261 research outputs found

    Buying the Same Horse Twice: The U.S. Embassy in Moscow, 1944-1945

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    This thesis analyzes the US Embassy in Moscow at the end of World War II by examining the experiences and perspectives of the Embassy’s three major figures: Ambassador W. Averell Harriman, Charge d’Affaires George F. Kennan, and Major General John R. Deane. These men did not begin as staunch Slavophobes or anti-Communists. But from the failed Warsaw Uprising in August 1944 to the war’s end in May 1945, these three men began to believe that the USSR was trying to project its influence over the rest of Eastern Europe. The US Embassy encountered great difficulty in its dealings with the Soviet Government as disagreements arose over the governance of Poland and the issue of prisoner repatriation. After the Yalta Conference, Deane, Harriman, and Kennan believed that the USSR was violating the Declaration on Liberated Europe as it attempted to dominate the political and economic affairs of Eastern European countries under its occupation. In response, these officials called for a tougher foreign policy against the USSR in order to stop it from establishing a permanent sphere of influence. By analyzing this historical narrative, this thesis helps explain why US-USSR relations began to deteriorate by the war’s end, which in turn led to the Cold War

    Detection and clearing of trapped ions in the high current Cornell photoinjector

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    We have recently performed experiments to test the effectiveness of three ion-clearing strategies in the Cornell high intensity photoinjector: DC clearing electrodes, bunch gaps, and beam shaking. The photoinjector reaches a new regime of linac beam parameters where high CW beam currents lead to ion trapping. Therefore ion mitigation strategies must be evaluated for this machine and other similar future high current linacs. We have developed several techniques to directly measure the residual trapped ions. Our two primary indicators of successful clearing are the amount of ion current removed by a DC clearing electrode, and the absence of bremsstrahlung radiation generated by beam-ion interactions. Measurements were taken for an electron beam with an energy of 5 MeV and CW beam currents in the range of 1-20 mA. Several theoretical models have been developed to explain our data. Using them, we are able to estimate the clearing electrode voltage required for maximum ion clearing, the creation and clearing rates of the ions while employing bunch gaps, and the sinusoidal shaking frequency necessary for clearing via beam shaking. In all cases, we achieve a maximum ion clearing of at least 70 percent or higher, and in some cases our data is consistent with full ion clearing

    Greenmission: An off-grid energy system

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    In alignment with Santa Clara University\u27s sustainability ideology, the outdoor science school WaldenWest desired to further its students\u27 education through a greenhouse with working electricity. Following greenhouse purchase and assembly, underground wiring for AC, DC and Ethernet lines were sized and installed. A substation was then designed and built in a designated shed, integrating wind turbines and photovoltaics rom past capstone projects. New charge controllers, batteries and circuit breakers were urchased and configured for the system. Worst-case electrical load and solar shading analyses also revealed that these older energy sources were collectively inadequate, so a secondary solar array was designed and flush-mounted to the shed roof; the system falls lightly short of desired year-round performance, but is otherwise a drastic improvement. Electrical measurements show that power is received at the greenhouse with a less than 3% voltage drop, meeting national Electric Code standards. To maintain the greenhouse environment, substation loads are specifically selected to allow for temperature control. These are driven by the Supervisory Control And Data Acquisition (SCADA) system, which never leaves the greenhouse; an enclosed Raspberry Pi automates load operation through SainSmart relays and simple comparative logic. To account for both varying seasonal weather conditions and client accessibility, a Graphical User Interface (GUI) is programmed to allow adjustment of all relevant control parameters via Wi-Fi in real-time. A battery monitor from a past capstone project is also reconfigured to run on Linux to estimate remaining stored energy. Project analyses include ethical, aesthetics, commercial benefit and basic photovoltaic rate-of-return analyses. Hypothetical scenarios are frequently presented to investigate the potential consequences of client and residentially-replicated usage of the entire system. It is also estimated that the combined photovoltaics will result in a lifetime net zero energy in 4.3 years of continuous expected use. Future project work involves tasks that could not be accomplished within the project time frame and budget. Among these include a larger solar array; the 24VDC integration of the horizontal wind turbine; rigorous seasonally-based testing of temperature controlling mechanisms for better parameter adjustments; and finally, the propagation of electrical power beyond the immediate premises and into the entire Walden West garden. Based on client needs, inspiration for future project work will likely draw from the tremendous success of the Milwaukee, Wisconsin non-profit organization, Growing Power

    Interventions encouraging the use of systematic reviews by health policymakers and managers: A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Systematic reviews have the potential to inform decisions made by health policymakers and managers, yet little is known about the impact of interventions to increase the use of systematic reviews by these groups in decision making.</p> <p>Methods</p> <p>We systematically reviewed the evidence on the impact of interventions for seeking, appraising, and applying evidence from systematic reviews in decision making by health policymakers or managers. Medline, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, Health Technology Assessment Database, and LISA were searched from the earliest date available until April 2010. Two independent reviewers selected studies for inclusion if the intervention intended to increase seeking, appraising, or applying evidence from systematic reviews by a health policymaker or manager. Minimum inclusion criteria were a description of the study population and availability of extractable data.</p> <p>Results</p> <p>11,297 titles and abstracts were reviewed, leading to retrieval of 37 full-text articles for assessment; four of these articles met all inclusion criteria. Three articles described one study where five systematic reviews were mailed to public health officials and followed up with surveys at three months and two years. The articles reported from 23% to 63% of respondents declaring they had used systematic reviews in policymaking decisions. One randomised trial indicated that tailored messages combined with access to a registry of systematic reviews had a significant effect on policies made in the area of healthy body weight promotion in health departments.</p> <p>Conclusions</p> <p>The limited empirical data renders the strength of evidence weak for the effectiveness and the types of interventions that encourage health policymakers and managers to use systematic reviews in decision making.</p

    Demonstration of Low Emittance in the Cornell Energy Recovery Linac Injector Prototype

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    We present a detailed study of the six-dimensional phase space of the electron beam produced by the Cornell Energy Recovery Linac Photoinjector, a high-brightness, high repetition rate (1.3 GHz) DC photoemission source designed to drive a hard x-ray energy recovery linac (ERL). A complete simulation model of the injector has been constructed, verified by measurement, and optimized. Both the horizontal and vertical 2D transverse phase spaces, as well as the time-resolved (sliced) horizontal phase space, were simulated and directly measured at the end of the injector for 19 pC and 77 pC bunches at roughly 8 MeV. These bunch charges were chosen because they correspond to 25 mA and 100 mA average current if operating at the full 1.3 GHz repetition rate. The resulting 90% normalized transverse emittances for 19 (77) pC/bunch were 0.23 +/- 0.02 (0.51 +/- 0.04) microns in the horizontal plane, and 0.14 +/- 0.01 (0.29 +/- 0.02) microns in the vertical plane, respectively. These emittances were measured with a corresponding bunch length of 2.1 +/- 0.1 (3.0 +/- 0.2) ps, respectively. In each case the rms momentum spread was determined to be on the order of 1e-3. Excellent overall agreement between measurement and simulation has been demonstrated. Using the emittances and bunch length measured at 19 pC/bunch, we estimate the electron beam quality in a 1.3 GHz, 5 GeV hard x-ray ERL to be at least a factor of 20 times better than that of existing storage rings when the rms energy spread of each device is considered. These results represent a milestone for the field of high-brightness, high-current photoinjectors.Comment: Physical Review Special Topics - Accelerators and Beams 16, 073401 (2013

    Photocathode Behavior During High Current Running in the Cornell ERL Photoinjector

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    The Cornell University Energy Recovery Linac (ERL) photoinjector has recently demonstrated operation at 20 mA for approximately 8 hours, utilizing a multialkali photocathode deposited on a Si substrate. We describe the recipe for photocathode deposition, and will detail the parameters of the run. Post-run analysis of the photocathode indicates the presence of significant damage to the substrate, perhaps due to ion back-bombardment from the residual beamline gas. While the exact cause of the substrate damage remains unknown, we describe multiple surface characterization techniques (X-ray fluorescence spectroscopy, X-ray diffraction, atomic force and scanning electron microscopy) used to study the interesting morphological and crystallographic features of the photocathode surface after its use for high current beam production. Finally, we present a simple model of crystal damage due to ion back-bombardment, which agrees qualitatively with the distribution of damage on the substrate surface.Comment: 20 pages, 15 figure

    Immunoelectron microscopic localization of HLA-DR antigen in control small intestine and colon and in inflammatory bowel disease

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    We have elucidated the distribution of I2 (HLA-DR) antigen in control and inflammatory bowel disease specimens, using immunoelectron microscopic methods. Control small intestinal epithelium and inflammatory bowel disease epithelium expressed I2 antigen, while control colonic epithelium did not. I2 expression by enterocytes was more frequent on the lateral and basal surface than on the microvillus surface. Two of three M cells in control ileum expressed I2 antigen. I2-positive intraepithelial lymphocytes were rarely detected in both control and disease specimens. I2-positive lamina propria lymphocytes were significantly increased in inflammatory bowel disease, while I2-positive lamina propria lymphocytes were virtually absent in control specimens. I2-positive mononuclear cells in the intestinal lamina propria were largely macrophages and monocytes in both control and inflammatory bowel disease specimens. I2-positive mononuclear cells resembling dendritic cells were not detected in control or disease specimens. Furthermore, there were no significant morphological differences in I2-positive or-negative macrophages and monocytes in control and disease specimens. The expression of I2 antigen on Schwann cells was detected more frequently in disease specimens than in control specimens. Capillary endothelia of both control and disease specimens expressed I2 antigen. We demonstrate that I2 expression is present on surface membranes of both immune and nonimmune cells of the intestine and colon and show that this expression is more prominent in inflammatory bowel disease than in control intestine and colon. Further studies are required to determine whether this finding is meaningful in terms of antigen presentation and whether this apparent “immune activation” is involved in the pathogenesis of inflammatory bowel disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44398/1/10620_2005_Article_BF01299810.pd

    Ischemic stroke risk, smoking, and the genetics of inflammation in a biracial population: the stroke prevention in young women study

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    <p>Abstract</p> <p>Background</p> <p>Although cigarette smoking is a well-established risk factor for vascular disease, the genetic mechanisms that link cigarette smoking to an increased incidence of stroke are not well understood. Genetic variations within the genes of the inflammatory pathways are thought to partially mediate this risk. Here we evaluate the association of several inflammatory gene single nucleotide polymorphisms (SNPs) with ischemic stroke risk among young women, further stratified by current cigarette smoking status.</p> <p>Methods</p> <p>A population-based case-control study of stroke among women aged 15–49 identified 224 cases of first ischemic stroke (47.3% African-American) and 211 age-comparable control subjects (43.1% African-American). Several inflammatory candidate gene SNPs chosen through literature review were genotyped in the study population and assessed for association with stroke and interaction with smoking status.</p> <p>Results</p> <p>Of the 8 SNPs (across 6 genes) analyzed, only <it>IL6 </it>SNP rs2069832 (allele C, African-American frequency = 92%, Caucasian frequency = 55%) was found to be significantly associated with stroke using an additive model, and this was only among African-Americans (age-adjusted: OR = 2.2, 95% CI = 1.0–5.0, p = 0.049; risk factor adjusted: OR = 2.5, 95% CI = 1.0–6.5, p = 0.05). When stratified by smoking status, two SNPs demonstrated statistically significant gene-environment interactions. First, the T allele (frequency = 5%) of <it>IL6 </it>SNP rs2069830 was found to be protective among non-smokers (OR = 0.30, 95% CI = 0.11–.082, p = 0.02), but not among smokers (OR = 1.63, 95% CI = 0.48–5.58, p = 0.43); genotype by smoking interaction (p = 0.036). Second, the C allele (frequency = 39%) of <it>CD14 </it>SNP rs2569190 was found to increase risk among smokers (OR = 2.05, 95% CI = 1.09–3.86, p = 0.03), but not among non-smokers (OR = 0.93, 95% CI = 0.62–1.39, p = 0.72); genotype by smoking interaction (p = 0.039).</p> <p>Conclusion</p> <p>This study demonstrates that inflammatory gene SNPs are associated with early-onset ischemic stroke among African-American women (<it>IL6</it>) and that cigarette smoking may modulate stroke risk through a gene-environment interaction (<it>IL6 and CD14</it>). Our finding replicates a prior study showing an interaction with smoking and the C allele of <it>CD14 </it>SNP rs2569190.</p
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