Versatile, low-cost, computer-controlled, sample positioning system for vacuum applications

A versatile, low-cost, easy to implement, microprocessor-based motorized positioning system (MPS) suitable for accurate sample manipulation in a Second Ion Mass Spectrometry (SIMS) system, and for other ultra-high vacuum (UHV) applications was designed and built at NASA LeRC. The system can be operated manually or under computer control. In the latter case, local, as well as remote operation is possible via the IEEE-488 bus. The position of the sample can be controlled in three linear orthogonal and one angular coordinates

Expanding the social-cognitive framework: understanding the role of implicit person theories in a complex task feedback environment

Department Head: Ernest L. Chavez.2010 Spring.Includes bibliographical references (pages 139-155).The current study employed a longitudinal design to examine the effects of implicit person theories (IPTs; Dweck & Leggett, 1988) on task performance over two measurement occasions and a week of temporal separation. This design allowed for a direct inquiry into the pivotal role that one's lay beliefs about the malleability of attributes play in a simulated task feedback environment. In addition to examining the direct effects of IPT on task performance, the study investigated the role of the mediated mechanisms of appraisal effectiveness (i.e., feedback reactions), goal setting, effort, and attributions in the IPT-task performance relationship. Further, the study investigated the conditional indirect effect of feedback sign (i.e., positive vs. negative) on the meditational mechanisms, otherwise known as moderated mediation. 242 psychology students participated in the study for course credit. Limited evidence for the proposed meditational models was provided. Overall, IPTs significantly positively predicted task performance following the receipt of feedback after a one-week lag in measurement. Furthermore, the sign of the feedback was a significant, positive predictor of the full class of feedback reactions. Notably, the full class of reactions to feedback were all positively related to task 2 performance, providing empirical evidence of the predictive validity of appraisal feedback reactions for subsequent performance. Implications of the results, future research directions, and limitations are discussed

Attending Weak Signals: The Prevention of Work-related Illnesses

This article examines the characteristics of communication among managers, human resource (HR) experts, and occupational health care specialists, as they deal with such informal information as weak signals in the prevention of work-related illnesses, using a theoretical framework in which the prevention of work-related illness is analogous to theory on crisis management. This is a qualitative study in which individual and focus-group interviews were conducted in a Swedish context with occupational health care specialists, managers, and HR experts. The results suggest that organizational solutions have failed and continue to fail at controlling workers’ health problems, although the main difficulty is not in identifying the ‘right’ individually oriented weak signals. Rather, it is upper management’s reliance on formal information (e.g., statistics and surveys) – because of the difficulty in supplementing it with informal information (e.g., rumors and gossip) – that makes it difficult to improve traditional health and safety wor

Potential for Acid Snowmelt in the Wasatch Mountains

Snowmelt collected from snow cores taken from the 1982 spring snowpack in the Wasatch Mountains of northern Utah lacked mineral acidity and retained enough buffering capacity in the form of calcium and magnesium bicarbonates to titrate additional inputs of strong acid equivalent to the amount apparently already neutralized. While acid anion concentrations were higher than those found in pristine areas, they were much lower than those reported for winter precipitation in other western areas experiencing acidification of precipitation. Snowmelt pH ranged from 5.62 to 6.88 (mean = 6.17), and sulfate was relatively more important than nitrate, showing an average equivalent ratio of 3.1:1. Patterns of pH indicated decreasing pH with distance from sources of soil-derived buffering capacity in the semiarid valleys to the east. Although acid anion concentration patterns failed to point to pollution sources along the Wasatch Front, chloride concentration patterns indicated that the Salt Lake Valley airshed influenced snow chemistry in the mountains. Snowmelt studies carried on in the laboratory and at a field site in Logan Canyon indicated that, for the alkaline snow typical of 1982, the first melt fractions had a higher pH (less acidity) than did the bulk snow. The opposite situation is typically found for acid snow. Although no acidity was present, snow pH increased by 13 percent as a result of contact with organic litter on the soil surface of a 22 m, 32 percent slope. The pH increased even more rapidly in a nearby intermittent stream 9to 7.78 at the edge of the snowpack). Difficulties in interpreting the data from the snow cores in this study include the effects of an unusually wet winter, uncharacteristically low levels of industrial activity due to economic factors, uncertainty about the relative amounts of acidity and buffering capacity reaching the sensitive Uintah Mountain watersheds to the east, and failure to distinguish between soil and acid derived sulfates. Analysis of these difficulties suggests taht offsetting factors would tend to cancel effects of precipitation amount during wet-to-normal winters. the remaining factors require additional research

The Detection of Neuropsychological Malingering

The present study compared the responses of a group of simulating malingerers who were offered a monetary incentive to feign symptoms of a head injury, with the responses of head injured groups both with and without litigation, a forensic parole group, and an honest-responding control group. The following six neuropsychological measures were utilized: Rey 15-Item Memory Test, Controlled Oral Word Association Test, Finger Oscillation Test, WAIS-R Neuropsychological Instrument (Vocabulary, Information, and Similarities subtests), Booklet Category Test, and Wisconsin Card Sorting Test. The statistical concepts of floor effect, performance curve, and magnitude of error were examined. Additionally, the statistical differences in the responses of the five groups were analyzed to determine cutting scores for use in distinguishing malingerers from nonmalingerers

Reduction of Vertical Transmission of HIV in the Dominican Republic: Benefits of Early Presentation for Prenatal Care

Background:The impact of HIV infection on maternal and infant mortality in the Dominican Republic is unknown. The prevalence of HIV infection among pregnant women in the Dominican Republic is 1-2%, and over two-thirds of women receive prenatal care. (2,3) It is estimated that 15% of all deliveries in the Dominican Republic occur at the Hospital Maternidad Nuestra Señora de la Altagracia in Santo Domingo, making this the highest-volume maternity hospital in the country.(4) Objectives:We conducted a study to compare the impact of HIV infection on pregnant women receiving prenatal care including highly active antiretroviral therapy (HAART) versus women who were not identified as HIV positive until the time of delivery. All research took place at the Hospital Maternidad Nuestra Señora de la Altagracia, Santo Domingo, DR. Methods:We performed a retrospective chart review at the Office of Reduction of Vertical Transmission of HIV at the Hospital Maternidad Nuestra Señora de la Altagracia. All deliveries between May and September, 2009, were included. Data were compared to a record book listing monthly deliveries of HIV infected women. This database was the primary source of data on HIV positive women who delivered at the Altagracia, but who did not receive prenatal care at the PMTCT office at the Altagracia. Data points included: patient age at time of presentation to the PMTCT clinic or at the time of initial presentation for delivery; gestational age at time of presentation; gestational age at start of HAART; mode of delivery; whether a woman was less than 20 years old at time of presentation; whether she gave birth to a living child; and the type of treatment the child received after delivery. All data were collected in a de-identified manner by Ingrid Liff, a senior medical student at the University of Massachusetts Medical School. This study was approved by the IRB at the University of Massachusetts.(5) Results:Between May and September, 2009, we identified 91 HIV positive women who delivered at the Altagracia. Forty-nine women (54%) received prenatal care through the Office for Reduction of Vertical Transmission of HIV. All of these 49 women received HAART prior to delivery. Of these 49 women, 80% underwent Cesarean delivery, and 12% were adolescents (old). There was no infant mortality in this group. Forty-two women (46%) were identified as HIV infected at the time of labor, and only 7% of these women received HAART prior to delivery. Sixty-two percent of these women received no treatment for HIV infection prior to delivery. Seven percent received single dose nevirapine and 14% received Colita. (6) Of these 42 women, 48% underwent Cesarean delivery, 21% were adolescents (old), and there were 2 infant deaths. According to data collected at the time of delivery, all living newborns delivered to the HIV positive mothers in our study received treatment with a 6-week course of zidovudine (AZT) per national protocol. All of the newborns also received formula at the time of delivery and were not breastfed. Conclusions:This observational study emphasizes the need for a more aggressive approach to identify HIV infected pregnant women prior to labor. In this cohort, all HIV positive pregnant women who received prenatal care at the PMTCT clinic received HAART prior to delivery, as opposed to those who were identified during labor. Until recently, newborns born at the Altagracia were lost to follow-up. At this time there is no data on whether the infants in this study population are HIV positive. Further research is warranted to uncover the rate of vertical transmission at the Hospital Maternidad Nuestra Señora de la Altagracia in Santo Domingo. (1) Iniciativa Latinoamericana y del Caribe de Integración de la Atención Prenatal con la Detección y el Manejo Clínico del VIH y de la Sífilis (ILAP) (2) WHO, UNICEF, UNAIDS. Dominican Republic 2008 Update: Epidemiological Fact Sheet on HIV and AIDS. Published by the UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance, December, 2008. (3) Perez-Then E, Pena R, Tavarez-Rojas M, Pena C, Quinonez S, Buttler M, et al. Preventing Mother-to-Child HIV Transmission in a Developing Country: The Dominican Republic Experience. J Acquir Immune Defic Syndr 2003,34:506-511.; WHO, UNICEF, UNAIDS. Dominican Republic 2008 Update: Epidemiological Fact Sheet on HIV and AIDS. Published by the UNAIDS/WHO Working Group on Global HIV/AIDS and STI Surveillance, December, 2008. (4) Secretaria de Estado de Salud Pública y Asistencia Social Subsecretaría de Planificación y Desarollo (SESPAS). Informe Estadístico, 2008. (5) IRB Exempt status, #13713 - Prenatal care and treatment for HIV positive women in the Dominican Republic (6) Colita refers to single dose nevirapine prior to delivery, followed by a tail of triple therapy for seven days after delivery. Presented as part of the Senior Scholars Program at the University of Massachusetts Medical School, May 3, 2010

Impacts of Western Coal, Oil Shale, and Tar Sands Development on Aquatic Environmental Quality: A Technical Information Matrix; Volume 1 Introduction and Instructions

Introduction: The Upper Colorado River Basin contains vast deposits of coal, oil shale, and tar sands, which could undergo extensive development should oil prices rise or an international situation restrict oil imports. Naturally, the prospect of development of these alternative fossil fuels resources has led to concern over how extraction and conversion activities will impact environmental quality. A thorough understanding of the nature and magnitude of the resulting envionemental impacts is a necessary prerequisite, if the costs and risks of such activites are to be weighed against the economic benefits. When we set out to evaluated these costs and risks, it soon became obvious that the voluminous literature in this area is difficult to access, often repetitive, and not well integrated into state-of-the-art reviews. This led us to realize the need to categorize and collate the results of such energy-related impact research in a way that would go beyond the compilation of a bibliography, or even keyworking relevant citations. The form of presentation that we eventually selected was the technical information matrix presented in this report. This matrix consists of information on the impacts of coal mining and conversion, oil shale mining and retoring, and tar sands development on four aspects of aquatic environmental quality: surface water and groundwater chemsitry, aquatic ecology, and aquifer modification. The report consists of three parts. This introductory volume contains instruction for use of the technical information matrix, a glossary, and sources of data on energy development and environmental impacts. Two additional looseleaf volumes contain the coal (II), and oil sahel and tar sands matrices (III), respectively, along with the corresponding matrix references and a bibliography of general (summary or overview) references. Each matrix volume also includes a list of symbols and abbreviations used in the matrix. Qualitatively, information on the three categories of fossil fuel development differs principally in amount, type, and geographical specificity. Coal extraction is a well-studied process in the East, where acid mine drainage and metal toxicity are well documented. In the West, surface mining of vast arid and semiarid tracts, as well as generally more alkaline mine drainage, has been less thoroughly studied. Nonetheless, commercial scale operations have been in place for a sufficiently long period, even in the West, to ahve produced a reasonably large data base. Coal conversion processes, although new, have also reached the commercial scale, and information is becoming relatively abundant. Conversely, environmental information is not generally availabel for the Scottish and Russian oil shale industries, or for the primitive industry in the Colorado Basin earlier in the century, and the present day oil shale industry in the west is insufficiently developed to have produced commerical scale case studies. Most information at present comes from pilot or semi-works facilities, and the impacts of a full-scale development over a 20-30 year project life are difficult to predict. Although Alberta, Canada, has a well developed tar sands industry, site specific information on tar sands development in the Colorado Basin is lacking. There are several areas of ommission in the coverage of sources of fossil fuel impact on aquatic environmental quality. Petroleum drilling, whose principal impacts in the Colorado Basin are related to interconnection of saline with good quality aquifers, creation of saline surface springs during exploration and illegal brine disposal practices has been omitted. Also, we have not pursued the effects of acid (e.g., Sox) base (e.g., NH3) or volatile metal (e.g., Hg) emissions to the atmosphere and their subsequent effects on downwind ecosystems when they are returned by precipitation or dry deposition. We have generally omitted the toxicological literature relating to occupational exposure (e.g., skin painting tests, etc.), as well as the impacts of water withdrawals on fish habitat through reduction of natural instream flows. In the latter cases such impacts require site specific consideration of hydrology and channel morphology. The more than 1300 citations in these matrices were gathered from a wide variety of refereed journals, symposium proceedings, government documents, abstracting services, and personal communications with researchers. The papers cited emphasize the period 1970-1981. Greatest emphasis was placed on the more recent literature, but late 1981 papers are probably underrepresented. There is also little doubt that we have failed to include some valuable material found in project reports, oral presentations, masters these, disserations, and similar sources. Certainly some citations were not optimally summarized or categorized, particularly when it was necessary to work from an abstract or summary. Hopefully, such exclusions or poor representations will not result in loss of excessive information or unduly mislead the users. We plan to update the matrix periodically, supplementing new information found with the searching techniques developed thus far and especially with information supplied by users. Updates will be in the form of looseleaf pages to be added to or substituted in Volumes I and II, and will be published as frequently as deemed necessary to cover developments in the subject areas. We would very much appreciate receiving copies (or summaries) of pertinent reports from the users of this matrix, together with corrections or improvements in the content or categorization of material presently in the matrix. There should be sent to: F.J. Post (coal) or Jay Messer (oil shale and tar sands) Utah Water Research Laboratory UMC 82 Utah State University Logan, UT 84322 They will be gratefully included in the next update

El uso de los vídeos educativos en la enseñanza del área de ciencia y ambiente en educación primaria de la I.E. "Herman Busse de la Guerra" - Los Olivos

La presente investigación es el resultado de la observación del “USO DE LOS VÍDEOS EDUCATIVOS EN LA ENSEÑANZA DEL ÁREA DE CIENCIA Y AMBIENTE EN EDUCACIÓN PRIMARIA EN EL COLEGIO HERMAN BUSSE DE LA GUERRA EN LOS OLIVOS”. El tipo de investigación es descriptiva siendo el objetivo principal, determinar el uso de los vídeos educativos empleados en la enseñanza del área de ciencia y ambiente en educación primaria de la institución educativa Hermán Busse de la Guerra en los Olivos. La población estaba constituida por todos los profesores de educación primaria que suman 30 en total ya que la cantidad de la población es pequeña se optó por trabajar con toda esta población de profesores del l°grado hasta el 6°grado de primaria. Para ello se aplicó un instrumento que fue la Escala de Valoración, para evaluar el uso de los vídeos educativos en la enseñanza en el área de ciencia y ambiente; este instrumento permitió describir el uso de los vídeos en la enseñanza por los profesores en los momentos de la clase y también las características de los vídeos en cuanto el aspecto técnico y expresivo. Este instrumento fue validado por juicio de expertos entre ellos un experto temático de la Universidad César Vallejo del departamento de informática educativa; un docente de prácticas profesionales y un metodólogo quienes observaron la forma y el contenido del instrumento. Para demostrar la con fiabilidad de este instrumento se realizó la técnica Test - Retes que es un procedimiento en el cual un determinado instrumento se aplica más de una vez a una misma población por un periodo de tiempo. En cuanto se refiere a los resultados mostraron que los docentes usaban en su mayoría los vídeos educativos para la motivación de los alumnos en sus sesiones de clase y en los demás momentos pedagógicos se da a conocer porcentajes no tan significativos ya que los docentes no usaban estás herramientas en su gran mayoría. Luego con respecto al uso de los vídeos según sus características, el primer aspecto que sobresalió con un porcentaje de 93% fue del aspecto técnico. En el segundo aspecto expresivo se obtuvo el 77% es decir que los docentes al usar los vídeos en su mayoría tenían presente estas características. Ante esto se ha concluido de acuerdo a este estudio que el uso de los vídeos educativos en la enseñanza son usados por los profesores en su mayoría en los momentos de clase del área de ciencia y ambiente teniendo en cuenta los aspectos técnicos y expresivos. Las recomendaciones de esta investigación son las siguientes: Los docentes deben estar informados acerca de estas estrategias tecnológicas en el área de ciencia y ambiente para poder usarlos no solo como medio motivador sino también como desarrollo y evaluación de una sesión de clase. Los docentes deben tener en cuenta al usar los vídeos que respondan a las características de este material y que tengan una finalidad educativa relacionada al área a trabajar

Thermomechanics of nano-filled elastomers

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references.The incorporation of nanoparticles into engineering thermoplastic elastomers affords engineers an opportunity to formulate flexible, tough and multifunctional polymer nanocomposites that potentially rival the most advanced materials in nature. Development of these materials is difficult since thermodynamic and kinetic barriers inhibit the dispersal of inorganic, hydrophilic nanoparticles into inherently hydrophobic polymer matrices. Thermoplastic polyurethanes (TPUs) are particularly attractive nanocomposite matrix materials due to their vast range of potential applications (e.g. in artificial organs, coatings, foams, and active wear), their mechanical versatility, and tunable block-polymeric structure. In this thesis we explore methods for systematically nanoreinforcing such materials by exploiting the microphase structure, differential polarities and multiple thermomechanical phase transitions of the macromolecular blocks that constitute the elastomeric matrix. Using a solvent exchange technique we show that it is possible to preferentially nanoreinforce the hard micro-domains of thermoplastic elastomers with smectic clay nanofillers that have characteristic dimensions similar to the hard segment. The adhesion between the clay and the hard micro-domains coupled with the formation of a percolative network not only stiffens and toughens, but increases the heat distortion temperature (HDT) of the material. The discotic clay platelets induce morphological ordering over a range of length scales that results in significant thermomechanical enhancement and expands high temperature applications. This thesis seeks to further enhance the understanding and utility of thermoplastic polyurethane nanocomposites by answering two questions: (1) what thermo-physical interactions between nano-clay and elastomeric thermoplastic polyurethane are taking place? and (2) how can these thermo-physical interactions be exploited?(cont.) To answer these questions the nano-reinforced-hard micro-domain morphology was monitored during deformation using in-situ wide angle x-ray scattering and combined with the results of extensive quasi-static mechanical testing which enabled the identification two characteristic relaxation times. A one-dimensional constitutive model to account for such morphological changes augmenting the previous model for unfilled polyurethanes developed by Qi and Boyce (2005) is discussed. Finally, the thermo-mechanical influence of nano-clay fillers on the shape memory effects exhibited by polyurethane nanocomposites is examined and multi-responsive shape memory polyurethane fibrous mats are developed via electrospinning. Quantifying and controlling the thermo-physical interactions between a block-copolymer with polar segments (e.g. thermoplastic polyurethane) and inorganic nanoparticles (e.g. nano-clay) is important for future nanocomposite processing strategies: the efficacy of nanoreinforcement hinges upon the close matching of characteristic length scale and the adhesion of the nanoparticles to the targeted polymer phase morphology. Exploiting the different polarity of the blocks in conjunction with solvent exchange approach developed in this thesis and solution processing techniques such as electro-spinning, offers an avenue toward the development of high performance, hierarchically-ordered materials that rival natural materials.by Shawna M. Liff.Ph.D