High voltage solid-state relay

Hybrid microelectronics relay has characteristics significantly superior to conventional solid state relays. Relay provides 2500 Vdc input to output isolation and operates from high threshold logic signal to switch load of 400 Vdc at 2 mA. Technology should be of interest to manufacturers of discrete components

High Fidelity Chemistry And Radiation Modeling For Oxy-Combustion Scenarios

To account for the thermal and chemical effects associated with the high CO2 concentrations in an oxy-combustion atmosphere, several refined gas-phase chemistry and radiative property models have been formulated for laminar to highly turbulent systems. This thesis examines the accuracies of several chemistry and radiative property models employed in computational fluid dynamic (CFD) simulations of laminar to transitional oxy-methane diffusion flames by comparing their predictions against experimental data. Literature review about chemistry and radiation modeling in oxy-combustion atmospheres considered turbulent systems where the predictions are impacted by the interplay and accuracies of the turbulence, radiation and chemistry models. Thus, by considering a laminar system we minimize the impact of turbulence and the uncertainties associated with turbulence models. In the first section of this thesis, an assessment and validation of gray and non-gray formulations of a recently proposed weighted-sum-of-gray gas model in oxy-combustion scenarios was undertaken. Predictions of gas, wall temperatures and flame lengths were in good agreement with experimental measurements. The temperature and flame length predictions were not sensitive to the radiative property model employed. However, there were significant variations between the gray and non-gray model radiant fraction predictions with the variations in general increasing with decrease in Reynolds numbers possibly attributed to shorter flames and steeper temperature gradients. The results of this section confirm that non-gray model predictions of radiative heat fluxes are more accurate than gray model predictions especially at steeper temperature gradients. In the second section, the accuracies of three gas-phase chemistry models were assessed by comparing their predictions against experimental measurements of temperature, species concentrations and flame lengths. The chemistry was modeled employing the Eddy Dissipation Concept (EDC) employing a 41-step detailed chemistry mechanism, the non-adiabatic extension of the equilibrium Probability Density Function (PDF) based mixture-fraction model and a two-step global finite rate chemistry model with modified rate constants proposed to work well in oxy-methane flames. Based on the results from this section, the equilibrium PDF model in conjunction with a high-fidelity non-gray model for the radiative properties of the gas-phase may be deemed as accurate to capture the major gas species concentrations, temperatures and flame lengths in oxy-methane flames. The third section examines the variations in radiative transfer predictions due to the choice of chemistry and gas-phase radiative property models. The radiative properties were estimated employing four weighted-sum-of-gray-gases models (WSGGM) that were formulated employing different spectroscopic/model databases. An average variation of 14 - 17% in the wall incident radiative fluxes was observed between the EDC and equilibrium mixture fraction chemistry models, due to differences in their temperature predictions within the flame. One-dimensional, line-of-sight radiation calculations showed a 15 - 25 % reduction in the directional radiative fluxes at lower axial locations as a result of ignoring radiation from CO and CH4. Under the constraints of fixed temperature and species distributions, the flame radiant power estimates and average wall incident radiative fluxes varied by nearly 60% and 11% respectively among the different WSGG models

Coaxial carbon plasma gun deposition of amorphous carbon films

A unique plasma gun employing coaxial carbon electrodes was used in an attempt to deposit thin films of amorphous diamond-like carbon. A number of different structural, compositional, and electrical characterization techniques were used to characterize these films. These included scanning electron microscopy, scanning transmission electron microscopy, X ray diffraction and absorption, spectrographic analysis, energy dispersive spectroscopy, and selected area electron diffraction. Optical absorption and electrical resistivity measurements were also performed. The films were determined to be primarily amorphous, with poor adhesion to fused silica substrates. Many inclusions of particulates were found to be present as well. Analysis of these particulates revealed the presence of trace impurities, such as Fe and Cu, which were also found in the graphite electrode material. The electrodes were the source of these impurities. No evidence of diamond-like crystallite structure was found in any of the film samples. Details of the apparatus, experimental procedure, and film characteristics are presented

Neurospora tetraspora D. Garcia, Stchigel & Guarro (= Gelasinospora tetrasperma Dowding) as a first record to Egypt

An interesting isolate of homothallic, ascosporic filamentous fungus having 4-spored asci, was recovered once from a non-rhizosphere soil sample collected from a grapevine plantation in the village of El-Khawaled, Sahel-Saleem city, Assiut. It was isolated on DYM agar plate at 25°C in June 2008. The isolate was identified phenotypically and genotypically as Neurospora tetraspora (= Gelasinospora tetrasperma) and was deposited in the culture collection of Assiut University Mycological Centre as AUMC no. 6784 and ITS gene sequence of the strain was deposited at the National Center for Biotechnology Information (NCBI) and assigned a GenBank accession number JQ425383. N. tetraspora is being recorded in the current work for the first time in Egypt. By this addition, the genus is now known in Egypt by four species. A key is provided for the four species. DOI: http://dx.doi.org/10.5281/zenodo.116560

Danger signals, inflammasomes, and the intricate intracellular lives of chlamydiae

Chlamydiae are obligate intracellular bacterial pathogens, and as such are sensitive to alterations in the cellular physiology of their hosts. Chlamydial infections often cause pathologic consequences due to prolonged localized inflammation. Considerable advances have been made in the last few years regarding our understanding of how two key inflammation-associated signaling pathways influence the biology o

Mycological and enzymatic studies on fresh beef meat sold in Taiz City, Yemen

The mycological analysis of 30 fresh beef meat samples on Czapek’s agar at 7º and 28ºC revealed that, heavily contamination with moulds was observed especially at 28ºC. A total of 234 and 400 colonies ⁄ 450 g meat were collected on both temperatures, respectively. Sixty-seven species belonging to 20 genera were identified. Members of Aspergillus, Mucor, Penicillium and Trichoderma were the most prevalent fungi. At 7°C was highly spoilage by yeasts fungi, while filamentous fungi predominated at 28°C. The ability of the common fungal isolates to produce protease and lipase enzymes revealed that most of them were positive. Among 152 isolates tested, 103 (67.8%) and 96 (63.2%) could respectively produce these enzymes. Because the deteriorative effects of the above fungi, food should be frequently and routinely analyzed. Also, it is essential to store the meat at lower temperature immediately after slaughtering and during transport and storage to reduce or prevent mould growth. DOI: http://dx.doi.org/10.5281/zenodo.103723

The Evolving Role of TRAFs in Mediating Inflammatory Responses

TRAFs [tumor necrosis factor (TNF) receptor associated factors] are a family of signaling molecules that function downstream of multiple receptor signaling pathways and play a pivotal role in the biology of innate, and adaptive immune cells. Following receptor ligation, TRAFs generally function as adapter proteins to mediate the activation of intracellular signaling cascades. With the exception of TRAF1 that lacks a Ring domain, TRAFs have an E3 ubiquitin ligase activity which also contributes to their ability to activate downstream signaling pathways. TRAF-mediated signaling pathways culminate in the activation of several transcription factors, including nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs; e.g., ERK-1 and ERK-2, JNK, and p38), and interferon-regulatory factors (IRF; e.g., IRF3 and IRF7). The biological role of TRAFs is largely due to their ability to positively or negatively regulate canonical and non-canonical NF-κB signaling. While TRAF-mediated signaling regulates various immune cell functions, this review is focused on the recent advances in our knowledge regarding the molecular mechanisms through which TRAF proteins regulate, positively and negatively, inflammatory signaling pathways, including Toll–IL-1 receptors, RIG-I like receptors, and Nod-like receptors. The review also offers a perspective on the unanswered questions that need to be addressed to fully understand how TRAFs regulate inflammation