall, John

    2014-08-01

    The material properties of silicon nitride (SiN) play an important role in the performance of SiN membranes used in optomechanical applications. An optimum design of a subwavelength high-contrast grating requires accurate knowledge of the membrane thickness and index of refraction, and its performance is ultimately limited by material absorption. Here we describe a cavity-enhanced method to measure the thickness and complex index of refraction of dielectric membranes with small, but nonzero, absorption coefficients. By determining Brewster's angle and an angle at which reflection is minimized by means of destructive interference, both the real part of the index of refraction and the sample thickness can be measured. A comparison of the losses in the empty cavity and the cavity containing the dielectric sample provides a measurement of the absorption.

  10. Replacement of the Faces subtest by Visual Reproductions within Wechsler Memory Scale-Third Edition (WMS-III) visual memory indexes: implications for discrepancy analysis.

    PubMed

    Hawkins, Keith A; Tulsky, David S

    2004-06-01

    Within discrepancy analysis differences between scores are examined for abnormality. Although larger differences are generally associated with rising impairment probabilities, the relationship between discrepancy size and abnormality varies across score pairs in relation to the correlation between the contrasted scores in normal subjects. Examinee ability level also affects the size of discrepancies observed normally. Wechsler Memory Scale-Third Edition (WMS-III) visual index scores correlate only modestly with other Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) and WMS-III index scores; consequently, differences between these scores and others have to be very large before they become unusual, especially for subjects of higher intelligence. The substitution of the Faces subtest by Visual Reproductions within visual memory indexes formed by the combination of WMS-III visual subtests (creating immediate recall, delayed recall, and combined immediate and delayed index scores) results in higher correlation coefficients, and a decline in the discrepancy size required to surpass base rate thresholds for probable impairment. This gain appears not to occur at the cost of a diminished sensitivity to diverse pathologies. New WMS-III discrepancy base rate data are supplied to complement those currently available to clinicians.

  11. A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release

    NASA Astrophysics Data System (ADS)

    Trump, Jonathan R.; Hall, Patrick B.; Reichard, Timothy A.; Richards, Gordon T.; Schneider, Donald P.; Vanden Berk, Daniel E.; Knapp, Gillian R.; Anderson, Scott F.; Fan, Xiaohui; Brinkman, J.; Kleinman, S. J.; Nitta, Atsuko

    2006-07-01

    We present a total of 4784 unique broad absorption line quasars from the Sloan Digital Sky Survey Third Data Release. An automated algorithm was used to match a continuum to each quasar and to identify regions of flux at least 10% below the continuum over a velocity range of at least 1000 km s-1 in the C IV and Mg II absorption regions. The model continuum was selected as the best-fit match from a set of template quasar spectra binned in luminosity, emission line width, and redshift, with the power-law spectral index and amount of dust reddening as additional free parameters. We characterize our sample through the traditional ``balnicity'' index and a revised absorption index, as well as through parameters such as the width, outflow velocity, fractional depth, and number of troughs. From a sample of 16,883 quasars at 1.7<=z<=4.38, we identify 4386 (26.0%) quasars with broad C IV absorption, of which 1756 (10.4%) satisfy traditional selection criteria. From a sample of 34,973 quasars at 0.5<=z<=2.15, we identify 457 (1.31%) quasars with broad Mg II absorption, 191 (0.55%) of which satisfy traditional selection criteria. We also provide a supplementary list of 39 visually identified z>4.38 quasars with broad C IV absorption. We find that broad absorption line quasars may have broader emission lines on average than other quasars.

  12. West Antarctic Ice Sheet cloud cover and surface radiation budget from NASA A-Train satellites

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

    Scott, Ryan C.; Lubin, Dan; Vogelmann, Andrew M.

    Clouds are an essential parameter of the surface energy budget influencing the West Antarctic Ice Sheet (WAIS) response to atmospheric warming and net contribution to global sea-level rise. A four-year record of NASA A-Train cloud observations is combined with surface radiation measurements to quantify the WAIS radiation budget and constrain the three-dimensional occurrence frequency, thermodynamic phase partitioning, and surface radiative effect of clouds over West Antarctica (WA). The skill of satellite-modeled radiative fluxes is confirmed through evaluation against measurements at four Antarctic sites (WAIS Divide Ice Camp, Neumayer, Syowa, and Concordia Stations). And due to perennial high-albedo snow and icemore » cover, cloud infrared emission dominates over cloud solar reflection/absorption leading to a positive net all-wave cloud radiative effect (CRE) at the surface, with all monthly means and 99.15% of instantaneous CRE values exceeding zero. The annual-mean CRE at theWAIS surface is 34 W m -2, representing a significant cloud-induced warming of the ice sheet. Low-level liquid-containing clouds, including thin liquid water clouds implicated in radiative contributions to surface melting, are widespread and most frequent in WA during the austral summer. Clouds warm the WAIS by 26 W m -2, in summer, on average, despite maximum offsetting shortwave CRE. Glaciated cloud systems are strongly linked to orographic forcing, with maximum incidence on the WAIS continuing downstream along the Transantarctic Mountains.« less

  13. West Antarctic Ice Sheet cloud cover and surface radiation budget from NASA A-Train satellites

    DOE PAGES

    Scott, Ryan C.; Lubin, Dan; Vogelmann, Andrew M.; ...

    2017-04-26

    Clouds are an essential parameter of the surface energy budget influencing the West Antarctic Ice Sheet (WAIS) response to atmospheric warming and net contribution to global sea-level rise. A four-year record of NASA A-Train cloud observations is combined with surface radiation measurements to quantify the WAIS radiation budget and constrain the three-dimensional occurrence frequency, thermodynamic phase partitioning, and surface radiative effect of clouds over West Antarctica (WA). The skill of satellite-modeled radiative fluxes is confirmed through evaluation against measurements at four Antarctic sites (WAIS Divide Ice Camp, Neumayer, Syowa, and Concordia Stations). And due to perennial high-albedo snow and icemore » cover, cloud infrared emission dominates over cloud solar reflection/absorption leading to a positive net all-wave cloud radiative effect (CRE) at the surface, with all monthly means and 99.15% of instantaneous CRE values exceeding zero. The annual-mean CRE at theWAIS surface is 34 W m -2, representing a significant cloud-induced warming of the ice sheet. Low-level liquid-containing clouds, including thin liquid water clouds implicated in radiative contributions to surface melting, are widespread and most frequent in WA during the austral summer. Clouds warm the WAIS by 26 W m -2, in summer, on average, despite maximum offsetting shortwave CRE. Glaciated cloud systems are strongly linked to orographic forcing, with maximum incidence on the WAIS continuing downstream along the Transantarctic Mountains.« less

  14. Absorption and quasiguided mode analysis of organic solar cells with photonic crystal photoactive layers.

    PubMed

    Tumbleston, John R; Ko, Doo-Hyun; Samulski, Edward T; Lopez, Rene

    2009-04-27

    We analyze optical absorption enhancements and quasiguided mode properties of organic solar cells with highly ordered nanostructured photoactive layers comprised of the bulk heterojunction blend, poly-3-hexylthiophene/[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) and a low index of refraction conducting material (LICM). This photonic crystal geometry is capable of enhancing spectral absorption by approximately 17% in part due to the excitation of quasiguided modes near the band edge of P3HT:PCBM. A nanostructure thickness between 200 nm and 300 nm is determined to be optimal, while the LICM must have an index of refraction approximately 0.3 lower than P3HT:PCBM to produce absorption enhancements. Quasiguided modes that differ in lifetime by an order of magnitude are also identified and yield absorption that is concentrated in the P3HT:PCBM flash layer.

  15. Constraints on ice volume changes of the WAIS and Ross Ice Shelf since the LGM based on cosmogenic exposure ages in the Darwin-Hatherton glacial system of the Transantarctic Mountains

    NASA Astrophysics Data System (ADS)

    Fink, David; Storey, Bryan; Hood, David; Joy, Kurt; Shulmeister, James

    2010-05-01

    Quantitative assessment of the spatial and temporal scale of ice volume change of the West Antarctic ice sheet (WAIS) and Ross Ice Shelf since the last glacial maximum (LGM) ~20 ka is essential to accurately predict ice sheet response to current and future climate change. Although global sea level rose by approximately 120 metres since the LGM, the contribution of polar ice sheets is uncertain and the timing of any such contribution is controversial. Mackintosh et al (2007) suggest that sectors of the EAIS, similar to those studied at Framnes Mountains where the ice sheet slowly calves at coastal margins, have made marginal contributions to global sea-level rise between 13 and 7 ka. In contrast, Stone et al (2003) document continuing WAIS decay during the mid-late Holocene, raising the question of what was the response of the WAIS since LGM and into the Holocene. Terrestrial evidence is restricted to sparse coastal oasis and ice free mountains which archive limits of former ice advances. Mountain ranges flanking the Darwin-Hatherton glaciers exhibit well-defined moraines, weathering signatures, boulder rich plateaus and glacial tills, which preserve the evidence of advance and retreat of the ice sheet during previous glacial cycles. Previous studies suggest a WAIS at the LGM in this location to be at least 1,000 meters thicker than today. As part of the New Zealand Latitudinal Gradient Project along the Transantarctic, we collected samples for cosmogenic exposure dating at a) Lake Wellman area bordering the Hatherton Glacier, (b) Roadend Nunatak at the confluence of the Darwin and Hatherton glaciers and (c) Diamond Hill which is positioned at the intersection of the Ross Ice Shelf and Darwin Glacier outlet. While the technique of exposure dating is very successful in mid-latitude alpine glacier systems, it is more challenging in polar ice-sheet regions due to the prevalence of cold-based ice over-riding events and absence of outwash processes which removes

  16. Selective sensitivity of Mueller imaging for tissue scattering over absorption changes in cancer mimicking phantoms

    NASA Astrophysics Data System (ADS)

    Fathima, Adeeba; Sharma B. S., Mahima; N., Sujatha

    2018-03-01

    Tissue characterization using optical polarimetry, especially Mueller imaging is receiving sustained interest due to its potential in achieving optical contrast between normal and malignant variations. This is particularly important in identifying the margin of malignant growth in suspected tissue regions for accurate surgical removal, or in aiding the sampling procedure during biopsy. The sensitivity of Mueller matrix derived depolarization index to the combined effects of changes in scattering and absorption occurring in a cancerous growth is illustrated in this study. Depolarization imaging is shown to be useful in demarcating the boundary of two regions of differing optical properties using a tissue phantom, modeled according to the changes expected during cancerous growth in tissue. Tissue scattering and absorption are expected to generally increase with the nuclear size change and crowding as well as angiogenesis associated with malignancy. We have observed that there is selective sensitivity for the Mueller elements and derived depolarization index to tissue scattering over absorption in the object field. Although the scattering and absorption are expected to increase and decrease depolarization respectively, the optical contrast of Mueller images and the derived depolarization index between normal and cancerous tissue is found appreciable in this region.

  17. Searching for a neurologic injury's Wechsler Adult Intelligence Scale-Third Edition profile.

    PubMed

    Gonçalves, Marta A; Moura, Octávio; Castro-Caldas, Alexandre; Simões, Mário R

    2017-01-01

    This study aimed to investigate the presence of a Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) cognitive profile in a Portuguese neurologic injured sample. The Portuguese WAIS-III was administered to 81 mixed neurologic patients and 81 healthy matched controls selected from the Portuguese standardization sample. Although the mixed neurologic injury group performed significantly lower than the healthy controls for the majority of the WAIS-III scores (i.e., composite measures, discrepancies, and subtests), the mean scores were within the normal range and, therefore, at risk of being unobserved in a clinical evaluation. ROC curves analysis showed poor to acceptable diagnostic accuracy for the WAIS-III composite measures and subtests (Working Memory Index and Digit Span revealed the highest accuracy for discriminating between participants, respectively). Multiple regression analysis showed that both literacy and the presence of brain injury were significant predictors for all of the composite measures. In addition, multiple regression analysis also showed that literacy, age of injury onset, and years of survival predicted all seven composite measures for the mixed neurologic injured group. Despite the failure to find a WAIS-III cognitive profile for mixed neurologic patients, the results showed a significant influence of brain lesion and literacy in the performance of the WAIS-III.

  18. Enhancing maximum measurable sound reduction index using sound intensity method and strong receiving room absorption.

    PubMed

    Hongisto, V; Lindgren, M; Keränen, J

    2001-01-01

    The sound intensity method is usually recommended instead of the pressure method in the presence of strong flanking transmission. Especially when small and/or heavy specimens are tested, the flanking often causes problems in laboratories practicing only the pressure method. The purpose of this study was to determine experimentally the difference between the maximum sound reduction indices obtained by the intensity method, RI,max, and by the pressure method, Rmax. In addition, the influence of adding room absorption to the receiving room was studied. The experiments were carried out in an ordinary two-room test laboratory. The exact value of RI,max was estimated by applying a fitting equation to the measured data points. The fitting equation involved the dependence of the pressure-intensity indicator on measured acoustical parameters. In an empty receiving room, the difference between RI,max and Rmax was 4-15 dB, depending on frequency. When the average reverberation time was reduced from 3.5 to 0.6 s, the values of RI,max increased by 2-10 dB compared to the results in the empty room. Thus, it is possible to measure wall structures having 9-22 dB better sound reduction index using the intensity method than with the pressure method. This facilitates the measurements of small and/or heavy specimens in the presence of flanking. Moreover, when new laboratories are designed, the intensity method is an alternative to the pressure method which presupposes expensive isolation structures between the rooms.

  19. Broadband giant-refractive-index material based on mesoscopic space-filling curves

    NASA Astrophysics Data System (ADS)

    Chang, Taeyong; Kim, Jong Uk; Kang, Seung Kyu; Kim, Hyowook; Kim, Do Kyung; Lee, Yong-Hee; Shin, Jonghwa

    2016-08-01

    The refractive index is the fundamental property of all optical materials and dictates Snell's law, propagation speed, wavelength, diffraction, energy density, absorption and emission of light in materials. Experimentally realized broadband refractive indices remain <40, even with intricately designed artificial media. Herein, we demonstrate a measured index >1,800 resulting from a mesoscopic crystal with a dielectric constant greater than three million. This gigantic enhancement effect originates from the space-filling curve concept from mathematics. The principle is inherently very broad band, the enhancement being nearly constant from zero up to the frequency of interest. This broadband giant-refractive-index medium promises not only enhanced resolution in imaging and raised fundamental absorption limits in solar energy devices, but also compact, power-efficient components for optical communication and increased performance in many other applications.

  20. Self-Reported Poor Work Ability--An Indicator of Need for Rehabilitation? A Cross-Sectional Study of a Sample of German Employees.

    PubMed

    Bethge, Matthias; Spanier, Katja; Neugebauer, Tjark; Mohnberg, Inka; Radoschewski, Friedrich Michael

    2015-11-01

    The purpose of this study was to assess associations of self-reported work ability as measured by the Work Ability Index (WAI) with modifiable behavioral and occupational health risks, health service utilization, and intended rehabilitation and pension requests. This is a cross-sectional study of a random sample of German employees aged 40-54 yrs on sickness benefits in 2012 (trial registration: DRKS00004824). In total, 1312 male and 1502 female employees were included in the analyses. Low WAI scores (i.e., <37 points) were associated with a higher prevalence of occupational and behavioral health risks; a higher likelihood of frequent visits to general, somatic, and psychologic specialists as well as hospital stays; and four to six times higher risks of intended rehabilitation and pension requests. A two-item version of the WAI was as strongly associated with intended rehabilitation and pension requests as the total score. This study indicates that the WAI is a sensitive screening tool to identify workers on sick leave with a probable need for rehabilitation. The WAI could support the assessment of need for rehabilitation by occupational health services in return-to-work strategies, which include the opportunity to access multiprofessional rehabilitation.

  1. Comparing Canadian and American normative scores on the Wechsler Adult Intelligence Scale-Fourth Edition.

    PubMed

    Harrison, Allyson G; Armstrong, Irene T; Harrison, Laura E; Lange, Rael T; Iverson, Grant L

    2014-12-01

    Psychologists practicing in Canada must decide which set of normative data to use for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). The purpose of this study was to compare the interpretive effects of applying American versus Canadian normative systems in a sample of 432 Canadian postsecondary-level students who were administered the WAIS-IV as part of an evaluation for a learning disability, attention-deficit hyperactivity disorder, or other mental health problems. Employing the Canadian normative system yielded IQ, Index, and subtest scores that were systematically lower than those obtained using the American norms. Furthermore, the percentage agreement in normative classifications, defined as American and Canadian index scores within five points or within the same classification range, was between 49% and 76%. Substantial differences are present between the American and Canadian WAIS-IV norms. Clinicians should consider carefully the implications regarding which normative system is most appropriate for specific types of evaluations. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Linear and nonlinear optical absorption coefficients and refractive index changes in GaN/Al{sub x}Ga{sub (1−x)}N double quantum wells operating at 1.55 μm

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

    Dakhlaoui, Hassen

    2015-04-07

    In the present paper, the linear and nonlinear optical absorption coefficients and refractive index changes between the ground and the first excited states in double GaN/Al{sub x}Ga{sub (1−x)}N quantum wells are studied theoretically. The electronic energy levels and their corresponding wave functions are obtained by solving Schrödinger-Poisson equations self-consistently within the effective mass approximation. The obtained results show that the optical absorption coefficients and refractive index changes can be red- and blue-shifted through varying the left quantum well width and the aluminum concentration x{sub b2} of the central barrier, respectively. These structural parameters are found to present optimum values formore » carrying out the transition of 0.8 eV (1.55 μm). Furthermore, we show that the desired transition can also be achieved by replacing the GaN in the left quantum well with Al{sub y}Ga{sub (1−y)}N and by varying the aluminum concentration y{sub Al}. The obtained results give a new degree of freedom in optoelectronic device applications such as optical fiber telecommunications operating at (1.55 μm)« less

  3. [Study on relationship between fatigue and work ability in chemistry workers].

    PubMed

    Wu, Si-Ying; Wang, Mian-Zhen; Wang, Zhi-Ming; Lan, Ya-Jia

    2005-01-01

    Explore the relationship between fatigue and work ability in 976 chemistry workers. A test of fatigue and work ability was carried out with fatigue scale and work ability index (WAI) for 976 workers, other influence factors of the work ability (such as work environment, labor load, job factors) were investigated with questionnaire. (1) The frequency of fatigue of the unmarried workers was significantly lower than that of the married workers and other marital status workers, while the score of WAI of the unmarried was significantly higher than that of those( P < 0.05); (2) the frequency of fatigue of the mental workers was significantly lower than that of the mixed physical and mental workers, while the score of WAI of the mental workers was significantly higher than that of physical workers and mixed physical and mental workers ( P < 0.05); (3) compared with the workers free of fatigue, the other workers had lower WAI scores; (4) the fatigue score correlated negatively to the WAI score (r = -0.499, P < 0.01); (5) Cumulative odds model analysis showed that after controlling the other risk factors, fatigue was an important risk factor of work ability (OR = 4.005). Fatigue has affected work ability in chemistry workers, the frequency of fatigue is higher, the score of WAI is lower.

  4. A naked eye refractive index sensor with a visible multiple peak metamaterial absorber.

    PubMed

    Ma, Heli; Song, Kun; Zhou, Liang; Zhao, Xiaopeng

    2015-03-26

    We report a naked eye refractive index sensor with a visible metamaterial absorber. The visible metamaterial absorber consisting of a silver dendritic/dielectric/metal structure shows multiple absorption peaks. By incorporating a gain material (rhodamine B) into the dielectric layer, the maximal magnitude of the absorption peak can be improved by about 30%. As the metamaterial absorber is sensitive to the refractive index of glucose solutions, it can function as a sensor that quickly responds to variations of the refractive index of the liquid. Meanwhile, since the response is presented via color changes, it can be clearly observed by the naked eyes. Further experiments have confirmed that the sensor can be used repeatedly.

  5. Refractive Index and Absorption Attribution of Highly Absorbing Brown Carbon Aerosols from an Urban Indian City-Kanpur.

    PubMed

    Shamjad, P M; Tripathi, S N; Thamban, Navaneeth M; Vreeland, Heidi

    2016-11-24

    Atmospheric aerosols influence Earth's radiative balance, having both warming and cooling effects. Though many aerosols reflect radiation, carbonaceous aerosols such as black carbon and certain organic carbon species known as brown carbon have the potential to warm the atmosphere by absorbing light. Black carbon absorbs light over the entire solar spectrum whereas brown carbon absorbs near-UV wavelengths and, to a lesser extent, visible light. In developing countries, such as India, where combustion sources are prolific, the influence of brown carbon on absorption may be significant. In order to better characterize brown carbon, we present experimental and modeled absorption properties of submicron aerosols measured in an urban Indian city (Kanpur). Brown carbon here is found to be fivefold more absorbing at 365 nm wavelength compared to previous studies. Results suggest ~30% of total absorption in Kanpur is attributed to brown carbon, with primary organic aerosols contributing more than secondary organics. We report the spectral brown carbon refractive indices along with an experimentally constrained estimate of the influence of aerosol mixing state on absorption. We conclude that brown carbon in Kanpur is highly absorbing in nature and that the mixing state plays an important role in light absorption from volatile species.

  6. Refractive Index and Absorption Attribution of Highly Absorbing Brown Carbon Aerosols from an Urban Indian City-Kanpur

    PubMed Central

    Shamjad, P. M.; Tripathi, S. N.; Thamban, Navaneeth M.; Vreeland, Heidi

    2016-01-01

    Atmospheric aerosols influence Earth’s radiative balance, having both warming and cooling effects. Though many aerosols reflect radiation, carbonaceous aerosols such as black carbon and certain organic carbon species known as brown carbon have the potential to warm the atmosphere by absorbing light. Black carbon absorbs light over the entire solar spectrum whereas brown carbon absorbs near-UV wavelengths and, to a lesser extent, visible light. In developing countries, such as India, where combustion sources are prolific, the influence of brown carbon on absorption may be significant. In order to better characterize brown carbon, we present experimental and modeled absorption properties of submicron aerosols measured in an urban Indian city (Kanpur). Brown carbon here is found to be fivefold more absorbing at 365 nm wavelength compared to previous studies. Results suggest ~30% of total absorption in Kanpur is attributed to brown carbon, with primary organic aerosols contributing more than secondary organics. We report the spectral brown carbon refractive indices along with an experimentally constrained estimate of the influence of aerosol mixing state on absorption. We conclude that brown carbon in Kanpur is highly absorbing in nature and that the mixing state plays an important role in light absorption from volatile species. PMID:27883083

  7. Three-photon absorption and nonlinear refraction of BaMgF4 in the ultraviolet region.

    PubMed

    Ma, Yanzhi; Chen, Junjie; Zheng, Yuanlin; Chen, Xianfeng

    2012-08-01

    The nonlinear refraction and nonlinear absorption phenomena are investigated in BaMgF(4) single crystal using the Z-scan technique in the ultraviolet region with a pulsed laser at 400 nm with 1 ps pulse duration. The remarkable nonlinear absorption behavior is identified to be three-photon absorption under the experimental conditions. In addition, both nonlinear refraction and nonlinear absorption have relatively large values and possess small anisotropy along three different crystallographic axes. The large values of nonlinear refractive index are demonstrated through the self-phase modulation effect.

  8. Towards a Negative Refractive Index in an Atomic System

    NASA Astrophysics Data System (ADS)

    Simmons, Zach; Brewer, Nick; Yavuz, Deniz

    2014-05-01

    The goal of our experiments is to obtain a negative index of refraction in the optical region of the spectrum using an atomic system. The concept of negative refraction, which was first predicted by Veselago more than four decades ago, has recently emerged as a very exciting field of science. Negative index materials exhibit many seemingly strange properties such as electromagnetic vectors forming a left-handed triad. A key potential application for these materials was discovered in 2000 when Pendry predicted that a slab with a negative refractive index can image objects with a resolution far better than the diffraction limit. Thus far, research in negative index materials has primarily focused on meta-materials. The fixed response and often large absorption of these engineered materials motivates our efforts to work in an atomic system. An atomic media offers the potential to be actively modified, for example by changing laser parameters, and can be tuned to cancel absorption. A doped crystal allows for high atomic densities compared to other atomic systems. So far we have identified a transition in such a material, Eu:YSO, as a candidate for these experiments and are performing spectroscopy on this material.

  9. Pyrene absorption can be a convenient method for probing critical micellar concentration (cmc) and indexing micellar polarity.

    PubMed

    Basu Ray, Gargi; Chakraborty, Indranil; Moulik, Satya P

    2006-02-01

    The critical micellar concentration (cmc) of both ionic and non-ionic surfactants can be conveniently determined from the measurements of UV absorption of pyrene in surfactant solution. The results on a number of surfactants have agreed with that realized from pyrene fluorescence measurements as well as that obtained following conductometric, tensiometric and calorimetric methods. The absorbance vs [surfactant] profiles for all the major UV spectral peaks of pyrene have been found to be sigmoidal in nature which were analyzed according to Sigmoidal-Boltzmann equation (SBE) to evaluate the cmcs of the studied surfactants. The difference between the initial and the final asymptotes (a(i) and a(f), respectively) of the sigmoidal profile, Delta a = (a(f)-a(i)) and the slope of the sigmoid, S(sig) have been observed to depend on the type of the surfactant. The Delta a has shown a linear correlation with the ratio of the fluorescence intensities of the first and the third vibronic peaks, I1/I3 of pyrene which is considered as a measure of the environmental polarity (herein micellar interior) of the probe (pyrene). Thus, Delta a values have the prospect for use as another index for the estimation of polarity of micellar interior.

  10. Experimental comparison between speech transmission index, rapid speech transmission index, and speech intelligibility index.

    PubMed

    Larm, Petra; Hongisto, Valtteri

    2006-02-01

    During the acoustical design of, e.g., auditoria or open-plan offices, it is important to know how speech can be perceived in various parts of the room. Different objective methods have been developed to measure and predict speech intelligibility, and these have been extensively used in various spaces. In this study, two such methods were compared, the speech transmission index (STI) and the speech intelligibility index (SII). Also the simplification of the STI, the room acoustics speech transmission index (RASTI), was considered. These quantities are all based on determining an apparent speech-to-noise ratio on selected frequency bands and summing them using a specific weighting. For comparison, some data were needed on the possible differences of these methods resulting from the calculation scheme and also measuring equipment. Their prediction accuracy was also of interest. Measurements were made in a laboratory having adjustable noise level and absorption, and in a real auditorium. It was found that the measurement equipment, especially the selection of the loudspeaker, can greatly affect the accuracy of the results. The prediction accuracy of the RASTI was found acceptable, if the input values for the prediction are accurately known, even though the studied space was not ideally diffuse.

  11. Influence of refractive index and solar concentration on optical power absorption in slabs

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1988-01-01

    The optical power absorbed by a slab at the focus of a parabolic dish concentrator is calculated. The calculations are plotted versus maximum angle of incidence of irradiation (which corresponds to solar concentration) with absorption coefficient as a parameter for several different indices of refraction that represent real materials.

  12. Is work engagement related to work ability beyond working conditions and lifestyle factors?

    PubMed

    Airila, Auli; Hakanen, Jari; Punakallio, Anne; Lusa, Sirpa; Luukkonen, Ritva

    2012-11-01

    To examine the associations of age, lifestyle and work-related factors, and particularly work engagement with the work ability index (WAI) and its sub-dimensions. Step-wise regression analysis with a sample of Finnish firefighters (n = 403) was used. The outcome variables were the WAI and its six sub-dimensions. The independent variables consisted of age, lifestyle variables (alcohol consumption, BMI, smoking, physical exercise, and sleep problems), working conditions (job demands, physical workload, supervisory relations, and task resources), and work engagement. The outcome variables and all the variables related to lifestyle, working conditions, and work engagement were measured in 2009. Work ability at baseline 10 years earlier was adjusted for in the models. Work engagement, age, physical exercise, sleep problems, and physical workload were associated with the WAI. All independent variables, except BMI and alcohol consumption, were associated with at least one sub-dimension of the WAI after controlling the baseline WAI. Lifestyle variables, working conditions, and work engagement were more strongly related to the subjective WAI sub-dimensions than to the two more objective WAI sub-dimensions. Work engagement was significantly associated with work ability even after adjusting for various factors, indicating its importance in promoting work ability. Other key factors for good work ability were frequent exercise, good sleep, non-smoking, low job demands, low physical workload, and high task resources. More specifically, this study suggests that in maintaining work ability, it is valuable not only to promote lifestyle factors or working conditions, but also to enhance employees' positive state of work engagement.

  13. Absorption Voltages and Insulation Resistance in Ceramic Capacitors with Cracks

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2016-01-01

    Time dependence of absorption voltages (Vabs) in different types of low-voltage X5R and X7R ceramic capacitors was monitored for a maximum duration of hundred hours after polarization. To evaluate the effect of mechanical defects on Vabs, cracks in the dielectric were introduced either mechanically or by thermal shock. The maximum absorption voltage, time to roll-off, and the rate of voltage decrease are shown to depend on the crack-related leakage currents and insulation resistance in the parts. A simple model that is based on the Dow equivalent circuit for capacitors with absorption has been developed to assess the insulation resistance of capacitors. Standard measurements of the insulation resistance, contrary to the measurements based on Vabs, are not sensitive to the presence of mechanical defects and fail to reveal capacitors with cracks. Index Terms: Ceramic capacitor, insulation resistance, dielectric absorption, cracking.

  14. Light absorption of organic aerosol from pyrolysis of corn stalk

    NASA Astrophysics Data System (ADS)

    Li, Xinghua; Chen, Yanju; Bond, Tami C.

    2016-11-01

    Organic aerosol (OA) can absorb solar radiation in the low-visible and ultra-violet wavelengths thereby modifying radiative forcing. Agricultural waste burning emits a large quantity of organic carbon in many developing countries. In this work, we improved the extraction and analysis method developed by Chen and Bond, and extended the spectral range of OC absorption. We examined light absorbing properties of primary OA from pyrolysis of corn stalk, which is a major type of agricultural wastes. Light absorption of bulk liquid extracts of OA was measured using a UV-vis recording spectrophotometer. OA can be extracted by methanol at 95%, close to full extent, and shows polar character. Light absorption of organic aerosol has strong spectral dependence (Absorption Ångström exponent = 7.7) and is not negligible at ultra-violet and low-visible regions. Higher pyrolysis temperature produced OA with higher absorption. Imaginary refractive index of organic aerosol (kOA) is 0.041 at 400 nm wavelength and 0.005 at 550 nm wavelength, respectively.

  15. Aerosol Absorption and Radiative Forcing

    NASA Technical Reports Server (NTRS)

    Stier, Philip; Seinfeld, J. H.; Kinne, Stefan; Boucher, Olivier

    2007-01-01

    We present a comprehensive examination of aerosol absorption with a focus on evaluating the sensitivity of the global distribution of aerosol absorption to key uncertainties in the process representation. For this purpose we extended the comprehensive aerosol-climate model ECHAM5-HAM by effective medium approximations for the calculation of aerosol effective refractive indices, updated black carbon refractive indices, new cloud radiative properties considering the effect of aerosol inclusions, as well as by modules for the calculation of long-wave aerosol radiative properties and instantaneous aerosol forcing. The evaluation of the simulated aerosol absorption optical depth with the AERONET sun-photometer network shows a good agreement in the large scale global patterns. On a regional basis it becomes evident that the update of the BC refractive indices to Bond and Bergstrom (2006) significantly improves the previous underestimation of the aerosol absorption optical depth. In the global annual-mean, absorption acts to reduce the shortwave anthropogenic aerosol top-of-atmosphere (TOA) radiative forcing clear-sky from -0.79 to -0.53 W m(sup -2) (33%) and all-sky from -0.47 to -0.13W m(sup -2 (72%). Our results confirm that basic assumptions about the BC refractive index play a key role for aerosol absorption and radiative forcing. The effect of the usage of more accurate effective medium approximations is comparably small. We demonstrate that the diversity in the AeroCom land-surface albedo fields contributes to the uncertainty in the simulated anthropogenic aerosol radiative forcings: the usage of an upper versus lower bound of the AeroCom land albedos introduces a global annual-mean TOA forcing range of 0.19W m(sup -2) (36%) clear-sky and of 0.12W m(sup -2) (92%) all-sky. The consideration of black carbon inclusions on cloud radiative properties results in a small global annual-mean all-sky absorption of 0.05W m(sup -2) and a positive TOA forcing perturbation of 0

  16. Impact of material absorption on supercontinuum generation in liquid core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Nithyanandan, K.; Raja, Vasantha Jayakantha; Uthayakumar, T.; Porsezian, K.

    2013-06-01

    The impact of material absorption on supercontinuum generation (SCG) in liquid core photonic crystal fiber (LCPCF) is presented. While PCFs with cores made from different glasses are well studied in previous works with saturable nonlinear response (SNL), in this paper, it is planned to investigate the dynamics of nonlinear processes of supercontinuum generation in high-index fiber with material absorption to understand the physical phenomena of pulse propagation.

  17. Evaluation of intestinal metabolism and absorption using the Ussing chamber system equipped with intestinal tissue from rats and dogs.

    PubMed

    Miyake, Masateru; Kondo, Satoshi; Koga, Toshihisa; Yoda, Noriaki; Nakazato, Satoru; Emoto, Chie; Mukai, Tadashi; Toguchi, Hajime

    2018-01-01

    The purpose of this study was to evaluate the intestinal metabolism and absorption in a mini-Ussing chamber equipped with animal intestinal tissues, based on the transport index (TI). TI value was defined as the sum of drug amounts transported to the basal-side component (X corr ) and drug amounts accumulated in the tissue (T corr ), which are normalized by AUC of a drug in the apical compartment, as an index for drug absorption. Midazolam was used as a test compound for the evaluation of intestinal metabolism and absorption. The metabolite formulation of midazolam was observed in both rats and dogs. Ketoconazole inhibited the intestinal metabolism of midazolam in rats and improved its intestinal absorption to a statistically significant extent. Therefore, the mini-Ussing chamber, equipped with animal intestinal tissues, showed potential to use the evaluation of the intestinal metabolism and absorption, including the assessment of species differences. Copyright © 2017. Published by Elsevier B.V.

  18. Oceanic response to changes in the WAIS and astronomical forcing during the MIS31 superinterglacial

    NASA Astrophysics Data System (ADS)

    Justino, Flavio; Lindemann, Douglas; Kucharski, Fred; Wilson, Aaron; Bromwich, David; Stordal, Frode

    2017-09-01

    Marine Isotope Stage 31 (MIS31, between 1085 and 1055 ka) was characterized by higher extratropical air temperatures and a substantial recession of polar glaciers compared to today. Paleoreconstructions and model simulations have increased the understanding of the MIS31 interval, but questions remain regarding the role of the Atlantic and Pacific oceans in modifying the climate associated with the variations in Earth's orbital parameters. Multi-century coupled climate simulations, with the astronomical configuration of the MIS31 and modified West Antarctic Ice Sheet (WAIS) topography, show an increase in the thermohaline flux and northward oceanic heat transport (OHT) in the Pacific Ocean. These oceanic changes are driven by anomalous atmospheric circulation and increased surface salinity in concert with a stronger meridional overturning circulation (MOC). The intensified northward OHT is responsible for up to 85 % of the global OHT anomalies and contributes to the overall reduction in sea ice in the Northern Hemisphere (NH) due to Earth's astronomical configuration. The relative contributions of the Atlantic Ocean to global OHT and MOC anomalies are minor compared to those of the Pacific. However, sea ice changes are remarkable, highlighted by decreased (increased) cover in the Ross (Weddell) Sea but widespread reductions in sea ice across the NH.

  19. Multiple dimensions of work-related risk factors and their relationship to work ability among industrial workers in Iran.

    PubMed

    Mokarami, Hamidreza; Mortazavi, Seyed Bagher; Asgari, Ali; Choobineh, Alireza; Stallones, Lorann

    2017-09-01

    The present study was designed to investigate the simultaneous effects of physical, psychosocial and other work-related risk factors on the work ability index (WAI) score among industrial workers. This study used a cross-sectional design with a questionnaire survey. A total of 280 workers were included in the study. Data were collected using three questionnaires including the Persian version of the WAI, the Persian version of the job content questionnaire and an author-developed measure (to assess work-related factors, health-related factors and socio-demographic characteristics). The majority of the participants were young, but they had poor WAI scores (mean 37.3 ± 6.4) and 44.3% of them had poor or moderate work ability. Occupational accidents and injuries were found to be the strongest predictors of WAI scores. Additionally, there was a strong association between WAI scores and supervisor support, skill discretion, occupational training, sleep quality, work nature and educational level. Intervention programs should focus on improving supervisor support, sleep quality, job skills and knowledge and on decreasing physical and mental work demands. Additionally, implementing a comprehensive occupational health and ergonomics program for controlling and reducing hazardous working environments and occupational injury rates should be considered.

  20. Effect of feed composition, moisture content and extrusion temperature on extrudate characteristics of yam-corn-rice based snack food.

    PubMed

    Seth, Dibyakanta; Badwaik, Laxmikant S; Ganapathy, Vijayalakshmi

    2015-03-01

    Blends of yam, rice and corn flour were processed in a twin-screw extruder. Effects of yam flour (10-40 %), feed moisture content (12-24 %) and extruder barrel temperature (100-140 °C) on the characteristics of the dried extrudates was investigated using a statistical technique response surface methodology (RSM). Radial expansion ratio differed significantly (p ≤ 0.05) with change in all the independent variables. Highest expansion (3.97) was found at lowest moisture content (12 %) and highest barrel temperature (140 °C). Increased yam flour level decreased the expansion ratio significantly. Water absorption index (WAI) increased significantly with increase of all variables. However, water solubility index (WSI) did not change with change in yam flour percent. Hardness of extrudates that varied from 3.86 to 6.94 N was positively correlated with yam flour level and feed moisture content, however it decreased significantly (p ≤ 0.001) with increase of barrel temperature. Yam percent of 15.75 with feed moisture and barrel temperature at 12.00 % and 140 °C respectively gave an optimized product of high desirability (> 0.90) with optimum responses of 3.29 expansion ratio, 5.64 g/g dry solid water absorption index, 30.39 % water solubility index and 3.86 N hardness. The predicted values registered non-significant (p < 0.10) differences from the experimental results. Further study would include the sensory properties enhancement of extruded snacks and little emphasis on the chemistry of interaction between different components.

  1. Relative sensitivity of Normalized Difference Vegetation Index (NDVI) and Microwave Polarization Difference Index (MPDI) for vegetation and desertification monitoring

    NASA Technical Reports Server (NTRS)

    Becker, Francois; Choudhury, Bhaskar J.

    1988-01-01

    A simple equation relating the Microwave Polarization Difference Index (MPDI) and the Normalized Difference Vegetation Index (NDVI) is proposed which represents well data obtained from Nimbus 7/SMMR at 37 GHz and NOAA/AVHRR Channels 1 and 2. It is found that there is a limit which is characteristic of a particular type of cover for which both indices are equally sensitive to the variation of vegetation, and below which MPDI is more efficient than NDVI. The results provide insight into the relationship between water content and chlorophyll absorption at pixel size scales.

  2. Therapeutic alliance in dietetic practice for weight loss: Insights from health coaching.

    PubMed

    Nagy, Annaliese; McMahon, Anne; Tapsell, Linda; Deane, Frank; Arenson, Danielle

    2018-02-13

    The psychological construct of 'therapeutic alliance' can be used to better understand the effectiveness of consultations, particularly goal setting for weight management. We analysed audio-recorded health coaching sessions during a weight loss trial to explore relationships between therapeutic alliance and various contextual factors. Audio recordings of 50 health coaching sessions were analysed. After assessing fidelity to the protocol, therapeutic alliance was measured using an adapted Working Alliance Inventory Observer-rated Short Version (WAI-O-S), and examined by (i) identifying relationships between contextual factors and WAI-O-S scores (Spearman's coefficients); (ii) testing the impact of preparatory exercises and body mass index on WAI-O-S scores (one-way analysis of variance and least-squared differences tests) and (iii) comparing differences in WAI-O-S scores based on relationship status, gender and follow-up session completion (independent samples t-tests). Fidelity was high (mean 88%). WAI-O-S total scores ranged from 55 to 70 (out of 84). Session duration was significantly correlated with WAI-O-S component of 'Bond' (r = 0.42, P = 0.002). Those who completed preparatory exercises had significantly higher total WAI-O-S scores, 'Goal' and 'Task' scores. Participants who completed the follow-up session scored significantly higher for 'Goal' compared to no follow-up. Spending more time in a session appears related to increased bonding, a key component of therapeutic alliance. Preparatory work may help build therapeutic alliance and agreement on goals appears to influence follow-up completion. These exploratory findings provide directions for research addressing the professional relationship in dietetic consultations for weight loss. © 2018 Dietitians Association of Australia.

  3. Enrichment of extruded snack products with coproducts from chestnut mushroom (Agrocybe aegerita) production: interactions between dietary fiber, physicochemical characteristics, and glycemic load.

    PubMed

    Brennan, Margaret A; Derbyshire, Emma; Tiwari, Brijesh K; Brennan, Charles S

    2012-05-02

    Mushrooms are a common vegetable product that have also been linked to pharmaceutical and medicinal uses. However, the production of the fruiting bodies of mushrooms results in a large quantity of food waste in the form of spent compost. Hyphae and the base of fruit bodies from Agrocybe aegerita were retrieved from spent mushroom compost and refined as a freeze-dried powder. This fiber-rich ingredient was used in the manufacture of ready-to-eat extruded cereal snack products. Inclusions rates were 0, 5, 10, and 15% w/w replacement levels for wheat flour from a control recipe. Inclusion of mushroom coproduct material (MCM) was significantly correlated to increased product expansion (r = 0.848) and density (r = 0.949) but negatively correlated to water absorption index (WAI; r = -0.928) and water solubility index (WSI; r = -0.729). Fiber content could not be correlated to differences in pasting properties of extruded snacks even though snack products with MCM showed significantly lower final viscosity values compared to the control. The potential glycemic response of foods was significantly lowered by including MCM (p < 0.05) with a negative correlation between fiber content and overall AUC following a standardized in vitro digestion method (r = -0.910). Starch content, WAI, and WSI were positively correlated to AUC of extruded snacks (r = 0.916, 0.851, and 0.878. respectively). The results illustrate a reduction in the potential glycemic response from including 5% (w/w) of MCM in extruded snacks exceeds 20%. Thus, the incorporation of MCM in ready-to-eat snack foods may be of considerable interest to the food industry in trying to regulate the glycemic response of foods.

  4. Measurement of Scattering and Absorption Cross Sections of Dyed Microspheres

    PubMed Central

    Gaigalas, Adolfas K; Choquette, Steven; Zhang, Yu-Zhong

    2013-01-01

    Measurements of absorbance and fluorescence emission were carried out on aqueous suspensions of polystyrene (PS) microspheres with a diameter of 2.5 µm using a spectrophotometer with an integrating sphere detector. The apparatus and the principles of measurements were described in our earlier publications. Microspheres with and without green BODIPY@ dye were measured. Placing the suspension inside an integrating sphere (IS) detector of the spectrophotometer yielded (after a correction for fluorescence emission) the absorbance (called A in the text) due to absorption by BODIPY@ dye inside the microsphere. An estimate of the absorbance due to scattering alone was obtained by subtracting the corrected BODIPY@ dye absorbance (A) from the measured absorbance of a suspension placed outside the IS detector (called A1 in the text). The absorption of the BODIPY@ dye inside the microsphere was analyzed using an imaginary index of refraction parameterized with three Gaussian-Lorentz functions. The Kramer-Kronig relation was used to estimate the contribution of the BODIPY@ dye to the real part of the microsphere index of refraction. The complex index of refraction, obtained from the analysis of A, was used to analyze the absorbance due to scattering ((A1- A) in the text). In practice, the analysis of the scattering absorbance, A1-A, and the absorbance, A, was carried out in an iterative manner. It was assumed that A depended primarily on the imaginary part of the microsphere index of refraction with the other parameters playing a secondary role. Therefore A was first analyzed using values of the other parameters obtained from a fit to the absorbance due to scattering, A1-A, with the imaginary part neglected. The imaginary part obtained from the analysis of A was then used to reanalyze A1-A, and obtain better estimates of the other parameters. After a few iterations, consistent estimates were obtained of the scattering and absorption cross sections in the wavelength region 300

  5. Complex refractive index of Martian dust - Mariner 9 ultraviolet observations

    NASA Technical Reports Server (NTRS)

    Pang, K.; Ajello, J. M.; Hord, C. W.; Egan, W. G.

    1976-01-01

    Mariner 9 ultraviolet spectrometer observations of the 1971 dust clouds obscuring the surface of Mars have been analyzed by matching the observed dust phase function with Mie scattering calculations for size distributions of homogeneous and isotropic material. Preliminary results indicate an effective particle radius of not less than 0.2. The real component of the index of refraction is not less than 1.8 at both 268 and 305 nm; corresponding values for the imagery component are 0.02 and 0.01. These values are consistent with those found by Mead (1970) for the visible and near-visible wavelengths. The refractive index and the absorption coefficient increase rapidly with decreasing wavelength in going from the visible to the ultraviolet, indicating the presence of an ultraviolet absorption band which may shield organisms from ultraviolet irradiation.

  6. Resonant laser printing of structural colors on high-index dielectric metasurfaces

    PubMed Central

    Zhu, Xiaolong; Yan, Wei; Levy, Uriel; Mortensen, N. Asger; Kristensen, Anders

    2017-01-01

    Man-made structural colors, which originate from resonant interactions between visible light and manufactured nanostructures, are emerging as a solution for ink-free color printing. We show that non-iridescent structural colors can be conveniently produced by nanostructures made from high-index dielectric materials. Compared to plasmonic analogs, color surfaces with high-index dielectrics, such as germanium (Ge), have a lower reflectance, yielding a superior color contrast. Taking advantage of band-to-band absorption in Ge, we laser-postprocess Ge color metasurfaces with morphology-dependent resonances. Strong on-resonance energy absorption under pulsed laser irradiation locally elevates the lattice temperature (exceeding 1200 K) in an ultrashort time scale (1 ns). This forms the basis for resonant laser printing, where rapid melting allows for surface energy–driven morphology changes with associated modification of color appearance. Laser-printable high-index dielectric color metasurfaces are scalable to a large area and open a new paradigm for printing and decoration with nonfading and vibrant colors. PMID:28508062

  7. Fabrication of refractive index distributions in polymer using a photochemical reaction

    NASA Astrophysics Data System (ADS)

    Kada, Takeshi; Obara, Atsushi; Watanabe, Toshiyuki; Miyata, Seizo; Liang, Chuan Xin; Machida, Hideaki; Kiso, Koichi

    2000-01-01

    We demonstrate that a photochemical reaction can create various distributions of refractive index in polymer. When the polymer containing a photochemically active material is irradiated by UV light, the photochemical reaction which breaks the π-conjugated system in the material and decreases its linear polarizability can reduce refractive index of the polymer. We prepared a PMMA film added DMAPN ((4-N,N-dimethylaminophenyl)-N'-phenylnitrone) with a rate of 23 wt % by use of spin coating. Electronic structural change of DMAPN and refractive indices of the film before and after UV irradiation were evaluated by UV absorption spectra and m-line method, respectively. The UV irradiation decreased λmax at 380 nm in the absorption spectra, which is attributed to nitrone, and the refractive indices exponentially with irradiation time. The change of refractive indices reached 0.028. The refractive index profile upon depth of the film was investigated by measuring refractive indices of stacked DMAPN/PMMA films. When UV with a power of 10.7 mW/cm2 irradiated upon three stacked DMAPN/PMMA films for 35 s, variation of the refractive index change showed a quadratic profile. The refractive index profile with various irradiation time can be accounted with the combination of the chemical kinetics with the steady state approximation and Lambert-Beer's law. Thus, the photochemical reaction can be used to control the refractive index distribution in polymer.

  8. Measurement of Absorption Coefficient of Paraformaldehyde and Metaldehyde with Terahertz Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Xia, T.; Chen, Q.; Sun, Q.; Deng, Y.; Wang, C.

    2018-03-01

    The characteristic absorption spectra of paraformaldehyde and metaldehyde in the terahertz frequency region are obtained by terahertz time-domain spectroscopy (THz-TDS). In order to reduce the absorption of terahertz (THz) wave by water vapor in the air and the background noise, the measurement system was filled with dry air and the measurements were conducted at the temperature of 24°C. Meanwhile, the humidity was controlled within 10% RH. The THz frequency domain spectra of samples and their references from 0 to 2.5 THz were analyzed via Fourier transform. The refractive index and absorption coefficients of the two aldehydes were calculated by the model formulas. From 0.1 to 2.5 THz, there appear two weak absorption peaks at 1.20 and 1.66 THz in the absorption spectra of paraformaldehyde. Only one distinct absorption peak emerges at 1.83 THz for metaldehyde. There are significant differences between the terahertz absorption coefficients of paraformaldehyde and metaldehyde, which can be used as "fingerprints" to identify these substances. Furthermore, the relationship between the average absorption coefficients and mass concentrations was investigated and the average absorption coefficient-mass concentration diagrams of paraformaldehyde and metaldehyde were shown. For paraformaldehyde, there is a linear relationship between the average absorption coefficient and the natural logarithm of mass concentration. For metaldehyde, there exists a simpler linear relationship between the average absorption coefficient and the mass concentration. Because of the characteristics of THz absorption of paraformaldehyde and metaldehyde, the THz-TDS can be applied to the qualitative and quantitative detection of the two aldehydes to reduce the unpredictable hazards due to these substances.

  9. Measurement of the aerosol absorption coefficient with the nonequilibrium process

    NASA Astrophysics Data System (ADS)

    Li, Liang; Li, Jingxuan; Bai, Hailong; Li, Baosheng; Liu, Shanlin; Zhang, Yang

    2018-02-01

    On the basis of the conventional Jamin interferometer,the improved measuring method is proposed that using a polarization type reentrant Jamin interferometer measures atmospheric aerosol absorption coefficient under the photothermal effect.The paper studies the relationship between the absorption coefficient of atmospheric aerosol particles and the refractive index change of the atmosphere.In Matlab environment, the variation curves of the output voltage of the interferometer with different concentration aerosol samples under stimulated laser irradiation were plotted.Besides, the paper also studies the relationship between aerosol concentration and the time required for the photothermal effect to reach equilibrium.When using the photothermal interferometry the results show that the time required for the photothermal effect to reach equilibrium is also increasing with the increasing concentration of aerosol particles,the absorption coefficient and time of aerosol in the process of nonequilibrium are exponentially changing.

  10. Thin-film limit formalism applied to surface defect absorption.

    PubMed

    Holovský, Jakub; Ballif, Christophe

    2014-12-15

    The thin-film limit is derived by a nonconventional approach and equations for transmittance, reflectance and absorptance are presented in highly versatile and accurate form. In the thin-film limit the optical properties do not depend on the absorption coefficient, thickness and refractive index individually, but only on their product. We show that this formalism is applicable to the problem of ultrathin defective layer e.g. on a top of a layer of amorphous silicon. We develop a new method of direct evaluation of the surface defective layer and the bulk defects. Applying this method to amorphous silicon on glass, we show that the surface defective layer differs from bulk amorphous silicon in terms of light soaking.

  11. Significance of Ca-soap formation for calcium absorption in the rat.

    PubMed Central

    Gacs, G; Barltrop, D

    1977-01-01

    The significance of calcium soap formation in the inhibition of calcium absorption has been studied in rats. 47Ca labelled soaps of fatty acids were introduced into the duodenum and the absorption of calcium measured after four hours in a whole body counter. The absorption of calcium was inversely correlated with the chain length of the fatty acid varying from 1% for Ca-stearate to 60% for Ca-hexanoate. Increasing the degree of unsaturation of the fatty acid was accompanied by increased calcium absorption. The availability of calcium for absorption from the soaps was correlated with their solubility in 1% aqueous Na-tauroglycocholate. The percentages of calcium as soap in the small intestine and the faeces after intragastric administration of calcium and fats were similar, which suggests that the faecal content of calcium soaps is an index of intestinal soap formation. Soap formation was negligible when CaCl2 was given with tristearate, triolaeate, or tridecanoate and no depression of calcium absorption was observed. Calcium absorption was markedly impaired by the addition of phosphates at a Ca/P ratio of 1:1 irrespective of the presence of neutral fats. Stearic acid resulted in significant soap formation and reduced calcium absorption. The degree of Ca-soap formation and the inhibition of calcium absorption were well correlated. The results suggest that, although calcium soap formation may markedly depress calcium absorption in the rat, no significant soap formation takes place when fats are given in the form of triglycerides. PMID:838405

  12. Broadband infrared absorption enhancement by electroless-deposited silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Gritti, Claudia; Raza, Søren; Kadkhodazadeh, Shima; Kardynal, Beata; Malureanu, Radu; Mortensen, N. Asger; Lavrinenko, Andrei V.

    2017-01-01

    Decorating semiconductor surfaces with plasmonic nanoparticles (NPs) is considered a viable solution for enhancing the absorptive properties of photovoltaic and photodetecting devices. We propose to deposit silver NPs on top of a semiconductor wafer by a cheap and fast electroless plating technique. Optical characterization confirms that the random array of electroless-deposited NPs improves absorption by up to 20% in a broadband of near-infrared frequencies from the bandgap edge to 2000 nm. Due to the small filling fraction of particles, the reflection in the visible range is practically unchanged, which points to the possible applications of such deposition method for harvesting photons in nanophotonics and photovoltaics. The broadband absorption is a consequence of the resonant behavior of particles with different shapes and sizes, which strongly localize the incident light at the interface of a high-index semiconductor substrate. Our hypothesis is substantiated by examining the plasmonic response of the electroless-deposited NPs using both electron energy loss spectroscopy and numerical calculations.

  13. Terahertz Absorption by Cellulose: Application to Ancient Paper Artifacts

    NASA Astrophysics Data System (ADS)

    Peccianti, M.; Fastampa, R.; Mosca Conte, A.; Pulci, O.; Violante, C.; Łojewska, J.; Clerici, M.; Morandotti, R.; Missori, M.

    2017-06-01

    Artifacts made of cellulose, such as ancient documents, pose a significant experimental challenge in the terahertz transmission spectra interpretation due to their small optical thickness. In this paper, we describe a method to recover the complex refractive index of cellulose fibers from the terahertz transmission data obtained on single freely standing paper sheets in the (0.2-3.5)-THz range. By using our technique, we eliminate Fabry-Perot effects and recover the absorption coefficient of the cellulose fibers. The obtained terahertz absorption spectra are explained in terms of absorption peaks of the cellulose crystalline phase superimposed to a background contribution due to a disordered hydrogen-bond network. The comparison between the experimental spectra with terahertz vibrational properties simulated by density-functional-theory calculations confirms this interpretation. In addition, evident changes in the terahertz absorption spectra are produced by natural and artificial aging on paper samples, whose final stage is characterized by a spectral profile with only two peaks at about 2.1 and 3.1 THz. These results can be used to provide a quantitative assessment of the state of preservation of cellulose artifacts.

  14. Refractive index dependence of L3 photonic crystal nano-cavities.

    PubMed

    Adawi, A M; Chalcraft, A R; Whittaker, D M; Lidzey, D G

    2007-10-29

    We model the optical properties of L3 photonic crystal nano-cavities as a function of the photonic crystal membrane refractive index n using a guided mode expansion method. Band structure calculations revealed that a TE-like full band-gap exists for materials of refractive index as low as 1.6. The Q-factor of such cavities showed a super-linear increase with refractive index. By adjusting the relative position of the cavity side holes, the Q-factor was optimised as a function of the photonic crystal membrane refractive index n over the range 1.6 to 3.4. Q-factors in the range 3000-8000 were predicted from absorption free materials in the visible range with refractive index between 2.45 and 2.8.

  15. Nonlinearly enhanced linear absorption under filamentation in mid-infrared (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Shipilo, Daniil; Panov, Nicolay; Andreeva, Vera; Kosareva, Olga G.; Saletski, Alexander M.; Xu, Huai-Liang; Polynkin, Pavel

    2017-05-01

    The mid-infrared OPCPA-based laser facilities have recently reached the critical power for self-focusing in air [1]. This ensures the demonstration of the major difference between the mid- and near-infrared filamentation in air: the odd optical harmonics, harshly suppressed by the material dispersion and phase-mismatch in the near-infrared (800 nm), gain reliable energies in the mid-infrared (3.9 µm) filament [1,2]. Another issue that makes mid-infrared filamentation different from the near-infrared one is a lot of molecular vibrational lines belonging to atmospheric constituents and located in the mid-infrared range [3]. As the result the mid-infrared region of interest becomes subdivided into the bands of normal and anomalous dispersion, the former of which leads to the pulse splitting in temporal domain, while the latter produces the confined light bullet. We simulate the 3.9-µm filamentation using Forward Maxwell equation. We include the tunnel ionization and transient photocurrent as the collapse arresting mechanism, which balances dynamically the instantaneous third-order medium response (similarly to 800-nm filamentation). The key feature that allows us to quantify the losses due to absorption bands is the accurate account of the complex linear absorption index. The absorption index obtained from Mathar model [3] is interpolated to the fine frequency grid (step of about 0.1 THz), and the refractive index is matched according to Kramers-Krönig relations [4]. If the initial Gaussian pulse has a center wavelength of 3.9 µm and a duration of 80 fs FWHM, the energy loss in the carbon dioxide (CO_2) absorption band at 4.3 µm is about 1% in the linear propagation regime. But when we take the 80-mJ pulse (about 3 critical powers for self-focusing), the Kerr-induced spectral broadening develops significantly before the clamping level of intensity is reached. In the collimated beam geometry about 2% of the initial pulse energy is absorbed on the CO_2 band before

  16. A quantum cascade laser-based Mach-Zehnder interferometer for chemical sensing employing molecular absorption and dispersion

    NASA Astrophysics Data System (ADS)

    Hayden, Jakob; Hugger, Stefan; Fuchs, Frank; Lendl, Bernhard

    2018-02-01

    We employ a novel spectroscopic setup based on an external cavity quantum cascade laser and a Mach-Zehnder interferometer to simultaneously record spectra of absorption and dispersion of liquid samples in the mid-infrared. We describe the theory underlying the interferometric measurement and discuss its implications for the experiment. The capability of simultaneously recording a refractive index and absorption spectrum is demonstrated for a sample of acetone in cyclohexane. The recording of absorption spectra is experimentally investigated in more detail to illustrate the method's capabilities as compared to direct absorption spectroscopy. We find that absorption signals are recorded with strongly suppressed background, but with smaller absolute sensitivity. A possibility of optimizing the setup's performance by unbalancing the interferometer is presented.

  17. Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes

    PubMed Central

    2015-01-01

    We study one-, two-, three-, four-, and five-photon absorption of three centrosymmetric molecules using density functional theory. These calculations are the first ab initio calculations of five-photon absorption. Even- and odd-order absorption processes show different trends in the absorption cross sections. The behavior of all even- and odd-photon absorption properties shows a semiquantitative similarity, which can be explained using few-state models. This analysis shows that odd-photon absorption processes are largely determined by the one-photon absorption strength, whereas all even-photon absorption strengths are largely dominated by the two-photon absorption strength, in both cases modulated by powers of the polarizability of the final excited state. We demonstrate how to selectively enhance a specific multiphoton absorption process. PMID:26120588

  18. Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes.

    PubMed

    Friese, Daniel H; Bast, Radovan; Ruud, Kenneth

    2015-05-20

    We study one-, two-, three-, four-, and five-photon absorption of three centrosymmetric molecules using density functional theory. These calculations are the first ab initio calculations of five-photon absorption. Even- and odd-order absorption processes show different trends in the absorption cross sections. The behavior of all even- and odd-photon absorption properties shows a semiquantitative similarity, which can be explained using few-state models. This analysis shows that odd-photon absorption processes are largely determined by the one-photon absorption strength, whereas all even-photon absorption strengths are largely dominated by the two-photon absorption strength, in both cases modulated by powers of the polarizability of the final excited state. We demonstrate how to selectively enhance a specific multiphoton absorption process.

  19. Approaching total absorption of graphene strips using a c-Si subwavelength periodic membrane

    NASA Astrophysics Data System (ADS)

    Sang, Tian; Wang, Rui; Li, Junlang; Zhou, Jianyu; Wang, Yueke

    2018-04-01

    Approaching total absorption of graphene strips at near infrared using a crystalline-silicon (c-Si) subwavelength periodic membrane (SPM) is presented. The absorption in graphene strips in a c-Si SPM is enhanced by a resonant tip, which is resulted from the coupling between the guided mode and the radiation mode through symmetry breaking of the structure at near-normal incidence. The enhancement of the electric field intensity is increased 1939 times and the group velocity of light is decreased to 3.55 ×10-4c at resonance, and 99.3% absorption in graphene strips can be achieved by critical coupling at the incident angle of 2°. High absorption of the graphene strips can be maintained as the etching thickness, the strip width, and the period are altered. When this type of c-Si SPM with graphene strips is used in refractive index sensors, it shows excellent sensing properties due to its stable near-unity absorption.

  20. Investigation of a pressure-dependent refractive index of germanium film with an optical fiber film sensor.

    PubMed

    Yuan, Dongxu; Gao, Hongyun; Chen, Hao; Li, Min

    2018-02-01

    The refractive index of Ge is found in decline with applied pressure at a specific wavelength in the absorption region below 1900 nm, where the absorption coefficient rises dramatically with decreased wavelength. In this paper, we use a Ge-coated fiber optic probe to demonstrate quantitatively that the downward trend in the refractive index to increasing pressure matches the theoretically simulated optical properties of Ge with a measurement error of 1.03×10 -3 in the refractive index, which is further calculated within the framework of density functional theory with local density approximation. For the first time, to the best of our knowledge, both theoretical and experimental results prove that the refractive index reduces linearly with a gradient of -3.30×10 -4 /MPa as the pressure increases from 0 to 20 MPa.

  1. Uncertainty budgets for liquid waveguide CDOM absorption measurements.

    PubMed

    Lefering, Ina; Röttgers, Rüdiger; Utschig, Christian; McKee, David

    2017-08-01

    Long path length liquid waveguide capillary cell (LWCC) systems using simple spectrometers to determine the spectral absorption by colored dissolved organic matter (CDOM) have previously been shown to have better measurement sensitivity compared to high-end spectrophotometers using 10 cm cuvettes. Information on the magnitude of measurement uncertainties for LWCC systems, however, has remained scarce. Cross-comparison of three different LWCC systems with three different path lengths (50, 100, and 250 cm) and two different cladding materials enabled quantification of measurement precision and accuracy, revealing strong wavelength dependency in both parameters. Stable pumping of the sample through the capillary cell was found to improve measurement precision over measurements made with the sample kept stationary. Results from the 50 and 100 cm LWCC systems, with higher refractive index cladding, showed systematic artifacts including small but unphysical negative offsets and high-frequency spectral perturbations due to limited performance of the salinity correction. In comparison, the newer 250 cm LWCC with lower refractive index cladding returned small positive offsets that may be physically correct. After null correction of measurements at 700 nm, overall agreement of CDOM absorption data at 440 nm was found to be within 5% root mean square percentage error.

  2. Refractive Index and Scattering Effects on Radiative Behavior of a Semitransparent Layer

    NASA Technical Reports Server (NTRS)

    Spuckler, C. M.; Siegel, R.

    1993-01-01

    Heat transfer characteristics are analyzed for a plane layer of semitransparent material with refractive index not less than 1. Energy transfer in the material is by conduction, emission, absorption, and isotropic scattering. Each side of the layer is heated by radiation and convection. For a refractive index larger than unity, there is internal reflection of some of the energy within the layer. This, coupled with scattering, has a substantial effect on distributing energy across the layer and altering the temperature distribution from when the refractive index is unity. The effect of scattering is examined by comparisons with results from an earlier paper for an absorbing layer. Results are given for a gray medium with a scattering albedo up to 0.999, and for a two-band spectral variation of the albedo with one band having low absorption. Radiant energy leaving the surface as a result of emission and scattering was examined to determine if it could be used to accurately indicate the surface temperature.

  3. Nonlinear refraction and two-photon absorption in dense 2Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses

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

    Paramesh, Gadige; Varma, K. B. R.

    2012-06-05

    High density transparent glasses (7.86 g/cc) were fabricated in the 2Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} (BBO) system. Optical band gap of the obtained glasses was found to be 2.6eV. The refractive index measured for these glasses was 2.25{+-}0.05 at {lambda}=543 nm. Nonlinear refraction and absorption studies were carried out on the BBO glasses using z-scan technique at {lambda}=532 nm of 10 ns pulse width. The nonlinear refractive index obtained was n{sub 2}=12.1x10{sup -14} cm{sup 2}/W and nonlinear absorption coefficient was {beta}=15.2 cm/GW. The n{sub 2} and {beta} values of the BBO glasses were large compared to the other reported highmore » index bismuth based oxide glass systems in the literature. These were attributed to the high density, high linear refractive index, low band gap and two photon absorption associated with these glasses. The electronic origin of large nonlinearities was discussed based on bond-orbital theory.« less

  4. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    PubMed

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  5. Work ability of Chinese migrant workers: the influence of migration characteristics.

    PubMed

    Han, Lu; Shi, Leiyu; Lu, Liming; Ling, Li

    2014-04-13

    Migrant workers have become a vital labor supply to China's economy. Their migration process and work conditions may influence their health and work ability. The work ability of migrant workers in China and the influence of the migration process on work ability have not been explored extensively in previous studies. The objective of this study is to evaluate the association of migration characteristics and work-related factors with work ability among migrant workers in the Pearl River Delta. In this cross-sectional survey, the study population consisted of 907 migrant workers from ten factories in the Pearl River Delta who were exposed to organic solvents during work. The primary dependent variable of the study was work ability, measured by the Work Ability Index (WAI). The independent variables were individual characteristics, migration characteristics, and work-related factors. Logistic regression models were used to determine the influence of different factors on work ability and three dimensions of WAI. The result shows that among migration characteristics, social support was significantly associated with all three dimensions of the work ability index. Permanent migration intention and longer length of migration were negatively associated with the mental resource dimension of WAI. WAI was also influenced by individual and work-related factors. The findings of this study suggest that expanding migrants' social networks and social support systems in their work place or living community, (i.e. expanding the functions of labor unions) would be an effective way to improve migrant workers' work ability. Improving of migrant workers' physical and psychosocial related work environments would also increase their work ability.

  6. Peculiarities of light absorption by spherical microcapsules

    NASA Astrophysics Data System (ADS)

    Geints, Yurii E.; Panina, Ekaterina K.; Zemlyanov, Alexander A.

    2018-04-01

    Optical radiation absorption in the poly-layer spherical microparticles simulating the inorganic/organic polyshell absorbing microcapsules is considered. With the aim of the finite-difference time-domain technique, the spatial distribution of the absorbed light power in microcapsules of various sizes and internal structure is numerically calculated. For the purpose of light absorption enhancement, we have engineered the optimal structure of a capsule consisting of a strong-refracting transparent outer coating and an absorbing layer which covers a liquid core. The proposed microcapsule prototype provides for a manifold increase in the absorbed light power density in comparison with the usual single-layer absorbing capsule. We show that for light-wavelengths-scaled microcapsules it is optimal to use a material with the refractive index larger than two as an outer shell, for example, titanium dioxide (TiO2). The highest values of the absorbed power density can be obtained in microcapsules with absorbing shell thickness of approximately a tenth of a laser wavelength. When laser radiation is scattered by a dimer constituted by two identical absorbing microcapsules the absorbed power density can be maximized by the choosing of proper dimer spatial configuration. In the case of strongly absorbing particles, the absorption maximum corresponds to a shift of the capsules to a distance of about their diameter, and in the case of weakly absorbing particles the absorption is maximal when particles are in geometrical shades of each other.

  7. Occupational stress perception and its potential impact on work ability.

    PubMed

    Yong, Mei; Nasterlack, Michael; Pluto, Rolf-Peter; Lang, Stefan; Oberlinner, Christoph

    2013-01-01

    To examine perceived stress across employees with different occupational status, to investigate the impact of stress on work ability and to derive conclusions regarding health promotion activities. A comprehensive survey combining questionnaire and medical examination was offered in one division in BASF Ludwigshafen. Among 867 voluntary participants, 653 returned complete questionnaires. The questions were directed at perception of safety at the workplace, self-rated health status, frequency of stress symptoms, unrealistic job demands, time pressure and maladjustment of work life balance. The outcome of interest was self-estimated health measured by the Work Ability Index (WAI). Occupational stressors were perceived differently across occupational status groups. Frontline operators had more health concerns due to workplace conditions, while professional and managerial staff reported higher frequencies of perceived tension, time pressure, and maladjustment of work life balance. After adjustment for occupational status, demographic and lifestyle factors, perceived stress was associated with a modest to strong decline in WAI scores. While perceived occupational stress had an apparent impact on WAI, and WAI has been demonstrated to be predictive of early retirement, more intensive and employee group-specific stress management interventions are being implemented beyond traditional strategies of routine occupational medical surveillance.

  8. Second-harmonic generation at angular incidence in a negative-positive index photonic band-gap structure.

    PubMed

    D'Aguanno, Giuseppe; Mattiucci, Nadia; Scalora, Michael; Bloemer, Mark J

    2006-08-01

    In the spectral region where the refractive index of the negative index material is approximately zero, at oblique incidence, the linear transmission of a finite structure composed of alternating layers of negative and positive index materials manifests the formation of a new type of band gap with exceptionally narrow band-edge resonances. In particular, for TM-polarized (transverse magnetic) incident waves, field values that can be achieved at the band edge may be much higher compared to field values achievable in standard photonic band-gap structures. We exploit the unique properties of these band-edge resonances for applications to nonlinear frequency conversion, second-harmonic generation, in particular. The simultaneous availability of high field localization and phase matching conditions may be exploited to achieve second-harmonic conversion efficiencies far better than those achievable in conventional photonic band-gap structures. Moreover, we study the role played by absorption within the negative index material, and find that the process remains efficient even for relatively high values of the absorption coefficient.

  9. Factors related to work ability among Thai workers.

    PubMed

    Kaewboonchoo, Orawan; Saleekul, Sumlee; Usathaporn, Suthee

    2011-01-01

    This study aimed to examine the factors related to work ability among small and medium enterprise (SME) workers in Thailand. The subjects consisted of 845 males and 1,163 females. They were interviewed regarding personal information, working conditions, health status, job stress and work ability. Their blood pressure, body weight and height were also measured. More than half the subjects reported high job stress. Women had higher job stress than men. The work ability index (WAI) results for managers, supervisors and operators were 42.3, 41.4 and 39.8, respectively. Job control of managers and supervisors was higher than operators. The WAI of females decreased with increasing age for those over age 45 years. Factors related to WAI were mental health, social support at work, depression and age. The results suggest job stress reduction programs should be considered to improve work ability among SME workers.

  10. Structural and incremental validity of the Wechsler Adult Intelligence Scale-Fourth Edition with a clinical sample.

    PubMed

    Nelson, Jason M; Canivez, Gary L; Watkins, Marley W

    2013-06-01

    Structural and incremental validity of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008a) was examined with a sample of 300 individuals referred for evaluation at a university-based clinic. Confirmatory factor analysis indicated that the WAIS-IV structure was best represented by 4 first-order factors as well as a general intelligence factor in a direct hierarchical model. The general intelligence factor accounted for the most common and total variance among the subtests. Incremental validity analyses indicated that the Full Scale IQ (FSIQ) generally accounted for medium to large portions of academic achievement variance. For all measures of academic achievement, the first-order factors combined accounted for significant achievement variance beyond that accounted for by the FSIQ, but individual factor index scores contributed trivial amounts of achievement variance. Implications for interpreting WAIS-IV results are discussed. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  11. Clinical validation of the General Ability Index--Estimate (GAI-E): estimating premorbid GAI.

    PubMed

    Schoenberg, Mike R; Lange, Rael T; Iverson, Grant L; Chelune, Gordon J; Scott, James G; Adams, Russell L

    2006-09-01

    The clinical utility of the General Ability Index--Estimate (GAI-E; Lange, Schoenberg, Chelune, Scott, & Adams, 2005) for estimating premorbid GAI scores was investigated using the WAIS-III standardization clinical trials sample (The Psychological Corporation, 1997). The GAI-E algorithms combine Vocabulary, Information, Matrix Reasoning, and Picture Completion subtest raw scores with demographic variables to predict GAI. Ten GAI-E algorithms were developed combining demographic variables with single subtest scaled scores and with two subtests. Estimated GAI are presented for participants diagnosed with dementia (n = 50), traumatic brain injury (n = 20), Huntington's disease (n = 15), Korsakoff's disease (n = 12), chronic alcohol abuse (n = 32), temporal lobectomy (n = 17), and schizophrenia (n = 44). In addition, a small sample of participants without dementia and diagnosed with depression (n = 32) was used as a clinical comparison group. The GAI-E algorithms provided estimates of GAI that closely approximated scores expected for a healthy adult population. The greatest differences between estimated GAI and obtained GAI were observed for the single subtest GAI-E algorithms using the Vocabulary, Information, and Matrix Reasoning subtests. Based on these data, recommendations for the use of the GAI-E algorithms are presented.

  12. Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review.

    PubMed

    Skelin, Marko; Lucijanić, Tomo; Amidžić Klarić, Daniela; Rešić, Arnes; Bakula, Miro; Liberati-Čizmek, Ana-Marija; Gharib, Hossein; Rahelić, Dario

    2017-02-01

    Levothyroxine (LT4) is a drug with a narrow therapeutic index, applied in small amounts (micrograms), which makes interactions in the absorption phase clinically significant. The main aim of this article was to review and present the latest information on factors that affect the gastrointestinal absorption of this drug. Relevant data were collected by using the MEDLINE, PubMed, EMBASE, Web of Science, Science Direct, and Scopus databases with the key words levothyroxine and absorption. Searches were not limited to specific publication types, study designs, dates, or languages. The reports were highly variable in the amount of information provided regarding study design and methods. Because of the heterogeneity of studies, no statistical analysis was performed. Many gastrointestinal disorders, such as celiac disease, atrophic gastritis, lactose intolerance, and Helicobacter pylori infection, may impede the absorption of levothyroxine. During treatment of these disorders, it is necessary to monitor serum thyroid-stimulating hormone and free T4 values to reduce the risk of developing iatrogenic hyperthyroidism. Soybeans and coffee have the greatest impact on the reduction of absorption, whereas vitamin C has the ability to increase it. Conversely, the effect of dietary fiber on the absorption of LT4 is not yet fully understood; further research is needed on this topic. A decrease in the absorption of LT4 is established and clinically significant when administered concomitantly with cholestyramine, colesevelam, lanthanum, calcium carbonate, calcium citrate, calcium acetate, iron sulfate, ciprofloxacin, aluminum hydroxide, sevelamer, or proton pump inhibitors. This effect should be taken into consideration when prescribing these drugs concomitantly with LT4. The effects of Giardia lamblia infection and the influence of orlistat, polystyrene sulfonate, raloxifene, and simethicone on absorption of LT4 have been poorly documented. For bariatric surgery, sucralfate and H 2

  13. Aerosol Absorption Effects in the TOMS UV Algorithm

    NASA Technical Reports Server (NTRS)

    Torres, O.; Krotkov, N.; Bhartia, P. K.

    2004-01-01

    The availability of global long-term estimates of surface UV radiation is very important, not only for preventive medicine considerations, but also as an important tool to monitor the effects of the stratospheric ozone recovery expected to occur in the next few decades as a result of the decline of the stratospheric chlorine levels. In addition to the modulating effects of ozone and clouds, aerosols also affect the levels of UV-A and W-B radiation reaching the surface. Oscillations in surface W associated with the effects of aerosol absorption may be comparable in magnitude to variations associated with the stratospheric ozone recovery. Thus, the accurate calculation of surface W radiation requires that both the scattering and absorption effects of tropospheric aerosols be taken into account. Although absorption effects of dust and elevated carbonaceous aerosols are already accounted for using Aerosol Index technique, this approach does not work for urban/industrial aerosols in the planetary boundary layer. The use of the new TOMS long-term global data record on UV aerosol absorption optical depth, can improve the accuracy of TOMS spectral UV products, by properly including the spectral attenuation effects of carbonaceous, urban/industrial and mineral aerosols. The TOMS data set on aerosol properties will be discussed, and results of its use in the TOMS surface W algorithm will be presented.

  14. The “Wireless Sensor Networks for City-Wide Ambient Intelligence (WISE-WAI)” Project

    PubMed Central

    Casari, Paolo; Castellani, Angelo P.; Cenedese, Angelo; Lora, Claudio; Rossi, Michele; Schenato, Luca; Zorzi, Michele

    2009-01-01

    This paper gives a detailed technical overview of some of the activities carried out in the context of the “Wireless Sensor networks for city-Wide Ambient Intelligence (WISE-WAI)” project, funded by the Cassa di Risparmio di Padova e Rovigo Foundation, Italy. The main aim of the project is to demonstrate the feasibility of large-scale wireless sensor network deployments, whereby tiny objects integrating one or more environmental sensors (humidity, temperature, light intensity), a microcontroller and a wireless transceiver are deployed over a large area, which in this case involves the buildings of the Department of Information Engineering at the University of Padova. We will describe how the network is organized to provide full-scale automated functions, and which services and applications it is configured to provide. These applications include long-term environmental monitoring, alarm event detection and propagation, single-sensor interrogation, localization and tracking of objects, assisted navigation, as well as fast data dissemination services to be used, e.g., to rapidly re-program all sensors over-the-air. The organization of such a large testbed requires notable efforts in terms of communication protocols and strategies, whose design must pursue scalability, energy efficiency (while sensors are connected through USB cables for logging and debugging purposes, most of them will be battery-operated), as well as the capability to support applications with diverse requirements. These efforts, the description of a subset of the results obtained so far, and of the final objectives to be met are the scope of the present paper. PMID:22408513

  15. THE VIEWING ANGLES OF BROAD ABSORPTION LINE VERSUS UNABSORBED QUASARS

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

    DiPompeo, M. A.; Brotherton, M. S.; De Breuck, C.

    2012-06-10

    It was recently shown that there is a significant difference in the radio spectral index distributions of broad absorption line (BAL) quasars and unabsorbed quasars, with an overabundance of BAL quasars with steeper radio spectra. This result suggests that source orientation does play into the presence or absence of BAL features. In this paper, we provide more quantitative analysis of this result based on Monte Carlo simulations. While the relationship between viewing angle and spectral index does indeed contain a lot of scatter, the spectral index distributions are different enough to overcome that intrinsic variation. Utilizing two different models ofmore » the relationship between spectral index and viewing angle, the simulations indicate that the difference in spectral index distributions can be explained by allowing BAL quasar viewing angles to extend about 10 Degree-Sign farther from the radio jet axis than non-BAL sources, though both can be seen at small angles. These results show that orientation cannot be the only factor determining whether BAL features are present, but it does play a role.« less

  16. Refractive index sensing with Fano resonances in silicon oligomers

    PubMed Central

    Chong, Katie E.; Orton, Henry W.; Decker, Manuel; Miroshnichenko, Andrey E.; Brener, Igal; Kivshar, Yuri S.

    2017-01-01

    We demonstrate experimentally refractive index sensing with localized Fano resonances in silicon oligomers, consisting of six disks surrounding a central one of slightly different diameter. Owing to the low absorption and narrow Fano-resonant spectral features appearing as a result of the interference of the modes of the outer and the central disks, we demonstrate refractive index sensitivity of more than 150 nm RIU−1 with a figure of merit of 3.8. This article is part of the themed issue ‘New horizons for nanophotonics’. PMID:28220001

  17. MULTIMAGNON ABSORPTION IN MNF2-OPTICAL ABSORPTION SPECTRUM.

    DTIC Science & Technology

    The absorption spectrum of MnF2 at 4.2K in the 3900A region was measured in zero external fields and in high fields. Exciton lines with magnon ...sidebands are observed, accompanied by a large number of weak satellite lines. Results on the exciton and magnon absorptions are similar to those of...McClure et al. The satellite lines are interpreted as being multi- magnon absorptions, and it is possible to fit the energy of all the absorptions with

  18. Absorption atelectasis: incidence and clinical implications.

    PubMed

    O'Brien, Jennifer

    2013-06-01

    General anesthesia is known to cause pulmonary atelectasis; in turn, atelectasis increases shunt, decreases compliance, and may lead to perioperative hypoxemia. One mechanism for the formation of atelectasis intraoperatively is ventilation with 100% oxygen. The goal of this review is to determine if research suggests that intraoperative ventilation with 100% oxygen leads to clinically significant pulmonary side effects. An initial literature search included electronic databases (Cumulative Index to Nursing & Allied Health Literature [CINAHL], PubMed, MEDLINE, Embase, and The GeneraCochrane Library) using the following search terms: oxygen (administration and dosage), atelectasis, pulmonary complications, and anesthesia. Results were limited to research studies, human subjects, and English-language publications between 1965 and 2011. From this body of research, it appears that absorption atelectasis does occur in healthy anesthetized adults breathing 100% oxygen. Data reviewed suggest that absorption atelectasis does not have significant clinical implications in healthy adults. However, further research is warranted in populations at increased risk of postoperative hypoxemia, including obese or elderly patients and those with preexisting cardiopulmonary disease.

  19. Optimization of the acoustic absorption coefficients of certain functional absorbents

    NASA Technical Reports Server (NTRS)

    Pocsa, V.; Biborosch, L.; Veres, A.; Halpert, E.; Lorian, R.; Botos, T.

    1974-01-01

    The sound absorption coefficients of some functional absorbents (mineral wool plates) are determined by the reverberation chamber method. The influence of the angle of inclination of the sound absorbing material with respect to the surface to be treated is analyzed as well as the influence of the covering index, defined as the ratio of the designed area of a plate and the area of the treated surface belonging to another plate. As compared with the conventional method of applying sound-absorbing plates, the analyzed structures have a higher technological and economical efficiency. The optimum structure corresponds to an angle of inclination of 15 deg and a covering index of 0.8.

  20. [Relationship between occupational stress and working ability of workers in a petroleum processing enterprise in high altitude area].

    PubMed

    Ma, X M; Kang, H L; Shi, C B; Li, Y; Wu, Y F; Liu, Z H; Wang, G; Lei, H Y

    2017-12-20

    Objective: To investigate the relationship between occupational stress and working ability of workers in a petroleum processing enterprise in a high altitude area. Methods: A total of 728 workers in a petroleum processing enterprise at an altitude of 2850 m were subjected to a survey using Occupational Stress Inventory (OSI) , Work Ability Index (WAI) Scale, Occupational Role Questionnaire (ORQ) , Personal Strain Questionnaire (PSQ) , and Personal Resource Questionnaire (PRQ) from May 2014 to August 2016. Results: Of the 728 workers, 55 (7.6%) had a poor working ability, moderate in 262 (35.9%) , and good in 411 (56.5%). There were significant differences in WAI between the workers with different types of work, sexes, ages, and working years ( P <0.05). There was a significant difference in WAI between different occupational stress groups ( P <0.05). WAI was negatively correlated with ORQ score and PSQ score ( r (s)=-0.387, P <0.05; r (s)=-0.467, P <0.05) and positively correlated with PRQ score ( r (s)=0.343, P <0.05). The multiple linear regression analysis showed that high ORQ score and PSQ score were the inhibitory factors for high WAI ( B =-0.058; B =-0.082) and high PRQ score was a contributing factor for high WAI ( B =0.029) . Conclusion: Occupational stress is an influencing factor for the working ability of workers in the petroleum processing enterprise in the high altitude area. Hypoxia in high altitude area may further reduce the working ability. In order to reduce occupational stress and improve work ability, it should be considered to strengthen skills training, improve the working environment, and pay attention to mental health.

  1. Enhancing intensity and refractive index sensing capability with infrared plasmonic perfect absorbers.

    PubMed

    Cheng, Fei; Yang, Xiaodong; Gao, Jie

    2014-06-01

    An infrared refractive index sensor based on plasmonic perfect absorbers for glucose concentration sensing is experimentally demonstrated. Utilizing substantial absorption contrast between a perfect absorber (∼98% at normal incidence) and a non-perfect absorber upon the refractive index change, a maximum value of figure of merit (FOM*) about 55 and a bulk wavelength sensitivity about 590  nm/RIU are achieved. The demonstrated sensing platform provides great potential in improving the performance of plasmonic refractive index sensors and developing future surface enhanced infrared spectroscopy.

  2. Intergalactic Helium Absorption toward High-Redshift Quasars

    NASA Technical Reports Server (NTRS)

    Giroux, Mark L.; Fardal, Mark A.; Shull, J. Michael

    1995-01-01

    The recent Hubble Space Telescope (HST) observations of the z(q) = 3.286 quasar Q0302-003 (Jakobsen et at. 1994) and the z(q) = 3.185 quasar Q1935-67 by Tytler (1995) show absorption edges at the redshifted wavelength of He II 304 A. A key goal is to distinguish between contributions from discrete Ly-alpha forest clouds and a smoothly distributed intergalactic medium (IGM). We model the contributions from each of these sources of He II absorption, including the distribution of line Doppler widths and column densities, the 'He II proximity effect' from the quasar, and a self-consistent derivation of the He II opacity of the universe as a function of the spectrum of ionizing sources, with the assumption that both the clouds and the IGM are photoionized. The He II edge can be fully accounted for by He II line blanketing for reasonable distributions of line widths and column densities in the Ly-alpha forest, provided that the ionizing sources have spectral index alpha(s) greater than 1.5, and any He II proximity effect is neglected. Even with some contribution from a diffuse IGM, it is difficult to account for the edge observed by Jakobsen et al. (1994) with a 'hard' source spectrum (alpha(s) less than 1.3). The proximity effect modifies the relative contributions of the clouds and IGM to tau(He II) near the quasar (z approx. less than z(q)) and markedly increases the amount of He II absorption required. This implies, for example, that to account for the He II edge with line blanketing alone, the minimum spectral index alpha(s) must be increased from 1.5 to 1.9. We demonstrate the need for higher resolution observations that characterize the change in transmission as z approaches z(q) and resolve line-free gaps in the continuum. We set limits on the density of the diffuse IGM and suggest that the IGM and Ly-alpha clouds are likely to be a significant repository for dark baryons.

  3. Applying workability in the Australian residential aged care context.

    PubMed

    Brooke, Elizabeth; Goodall, Joanne; Handrus, Maxwell; Mawren, Daveena

    2013-06-01

    The study is based on an innovative demonstration project which trialled the implementation of the Finnish 'workability' framework and research measures. It aimed, firstly, to test the applicability of the Workability Index (WAI) to the Australian residential aged care workforce, focusing on personal care assistants (PCAs), and secondly, to assess the effectiveness of actions aimed at improving workability. The facility manager implemented multidimensional 'actions' according to the workability framework. The Workability Survey (WAS) and WAI and intervention instruments were administered (n = 64). Completed responses to 'pre' and 'post' instruments formed matched pairs (n = 15). WAI scores increased significantly, by 3 points on average, after all 'actions' were implemented. The only significant 'action' was increasing the number of PCAs in high care. Workability provides a useful research workforce development instrument measuring interactions between aged care workers and organisational demands and the outcomes of 'actions'. © 2013 The Authors. Australasian Journal on Ageing © 2013 ACOTA.

  4. The relationship between work ability and oxidative stress in Japanese workers.

    PubMed

    Ohta, Masanori; Kumashiro, Masaharu; Eguchi, Yasumasa; Morita, Yusaku; Konno, Yoshimasa; Yamato, Hiroshi

    2014-01-01

    Work ability is based on the balance between personal resources and work demand. This study focused on the personal resources component of work ability. The aims of this study were to elucidate the association between work ability and cardiovascular (CV) risk factors, particularly oxidative stress, and to estimate the effect of a community-implemented lifestyle modification programme on work ability and CV risk factors. Urinary 8-iso-prostaglandin F2α (PGF2α), a biomarker of oxidative stress, was negatively correlated with psychological resources, as measured by the Work Ability Index (WAI). Overall WAI score was unchanged following the programme, while CV risk factors and antioxidative activity improved. A reduction in PGF2α levels was correlated with an improvement in subjective work ability relative to job demands, as assessed by a WAI item. Taken together, the results suggest that lifestyle modification programmes enhance the personal resources component of work ability and are associated with a reduction in oxidative stress.

  5. Wide-aperture total absorption of a terahertz wave in a nanoperiodic graphene-based plasmon structure

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

    Polischuk, O. V., E-mail: polischuk.sfire@mail.ru; Melnikova, V. S.; Popov, V. V., E-mail: popov-slava@yahoo.co.uk

    2016-11-15

    The terahertz absorption spectrum in a periodic array of graphene nanoribbons located on the surface of a dielectric substrate with a high refractive index (terahertz prism) is studied theoretically. The total absorption of terahertz radiation is shown to occur in the regime of total internal reflection of the terahertz wave from the periodic array of graphene nanoribbons, at the frequencies of plasma oscillations in graphene, in a wide range of incidence angles of the external terahertz wave even at room temperature.

  6. Critical Dispersion-Theory Tests of Silicon's IR Refractive Index

    NASA Astrophysics Data System (ADS)

    Karstens, William; Smith, D. Y.

    Silicon strongly absorbs both visible and UV light, but is highly transparent in the IR. Hence, it is a common choice for infrared windows and lenses. However, optical design is hindered by literature index values that disagree by up to 1%. In contrast optical-glass indices are known to 0.01% or better. The most widely available silicon IR indices are based on bulk measurements using either Snell's-Law refraction by a prism or channel-spectra interference of front- and backsurface reflections from a planar sample. To test the physical acceptability of these data, we have developed criteria based on a Taylor expansion of the Kramers-Kronig relation for the index at energies below strong inter-band transitions. These tests require that the coefficients of the series in powers of energy squared must be positive within the region of transparency. This is satisfied by essentially all prism measurements; their small scatter arises primarily from impurities and doping. In contrast, channel-spectra data fail in the second and third coefficients. A review of the experimental analysis indicates three problems besides purity: incorrect channel number arising from a channel-spectra model that neglects spectrum distortion by the weak lattice absorption; use of a series expansion of mixed parity in photon energy to describe the even-parity index; and use of an incorrect absorption energy in the Li-Sellmeier dispersion formula. Recommendations for IR index values for pure silicon will be discussed. Supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC02-06CH11357.

  7. Optical constants of ammonium sulfate in the infrared. [stratospheric aerosol refractive and absorption indices

    NASA Technical Reports Server (NTRS)

    Downing, H. D.; Pinkley, L. W.; Sethna, P. P.; Williams, D.

    1977-01-01

    The infrared spectral reflectance at near normal incidence has been measured for 3.2 M, 2.4 M, and 1.6 M solutions of ammonium sulfate, an aerosol abundant in the stratosphere and also present in the troposphere. Kramers-Kronig analysis was used to determine values of the refractive and absorption indices from the measured spectral reflectance. A synthetic spectrum of crystalline ammonium sulfate was obtained by extrapolation of the absorption index obtained for the solution to the absorber number densities of the NH4 and SO4 ions characteristic of the crystal.

  8. [Everted intestinal sac method for quick finding absorption ingredients of Wuzhuyu decoction].

    PubMed

    Gong, Muxin; Wang, Yaxun; Song, Yafang; Wang, Zhimin; Zhang, Qiwei; Wang, Weihao; Zhu, Jingjing

    2010-06-01

    To establish a method for quick finding the absorption ingredients of Wuzhuyu decoction in order to select the index to control its quality. The absorption of three concentration of Wuzhuyu decotion was investigated with the in vitro-everted intestinal sac model. The intestinal bag fluid of jejunum and ileum were collected in different time and the eight ingredients, which were evodiamine (Ev), rutaecarpine (Ru), limonin (Li), ginsenoside-Rb1, -Rg1, -Re (Rb1, Rg1, Re), isorhamnetin-3-O-beta-D-glucosyl(6''-->1'")-alpha-L-rhamnoside (Irs)and 6-gingerol (6-Gi), were detected by HPLC as the represent constituents in samples. Eight ingredients except Ru in samples could be detected, but Ev could not be detected in high concentration samples. The ratios between absorption ingredients were different from in Wuzhuyu decotion. The in vitro-everted intestinal sac canc absorb the ingredients of Wuzhuyu decotion selectivity. Compare with the ileum, the jejunum can provide the more absorption information and faster, the best test time is 60-90 min.

  9. Abnormal dispersion of refractive index of purple membranes in an aqueous medium.

    PubMed

    Zhivkov, Alexandar Metodiev

    2010-01-10

    The refractive index of purple membranes in a water suspension has been measured refractometrically in the visible range of the spectrum. A region of anomalous dispersion has been found, due to a strong absorption by the retinal residue in bacteriorhodopsin macromolecules.

  10. Precise Measurement of Refractive Index and Absorption Coefficient of Near Millimeter Wave and Far Infrared Materials.

    DTIC Science & Technology

    1987-06-01

    polyethylene. The plexiglass is a polymethyl methacrylate and the acrylic is a polymethacrylate . The polyamide(nylon) is made with adipic acid and hexamethylene...are made with acrylic acid . It was not sur- prizing to see both exhibiting similar absorption characteristics atleast 30 times higher than

  11. Indirect absorption spectroscopy using quantum cascade lasers: mid-infrared refractometry and photothermal spectroscopy.

    PubMed

    Pfeifer, Marcel; Ruf, Alexander; Fischer, Peer

    2013-11-04

    We record vibrational spectra with two indirect schemes that depend on the real part of the index of refraction: mid-infrared refractometry and photothermal spectroscopy. In the former, a quantum cascade laser (QCL) spot is imaged to determine the angles of total internal reflection, which yields the absorption line via a beam profile analysis. In the photothermal measurements, a tunable QCL excites vibrational resonances of a molecular monolayer, which heats the surrounding medium and changes its refractive index. This is observed with a probe laser in the visible. Sub-monolayer sensitivities are demonstrated.

  12. Physical exercise at the workplace prevents deterioration of work ability among healthcare workers: cluster randomized controlled trial.

    PubMed

    Jakobsen, Markus D; Sundstrup, Emil; Brandt, Mikkel; Jay, Kenneth; Aagaard, Per; Andersen, Lars L

    2015-11-25

    Imbalance between individual resources and work demands can lead to musculoskeletal disorders and reduced work ability. The purpose of this study was to investigate the effect of workplace- versus home-based physical exercise on work ability among healthcare workers. Two hundred female healthcare workers (Age: 42.0, BMI: 24.1, work ability index [WAI]: 43.1) from 18 departments at three Danish hospitals participated (Copenhagen, Denmark, Aug 2013-Jan 2014). Participants were randomly allocated at the cluster level to 10 weeks of: 1) workplace physical exercise (WORK) performed during working hours for 5x10 min per week and up to 5 group-based coaching sessions on motivation for regular physical exercise, or 2) home-based physical exercise (HOME) performed during leisure time for 5x10 min per week. Both groups received ergonomic counseling on patient handling and use of lifting aides. The main outcome measure was the change from baseline to 10-week follow-up in WAI. Significant group by time interaction was observed for WAI (p < 0.05). WAI at follow-up was 1.1 (0.3 to 1.8) higher in WORK compared with HOME corresponding to a small effect size (Cohens'd = 0.24). Within-group changes indicated that between-group differences were mainly caused by a reduction in WAI in HOME. Of the seven items of WAI, item 2 (work ability in relation to the demands of the job) and item 5 (sickness absence during the past year) were improved in WORK compared with HOME (P < 0.05). Performing physical exercise together with colleagues at the workplace prevents deterioration of work ability among female healthcare workers. ClinicalTrials.gov NCT01921764 . Registered 10 August 2013.

  13. Remote sensing of soot carbon - Part 2: Understanding the absorption Ångström exponent

    NASA Astrophysics Data System (ADS)

    Schuster, G. L.; Dubovik, O.; Arola, A.; Eck, T. F.; Holben, B. N.

    2016-02-01

    Recently, some authors have suggested that the absorption Ångström exponent (AAE) can be used to deduce the component aerosol absorption optical depths (AAODs) of carbonaceous aerosols in the AERONET database. This AAE approach presumes that AAE ≪ 1 for soot carbon, which contrasts the traditional small particle limit of AAE = 1 for soot carbon. Thus, we provide an overview of the AERONET retrieval, and we investigate how the microphysics of carbonaceous aerosols can be interpreted in the AERONET AAE product. We find that AAE ≪ 1 in the AERONET database requires large coarse mode fractions and/or imaginary refractive indices that increase with wavelength. Neither of these characteristics are consistent with the current definition of soot carbon, so we explore other possibilities for the cause of AAE ≪ 1. AAE is related to particle size, and coarse mode particles have a smaller AAE than fine mode particles for a given aerosol mixture of species. We also note that the mineral goethite has an imaginary refractive index that increases with wavelength, is very common in dust regions, and can easily contribute to AAE ≪ 1. We find that AAE ≪ 1 can not be caused by soot carbon, unless soot carbon has an imaginary refractive index that increases with wavelength throughout the visible and near-infrared spectrums. Finally, AAE is not a robust parameter for separating carbonaceous absorption from dust aerosol absorption in the AERONET database.

  14. Direct index of refraction measurements at extreme-ultraviolet and soft-x-ray wavelengths.

    PubMed

    Rosfjord, Kristine; Chang, Chang; Miyakawa, Ryan; Barth, Holly; Attwood, David

    2006-03-10

    Coherent radiation from undulator beamlines has been used to directly measure the real and imaginary parts of the index of refraction of several materials at both extreme-ultraviolet and soft-x-ray wavelengths. Using the XOR interferometer, we measure the refractive indices of silicon and ruthenium, essential materials for extreme-ultraviolet lithography. Both materials are tested at wavelength (13.4 nm) and across silicon's L2 (99.8 eV) and L3 (99.2 eV) absorption edges. We further extend this direct phase measurement method into the soft-x-ray region, where measurements of chromium and vanadium are performed around their L3 absorption edges at 574.1 and 512.1 eV, respectively. These are the first direct measurements, to our knowledge, of the real part of the index of refraction made in the soft-x-ray region.

  15. Insulin Resistance in Nondiabetic Peritoneal Dialysis Patients: Associations with Body Composition, Peritoneal Transport, and Peritoneal Glucose Absorption.

    PubMed

    Bernardo, Ana Paula; Oliveira, Jose C; Santos, Olivia; Carvalho, Maria J; Cabrita, Antonio; Rodrigues, Anabela

    2015-12-07

    Insulin resistance has been associated with cardiovascular disease in peritoneal dialysis patients. Few studies have addressed the impact of fast transport status or dialysis prescription on insulin resistance. The aim of this study was to test whether insulin resistance is associated with obesity parameters, peritoneal transport rate, and glucose absorption. Insulin resistance was evaluated with homeostasis model assessment method (HOMA-IR), additionally corrected by adiponectin (HOMA-AD). Enrolled patients were prevalent nondiabetics attending at Santo António Hospital Peritoneal Dialysis Unit, who were free of hospitalization or infectious events in the previous 3 months (51 patients aged 50.4 ± 15.9 years, 59% women). Leptin, adiponectin, insulin-like growth factor-binding protein 1 (IGFBP-1), and daily glucose absorption were also measured. Lean tissue index, fat tissue index (FTI), and relative fat mass (rel.FM) were assessed using multifrequency bioimpedance. Patients were categorized according to dialysate to plasma creatinine ratio at 4 hours, 3.86% peritoneal equilibration test, and obesity parameters. Obesity was present in 49% of patients according to rel.FM. HOMA-IR correlated better with FTI than with body mass index. Significant correlations were found in obese, but not in nonobese patients, between HOMA-IR and leptin, leptin/adiponectin ratio (LAR), and IGFBP-1. HOMA-IR correlated with HOMA-AD, but did not correlate with glucose absorption or transport rate. There were no significant differences in insulin resistance indices, glucose absorption, and body composition parameters between fast and nonfast transporters. A total of 18 patients (35.3%) who had insulin resistance presented with higher LAR and rel.FM (7.3 [12.3, interquartile range] versus 0.7 [1.4, interquartile range], P<0.001, and 39.4 ± 10.1% versus 27.2 ± 11.5%, P=0.002, respectively), lower IGFBP-1 (8.2 ± 7.2 versus 21.0 ± 16.3 ng/ml, P=0.002), but similar glucose absorption and

  16. Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond z-scan measurements

    NASA Astrophysics Data System (ADS)

    Kamaraju, N.; Kumar, Sunil; Sood, A. K.; Guha, Shekhar; Krishnamurthy, Srinivasan; Rao, C. N. R.

    2007-12-01

    Nonlinear transmission of 80 and 140fs pulsed light with 0.79μm wavelength through single walled carbon nanotubes suspended in water containing sodium dodecyl sulfate is studied. Pulse-width independent saturation absorption and negative cubic nonlinearity are observed, respectively, in open and closed aperture z-scan experiments. The theoretical expressions derived to analyze the z-dependent transmission in the saturable limit require two photon absorption coefficient β0˜1.4cm/MW and a nonlinear index γ ˜-5.5×10-11cm2/W to fit the data.

  17. [Dust absorption capacities of eight evergreen broad-leaved plants in Beijing, China.

    PubMed

    Fan, Shu Xin; Cai, Yu; Dong, Li

    2017-02-01

    Aiming at selecting the evergreen broad-leaved plants with excellent dust capturing capacity that can be applied in Beijing area for improving the urban vegetation dust removal, this study selected 8 evergreen (including semi-evergreen) broad-leaved plants used in urban green-space in Beijing area to measure the dust absorption per unit leaf area by the elution-mass method during winter and early spring in 2014. The dust deposition per leaf and per plant of each species was further calculated for tested species. Based on the dust capturing capacity measured in different units, cluster analysis on the comprehensive dust absorption capacities of different plants was carried out from the corresponding aspect. Results showed that the dust absorption ability differed significantly among the 8 evergreen broad-leaved (including semi-evergreen) species including Buxus sinica, Euonymus japonicus, Ligustrum quihoui, L. vicaryi, E. kiautschovicus, Indocalamus tessellatus, Phyllostachys violascens and Ph. aureosulcata. E. japonicus was best in dust absorption per unit leaf area and per plant, with 1.36 g·m -2 and 59.63 g·plant -1 . I. tessellates (with 1.62 mg·leaf -1 ) had the strongest dust absorption ability per leaf. With different measurement units selected, the ranking changed. The cluster analysis based on the multi index comprehensive dust absorption capacities could roughly divided the 8 evergreen broad-leaved species into 4 categories representing different dust absorption capacity levels. E. japonicus and Ph. sviolascens had the outstanding comprehensive dust capturing capacity, while B. sinica, L. vicaryi and Ph. aureosulcata showed the weak performance.

  18. The WAIS Melt Monitor: An automated ice core melting system for meltwater sample handling and the collection of high resolution microparticle size distribution data

    NASA Astrophysics Data System (ADS)

    Breton, D. J.; Koffman, B. G.; Kreutz, K. J.; Hamilton, G. S.

    2010-12-01

    Paleoclimate data are often extracted from ice cores by careful geochemical analysis of meltwater samples. The analysis of the microparticles found in ice cores can also yield unique clues about atmospheric dust loading and transport, dust provenance and past environmental conditions. Determination of microparticle concentration, size distribution and chemical makeup as a function of depth is especially difficult because the particle size measurement either consumes or contaminates the meltwater, preventing further geochemical analysis. Here we describe a microcontroller-based ice core melting system which allows the collection of separate microparticle and chemistry samples from the same depth intervals in the ice core, while logging and accurately depth-tagging real-time electrical conductivity and particle size distribution data. This system was designed specifically to support microparticle analysis of the WAIS Divide WDC06A deep ice core, but many of the subsystems are applicable to more general ice core melting operations. Major system components include: a rotary encoder to measure ice core melt displacement with 0.1 millimeter accuracy, a meltwater tracking system to assign core depths to conductivity, particle and sample vial data, an optical debubbler level control system to protect the Abakus laser particle counter from damage due to air bubbles, a Rabbit 3700 microcontroller which communicates with a host PC, collects encoder and optical sensor data and autonomously operates Gilson peristaltic pumps and fraction collectors to provide automatic sample handling, melt monitor control software operating on a standard PC allowing the user to control and view the status of the system, data logging software operating on the same PC to collect data from the melting, electrical conductivity and microparticle measurement systems. Because microparticle samples can easily be contaminated, we use optical air bubble sensors and high resolution ice core density

  19. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  20. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, R.C.; Biermann, W.J.

    1989-05-09

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

  1. Integrated three-dimensional photonic nanostructures for achieving near-unity solar absorption and superhydrophobicity

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

    Kuang, Ping; Lin, Shawn-Yu, E-mail: sylin@rpi.edu; Hsieh, Mei-Li

    2015-06-07

    In this paper, we proposed and realized 3D photonic nanostructures consisting of ultra-thin graded index antireflective coatings (ARCs) and woodpile photonic crystals. The use of the integrated ARC and photonic crystal structure can achieve broadband, broad-angle near unity solar absorption. The amorphous silicon based photonic nanostructure experimentally shows an average absorption of ∼95% for λ = 400–620 nm over a wide angular acceptance of θ = 0°–60°. Theoretical studies show that a Gallium Arsenide (GaAs) based structure can achieve an average absorption of >95% for λ = 400–870 nm. Furthermore, the use of the slanted SiO{sub 2} nanorod ARC surface layer by glancing angle deposition exhibits Cassie-Baxter statemore » wetting, and superhydrophobic surface is obtained with highest water contact angle θ{sub CB} ∼ 153°. These properties are fundamentally important for achieving maximum solar absorption and surface self-cleaning in thin film solar cell applications.« less

  2. Resonant Absorption in GaAs-Based Nanowires by Means of Photo-Acoustic Spectroscopy

    NASA Astrophysics Data System (ADS)

    Petronijevic, E.; Leahu, G.; Belardini, A.; Centini, M.; Li Voti, R.; Hakkarainen, T.; Koivusalo, E.; Guina, M.; Sibilia, C.

    2018-03-01

    Semiconductor nanowires made of high refractive index materials can couple the incoming light to specific waveguide modes that offer resonant absorption enhancement under the bandgap wavelength, essential for light harvesting, lasing and detection applications. Moreover, the non-trivial ellipticity of such modes can offer near field interactions with chiral molecules, governed by near chiral field. These modes are therefore very important to detect. Here, we present the photo-acoustic spectroscopy as a low-cost, reliable, sensitive and scattering-free tool to measure the spectral position and absorption efficiency of these modes. The investigated samples are hexagonal nanowires with GaAs core; the fabrication by means of lithography-free molecular beam epitaxy provides controllable and uniform dimensions that allow for the excitation of the fundamental resonant mode around 800 nm. We show that the modulation frequency increase leads to the discrimination of the resonant mode absorption from the overall absorption of the substrate. As the experimental data are in great agreement with numerical simulations, the design can be optimized and followed by photo-acoustic characterization for a specific application.

  3. X-ray tomography using the full complex index of refraction.

    PubMed

    Nielsen, M S; Lauridsen, T; Thomsen, M; Jensen, T H; Bech, M; Christensen, L B; Olsen, E V; Hviid, M; Feidenhans'l, R; Pfeiffer, F

    2012-10-07

    We report on x-ray tomography using the full complex index of refraction recorded with a grating-based x-ray phase-contrast setup. Combining simultaneous absorption and phase-contrast information, the distribution of the full complex index of refraction is determined and depicted in a bivariate graph. A simple multivariable threshold segmentation can be applied offering higher accuracy than with a single-variable threshold segmentation as well as new possibilities for the partial volume analysis and edge detection. It is particularly beneficial for low-contrast systems. In this paper, this concept is demonstrated by experimental results.

  4. The complex refractive index of atmospheric and model humic-like substances (HULIS) retrieved by a cavity ring down aerosol spectrometer (CRD-AS).

    PubMed

    Dinar, E; Riziq, A Abo; Spindler, C; Erlick, C; Kiss, G; Rudich, Y

    2008-01-01

    Atmospheric aerosols absorb and reflect solar radiation causing surface cooling and heating of the atmosphere. The interaction between aerosols and radiation depends on their complex index of refraction, which is related to the particles' chemical composition. The contribution of light absorbing organic compounds, such as HUmic-LIke Substances (HULIS) to aerosol scattering and absorption is among the largest uncertainties in assessing the direct effect of aerosols on climate. Using a Cavity Ring Down Aerosol Spectrometer (CRD-AS), the complex index of refraction of aerosols containing HULIS extracted from pollution, smoke, and rural continental aerosols, and molecular weight-fractionated fulvic acid was measured at 390 nm and 532 nm. The imaginary part of the refractive index (absorption) substantially increases towards the UV range with increasing molecular weight and aromaticity. At both wavelengths, HULIS extracted from pollution and smoke particles absorb more than HULIS from the rural aerosol. Sensitivity calculations for a pollution-type aerosol containing ammonium sulfate, organic carbon (HULIS), and soot suggests that accounting for absorption by HULIS leads in most cases to a significant decrease in the single scattering albedo and to a significant increase in aerosol radiative forcing efficiency, towards more atmospheric absorption and heating. This indicates that HULIS in biomass smoke and pollution aerosols, in addition to black carbon, can contribute significantly to light absorption in the ultraviolet and visible spectral regions.

  5. Interpreting the Ultraviolet Aerosol Index Observed with the OMI Satellite Instrument to Understand Absorption by Organic Aerosols: Implications for Atmospheric Oxidation and Direct Radiative Effects

    NASA Technical Reports Server (NTRS)

    Hammer, Melanie S.; Martin, Randall V.; Donkelaar, Aaron van; Buchard, Virginie; Torres, Omar; Ridley, David A.; Spurr, Robert J. D.

    2016-01-01

    Satellite observations of the ultraviolet aerosol index (UVAI) are sensitive to absorption of solar radiation by aerosols; this absorption affects photolysis frequencies and radiative forcing. We develop a global simulation of the UVAI using the 3-D chemical transport model GEOSChem coupled with the Vector Linearized Discrete Ordinate Radiative Transfer model (VLIDORT). The simulation is applied to interpret UVAI observations from the Ozone Monitoring Instrument (OMI) for the year 2007. Simulated and observed values are highly consistent in regions where mineral dust dominates the UVAI, but a large negative bias (-0.32 to -0.97) exists between simulated and observed values in biomass burning regions. We determine effective optical properties for absorbing organic aerosol, known as brown carbon (BrC), and implement them into GEOS-Chem to better represent observed UVAI values over biomass burning regions. The inclusion of absorbing BrC decreases the mean bias between simulated and OMI UVAI values from -0.57 to -0.09 over West Africa in January, from -0.32 to +0.0002 over South Asia in April, from -0.97 to -0.22 over southern Africa in July, and from -0.50 to +0.33 over South America in September. The spectral dependence of absorption after including BrC in the model is broadly consistent with reported observations for biomass burning aerosol, with absorbing Angstrom exponent (AAE) values ranging from 2.9 in the ultraviolet (UV) to 1.3 across the UV-Near IR spectrum. We assess the effect of the additional UV absorption by BrC on atmospheric photochemistry by examining tropospheric hydroxyl radical (OH) concentrations in GEOS-Chem. The inclusion of BrC decreases OH by up to 30% over South America in September, up to 20% over southern Africa in July, and up to 15% over other biomass burning regions. Global annual mean OH concentrations in GEOS-Chem decrease due to the presence of absorbing BrC, increasing the methyl chloroform lifetime from 5.62 to 5.68 years, thus

  6. Reversible unidirectional reflection and absorption of PT-symmetry structure under electro-optical modulation

    NASA Astrophysics Data System (ADS)

    Fang, Yun-tuan; Zhang, Yi-chi; Xia, Jing

    2018-06-01

    In order to obtain tunable unidirectional device, we assumed an ideal periodic layered Parity-Time (PT) symmetry structure inserted by doped LiNbO3 (LN) interlayers. LN is a typical electro-optical material of which the refractive index depends on the external electric field. In our work, we theoretically investigate the modulation effect of the external electric field on the transmittance and reflectance of the structure through numerical method. Through selected structural parameters, the one-way enhanced reflection and high absorption (above 0.9) behaviors are found. Within a special frequency band (not a single frequency), our theoretical model performs enhanced reflection in one incidence direction and high absorption in the other direction. Furthermore, the directions of enhanced reflection and absorption can be reversed through reversing the direction of applied electric field. Such structure with reversible properties has the potential in designing new optical devices.

  7. Nonlinear refraction at the absorption edge in InAs.

    PubMed

    Poole, C D; Garmire, E

    1984-08-01

    The results of measurements of nonlinear refraction at the absorption edge in InAs between 68 and 90 K taken with an HF laser are compared with those of a band-gap resonant model in which the contribution of the light-hole band is included and found to account for more than 40% of the observed nonlinear refraction. A generalized expression for the nonlinear index is derived by using the complete Fermi-Dirac distribution function. Good agreement between theory and experiment is obtained, with no free parameters.

  8. Quasar Absorption Studies

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  9. [Comparative study of theoretical literature on cold pathogenic disease in Wai tai mi yao fang (Arcane Essentials from the Imperial Library) and Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief)].

    PubMed

    Zhang, Huirui; Liang, Yongxuan

    2014-09-01

    In the Wai tai mi yao fang (Arcane Essentials from the Imperial Library) compiled in 752, its portion on cold pathogenic disorders embodies the achievements before the mid Tang Dynasty, whereas that in the Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief), compiled in 992 embodies those before the early Song Dynasty. Comparison on the theory of cold disorders in both books reveal that, during the 2 centuries period from mid Tang to early Song Dynasties, the texts as a carrier for the transmission of such theory in both show no distinct changes, but only with minor revisions and improvements.

  10. Dispersion dependence of second-order refractive index and complex third-order optical susceptibility in oxide glasses

    NASA Astrophysics Data System (ADS)

    Abdel Wahab, F. A.; El-Diasty, Fouad; Abdel-Baki, Manal

    2009-10-01

    A method correlates Fresnel-based spectrophotometric measurements and Lorentz dispersion theory is presented to study the dispersion of nonlinear optical parameters in particularly oxide glasses in a very wide range of angular frequency. The second-order refractive index and third-order optical susceptibility of Cr-doped glasses are determined from linear refractive index. Furthermore, both real and imaginary components of the complex susceptibility are carried out. The study reveals the importance of determining the dispersion of nonlinear absorption (two-photon absorption coefficient) to find the maximum resonant and nonresonant susceptibilities of investigated glasses. The present method is applied on Cr-doped lithium aluminum silicate (LAS) glasses due to their semiconductor-like behavior and also to their application in laser industry.

  11. Fat-soluble vitamin intestinal absorption: absorption sites in the intestine and interactions for absorption.

    PubMed

    Goncalves, Aurélie; Roi, Stéphanie; Nowicki, Marion; Dhaussy, Amélie; Huertas, Alain; Amiot, Marie-Josèphe; Reboul, Emmanuelle

    2015-04-01

    The interactions occurring at the intestinal level between the fat-soluble vitamins A, D, E and K (FSVs) are poorly documented. We first determined each FSV absorption profile along the duodenal-colonic axis of mouse intestine to clarify their respective absorption sites. We then investigated the interactions between FSVs during their uptake by Caco-2 cells. Our data show that vitamin A was mostly absorbed in the mouse proximal intestine, while vitamin D was absorbed in the median intestine, and vitamin E and K in the distal intestine. Significant competitive interactions for uptake were then elucidated among vitamin D, E and K, supporting the hypothesis of common absorption pathways. Vitamin A also significantly decreased the uptake of the other FSVs but, conversely, its uptake was not impaired by vitamins D and K and even promoted by vitamin E. These results should be taken into account, especially for supplement formulation, to optimise FSV absorption. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors

    NASA Astrophysics Data System (ADS)

    Wang, Kangpeng; Feng, Yanyan; Chang, Chunxia; Zhan, Jingxin; Wang, Chengwei; Zhao, Quanzhong; Coleman, Jonathan N.; Zhang, Long; Blau, Werner J.; Wang, Jun

    2014-08-01

    A series of layered molybdenum dichalcogenides, i.e., MoX2 (X = S, Se and Te), were prepared in cyclohexyl pyrrolidinone by a liquid-phase exfoliation technique. The high quality of the two-dimensional nanostructures was verified by transmission electron microscopy and absorption spectroscopy. Open- and closed-aperture Z-scans were employed to study the nonlinear absorption and nonlinear refraction of the MoX2 dispersions, respectively. All the three-layered nanostructures exhibit prominent ultrafast saturable absorption (SA) for both femtosecond (fs) and picosecond (ps) laser pulses over a broad wavelength range from the visible to the near infrared. While the dispersions treated with low-speed centrifugation (1500 rpm) have an SA response, and the MoS2 and MoSe2 dispersions after higher speed centrifugation (10 000 rpm) possess two-photon absorption for fs pulses at 1030 nm, which is due to the significant reduction of the average thickness of the nanosheets; hence, the broadening of band gap. In addition, all dispersions show obvious nonlinear self-defocusing for ps pulses at both 1064 nm and 532 nm, resulting from the thermally-induced nonlinear refractive index. The versatile ultrafast nonlinear properties imply a huge potential of the layered MoX2 semiconductors in the development of nanophotonic devices, such as mode-lockers, optical limiters, optical switches, etc.A series of layered molybdenum dichalcogenides, i.e., MoX2 (X = S, Se and Te), were prepared in cyclohexyl pyrrolidinone by a liquid-phase exfoliation technique. The high quality of the two-dimensional nanostructures was verified by transmission electron microscopy and absorption spectroscopy. Open- and closed-aperture Z-scans were employed to study the nonlinear absorption and nonlinear refraction of the MoX2 dispersions, respectively. All the three-layered nanostructures exhibit prominent ultrafast saturable absorption (SA) for both femtosecond (fs) and picosecond (ps) laser pulses over a broad

  13. The absorption Ångström exponent of black carbon: from numerical aspects

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Eddy Chung, Chul; Yin, Yan; Schnaiter, Martin

    2018-05-01

    The absorption Ångström exponent (AAE) is an important aerosol optical parameter used for aerosol characterization and apportionment studies. The AAE of black carbon (BC) particles is widely accepted to be 1.0, although observational estimates give quite a wide range of 0.6-1.3. With considerable uncertainties related to observations, a numerical study is a powerful method, if not the only one, to provide a better and more accurate understanding on BC AAE. This study calculates BC AAE using realistic particle geometries based on fractal aggregate and an accurate numerical optical model (namely the multiple-sphere T-matrix method), and considers bulk properties of an ensemble of BC particles following lognormal size distributions. At odds with the expectations, BC AAE is not 1.0, even when BC is assumed to have small sizes and a wavelength-independent refractive index. With a wavelength-independent refractive index, the AAE of fresh BC is approximately 1.05 and relatively insensitive to particle size. For BC with geometric mean diameters larger than 0.12 µm, BC AAE becomes smaller when BC particles are aged (compact structures or coated by other non-absorptive materials). For coated BC, we prescribe the coating fraction variation based on a laboratory study, where smaller BC cores are shown to develop larger coating fractions than those of bigger BC cores. For both compact and coated BC, the AAE is highly sensitive to particle size distribution, ranging from approximately 0.8 to even over 1.4 with wavelength-independent refractive index. When the refractive index is allowed to vary with wavelength, a feature with observational backing, the BC AAE may show an even wider range. For different BC morphologies, we derive simple empirical equations on BC AAE based on our numerical results, which can serve as a guide for the response of BC AAE to BC size and refractive index. Due to its complex influences, the effects of BC geometry is better to be discussed at certain

  14. Scattering and Absorption Properties of Biomaterials for Dental Restorative Applications

    NASA Astrophysics Data System (ADS)

    Fernandez-Oliveras, A.; Rubiño, M.; Pérez, M. M.

    2013-08-01

    The physical understanding of the optical properties of dental biomaterials is mandatory for their final success in restorative applications.Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function,the refractive index, and the surface conditions (roughness). We have employed the inverse adding-doubling (IAD) method to combine transmittance and reflectance measurements performed using an integrating-sphere setup with the results of the previous scattering-anisotropygoniometric measurements. This has led to the determination of the absorption and the scattering coefficients. The aim was to optically characterize two different dental-resin composites (nanocomposite and hybrid) and one type of zirconia ceramic, and comparatively study them. The experimental procedure was conducted under repeatability conditions of measurement in order to determine the uncertainty associated to the optical properties of the biomaterials. Spectral variations of the refraction index and the scattering anisotropy factor were also considered. The whole experimental procedure fulfilled all the necessary requirements to provide optical-property values with lower associated uncertainties. The effective transport coefficient presented a similar spectral behavior for the two composites but completely different for the zirconia ceramic. The results demonstrated that the scattering anisotropy exerted a clearly distinct impact on the optical properties of the zirconia ceramic compared with those of the dental-resin composites.

  15. Dyadic Short Forms of the Wechsler Adult Intelligence Scale-IV.

    PubMed

    Denney, David A; Ringe, Wendy K; Lacritz, Laura H

    2015-08-01

    Full Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) administration can be time-consuming and may not be necessary when intelligence quotient estimates will suffice. Estimated Full Scale Intelligence Quotient (FSIQ) and General Ability Index (GAI) scores were derived from nine dyadic short forms using individual regression equations based on data from a clinical sample (n = 113) that was then cross validated in a separate clinical sample (n = 50). Derived scores accounted for 70%-83% of the variance in FSIQ and 77%-88% of the variance in GAI. Predicted FSIQs were strongly associated with actual FSIQ (rs = .73-.88), as were predicted and actual GAIs (rs = .80-.93). Each of the nine dyadic short forms of the WAIS-IV was a good predictor of FSIQ and GAI in the validation sample. These data support the validity of WAIS-IV short forms when time is limited or lengthier batteries cannot be tolerated by patients. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. [A multilevel model analysis of correlation between population characteristics and work ability of employees].

    PubMed

    Zhang, Lei; Huang, Chunping; Lan, Yajia; Wang, Mianzhen

    2015-12-01

    To analyze the correlation between population characteristics and work ability of employees with a multilevel model, to investigate the important influencing factors for work ability, and to provide a basis for improvement in work ability. Work ability index (WAI)was applied to measure the work ability of 1686 subjects from different companies (n=6). MLwi N2.0 software was applied for two-level variance component model fitting. The WAI of employees showed differences between various companies (χ2=3.378 6, P=0.0660); working years was negatively correlated with WAI (χ2=38.229 2, P=0.0001), and the WAI of the employees with 20 or more working years was 1.63 lower than that of the employees with less than 20 working years; the work ability of manual workers was lower than that of mental-manual workers (χ2=8.2726, P=0.0040), and the work ability showed no significant difference between mental workers and mental-manual workers (χ2=2.086 0, P=0.148 7). From the perspective of probability, the multilevel model analysis reveals the differences in work ability of employees between different companies, and suggests that company, work type, and working years are the important influencing factors for work ability of employees. These factors should be improved and adjusted to protect or enhance the work ability of employees.

  17. Measuring Work Ability with Its Antecedents: Evaluation of the Work Ability Survey.

    PubMed

    Voltmer, Jan-Bennet; Deller, Jürgen

    2017-07-24

    Purpose The revised version of the Work Ability Survey (WAS-R) assesses work ability on several sub-scales at the intersection of personal and organizational capacity, thus adding to the measurement of work ability by integrating the holistic model. It, therefore, improves on two features of the current standard measurement tool of work ability, the Work Ability Index (WAI): (1) a ceiling effect and (2) limited detail due to a focus on physical health and personal capacity. Method In two samples (n 1  = 1093, n 2  = 359), psychometric properties and the structure of the WAS-R were analyzed. To evaluate construct validity, inter-correlations of the WAS-R and WAI, sickness absence, expected and desired retirement age, and post-retirement work intention were calculated. Results The WAS-R was found to be distributed closer to normality than the WAI. The structural analyses yielded acceptable results for the hypothesized model. The WAS-R was adequately correlated with the WAI, negatively with sickness absence, and positively with desired retirement age. Conclusions The WAS-R extends the measurement of work ability, reflecting organizations' work demands. Its broad sub-scales lead to high acceptance of the results within the participating companies. In particular, the organizational capacity scales can be used to guide interventions aiming at organizational characteristics to improve work ability.

  18. Can we improve the clinical assessment of working memory? An evaluation of the Wechsler Adult Intelligence Scale-Third Edition using a working memory criterion construct.

    PubMed

    Hill, B D; Elliott, Emily M; Shelton, Jill T; Pella, Russell D; O'Jile, Judith R; Gouvier, W Drew

    2010-03-01

    Working memory is the cognitive ability to hold a discrete amount of information in mind in an accessible state for utilization in mental tasks. This cognitive ability is impaired in many clinical populations typically assessed by clinical neuropsychologists. Recently, there have been a number of theoretical shifts in the way that working memory is conceptualized and assessed in the experimental literature. This study sought to determine to what extent the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Working Memory Index (WMI) measures the construct studied in the cognitive working memory literature, whether an improved WMI could be derived from the subtests that comprise the WAIS-III, and what percentage of variance in individual WAIS-III subtests is explained by working memory. It was hypothesized that subtests beyond those currently used to form the WAIS-III WMI would be able to account for a greater percentage of variance in a working memory criterion construct than the current WMI. Multiple regression analyses (n = 180) revealed that the best predictor model of subtests for assessing working memory was composed of the Digit Span, Letter-Number Sequencing, Matrix Reasoning, and Vocabulary. The Arithmetic subtest was not a significant contributor to the model. These results are discussed in the context of how they relate to Unsworth and Engle's (2006, 2007) new conceptualization of working memory mechanisms.

  19. Item response theory analysis of Working Alliance Inventory, revised response format, and new Brief Alliance Inventory.

    PubMed

    Mallinckrodt, Brent; Tekie, Yacob T

    2016-11-01

    The Working Alliance Inventory (WAI) has made great contributions to psychotherapy research. However, studies suggest the 7-point response format and 3-factor structure of the client version may have psychometric problems. This study used Rasch item response theory (IRT) to (a) improve WAI response format, (b) compare two brief 12-item versions (WAI-sr; WAI-s), and (c) develop a new 16-item Brief Alliance Inventory (BAI). Archival data from 1786 counseling center and community clients were analyzed. IRT findings suggested problems with crossed category thresholds. A rescoring scheme that combines neighboring responses to create 5- and 4-point scales sharply reduced these problems. Although subscale variance was reduced by 11-26%, rescoring yielded improved reliability and generally higher correlations with therapy process (session depth and smoothness) and outcome measures (residual gain symptom improvement). The 16-item BAI was designed to maximize "bandwidth" of item difficulty and preserve a broader range of WAI sensitivity than WAI-s or WAI-sr. Comparisons suggest the BAI performed better in several respects than the WAI-s or WAI-sr and equivalent to the full WAI on several performance indicators.

  20. Old stellar populations. 5: Absorption feature indices for the complete LICK/IDS sample of stars

    NASA Technical Reports Server (NTRS)

    Worthey, Guy; Faber, S. M.; Gonzalez, J. Jesus; Burstein, D.

    1994-01-01

    Twenty-one optical absorption features, 11 of which have been previously defined, are automatically measured in a sample of 460 stars. Following Gorgas et al., the indices are summarized in fitting functions that give index strengths as functions of stellar temperature, gravity, and (Fe/H). This project was carried out with the purpose of predicting index strengths in the integrated light of stellar populations of different ages and metallicities, but the data should be valuable for stellar studies in the Galaxy as well. Several of the new indices appear to be promising indicators of metallicity for old stellar populations. A complete list of index data and atmospheric parameters is available in computer-readable form.

  1. Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors.

    PubMed

    Wang, Kangpeng; Feng, Yanyan; Chang, Chunxia; Zhan, Jingxin; Wang, Chengwei; Zhao, Quanzhong; Coleman, Jonathan N; Zhang, Long; Blau, Werner J; Wang, Jun

    2014-09-21

    A series of layered molybdenum dichalcogenides, i.e., MoX₂ (X = S, Se and Te), were prepared in cyclohexyl pyrrolidinone by a liquid-phase exfoliation technique. The high quality of the two-dimensional nanostructures was verified by transmission electron microscopy and absorption spectroscopy. Open- and closed-aperture Z-scans were employed to study the nonlinear absorption and nonlinear refraction of the MoX₂ dispersions, respectively. All the three-layered nanostructures exhibit prominent ultrafast saturable absorption (SA) for both femtosecond (fs) and picosecond (ps) laser pulses over a broad wavelength range from the visible to the near infrared. While the dispersions treated with low-speed centrifugation (1500 rpm) have an SA response, and the MoS₂ and MoSe₂ dispersions after higher speed centrifugation (10,000 rpm) possess two-photon absorption for fs pulses at 1030 nm, which is due to the significant reduction of the average thickness of the nanosheets; hence, the broadening of band gap. In addition, all dispersions show obvious nonlinear self-defocusing for ps pulses at both 1064 nm and 532 nm, resulting from the thermally-induced nonlinear refractive index. The versatile ultrafast nonlinear properties imply a huge potential of the layered MoX2 semiconductors in the development of nanophotonic devices, such as mode-lockers, optical limiters, optical switches, etc.

  2. Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity.

    PubMed

    Paramsothy, Pathmaja; Knopp, Robert H; Kahn, Steven E; Retzlaff, Barbara M; Fish, Brian; Ma, Lina; Ostlund, Richard E

    2011-11-01

    The rise in LDL with egg feeding in lean insulin-sensitive (LIS) participants is 2- and 3-fold greater than in lean insulin-resistant (LIR) and obese insulin-resistant (OIR) participants, respectively. We determined whether differences in cholesterol absorption, synthesis, or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis. Plasma sterols were measured by gas chromatography-mass spectrometry in a random subset of 34 LIS, 37 LIR, and 37 OIR participants defined by the insulin sensitivity index (S(I)) and by BMI criteria selected from a parent group of 197 participants. Cholestanol and plant sterols provide a measure of cholesterol absorption, and lathosterol provides a measure of cholesterol synthesis. The mean (±SD) ratio of plasma total absorption biomarker sterols to cholesterol was 4.48 ± 1.74 in LIS, 3.25 ± 1.06 in LIR, and 2.82 ± 1.08 in OIR participants. After adjustment for age and sex, the relations of the absorption sterol-cholesterol ratios were as follows: LIS > OIR (P < 0.001), LIS > LIR (P < 0.001), and LIR > OIR (P = 0.11). Lathosterol-cholesterol ratios were 0.71 ± 0.32 in the LIS participants, 0.95 ± 0.47 in the LIR participants, and 1.29 ± 0.55 in the OIR participants. After adjustment for age and sex, the relations of lathosterol-cholesterol ratios were as follows: LIS < OIR (P < 0.001), LIS < LIR (P = 0.03), and LIR < OIR (P = 0.002). Total sterol concentrations were positively associated with S(I) and negatively associated with obesity, whereas lathosterol correlations were the opposite. Cholesterol absorption was highest in the LIS participants, whereas cholesterol synthesis was highest in the LIR and OIR participants. Therapeutic diets for hyperlipidemia should emphasize low-cholesterol diets in LIS persons and weight loss to improve S(I) and to decrease cholesterol overproduction in LIR and OIR persons.

  3. The relationship between physical activity and work ability - A cross-sectional study of teachers.

    PubMed

    Grabara, Małgorzata; Nawrocka, Agnieszka; Powerska-Didkowska, Aneta

    2018-01-01

    To assess relationship between physical activity (PA) and perceived work ability amongst teachers from the Upper Silesia, Poland. The study involved 171 teachers (129 women, 42 men) of primary and secondary schools of the Upper Silesia, Poland. Physical education teachers were excluded from the study. The level of PA was estimated using the International Physical Activity Questionnaire short version, and perceived work ability was estimated using Work Ability Index (WAI). Male teachers had significantly higher levels of vigorous-intensity PA, moderateintensity PA, and total weekly PA than female teachers. The recommendations of the World Health Organization (WHO) met 46% of studied women and 74% of men. Work ability did not differ between male and female teachers. Work ability was related to age, body mass index (BMI), and PA (vigorous-intensity PA, moderate-intensity PA, total weekly PA). The female teachers with excellent or good WAI had significantly higher levels of vigorous-intensity PA, moderate-intensity PA and total weekly PA than female teachers with moderate or poor WAI. The teachers involving in high or moderate intensity PA could improve their work ability. Further studies should focus on relation between physical activity and work ability among teachers of various age and seniority, from both, urban and rural schools. Int J Occup Med Environ Health 2018;31(1):1-9. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  4. STELAR: An experiment in the electronic distribution of astronomical literature

    NASA Technical Reports Server (NTRS)

    Warnock, A.; Vansteenburg, M. E.; Brotzman, L. E.; Gass, J.; Kovalsky, D.

    1992-01-01

    STELAR (Study of Electronic Literature for Astronomical Research) is a Goddard-based project designed to test methods of delivering technical literature in machine readable form. To that end, we have scanned a five year span of the ApJ, ApJ Supp, AJ and PASP, and have obtained abstracts for eight leading academic journals from NASA/STI CASI, which also makes these abstracts available through the NASA RECON system. We have also obtained machine readable versions of some journal volumes from the publishers, although in many instances, the final typeset versions are no longer available. The fundamental data object for the STELAR database is the article, a collection of items associated with a scientific paper - abstract, scanned pages (in a variety of formats), figures, OCR extractions, forward and backward references, errata and versions of the paper in various formats (e.g., TEX, SGML, PostScript, DVI). Articles are uniquely referenced in the database by journal name, volume number and page number. The selection and delivery of articles is accomplished through the WAIS (Wide Area Information Server) client/server models requiring only an Internet connection. Modest modifications to the server code have made it capable of delivering the multiple data types required by STELAR. WAIS is a platform independent and fully open multi-disciplinary delivery system, originally developed by Thinking Machines Corp. and made available free of charge. It is based on the ISO Z39.50 standard communications protocol. WAIS servers run under both UNIX and VMS. WAIS clients run on a wide variety of machines, from UNIX-based Xwindows systems to MS-DOS and macintosh microcomputers. The WAIS system includes full-test indexing and searching of documents, network interface and easy access to a variety of document viewers. ASCII versions of the CASI abstracts have been formatted for display and the full test of the abstracts has been indexed. The entire WAIS database of abstracts is now

  5. Investigation of the refractive index repeatability for tantalum pentoxide coatings, prepared by physical vapor film deposition techniques.

    PubMed

    Stenzel, O; Wilbrandt, S; Wolf, J; Schürmann, M; Kaiser, N; Ristau, D; Ehlers, H; Carstens, F; Schippel, S; Mechold, L; Rauhut, R; Kennedy, M; Bischoff, M; Nowitzki, T; Zöller, A; Hagedorn, H; Reus, H; Hegemann, T; Starke, K; Harhausen, J; Foest, R; Schumacher, J

    2017-02-01

    Random effects in the repeatability of refractive index and absorption edge position of tantalum pentoxide layers prepared by plasma-ion-assisted electron-beam evaporation, ion beam sputtering, and magnetron sputtering are investigated and quantified. Standard deviations in refractive index between 4*10-4 and 4*10-3 have been obtained. Here, lowest standard deviations in refractive index close to our detection threshold could be achieved by both ion beam sputtering and plasma-ion-assisted deposition. In relation to the corresponding mean values, the standard deviations in band-edge position and refractive index are of similar order.

  6. Absorption in X-ray spectra of high-redshift quasars

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Fiore, Fabrizio; Wilkes, Belinda; Mcdowell, Jonathan; Bechtold, Jill

    1994-01-01

    We present evidence that X-ray absorption is common in high-redshift quasars. We have studied six high-redshift (z approximately 3) quasars with the ROSAT Position Sensitive Proportional Counter (PSPC) of which four are in directions of low Galactic N(sub H). Three out of these four show excess absorption, while only three in approximately 50 z approximately less than 0.4 quasars do, indicating that such absorption must be common, but not ubiquitous, at high redshifts, and that the absorbers must lie at z greater than 0.4. The six quasars were: S5 0014+81, Q0420-388, PKS 0438-436, S4 0636+680. PKS 2000-330, PKS 2126-158, which have redshifts between 2.85 and 3.78. PKS 0438-436 and PKS 2126-158 show evidence for absorption above the local Galactic value at better than 99.999% confidence level. If the absorber is at the redshift of the quasar, then values of N(sub H) = (0.86(+0.49, -0.28)) x 10(exp 22) atoms/sq cm for PKS 0438-436, and N(sub H) = (1.45(+1.20, -0.64)) x 10(exp 22) atoms/ sq cm for PKS 2126-158, are implied, assuming solar abundances. The spectrum of S4 0636+680 also suggests the presence of a similarly large absorption column density at the 98% confidence level. This absorption reverses the trend for the most luminous active galactic nuclei (AGN) to have the least X-ray absorption, so a new mechanism is likely to be responsible. Intervening absorption due to damped Lyman(alpha) systems is a plausible cause. We also suggest, as an intrinsic model, that intracluster material, e.g., a cooling flow, around the quasar could account for both the X-ray spectrum and other properties of these quasars. All the quasars are radio-loud and three are gigahertz peaked (two of the three showing absorption). No excess absorption above the Galactic value is seen toward Q0420-388. This quasar has two damped Lyman(alpha) systems at z = 3.08. The limit on the X-ray column density implies a low ionization fraction, N(H I)/N(H) approximately greater than 4 x 10(exp -3) (3

  7. Application of the laser induced deflection (LID) technique for low absorption measurements in bulk materials and coatings

    NASA Astrophysics Data System (ADS)

    Triebel, W.; Mühlig, C.; Kufert, S.

    2005-10-01

    Precise absorption measurements of bulk materials and coatings upon pulsed ArF laser irradiation are presented using a compact experimental setup based on the laser induced deflection technique (LID). For absorption measurements of bulk materials the influence of pure bulk and pure surface absorption on the temperature and refractive index profile and thus for the probe beam deflection is analyzed in detail. The separation of bulk and surface absorption via the commonly used variation of the sample thickness is carried out for fused silica and calcium fluoride. The experimental results show that for the given surface polishing quality the bulk absorption coefficient of fused silica can be obtained by investigating only one sample. To avoid the drawback of different bulk and surface properties amongst a thickness series, we propose a strategy based on the LID technique to generally obtain surface and bulk absorption separately by investigating only one sample. Apart from measuring bulk absorption coefficients the LID technique is applied to determine the absorption of highly reflecting (HR) coatings on CaF2 substrates. Beside the measuring strategy the experimental results of a AlF3/LaF3 based HR coating are presented. In order to investigate a larger variety of coatings, including high transmitting coatings, a general measuring strategy based on the LID technique is proposed.

  8. 69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  9. Determination of Scattering and Absorption Coefficients for Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Spuckler, Charles M.; Markham, James R.

    2009-01-01

    The temperature dependence of the scattering and absorption coefficients for a set of freestanding plasma-sprayed 8 wt% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) was determined at temperatures up to 1360 C in a wavelength range from 1.2 micrometers up to the 8YSZ absorption edge. The scattering and absorption coefficients were determined by fitting the directional-hemispherical reflectance and transmittance values calculated by a four-flux Kubelka Munk method to the experimentally measured hemispherical-directional reflectance and transmittance values obtained for five 8YSZ thicknesses. The scattering coefficient exhibited a continuous decrease with increasing wavelength and showed no significant temperature dependence. The scattering is primarily attributed to the relatively temperature-insensitive refractive index mismatch between the 8YSZ and its internal voids. The absorption coefficient was very low (less than 1 per centimeter) at wavelengths between 2 micrometers and the absorption edge and showed a definite temperature dependence that consisted of a shift of the absorption edge to shorter wavelengths and an increase in the weak absorption below the absorption edge with increasing temperature. The shift in the absorption edge with temperature is attributed to strongly temperature-dependent multiphonon absorption. While TBC hemispherical transmittance beyond the absorption edge can be predicted by a simple exponential decrease with thickness, below the absorption edge, typical TBC thicknesses are well below the thickness range where a simple exponential decrease in hemispherical transmittance with TBC thickness is expected. [Correction added after online publication August 11, 2009: "edge to a shorter wavelengths" has been updated as edge to shorter wavelengths."

  10. X-ray absorption spectroscopy: EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Structure)

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

    Alp, E.E.; Mini, S.M.; Ramanathan, M.

    1990-04-01

    The x-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. It has also played an important role in the discovery and systematization of rare-earth elements. The discovery of synchrotron radiation in 1952, and later the availability of broadly tunable synchrotron based x-ray sources have revitalized this technique since the 1970's. The correct interpretation of the oscillatory structure in the x-ray absorption cross-section above the absorption edge by Sayers et. al. has transformed XAS from a spectroscopic tool to a structural technique. EXAFS (Extended X-raymore » Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. An excellent description of the principles and data analysis techniques of EXAFS is given by Teo. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles. Today, there are about 50 experimental stations in various synchrotrons around the world dedicated to collecting x-ray absorption data from the bulk and surfaces of solids and liquids. In this chapter, we will give the basic principles of XAS, explain the information content of essentially two different aspects of the absorption process leading to EXAFS and XANES, and discuss the source and samples limitations.« less

  11. Measurement of the complex refractive index and complex dielectric permittivity of T.P.S. Space Shuttle tile materials at millimeter wavelengths

    NASA Technical Reports Server (NTRS)

    Afsar, Mohammed Nurul; Chi, Hua; Li, Xiaohui

    1990-01-01

    Complex refractive index and dielectric permittivity studies of presently used Space Shuttle tile materials at millimeter wavelengths reveal these tiles to exhibit similar absorption characteristics to those of fused silica materials. This absorption is mainly related to the water content in the specimen. A strong birefringence is observed at least in one of these fibrous refractory composite materials.

  12. Relative importance of black carbon, brown carbon, and absorption enhancement from clear coatings in biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Pokhrel, Rudra P.; Beamesderfer, Eric R.; Wagner, Nick L.; Langridge, Justin M.; Lack, Daniel A.; Jayarathne, Thilina; Stone, Elizabeth A.; Stockwell, Chelsea E.; Yokelson, Robert J.; Murphy, Shane M.

    2017-04-01

    A wide range of globally significant biomass fuels were burned during the fourth Fire Lab at Missoula Experiment (FLAME-4). A multi-channel photoacoustic absorption spectrometer (PAS) measured dry absorption at 405, 532, and 660 nm and thermally denuded (250 °C) absorption at 405 and 660 nm. Absorption coefficients were broken into contributions from black carbon (BC), brown carbon (BrC), and lensing following three different methodologies, with one extreme being a method that assumes the thermal denuder effectively removes organics and the other extreme being a method based on the assumption that black carbon (BC) has an Ångström exponent of unity. The methodologies employed provide ranges of potential importance of BrC to absorption but, on average, there was a difference of a factor of 2 in the ratio of the fraction of absorption attributable to BrC estimated by the two methods. BrC absorption at shorter visible wavelengths is of equal or greater importance to that of BC, with maximum contributions of up to 92 % of total aerosol absorption at 405 nm and up to 58 % of total absorption at 532 nm. Lensing is estimated to contribute a maximum of 30 % of total absorption, but typically contributes much less than this. Absorption enhancements and the estimated fraction of absorption from BrC show good correlation with the elemental-carbon-to-organic-carbon ratio (EC / OC) of emitted aerosols and weaker correlation with the modified combustion efficiency (MCE). Previous studies have shown that BrC grows darker (larger imaginary refractive index) as the ratio of black to organic aerosol (OA) mass increases. This study is consistent with those findings but also demonstrates that the fraction of total absorption attributable to BrC shows the opposite trend: increasing as the organic fraction of aerosol emissions increases and the EC / OC ratio decreases.

  13. Measurement method for the refractive index of thick solid and liquid layers.

    PubMed

    Santić, Branko; Gracin, Davor; Juraić, Krunoslav

    2009-08-01

    A simple method is proposed for the refractive index measurement of thick solid and liquid layers. In contrast to interferometric methods, no mirrors are used, and the experimental setup is undemanding and simple. The method is based on the variation of transmission caused by optical interference within the layer as a function of incidence angle. A new equation is derived for the positions of the interference extrema versus incidence angle. Scattering at the surfaces and within the sample, as well as weak absorption, do not play important roles. The method is illustrated by the refractive index measurements of sapphire, window glass, and water.

  14. Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity1234

    PubMed Central

    Knopp, Robert H; Kahn, Steven E; Retzlaff, Barbara M; Fish, Brian; Ma, Lina; Ostlund, Richard E

    2011-01-01

    Background: The rise in LDL with egg feeding in lean insulin-sensitive (LIS) participants is 2- and 3-fold greater than in lean insulin-resistant (LIR) and obese insulin-resistant (OIR) participants, respectively. Objective: We determined whether differences in cholesterol absorption, synthesis, or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis. Design: Plasma sterols were measured by gas chromatography–mass spectrometry in a random subset of 34 LIS, 37 LIR, and 37 OIR participants defined by the insulin sensitivity index (SI) and by BMI criteria selected from a parent group of 197 participants. Cholestanol and plant sterols provide a measure of cholesterol absorption, and lathosterol provides a measure of cholesterol synthesis. Results: The mean (±SD) ratio of plasma total absorption biomarker sterols to cholesterol was 4.48 ± 1.74 in LIS, 3.25 ± 1.06 in LIR, and 2.82 ± 1.08 in OIR participants. After adjustment for age and sex, the relations of the absorption sterol–cholesterol ratios were as follows: LIS > OIR (P < 0.001), LIS > LIR (P < 0.001), and LIR > OIR (P = 0.11). Lathosterol-cholesterol ratios were 0.71 ± 0.32 in the LIS participants, 0.95 ± 0.47 in the LIR participants, and 1.29 ± 0.55 in the OIR participants. After adjustment for age and sex, the relations of lathosterol-cholesterol ratios were as follows: LIS < OIR (P < 0.001), LIS < LIR (P = 0.03), and LIR < OIR (P = 0.002). Total sterol concentrations were positively associated with SI and negatively associated with obesity, whereas lathosterol correlations were the opposite. Conclusions: Cholesterol absorption was highest in the LIS participants, whereas cholesterol synthesis was highest in the LIR and OIR participants. Therapeutic diets for hyperlipidemia should emphasize low-cholesterol diets in LIS persons and weight loss to improve SI and to decrease cholesterol overproduction in LIR and OIR

  15. Drought Assessment over the Four Major River Basins of India using GRACE-based estimates of Water Availability

    NASA Astrophysics Data System (ADS)

    Sinha, D.; Syed, T. H.

    2017-12-01

    Drought is a natural disaster that has mutilating consequences over agriculture, ecosystems, economy and the society. Over the past few decades, drought related catastrophe, associated with global climate change, has escalated all across the world. Identification and analysis of drought utilizing individual hydrologic variables may be inadequate owing to the multitude of factors that are associated with the phenomenon. Therefore it is crucial to develop techniques that warrant comprehensive monitoring and assessment of droughts. In this study we propose a novel drought index (Water Availability Index (WAI)) that comprehends all the aspects of meteorologic, agricultural and hydrologic droughts. The proposed framework underscores the conceptualization and utilization of water availability, quantified as an integrated estimate of land water storage, using Gravity Recovery and Climate Experiment (GRACE) observations, and precipitation. The methodology is employed over four major river basins of India (i.e. Ganga, Krishna, Godavari and Mahanadi) for a period of 155 months (April 2002 to February 2015). Results exhibit the potential of the propounded index (WAI) to recognize drought events and impart insightful quantification of drought severity. WAI also demonstrates enhanced outcomes in comparison to other commonly used drought indices like PDSI, SPI, SPEI and SRI. In general there are at least three major drought periods with intensities ranging from moderate to severe in almost all river basins. The longest drought period, extending for 27 months, from September 2008 to November 2010, is observed in the Mahanadi basin. Results from this study confirm the potential of this technique as an effective tool for the characterization of drought at large spatial scales, which will only excel with better quantification and extended availability of terrestrial water storage observations from the GRACE-Follow On mission.

  16. Optical Kerr effect and two-photon absorption in monolayer black phosphorus

    NASA Astrophysics Data System (ADS)

    Margulis, Vl A.; Muryumin, E. E.; Gaiduk, E. A.

    2018-05-01

    A theoretical treatment of nonlinear refraction and two-photon absorption is presented for a novel two-dimensional material, monolayer black phosphorus (or phosphorene), irradiated by a normally incident and linearly polarized coherent laser beam of frequency ω. It is found that both the nonlinear refractive index n 2(ω) and the two-photon absorption coefficient α 2(ω) of phosphorene depend upon the polarization of the radiation field relative to phosphorene’s crystallographic axes. For the two principal polarization directions considered—viz, the armchair ({ \\mathcal A }{ \\mathcal C }) and zigzag ({ \\mathcal Z }{ \\mathcal Z }), the calculated values of n 2 and α 2 are distinguished by the order of their magnitude, with the n 2 and α 2 values being greater for the { \\mathcal A }{ \\mathcal C } direction. Furthermore, for almost all the incident photon energies below the fundamental absorption edge, except its neighborhood, the signs of n 2 as well as α 2 for the { \\mathcal A }{ \\mathcal C } and { \\mathcal Z }{ \\mathcal Z } polarization directions are opposed to each other. Also, for both the directions, the change of sign of n 2 is predicted to occur in the way between the two-photon absorption edge and the fundamental absorption edge, as well as in the near vicinity of the latter, where the Kerr nonlinearity has a pronounced resonant character and the magnitude of n 2 for the { \\mathcal A }{ \\mathcal C } and { \\mathcal Z }{ \\mathcal Z } polarization directions reaches its largest positive values of the order of 10‑9 and 10‑10 cm2 W‑1, respectively. The implications of the findings for practical all-optical switching applications are discussed.

  17. Variability in Wechsler Adult Intelligence Scale-IV subtest performance across age.

    PubMed

    Wisdom, Nick M; Mignogna, Joseph; Collins, Robert L

    2012-06-01

    Normal Wechsler Adult Intelligence Scale (WAIS)-IV performance relative to average normative scores alone can be an oversimplification as this fails to recognize disparate subtest heterogeneity that occurs with increasing age. The purpose of the present study is to characterize the patterns of raw score change and associated variability on WAIS-IV subtests across age groupings. Raw WAIS-IV subtest means and standard deviations for each age group were tabulated from the WAIS-IV normative manual along with the coefficient of variation (CV), a measure of score dispersion calculated by dividing the standard deviation by the mean and multiplying by 100. The CV further informs the magnitude of variability represented by each standard deviation. Raw mean scores predictably decreased across age groups. Increased variability was noted in Perceptual Reasoning and Processing Speed Index subtests, as Block Design, Matrix Reasoning, Picture Completion, Symbol Search, and Coding had CV percentage increases ranging from 56% to 98%. In contrast, Working Memory and Verbal Comprehension subtests were more homogeneous with Digit Span, Comprehension, Information, and Similarities percentage of the mean increases ranging from 32% to 43%. Little change in the CV was noted on Cancellation, Arithmetic, Letter/Number Sequencing, Figure Weights, Visual Puzzles, and Vocabulary subtests (<14%). A thorough understanding of age-related subtest variability will help to identify test limitations as well as further our understanding of cognitive domains which remain relatively steady versus those which steadily decline.

  18. [Dynamics of quickly absorption of the carbon source in wastewater by activated sludge].

    PubMed

    Liu, Hong-Bo; Wen, Xiang-Hua; Zhao, Fang

    2011-09-01

    In this paper, absorption characteristics of organic matter in municipal wastewater by three kinds of activated sludge (carbon-enriching, nitrification and denitrification sludge) were studied, and the absorption kinetic data was checked using three kinds of absorption kinetic equations based on Ritchie rate equation. The objectives of this study were to investigate the absorption mechanism of activated sludge to organic matter in municipal wastewater, and to identify the possibility of reclaiming organic matter by activated sludge. Results indicated that in the early 30 min, absorption process of organic matter by activated sludge was found to be mainly physical adsorption, which could be expressed by the Lagergren single-layer adsorption model. The carbon-enriching sludge had the highest adsorption capacity (COD/SS) which was 60 mg/g but the adsorption rate was lower than that of denitrification sludge. While nitrification sludge had the lowest adsorption rate and higher adsorption capacity compared with denitrification sludge, which was about 35 mg/g. The rates of the fitting index theta(0) of carbon-enriching, nitrification and denitrification sludge were 0.284, 0.777 and 0.923, respectively, which indicated that the sorbed organic matter on the surface of carbon-enriching sludge was the easiest fraction to be washed away. That is, the combination intensity of carbon-enriching sludge and organic matter was the feeblest, which was convenient for carbon-enriching sludge to release sorbed carbon. Furthermore, by fitting with Langmuir model, concentration of organic matter was found to be the key parameter influencing the adsorption capacity of activated sludge, while the influence of temperature was not obvious. The kinetic law of organic matter absorption by activated sludge was developed, which introduces a way to kinetically analyze the removing mechanism of pollutant by activated sludge and provides theoretical base for the reclaiming of nutriments in

  19. Mobbing, stress, and work ability index among physicians in Bosnia and Herzegovina: survey study.

    PubMed

    Pranjić, Nurka; Males-Bilić, Ljiljana; Beganlić, Azijada; Mustajbegović, Jadranka

    2006-10-01

    To assess the frequency of reported mobbing and the association among mobbing, working environment factors, stress, health outcome, personality type, and work ability index in a sample of physicians in Bosnia and Herzegovina. We conducted a questionnaire survey using a validated self-reported questionnaire among 511 physicians in national health sector of Bosnia and Herzegovina. The questions covered five major categories of mobbing behavior. Characteristics of the work, perceived work environment and its effects, stress, health, and satisfaction with work and life were assessed by the standardized abridged form of Occupational Stress Questionnaire (OSQ). A standardized questionnaire Work Ability Index (WAI) was used to determine the relation between mobbing and work ability. Of 511 surveyed physicians, 387 (76%) physicians self-reported mobbing behavior in the working environment and 136 (26%) was exposed to persistent mobbing. More than a half of the physicians experienced threats to their professional status and almost a half felt isolated. Logistic regression analysis showed that lack of motivation, loss of self-esteem, loss of confidence, fatigue, and depressiveness were significantly associated with lack of support from colleagues. Intention to leave work was associated with lack of support from colleagues (OR 2.3, 95% CI, 1.065-3.535; t =4.296, P =0.003) and lack of support from superiors (OR 1.526, 95% CI, 0.976-2.076; t =5.753; P =0.001). Isolation or exclusion and threats to professional status were predictors for mental health symptoms. Persistent mobbing experience was a significant predictor for sick leave. Exposure to persistent threat to professional status and isolation or exclusion as forms of mobbing are associated with mental health disturbances and lack of self-esteem and confidence. Setting up a system of support for physicians exposed to mobbing may have important benefits.

  20. Mobbing, Stress, and Work Ability Index among Physicians in Bosnia and Herzegovina: Survey Study

    PubMed Central

    Pranjić, Nurka; Maleš-Bilić, Ljiljana; Beganlić, Azijada; Mustajbegović, Jadranka

    2006-01-01

    Aim To assess the frequency of reported mobbing and the association among mobbing, working environment factors, stress, health outcome, personality type, and work ability index in a sample of physicians in Bosnia and Herzegovina. Method We conducted a questionnaire survey using a validated self-reported questionnaire among 511 physicians in national health sector of Bosnia and Herzegovina. The questions covered five major categories of mobbing behavior. Characteristics of the work, perceived work environment and its effects, stress, health, and satisfaction with work and life were assessed by the standardized abridged form of Occupational Stress Questionnaire (OSQ). A standardized questionnaire Work Ability Index (WAI) was used to determine the relation between mobbing and work ability. Results Of 511 surveyed physicians, 387 (76%) physicians self-reported mobbing behavior in the working environment and 136 (26%) was exposed to persistent mobbing. More than a half of the physicians experienced threats to their professional status and almost a half felt isolated. Logistic regression analysis showed that lack of motivation, loss of self-esteem, loss of confidence, fatigue, and depressiveness were significantly associated with lack of support from colleagues. Intention to leave work was associated with lack of support from colleagues (OR 2.3, 95% CI, 1.065-3.535, t = 4.296, P = 0.003) and lack of support from superiors (OR 1.526, 95% CI, 0.976-2.076, t = 5.753; P = 0.001). Isolation or exclusion and threats to professional status were predictors for mental health symptoms. Persistent mobbing experience was a significant predictor for sick leave. Conclusion Exposure to persistent threat to professional status and isolation or exclusion as forms of mobbing are associated with mental health disturbances and lack of self-esteem and confidence. Setting up a system of support for physicians exposed to mobbing may have important benefits. PMID:17042067

  1. Reverse saturable absorption studies in polymerized indole - Effect of polymerization in the phenomenal enhancement of third order optical nonlinearity

    NASA Astrophysics Data System (ADS)

    Jayakrishnan, K.; Joseph, Antony; Bhattathiripad, Jayakrishnan; Ramesan, M. T.; Chandrasekharan, K.; Siji Narendran, N. K.

    2016-04-01

    We report our results on the identification of large order enhancement in nonlinear optical coefficients of polymerized indole and its comparative study with reference to its monomer counterpart. Indole monomer shows virtually little third order effects whereas its polymerized version exhibits phenomenal increase in its third order nonlinear optical parameters such as nonlinear refractive index and nonlinear absorption. Open aperture Z-scan trace of polyindole done with Q-switched Nd:YAG laser source (532 nm, 7 ns), shows β value as high as 89 cm/GW at a beam energy of 0.83 GW/cm2. Closed aperture Z-scan done at identical energies reveals nonlinear refractive index of the order of -3.55 × 10-17 m2/W. Band gap measurement of polyindole was done with UV-Vis absorption spectra and compared with that of Indole. FTIR spectra of the monomer and polymerized versions were recorded and relevant bond formations were confirmed from the characteristic peaks. Photo luminescent spectra were investigated to know the emission features of both molecules. Beam energy (I0) versus nonlinear absorption coefficient (β) plot indicates reverse saturable type of absorption behaviour in polyindole molecules. Degenerate Four Wave Mixing (DFWM) plot of polyindole reveals quite a cubic dependence between probe and phase conjugate signal and the resulting χ(3) is comparable with Z-scan results. Optical limiting efficiency of polyindole is comparable with certain derivatives of porphyrins, phthalocyanines and graphene oxides.

  2. Retrieval of Aerosol Absorption Properties from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Torres, Omar; Bhartia, Pawan K.; Jethva, H.; Ahn, Chang-Woo

    2012-01-01

    The Angstrom Absorption Exponent (AAE) is a parameter commonly used to characterize the wavelength-dependence of aerosol absorption optical depth (AAOD). It is closely related to aerosol composition. Black carbon (BC) containing aerosols yield AAE values near unity whereas Organic carbon (OC) aerosol particles are associated with values larger than 2. Even larger AAE values have been reported for desert dust aerosol particles. Knowledge of spectral AAOD is necessary for the calculation of direct radiative forcing effect of aerosols and for inferring aerosol composition. We have developed a satellitebased method of determining the spectral AAOD of absorbing aerosols. The technique uses multi-spectral measurements of upwelling radiation from scenes where absorbing aerosols lie above clouds as indicated by the UV Aerosol Index. For those conditions, the satellite measurement can be explained, using an approximations of Beer's Law (BL), as the upwelling reflectance at the cloud top attenuated by the absorption effects of the overlying aerosol layer. The upwelling reflectance at the cloud-top in an aerosol-free atmospheric column is mainly a function of cloud optical depth (COD). In the proposed method of AAE derivation, the first step is determining COD which is retrieved using a previously developed color-ratio based approach. In the second step, corrections for molecular scattering effects are applied to both the observed ad the calculated cloud reflectance terms, and the spectral AAOD is then derived by an inversion of the BL approximation. The proposed technique will be discussed in detail and application results making use of OMI multi-spectral measurements in the UV-Vis. will be presented.

  3. New analytical technique for carbon dioxide absorption solvents

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

    Pouryousefi, F.; Idem, R.O.

    2008-02-15

    The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO{sub 2}, water + MDEA + CO{sub 2}, and water + MEA + MDEA) used for carbon dioxide (CO{sub 2}) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO{sub 2} absorption at temperatures from 295 to 338 K. Experimental densities were modeled empirically, while the experimental refractive indices were modeled using well-established models from the known values of their pure-component densities and refractive indices. The density and Gladstone-Dale refractive indexmore » models were then used to obtain the compositions of unknown samples of the binary and ternary systems by simultaneous solution of the density and refractive index equations. The results from this technique have been compared with HPLC (high-performance liquid chromatography) results, while a third independent technique (acid-base titration) was used to verify the results. The results show that the systems' compositions obtained from the simple and easy-to-use refractive index/density technique were very comparable to the expensive and laborious HPLC/titration techniques, suggesting that the refractive index/density technique can be used to replace existing methods for analysis of fresh or nondegraded, CO{sub 2}-loaded, single and mixed alkanolamine solutions.« less

  4. [Occupational stress effects on work ability in chemistry workers].

    PubMed

    Yang, Huifang; Wang, Mianzhen; Wang, Zhiming; Lan, Yajia

    2004-03-01

    Investigating the status of work ability and occupational stress in 1030 chemistry workers at levels of chemical materials and explore their relationship and influence factors (481 workers of study group, 549 workers of control group). Work ability and occupational stress were measured with the work ability index (WAI) and occupational stress questionnaire (OSQ). The risk factors of work ability decline were evaluated. WAI and OSQ scores scores are significantly different between study group and control group (P < 0.01), and work ability correlated inversely with occupational stress (P < 0.01). The WAI scores are reducing with a higher of the OSQ. The work ability of chemistry-workers became lower with the increasing of age. Variables that influence work ability included the factors of disorder of musculoskeletal function (OR = 2.884), assessment of the current health (OR = 2.651), the diseases (OR = 2.498), emotion status (OR = 2.407), physical load (OR = 1.254) and lack of exercise (OR = 1.956). The stress levels and stress factors had affected work ability in chemistry-workers, and it was suggested that the findings could be helpful for the measures protecting and promoting of work ability on the health of workers.

  5. Plasmonic Waveguide Coupled Ring Cavity for a Non-Resonant Type Refractive Index Sensor.

    PubMed

    Kwon, Soon-Hong

    2017-11-03

    Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on the refractive index of the analyte, have been developed. However, the spectral linewidth of the resonance, which becomes the resolution limit, is considerably large in plasmonic cavities due to the large absorption loss of metals. Therefore, there is demand for a new type of plasmonic refractive index sensor that is not limited by the linewidth of the cavity. We propose a new type of plasmonic index sensors consisting of a channel waveguide and a ring cavity. Two emissions from the ring cavity in both directions of the waveguide couple with a reflection phase difference depending on the length of a closed right arm with a reflecting boundary. Therefore, the output power dramatically and sensitively changes as a function of the refractive index of the analyte filling the waveguide.

  6. Plasmonic Waveguide Coupled Ring Cavity for a Non-Resonant Type Refractive Index Sensor

    PubMed Central

    Kwon, Soon-Hong

    2017-01-01

    Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on the refractive index of the analyte, have been developed. However, the spectral linewidth of the resonance, which becomes the resolution limit, is considerably large in plasmonic cavities due to the large absorption loss of metals. Therefore, there is demand for a new type of plasmonic refractive index sensor that is not limited by the linewidth of the cavity. We propose a new type of plasmonic index sensors consisting of a channel waveguide and a ring cavity. Two emissions from the ring cavity in both directions of the waveguide couple with a reflection phase difference depending on the length of a closed right arm with a reflecting boundary. Therefore, the output power dramatically and sensitively changes as a function of the refractive index of the analyte filling the waveguide. PMID:29099740

  7. Light Absorption of Stratospheric Aerosols: Long-Term Trend and Contribution by Aircraft

    NASA Technical Reports Server (NTRS)

    Pueschel , R. F.; Gore, Waren J. Y. (Technical Monitor)

    1997-01-01

    Measurements of aerosol light-absorption coefficients are useful for studies of radiative transfer and heating rates. Ogren appears to have published the first light- absorption coefficients in the stratosphere in 1981, followed by Clarke in 1983 and Pueschel in 1992. Because most stratospheric soot appears to be due to aircraft operations, application of an aircraft soot aerosol emission index to projected fuel consumption suggests a threefold increase of soot loading and light absorption by 2025. Together, those four data sets indicate an increase in mid-visible light extinction at a rate of 6 % per year. This trend is similar to the increase per year of sulfuric acid aerosol and of commercial fleet size. The proportionality between stepped-up aircraft operations above the tropopause and increases in stratospheric soot and sulfuric acid aerosol implicate aircraft as a source of stratospheric pollution. Because the strongly light-absorbing soot and the predominantly light-scattering sulfuric acid aerosol increase at similar rates, however, the mid-visible stratospheric aerosol single scatter albedo is expected to remain constant and not approach a critical value of 0.98 at which stratospheric cooling could change to warming.

  8. [Occupational and non-occupational determinants of work ability].

    PubMed

    Makowiec-Dabrowska, Teresa; Koszada-Włodarczyk, Wiesława; Bortkiewicz, Alicja; Gadzicka, Elzbieta; Siedlecka, Jadwiga; Jóźwiak, Zbigniew; Pokorski, Janusz

    2008-01-01

    Measurements of the work ability subjective assessment, using the work ability index (WAI), are widely applied in the examination of workers. The measurement results suggest that the low level of work ability, which is determined by work-burden factors, health condition, and lifestyles of persons under study, can be a predictor of earlier retirement. The aim of the study was to find out whether WAI can be used in Polish conditions and to identify personal traits and/or job characteristics and conditions of its performance that generate the risk of low work ability. The cross-sectional study embraced 669 men and 536 women at the working age, representing different occupations and exposed to various factors. They self-assessed their work ability by completing a questionnaire that allows to determine WAI values. They also characterized their jobs in terms of physical burden, occupational stress, harmful and strenuous factors, work fatigue, chronic fatigue, and lifestyle. Based on the energy expenditure and health condition (number of diseases), the work burden was objectively defined. A model of multivariate logistic regression was used to assess the effect of the analyzed factors on the risk of low or moderate work ability. The level of work ability in the study group was lower than that observed in analogous occupational groups in other European countries. The results of the analysis indicate that job characterizing factors and workers' individual traits exert a stronger effect on the level of WAI components, which reflect a subjective assessment of work abilities, than factors concerning health conditions. Highly stressogenic work and low tolerance of work burden as well as personal traits (age, frequent alcohol consumption among men and non-occupational burdens among women) represented risk factors responsible for low or moderate VAI values. The measurement of work ability index is an indirect assessment of workers' physical state, and it slightly depends on

  9. Concentration measurement of NO using self-absorption spectroscopy of the γ band system in a pulsed corona discharge.

    PubMed

    Zhai, Xiaodong; Ding, Yanjun; Peng, Zhimin; Luo, Rui

    2012-07-10

    Nitric oxide (NO) concentrations were measured using the γ band system spectrum based on the strong self-absorption effect of NO in pulsed corona discharges. The radiative transitional intensities of the NO γ band were simulated based on the theory of molecular spectroscopy. The intensities of some bands, especially γ(0,0) and γ(1,0), are weakened by the self-absorption. The correlations between the spectral self-absorption intensities and NO concentration were validated using a modified Beer-Lambert law with a combined factor K relating the branching ratio and the NO concentration, and a nonlinear index α that is applicable to the broadband system. Optical emissive spectra in pulsed corona discharges in NO and N2/He mixtures were used to evaluate the two parameters for various conditions. Good agreement between the experimental and theoretical results verifies the self-absorption behavior seen in the UV spectra of the NO γ bands.

  10. Synthesis and evaluation of changes induced by solvent and substituent in electronic absorption spectra of some azo disperse dyes

    NASA Astrophysics Data System (ADS)

    Mohammadi, Asadollah; Yazdanbakhsh, Mohammad Reza; Farahnak, Lahya

    2012-04-01

    Five azo disperse dyes were prepared by diazotizing 4'-aminoacetophenone and p-anisidine and coupling with varies N-alkylated aromatic amines. Characterization of the dyes was carried out by using UV-vis, FTIR and 1H NMR spectroscopic techniques. The electronic absorption spectra of dyes are determined at room temperature in fifteen solvents with different polarities. The solvent dependent maximum absorption band shifts, were investigated using dielectric constant (ɛ), refractive index (n) and Kamlet-Taft polarity parameters (hydrogen bond donating ability (α), hydrogen bond accepting ability (β) and dipolarity/polarizability polarity scale (π*)). Acceptable agreement was found between the maximum absorption band of dyes and solvent polarity parameters especially with π*. The effect of substituents of coupler and/or diazo component on the color of dyes was investigated. The effects of acid and base on the visible absorption maxima of the dyes are also reported.

  11. Two-dimensional interferometric characterization of laser-induced refractive index profiles in bulk Topas polymer

    NASA Astrophysics Data System (ADS)

    Hessler, Steffen; Rosenberger, Manuel; Schmauss, Bernhard; Hellmann, Ralf

    2018-01-01

    In this paper we precisely determine laser-induced refractive index profiles created in cyclic olefin copolymer Topas 6017 employing a sophisticated phase shifting Mach-Zehnder interferometry approach. Beyond the usual one-dimensional modification depth measurement we highlight that for straight waveguide structures also a two-dimensional refractive index distribution can be directly obtained providing full information of a waveguide's exact cross section and its gradient refractive index contrast. Deployed as direct data input in optical waveguide simulation, the evaluated 2D refractive index profiles permit a detailed calculation of the waveguides' actual mode profiles. Furthermore, conventional one-dimensional interferometric measurements for refractive index depth profiles with varying total imposed laser fluence of a 248 nm KrF excimer laser are included to investigate the effect on refractive index modification depth. Maximum surface refractive index increase turns out to attain up to 1.86 ·10-3 enabling laser-written optical waveguide channels. Additionally, a comprehensive optical material characterization in terms of dispersion, thermo-optic coefficient and absorption measurement of unmodified and UV-modified Topas 6017 is carried out.

  12. Gamma–Gamma Absorption in the γ-ray Binary System PSR B1259-63/LS 2883

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

    Sushch, Iurii; Van Soelen, Brian, E-mail: iurii.sushch@desy.de, E-mail: vansoelenb@ufs.ac.za

    2017-03-10

    The observed TeV light curve from the γ -ray binary PSR B1259-63/LS 2883 shows a decrease in the flux at periastron that has not been fully explained by emission mechanisms alone. This observed decrease can, however, be explained by γγ absorption due to the stellar and disk photons. We calculate the γγ absorption in PSR B1259-63/LS 2883 taking into account photons from both the circumstellar disk and star, assuming that the γ -rays originate at the position of the pulsar. The γγ absorption due to the circumstellar disk photons produces a ≈14% decrease in the flux, and there is amore » total decrease of ≈52% (>1 TeV) within a few days before periastron, accompanied by a hardening of the γ -ray photon index. While the γγ absorption alone is not sufficient to explain the full complexity of the H.E.S.S. γ -ray light curve, it results in a significant decrease in the predicted flux, which is coincident with the observed decrease. In addition, we have calculated an upper limit on the γγ absorption, assuming that the emission is produced at the apex of the bow shock. Future observations with CTA during the 2021 periastron passage may be able to confine the location of the emission based on the degree of γγ absorption, as well as measure the hardening of the spectrum around periastron.« less

  13. Simultaneous Chemical and Refractive Index Sensing in the 1-2.5 μm Near-Infrared Wavelength Range on Nanoporous Gold Disks.

    PubMed

    Shih, Wei-Chuan; Santos, Greggy M; Zhao, Fusheng; Zenasni, Oussama; Arnob, Md Masud Parvez

    2016-07-13

    Near-infrared (NIR) absorption spectroscopy provides molecular and chemical information based on overtones and combination bands of the fundamental vibrational modes in the infrared wavelengths. However, the sensitivity of NIR absorption measurement is limited by the generally weak absorption and the relatively poor detector performance compared to other wavelength ranges. To overcome these barriers, we have developed a novel technique to simultaneously obtain chemical and refractive index sensing in 1-2.5 μm NIR wavelength range on nanoporous gold (NPG) disks, which feature high-density plasmonic hot-spots of localized electric field enhancement. For the first time, surface-enhanced near-infrared absorption (SENIRA) spectroscopy has been demonstrated for high sensitivity chemical detection. With a self-assembled monolayer (SAM) of octadecanethiol (ODT), an enhancement factor (EF) of up to ∼10(4) has been demonstrated for the first C-H combination band at 2400 nm using NPG disk with 600 nm diameter. Together with localized surface plasmon resonance (LSPR) extinction spectroscopy, simultaneous sensing of sample refractive index has been achieved for the first time. The performance of this technique has been evaluated using various hydrocarbon compounds and crude oil samples.

  14. Aprotic solvents effect on the UV-visible absorption spectra of bixin

    NASA Astrophysics Data System (ADS)

    Rahmalia, Winda; Fabre, Jean-François; Usman, Thamrin; Mouloungui, Zéphirin

    2014-10-01

    We describe here the effects of aprotic solvents on the spectroscopic characteristics of bixin. Bixin was dissolved in dimethyl sulfoxide, acetone, dichloromethane, ethyl acetate, chloroform, dimethyl carbonate, cyclohexane and hexane, separately, and its spectra in the resulting solutions were determined by UV-visible spectrophotometry at normal pressure and room temperature. We analyzed the effect of aprotic solvents on λmax according to Onsager cavity model and Hansen theory, and determined the approximate absorption coefficient with the Beer-Lambert law. We found that the UV-visible absorption spectra of bixin were found to be solvent dependent. The S0 → S2 transition energy of bixin in solution was dependent principally on the refractive index of the solvents and the bixin-solvent dispersion interaction. There was a small influence of the solvents dielectric constant, permanent dipole interaction and hydrogen bonding occurred between bixin and solvents. The absorbance of bixin in various solvents, with the exception of hexane, increased linearly with concentration.

  15. Optical Absorption in Liquid Semiconductors

    NASA Astrophysics Data System (ADS)

    Bell, Florian Gene

    An infrared absorption cell has been developed which is suitable for high temperature liquids which have absorptions in the range .1-10('3) cm('-1). The cell is constructed by clamping a gasket between two flat optical windows. This unique design allows the use of any optical windows chemically compatible with the liquid. The long -wavelength limit of the measurements is therefore limited only by the choice of the optical windows. The thickness of the cell can easily be set during assembly, and can be varied from 50 (mu)m to .5 cm. Measurements of the optical absorption edge were performed on the liquid alloy Se(,1-x)Tl(,x) for x = 0, .001, .002, .003, .005, .007, and .009, from the melting point up to 475(DEGREES)C. The absorption was found to be exponential in the photon energy over the experimental range from 0.3 eV to 1.2 eV. The absorption increased linearly with concentration according to the empirical relation (alpha)(,T)(h(nu)) = (alpha)(,1) + (alpha)(,2)x, and the absorption (alpha)(,1) was interpreted as the absorption in the absence of T1. (alpha)(,1) also agreed with the measured absorption in 100% Se at corresponding temperatures and energies. The excess absorption defined by (DELTA)(alpha) = (alpha)(,T)(h(nu))-(alpha)(,1) was interpreted as the absorption associated with Tl and was found to be thermally activated with an activation energy E(,t) = 0.5 eV. The exponential edge is explained as absorption on atoms immersed in strong electric fields surrounding ions. The strong fields give rise to an absorption tail similar to the Franz-Keldysh effect. A simple calculation is performed which is based on the Dow-Redfield theory of absorption in an electric field with excitonic effects included. The excess absorption at low photon energies is proportional to the square of the concentration of ions, which are proposed to exist in the liquid according to the relation C(,i) (PROPORTIONAL) x(' 1/2)(.)e('-E)t('/kT), which is the origin of the thermal activation

  16. The great contribution: Index Medicus, Index-Catalogue, and IndexCat

    PubMed Central

    Greenberg, Stephen J.; Gallagher, Patricia E.

    2009-01-01

    Objective: The systematic indexing of medical literature by the Library of the Surgeon-General's Office (now the National Library of Medicine) has been called “America's greatest contribution to medical knowledge.” In the 1870s, the library launched two indexes: the Index Medicus and the Index-Catalogue of the Library of the Surgeon-General's Office. Index Medicus is better remembered today as the forerunner of MEDLINE, but Index Medicus began as the junior partner of what the library saw as its major publication, the Index-Catalogue. However, the Index-Catalogue had been largely overlooked by many medical librarians until 2004, when the National Library of Medicine released IndexCat, the online version of Index-Catalogue. Access to this huge amount of material raised new questions: What was the coverage of the Index-Catalogue? How did it compare and overlap with the Index Medicus? Method: Over 1,000 randomly generated Index Medicus citations were cross-referenced in IndexCat. Results: Inclusion, form, content, authority control, and subject headings were evaluated, revealing that the relationship between the two publications was neither simple nor static through time. In addition, the authors found interesting anomalies that shed light on how medical literature was selected and indexed in “America's greatest contribution to medical knowledge.” PMID:19404501

  17. Negative refraction with low absorption using Raman transitions with magnetoelectric coupling

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

    Sikes, D. E.; Yavuz, D. D.

    2010-07-15

    We suggest a scheme for obtaining negative refraction that does not require the simultaneous presence of an electric-dipole and a magnetic-dipole transition near the same transition frequency. The key idea of the scheme is to obtain a strong electric response by using far-off-resonant Raman transitions. We propose to use a pair of electric-dipole Raman transitions and utilize magneto-electric cross coupling to achieve a negative index of refraction without requiring negative permeability. The interference of the two Raman transitions allows tunable negative refraction with low absorption.

  18. Real part of refractive index measurement approach for absorbing liquid.

    PubMed

    Liu, Hao; Ye, Junwei; Yang, Kecheng; Xia, Min; Guo, Wenping; Li, Wei

    2015-07-01

    An algorithm based on use of a reflected refractometer to measure the real part of the refractive index (RI) for an absorbing liquid is presented. The absorption of liquid will blur the division between bright and dark regions on a Fresnel reflective curve. However, the reflective ratio at some incident angles that are less than the critical angle have little sensitivity to absorbability. Unlike common methods that extract RI from reflectivity in critical angle vicinity, the presented method acquires the real RI from reflective ratio at a subcritical angle. Supported by the theoretical analysis and experimental results on a reflected refractometer, we have achieved accuracy better than 3×10(-4) RIU on ink samples with absorption coefficient around 300  cm(-1). Additional tests on Alizarin yellow GG solutions prove that the subcritical algorithm is feasible and of high accuracy.

  19. High sensitivity of Indian summer monsoon to Middle East dust absorptive properties.

    PubMed

    Jin, Qinjian; Yang, Zong-Liang; Wei, Jiangfeng

    2016-07-28

    The absorptive properties of dust aerosols largely determine the magnitude of their radiative impacts on the climate system. Currently, climate models use globally constant values of dust imaginary refractive index (IRI), a parameter describing the dust absorption efficiency of solar radiation, although it is highly variable. Here we show with model experiments that the dust-induced Indian summer monsoon (ISM) rainfall differences (with dust minus without dust) change from -9% to 23% of long-term climatology as the dust IRI is changed from zero to the highest values used in the current literature. A comparison of the model results with surface observations, satellite retrievals, and reanalysis data sets indicates that the dust IRI values used in most current climate models are too low, tending to significantly underestimate dust radiative impacts on the ISM system. This study highlights the necessity for developing a parameterization of dust IRI for climate studies.

  20. Effect of Oral Lipid Matrix Supplement on Fat Absorption in Cystic Fibrosis: A Randomized Placebo-Controlled Trial.

    PubMed

    Stallings, Virginia A; Schall, Joan I; Maqbool, Asim; Mascarenhas, Maria R; Alshaikh, Belal N; Dougherty, Kelly A; Hommel, Kevin; Ryan, Jamie; Elci, Okan U; Shaw, Walter A

    2016-12-01

    Pancreatic enzyme therapy does not normalize dietary fat absorption in patients with cystic fibrosis and pancreatic insufficiency. Efficacy of LYM-X-SORB (LXS), an easily absorbable lipid matrix that enhances fat absorption, was evaluated in a 12-month randomized, double-blinded, placebo-controlled trial with plasma fatty acids (FA) and coefficient of fat absorption (CFA) outcomes. A total of 110 subjects (age 10.4 ± 3.0 years) were randomized. Total FA increased with LXS at 3 and 12 months (+1.58, +1.14 mmol/L) and not with placebo (P = 0.046). With LXS, linoleic acid (LA) increased at 3 and 12 months (+298, +175 nmol/mL, P ≤ 0.046), with a 6% increase in CFA (P < 0.01). LA increase was significant in LXS versus placebo (445 vs 42 nmol/mL, P = 0.038). Increased FA and LA predicted increased body mass index Z scores. In summary, the LXS treatment improved dietary fat absorption compared with placebo as indicated by plasma FA and LA and was associated with better growth status.

  1. Composite Spectra of Broad Absorption Line Quasars in SDSS-III BOSS

    NASA Astrophysics Data System (ADS)

    Herbst, Hanna; Hamann, Fred; Paris, Isabelle; Capellupo, Daniel M.

    2017-01-01

    We present preliminary results from a study of broad absorption line (BAL) quasars in the SDSS-III BOSS survey. We’re particularly interested in BALs because they arise from quasar outflows, which may be a source of feedback to the host galaxy. We analyze median composite spectra for BOSS QSOs in the redshift range 2.1 to 3.4 sorted by the strength of the BAL absorption troughs, parameterized by the Balnicity Index (BI), to study trends in the emission and absorption properties of BAL quasars. The wavelength coverage and high number of quasars observed in the BOSS survey allow us to examine BALs in the Lyman forest. Our main preliminary results when sorting the quasars by BI are 1) doublet absorption lines such as P V 1128A show a 1:1 ratio across all BI, indicating large column densities at all BI. This suggests that weaker BAL troughs result from smaller covering fractions rather than lower column densities. 2) The He II emission line, which is a measure of the far-UV/near-UV hardness of the ionizing continuum, is weaker in the larger BI composite spectra, indicating a far-UV spectral softening correlated with BI. This is consistent with the radiatively-driven BAL outflows being helped by intrinsically weaker ionizing continuum shapes (e.g., Baskin, Laor, and Hamann 2013). We also find a trend for slightly redder continuum slopes in the larger BI composite spectra, suggesting that the slope differences in the near-UV are also intrinsic.

  2. On the pattern of WAIS retreat in eastern Ross Sea based on a regional synthesis of new geophysical and geological data acquired during NBP1502

    NASA Astrophysics Data System (ADS)

    McGlannan, A. J.; Bart, P. J.; Anderson, J. B.

    2016-02-01

    New multibeam and seismic data acquired during NBP1502 reveal that a series of backstepping grounding zone wedges (GZWs) were constructed on the middle shelf as the West Antarctic Ice Sheet (WAIS) retreated from the Whales Deep paleo-ice stream trough. The geomorphological information provided by these geophysical data were used to acquire a regional grid of jumbo-piston and kasten cores. Here, we present our regional synthesis of the new geophysical and geological data. The distributions of upcore transitions from diamict to sub-ice-shelf facies on the outer-most shelf demonstrate that as the grounded ice retreated in four discrete backsteps, the calving front remained in the vicinity of the shelf edge, approximately 50 kilometers to the north. In contrast, the upcore transition at the fourth backstep shows GZW diamict directly overlain by open-marine facies. We interpret this to indicate that a major retreat of both grounded and floating ice was associated with the termination of the middle-shelf grounding event. The minimum retreat distance was greater than 100 kilometers.

  3. Gastrointestinal citrate absorption in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

  4. The OMI Aerosol Absorption Product: An A-train application

    NASA Astrophysics Data System (ADS)

    Torres, O.; Jethva, H. T.; Ahn, C.

    2017-12-01

    Because of the uniquely large sensitivity of satellite-measured near-UV radiances to absorption by desert dust, carbonaceous and volcanic ash aerosols, observations by a variety of UV-capable sensors have been routinely used over the last forty years in both qualitative and quantitative applications for estimating the absorption properties of these aerosol types. In this presentation we will discuss a multi-sensor application involving observations from A-train sensors OMI, AIRS and CALIOP for the creation of a 13-year record of aerosol optical depth (AOD) and single scattering albedo (SSA). Determination of aerosol type, in terms of particle size distribution and refractive index, is an important algorithmic step that requires using external information. AIRS CO measurements are used as carbonaceous aerosols tracer to differentiate this aerosol type from desert dust. On the other hand, the height of the absorbing aerosol layer, an important parameter in UV aerosol retrievals, is prescribed using a CALIOP-based climatology. The combined use of these observations in the developments of the OMI long-term AOD/SSA record will be discussed along with an evaluation of retrieval results using independent observations.

  5. Optical absorption of zigzag single walled boron nitride nanotubes

    NASA Astrophysics Data System (ADS)

    Moradian, Rostam; Chegel, Raad; Behzad, Somayeh

    2010-11-01

    In a realistic three-dimensional model, optical matrix element and linear optical absorption of zigzag single walled boron nitride nanotubes (BNNTs) in the tight binding approximation are studied. In terms of absolute value of dipole matrix elements of the first three direct transitions at kz=0, we divided the zigzag BNNTs into three groups and investigated their optical absorption spectrum in energy ranges E<5, 77.5 eV. We found that in lower energies, E<5 eV, all groups show different behaviors while in the higher energies, 77.5 eV, their behaviors depend on their even or odd nanotube index. We also found that in the energy range 7

  6. Subgap Absorption in Conjugated Polymers

    DOE R&D Accomplishments Database

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  7. Absorption of acoustic waves by sunspots. II - Resonance absorption in axisymmetric fibril models

    NASA Technical Reports Server (NTRS)

    Rosenthal, C. S.

    1992-01-01

    Analytical calculations of acoustic waves scattered by sunspots which concentrate on the absorption at the magnetohydrodynamic Alfven resonance are extended to the case of a flux-tube embedded in a uniform atmosphere. The model is based on a flux-tubes of varying radius that are highly structured, translationally invariant, and axisymmetric. The absorbed fractional energy is determined for different flux-densities and subphotospheric locations with attention given to the effects of twist. When the flux is highly concentrated into annuli efficient absorption is possible even when the mean magnetic flux density is low. The model demonstrates low absorption at low azimuthal orders even in the presence of twist which generally increases the range of wave numbers over which efficient absorption can occur. Resonance absorption is concluded to be an efficient mechanism in monolithic sunspots, fibril sunspots, and plage fields.

  8. Petawatt laser absorption bounded

    PubMed Central

    Levy, Matthew C.; Wilks, Scott C.; Tabak, Max; Libby, Stephen B.; Baring, Matthew G.

    2014-01-01

    The interaction of petawatt (1015 W) lasers with solid matter forms the basis for advanced scientific applications such as table-top particle accelerators, ultrafast imaging systems and laser fusion. Key metrics for these applications relate to absorption, yet conditions in this regime are so nonlinear that it is often impossible to know the fraction of absorbed light f, and even the range of f is unknown. Here using a relativistic Rankine-Hugoniot-like analysis, we show for the first time that f exhibits a theoretical maximum and minimum. These bounds constrain nonlinear absorption mechanisms across the petawatt regime, forbidding high absorption values at low laser power and low absorption values at high laser power. For applications needing to circumvent the absorption bounds, these results will accelerate a shift from solid targets, towards structured and multilayer targets, and lead the development of new materials. PMID:24938656

  9. [The study of CO2 cavity enhanced absorption and highly sensitive absorption spectroscopy].

    PubMed

    Pei, Shi-Xin; Gao, Xiao-Ming; Cui, Fen-Ping; Huang, Wei; Shao, Jie; Fan, Hong; Zhang, Wei-Jun

    2005-12-01

    Cavity enhanced absorption spectroscopy (CEAS) is a new spectral technology that is based on the cavity ring down absorption spectroscopy. In the present paper, a DFB encapsulation narrow line width tunable diode laser (TDL) was used as the light source. At the center output, the TDL radiation wavelength was 1.573 microm, and an optical cavity, which consisted of two high reflectivity mirrors (near 1.573 microm, the mirror reflectivity was about 0.994%), was used as a sample cell. A wavemeter was used to record the accurate frequency of the laser radiation. In the experiment, the method of scanning the optical cavity to change the cavity mode was used, when the laser frequency was coincident with one of the cavity mode; the laser radiation was coupled into the optical cavity and the detector could receive the light signals that escaped the optical cavity. As a result, the absorption spectrum of carbon dioxide weak absorption at low pressure was obtained with an absorption intensity of 1.816 x 10(-23) cm(-1) x (molecule x cm(-2)(-1) in a sample cell with a length of only 33.5 cm. An absorption sensitivity of about 3.62 x 10(-7) cm(-1) has been achieved. The experiment result indicated that the cavity enhanced absorption spectroscopy has the advantage of high sensivity, simple experimental setup, and easy operation.

  10. Retrieval of the complex refractive index of aerosol droplets from optical tweezers measurements.

    PubMed

    Miles, Rachael E H; Walker, Jim S; Burnham, Daniel R; Reid, Jonathan P

    2012-03-07

    The cavity enhanced Raman scattering spectrum recorded from an aerosol droplet provides a unique fingerprint of droplet radius and refractive index, assuming that the droplet is homogeneous in composition. Aerosol optical tweezers are used in this study to capture a single droplet and a Raman fingerprint is recorded using the trapping laser as the source for the Raman excitation. We report here the retrieval of the real part of the refractive index with an uncertainty of ± 0.0012 (better than ± 0.11%), simultaneously measuring the size of the micrometre sized liquid droplet with a precision of better than 1 nm (< ± 0.05% error). In addition, the equilibrium size of the droplet is shown to depend on the laser irradiance due to optical absorption, which elevates the droplet temperature above that of the ambient gas phase. Modulation of the illuminating laser power leads to a modulation in droplet size as the temperature elevation is altered. By measuring induced size changes of <1 nm, we show that the imaginary part of the refractive index can be retrieved even when less than 10 × 10(-9) with an accuracy of better than ± 0.5 × 10(-9). The combination of these measurements allows the complex refractive index of a droplet to be retrieved with high accuracy, with the possibility of making extremely sensitive optical absorption measurements on aerosol samples and the testing of frequently used mixing rules for treating aerosol optical properties. More generally, this method provides an extremely sensitive approach for measuring refractive indices, particularly under solute supersaturation conditions that cannot be accessed by simple bulk-phase measurements.

  11. Therapeutic alliance in early schizophrenia spectrum disorders: a cross-sectional study.

    PubMed

    Johansen, Ragnhild; Iversen, Valentina C; Melle, Ingrid; Hestad, Knut A

    2013-05-09

    The therapeutic alliance is related to better course and outcome of treatment in schizophrenia. This study explores predictors and characteristics of the therapeutic alliance in recent-onset schizophrenia spectrum disorders including the agreement between patient and therapist alliance ratings. Forty-two patients were assessed with demographic, neurocognitive, and clinical measures including the Positive and Negative Syndrome Scale (PANSS). The therapeutic alliance was measured with the Working Alliance Inventory - Short Form (WAI-S). Patient WAI-S total scores were predicted by age and PANSS excitative symptoms. Therapist WAI-S total scores were predicted by PANSS insight. Patient and therapist WAI-S total scores were moderately associated. Neurocognition was not associated with working alliance. Working alliance is associated with specific demographic and symptom characteristics in patients with recent-onset schizophrenia spectrum disorders. There is moderate agreement between patients and therapists on the total quality of their working alliance. Findings highlight aspects that may increase therapists' specificity in the use of alliance-enhancing strategies.

  12. Dynamics of short pulses and phase matched second harmonic generation in negative index materials.

    PubMed

    Scalora, Michael; D'Aguanno, Giuseppe; Bloemer, Mark; Centini, Marco; de Ceglia, Domenico; Mattiucci, Nadia; Kivshar, Yuri S

    2006-05-29

    We study pulsed second harmonic generation in metamaterials under conditions of significant absorption. Tuning the pump in the negative index range, a second harmonic signal is generated in the positive index region, such that the respective indices of refraction have the same magnitudes but opposite signs. This insures that a forward-propagating pump is exactly phase matched to the backward-propagating second harmonic signal. Using peak intensities of ~500 MW/cm(2), assuming chi((2))~80pm/V, we predict conversion efficiencies of 12% and 0.2% for attenuation lengths of 50 and 5microm, respectively.

  13. Wideband acoustic immittance for assessing middle ear functioning for preterm neonates in the neonatal intensive care unit.

    PubMed

    Gouws, Nandel; Swanepoel, De Wet; De Jager, Leigh Biagio

    2017-06-28

    The primary aim of newborn hearing screening is to detect permanent hearing loss. Because otoacoustic emissions (OAEs) and automated auditory brainstem response (AABR) are sensitive to hearing loss, they are often used as screening tools. On the other hand, false-positive results are most often because of transient outer- and middle ear conditions. Wideband acoustic immittance (WAI), which includes physical measures known as reflectance and absorbance, has shown potential for accurate assessment of middle ear function in young infants. The main objective of this study was to determine the feasibility of WAI as a diagnostic tool for assessing middle ear functioning in preterm neonates in the neonatal intensive care unit (NICU) designed for premature and ill neonates. A further objective was to indicate the difference between the reflectance values of tones and click stimuli. Fifty-six at-risk neonates (30 male and 26 female), with a mean age at testing of 35.6 weeks (range: 32-37 weeks) and a standard deviation of 1.6 from three private hospitals, who passed both the distortion product otoacoustic emission (DPOAE) and AABR tests, were evaluated prior to discharge from the NICU. Neonates who presented with abnormal DPOAE and AABR results were excluded from the study. WAI was measured by using chirp and tone stimuli. In addition to reflectance, the reflectance area index (RAI) values were calculated. Both tone and chirp stimuli indicated high-power reflectance values below a frequency of 1.5 kHz. Median reflectance reached a minimum of 0.67 at 1 kHz - 2 kHz but increased to 0.7 below 1 kHz and 0.72 above 2 kHz for the tone stimuli. For chirp stimuli, the median reflectance reached a minimum of 0.51 at 1 kHz - 2 kHz but increased to 0.68 below 1 kHz and decreased to 0.5 above 2 kHz. A comparison between the present study and previous studies on WAI indicated a substantial variability across all frequency ranges. These WAI measurements conducted on at-risk preterm NICU

  14. The HSE indicator tool, psychological distress and work ability.

    PubMed

    Guidi, S; Bagnara, S; Fichera, G P

    2012-04-01

    The Health and Safety Executive (HSE) indicator tool is one of the most commonly used tools for assessing the risk of work-related stress. Few studies, however, have investigated whether and how its scales are related to psychological distress or other work-related health outcomes. To investigate the relationship between the HSE indicator tool, psychological distress, as measured by the General Health Questionnaire (GHQ)-12, and work ability, assessed by the Work Ability Index (WAI). All the employees of a mid-sized bank in Italy were asked to fill in an anonymous cross-sectional questionnaire. The questionnaire was structured in four sections: the first one comprised socio-demographic questions and the other three corresponded, respectively, to the Italian translations of the GHQ-12, the HSE and the WAI questionnaires. Four hundred and thirteen employees completed the questionnaire. The response rate was 99%. Controlling for age and gender, the indicator subscales were negatively associated with the adopted measures of psychological distress and work ability. The GHQ score was also highly correlated with the WAI score and able to explain ≈ 47% of its variance. The only subscale that was still significantly associated with the WAI after removing the effect of psychological distress was 'control'. The study presents new evidence for the validity of the HSE indicator tool to estimate the risk of work-related stress and suggests that most but not all the effects of psychosocial conditions on work ability might be mediated by the level of psychological distress induced by these conditions.

  15. Influence of synchrotron self-absorption on 21-cm experiments

    NASA Astrophysics Data System (ADS)

    Zheng, Qian; Wu, Xiang-Ping; Gu, Jun-Hua; Wang, Jingying; Xu, Haiguang

    2012-08-01

    The presence of spectral curvature resulting from the synchrotron self-absorption of extragalactic radio sources could break down the spectral smoothness feature. This leads to the premise that the bright radio foreground can be successfully removed in 21-cm experiments that search for the epoch of reionization (EoR). We present a quantitative estimate of the effect of the spectral curvature resulting from the synchrotron self-absorption of extragalactic radio sources on the measurement of the angular power spectrum of the low-frequency sky. We incorporate a phenomenological model, which is characterized by the fraction (f) of radio sources with turnover frequencies in the range of 100-1000 MHz and by a broken power law for the spectral transition around the turnover frequencies νm, into simulated radio sources over a small sky area of 10° × 10°. We compare statistically the changes in their residual maps with and without the inclusion of the synchrotron self-absorption of extragalactic radio sources after the bright sources of S150 MHz ≥100 mJy are excised. Furthermore, the best-fitting polynomials in the frequency domain on each pixel are subtracted. It has been shown that the effect of synchrotron self-absorption on the detection of the EoR depends sensitively on the spectral profiles of the radio sources around the turnover frequencies νm. A hard transition model, described by the broken power law with the turnover of spectral index at νm, would leave pronounced imprints on the residual background and would therefore cause serious confusion with the cosmic EoR signal. However, the spectral signatures on the angular power spectrum of the extragalactic foreground, generated by a soft transition model in which the rising and falling power laws of the spectral distribution around νm are connected through a smooth transition spanning ≥200 MHz in a characteristic width, can be fitted and consequently subtracted by the use of polynomials to an acceptable

  16. Thermo-optic coefficient and nonlinear refractive index of silicon oxynitride waveguides

    NASA Astrophysics Data System (ADS)

    Trenti, A.; Borghi, M.; Biasi, S.; Ghulinyan, M.; Ramiro-Manzano, F.; Pucker, G.; Pavesi, L.

    2018-02-01

    Integrated waveguiding devices based on silicon oxynitride (SiON) are appealing for their relatively high refractive index contrast and broadband transparency. The lack of two photon absorption at telecom wavelengths and the possibility to fabricate low loss waveguides make SiON an ideal platform for on-chip nonlinear optics and for the realization of reconfigurable integrated quantum lightwave circuits. Despite this, very few studies on its linear and nonlinear optical properties have been reported so far. In this work, we measured the thermo-optic coefficient dn/dT and the nonlinear refractive index n2 of relatively high (n ˜ 1.83 at a wavelength of 1.55 μm) refractive index SiON by using racetrack resonators. These parameters have been determined to be d/n d T =(1.84 ±0.17 ) × 10-5 K-1 and n2 = (7 ± 1) × 10-16 cm2W-1.

  17. Ellipsometric analysis and optical absorption characterization of gallium phosphide nanoparticulate thin film

    NASA Astrophysics Data System (ADS)

    Zhang, Qi-Xian; Wei, Wen-Sheng; Ruan, Fang-Ping

    2011-04-01

    Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO2 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells.

  18. Metal powder absorptivity: Modeling and experiment

    DOE PAGES

    Boley, C. D.; Mitchell, S. C.; Rubenchik, A. M.; ...

    2016-08-10

    Here, we present results of numerical modeling and direct calorimetric measurements of the powder absorptivity for a number of metals. The modeling results generally correlate well with experiment. We show that the powder absorptivity is determined, to a great extent, by the absorptivity of a flat surface at normal incidence. Our results allow the prediction of the powder absorptivity from normal flat-surface absorptivity measurements.

  19. Metal powder absorptivity: Modeling and experiment

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

    Boley, C. D.; Mitchell, S. C.; Rubenchik, A. M.

    Here, we present results of numerical modeling and direct calorimetric measurements of the powder absorptivity for a number of metals. The modeling results generally correlate well with experiment. We show that the powder absorptivity is determined, to a great extent, by the absorptivity of a flat surface at normal incidence. Our results allow the prediction of the powder absorptivity from normal flat-surface absorptivity measurements.

  20. Time-dependent oral absorption models

    NASA Technical Reports Server (NTRS)

    Higaki, K.; Yamashita, S.; Amidon, G. L.

    2001-01-01

    The plasma concentration-time profiles following oral administration of drugs are often irregular and cannot be interpreted easily with conventional models based on first- or zero-order absorption kinetics and lag time. Six new models were developed using a time-dependent absorption rate coefficient, ka(t), wherein the time dependency was varied to account for the dynamic processes such as changes in fluid absorption or secretion, in absorption surface area, and in motility with time, in the gastrointestinal tract. In the present study, the plasma concentration profiles of propranolol obtained in human subjects following oral dosing were analyzed using the newly derived models based on mass balance and compared with the conventional models. Nonlinear regression analysis indicated that the conventional compartment model including lag time (CLAG model) could not predict the rapid initial increase in plasma concentration after dosing and the predicted Cmax values were much lower than that observed. On the other hand, all models with the time-dependent absorption rate coefficient, ka(t), were superior to the CLAG model in predicting plasma concentration profiles. Based on Akaike's Information Criterion (AIC), the fluid absorption model without lag time (FA model) exhibited the best overall fit to the data. The two-phase model including lag time, TPLAG model was also found to be a good model judging from the values of sum of squares. This model also described the irregular profiles of plasma concentration with time and frequently predicted Cmax values satisfactorily. A comparison of the absorption rate profiles also suggested that the TPLAG model is better at prediction of irregular absorption kinetics than the FA model. In conclusion, the incorporation of a time-dependent absorption rate coefficient ka(t) allows the prediction of nonlinear absorption characteristics in a more reliable manner.

  1. Intestinal Water Absorption Varies with Expected Dietary Water Load among Bats but Does Not Drive Paracellular Nutrient Absorption.

    PubMed

    Price, Edwin R; Brun, Antonio; Gontero-Fourcade, Manuel; Fernández-Marinone, Guido; Cruz-Neto, Ariovaldo P; Karasov, William H; Caviedes-Vidal, Enrique

    2015-01-01

    Rapid absorption and elimination of dietary water should be particularly important to flying species and were predicted to vary with the water content of the natural diet. Additionally, high water absorption capacity was predicted to be associated with high paracellular nutrient absorption due to solvent drag. We compared the water absorption rates of sanguivorous, nectarivorous, frugivorous, and insectivorous bats in intestinal luminal perfusions. High water absorption rates were associated with high expected dietary water load but were not highly correlated with previously measured rates of (paracellular) arabinose clearance. In conjunction with these tests, we measured water absorption and the paracellular absorption of nutrients in the intestine and stomach of vampire bats using luminal perfusions to test the hypothesis that the unique elongated vampire stomach is a critical site of water absorption. Vampire bats' gastric water absorption was high compared to mice but not compared to their intestines. We therefore conclude that (1) dietary water content has influenced the evolution of intestinal water absorption capacity in bats, (2) solvent drag is not the only driver of paracellular nutrient absorption, and (3) the vampire stomach is a capable but not critical location for water absorption.

  2. Gender and age do not influence the ability to work.

    PubMed

    Padula, Rosimeire Simprini; da Silva Valente, Luciana do Socorro; de Moraes, Mônica Vasconcelos; Chiavegato, Luciana Dias; Cabral, Cristina Maria Nunes

    2012-01-01

    Work capacity is related to physical, environmental and psychosocial factors and is influenced by individual characteristics and occupations. The aim of this study was to evaluated the relationship between work capacity, gender and age. 360 people employed at an institution of higher education of both genders and similar age were asked to participate in this study. The ability to work was analyzed using Work Ability Index (WAI). Descriptive statistical, Pearson correlations and ANOVA test was applied. Of these, 197 workers who participated in the study completed and returned the questionnaire. The results show there weren't any significant differences between work ability in relation to gender and age, but we observed an increase variability of responses for WAI score in older workers. No significant differences in the perception of the ability of work between men and women..

  3. Determining CDOM Absorption Spectra in Diverse Coastal Environments Using a Multiple Pathlength, Liquid Core Waveguide System. Measuring the Absorption of CDOM in the Field Using a Multiple Pathlength Liquid Waveguide System

    NASA Technical Reports Server (NTRS)

    Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

    2000-01-01

    We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, a(sub CDOM), and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values (r > 0.99) and showed a linear response across all four pathlengths. Values of a(sub CDOM) measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of a(sub CDOM) for MPLCW measurements was 0.002 - 231.5/m. At low CDOM concentrations (a(sub 370) < 0.1/m) spectrophotometric a(sub CDOM) were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples. The maximum deviation in replicate MPLCW spectra was less than 0.001 absorbance units. The portability, sampling, and optical characteristics of a MPLCW system provide significant enhancements for routine CDOM absorption measurements in a broad range of natural waters.

  4. Effects of hamstring stretch with pelvic control on pain and work ability in standing workers.

    PubMed

    Han, Hyun-Il; Choi, Ho-Suk; Shin, Won-Seob

    2016-11-21

    Hamstring tightness induces posterior pelvic tilt and decreased lumbar lordosis, which can result in low back painOBJECTIVE: We investigated effects of hamstring stretch with pelvic control on pain and work ability in standing workers. One hundred adult volunteers from a standing workers were randomly assigned to pelvic control hamstring stretching (PCHS) (n = 34), general hamstring stretching (GHS) (n = 34), control (n = 32) groups. The control group was performed self-home exercise. All interventions were conducted 3 days per week for 6 weeks, and included in the hamstring stretching and lumbopelvic muscle strengthening. Outcomes were evaluated through the visual analog scale (VAS), straight leg raise test (SLR), sit and reach test (SRT), Oswestry disability index (ODI), and work ability index (WAI). Significant difference in VAS, SLR, SRT, ODI, and WAI were found in the PCHS and GHS groups. The control group was a significant difference only in ODI. The PCHS group showed a greater difference than the GHS group and control group in VAS, SLR, SRT, and ODI. The pelvic control hamstring stretch exercise would be more helpful in back pain reduction and improvement of work ability in an industrial setting.

  5. Wechsler Adult Intelligence Scale-Fourth Edition performance in relapsing-remitting multiple sclerosis.

    PubMed

    Ryan, Joseph J; Gontkovsky, Samuel T; Kreiner, David S; Tree, Heather A

    2012-01-01

    Forty patients with relapsing-remitting multiple sclerosis (MS) completed the 10 core Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) subtests. Means for age and education were 42.05 years (SD = 9.94) and 14.33 years (SD = 2.40). For all participants, the native language was English. The mean duration of MS diagnosis was 8.17 years (SD = 7.75), and the mean Expanded Disability Status Scale (EDSS; Kurtzke, 1983 ) score was 3.73 (SD = 1.41) with a range from 2.0 to 6.5. A control group of healthy individuals with similar demographic characteristics also completed the WAIS-IV and were provided by the test publisher. Compared to controls, patients with MS earned significantly lower subtest and composite scores. The patients' mean scores were consistently in the low-average to average range, and the patterns of performance across groups did not differ significantly, although there was a trend towards higher scores on the Verbal Comprehension Index (VCI) and lower scores on the Processing Speed Index (PSI). Approximately 78% of patients had actual Full Scale IQs that were significantly lower than preillness, demographically based IQ estimates.

  6. Aprotic solvents effect on the UV-visible absorption spectra of bixin.

    PubMed

    Rahmalia, Winda; Fabre, Jean-François; Usman, Thamrin; Mouloungui, Zéphirin

    2014-10-15

    We describe here the effects of aprotic solvents on the spectroscopic characteristics of bixin. Bixin was dissolved in dimethyl sulfoxide, acetone, dichloromethane, ethyl acetate, chloroform, dimethyl carbonate, cyclohexane and hexane, separately, and its spectra in the resulting solutions were determined by UV-visible spectrophotometry at normal pressure and room temperature. We analyzed the effect of aprotic solvents on λmax according to Onsager cavity model and Hansen theory, and determined the approximate absorption coefficient with the Beer-Lambert law. We found that the UV-visible absorption spectra of bixin were found to be solvent dependent. The S0→S2 transition energy of bixin in solution was dependent principally on the refractive index of the solvents and the bixin-solvent dispersion interaction. There was a small influence of the solvents dielectric constant, permanent dipole interaction and hydrogen bonding occurred between bixin and solvents. The absorbance of bixin in various solvents, with the exception of hexane, increased linearly with concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. High refractive index nanocomposite fluids for immersion lithography.

    PubMed

    Bremer, L; Tuinier, R; Jahromi, S

    2009-02-17

    The concept of using dispersions of nanoparticles as high refractive index fluids in immersion lithography is examined both from a theoretical and experimental point of view. In the theoretical part we show that gelation and demixing can be controlled in high solid dispersions, needed to achieve a high (refractive) index, by using short stabilizing brushes. We considered both fluid-fluid demixing by using statistical thermodynamics and percolation, computed using liquid-state approaches. Whenever demixing or percolation takes place, the nanoparticle dispersion is unsuited for immersion lithography. The minimum thickness of the stabilizer layer of a stable suspension is estimated assuming particles plus steric stabilizer to act as hard spheres with van der Waals attraction between the cores. Since the van der Waals attraction can be related to the optical properties of the particles and dispersion medium, it is also possible to estimate the refractive index that can be attained with composite immersion fluids. Using materials that are known to be highly transparent in the bulk at a wavelength of 193 nm, indices above 1.8 can be attained. Other materials with higher indices are expected to be transparent at 193 nm due to a blue shift of the UV absorption and enable much higher indices. In the experiment, we show that it is possible to prepare suspensions with particles of about 4 nm diameter that increase the refractive index of the continuous phase with 0.2 at a wavelength of 193 nm. The refractive index and density of such dispersions are proportional to the volume fraction of the disperse phase, and it is shown that the refractive index of the composite fluid can be predicted very well from the optical properties of the components. Furthermore, successful imaging experiments were performed through a dispersion of silica nanoparticles. These findings lead to the conclusion that immersion lithography using nanoparticle dispersions is indeed possible.

  8. Neurocognitive function in clinically stable individuals with long-term bipolar I disorder: Comparisons with schizophrenia patients and controls.

    PubMed

    Lin, Pei-Yun; Wang, Peng-Wei; Chen, Cheng-Sheng; Yen, Cheng-Fang

    2017-05-01

    This study compared the levels of the five domains of neurocognitive function-executive function, attention, memory, verbal comprehension, and perceptual organization-among clinically stable individuals with long-term bipolar I disorder, individuals with long-term schizophrenia, and a group of controls. We recruited a total of 93 clinically stable individuals with bipolar I disorder, 94 individuals with schizophrenia, and 106 controls in this study. Their neurocognitive function was measured using a series of neurocognitive function tests: the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III), Line Cancellation Test, Visual Form Discrimination, Controlled Oral Word Association Test, Wisconsin Card Sorting Test, Continuous Performance Task, and Wechsler Memory Scale-Third Edition. Neurocognitive function was compared among the three groups through a multivariate analysis of variance. The results indicated that when the effect of age was controlled, clinically stable individuals with bipolar I disorder and those with schizophrenia demonstrated poor neurocognitive function on all tests except for the WAIS-III Similarity and Information and the Line Cancellation Test. The individuals with bipolar I disorder had similar levels of neurocognitive function compared with the schizophrenia group, but higher levels of neurocognitive function on the WAIS-III Comprehension, Controlled Oral Word Association Test, and Wechsler Memory Scale-Third Edition Auditory Immediate and Delayed Index and Visual Immediate and Delayed Index. The conclusions of this study suggest that compared with controls, individuals with long-term bipolar I disorder and those with long-term schizophrenia have poorer neurocognitive function, even when clinically stable. Individuals with long-term bipolar I disorder and those with long-term schizophrenia have similar levels of deficits in several domains of neurocognitive function. Copyright © 2017. Published by Elsevier Taiwan.

  9. Individual features, working conditions and work injuries are associated with work ability among nursing professionals.

    PubMed

    Fischer, Frida Marina; Martinez, Maria Carmen

    2013-01-01

    To investigate factors associated with work ability among nursing professionals. They comprised 514 nursing professionals (83.8% of the total number of workers) from a hospital in São Paulo, Brazil. In 2009, we conducted a cross-sectional study that was a part of a 5-year planned cohort study initiated in 2008. We administered a comprehensive questionnaire to the participants in order to obtain data on their sociodemographic characteristics, lifestyles, and working conditions. The questionnaire also contained the Brazilian versions of the following: the Job Stress Scale (JSS), Effort-Reward Imbalance (ERI) Questionnaire, Work-Related Activities That May Contribute To Job-Related Pain and/or Injury (WRAPI), and Work Ability Index (WAI). The results were analyzed using descriptive, bivariate, and multivariate linear regression analyses. On the WAI, 74.9% of the workers obtained a score of over 40 points (score range 7-49); the mean score was 42.3 points (SD=4.5). The final multivariate model showed that lower WAI scores were related to the work-related outcome, which was work injury, and the following individual characteristics and working conditions: body mass index (p=0.001), sex (female; p=0.002), sedentariness (p < 0.001), time in the profession (p=0.005), social support at work (p=0.003), effort-reward ratio (p=0.001), violence at work (p=0.005), WRAPI score (p < 0.001), and work injuries (yes; p=0.001). Various factors were associated with work ability. The results showed that a number of variables should be considered when planning and implementing actions to maintain or improve work ability among nursing professionals.

  10. Application of the SAROTA index in real-life scenario

    NASA Astrophysics Data System (ADS)

    Rojatkar, A.; Monebhurrun, V.

    2014-10-01

    A unique parameter referred to as the SAROTA index which accounts for both the specific absorption rate (SAR) and the over-the-air (OTA) performance of a mobile phone was previously proposed to characterize the real-life exposure. The applicability of the SAROTA index was confirmed using SAR and total radiated power (TRP) data obtained under laboratory conditions wherein the power control (PC) enforced on the mobile phone was implemented artificially. Herein the investigation is extended to measurements conducted for the speech mode of operation in real-life scenarios. Based on the actual PC implemented during the communication with the base station, the instantaneous and average real-life exposure experienced by the mobile phone user is analyzed and compared to the predicted SAROTA index. To capture the PC in real-time, a set of hardware modified phones with embedded network monitoring software are used. The instantaneous uplink transmit power level (TX_LEV) along with various downlink parameters such as the receive signal level (RX_LEV) and received signal quality (RX_QUAL) of the communication link are thus available for performing a comprehensive RF exposure analysis.

  11. Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica

    NASA Astrophysics Data System (ADS)

    Fegyveresi, John M.; Alley, Richard B.; Muto, Atsuhiro; Orsi, Anaïs J.; Spencer, Matthew K.

    2018-01-01

    Observations at the West Antarctic Ice Sheet (WAIS) Divide site show that near-surface snow is strongly altered by weather-related processes such as strong winds and temperature fluctuations, producing features that are recognizable in the deep ice core. Prominent glazed surface crusts develop frequently at the site during summer seasons. Surface, snow pit, and ice core observations made in this study during summer field seasons from 2008-2009 to 2012-2013, supplemented by automated weather station (AWS) data with short- and longwave radiation sensors, revealed that such crusts formed during relatively low-wind, low-humidity, clear-sky periods with intense daytime sunshine. After formation, such glazed surfaces typically developed cracks in a polygonal pattern likely from thermal contraction at night. Cracking was commonest when several clear days occurred in succession and was generally followed by surface hoar growth; vapor escaping through the cracks during sunny days may have contributed to the high humidity that favored nighttime formation of surface hoar. Temperature and radiation observations show that daytime solar heating often warmed the near-surface snow above the air temperature, contributing to upward mass transfer, favoring crust formation from below, and then surface hoar formation. A simple surface energy calculation supports this observation. Subsequent examination of the WDC06A deep ice core revealed that crusts are preserved through the bubbly ice, and some occur in snow accumulated during winters, although not as commonly as in summertime deposits. Although no one has been on site to observe crust formation during winter, it may be favored by greater wintertime wind packing from stronger peak winds, high temperatures and steep temperature gradients from rapid midwinter warmings reaching as high as -15 °C, and perhaps longer intervals of surface stability. Time variations in crust occurrence in the core may provide paleoclimatic

  12. Optimization of barrel temperature and kidney bean flour percentage based on various physical properties of extruded snacks.

    PubMed

    Agathian, G; Semwal, A D; Sharma, G K

    2015-07-01

    The aim of the experiment was to optimize barrel temperature (122 to 178 ± 0.5 °C) and red kidney bean flour percentage (KBF) (12 to 68 ± 0.5 %) based on physical properties of extrudates like flash off percentage, water absorption index (WAI), water solubility index (WSI), bulk density (BD), radial expansion ratio (RER) and overall acceptability (OAA) using single screw extruder. The study was carried out by central composite rotatable design (CCRD) using Response surface methodology (RSM) and moisture content of feed was kept as constant 16.0 ± 0.5 % throughout experiments. Mathematical models for various responses were found to fit significantly (P < 0.05) for prediction. Optimization of experimental conditions was carried out using numerical optimization technique and the optimum barrel temperature and kidney bean flour percentage were 120 °C (T1) & 142.62 °C (T2 = T3) and 20 % respectively with desirability value of 0.909. Experiments were carried out using predicted values and verified using t-test and coefficient of variation percentage. Extruded snack prepared with rice flour (80 %) and kidney bean flour (20 %) at optimized conditions was accepted by the taste panellists and above 20 % KB incorporation was found to decrease overall acceptability score.

  13. The Use of a Context-Based Information Retrieval Technique

    DTIC Science & Technology

    2009-07-01

    provided in context. Latent Semantic Analysis (LSA) is a statistical technique for inferring contextual and structural information, and previous studies...WAIS). 10 DSTO-TR-2322 1.4.4 Latent Semantic Analysis LSA, which is also known as latent semantic indexing (LSI), uses a statistical and...1.4.6 Language Models In contrast, natural language models apply algorithms that combine statistical information with semantic information. Semantic

  14. Iron absorption from Southeast Asian diets. II. Role of various factors that might explain low absorption.

    PubMed

    Hallberg, L; Björn-Rasmussen, E; Rossander, L; Suwanik, R

    1977-04-01

    Previously reported levels of iron absorption from common Southeast Asian meals composed of rice, vegetables, and spices were too low to be consistent with the known prevalence of iron deficiency. In the present paper the cause of the low absorption was systematically sought. Variables investigated comprised methodological errors, factors in the diet such as certain foodstuffs, or contaminants inhibiting the absorption and characteristics of the subjects accompanied by malabsorption of dietary iron. The latter was excluded by comparing the absorption from both wheat rolls and a composit rice meal in Thai and Swedish women using the absorption of a small dose of ferrous ascorbate as a common basis of comparison. Two main factors were identified as causing the low absorption in the previous studies: the homogenization of the labeled meals before serving and the use of rice flour instead of rice. Iron absorption from nonhomogenized meals of identical composition as studied previously was many times higher (on an average 0.16 mg) and was consistent with the actual prevalence of iron deficiency in lower socioeconomic groups of Thais mainly consuming the simple meals studied. Recent modifications of the method to measure nonheme iron absorption from composite meals have thus not only made the determination simpler but also more accurate.

  15. Examination of the Measurement of Absorption Using the Reverberant Room Method for Highly Absorptive Acoustic Foam

    NASA Technical Reports Server (NTRS)

    Hughes, William O.; McNelis, Anne M.; Chris Nottoli; Eric Wolfram

    2015-01-01

    The absorption coefficient for material specimens are needed to quantify the expected acoustic performance of that material in its actual usage and environment. The ASTM C423-09a standard, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberant Room Method" is often used to measure the absorption coefficient of material test specimens. This method has its basics in the Sabine formula. Although widely used, the interpretation of these measurements are a topic of interest. For example, in certain cases the measured Sabine absorption coefficients are greater than 1.0 for highly absorptive materials. This is often attributed to the diffraction edge effect phenomenon. An investigative test program to measure the absorption properties of highly absorbent melamine foam has been performed at the Riverbank Acoustical Laboratories. This paper will present and discuss the test results relating to the effect of the test materials' surface area, thickness and edge sealing conditions. A follow-on paper is envisioned that will present and discuss the results relating to the spacing between multiple piece specimens, and the mounting condition of the test specimen.

  16. Hard X-ray index of refraction tomography of a whole rabbit knee joint: A feasibility study.

    PubMed

    Gasilov, S; Mittone, A; Horng, A; Geith, T; Bravin, A; Baumbach, T; Coan, P

    2016-12-01

    We report results of the computed tomography reconstruction of the index of refraction in a whole rabbit knee joint examined at the photon energy of 51keV. Refraction based images make it possible to delineate the bone, cartilage, and soft tissues without adjusting the contrast window width and level. Density variations, which are related to tissue composition and are not visible in absorption X-ray images, are detected in the obtained refraction based images. We discuss why refraction-based images provide better detectability of low contrast features than absorption images. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Deep and tapered silicon photonic crystals for achieving anti-reflection and enhanced absorption.

    PubMed

    Hung, Yung-Jr; Lee, San-Liang; Coldren, Larry A

    2010-03-29

    Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic ellipsometer, the sub-wavelength periodic structure can provide a broad and angular-independent antireflective window in the visible region for the TE-polarized light. The PhCs with tapered rods can further reduce the reflection due to a gradually changed effective index. On the other hand, strong optical resonances for TM-mode can be found in this structure, which is mainly due to the existence of full photonic bandgaps inside the material. Such resonance can enhance the optical absorption inside the silicon PhCs due to its increased optical paths. With the help of both antireflective and absorption-enhanced characteristics in this structure, the PhCs can be used for various applications.

  18. Semiconductor-metal graded-index composite thin films for infrared applications

    NASA Technical Reports Server (NTRS)

    Lamb, James L.; Nagendra, C. L.

    1994-01-01

    Theoretical/experimental studies have been carried out on germanium:silver (Ge:Ag) graded-index composite thin films which demonstrate that graded coatings, consisting of varied concentrations of Ag with respect to the Ge film thickness, exhibit different optical properties ranging from selective infrared (IR) reflectance to broadband IR absorptance. The graded coatings have been produced by dc magnetron cosputtering of Ge and Ag and the spectral properties are found to be stable against temperature. The coatings have been applied to an infrared tunnel sensor (micro-Golay cell) to improve the device performance.

  19. Design for approaching Cicada-wing reflectance in low- and high-index biomimetic nanostructures.

    PubMed

    Huang, Yi-Fan; Jen, Yi-Jun; Chen, Li-Chyong; Chen, Kuei-Hsien; Chattopadhyay, Surojit

    2015-01-27

    Natural nanostructures in low refractive index Cicada wings demonstrate ≤ 1% reflectance over the visible spectrum. We provide design parameters for Cicada-wing-inspired nanotip arrays as efficient light harvesters over a 300-1000 nm spectrum and up to 60° angle of incidence in both low-index, such as silica and indium tin oxide, and high-index, such as silicon and germanium, photovoltaic materials. Biomimicry of the Cicada wing design, demonstrating gradient index, onto these material surfaces, either by real electron cyclotron resonance microwave plasma processing or by modeling, was carried out to achieve a target reflectance of ∼ 1%. Design parameters of spacing/wavelength and length/spacing fitted into a finite difference time domain model could simulate the experimental reflectance values observed in real silicon and germanium or in model silica and indium tin oxide nanotip arrays. A theoretical mapping of the length/spacing and spacing/wavelength space over varied refractive index materials predicts that lengths of ∼ 1.5 μm and spacings of ∼ 200 nm in high-index and lengths of ∼ 200-600 nm and spacings of ∼ 100-400 nm in low-index materials would exhibit ≤ 1% target reflectance and ∼ 99% optical absorption over the entire UV-vis region and angle of incidence up to 60°.

  20. Unusual continuous dual absorption peaks in Ca-doped BiFeO3 nanostructures for broadened microwave absorption

    NASA Astrophysics Data System (ADS)

    Li, Zhong-Jun; Hou, Zhi-Ling; Song, Wei-Li; Liu, Xing-Da; Cao, Wen-Qiang; Shao, Xiao-Hong; Cao, Mao-Sheng

    2016-05-01

    Electromagnetic absorption materials have received increasing attention owing to their wide applications in aerospace, communication and the electronics industry, and multiferroic materials with both polarization and magnetic properties are considered promising ceramics for microwave absorption application. However, the insufficient absorption intensity coupled with the narrow effective absorption bandwidth has limited the development of high-performance multiferroic materials for practical microwave absorption. To address such issues, in the present work, we utilize interfacial engineering in BiFeO3 nanoparticles via Ca doping, with the purpose of tailoring the phase boundary. Upon Ca-substitution, the co-existence of both R3c and P4mm phases has been confirmed to massively enhance both dielectric and magnetic properties via manipulating the phase boundary and the destruction of the spiral spin structure. Unlike the commonly reported magnetic/dielectric hybrid microwave absorption composites, Bi0.95Ca0.05FeO3 has been found to deliver unusual continuous dual absorption peaks at a small thickness (1.56 mm), which has remarkably broadened the effective absorption bandwidth (8.7-12.1 GHz). The fundamental mechanisms based on the phase boundary engineering have been discussed, suggesting a novel platform for designing advanced multiferroic materials with wide applications.Electromagnetic absorption materials have received increasing attention owing to their wide applications in aerospace, communication and the electronics industry, and multiferroic materials with both polarization and magnetic properties are considered promising ceramics for microwave absorption application. However, the insufficient absorption intensity coupled with the narrow effective absorption bandwidth has limited the development of high-performance multiferroic materials for practical microwave absorption. To address such issues, in the present work, we utilize interfacial engineering in BiFeO3

  1. Dependence of the Broad Absorption Line Quasar Fraction on Radio Luminosity

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Dai, Xinyu; Sivakoff, Gregory R.

    2008-11-01

    We find that the fraction of classical broad absorption line quasars (BALQSOs) among the FIRST radio sources in the Sloan Data Release 3, is 20.5+ 7.3-5.9% at the faintest radio powers detected (L1.4 GHz ~ 1032 erg s-1), and rapidly drops to lesssim8% at L1.4 GHz ~ 3 × 1033 erg s-1. Similarly, adopting the broader absorption index (AI) definition of Trump et al., we find the fraction of radio BALQSOs to be 44+ 8.1-7.8%, reducing to 23.1+ 7.3-6.1% at high luminosities. While the high fraction at low radio power is consistent with the recent near-IR estimates by Dai et al., the lower fraction at high radio powers is intriguing and confirms previous claims based on smaller samples. The trend is independent of the redshift range, the optical and radio flux selection limits, or the exact definition of a radio match. We also find that at fixed optical magnitude, the highest bins of radio luminosity are preferentially populated by non-BALQSOs, consistent with the overall trend. We do find, however, that those quasars identified as AI-BALQSOs but not under the classical definition do not show a significant drop in their fraction as a function of radio power, further supporting independent claims that these sources, characterized by lower equivalent width, may represent an independent class from the classical BALQSOs. We find the balnicity index, a measure of the absorption trough in BALQSOs, and the mean maximum wind velocity to be roughly constant at all radio powers. We discuss several plausible physical models which may explain the observed fast drop in the fraction of the classical BALQSOs with increasing radio power, although none is entirely satisfactory. A strictly evolutionary model for the BALQSO and radio emission phases requires a strong fine-tuning to work, while a simple geometric model, although still not capable of explaining polar BALQSOs and the paucity of FRII BALQSOs, is statistically successful in matching the data if part of the apparent radio

  2. Absorption fluids data survey

    NASA Astrophysics Data System (ADS)

    Macriss, R. A.; Zawacki, T. S.

    Development of improved data for the thermodynamic, transport and physical properties of absorption fluids were studied. A specific objective of this phase of the study is to compile, catalog and coarse screen the available US data of known absorption fluid systems and publish it as a first edition document to be distributed to manufacturers, researchers and others active in absorption heat pump activities. The methodology and findings of the compilation, cataloguing and coarse screening of the available US data on absorption fluid properties and presents current status and future work on this project are summarized. Both in house file and literature searches were undertaken to obtain available US publications with pertinent physical, thermodynamic and transport properties data for absorption fluids. Cross checks of literature searches were also made, using available published bibliographies and literature review articles, to eliminate secondary sources for the data and include only original sources and manuscripts. The properties of these fluids relate to the liquid and/or vapor state, as encountered in normal operation of absorption equipment employing such fluids, and to the crystallization boundary of the liquid phase, where applicable. The actual data were systematically classified according to the type of fluid and property, as well as temperature, pressure and concentration ranges over which data were available. Data were sought for 14 different properties: Vapor-Liquid Equilibria, Crystallization Temperature, Corrosion Characteristics, Heat of Mixing, Liquid-Phase-Densities, Vapor-Liquid-Phase Enthalpies, Specific Heat, Stability, Viscosity, Mass Transfer Rate, Heat Transfer Rate, Thermal Conductivity, Flammability, and Toxicity.

  3. Tunneling induced absorption with competing Nonlinearities

    PubMed Central

    Peng, Yandong; Yang, Aihong; Xu, Yan; Wang, Peng; Yu, Yang; Guo, Hongju; Ren, Tingqi

    2016-01-01

    We investigate tunneling induced nonlinear absorption phenomena in a coupled quantum-dot system. Resonant tunneling causes constructive interference in the nonlinear absorption that leads to an increase of more than an order of magnitude over the maximum absorption in a coupled quantum dot system without tunneling. Resonant tunneling also leads to a narrowing of the linewidth of the absorption peak to a sublinewidth level. Analytical expressions show that the enhanced nonlinear absorption is largely due to the fifth-order nonlinear term. Competition between third- and fifth-order nonlinearities leads to an anomalous dispersion of the total susceptibility. PMID:27958303

  4. Tunneling induced absorption with competing Nonlinearities.

    PubMed

    Peng, Yandong; Yang, Aihong; Xu, Yan; Wang, Peng; Yu, Yang; Guo, Hongju; Ren, Tingqi

    2016-12-13

    We investigate tunneling induced nonlinear absorption phenomena in a coupled quantum-dot system. Resonant tunneling causes constructive interference in the nonlinear absorption that leads to an increase of more than an order of magnitude over the maximum absorption in a coupled quantum dot system without tunneling. Resonant tunneling also leads to a narrowing of the linewidth of the absorption peak to a sublinewidth level. Analytical expressions show that the enhanced nonlinear absorption is largely due to the fifth-order nonlinear term. Competition between third- and fifth-order nonlinearities leads to an anomalous dispersion of the total susceptibility.

  5. An inulin-type fructan enhances calcium absorption primarily via an effect on colonic absorption in humans

    USDA-ARS?s Scientific Manuscript database

    Calcium absorption efficiency and bone mineral mass are increased in adolescents who regularly consume inulin-type fructans (ITF). The mechanism of action in increasing absorption is unknown but may be related to increased colonic calcium absorption. We conducted a study in young adults designed to ...

  6. The application of reduced absorption cross section on the identification of the compounds with similar function-groups

    NASA Astrophysics Data System (ADS)

    Yu, Fei; Zuo, Jian; Mu, Kai-jun; Zhang, Zhen-wei; Zhang, Liang-liang; Zhang, Lei-wei; Zhang, Cun-lin

    2013-08-01

    Terahertz spectroscopy is a powerful tool for materials investigation. The low frequency vibrations were usually investigated by means of absorption coefficient regardless of the refractive index. It leads to the disregard of some inherent low-frequency vibrational information of the chemical compounds. Moreover, due to the scattering inside the sample, there are some distortions of the absorption features, so that the absorption dependent material identification is not valid enough. Here, a statistical parameter named reduced absorption cross section (RACS) is introduced. This can not only help us investigate the molecular dynamics but also distinguish one chemical compound with another which has similar function-groups. Experiments are carried out on L-Tyrosine and L-Phenylalanine and the different mass ratios of their mixtures as an example of the application of RACS. The results come out that the RACS spectrum of L-Tyrosine and L-Phenylalanine reserve the spectral fingerprint information of absorption spectrum. The log plot of RACSs of the two amino acids show power-law behavior σR(~ν) ~ (ν~α), and there is a linear relation between the wavenumber and the RACS in the double logarithmic plot. The exponents α, at the same time, are the slopes of the RACS curves in the double logarithmic plot. The big differences of the exponents α between the two amino acids and their mixtures can be seen visually from the slopes of the RACS curves. So we can use RACS analytical method to distinguish some complex compounds with similar function-groups and mixtures from another which has similar absorption peaks in THz region.

  7. Solar absorption surface panel

    DOEpatents

    Santala, Teuvo J.

    1978-01-01

    A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

  8. A method for the detection of the refractive index of irregular shape solid pigments in light absorbing liquid matrix.

    PubMed

    Niskanen, Ilpo; Räty, Jukka; Peiponen, Kai-Erik

    2010-06-15

    The immersion liquid method is powerful for the measurement of the refractive index of solid particles in a liquid matrix. However, this method applies best for cases when the liquid matrix is transparent. A problem is usually how to assess the refractive index of a pigment when it is in a colored host liquid. In this article we introduce a method, and show that by combining so-called multifunction spectrophotometer, immersion liquid method and detection of light transmission and reflection we can assess the refractive index of a pigment in a colored liquid, and also the extinction or absorption coefficient of the host liquid.

  9. A fibre-coupled UHV-compatible variable angle reflection-absorption UV/visible spectrometer

    NASA Astrophysics Data System (ADS)

    Stubbing, J. W.; Salter, T. L.; Brown, W. A.; Taj, S.; McCoustra, M. R. S.

    2018-05-01

    We present a novel UV/visible reflection-absorption spectrometer for determining the refractive index, n, and thicknesses, d, of ice films. Knowledge of the refractive index of these films is of particular relevance to the astrochemical community, where they can be used to model radiative transfer and spectra of various regions of space. In order to make these models more accurate, values of n need to be recorded under astronomically relevant conditions, that is, under ultra-high vacuum (UHV) and cryogenic cooling. Several design considerations were taken into account to allow UHV compatibility combined with ease of use. The key design feature is a stainless steel rhombus coupled to an external linear drive (z-shift) allowing a variable reflection geometry to be achieved, which is necessary for our analysis. Test data for amorphous benzene ice are presented as a proof of concept, the film thickness, d, was found to vary linearly with surface exposure, and a value for n of 1.43 ± 0.07 was determined.

  10. A study on the relationships between age, work experience, cognition, and work ability in older employees working in heavy industry.

    PubMed

    Chung, Jaeyeop; Park, Juhyung; Cho, Milim; Park, Yunhee; Kim, DeokJu; Yang, Dongju; Yang, Yeongae

    2015-01-01

    [Purpose] The purpose of this study was to examine the correlation of age, work experience, cognition, and work ability in older employees working in heavy industry. [Subjects and Methods] The study was conducted using 100 subjects who were over 55 years old and worked in heavy industry. To obtain data, we first had the subjects complete the MoCA-K test and Work Ability Index (WAI). The data were then analyzed by frequency and correlation using statistical software (SPSS 21.0). [Results] Through this study, we discovered a significant positive correlation between WAI and MoCA-K, age, and work experience. [Conclusion] This study revealed that work ability in older employees increases not with the number of years worked but with the enhancement of cognitive ability. Special management that focuses on cognition is therefore required for senior employees working in the field of heavy industry.

  11. A gender approach to work ability and its relationship to professional and domestic work hours among nursing personnel.

    PubMed

    Rotenberg, Lúcia; Portela, Luciana Fernandes; Banks, Bahby; Griep, Rosane Harter; Fischer, Frida Marina; Landsbergis, Paul

    2008-09-01

    The association between working hours and work ability was examined in a cross-sectional study of male (N=156) and female (N=1092) nurses in three public hospitals. Working hours were considered in terms of their professional and domestic hours per week and their combined impact; total work load. Logistic regression analysis showed a significant association between total work load and inadequate work ability index (WAI) for females only. Females reported a higher proportion of inadequate WAI, fewer professional work hours but longer domestic work hours. There were no significant differences in total work load by gender. The combination of professional and domestic work hours in females seemed to best explain their lower work ability. The findings suggest that investigations into female well-being need to consider their total work load. Our male sample may have lacked sufficient power to detect a relationship between working hours and work ability.

  12. The Influence of Cognitive Reserve on Recovery from Traumatic Brain Injury.

    PubMed

    Donders, Jacobus; Stout, Jacob

    2018-04-12

    we sought to determine the degree to which cognitive reserve, as assessed by the Test of Premorbid Functioning in combination with demographic variables, could act as a buffer against the effect of traumatic brain injury (TBI) on cognitive test performance. retrospective analysis of a cohort of 121 persons with TBI who completed the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) within 1-12 months after injury. regression analyses indicated that cognitive reserve was a statistically significant predictor of all postinjury WAIS-IV factor index scores, after controlling for various premorbid and comorbid confounding variables. Only for Processing Speed did injury severity make an additional statistically significant contribution to the prediction model. cognitive reserve has a protective effect with regard to the impact of TBI on cognitive test performance but this effect is imperfect and does not completely negate the effect of injury severity.

  13. Differential-optoacoustic absorption detector

    NASA Technical Reports Server (NTRS)

    Shumate, M. S.

    1977-01-01

    Two-cell spectrophone detects trace amounts of atmospheric pollutants by measuring absorption coefficients of gases with various laser sources. Device measures pressure difference between two tapered cells with differential manometer. Background signal is reduced by balanced window heating and balanced carrier gas absorption in two cells.

  14. Ultraviolet absorption spectrum of HOCl

    NASA Technical Reports Server (NTRS)

    Burkholder, James B.

    1993-01-01

    The room temperature UV absorption spectrum of HOCl was measured over the wavelength range 200 to 380 nm with a diode array spectrometer. The absorption spectrum was identified from UV absorption spectra recorded following UV photolysis of equilibrium mixtures of Cl2O/H2O/HOCl. The HOCl spectrum is continuous with a maximum at 242 nm and a secondary peak at 304 nm. The measured absorption cross section at 242 nm was (2.1 +/- 0.3) x 10 exp -19/sq cm (2 sigma error limits). These results are in excellent agreement with the work of Knauth et al. (1979) but in poor agreement with the more recent measurements of Mishalanie et al. (1986) and Permien et al. (1988). An HOCl nu2 infrared band intensity of 230 +/- 35/sq cm atm was determined based on this UV absorption cross section. The present results are compared with these previous measurements and the discrepancies are discussed.

  15. Detection of non-absorbing charge dynamics via refractive index change in dye-sensitized solar cells.

    PubMed

    Kuwahara, Shota; Hata, Hiroaki; Taya, Soichiro; Maeda, Naotaka; Shen, Qing; Toyoda, Taro; Katayama, Kenji

    2013-04-28

    The carrier dynamics in dye-sensitized solar cells was investigated by using the transient grating, in addition to the transient absorption method and transient photocurrent method on the order of microseconds to seconds. The signals for the same sample were obtained under a short-circuit condition to compare the carrier dynamics via refractive index change with the transient photocurrent measurement. Optically silent carrier dynamics by transient absorption have been successfully observed via a refractive index change. The corresponding signal components were originated from the charge dynamics at the solid/liquid interface, especially on the liquid side; rearrangement or diffusion motion of charged redox species occurred when the injected electrons were trapped at the TiO2 surface and when the electron-electrolyte recombination occurred at the interface. The assignments were confirmed from the dependence on the viscosity of the solvent and the presence of 4-tert-butyl pyridine. As the viscosity of the solvent increased, the rearrangement and the motion of the charged redox species were delayed. Since the rearrangement dynamics was changed by the presence of 4-tert-butyl pyridine, it affected not only the TiO2 surface but also the redox species close to the interface.

  16. Dependence of the absorption and optical surface plasmon scattering of MoS₂ nanoparticles on aspect ratio, size, and media.

    PubMed

    Yadgarov, Lena; Choi, Charina L; Sedova, Anastasiya; Cohen, Ayala; Rosentsveig, Rita; Bar-Elli, Omri; Oron, Dan; Dai, Hongjie; Tenne, Reshef

    2014-04-22

    The optical and electronic properties of suspensions of inorganic fullerene-like nanoparticles of MoS2 are studied through light absorption and zeta-potential measurements and compared to those of the corresponding microscopic platelets. The total extinction measurements show that, in addition to excitonic peaks and the indirect band gap transition, a new peak is observed at 700-800 nm. This spectral peak has not been reported previously for MoS2. Comparison of the total extinction and decoupled absorption spectrum indicates that this peak largely originates from scattering. Furthermore, the dependence of this peak on nanoparticle size, shape, and surface charge, as well as solvent refractive index, suggests that this transition arises from a plasmon resonance.

  17. Modeling seasonal changes in live fuel moisture and equivalent water thickness using a cumulative water balance index

    Treesearch

    Philip E. Dennison; Dar A. Roberts; Sommer R. Thorgusen; Jon C. Regelbrugge; David Weise; Christopher Lee

    2003-01-01

    Live fuel moisture, an important determinant of fire danger in Mediterranean ecosystems, exhibits seasonal changes in response to soil water availability. Both drought stress indices based on meteorological data and remote sensing indices based on vegetation water absorption can be used to monitor live fuel moisture. In this study, a cumulative water balance index (...

  18. Unusual continuous dual absorption peaks in Ca-doped BiFeO3 nanostructures for broadened microwave absorption.

    PubMed

    Li, Zhong-Jun; Hou, Zhi-Ling; Song, Wei-Li; Liu, Xing-Da; Cao, Wen-Qiang; Shao, Xiao-Hong; Cao, Mao-Sheng

    2016-05-21

    Electromagnetic absorption materials have received increasing attention owing to their wide applications in aerospace, communication and the electronics industry, and multiferroic materials with both polarization and magnetic properties are considered promising ceramics for microwave absorption application. However, the insufficient absorption intensity coupled with the narrow effective absorption bandwidth has limited the development of high-performance multiferroic materials for practical microwave absorption. To address such issues, in the present work, we utilize interfacial engineering in BiFeO3 nanoparticles via Ca doping, with the purpose of tailoring the phase boundary. Upon Ca-substitution, the co-existence of both R3c and P4mm phases has been confirmed to massively enhance both dielectric and magnetic properties via manipulating the phase boundary and the destruction of the spiral spin structure. Unlike the commonly reported magnetic/dielectric hybrid microwave absorption composites, Bi0.95Ca0.05FeO3 has been found to deliver unusual continuous dual absorption peaks at a small thickness (1.56 mm), which has remarkably broadened the effective absorption bandwidth (8.7-12.1 GHz). The fundamental mechanisms based on the phase boundary engineering have been discussed, suggesting a novel platform for designing advanced multiferroic materials with wide applications.

  19. Solar cells based on particulate structure of active layer: Investigation of light absorption by an ordered system of spherical submicron silicon particles

    NASA Astrophysics Data System (ADS)

    Miskevich, Alexander A.; Loiko, Valery A.

    2015-12-01

    Enhancement of the performance of photovoltaic cells through increasing light absorption due to optimization of an active layer is considered. The optimization consists in creation of particulate structure of active layer. The ordered monolayers and multilayers of submicron crystalline silicon (c-Si) spherical particles are examined. The quasicrystalline approximation (QCA) and the transfer matrix method (TMM) are used to calculate light absorption in the wavelength range from 0.28 μm to 1.12 μm. The integrated over the terrestial solar spectral irradiance "Global tilt" ASTM G173-03 absorption coefficient is calculated. In the wavelength range of small absorption index of c-Si (0.8-1.12 μm) the integral absorption coefficient of monolayer can be more than 20 times higher than the one of the plane-parallel plate of the equivalent volume of material. In the overall considered range (0.28-1.12 μm) the enhancement factor up to ~1.45 for individual monolayer is observed. Maximum value of the spectral absorption coefficient approaches unity for multilayers consisting of large amount of sparse monolayers of small particles. Multilayers with variable concentration and size of particles in the monolayer sequences are considered. Absorption increasing by such gradient multilayers as compared to the non-gradient ones is illustrated. The considered structures are promising for creation of high efficiency thin-film solar cells.

  20. Apparatus and method for quantitative measurement of small differences in optical absorptivity between two samples using differential interferometry and the thermooptic effect

    DOEpatents

    Cremers, D.A.; Keller, R.A.

    1984-05-08

    An apparatus and method for the measurement of small differences in optical absorptivity of weakly absorbing solutions using differential interferometry and the thermooptic effect have been developed. Two sample cells are placed in each arm of an interferometer and are traversed by colinear probe and heating laser beams. The interrogation probe beams are recombined forming a fringe pattern, the intensity of which can be related to changes in optical path length of these laser beams through the cells. This in turn can be related to small differences in optical absorptivity which results in different amounts of sample heating when the heating laser beams are turned on, by the fact that the index of refraction of a liquid is temperature dependent. A critical feature of this invention is the stabilization of the optical path of the probe beams against drift. Background (solvent) absorption can then be suppressed by a factor of approximately 400. Solute absorptivities of about 10[sup [minus]5] cm[sup [minus]1] can then be determined in the presence of background absorptions in excess of 10[sup [minus]3] cm[sup [minus]1]. In addition, the smallest absorption measured with the instant apparatus and method is about 5 [times] 10[sup [minus]6] cm[sup [minus]1]. 6 figs.

  1. Apparatus and method for quantitative measurement of small differences in optical absorptivity between two samples using differential interferometry and the thermooptic effect

    DOEpatents

    Cremers, David A.; Keller, Richard A.

    1984-01-01

    An apparatus and method for the measurement of small differences in optical absorptivity of weakly absorbing solutions using differential interferometry and the thermooptic effect has been developed. Two sample cells are placed in each arm of an interferometer and are traversed by colinear probe and heating laser beams. The interrogation probe beams are recombined forming a fringe pattern, the intensity of which can be related to changes in optical pathlength of these laser beams through the cells. This in turn can be related to small differences in optical absorptivity which results in different amounts of sample heating when the heating laser beams are turned on, by the fact that the index of refraction of a liquid is temperature dependent. A critical feature of this invention is the stabilization of the optical path of the probe beams against drift. Background (solvent) absorption can then be suppressed by a factor of approximately 400. Solute absorptivities of about 10.sup.-5 cm.sup.-1 can then be determined in the presence of background absorptions in excess of 10.sup.-3 cm.sup.-1. In addition, the smallest absorption measured with the instant apparatus and method is about 5.times. 10.sup.-6 cm.sup.-1.

  2. Apparatus and method for quantitative measurement of small differences in optical absorptivity between two samples using differential interferometry and the thermooptic effect

    DOEpatents

    Cremers, D.A.; Keller, R.A.

    1982-06-08

    An apparatus and method for the measurement of small differences in optical absorptivity of weakly absorbing solutions using differential interferometry and the thermooptic effect has been developed. Two sample cells are placed in each arm of an interferometer and are traversed by colinear probe and heating laser beams. The interrogation probe beams are recombined forming a fringe pattern, the intensity of which can be related to changes in optical pathlength of these laser beams through the cells. This in turn can be related to small differences in optical absorptivity which results in different amounts of sample heating when the heating laser beams are turned on, by the fact that the index of refraction of a liquid is temperature dependent. A critical feature of this invention is the stabilization of the optical path of the probe beams against drift. Background (solvent) absorption can then be suppressed by a factor of approximately 400. Solute absorptivities of about 10/sup -5/ cm/sup -1/ can then be determined in the presence of background absorptions in excess of 10/sup -3/ cm/sup -1/. In addition, the smallest absorption measured with the instant apparatus and method is about 5 x 10/sup -6/ cm/sup -1/.

  3. Z-scan theory for nonlocal nonlinear media with simultaneous nonlinear refraction and nonlinear absorption.

    PubMed

    Rashidian Vaziri, Mohammad Reza

    2013-07-10

    In this paper, the Z-scan theory for nonlocal nonlinear media has been further developed when nonlinear absorption and nonlinear refraction appear simultaneously. To this end, the nonlinear photoinduced phase shift between the impinging and outgoing Gaussian beams from a nonlocal nonlinear sample has been generalized. It is shown that this kind of phase shift will reduce correctly to its known counterpart for the case of pure refractive nonlinearity. Using this generalized form of phase shift, the basic formulas for closed- and open-aperture beam transmittances in the far field have been provided, and a simple procedure for interpreting the Z-scan results has been proposed. In this procedure, by separately performing open- and closed-aperture Z-scan experiments and using the represented relations for the far-field transmittances, one can measure the nonlinear absorption coefficient and nonlinear index of refraction as well as the order of nonlocality. Theoretically, it is shown that when the absorptive nonlinearity is present in addition to the refractive nonlinearity, the sample nonlocal response can noticeably suppress the peak and enhance the valley of the Z-scan closed-aperture transmittance curves, which is due to the nonlocal action's ability to change the beam transverse dimensions.

  4. Invisible ink mark detection in the visible spectrum using absorption difference.

    PubMed

    Lee, Joong; Kong, Seong G; Kang, Tae-Yi; Kim, Byounghyun; Jeon, Oc-Yeub

    2014-03-01

    One of popular techniques in gambling fraud involves the use of invisible ink marks printed on the back surface of playing cards. Such covert patterns are transparent in the visible spectrum and therefore invisible to unaided human eyes. Invisible patterns can be made visible with ultraviolet (UV) illumination or a CCD camera installed with an infrared (IR) filter depending on the type of ink materials used. Cheating gamers often wear contact lenses or eyeglasses made of IR or UV filters to recognize the secret marks on the playing cards. This paper presents an image processing technique to reveal invisible ink patterns in the visible spectrum without the aid of special equipment such as UV lighting or IR filters. A printed invisible ink pattern leaves a thin coating on the surface with different refractive index for different wavelengths of light, which results in color dispersion or absorption difference. The proposed method finds the differences of color components caused by absorption difference to detect invisible ink patterns on the surface. Experiment results show that the proposed scheme is effective for both UV-active and IR-active invisible ink materials. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Access to DNA and protein databases on the Internet.

    PubMed

    Harper, R

    1994-02-01

    During the past year, the number of biological databases that can be queried via Internet has dramatically increased. This increase has resulted from the introduction of networking tools, such as Gopher and WAIS, that make it easy for research workers to index databases and make them available for on-line browsing. Biocomputing in the nineties will see the advent of more client/server options for the solution of problems in bioinformatics.

  6. Qualitative identification of food materials by complex refractive index mapping in the terahertz range.

    PubMed

    Shin, Hee Jun; Choi, Sung-Wook; Ok, Gyeongsik

    2018-04-15

    We investigated the feasibility of qualitative food analysis using complex refractive index mapping of food materials in the terahertz (THz) frequency range. We studied optical properties such as the refractive index and absorption coefficient of food materials, including insects as foreign substances, from 0.2 to 1.3 THz. Although some food materials had a complex composition, their refractive indices were approximated with effective medium values, and therefore, they could be discriminated on the complex refractive index map. To demonstrate food quality inspection with THz imaging, we obtained THz reflective images and time-of-flight imaging of hidden defects in a sugar and milk powder matrix by using time domain THz pulses. Our results indicate that foreign substances can be clearly classified and detected according to the optical parameters of the foods and insects by using THz pulses. Copyright © 2017. Published by Elsevier Ltd.

  7. Measurement properties of the Brazilian version of the Working Alliance Inventory (patient and therapist short-forms) and Session Rating Scale for low back pain.

    PubMed

    Araujo, Amanda Costa; Filho, Rúben Negrão; Oliveira, Crystian B; Ferreira, Paulo H; Pinto, Rafael Z

    2017-01-01

    In the low back pain (LBP) field, therapeutic alliance is considered a non-specific factor of interventions associated with improvements in clinical outcomes. However, there is a paucity of studies aimed to evaluate measurement properties of tools used to objectively quantify the alliance between therapist and patients, such as the Working Alliance Inventory (WAI) and Session Rating Scale (SRS). To translate and cross-culturally adapt the short-form version of WAI - therapist and SRS into Brazilian Portuguese; to investigate the measurement properties, of the WAI-Patient, WAI-Therapist and SRS in patients with LBP and their physical therapists, respectively. One hundred patients with LBP and 18 physical therapists were recruited from physical therapy clinics in Brazil. Therapeutic alliance measures were collected at the initial assessment, prior to the second session, and at 2-month follow-up. The measurement properties investigated were reproducibility, internal consistency, ceiling/floor effects and responsiveness. Although WAI-Patient, WAI-Therapist and SRS were considered to have acceptable test-retest reliability (ICC2,1 > 0.70), these questionnaires showed problems with other measurement properties. WAI-Patient showed problems with internal consistency (i.e. Cronbach's alpha < 0.70 for all subscales). Presence of ceiling effect (i.e. > 15% of participants with the maximum score) and poor internal responsiveness were found for the WAI-Patient (Effect size = 0.15; 84% CI: 0.04 to 0.29) and for the SRS (Effect size = 0.05; 84% CI: -0.22 to 0.11). The WAI-Therapist revealed slightly better measurement properties. We identified psychometric limitations with most measurement properties of the WAI questionnaires and SRS. Future studies are needed to refine these tools.

  8. The NLM Indexing Initiative's Medical Text Indexer.

    PubMed

    Aronson, Alan R; Mork, James G; Gay, Clifford W; Humphrey, Susanne M; Rogers, Willie J

    2004-01-01

    The Medical Text Indexer (MTI) is a program for producing MeSH indexing recommendations. It is the major product of NLM's Indexing Initiative and has been used in both semi-automated and fully automated indexing environments at the Library since mid 2002. We report here on an experiment conducted with MEDLINE indexers to evaluate MTI's performance and to generate ideas for its improvement as a tool for user-assisted indexing. We also discuss some filtering techniques developed to improve MTI's accuracy for use primarily in automatically producing the indexing for several abstracts collections.

  9. Evaluating Model Parameterizations of Submicron Aerosol Scattering and Absorption with in situ Data from ARCTAS 2008

    NASA Technical Reports Server (NTRS)

    Alvarado, Matthew J.; Lonsdale, Chantelle R.; Macintyre, Helen L.; Bian, Huisheng; Chin, Mian; Ridley, David A.; Heald, Colette L.; Thornhill, Kenneth L.; Anderson, Bruce E.; Cubison, Michael J.; hide

    2016-01-01

    Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9- 02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10-23 percent, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GCRT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction

  10. Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

    NASA Astrophysics Data System (ADS)

    Alvarado, Matthew J.; Lonsdale, Chantelle R.; Macintyre, Helen L.; Bian, Huisheng; Chin, Mian; Ridley, David A.; Heald, Colette L.; Thornhill, Kenneth L.; Anderson, Bruce E.; Cubison, Michael J.; Jimenez, Jose L.; Kondo, Yutaka; Sahu, Lokesh K.; Dibb, Jack E.; Wang, Chien

    2016-07-01

    Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10-23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction

  11. Determining CDOM Absorption Spectra in Diverse Aquatic Environments Using a Multiple Pathlength, Liquid Core Waveguide System

    NASA Technical Reports Server (NTRS)

    Miller, Richard L.; Belz, Mathias; DelCastillo, Carlos; Trzaska, Rick

    2001-01-01

    We evaluated the accuracy, sensitivity and precision of a multiple pathlength, liquid core waveguide (MPLCW) system for measuring colored dissolved organic matter (CDOM) absorption in the UV-visible spectral range (370-700 nm). The MPLCW has four optical paths (2.0, 9.8, 49.3, and 204 cm) coupled to a single Teflon AF sample cell. Water samples were obtained from inland, coastal and ocean waters ranging in salinity from 0 to 36 PSU. Reference solutions for the MPLCW were made having a refractive index of the sample. CDOM absorption coefficients, aCDOM, and the slope of the log-linearized absorption spectra, S, were compared with values obtained using a dual-beam spectrophotometer. Absorption of phenol red secondary standards measured by the MPLCW at 558 nm were highly correlated with spectrophotometer values and showed a linear response across all four pathlengths. Values of aCDOM measured using the MPLCW were virtually identical to spectrophotometer values over a wide range of concentrations. The dynamic range of aCDOM for MPLCW measurements was 0.002 - 231.5 m-1. At low CDOM concentrations spectrophotometric aCDOM were slightly greater than MPLCW values and showed larger fluctuations at longer wavelengths due to limitations in instrument precision. In contrast, MPLCW spectra followed an exponential to 600 nm for all samples.

  12. Spectral Absorption Properties of Atmospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Bergstrom, R. W.; Pilewskie, P.; Russell, P. B.; Redemann, J.; Bond, T. C.; Quinn, P. K.; Sierau, B.

    2007-01-01

    We have determined the solar spectral absorption optical depth of atmospheric aerosols for specific case studies during several field programs (three cases have been reported previously; two are new results). We combined airborne measurements of the solar net radiant flux density and the aerosol optical depth with a detailed radiative transfer model for all but one of the cases. The field programs (SAFARI 2000, ACE Asia, PRIDE, TARFOX, INTEX-A) contained aerosols representing the major absorbing aerosol types: pollution, biomass burning, desert dust and mixtures. In all cases the spectral absorption optical depth decreases with wavelength and can be approximated with a power-law wavelength dependence (Absorption Angstrom Exponent or AAE). We compare our results with other recent spectral absorption measurements and attempt to briefly summarize the state of knowledge of aerosol absorption spectra in the atmosphere. We discuss the limitations in using the AAE for calculating the solar absorption. We also discuss the resulting spectral single scattering albedo for these cases.

  13. Effects of operative conditions on products obtained of starch-oil mixtures by single-screw extrusion.

    PubMed

    Włodarczyk-Stasiak, Marzena; Mazurek, Artur; Jamroz, Jerzy

    2017-01-01

    d. The aim of the study was to evaluate the fat binding and physicochemical properties of the products under conditions of potato starch extrusion containing rapeseed or linseed oil and rapeseed oil with glycerol. The study dealt with the extrudates of potato starch produced with the addition of rape seed or linseed oil and rapeseed oil and glycerol at 22% humidity. The extrudates were obtained at two screw speeds: 80 rpm and 100 rpm. Extrudates containing rapeseed oil and glycerol (R6G) were obtained at a temperature distribution of 115/130/150°C, while those with the participation of rapeseed oil and linseed oil were obtained at 120/135/128°C. Water solubility index (WSI), water absorption index (WAI), specific surface area (SBET) and quantity of fat permanently bound were determined for the products obtained. When oils were added, the solubility of extrudates decreased as compared to the control samples (starch without oil; S). Rapeseed oil added to the starch mixture at the levels of 3 g and 6 g in had no sig- nificant effect on the solubility of the product and amounted to: 80.3–82.6% and 78–79.6%. The largest decrease in solubility (WSI, 55.4–57.1%) was demonstrated for samples with 6% addition of rapeseed oil and 10 g glycerol. For these samples (R6G), a significant increase in the index WAI (376–397%) was recorded. Extrudates obtained with the addition of 3 g of rapeseed oil absorbed slightly more water than those with 6 g of oil added. The specific surface area (SBET 230–256 m2/g) determined from the water vapor adsorption isotherm indicates no statistically significant difference at α = 0.05 for products with rapeseed oil, linseed oil, and controls. A significant increase in the specific surface area (SBET 284–347 m2/g) was observed for samples with 6g rapeseed oil and 10 g glycerol added. For samples with 3 g of rapeseed oil, the amount of bound fat was 1.9–2.1 g/100 g of starch and for 6% the

  14. Raman and CT scan mapping of chalcogenide glass diffusion generated gradient index profiles

    NASA Astrophysics Data System (ADS)

    Lindberg, G. P.; Berg, R. H.; Deegan, J.; Benson, R.; Salvaggio, P. S.; Gross, N.; Weinstein, B. A.; Gibson, D.; Bayya, S.; Sanghera, J.; Nguyen, V.; Kotov, M.

    2016-05-01

    Metrology of a gradient index (GRIN) material is non-trivial, especially in the realm of infrared and large refractive index. Traditional methods rely on index matching fluids which are not available for indexes as high as those found in the chalcogenide glasses (2.4-3.2). By diffusing chalcogenide glasses of similar composition one can blend the properties in a continuous way. In an effort to measure this we will present data from both x-ray computed tomography scans (CT scans) and Raman mapping scans of the diffusion profiles. Proof of concept measurements on undiffused bonded sheets of chalcogenide glasses were presented previously. The profiles measured will be of axially stacked sheets of chalcogenide glasses diffused to create a linear GRIN profile and nested tubes of chalcogenide glasses diffused to create a radial parabolic GRIN profile. We will show that the x-ray absorption in the CT scan and the intensity of select Raman peaks spatially measured through the material are indicators of the concentration of the diffusion ions and correlate to the spatial change in refractive index. We will also present finite element modeling (FEM) results and compare them to post precision glass molded (PGM) elements that have undergone CT and Raman mapping.

  15. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  16. [Shock absorption of mouthguard materials--influence of temperature conditions and shore hardness on shock absorption].

    PubMed

    Tomita, Takashi; Tsukimura, Naoki; Ohno, Shigeru; Umekawa, Yoshitada; Sawano, Muneyuki; Fujimoto, Toshiki; Takamura, Masaaki; Majima, Aiko; Katakura, Yuusuke; Kurata, Akemi; Ohyama, Tetsuo; Ishigami, Tomohiko

    2006-04-01

    To consider changes in the physical properties of mouthguard materials with the change of temperature, shock-absorbing examination and Shore hardness measurement of existing MG materials and other elastic materials were carried out. Both examinations were done under two temperature conditions: at room temperature (25 degrees C) and simulated intraoral temperature (37 degrees C). In addition, a comparative study of the relation between Shore hardness and shock absorption of the materials was made. A self-made drop impact machine was used for the shock-absorbing examination. The thickness of a sample was assumed to be 3 mm. The loading was applied by dropping 3 kinds of steel ball, phi 10 mm (4.0 g), phi 15 mm (13.7 g), and phi 20 mm (32.6 g) from a height of 60 cm. The shock absorption of all materials was compared by the maximum impact force. Shore hardness was measured based on the JIS standard. The shock absorption of each material showed a different tendency depending on the loading condition. Furthermore, the shock absorption of the same material showed different results depending on the temperature condition. Shore hardness measurements tended to show low values with the condition of 37 degrees C for all materials. From the relation between shock absorption and Shore hardness, it was confirmed that there is a correlation between hardness and the maximum impact force in the materials that showed shock absorption by elastic deformation. Some materials showed high shock absorption compared with existing MG materials.

  17. Mathematical model of zinc absorption: effects of dietary calcium, protein and iron on zinc absorption

    PubMed Central

    Miller, Leland V.; Krebs, Nancy F.; Hambidge, K. Michael

    2013-01-01

    A previously described mathematical model of Zn absorption as a function of total daily dietary Zn and phytate was fitted to data from studies in which dietary Ca, Fe and protein were also measured. An analysis of regression residuals indicated statistically significant positive relationships between the residuals and Ca, Fe and protein, suggesting that the presence of any of these dietary components enhances Zn absorption. Based on the hypotheses that (1) Ca and Fe both promote Zn absorption by binding with phytate and thereby making it unavailable for binding Zn and (2) protein enhances the availability of Zn for transporter binding, the model was modified to incorporate these effects. The new model of Zn absorption as a function of dietary Zn, phytate, Ca, Fe and protein was then fitted to the data. The proportion of variation in absorbed Zn explained by the new model was 0·88, an increase from 0·82 with the original model. A reduced version of the model without Fe produced an equally good fit to the data and an improved value for the model selection criterion, demonstrating that when dietary Ca and protein are controlled for, there is no evidence that dietary Fe influences Zn absorption. Regression residuals and testing with additional data supported the validity of the new model. It was concluded that dietary Ca and protein modestly enhanced Zn absorption and Fe had no statistically discernable effect. Furthermore, the model provides a meaningful foundation for efforts to model nutrient interactions in mineral absorption. PMID:22617116

  18. Mathematical model of zinc absorption: effects of dietary calcium, protein and iron on zinc absorption.

    PubMed

    Miller, Leland V; Krebs, Nancy F; Hambidge, K Michael

    2013-02-28

    A previously described mathematical model of Zn absorption as a function of total daily dietary Zn and phytate was fitted to data from studies in which dietary Ca, Fe and protein were also measured. An analysis of regression residuals indicated statistically significant positive relationships between the residuals and Ca, Fe and protein, suggesting that the presence of any of these dietary components enhances Zn absorption. Based on the hypotheses that (1) Ca and Fe both promote Zn absorption by binding with phytate and thereby making it unavailable for binding Zn and (2) protein enhances the availability of Zn for transporter binding, the model was modified to incorporate these effects. The new model of Zn absorption as a function of dietary Zn, phytate, Ca, Fe and protein was then fitted to the data. The proportion of variation in absorbed Zn explained by the new model was 0·88, an increase from 0·82 with the original model. A reduced version of the model without Fe produced an equally good fit to the data and an improved value for the model selection criterion, demonstrating that when dietary Ca and protein are controlled for, there is no evidence that dietary Fe influences Zn absorption. Regression residuals and testing with additional data supported the validity of the new model. It was concluded that dietary Ca and protein modestly enhanced Zn absorption and Fe had no statistically discernable effect. Furthermore, the model provides a meaningful foundation for efforts to model nutrient interactions in mineral absorption.

  19. Measurements and Modeling of Aerosol Absorption and Single Scattering Albedo at Ambient Relative Hum

    NASA Technical Reports Server (NTRS)

    Redemann, J.; Russell, P. B.; Hamill, P.

    2000-01-01

    Uncertainties in the aerosol single scattering albedo have been identified to be an important source of errors in current large-scale model estimates of the direct aerosol radiative forcing of climate. A number of investigators have obtained estimates of the single scattering albedo from a variety of remote sensing and in situ measurements during aerosol field experiments. During the Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX, 1996) for example, estimates of the aerosol single scattering albedo were obtained (1) as a best-fit parameter in comparing radiative flux changes measured by airborne pyranometer to those computed from independently measured aerosol properties; (2) from estimates of the aerosol complex index of refraction derived using a combination of airborne sunphotometer, lidar backscatter and in situ size distribution measurements; and (3) from airborne measurements of aerosol scattering and absorption using nephelometers and absorption photometers. In this paper, we briefly compare the results of the latter two methods for two TARFOX case studies, since those techniques provide height-resolved information about the aerosol single scattering albedo. Estimates of the aerosol single scattering albedo from nephelometer and absorption photometer measurements require knowledge of the scattering and absorption humidification (i.e., the increase in these properties in response to an increase in ambient relative humidity), since both measurements are usually carried out at a relative humidity different from the ambient atmosphere. In principle, the scattering humidification factor can be measured, but there is currently no technique widely available to measure the absorption of an aerosol sample as a function of relative humidity. Frequently, for lack of better knowledge, the absorption humidification is assumed to be unity (meaning that there is no change in aerosol absorption due to an increase in ambient relative humidity). This

  20. Absorption of polycyclic aromatic hydrocarbons by a highly absorptive polymeric medium.

    PubMed

    Francisco, Olga; Idowu, Ifeoluwa; Friesen, Kelsey L; McDougall, Matthew; Choi, Sara Seoin; Bolluch, Patrique; Daramola, Oluwadamilola; Johnson, Wesley; Palace, Vince; Stetefeld, Jörg; Tomy, Gregg T

    2018-06-01

    The efficacy of a lightly cross-linked polymeric bead to absorb polycyclic aromatic hydrocarbons (PAHs) from the surface of fresh- and salt-water in a simulated oil-spill scenario was assessed in this study. A layer of PAHs at the water surface was created by first preparing the PAHs in hexane and then carefully spiking this mixture onto the surface of water. Beads were then applied to the surface of the organic phase and the amount of hydrocarbons absorbed by the beads was examined at prescribed time intervals and at different temperatures. Absorption of PAHs into the beads was exhaustive with ∼86 ± 4% being selectively removed from the organic phase by 120 s. First order reaction rates best described the uptake kinetics and absorption rates ranged from 0.0085 (naphthalene) to 0.0325 s- 1 (dibenzo[a,h]anthracene). Absorption of PAHs into the beads was driven by molecular volume (A 3 ). Uptake rates increased markedly for PAHs with molecular volumes between 130 A 3 and 190 A 3 . Beyond this molecular volume there was no apparent change in the rate of uptake. This study shows that these polymeric beads have a high affinity for PAHs and can be used under various environmental conditions with negligible difference in absorptive efficacy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

    NASA Astrophysics Data System (ADS)

    Anheier, N. C., Jr.; McDonald, C. E.; Cuta, J. M.; Cuta, F. M.; Olsen, K. B.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. Pacific Northwest Laboratory (PNL) researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation, sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH4(+)). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.

  2. Laser damage comparisons of broad-bandwidth, high-reflection optical coatings containing TiO 2, Nb 2O 5, or Ta 2O 5 high-index layers

    DOE PAGES

    Field, Ella Suzanne; Bellum, John Curtis; Kletecka, Damon E.

    2016-09-21

    Broad bandwidth coatings allow angle of incidence flexibility and accommodate spectral shifts due to aging and water absorption. Higher refractive index materials in optical coatings, such as TiO 2, Nb 2O 5, and Ta 2O 5, can be used to achieve broader bandwidths compared to coatings that contain HfO 2 high index layers. We have identified the deposition settings that lead to the highest index, lowest absorption layers of TiO 2, Nb 2O 5, and Ta 2O 5, via e-beam evaporation using ion-assisted deposition. We paired these high index materials with SiO 2 as the low index material to createmore » broad bandwidth high reflection coatings centered at 1054 nm for 45 deg angle of incidence and P polarization. Furthermore, high reflection bandwidths as large as 231 nm were realized. Laser damage tests of these coatings using the ISO 11254 and NIF-MEL protocols are presented, which revealed that the Ta 2O 5/SiO 2 coating exhibits the highest resistance to laser damage, at the expense of lower bandwidth compared to the TiO 2/SiO 2 and Nb 2O 5/SiO 2 coatings.« less

  3. Canopy structural complexity predicts forest canopy light absorption at continental scales

    NASA Astrophysics Data System (ADS)

    Atkins, J. W.; Fahey, R. T.; Hardiman, B. S.; Gough, C. M.

    2017-12-01

    Understanding how the physical structure of forest canopies influence light acquisition is a long-standing area of inquiry fundamental to advancing understanding of many areas of the physical sciences, including the modeling and interpretation of biogeochemical cycles. Conventional measures of forest canopy structure employed in earth system models are often limited to leaf area index (LAI)—a measure of the quantity of leaves in the canopy. However, more novel multi-dimensional measures of canopy structural complexity (CSC) that describe the arrangement of vegetation are now possible because of technological advances, and may improve modeled estimates of canopy light absorption. During 2016 and 2017, we surveyed forests at sites from across the eastern, southern, and midwestern United States using portable canopy LiDAR (PCL). This survey included 14 National Ecological Observation Network (NEON), Long-Term Ecological Research Network (LTER,) Ameriflux, and University affiliated sites. Our findings show that a composite model including CSC parameters and LAI explains 96.8% of the variance in light acquisition, measured as the fraction of photosynthetically absorbed radiation (fPAR) at the continental scale, and improvement of 12% over an LAI only model. Under high light sky conditions, measures of CSC are more strongly coupled with light acquisition than under low light, possibly because light scattering partially decouples CSC from canopy light absorption under low, predominately diffuse light conditions. We conclude that scalable estimates of CSC metrics may improve continent-wide estimates of canopy light absorption and, therefore, carbon uptake, with implications for remote sensing and earth system modeling.

  4. A First Estimation of County-Based Green Water Availability and Its Implications for Agriculture and Bioenergy Production in the United States

    DOE PAGES

    Xu, Hui; Wu, May

    2018-02-02

    Green water is vital for the terrestrial ecosystem, but water resource assessment often focuses on blue water. In this study, we estimated green water availability for major crops (i.e., corn, soybean, and wheat) and all other users(e.g., forest, grassland, and ecosystem services) at the county level in the United States. We estimated green water resources from effective rain(ER) using three different methods: Smith, U.S. Department of Agriculture-Soil Conservation Service (USDA-SCS), and the NHD plus V2 dataset. The analysis illustrates that, if green water meets all crop water demands, the fraction of green water resources available to all other users variesmore » significantly across regions, from the Northern Plains (0.71) to the Southeast (0.98). At the county level, this fraction varies from 0.23 to 1.0. Green water resources estimated using the three different ER methods present diverse spatiotemporal distribution patterns across regions, which could affect green water availability estimates. The water availability index for green water (WAI_R) was measured taking into account crop water demand and green water resources aggregated at the county level. Beyond these parameters, WAI_R also depends on the precipitation pattern, crop type and spatially differentiated regions. In addition, seasonal analysis indicated that WAI_R is sensitive to the temporal boundary of the analysis.« less

  5. Association between work ability and fatigue in Brazilian nursing workers.

    PubMed

    da Silva, Fabio José; Felli, Vanda Elisa Andres; Martinez, Maria Carmen; Mininel, Vivian Aline; Ratier, Ana Paula Pelegrini

    2015-01-01

    Impaired work ability is associated with work-related illnesses, early retirement and rising pension costs. To investigate the association between work ability and fatigue in nursing workers. Cross-sectional study conducted with 100 nursing workers from two inpatient units at a public teaching hospital in Sao Paulo, Brazil. The data were collected by means of a socio-demographic profile questionnaire, Work Ability Index (WAI) and Chalder Fatigue Scale. The data were analyzed by means of descriptive and analytical statistical methods, tests of association and multiple linear regression. The study population was mainly composed of women (88% ), exhibited a high educational level (76% ), average age 39.4 years old (SD = 9.5) and 15 years of professional experience, on average. The average score on WAI was good (39.4 points, SD = 6.0) but surprisingly, 35% of the participants exhibited moderate to poor work ability. Fatigue was found in 52% of the participants. The score on WAI decreased in association with fatigue (p <  0.001) and longer length of work in the same workplace (p = 0.001), as well as among nursing technicians compared to nurses (p = 0.040). Fatigue, longer length of work in the same workplace and work category nursing technician were associated with decreased work ability, which emphasizes the need for investment in health and quality of work life.

  6. A First Estimation of County-Based Green Water Availability and Its Implications for Agriculture and Bioenergy Production in the United States

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

    Xu, Hui; Wu, May

    Green water is vital for the terrestrial ecosystem, but water resource assessment often focuses on blue water. In this study, we estimated green water availability for major crops (i.e., corn, soybean, and wheat) and all other users(e.g., forest, grassland, and ecosystem services) at the county level in the United States. We estimated green water resources from effective rain(ER) using three different methods: Smith, U.S. Department of Agriculture-Soil Conservation Service (USDA-SCS), and the NHD plus V2 dataset. The analysis illustrates that, if green water meets all crop water demands, the fraction of green water resources available to all other users variesmore » significantly across regions, from the Northern Plains (0.71) to the Southeast (0.98). At the county level, this fraction varies from 0.23 to 1.0. Green water resources estimated using the three different ER methods present diverse spatiotemporal distribution patterns across regions, which could affect green water availability estimates. The water availability index for green water (WAI_R) was measured taking into account crop water demand and green water resources aggregated at the county level. Beyond these parameters, WAI_R also depends on the precipitation pattern, crop type and spatially differentiated regions. In addition, seasonal analysis indicated that WAI_R is sensitive to the temporal boundary of the analysis.« less

  7. Coupling between absorption and scattering in disordered colloids

    NASA Astrophysics Data System (ADS)

    Stephenson, Anna; Hwang, Victoria; Park, Jin-Gyu; Manoharan, Vinothan N.

    We aim to understand how scattering and absorption are coupled in disordered colloidal suspensions containing absorbing molecules (dyes). When the absorption length is shorter than the transport length, absorption dominates, and absorption and scattering can be seen as two additive effects. However, when the transport length is shorter than the absorption length, the scattering and absorption become coupled, as multiple scattering increases the path length of the light in the sample, leading to a higher probability of absorption. To quantify this synergistic effect, we measure the diffuse reflectance spectra of colloidal samples of varying dye concentrations, thicknesses, and particle concentrations, and we calculate the transport length and absorption length from our measurements, using a radiative transfer model. At particle concentrations so high that the particles form disordered packings, we find a minimum in the transport length. We show that selecting a dye where the absorption peak matches the location of the minimum in the transport length allows for enhanced absorption. Kraft-Heinz Corporation, NSF GRFP 2015200426.

  8. Compositional dependence of optical band gap and refractive index in lead and bismuth borate glasses

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

    Mallur, Saisudha B.; Czarnecki, Tyler; Adhikari, Ashish

    2015-08-15

    Highlights: • Refractive indices increase with increasing PbO/Bi{sub 2}O{sub 3} content. • Optical band gap arises due to direct forbidden transition. • Optical band gaps decrease with increasing PbO/Bi{sub 2}O{sub 3} content. • New empirical relation between the optical band gap and the refractive index. - Abstract: We prepared a series of lead and bismuth borate glasses by varying PbO/Bi{sub 2}O{sub 3} content and studied refractive index and optical band gap as a function of glass composition. Refractive indices were measured very accurately using a Brewster’s angle set up while the optical band gaps were determined by analyzing the opticalmore » absorption edge using the Mott–Davis model. Using the Lorentz–Lorentz method and the effective medium theory, we calculated the refractive indices and then compared them with the measured values. Bismuth borate glasses show better agreement between the calculated values of the refractive index and experimental values. We used a differential method based on Mott–Davis model to obtain the type of transition and optical band gap (E{sub opt}) which in turn was compared with the value of E{sub opt} obtained using the extinction coefficient. Our analysis shows that in both lead and bismuth borate glasses, the optical band gap arises due to direct forbidden transition. With increasing PbO/Bi{sub 2}O{sub 3} content, the absorption edge shifts toward longer wavelengths and the optical band gap decreases. This behavior can be explained in terms of changes to the Pb−O/Bi−O chemical bonds with glass composition. We obtained a new empirical relation between the optical band gap and the refractive index which can be used to accurately determine the electronic oxide polarizability in lead and bismuth oxide glasses.« less

  9. Influence of the West Antarctic Ice Sheet and its collapse on the wind and precipitation regimes of the Ross Embayment

    NASA Astrophysics Data System (ADS)

    Seles, D.; Kowalewski, D. E.

    2015-12-01

    Marine Isotope Stage 31 (MIS 31) is a key analogue for current warming trends yet the extent of the East Antarctic Ice Sheet (EAIS) and the West Antarctic Ice Sheet (WAIS) during this interglacial remains unresolved. Inconsistencies persist between offshore records (suggesting the instability of WAIS) and McMurdo Dry Valley (MDV) terrestrial datasets (indicating long-term ice sheet stability). Here we use a high-resolution regional scale climate model (RegCM3_Polar) to reconstruct paleoclimate during MIS 31 (warm orbit, 400 ppm CO2) and assess changes in precipitation and winds (including katabatic) with WAIS present versus WAIS absent. The MIS 31 scenario with WAIS present resulted in minimal changes in wind magnitude compared with current climate conditions. With WAIS absent, the model predicts a decrease in coastal and highland monthly mean average wind velocities. The greatest rates of snowfall remain along the coast but shift towards higher latitudes with the interior continent remaining dry when WAIS is removed. Focusing on the Ross Embayment, this decreased monthly mean wind velocity and shift of winds to the east indicate a greater influence of offshore winds from the Ross Sea, enabling the increase of precipitation southward along the Transantarctic Mountains (TAM) (i.e. MDV). The apparent decrease of katabatic winds with no WAIS implies that offshore winds may be responsible for bringing the warmer, wetter air into the TAM. The change in wind and precipitation in the Ross Embayment and specifically the MDV highlights the impact of WAIS on Antarctic climate and its subsequent influence on the mass balance of peripheral EAIS domes (i.e. Taylor Dome). Modeling suggests that if WAIS was absent during MIS 31, we would expect (1) greater accumulation at such domes and (2) MDV terrestrial records that reflect a wetter climate, and (3) weaker winds suggesting possibly lower ablation/erosion rates compared to if WAIS was present.

  10. Glucose absorption in acute peritoneal dialysis.

    PubMed

    Podel, J; Hodelin-Wetzel, R; Saha, D C; Burns, G

    2000-04-01

    During acute peritoneal dialysis (APD), it is known that glucose found in the dialysate solution contributes to the provision of significant calories. It has been well documented in continuous ambulatory peritoneal dialysis (CAPD) that glucose absorption occurs. In APD, however, it remains unclear how much glucose absorption actually does occur. Therefore, the purpose of this study was to determine whether it is appropriate to use the formula used to calculate glucose absorption in CAPD (Grodstein et al) among patients undergoing APD. Actual measurements of glucose absorption (Method I) were calculated in 9 patients undergoing APD treatment for >24 hours who were admitted to the intensive care unit. Glucose absorption using the Grodstein et al formula (Method II) was also determined and compared with the results of actual measurements. The data was then further analyzed based on the factors that influence glucose absorption, specifically dwell time and concentration. The mean total amount of glucose absorbed was 43% +/- 15%. However, when dwell time and concentration were further examined, significant differences were noted. Method I showed a cumulative increase over time. Method II showed that absorption was fixed. This suggests that with the variation in dwell time commonly seen in the acute care setting, the use of Method II may not be accurate. In each of the 2 methods, a significant difference in glucose absorption was noted when comparing the use of 1.5% and 4.25% dialysate concentrations. The established formula designed for CAPD should not be used for calculating glucose absorption in patients receiving APD because variation in dwell time and concentration should be taken into account. Because of the time constraints and staffing required to calculate each exchange individually, combined with the results of the study, we recommend the use of the percentage estimate of 40% to 50%.

  11. Imaginary refractive index and other microphysical properties of volcanic ash, Sarahan dust, and other mineral aerosols

    NASA Astrophysics Data System (ADS)

    Rocha Lima, A.; Martins, J.; Krotkov, N. A.; Artaxo, P.; Todd, M.; Ben Ami, Y.; Dolgos, G.; Espinosa, R.

    2013-12-01

    Aerosol properties are essential to support remote sensing measurements, atmospheric circulation and climate models. This research aims to improve the understanding of the optical and microphysical properties of different types of aerosols particles. Samples of volcanic ash, Saharan dust and other mineral aerosols particles were analyzed by different techniques. Ground samples were sieved down to 45um, de-agglomerated and resuspended in the laboratory using a Fluidized Bed Aerosol Generator (FBAG). Particles were collected on Nuclepore filters into PM10, PM2.5, or PM1.0. and analyzed by different techniques, such as Scanning Electron Microscopy (SEM) for determination of size distribution and shape, spectral reflectance for determination of the optical absorption properties as a function of the wavelength, material density, and X-Ray fluorescence for the elemental composition. The spectral imaginary part of refractive index from the UV to the short wave infrared (SWIR) wavelength was derived empirically from the measurements of the spectral mass absorption coefficient, size distribution and density of the material. Some selected samples were also analyzed with the Polarized Imaging Nephelometer (PI-Neph) instrument for the characterization of the aerosol polarized phase function. This work compares results of the spectral refractive index of different materials obtained by our methodology with those available in the literature. In some cases there are significant differences both in magnitude and spectral dependence of the imaginary refractive index. These differences are evaluated and discussed in this work.

  12. Prefrontal cortex activity during response selection predicts processing speed impairment in schizophrenia

    PubMed Central

    Woodward, Neil D.; Duffy-Alberto, Brittney; Karbasforoushan, Haleh

    2014-01-01

    Processing speed is the most impaired neuropsychological domain in schizophrenia and a robust predictor of functional outcome. Determining the specific cognitive operations underlying processing speed dysfunction and indentifying their neural correlates may assist in developing pro-cognitive interventions. Response selection, the process of mapping stimuli onto motor responses, correlates with neuropsychological tests of processing speed and may contribute to processing speed impairment in schizophrenia. This study investigated the relationship between behavioral and neural measures of response selection, and a neuropsychological index of processing speed in schizophrenia. 26 patients with schizophrenia and 21 healthy subjects underwent fMRI scanning during performance of 2 and 4-choice-reaction time (RT) tasks and completed the Wechsler Adult Intelligence Scale-III (WAIS) Processing Speed Index (PSI). Response selection, defined as RT slowing between 2 and 4-choice RT, was impaired in schizophrenia and correlated with psychometric processing speed. Greater activation of the dorsolateral prefrontal cortex (PFC) was observed in schizophrenia and correlated with poorer WAIS PSI scores. Deficient response selection and abnormal recruitment of the dorsolateral PFC during response selection contribute to processing speed impairment in schizophrenia. Interventions that improve response selection and normalize dorsolateral PFC function may improve processing speed in schizophrenia. PMID:23816240

  13. Work ability among nursing personnel in public hospitals and health centers in Campinas--Brazil.

    PubMed

    Monteiro, Inês; Chillida, Manuela de Santana Pi; Moreno, Luciana Contrera

    2012-01-01

    Nursing personnel is essential in hospital, health centers and enterprises and is the large work force in health system. A cross-sectional study was conducted in a large city in two public hospitals and five health centre with the objective of to evaluate the work ability and health aspects of nursing staff. The sample was composed by 570 workers. The Work Ability Index - WAI and a questionnaire with socio-demographic, health and life style data was applied. The majority of workers was women (83%), married (50.4%), and was working in night shift work (65.6%); 61.4% was auxiliary nursing, 22.3% was registered nurses (RN). The average age was 38.9 years (SD 7.8) and the Body Mass Index mean was 25.8 (SD 5.3). Only 17.2% referred to practice at least 150 minutes of physical exercise five times per week or more. 26.8% had a second job. The work ability mean was 39.3 (SD 5.3) points. Age had a negative correlation with WAI (p=0.0052). Public hospital and health centre workers had poor work ability score when compared with workers from another branches. Public policies related to workplace health promotion need to be implemented in public hospital and health centre to improve the work ability.

  14. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts.

    PubMed

    Chien, Chia-Chang; Huang, Shu-Fen; Lung, For-Wey

    2009-01-27

    The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts. We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) assessments. Logistic regression analysis showed the conceptual level responses (CLR) index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84). We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%. The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future.

  15. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts

    PubMed Central

    Chien, Chia-Chang; Huang, Shu-Fen; Lung, For-Wey

    2009-01-01

    Objective: The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts. Methods: We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) assessments. Results: Logistic regression analysis showed the conceptual level responses (CLR) index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84). We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%. Conclusion: The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future. PMID:21197345

  16. Understanding the absorption Angstrom exponent provided in the AERONET database

    NASA Astrophysics Data System (ADS)

    Schuster, G. L.; Dubovik, O.; Arola, A. T.

    2014-12-01

    Recently, some authors have suggested that the absorption Angstrom exponent (AAE) can be used to deduce the component aerosol absorption optical depths (AAOD) of dust, brown carbon, and soot carbon in the atmosphere. The premise behind this AAE approach is that AAE is a species-dependent aerosol property that does not depend upon particle size or mass, that absorbing aerosol species are externally mixed with one another, and that AAE is much less than 1 for black carbon. Other authors have found that AAE does not contain enough information to unambiguously speciate the absorbing aerosols. Thus, we explore this topic here, and point out some theoretical inconsistencies associated with using the AAE approach to deduce component AAODs from the AERONET retrievals. For instance, Level 2.0 retrievals at 15 West African sites subsampled for AAE < 1.0 indicate that 86% of the fine volume fractions are less than 0.2, 56% of the depolarization ratios are greater than 0.2, and 94% of the Angstrom exponents are less than 1.0. This indicates that most of the West African data with AAE < 1 are dominated by coarse mode dust, and that low AAE does not indicate pure BC, and that therefore AAE can not be used to separate carbonaceous aerosols from dust. We obtained similar results at five Middle East dust sites subsampled for AAE < 1.0, with 59% of the fine volume fractions less than 0.2, 88% of the depolarization ratios greater than 0.2, and 73% of the Angstrom exponents less than 1.0.Additionally, we find that AAE << 1 is very unlikely to occur for size distributions with fine volume fractions greater than 0.5 at nine southern Africa and South America sites, unless the imaginary refractive index at the 440 nm wavelength is less than the imaginary refractive index at the red and near infrared wavelengths (i.e., k(440) < k(rnir)). Since black carbon has a spectrally invariant imaginary refractive index at these wavelengths, it is unlikely to be the cause of k(440) < k(rnir) and AAE

  17. Achieving an Accurate Surface Profile of a Photonic Crystal for Near-Unity Solar Absorption in a Super Thin-Film Architecture.

    PubMed

    Kuang, Ping; Eyderman, Sergey; Hsieh, Mei-Li; Post, Anthony; John, Sajeev; Lin, Shawn-Yu

    2016-06-28

    In this work, a teepee-like photonic crystal (PC) structure on crystalline silicon (c-Si) is experimentally demonstrated, which fulfills two critical criteria in solar energy harvesting by (i) its Gaussian-type gradient-index profile for excellent antireflection and (ii) near-orthogonal energy flow and vortex-like field concentration via the parallel-to-interface refraction effect inside the structure for enhanced light trapping. For the PC structure on 500-μm-thick c-Si, the average reflection is only ∼0.7% for λ = 400-1000 nm. For the same structure on a much thinner c-Si ( t = 10 μm), the absorption is near unity (A ∼ 99%) for visible wavelengths, while the absorption in the weakly absorbing range (λ ∼ 1000 nm) is significantly increased to 79%, comparing to only 6% absorption for a 10-μm-thick planar c-Si. In addition, the average absorption (∼94.7%) of the PC structure on 10 μm c-Si for λ = 400-1000 nm is only ∼3.8% less than the average absorption (∼98.5%) of the PC structure on 500 μm c-Si, while the equivalent silicon solid content is reduced by 50 times. Furthermore, the angular dependence measurements show that the high absorption is sustained over a wide angle range (θinc = 0-60°) for teepee-like PC structure on both 500 and 10-μm-thick c-Si.

  18. Aerosol Absorption Measurements in MILAGRO.

    NASA Astrophysics Data System (ADS)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  19. TEMPO Specific Photochemical Reflectance Index for Monitoring Crop Productivity

    NASA Astrophysics Data System (ADS)

    Wulamu, A.; Fishman, J.; Maimaitiyiming, M.

    2016-12-01

    Chlorophyll fluorescence and Photochemical Reflectance Index (PRI) are two key indicators of plant functional status used for early stress detection. With its less than one nanometer hyperspectral resolution and hourly revisit capabilities, NASA's Tropospheric Emissions: Monitoring of Pollution (TEMPO) sensor provides new opportunities for monitoring regional food security. Chlorophyll fluorescence can be retrieved by TEMPO using Oxygen B (O2-B) absorption region at 687 nm. The Photochemical Reflectance Index (PRI) is calculated from spectral reflectance at 531 and 570. However, TEMPO spectral range covers from 290 mm - 490 nm and 540 nm -740 nm, does not provide the 531 nm measurement band for PRI. It is imperative to develop alternate wavelengths within the TEMPO spectral range for these early stress indicators so that regional crop health can be observed by TEMPO with unparalleled spectral and temporal resolutions to address food security. Combining field and airborne remote sensing experiments and radiative transfer simulations, this work proposes a TEMPO specific PRI and demonstrates that TEMPO offers a new set of high-resolution spectral data for crop monitoring.

  20. Quality of life, work ability and other important indicators of women's occupational health.

    PubMed

    Tavakoli-Fard, Negah; Mortazavi, Seyed-Alireza; Kuhpayehzadeh, Jalil; Nojomi, Marzieh

    2016-01-01

    Work ability may be considered as an important aspect of well-being and health status. One of the most important factors in association with work ability is health-related quality of life (HRQoL). The aim of this study has been to determine the association between work ability, individual characteristics and HRQoL of female workers. The design of this study has been cross-sectional. The work ability index (WAI) and Short-Form General Health Survey (SF-12) questionnaires were used to collect data. Three hundred and twenty female workers were selected from food supplier factories in Karaj. One-way analysis of variance, Pearson's correlation analysis, independent sample t-test and multiple linear regression methods were used to analyze data. Mean (M) and standard deviation (SD) of the WAI stood at 35.02 and 5.57, respectively. The categories of the WAI for women being as follows: 8.8% poor, 62% moderate, 25.4% good and 3.7% excellent. Mean±SD for the physical component summary (PCS) and mental component summary (MCS) of quality of life was 58.84±11.12 and 57.45±9.94, respectively. There was a positive significant association between the PCS and MCS with the WAI (p = 0.0001). Workers with higher education had a better work ability (p = 0.002) and shift-work workers had a worse work ability (p = 0.03). Work ability of majority of women was moderate. Considering mean age of studied women (27.6 years old), this work ability is not satisfactory. Physical and mental components of the HRQoL were the important factors associated with work ability. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  1. Clinical validity of the Japanese version of WAIS-III short forms: Adaptation for patients with mild neurocognitive disorder and dementia.

    PubMed

    Takeda, Mihoko; Nakaya, Makoto; Kikuchi, Yoko; Inoue, Sayaka; Kamata, Tomoyuki

    2018-01-01

    We investigated the Japanese WAIS-III short form utility in mild neurocognitive disorder and dementia. Our sample consisted of 108 old patients (ages: 65-89; mean age = 78.3). Fifteen short forms (SFs) and full-scale (FS) IQs were compared. The SFs included Dyads (SF1, SF2), Triads (SF3), Tetrads (SF4, SF5, SF6, SF7), Pentad (SF8), Six-subtest (SF9), Seven-subtests (SF10(a)(b), SF11(a)(b), SF12), and Nine-subtest (SF13). Correlations between SFIQs and FSIQ were all significant. Significant differences also were found in paired t-test between FSIQ and 5 SFIQs (SF2: t = -4.16, SF5: t = -7.06, SF7; t = 2.59, SF10(a): t = 2.56, SF12: t = -4.82; p < .05). On the point of clinical accuracy, two SFs led to an appropriate estimated IQ (SF11(a): 84.3%, SF13: 91.7%; within 95% confidence interval and 2 standard error of measurements of FSIQ). However, SF13 was considered to still have a long administration time. The present results suggest that SF11(a) could be the most useful to estimate IQ for Japanese speaking patients with mild neurocognitive disorder and dementia. SF11(a) consists of seven subtests of Similarities, Arithmetic, Digit Span, Information, Picture Completion, Digit Symbol-Coding, and Matrix Reasoning (Ryan & Ward, 1999), and the formula (Axelrod et al., 2001) should be adopted to convert scaled scores into estimated IQ scores. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. High-precision diode-laser-based temperature measurement for air refractive index compensation.

    PubMed

    Hieta, Tuomas; Merimaa, Mikko; Vainio, Markku; Seppä, Jeremias; Lassila, Antti

    2011-11-01

    We present a laser-based system to measure the refractive index of air over a long path length. In optical distance measurements, it is essential to know the refractive index of air with high accuracy. Commonly, the refractive index of air is calculated from the properties of the ambient air using either Ciddor or Edlén equations, where the dominant uncertainty component is in most cases the air temperature. The method developed in this work utilizes direct absorption spectroscopy of oxygen to measure the average temperature of air and of water vapor to measure relative humidity. The method allows measurement of temperature and humidity over the same beam path as in optical distance measurement, providing spatially well-matching data. Indoor and outdoor measurements demonstrate the effectiveness of the method. In particular, we demonstrate an effective compensation of the refractive index of air in an interferometric length measurement at a time-variant and spatially nonhomogeneous temperature over a long time period. Further, we were able to demonstrate 7 mK RMS noise over a 67 m path length using a 120 s sample time. To our knowledge, this is the best temperature precision reported for a spectroscopic temperature measurement. © 2011 Optical Society of America

  3. Association Among Sociodemograhic Factors, Work Ability, Health Behavior, and Mental Health Status for Young People After Prolonged Unemployment.

    PubMed

    Lappalainen, Kirsi; Manninen, Pirjo; Räsänen, Kimmo

    2017-02-01

    The purpose of this study was to explore the associations of prolonged unemployment, health, and work ability among young workers using data from the 2008-2010 Occupational Health Counselling project in Kuopio, Eastern Finland. The total sample for this study was 190 young unemployed adults. The questionnaire included the Work Ability Index (WAI), the Beck Depression Inventory, the Alcohol Use Disorders Identification Test, and the Occupational Health Counselling Survey. Multivariate analyses revealed that men had a higher prevalence of prolonged unemployment than women. Using drugs for purposes other than treatment was associated independently with an increased prevalence of prolonged unemployment. Low WAI scores were associated with a higher prevalence of prolonged unemployment. This study showed that attention should be paid to male workers, those who have poor or moderate work ability and workers who use drugs. Young unemployed workers should be recognized at an early stage. A comprehensive, flexible network of community resources is essential to support young unemployed adults.

  4. Characterization of ion-assisted induced absorption in A-Si thin-films used for multivariate optical computing

    NASA Astrophysics Data System (ADS)

    Nayak, Aditya B.; Price, James M.; Dai, Bin; Perkins, David; Chen, Ding Ding; Jones, Christopher M.

    2015-06-01

    Multivariate optical computing (MOC), an optical sensing technique for analog calculation, allows direct and robust measurement of chemical and physical properties of complex fluid samples in high-pressure/high-temperature (HP/HT) downhole environments. The core of this MOC technology is the integrated computational element (ICE), an optical element with a wavelength-dependent transmission spectrum designed to allow the detector to respond sensitively and specifically to the analytes of interest. A key differentiator of this technology is it uses all of the information present in the broadband optical spectrum to determine the proportion of the analyte present in a complex fluid mixture. The detection methodology is photometric in nature; therefore, this technology does not require a spectrometer to measure and record a spectrum or a computer to perform calculations on the recorded optical spectrum. The integrated computational element is a thin-film optical element with a specific optical response function designed for each analyte. The optical response function is achieved by fabricating alternating layers of high-index (a-Si) and low-index (SiO2) thin films onto a transparent substrate (BK7 glass) using traditional thin-film manufacturing processes (e.g., ion-assisted e-beam vacuum deposition). A proprietary software and process are used to control the thickness and material properties, including the optical constants of the materials during deposition to achieve the desired optical response function. The ion-assisted deposition is useful for controlling the densification of the film, stoichiometry, and material optical constants as well as to achieve high deposition growth rates and moisture-stable films. However, the ion-source can induce undesirable absorption in the film; and subsequently, modify the optical constants of the material during the ramp-up and stabilization period of the e-gun and ion-source, respectively. This paper characterizes the unwanted

  5. High index glass thin film processing for photonics and photovoltaic (PV) applications

    NASA Astrophysics Data System (ADS)

    Ogbuu, Okechukwu Anthony

    To favorably compete with fossil-fuel technology, the greatest challenge for thin film solar-cells is to improve efficiency and reduce material cost. Thickness scaling to thin film reduces material cost but affects the light absorption in the cells; therefore a concept that traps incident photons and increases its optical path length is needed to boost absorption in thin film solar cells. One approach is the integration of low symmetric gratings (LSG), using high index material, on either the front-side or backside of 30 um thin c-Si cells. In this study, Multicomponent TeO2--Bi2O 3--ZnO (TBZ) glass thin films were prepared using RF magnetron sputtering under different oxygen flow rates. The influences of oxygen flow rate on the structural and optical properties of the resulting thin films were investigated. The structural origin of the optical property variation was studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman Spectroscopy, and transmission electron microscopy. The results indicate that TBZ glass thin film is a suitable material for front side LSG material photovoltaic and photonics applications due to their amorphous nature, high refractive index (n > 2), broad band optical transparency window, low processing temperature. We developed a simple maskless method to pattern sputtered tellurite based glass thin films using unconventional agarose hydrogel mediated wet etching. Conventional wet etching process, while claiming low cost and high throughput, suffers from reproducibility and pattern fidelity issues due to the isotropic nature of wet chemical etching when applied to glasses and polymers. This method overcomes these challenges by using an agarose hydrogel stamp to mediate a conformal etching process. In our maskless method, agarose hydrogel stamps are patterned following a standard soft lithography and replica molding process from micropatterned masters and soaked in a chemical etchant. The micro-scale features on the stamp are

  6. Satellite-Based Evidence of Wavelength-Dependent Aerosol Absorption in Biomass Burning Smoke Inferred from Ozone Monitoring Instrument

    NASA Technical Reports Server (NTRS)

    Jethva, H.; Torres, O.

    2012-01-01

    We provide satellite-based evidence of the spectral dependence of absorption in biomass burning aerosols over South America using near-UV measurements made by the Ozone Monitoring Instrument (OMI) during 2005-2007. In the current near-UV OMI aerosol algorithm (OMAERUV), it is implicitly assumed that the only absorbing component in carbonaceous aerosols is black carbon whose imaginary component of the refractive index is wavelength independent. With this assumption, OMI-derived aerosol optical depth (AOD) is found to be significantly over-estimated compared to that of AERONET at several sites during intense biomass burning events (August-September). Other well-known sources of error affecting the near-UV method of aerosol retrieval do not explain the large observed AOD discrepancies between the satellite and the ground-based observations. A number of studies have revealed strong spectral dependence in carbonaceous aerosol absorption in the near-UV region suggesting the presence of organic carbon in biomass burning generated aerosols. A sensitivity analysis examining the importance of accounting for the presence of wavelength-dependent aerosol absorption in carbonaceous particles in satellite-based remote sensing was carried out in this work. The results convincingly show that the inclusion of spectrally-dependent aerosol absorption in the radiative transfer calculations leads to a more accurate characterization of the atmospheric load of carbonaceous aerosols.

  7. Snow Accumulation Variability Over the West Antarctic Ice Sheet Since 1900: A Comparison of Ice Core Records With ERA-20C Reanalysis

    NASA Astrophysics Data System (ADS)

    Wang, Yetang; Thomas, Elizabeth R.; Hou, Shugui; Huai, Baojuan; Wu, Shuangye; Sun, Weijun; Qi, Shanzhong; Ding, Minghu; Zhang, Yulun

    2017-11-01

    This study uses a set of 37 firn core records over the West Antarctic Ice Sheet (WAIS) to test the performance of the twentieth century from the European Centre for Medium-Range Weather Forecasts (ERA-20C) reanalysis for snow accumulation and quantify temporal variability in snow accumulation since 1900. The firn cores are allocated to four geographical areas demarcated by drainage divides (i.e., Antarctic Peninsula (AP), western WAIS, central WAIS, and eastern WAIS) to calculate stacked records of regional snow accumulation. Our results show that the interannual variability in ERA-20C precipitation minus evaporation (P - E) agrees well with the corresponding ice core snow accumulation composites in each of the four geographical regions, suggesting its skill for simulating snow accumulation changes before the modern satellite era (pre-1979). Snow accumulation experiences significantly positive trends for the AP and eastern WAIS, a negative trend for the western WAIS, and no significant trend for the central WAIS from 1900 to 2010. The contrasting trends are associated with changes in the large-scale moisture transport driven by a deepening of the low-pressure systems and anomalies of sea ice in the Amundsen Sea Low region.

  8. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R [Albuquerque, NM; Reed, Scott T [Albuquerque, NM; Ashley, Carol S [Albuquerque, NM; Martinez, F Edward [Horseheads, NY

    2004-08-31

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  9. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R [Albuquerque, NM; Reed, Scott T [Albuquerque, NM; Ashley, Carol S [Albuquerque, NM; Martinez, F Edward [Horseheads, NY

    2003-10-14

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  10. Lasing characteristics of refractive-index-matched composite Y3Al5O12 rods employing transparent ceramics for solar-pumped lasers

    NASA Astrophysics Data System (ADS)

    Hasegawa, Kazuo; Ichikawa, Tadashi; Takeda, Yasuhiko; Ikesue, Akio; Ito, Hiroshi; Motohiro, Tomoyoshi

    2018-04-01

    We have proposed a new configuration of solar-pumped lasers employing transparent ceramic rods. The laser rod has a composite structure consisting of a Nd/Cr:YAG gain domain surrounded by Gd:YAG with the same refractive index as that of Nd/Cr:YAG. The lasing mode is well controlled by the output coupler, and the parasitic oscillation is suppressed, owing to the refractive index matching. A high laser slope efficiency and a low laser oscillation threshold were achieved owing to the suppressed absorption outside the lasing mode, which was previously a serious issue for the end-pumping configuration using a high-NA focusing optics. The laser oscillation threshold of 136 mW and the slope efficiency of 25.3% were derived. Thus, we have resolved the issue of useless absorption associated with the high-NA end-pumping, and achieved significant improvements compared with the conventional structure of uniform Nd/Cr:YAG.

  11. Polyamidoamine dendrimers as novel potential absorption enhancers for improving the small intestinal absorption of poorly absorbable drugs in rats.

    PubMed

    Lin, Yulian; Fujimori, Takeo; Kawaguchi, Naoko; Tsujimoto, Yuiko; Nishimi, Mariko; Dong, Zhengqi; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2011-01-05

    Effects of polyamidoamine (PAMAM) dendrimers on the intestinal absorption of poorly absorbable drugs were examined by an in situ closed loop method in rats. 5(6)-Carboxyfluorescein (CF), fluorescein isothiocyanate-dextrans (FDs) with various molecular weights, calcitonin and insulin were used as model drugs of poorly absorbable drugs. The absorption of CF, FD4 and calcitonin from the rat small intestine was significantly enhanced in the presence of PAMAM dendrimers. The absorption-enhancing effects of PAMAM dendrimers for improving the small intestinal absorption of CF were concentration and generation dependent and a maximal absorption-enhancing effect was observed in the presence of 0.5% (w/v) G2 PAMAM dendrimer. However, G2 PAMAM dendrimer had almost no absorption-enhancing effect on the small intestinal absorption of macromolecular drugs including FD10 and insulin. Overall, the absorption-enhancing effects of G2 PAMAM dendrimer in the small intestine decreased as the molecular weights of drug increased. However, G2 PAMAM dendrimer did not enhance the intestinal absorption of these drugs with different molecular weights in the large intestine. Furthermore, we evaluated the intestinal membrane damage with or without G2 PAMAM dendrimer. G2 PAMAM dendrimer (0.5% (w/v)) significantly increased the activities of lactate dehydrogenase (LDH) and the amounts of protein released from the intestinal membranes, but the activities and amounts of these toxic markers were less than those in the presence of 3% Triton X-100 used as a positive control. Moreover, G2 PAMAM dendrimer at concentrations of 0.05% (w/v) and 0.1% (w/v) did not increase the activities and amounts of these toxic markers. These findings suggested that PAMAM dendrimers at lower concentrations might be potential and safe absorption enhancers for improving absorption of poorly absorbable drugs from the small intestine. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Food Ingredients That Inhibit Cholesterol Absorption

    PubMed Central

    Jesch, Elliot D.; Carr, Timothy P.

    2017-01-01

    Cholesterol is a vital component of the human body. It stabilizes cell membranes and is the precursor of bile acids, vitamin D and steroid hormones. However, cholesterol accumulation in the bloodstream (hypercholesterolemia) can cause atherosclerotic plaques within artery walls, leading to heart attacks and strokes. The efficiency of cholesterol absorption in the small intestine is of great interest because human and animal studies have linked cholesterol absorption with plasma concentration of total and low density lipoprotein cholesterol. Cholesterol absorption is highly regulated and influenced by particular compounds in the food supply. Therefore, it is desirable to learn more about natural food components that inhibit cholesterol absorption so that food ingredients and dietary supplements can be developed for consumers who wish to manage their plasma cholesterol levels by non-pharmacological means. Food components thus far identified as inhibitors of cholesterol absorption include phytosterols, soluble fibers, phospholipids, and stearic acid. PMID:28702423

  13. Photoionization-driven Absorption-line Variability in Balmer Absorption Line Quasar LBQS 1206+1052

    NASA Astrophysics Data System (ADS)

    Sun, Luming; Zhou, Hongyan; Ji, Tuo; Jiang, Peng; Liu, Bo; Liu, Wenjuan; Pan, Xiang; Shi, Xiheng; Wang, Jianguo; Wang, Tinggui; Yang, Chenwei; Zhang, Shaohua; Miller, Lauren P.

    2017-04-01

    In this paper we present an analysis of absorption-line variability in mini-BAL quasar LBQS 1206+1052. The Sloan Digital Sky Survey spectrum demonstrates that the absorption troughs can be divided into two components of blueshift velocities of ˜700 and ˜1400 km s-1 relative to the quasar rest frame. The former component shows rare Balmer absorption, which is an indicator of high-density absorbing gas; thus, the quasar is worth follow-up spectroscopic observations. Our follow-up optical and near-infrared spectra using MMT, YFOSC, TSpec, and DBSP reveal that the strengths of the absorption lines vary for both components, while the velocities do not change. We reproduce all of the spectral data by assuming that only the ionization state of the absorbing gas is variable and that all other physical properties are invariable. The variation of ionization is consistent with the variation of optical continuum from the V-band light curve. Additionally, we cannot interpret the data by assuming that the variability is due to a movement of the absorbing gas. Therefore, our analysis strongly indicates that the absorption-line variability in LBQS 1206+1052 is photoionization driven. As shown from photoionization simulations, the absorbing gas with blueshift velocity of ˜700 km s-1 has a density in the range of 109 to 1010 cm-3 and a distance of ˜1 pc, and the gas with blueshift velocity of ˜1400 km s-1 has a density of 103 cm-3 and a distance of ˜1 kpc.

  14. Laser Atmospheric Absorption Studies.

    DTIC Science & Technology

    1977-05-01

    A. Modification of Commercial C09 Laser 50 B. CW HF/DF Laser System * 53 C. Microcomputer Data Link 55 D . Fourier Transform...improved accuracy are used [5]. c. The absorption coefficient is listed for each absorbing species separately which some codes require. d . A super...series of water vapor absorption measurements was planned. The results of the first four lines studied are presented here in Figures 33a- d . Figure

  15. A Hot Gaseous Galaxy Halo Candidate with Mg X Absorption

    NASA Astrophysics Data System (ADS)

    Qu, Zhijie; Bregman, Joel N.

    2016-12-01

    The hot gas in galaxy halos may account for a significant fraction of missing baryons in galaxies, and some of these gases can be traced by high ionization absorption systems in QSO UV spectra. Using high S/N Hubble Space Telescope/Cosmic Origins Spectrograph spectra, we discovered a high ionization state system at z = 1.1912 in the sightline toward LBQS 1435-0134, and two-component absorption lines are matched for Mg x, Ne viii, Ne VI, O VI, Ne v, O v, Ne IV, O IV, N IV, O III, and H I. Mg x, detected for the first time (5.8σ), is a particularly direct tracer of hot galactic halos, as its peak ion fraction occurs near 106.1 K, about the temperature of a virialized hot galaxy halo of mass ˜ 0.5{M}* . With Mg x and Ne viii, a photoionization model cannot reproduce the observed column densities with path lengths of galaxy halos. For collisional ionization models, one or two-temperature models do not produce acceptable fits, but a three-temperature model or a power-law model can produce the observed results. In the power-law model, {dN}/{dT}={10}4.4+/- 2.2-[Z/X]{T}1.55+/- 0.41 with temperatures in the range of {10}4.39+/- 0.13 {{K}}\\lt T\\lt {10}6.04+/- 0.05 {{K}}, the total hydrogen column density is 8.2× {10}19(0.3 {Z}⊙ /Z) {{cm}}-2 and the positive power-law index indicates most of the mass is at the high temperature end. We suggest that this absorption system is a hot volume-filled galaxy halo rather than interaction layers between the hot halo and cool clouds. The temperature dependence of the column density is likely due to the local mixture of multiple phase gases.

  16. Ammonia and ammonium hydroxide sensors for ammonia/water absorption machines: Literature review and data compilation

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

    Anheier, N.C. Jr.; McDonald, C.E.; Cuta, J.M.

    1995-05-01

    This report describes an evaluation of various sensing techniques for determining the ammonia concentration in the working fluid of ammonia/water absorption cycle systems. The purpose of this work was to determine if any existing sensor technology or instrumentation could provide an accurate, reliable, and cost-effective continuous measure of ammonia concentration in water. The resulting information will be used for design optimization and cycle control in an ammonia-absorption heat pump. PNL researchers evaluated each sensing technology against a set of general requirements characterizing the potential operating conditions within the absorption cycle. The criteria included the physical constraints for in situ operation,more » sensor characteristics, and sensor application. PNL performed an extensive literature search, which uncovered several promising sensing technologies that might be applicable to this problem. Sixty-two references were investigated, and 33 commercial vendors were identified as having ammonia sensors. The technologies for ammonia sensing are acoustic wave, refractive index, electrode, thermal, ion-selective field-effect transistor (ISFET), electrical conductivity, pH/colormetric, and optical absorption. Based on information acquired in the literature search, PNL recommends that follow-on activities focus on ISFET devices and a fiber optic evanescent sensor with a colormetric indicator. The ISFET and fiber optic evanescent sensor are inherently microminiature and capable of in situ measurements. Further, both techniques have been demonstrated selective to the ammonium ion (NH{sub 4}{sup +}). The primary issue remaining is how to make the sensors sufficiently corrosion-resistant to be useful in practice.« less

  17. High-Absorptance Radiative Heat Sink

    NASA Technical Reports Server (NTRS)

    Cafferty, T.

    1983-01-01

    Absorptance of black-painted open-cell aluminum honeycomb improved by cutting honeycomb at angle or bias rather than straight across. This ensures honeycomb cavities escapes. At each reflection radiation attenuated by absorption. Applications include space-background simulators, space radiators, solar absorbers, and passive coolers for terrestrial use.

  18. Absorption Coefficient of Alkaline Earth Halides.

    DTIC Science & Technology

    1980-04-01

    not observed at low energy level , are developed at high power levels . No matter how low the absorption is. the effect is objectionable at high-energy... levels . As a natural consequence, the magnitude of the absorption coefficient is the key parameter in selecting laser window materials. Over the past...Presence of impurities can complicate the exponential tail. particularly at low absorption levels . The impurities may enter 12 the lattice singly or

  19. Water absorption characteristic of interlocking compressed earth brick units

    NASA Astrophysics Data System (ADS)

    Bakar, B. H. Abu; Saari, S.; Surip, N. A.

    2017-10-01

    This study aims to investigate the water absorption characteristic of interlocking compressed earth brick (ICEB) units. Apart from compressive strength, water absorption is an important property in masonry. This property can affect the quality of the brick itself and the bond strength between the brick and mortar in masonry structures and can result in reducing its strength properties. The units were tested for 24 h water absorption and 5 h boiling water absorption. A total of 170 ICEB units from four ICEB types underwent both tests. For the 24 h water absorption, the ICEB units were dried in the oven for 24 h and then cooled before being weighed. Thereafter, each brick was immersed in water for 24 h and weighed. The same specimens used for the 24 h water absorption test were re-used for the 5 h boiling water absorption test. After completing the 24 h water absorption test, the brick was boiled for 5-hours and weighed. The highest water absorption for the ICEBs in the 24-hour water absorption and 5 h boiling water absorption tests are 15.09% and 17.18%, respectively. The half brick has the highest water absorption (15.87%), whereas the beam brick has the lowest (13.20%). The water absorption of an ICEB unit is higher than that of normal bricks, although the water absorption of the former remains below the maximum rate of the brick water absorption (21%).

  20. The saturable absorption and reverse saturable absorption properties of Cu doped zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Yao, Cheng-Bao; Wen, Xin; Li, Qiang-Hua; Yan, Xiao-Yan; Li, Jin; Zhang, Ke-Xin; Sun, Wen-Jun; Bai, Li-Na; Yang, Shou-Bin

    2017-03-01

    We present the structure and nonlinear absorption (NLA) properties of Cu-doped ZnO (CZO) films prepared by magnetron sputtering. The films were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results show that the CZO films can maintain a wurtzite structure. Furthermore, the open-aperture (OA) Z-scan measurements of the film were carried out by nanosecond laser pulse. A transition from saturable absorption (SA) to reverse saturable absorption (RSA) was observed as the excitation intensity increasing. With good excellent nonlinear optical coefficient, the samples were expected to be the potential applications in optical devices.

  1. Consumer acceptability of gluten-free cookies containing raw cooked and germinated pinto bean flours.

    PubMed

    Simons, Courtney Wayne; Hall, Clifford

    2018-01-01

    Beany and grassy flavors in raw edible bean flours reduce consumer acceptability of bean-based baked products. In order to improve consumer acceptability, beans may be further processed by cooking and germination. However, these operations drive up the cost of end-products. Therefore, it is necessary to develop formulations, using raw edible bean flours that have acceptable sensory attributes. In this study, cooked, germinated, and germinated/steam-blanched (GSB) pinto bean flours were used to make gluten-free cookies, and their sensory characteristics evaluated to determine how their consumer acceptability scores compared. Taste panelists (31) graded cookies made from raw pinto beans with an overall value of 6 on a 9-point hedonic scale ( p  < .05). This rating was not significantly different from cookies formulated with germinated and GSB flours. Therefore, gluten-free cookies can be made using raw pinto bean flours at a 40% inclusion level, with similar sensory characteristics as those prepared with flours treated by cooking and germination. Instrumental measurement of cookie hardness and color showed no significant difference in hardness, but significant differences in color. The germinated bean flour produced cookies with a significantly lower L* value and significantly higher a*, b*, Chroma and hue values compared to the other treatments. There was no significant difference in the cookie spread ratio. Proximate composition, water absorption index (WAI), water solubility index (WSI) and gelatinization properties of the flour treatments were characterized.

  2. Index-antiguided planar waveguide lasers with large mode area

    NASA Astrophysics Data System (ADS)

    Liu, Yuanye

    The on-going research and application interests with high power large-mode-area (LMA) waveguide lasers, especially in fiber geometry, at the beginning of this century drive the development of many novel waveguide designs. Index antiguiding, proposed by Siegman in 2003, is among one of them. The goal for index antiguiding is to introduce transversal modal loss with the relative simple waveguide design while maintain single transverse mode operation for good beam quality. The idea which is selectively support of fundamental mode is facilitated by involving certain level of signal regeneration inside the waveguide core. Since the modal loss is closed associated with waveguide design parameters such as core size and refractive index, the amount of gain inside the core provides active control of transverse modes inside index-antiguiding waveguide. For example, fundamental transverse mode inside such waveguide can be excited and propagate lossless when sufficient optical gain is provided. This often requires doped waveguide core and optical pumping at corresponding absorption band. However, the involvement of optical pumping also has its consequences. Phenomena such as thermal-optic effect and gain spatial hole-burning which are commonly found in bulk lasers request attention when scaling up output power with LMA index-antiguided waveguide amplifiers and resonators. In response, three key challenges of index-antiguided planar waveguide lasers, namely, guiding mechanism, power efficiency and transverse mode discrimination, are analyzed theoretically and experimentally in this dissertation. Experiments are based on two index-antiguided planar waveguide chips, whose core thickness are 220 microm and 400 microm respectively. The material of waveguide core is 1% Neodymium-doped Yttrium Aluminium garnet, or Nd:YAG while the cladding is made from Terbium Gallium garnet, or TGG. Due to the face pumping and limited pump power, it is found, with 220 microm-thick-core chip, that

  3. Discovery of Hα Absorption in the Unusual Broad Absorption Line Quasar SDSS J083942.11+380526.3

    NASA Astrophysics Data System (ADS)

    Aoki, Kentaro; Iwata, Ikuru; Ohta, Kouji; Ando, Masataka; Akiyama, Masayuki; Tamura, Naoyuki

    2006-11-01

    We discovered Hα absorption in the broad Hα emission line of an unusual broad absorption line quasar, SDSS J083942.11+380526.3, at z=2.318, through near-infrared spectroscopy with the Cooled Infrared Spectrograph and Camera for OHS (CISCO) on the Subaru telescope. The presence of nonstellar Hα absorption is known only in the Seyfert galaxy NGC 4151 to date; thus, our discovery is the first case for quasars. The Hα absorption line is blueshifted by 520 km s-1 relative to the Hα emission line, and its redshift almost coincides with those of UV low-ionization metal absorption lines. The width of the Hα absorption (~340 km s-1) is similar to those of the UV low-ionization absorption lines. These facts suggest that the Hα and low-ionization metal absorption lines are produced by the same low-ionization gas, which has a substantial amount of neutral gas. The column density of the neutral hydrogen is estimated to be ~1018 cm-2 by assuming a gas temperature of 10,000 K from the analysis of the curve of growth. The continuum spectrum is reproduced by a reddened [E(B-V)~0.15 mag for the SMC-like reddening law] composite quasar spectrum. Furthermore, the UV spectrum of SDSS J083942.11+380526.3 shows a remarkable similarity to that of NGC 4151 in its low state, suggesting that the physical condition of the absorber in SDSS J083942.11+380526.3 is similar to that of NGC 4151 in the low state. As proposed for NGC 4151, SDSS J083942.11+380526.3 may also be seen through the edge of the obscuring torus. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  4. The effect of volatility on percutaneous absorption.

    PubMed

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  5. Photoionization-driven Absorption-line Variability in Balmer Absorption Line Quasar LBQS 1206+1052

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

    Sun, Luming; Zhou, Hongyan; Ji, Tuo

    In this paper we present an analysis of absorption-line variability in mini-BAL quasar LBQS 1206+1052. The Sloan Digital Sky Survey spectrum demonstrates that the absorption troughs can be divided into two components of blueshift velocities of ∼700 and ∼1400 km s{sup −1} relative to the quasar rest frame. The former component shows rare Balmer absorption, which is an indicator of high-density absorbing gas; thus, the quasar is worth follow-up spectroscopic observations. Our follow-up optical and near-infrared spectra using MMT, YFOSC, TSpec, and DBSP reveal that the strengths of the absorption lines vary for both components, while the velocities do notmore » change. We reproduce all of the spectral data by assuming that only the ionization state of the absorbing gas is variable and that all other physical properties are invariable. The variation of ionization is consistent with the variation of optical continuum from the V -band light curve. Additionally, we cannot interpret the data by assuming that the variability is due to a movement of the absorbing gas. Therefore, our analysis strongly indicates that the absorption-line variability in LBQS 1206+1052 is photoionization driven. As shown from photoionization simulations, the absorbing gas with blueshift velocity of ∼700 km s{sup −1} has a density in the range of 10{sup 9} to 10{sup 10} cm{sup −3} and a distance of ∼1 pc, and the gas with blueshift velocity of ∼1400 km s{sup −1} has a density of 10{sup 3} cm{sup −3} and a distance of ∼1 kpc.« less

  6. On pulsating cosmic /radio/ noise absorption

    NASA Technical Reports Server (NTRS)

    Dangelo, N.

    1981-01-01

    It has been proposed that some absorption events measured on riometers are actually due to backscatter of cosmic radio noise by E-region plasma waves (D'Angelo, 1976, 1978; D'Angelo and Mehta, 1980). Assuming that DC or nearly DC absorption is a viable process, it is shown that it may also be operative in producing pulsations in cosmic noise absorption on riometers, with periods ranging from a few seconds to several minutes.

  7. Absorption enhancement in non-coplanar silver nanowire networks

    NASA Astrophysics Data System (ADS)

    He, Zhihui; Zhou, Zhiping; Ren, Xincheng; Bai, Shaomin; Li, Hongjian; Cao, Dongmei; Li, Gang; Cao, Guangtao

    2018-07-01

    We propose non-coplanar silver nanowire (AgNW) networks placed on a SiO2 layer. A notable absorption peak is observed in our proposed structure, and compared with the absorption of coplanar periodic AgNW networks and periodic AgNW gratings, the absorption performance of the non-coplanar AgNW networks demonstrates obvious advantages. It could be determined that the absorption ratio in this non-coplanar AgNW networks can reach 95%. In addition, several parameters that have important effects on the absorption of the non-coplanar AgNW networks are discussed in detail. Our research may provide guidance for the fundamental exploration of plasmonic absorption device applications.

  8. Importance of the green color, absorption gradient, and spectral absorption of chloroplasts for the radiative energy balance of leaves.

    PubMed

    Kume, Atsushi

    2017-05-01

    Terrestrial green plants absorb photosynthetically active radiation (PAR; 400-700 nm) but do not absorb photons evenly across the PAR waveband. The spectral absorbance of photosystems and chloroplasts is lowest for green light, which occurs within the highest irradiance waveband of direct solar radiation. We demonstrate a close relationship between this phenomenon and the safe and efficient utilization of direct solar radiation in simple biophysiological models. The effects of spectral absorptance on the photon and irradiance absorption processes are evaluated using the spectra of direct and diffuse solar radiation. The radiation absorption of a leaf arises as a consequence of the absorption of chloroplasts. The photon absorption of chloroplasts is strongly dependent on the distribution of pigment concentrations and their absorbance spectra. While chloroplast movements in response to light are important mechanisms controlling PAR absorption, they are not effective for green light because chloroplasts have the lowest spectral absorptance in the waveband. With the development of palisade tissue, the incident photons per total palisade cell surface area and the absorbed photons per chloroplast decrease. The spectral absorbance of carotenoids is effective in eliminating shortwave PAR (<520 nm), which contains much of the surplus energy that is not used for photosynthesis and is dissipated as heat. The PAR absorptance of a whole leaf shows no substantial difference based on the spectra of direct or diffuse solar radiation. However, most of the near infrared radiation is unabsorbed and heat stress is greatly reduced. The incident solar radiation is too strong to be utilized for photosynthesis under the current CO 2 concentration in the terrestrial environment. Therefore, the photon absorption of a whole leaf is efficiently regulated by photosynthetic pigments with low spectral absorptance in the highest irradiance waveband and through a combination of pigment density

  9. Split-flow regeneration in absorptive air separation

    DOEpatents

    Weimer, Robert F.

    1987-01-01

    A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs.

  10. Atmospheric absorption of sound - Update

    NASA Technical Reports Server (NTRS)

    Bass, H. E.; Sutherland, L. C.; Zuckerwar, A. J.

    1990-01-01

    Best current expressions for the vibrational relaxation times of oxygen and nitrogen in the atmosphere are used to compute total absorption. The resulting graphs of total absorption as a function of frequency for different humidities should be used in lieu of the graph published earlier by Evans et al (1972).

  11. Dilution cycle control for an absorption refrigeration system

    DOEpatents

    Reimann, Robert C.

    1984-01-01

    A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

  12. Dissociative absorption: An empirically unique, clinically relevant, dissociative factor.

    PubMed

    Soffer-Dudek, Nirit; Lassri, Dana; Soffer-Dudek, Nir; Shahar, Golan

    2015-11-01

    Research of dissociative absorption has raised two questions: (a) Is absorption a unique dissociative factor within a three-factor structure, or a part of one general dissociative factor? Even when three factors are found, the specificity of the absorption factor is questionable. (b) Is absorption implicated in psychopathology? Although commonly viewed as "non-clinical" dissociation, absorption was recently hypothesized to be specifically associated with obsessive-compulsive symptoms. To address these questions, we conducted exploratory and confirmatory factor analyses on 679 undergraduates. Analyses supported the three-factor model, and a "purified" absorption scale was extracted from the original inclusive absorption factor. The purified scale predicted several psychopathology scales. As hypothesized, absorption was a stronger predictor of obsessive-compulsive symptoms than of general psychopathology. In addition, absorption was the only dissociative scale that longitudinally predicted obsessive-compulsive symptoms. We conclude that absorption is a unique and clinically relevant dissociative tendency that is particularly meaningful to obsessive-compulsive symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Absorption characteristics of forest fire particulate matter

    Treesearch

    E.M. Patterson; Charles K. McMahon

    1984-01-01

    Abstract. Absorption properties of smokes from laboratory fires that represent prescription hums in the Southern states have been quantified to relate variations in measured absorption parameters to variation in fire conditions and to estimate emission factors for elemental carbon. Results showed significant differences in absorption of the smoke...

  14. Split-flow regeneration in absorptive air separation

    DOEpatents

    Weimer, R.F.

    1987-11-24

    A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.

  15. Refractive index of solutions of human hemoglobin from the near-infrared to the ultraviolet range: Kramers-Kronig analysis.

    PubMed

    Sydoruk, Oleksiy; Zhernovaya, Olga; Tuchin, Valery; Douplik, Alexandre

    2012-11-01

    Because direct measurements of the refractive index of hemoglobin over a large wavelength range are challenging, indirect methods deserve particular attention. Among them, the Kramers-Kronig relations are a powerful tool often used to derive the real part of a refractive index from its imaginary part. However, previous attempts to apply the relations to solutions of human hemoglobin have been somewhat controversial, resulting in disagreement between several studies. We show that this controversy can be resolved when careful attention is paid not only to the absorption of hemoglobin but also to the dispersion of the refractive index of the nonabsorbing solvent. We present a Kramers-Kroning analysis taking both contributions into account and compare the results with the data from several studies. Good agreement with experiments is found across the visible and parts of near-infrared and ultraviolet regions. These results reinstate the use of the Kramers-Kronig relations for hemoglobin solutions and provide an additional source of information about their refractive index.

  16. Giant Gating Tunability of Optical Refractive Index in Transition Metal Dichalcogenide Monolayers.

    PubMed

    Yu, Yiling; Yu, Yifei; Huang, Lujun; Peng, Haowei; Xiong, Liwei; Cao, Linyou

    2017-06-14

    We report that the refractive index of transition metal dichacolgenide (TMDC) monolayers, such as MoS 2 , WS 2 , and WSe 2 , can be substantially tuned by >60% in the imaginary part and >20% in the real part around exciton resonances using complementary metal-oxide-semiconductor (CMOS) compatible electrical gating. This giant tunablility is rooted in the dominance of excitonic effects in the refractive index of the monolayers and the strong susceptibility of the excitons to the influence of injected charge carriers. The tunability mainly results from the effects of injected charge carriers to broaden the spectral width of excitonic interband transitions and to facilitate the interconversion of neutral and charged excitons. The other effects of the injected charge carriers, such as renormalizing bandgap and changing exciton binding energy, only play negligible roles. We also demonstrate that the atomically thin monolayers, when combined with photonic structures, can enable the efficiencies of optical absorption (reflection) tuned from 40% (60%) to 80% (20%) due to the giant tunability of the refractive index. This work may pave the way toward the development of field-effect photonics in which the optical functionality can be controlled with CMOS circuits.

  17. Bicarbonate absorption stimulates active calcium absorption in the rat proximal tubule.

    PubMed Central

    Bomsztyk, K; Calalb, M B

    1988-01-01

    To evaluate the effect of luminal bicarbonate on calcium reabsorption, rat proximal tubules were perfused in vivo. Perfusion solution contained mannitol to reduce water flux to zero. Total Ca concentration was measured by atomic absorption spectrometry, Ca ion concentration in the tubule lumen (CaL2+) and the peritubular capillary (CaP2+), and luminal pH (pHL) with ion-selective microelectrodes and transepithelial voltage (VTE) with conventional microelectrodes. When tubules were perfused with buffer-free Cl-containing solution, net Ca absorption (JCa) averaged 3.33 pmol/min. Even though VTE was 1.64 mV lumen-positive, CaL2+, 1.05 mM, did not fall below the concentration in the capillary blood, 1.07 mM. When 27 mM of Cl was replaced with HCO3, there was luminal fluid acidification. Despite a decrease in VTE and CaL2+, JCa increased to 7.13 pmol/min, indicating that the enhanced JCa could not be accounted for by the reduced electrochemical gradient, delta CCa. When acetazolamide or an analogue of amiloride was added to the HCO3 solution, JCa was not different from the buffer-free solution, suggesting that HCO3-stimulated JCa may be linked to acidification. To further test this hypothesis, we used 27 mM Hepes as the luminal buffer. With Hepes there was luminal fluid acidification and JCa was not different from the buffer-free solution but delta CCa was significantly reduced, indicating enhanced active calcium transport. We conclude from the results of the present study that HCO3 stimulates active Ca absorption, a process that may be linked to acidification-mediated HCO3 absorption. PMID:3366902

  18. Mapping the availability and accessibility of healthy food in rural and urban New Zealand--Te Wai o Rona: Diabetes Prevention Strategy.

    PubMed

    Wang, Jing; Williams, Margaret; Rush, Elaine; Crook, Nic; Forouhi, Nita G; Simmons, David

    2010-07-01

    Uptake of advice for lifestyle change for obesity and diabetes prevention requires access to affordable 'healthy' foods (high in fibre/low in sugar and fat). The present study aimed to examine the availability and accessibility of 'healthy' foods in rural and urban New Zealand. We identified and visited ('mapped') 1230 food outlets (473 urban, 757 rural) across the Waikato/Lakes areas (162 census areas within twelve regions) in New Zealand, where the Te Wai O Rona: Diabetes Prevention Strategy was underway. At each site, we assessed the availability of 'healthy' foods (e.g. wholemeal bread) and compared their cost with those of comparable 'regular' foods (e.g. white bread). Healthy foods were generally more available in urban than rural areas. In both urban and rural areas, 'healthy' foods were more expensive than 'regular' foods after adjusting for the population and income level of each area. For instance, there was an increasing price difference across bread, meat, poultry, with the highest difference for sugar substitutes. The weekly family cost of a 'healthy' food basket (without sugar) was 29.1% more expensive than the 'regular' basket ($NZ 176.72 v. $NZ 136.84). The difference between the 'healthy' and 'regular' basket was greater in urban ($NZ 49.18) than rural areas ($NZ 36.27) in adjusted analysis. 'Healthy' foods were more expensive than 'regular' choices in both urban and rural areas. Although urban areas had higher availability of 'healthy' foods, the cost of changing to a healthy diet in urban areas was also greater. Improvement in the food environment is needed to support people in adopting healthy food choices.

  19. Work-related stress and work ability among Croatian university hospital midwives.

    PubMed

    Knezevic, Bojana; Milosevic, Milan; Golubic, Rajna; Belosevic, Ljiljana; Russo, Andrea; Mustajbegovic, Jadranka

    2011-04-01

    to explore the sources and levels of stress at work and work ability among Croatian midwives. midwives are subjected to multiple stressors. Among health-care professionals, psychological distress for a prolonged period of time has negative effects on the worker's health, work ability and quality of patient care. 'Work ability' is a term describing a worker's resources related to physical, mental and social demands at work. As a measure of work ability in midwifery, the Work Ability Index (WAI) is considered to be a very predictive instrument; midwives with a poor WAI score usually leave their current job within five years. university hospitals in Zagreb, Croatia. cross-sectional design survey. 300 health-care workers (105 qualified midwives and 195 paediatric nurses) were invited to complete the questionnaire. The total response rate was 53% (158/300). The sample included 14.7% of all hospital-based midwives in Zagreb hospitals. the Occupational Stress Assessment Questionnaire (OSAQ) for health-care workers and the WAI questionnaire. over three-quarters of the midwives (46/60, 76.7%) believed that their job was stressful, and considered that insufficient work resources caused the most stress. More than half of the midwives associated an insufficient number of coworkers, unexpected situations, inadequate income, night work, incurable patients and poor organisation at work with a high level of stress. The perceived specific stressors differed between midwives and paediatric nurses in the same hospital. Insufficient work resources and poor organisation at work were more common stressors among midwives than paediatric nurses (p<0.05). Midwives and nurses differed significantly with respect to age (p=0.002). Midwives were younger and had spent fewer years working in their current workplace compared with paediatric nurses (p<0.001). Also, midwives had a lower level of education than paediatric nurses (p=0.044). The mean WAI score for midwives was 40.0 [95% confidence

  20. Zinc Absorption from Milk Is Affected by Dilution but Not by Thermal Processing, and Milk Enhances Absorption of Zinc from High-Phytate Rice in Young Dutch Women.

    PubMed

    Talsma, Elise F; Moretti, Diego; Ly, Sou Chheng; Dekkers, Renske; van den Heuvel, Ellen Ghm; Fitri, Aditia; Boelsma, Esther; Stomph, Tjeerd Jan; Zeder, Christophe; Melse-Boonstra, Alida

    2017-06-01

    Background: Milk has been suggested to increase zinc absorption. The effect of processing and the ability of milk to enhance zinc absorption from other foods has not been measured directly in humans. Objective: We aimed to assess zinc absorption from 1 ) milk undergoing various processing and preparatory steps and 2 ) from intrinsically labeled high-phytate rice consumed with milk or water. Methods: Two randomized crossover studies were conducted in healthy young women [age:18-25 y; body mass index (in kg/m 2 ): 20-25]: 1 ) a milk study ( n = 19) comparing the consumption of 800 mL full-fat ultra-high temperature (UHT) milk [heat-treated milk (HTM)], full-fat UHT milk diluted 1:1 with water [heat-treated milk and water (MW)], water, or unprocessed (raw) milk (UM), each extrinsically labeled with 67 Zn, and 2 ) a rice study ( n = 18) comparing the consumption of 90 g intrinsically 67 Zn-labeled rice with 600 mL of water [rice and water (RW)] or full-fat UHT milk [rice and milk (RM)]. The fractional absorption of zinc (FAZ) was measured with the double-isotope tracer ratio method. In vitro, we assessed zinc extraction from rice blended into water, UM, or HTM with or without phytate. Results: FAZ from HTM was 25.5% (95% CI: 21.6%, 29.4%) and was not different from UM (27.8%; 95% CI: 24.2%, 31.4%). FAZ from water was higher (72.3%; 95% CI: 68.7%, 75.9%), whereas FAZ from MW was lower (19.7%; 95% CI: 17.5%, 21.9%) than HTM and UM (both P < 0.01). FAZ from RM (20.7%; 95% CI: 18.8%, 22.7%) was significantly higher than from RW (12.8%; 95% CI: 10.8%, 14.6%; P < 0.01). In vitro, HTM and UM showed several orders of magnitude higher extraction of zinc from rice with HTM than from rice with water at various phytate concentrations. Conclusions: Milk enhanced human FAZ from high-phytate rice by 62% compared with water. Diluting milk with water decreases its absorption-enhancing proprieties, whereas UHT processing does not. This trial was registered at the Dutch trial registry as