4,649 research outputs found
Diagnostics of accelerating plasma Semiannual progress report, 1 Sep. 1968 - 28 Feb. 1969
Accelerating plasma diagnostics - validity of local thermal equilibrium assumption in electromagnetic shock tubes, and current-sheet velocity in coaxial plasma accelerato
Diagnostics of accelerating plasma Semiannual progress report, 1 Mar. - 31 Aug. 1968
Plasma diagnostics in electromagnetically driven shock tubes using laser scattering methods as compared to spectroscopic technique
The Design of Control Strategy for Blended Series-Parallel Power-Split PHEV – a Simulation Study
Electric Vehicles (EVs) have been extensively researched to reduce the fuel consumption and
tailpipe emission. The series-parallel power-split Plug-in Electric Vehicle (PHEV) has been considered as one
of the most suitable candidates. It contains both an internal combustion engine (ICE) and an electrical storage
system (ESS) to achieve a better driving performance. The energy management system (EMS) is significant for
a PHEV to improve the efficiency of the whole system. Electric vehicle mode (EV), charging depletion (CD)
and charging sustaining (CS) modes will be discussed to build a control strategy in this study. This control
strategy will be implemented with the state of charge (SoC) to show its impact through a simulation study
AC and DC House Wiring Efficiency Estimations Using a Fast Extensive Measurements Approach
DC-based appliances are exponentially increasing in the present market. This scenario opens the opportunity to utilize the DC electricity produced by the PV panels directly without going through the conversion stages. Due to high penetration of DC electricity sources, it is timely to utilize DC electricity directly. Several research works have been reported in the literature to experimentally test and compare AC and DC wiring options. Accurate and precise experimental measurements are vital to establish a sound theoretical basis. However, this is difficult due to cost and time constraints. Therefore, to avoid costly measurements, this paper develops a mathematical model based on measurements on selected AC and DC wiring at four voltage levels (12 V DC, 24 V DC, 48 V DC, and 230 V AC). A digital simulation calibration using DigSilent is conducted to validate the proposed mathematical model. This paper proposed to utilize the simulation calibration approach that is a cost-effective and timesaving option to perform extensive measurements accurately
Diagnostics of accelerating plasma Semiannual progress report, 1 Sep. 1967 - 29 Feb. 1968
Current sheet velocities measured in coaxial plasma accelerators with and without refractory insulator lining
The Energy of a Plasma in the Classical Limit
When \lambda_{T} << d_{T}, where \lambda_{T} is the de Broglie wavelength and
d_{T}, the distance of closest approach of thermal electrons, a classical
analysis of the energy of a plasma can be made. In all the classical analysis
made until now, it was assumed that the frequency of the fluctuations \omega <<
T (k_{B}=\hbar=1). Using the fluctuation-dissipation theorem, we evaluate the
energy of a plasma, allowing the frequency of the fluctuations to be arbitrary.
We find that the energy density is appreciably larger than previously thought
for many interesting plasmas, such as the plasma of the Universe before the
recombination era.Comment: 10 pages, 2 figures, accepted for publication in Phys.Rev.Let
Conditional linearizability criteria for a system of third-order ordinary differential equations
We provide linearizability criteria for a class of systems of third-order
ordinary differential equations (ODEs) that is cubically semi-linear in the
first derivative, by differentiating a system of second-order quadratically
semi-linear ODEs and using the original system to replace the second
derivative. The procedure developed splits into two cases, those where the
coefficients are constant and those where they are variables. Both cases are
discussed and examples given
Therapeutic distant organ effects of regional hypothermia during mesenteric ischemia-reperfusion injury
IntroductionMesenteric ischemia-reperfusion injury (IRI) leads to systemic inflammation and multiple organ failure in clinical and laboratory settings. We investigated the lung structural, functional, and genomic response to mesenteric IRI with and without regional intraischemic hypothermia (RIH) in rodents and hypothesized that RIH would protect the lung and preferentially modulate the distant organ transcriptome under these conditions.MethodsSprague-Dawley rats underwent sham laparotomy or superior mesenteric artery occlusion (SMAO) for 60 minutes with or without RIH. Gut temperature was maintained at 15°-20°C during SMAO, and systemic normothermia (37°C) was maintained throughout the study period. At 6 or 24 hours, lung tissue was collected for (1) histology, (2) myeloperoxidase activity, (3) bronchoalveolar lavage (BAL) fluid protein concentrations, (4) lung wet/dry ratios, and (5) total RNA isolation and hybridization to Illumina's Sentrix BeadChips (>22,000 probes) for gene expression profiling. Significantly affected genes (false discovery rate <5% and fold change ≥1.5) were linked to gene ontology (GO) terms using MAPPFinder, and hypothermia-suppressed genes were further analyzed with Pubmatrix.ResultsMesenteric IRI-induced lung injury, as evidenced by leukocyte trafficking, alveolar hemorrhage, and increased BAL protein and wet/dry ratios, and activated a proinflammatory lung transcriptome compared with sham. In contrast, rats treated with RIH exhibited lung histology, BAL protein, and wet/dry ratios similar to sham. At 6 hours, GO analysis identified 232 hypothermia-suppressed genes related to inflammation, innate immune response, and cell adhesion, and 33 hypothermia-activated genes related to lipid and amine metabolism and defense response. Quantitative real-time polymerase chain reaction validated select array changes in top hypothermia-suppressed genes lipocalin-2 (lcn-2) and chemokine ligand 1 (CXCL-1), prominent genes associated with neutrophil activation and trafficking.ConclusionsTherapeutic hypothermia during SMAO provides distant organ protection and preferentially modulates the IRI-activated transcriptome in the rat lung. This study identifies potential novel diagnostic and therapeutic targets of mesenteric IRI and provides a platform for further mechanistic study of hypothermic protection at the cellular and subcellular level.Clinical RelevanceVisceral organ ischemia-reperfusion injury (IRI) is a common clinical problem in the settings of shock, sepsis, vascular surgery, and organ transplantation and is a particularly vexing problem in the repair of complex aortic aneurysms. IRI is associated with considerable patient morbidity and mortality, for which there are virtually no therapeutic options. It systematically causes local organ injury and dysfunction, systemic inflammation, and multiple organ failure. Clinical trials investigating the efficacy of pharmacologic blockade of individual downstream inflammatory mediators in critically ill patients have been largely unsuccessful, and such studies highlight the need for novel top-down approaches, such as gene expression profiling for biologic discovery, as well as application of broader therapeutic interventions, such as targeted hypothermia. In this study, we demonstrate the potential application of visceral cooling for distant organ protection during mesenteric IRI, identify broad changes in lung gene expression under these conditions, and have elucidated potential novel diagnostic and therapeutic targets for disease targeting
Deep learning based feature matching and its application in image orientation
Matching images containing large viewpoint and viewing direction changes, resulting in large perspective differences, still is a very challenging problem. Affine shape estimation, orientation assignment and feature description algorithms based on detected hand crafted features have shown to be error prone. In this paper, affine shape estimation, orientation assignment and description of local features is achieved through deep learning. Those three modules are trained based on loss functions optimizing the matching performance of input patch pairs. The trained descriptors are first evaluated on the Brown dataset (Brown et al., 2011), a standard descriptor performance benchmark. The whole pipeline is then tested on images of small blocks acquired with an aerial penta camera, to compute image orientation. The results show that learned features perform significantly better than alternatives based on hand crafted features. © 2020 Copernicus GmbH. All rights reserved
Caries experience by socio-behavioural characteristics in HIV-1-infected and uninfected Ugandan mothers – a multilevel analysis
Objectives
To assess caries experience in Ugandan mothers according to HIV status, socio-behavioural-characteristics, gingival bleeding status and to examine whether HIV status impacts the association of socio-behavioural characteristics with caries experience. Third, using multilevel analysis, this study assessed to what extent surface-specific caries experience varied between and within individuals.
Materials and methods
Caries experience was recorded using the World Health Organization’s Decayed, Missed and Filled Teeth/Surfaces indices from a cohort of 164 HIV-1-infected Ugandan mothers and a cross sectional comparison group of 181 negative controls. Mixed-effects logistic regression was conducted with surface-specific caries experience as the outcome variable.
Results
The prevalence of caries in HIV-1-infected and uninfected mothers was 81% and 71%, respectively. Significant associations occurred between caries experience at surface level and women’s increasing age (odds ratio [OR] = 1.8, 95% confidence interval [CI]: 1.1–2.8) and presence of gingival bleeding (OR = 2.0, 95% CI: 1.2–3.2). Intra-class correlation (ICC) coefficient amounted to 0.54 (95% CI 0.48‒0.59).
Conclusions
Caries prevalence was higher in HIV-1 infected than in uninfected mothers and increased with age and gingival bleeding. ICC indicated that 54% of the variance was attributable to variation between individuals. Socio-demographic differences in dental caries did not vary by HIV-1 status.publishedVersio
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