322 research outputs found
Revisions in Need of Revising: What Went Wrong in the Iraq War
Though critics have made a number of telling points against the Bush administration\u27s conduct of the Iraq war, the most serious problems facing Iraq and its American occupiers—criminal anarchy and lawlessness, a raging insurgency and a society divided into rival and antagonistic groups—were virtually inevitable consequences that flowed from the act of war itself. Military and civilian planners were culpable in failing to plan for certain tasks, but the most serious problems had no good solution. Even so, there are lessons to be learned. These include the danger that the imperatives of force protection may sacrifice the broader political mission of U.S. forces and the need for skepticism over the capacity of outsiders to develop the skill and expertise required to reconstruct decapitated states.https://press.armywarcollege.edu/monographs/1725/thumbnail.jp
Investigation of Plasmon Resonance Tunneling through Subwavelength Hole Arrays in Highly Doped Conductive ZnO Films
Experimental results pertaining to plasmon resonance tunneling through a highly conductive zinc oxide (ZnO) layer with subwavelength hole-arrays is investigated in the mid-infrared regime. Gallium-doped ZnO layers are pulsed-laser deposited on a silicon wafer. The ZnO has metallic optical properties with a bulk plasma frequency of 214 THz, which is equivalent to a free space wavelength of 1.4 μm. Hole arrays with different periods and hole shapes are fabricated via a standard photolithography process. Resonant mode tunneling characteristics are experimentally studied for different incident angles and compared with surface plasmontheoretical calculations and finite-difference time-domain simulations. Transmission peaks, higher than the baseline predicted by diffraction theory, are observed in each of the samples at wavelengths that correspond to the excitation of surface plasmon modes
Biomass round bales infield aggregation logistics scenarios
Biomass bales often need to be aggregated (collected into groups and transported) to a field-edge stack or a temporary storage before utilization. Several logistics scenarios for aggregation involving equipment and aggregation strategies were modeled and evaluated. Cumulative Euclidean distance criteria evaluated the various aggregation scenarios. Application of a single-bale loader that aggregated bales individually was considered as the “control” scenario with which others were compared. A computer simulation program developed determined bale coordinates in ideal and random layouts that evaluated aggregation scenarios. Simulation results exhibited a “diamond pattern” of bales on ideal layout and a “random pattern” emerged when ≥ 10% variation was introduced. Statistical analysis revealed that the effect of field shape, swath width, biomass yield, and randomness on bale layout did not affect aggregation logistics, while area and number of bales handled had significant effects. Number of bales handled in the direct method significantly influenced the efficiency. Self-loading bale picker with minimum distance path (MDP, 80%) and parallel transport of loader and truck with MDP (78%) were ranked the highest, and single-bale central grouping the lowest (29%) among 19 methods studied. The MDP was found significantly more efficient (4%-16%) than the baler path. Simplistic methods, namely a direct triple-bale loader with MDP (64%-66%), or a loader and truck handling six bales running parallel with MDP (75%-82%) were highly efficient. Great savings on cumulative distances that directly influence time, fuel, and cost were realized when the number of bales handled was increased or additional equipment was utilized
Time to Initial Debridement and wound Excision (TIDE) in severe open tibial fractures and related clinical outcome: A multi-centre study
© 2018 Elsevier Ltd Background: Recent national (NICE) guidelines in England recommend that initial debridement and wound excision of open tibial fractures take place within 12 h of the time of injury, a change from the previous target of 24 h. This study aims to assess the effect of timing of the initial debridement and wound excision on major infective complications, the impact of the new guidance, and the feasibility of adhering to the 12 h target within the infrastructure currently existing in four major trauma centres in England. Methods: A retrospective review was performed of Gustilo-Anderson grade 3B open tibial fractures presenting acutely to four Major Trauma Centres (MTCs) in England with co-located plastic surgery services over a ten-month period. The incidence of deep infective complications was compared between patients who underwent initial surgery according to the new NICE guidance and those who did not. Patients warranting emergency surgery for severely contaminated injury, concomitant life-threatening injury and neurovascular compromise were excluded. Multi-variable logistic regression analysis was performed to assess the effect of timing of surgical debridement on development of deep infective complications. Results: 112 patients with 116 fractures were included. Six fractures (5.2%) developed deep infective complications. 38% (n = 44) underwent primary debridement within 12 h and 90% within 24 h. There was no significant difference in the incidence of major infective complications if debrided in less than or greater than 12 h (4.5% vs 5.6%, p = 1.00). Logistic regression found no significant relationship between timing of wound excision and development of deep infection. There was no significant decrease in mean time to debridement following introduction of new national guidance (13.6 vs 16.1 h) in these four MTCs. Conclusion: Overall, the rate of deep infection in high energy open tibial fractures managed within the four major trauma centes is low. Achieving surgical debridement within 12 h is challenging within the current infrastructure, and it is unclear whether adhering to this target will significantly affect the incidence of severe infective complications. Debridement within 24 h appears achievable. If a 12-h target is to be met, it is vital to ensure dedicated orthoplastic capacity is adequately resourced
The advantages of information management through building information modelling
This article was published in the journal, Construction Management [© Taylor & Francis] and the definitive version is available at: http://dx.doi.org/10.1080/01446193.2013.777754As building information modelling (BIM) is positioned by governments and construction professionals as a solution to the problems in the construction industry, research is needed into the benefits BIM actually confers. The focus here is on the effectiveness of BIM as a medium for communicating information within a construction team. A case study of an offsite precast concrete fabrication facility was conducted. At the time of the study, the facility was supplying precast units for four public sector projects, and using four information management systems: e-mail, a construction project extranet tool, an Enterprise Resource Planning system and a new BIM-based system. The flow of information through the four media was measured and visualized as the projects progressed. This quantitative measurement of information flow was combined with qualitative data from interviews with facility staff. It was found that the introduction of the BIM-based system diverted information flow through the building model and away from the extranet system. The use of e-mail was largely unaffected. BIM allowed considerably more accurate, on-time and appropriate exchange of information. It is concluded it is possible to quantify some of the benefits of BIM to information management. This research paves the way for future research into the management of more construction project information linked more closely to building models
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Risk Factors for Symptomatic Hyperlactatemia and Lactic Acidosis Among Combination Antiretroviral Therapy-Treated Adults in Botswana: Results from a Clinical Trial
Nucleoside analogue reverse transcriptase inhibitors are an integral component of combination antiretroviral treatment regimens. However, their ability to inhibit polymerase-γ has been associated with several mitochondrial toxicities, including potentially life-threatening lactic acidosis. A total of 650 antiretroviral-naive adults (69% female) initiated combination antiretroviral therapy (cART) and were intensively screened for toxicities including lactic acidosis as part of a 3-year clinical trial in Botswana. Patients were categorized as no lactic acidosis symptoms, minor symptoms but lactate <4.4 mmol/liter, and symptoms with lactate ≥ 4.4 mmol/liter [moderate to severe symptomatic hyperlactatemia (SH) or lactic acidosis (LA)]. Of 650 participants 111 (17.1%) developed symptoms and/or laboratory results suggestive of lactic acidosis and had a serum lactate drawn; 97 (87.4%) of these were female. There were 20 events, 13 having SH and 7 with LA; all 20 (100%) were female (p<0.001). Cox proportional hazard analysis limited to the 451 females revealed that having a higher baseline BMI was predictive for the development of SH/LA [aHR=1.17 per one-unit increase (1.08-1.25), p<0.0001]. Ordered logistic regression performed among all 650 patients revealed that having a lower baseline hemoglobin [aOR=1.28 per one-unit decrease (1.1-1.49), p=0.002] and being randomized to d4T/3TC-based cART [aOR=1.76 relative to ZDV/3TC (1.03-3.01), p=0.04] were predictive of the symptoms and/or the development of SH/LA. cART-treated women in sub-Saharan Africa, especially those having higher body mass indices, should receive additional monitoring for SH/LA. Women presently receiving d4T/3TC-based cART in such settings also warrant more intensive monitoring
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