301 research outputs found

    Analysis and Experimental Tests of a High-Performance Evacuated Tubular Collector

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    A high-performance collector based on the use of all-glass, evacuated tubular collector elements is described and analyzed, and supporting experimental data presented. The collector operated with excellent efficiency at temperatures high enough to drive existing air conditioning units, and showed good performance under diffuse light and low insolation conditions. Collector efficiency was insensitive to operating temperature, ambient temperature, and wind speed. In addition, air, as well as liquid, can be used as the heat transfer fluid, with no significant performance penalty. While the equations governing the useful energy produced can be cast in a form similar to that for flat plate collectors, several important parameters were unique in a number of respects. The loss coefficient was unusually low, while the flow factor and effective insolation were unusually high

    Early and late complications of bariatric operation.

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    Weight loss surgery is one of the fastest growing segments of the surgical discipline. As with all medical procedures, postoperative complications will occur. Acute care surgeons need to be familiar with the common problems and their management. Although general surgical principles generally apply, diagnoses specific to the various bariatric operations must be considered. There are anatomic considerations which alter management priorities and options for these patients in many instances. These problems present both early or late in the postoperative course. Bariatric operations, in many instances, result in permanent alteration of a patient\u27s anatomy, which can lead to complications at any time during the course of a patient\u27s life. Acute care surgeons diagnosing surgical emergencies in postbariatric operation patients must be familiar with the type of surgery performed, as well as the common postbariatric surgical emergencies. In addition, surgeons must not overlook the common causes of an acute surgical abdomen-acute appendicitis, acute diverticulitis, acute pancreatitis, and gallstone disease-for these are still among the most common etiologies of abdominal pathology in these patients

    Selective-Area Growth of Heavily \u3cem\u3en\u3c/em\u3e–Doped GaAs Nanostubs on Si(001) by Molecular Beam Epitaxy

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    Using an aspect ratio trapping technique, we demonstrate molecular beam epitaxy of GaAs nanostubs on Si(001) substrates. Nanoholes in a SiO2 mask act as a template for GaAs-on-Si selective-area growth(SAG) of nanostubs 120 nm tall and ≤100 nm in diameter. We investigate the influence of growthparameters including substrate temperature and growth rate on SAG. Optimizing these parameters results in complete selectivity with GaAsgrowth only on the exposed Si(001). Due to the confined-geometry, strain and defects in the GaAs nanostubs are restricted in lateral dimensions, and surface energy is further minimized. We assess the electrical properties of the selectively grownGaAs nanostubs by fabricating heterogeneous p+–Si/n+–GaAs p–n diodes

    EFFECTS OF KAATSU TRAINING ON UPPER EXTREMITY SIZE AND STRENGTH

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    poster abstractConventional resistance training involves lifting heavy loads (~70% max-imal strength), which can be poorly tolerated or contraindicated in many clinical populations. KAATSU training is a novel training mode from Japan that combines muscle blood flow restriction with low load lifting (~20% max-imal strength). The purpose of this study was to investigate the effects of a KAATSU training program on upper extremity size and strength. Forty healthy subjects ages 18 to 30 were divided into exercise (EX) or control (CON) groups. Subjects reported to the laboratory three times per week for eight weeks. The EX group performed 3 sets of 15 repetitions of unilateral bicep curls and triceps extensions lifting loads equivalent to 20% of their predetermined maximal strength while wearing a pneumatic cuff to restrict blood flow on one arm (CUFF) and nothing on the other (NCUFF). The CON group did not perform any exercises but wore the cuff on one arm for a time comparable to the EX group. CUFF and NCUFF arms were randomly as-signed. Strength, girth, skin folds and tomography scans were taken pre-, during, and post-eight weeks. In the EX group, bicep curl (17.4% +4.1% and 18.7% +4.9%) and triceps extension (15.8% +3.4% and 10.7% +2.7%) strength increased significantly over the 8-week period for both the CUFF and NCUFF arms, respectively. No significant differences in strength occurred between the CUFF and NCUFF arms within the group. No strength changes were noted in the CON group for the CUFF and NCUFF arms. Arm girth and muscle cross-sectional area (mCSA) increased significantly in the EX subjects compared to the CON subjects, however no significant differ-ences were found when within group comparisons were made between the CUFF and NCUFF arms. This study indicates that KAATSU training can in-crease muscle strength and mCSA

    KAATSU TRAINING: PERCEPTIONS AND COMPLIANCE TO AN UPPER ARM EXERCISE PROGRAM

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    poster abstractKAATSU training is a novel Japanese training mode involving low load (~20% maximal strength) weightlifting combined with blood flow restriction to the muscles. Little is known about the sensations experienced during KAATSU training and whether clients will tolerate it. The purpose of this study was to assess perceived sensations, exertion rates, and compliance to an upper arm KAATSU training program. Forty healthy subjects ages 18 to 30 were divided into exercise (EX) or control (CON) groups. Subjects report-ed to the laboratory three times per week for eight weeks. The EX group performed 3 sets of 15 repetitions of unilateral bicep curls and triceps exten-sions lifting loads equivalent to 20% of their predetermined maximal strength while wearing a pneumatic cuff on one arm (CUFF) and nothing on the other (NCUFF). The CON group did not perform any exercises but wore the cuff on one arm for a time comparable to the EX group. CUFF and NCUFF arms were randomly assigned. Sensations (burning, aching, pressure, pins & needles) and perceived exertion were assessed using visual analog scales that included emotions and verbal cues. Compliance (percentage of subjects completing the pre- and post-testing) and adherence (percentage of ses-sions completed) were tracked to provide an indication of training tolerance. Compliance was 85.4% and 97% for the EX and CON groups, respectively. EX subjects completed 85.4% of their workouts while controls attended 90.4% of their sessions. The prominent sensation reported in the CUFF arm was pressure (moderate; 3.2 +0.6) followed by aching (weak; 1.7 +0.4). Ratings of perceived exertion were higher for the CUFF (3.2 +1.0, 5.1 +1.8, and 7.0 +2.5) versus NCUFF (1.5 +0.3, 2.4 +0.3, and 3.3 +0.4) arm for sets 1, 2, and 3, respectively. KAATSU training is well tolerated by those performing it and a viable alternative to conventional resistance exercise

    The NASA Exoplanet Archive: Data and Tools for Exoplanet Research

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    We describe the contents and functionality of the NASA Exoplanet Archive, a database and tool set funded by NASA to support astronomers in the exoplanet community. The current content of the database includes interactive tables containing properties of all published exoplanets, Kepler planet candidates, threshold-crossing events, data validation reports and target stellar parameters, light curves from the Kepler and CoRoT missions and from several ground-based surveys, and spectra and radial velocity measurements from the literature. Tools provided to work with these data include a transit ephemeris predictor, both for single planets and for observing locations, light curve viewing and normalization utilities, and a periodogram and phased light curve service. The archive can be accessed at http://exoplanetarchive.ipac.caltech.edu.Comment: Accepted for publication in the Publications of the Astronomical Society of the Pacific, 4 figure

    Cirurgia para o controle de danos: Sua evolução durante os últimos 20 anos

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    In less than twenty years, what began as a concept for the treatment of exsanguinating truncal trauma patients has become the primary treatment model for numerous emergent, life threatening surgical conditions incapable of tolerating traditional methods. Its core concepts are relative straightforward and simple in nature: first, proper identification of the patient who is in need of following this paradigm; second, truncation of the initial surgical procedure to the minimal necessary operation; third, aggressive, focused resuscitation in the intensive care unit; fourth, definitive care only once the patient is optimized to tolerate the procedure. These simple underlying principles can be molded to a variety of emergencies, from its original application in combined major vascular and visceral trauma to the septic abdomen and orthopedics. A host of new resuscitation strategies and technologies have been developed over the past two decades, from permissive hypotension and damage control resuscitation to advanced ventilators and hemostatic agents, which have allowed for a more focused resuscitation, allowing some of the morbidity of this model to be reduced. The combination of the simple, malleable paradigm along with better understanding of resuscitation has proven to be a potent blend. As such, what was once an almost lethal injury (combined vascular and visceral injury) has become a survivable one

    An Analysis of the Nonprofit and Volunteer Capacity-Building Industries in Central Texas

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    Based on a Collaboration of The LBJ School of Public Affairs at the University of Texas at Austin & The Bush School of Government and Public Service at Texas A&M UniversityRecent research has identified explosive growth in the nonprofit sector and an increased interest in evaluating and improving nonprofit performance through organizational capacity building. The growing emphasis on capacity-building services for nonprofits nationwide has resulted in the need for better information about support services for the sector. Considering the burgeoning role of capacity building in nonprofit operations, it is important to understand more about the industry that provides support and resources to nonprofits, including in the growing communities located in Central Texas. This report represents the first comprehensive study of nonprofit and volunteer capacity-building activities in Central Texas. The result of a unique collaboration between graduate students at the Bush School of Government and Public Service at Texas A&M University and the Lyndon B. Johnson School of Public Affairs at The University of Texas at Austin, this study was conducted under the supervision of Dr. Angela Bies at the Bush School and Dr. Sarah Jane Rehnborg at the LBJ School. Twenty-three graduate students in both programs conducted the research and analysis for this report from September 2005 through April 2006. The Bush School and the RGK Center for Philanthropy and Community Service at the LBJ School provided funding for the study. The project also partnered on a pro bono basis with two client organizations, the United Way Capital Area and the Texas Nonprofit Management Assistance Network. The primary research objective was to replicate two recent studies. The first was Millesen and Bies 2004 report for the Forbes Funds, An Analysis of the Pittsburgh Region s Capacity- Building Industry. The second was an examination of volunteer management capacity modeled on a nationwide volunteer management study (Hager, 2004) conducted by the Urban Institute in collaboration with the Corporation for National and Community Service. Because our research took place in the aftermath of Hurricanes Katrina and Rita in 2005, we also explored nonprofit capacity issues related to emergency interventions, particularly how crises affect organizations needs for and uses of capacity building.United Way Capital Area; Texas Nonprofit Management Assistance Networ

    Clinical review: Allocating ventilators during large-scale disasters – problems, planning, and process

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    Catastrophic disasters, particularly a pandemic of influenza, may force difficult allocation decisions when demand for mechanical ventilation greatly exceeds available resources. These situations demand integrated incident management responses on the part of the health care facility and community, including resource management, provider liability protection, community education and information, and health care facility decision-making processes designed to allocate resources as justly as possible. If inadequate resources are available despite optimal incident management, a process that is evidence-based and as objective as possible should be used to allocate ventilators. The process and decision tools should be codified pre-event by the local and regional healthcare entities, public health agencies, and the community. A proposed decision tool uses predictive scoring systems, disease-specific prognostic factors, response to current mechanical ventilation, duration of current and expected therapies, and underlying disease states to guide decisions about which patients will receive mechanical ventilation. Although research in the specifics of the decision tools remains nascent, critical care physicians are urged to work with their health care facilities, public health agencies, and communities to ensure that a just and clinically sound systematic approach to these situations is in place prior to their occurrence
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