2,149 research outputs found

    Combustor flame flashback

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    Flashback, a problem that occurs in premixed-prevaporized combustors, is the upstream propagation of the flame from the combustor into the premixing tubes. Not only does flashback change the combustion process from premixed burning to diffusion burning, thus creating more pollutants, but it also inflicts considerable damage to the fuel injector, premixing tube and other equipment upstream. The conditions at which flashback occurs in steady burning and the mechanism that causes flashback in both steady and transient flow are studied. The equivalence ratio at which flashback occurs is being measured for inlet temperatures of 600-950 K, premixer wall temperatures of 450-1050 K and premixer velocities of 40-80 ft/s. These data are presented

    Global action-angle coordinates for completely integrable systems with noncompact invariant submanifolds

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    The obstruction to the existence of global action-angle coordinates of Abelian and noncommutative (non-Abelian) completely integrable systems with compact invariant submanifolds has been studied. We extend this analysis to the case of noncompact invariant submanifolds.Comment: 13 pages, to be published in J. Math. Phys. (2007

    Fermented Was Reported to Have Different Physicochemical and Functional Properties to Those of Non Fermented Flour. the Objective of This Research Was to Study the Effect of Spontaneous Fermentation to Chemical and Rheological Properties of Corn Flour and to Identifying Correlation Among Parameters. Flour Was Prepared by Spontaneous Fermentation with Variation of Fermentation TIME (0, 12, 24, 36, 48, 60 and 72 Hours). the Result Indicated That the Increasing of Corn Grits Fermentation TIME Was Decrease of Protein, Crude Fiber, Lipid, Ash, Starch and Amylase Content of Corn Flour. the Increasing of Protein Content, Reduction Sugar, Crude Fiber, Ash, Bulk Density and Gelatinization TIME Were Decrease of Gel Strength. Gel Strength Will Be Promote with Increasing of Angle of Repose and Peak Viscosity. Gel Stickeness Will Decrease with Increasing of Amylosa: Amylopecyin Ratio and Breakdown Viscosity. Key Words: White Corn, Flour,fermentation, Chemical, Rheological

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    Fermented was reported to have different physicochemical and functional properties to those of non fermented flour. The objective of this research was to study the effect of spontaneous fermentation to chemical and rheological properties of corn flour and to identifying correlation among parameters. Flour was prepared by spontaneous fermentation with variation of fermentation time (0, 12, 24, 36, 48, 60 and 72 hours). The result indicated that the increasing of corn grits fermentation time was decrease of protein, crude fiber, lipid, ash, starch and amylase content of corn flour. The increasing of protein content, reduction sugar, crude fiber, ash, bulk density and gelatinization time were decrease of gel strength. Gel strength will be promote with increasing of angle of repose and peak viscosity. Gel stickeness will decrease with increasing of amylosa: amylopecyin ratio and breakdown viscosity

    Race affects SVR12 in a large and ethnically diverse hepatitis C-infected patient population following treatment with direct-acting antivirals: Analysis of a single-center Department of Veterans Affairs cohort.

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    Hepatitis C virus (HCV) infection is a major cause of chronic liver disease. HCV cure has been linked to improved patient outcomes. In the era of direct-acting antivirals (DAAs), HCV cure has become the goal, as defined by sustained virological response 12 weeks (SVR12) after completion of therapy. Historically, African-Americans have had lower SVR12 rates compared to White people in the interferon era, which had been attributed to the high prevalence of non-CC interleukin 28B (IL28B) type. Less is known about the association between race/ethnicity and SVR12 in DAA-treated era. The aim of the study is to evaluate the predictors of SVR12 in a diverse, single-center Veterans Affairs population. We conducted a retrospective study of patients undergoing HCV therapy with DAAs from 2014 to 2016 at the VA Greater Los Angeles Healthcare System. We performed a multivariable logistic regression analysis to determine predictors of SVR12, adjusting for age, HCV genotype, DAA regimen and duration, human immunodeficiency virus (HIV) status, fibrosis, nonalcoholic fatty liver disease (NAFLD) fibrosis score, homelessness, mental health, and adherence. Our cohort included 1068 patients, out of which 401 (37.5%) were White people and 400 (37.5%) were African-American. Genotype 1 was the most common genotype (83.9%, N = 896). In the adjusted models, race/ethnicity and the presence of fibrosis were statistically significant predictors of non-SVR. African-Americans had 57% lower odds for reaching SVR12 (adj.OR = 0.43, 95% CI = 1.5-4.1) compared to White people. Advanced fibrosis (adj.OR = 0.40, 95% CI = 0.26-0.68) was also a significant predictor of non-SVR. In a single-center VA population on DAAs, African-Americans were less likely than White people to reach SVR12 when adjusting for covariates

    Pemodelan Interaksi Serium(III) Dan Air Dengan Teori Perhitungan Ab Initio Serta Penentuan Himpunan Fungsi Basisnya

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    Penentuan himpunan fungsi basis (HFB) untuk simulasi ion Ce3+dalam air telah dilakukan dalampenelitian ini. Penentuan HFB harus dilakukan karena HFB yang tersedia adalah HFB untuk unsurCe(III), sedangkan model sistem kimia yang dikaji dalam penelitian ini adalah Ce dalam bentuk ion(Ce3+). Penentuan HFB dimulai dengan menerapkan semua HFB Ce yang diusulkan dari web basisset. Pemilihan HFB dilakukan dengan menggunakan dua metode. Pertama, mencocokkan kurvaenergi interaksi terhadap jarak dengan kurva potensial interaksi dua partikel Lennard-Jones 6-12(metode scan 2 body). Ke dua, optimasi struktur kompleks [Ce(H2O)n]3+ kemudian dibandingkandengan data eksperimen (metode water cluster). Tidak ada transfer muatan yang terjadi padainteraksi Ce3+ dengan air. HFB H dan O ditetapkan menggunakan DZP Dunning. Jenis simulasiDinamika Molekuler yang direkomendasikan untuk mengkaji ion Ce3+ di dalam air adalah MK/MMdengan menggunakan HFB Stutgard RSC ANO/ECP dan Quantum Mechanical Charge Field(QMCF) dengan menggunakan HFB SBKJC VDZ ECP pada tingkat teori Hartree-Fock (HF)

    Dielectric multilayer waveguides for TE and TM mode matching

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    We analyse theoretically for the first time to our knowledge the perfect phase matching of guided TE and TM modes with a multilayer waveguide composed of linear isotropic dielectric materials. Alongside strict investigation into dispersion relations for multilayer systems, we give an explicit qualitative explanation for the phenomenon of mode matching on the basis of the standard one-dimensional homogenization technique, and discuss the minimum number of layers and the refractive index profile for the proposed device scheme. Direct applications of the scheme include polarization-insensitive, intermodal dispersion-free planar propagation, efficient fibre-to-planar waveguide coupling and, potentially, mode filtering. As a self-sufficient result, we present compact analytical expressions for the mode dispersion in a finite, N-period, three-layer dielectric superlattice.Comment: 13 pages with figure

    Electron irradiation induced reduction of the permittivity in chalcogenide glass (As2S3) thin film

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    We investigate the effect of electron beam irradiation on the dielectric properties of As2S3 Chalcogenide glass. By means of low-loss Electron Energy Loss Spectroscopy, we derive the permittivity function, its dispersive relation, and calculate the refractive index and absorption coefficients under the constant permeability approximation. The measured and calculated results show, to the best of our knowledge, a heretofore unseen phenomenon: the reduction in the permittivity of <40%, and consequently a modification of the refractive index follows, reducing it by 20%, hence suggesting a significant change on the optical properties of the material. The plausible physical phenomena leading to these observations are discussed in terms of the homopolar and heteropolar bond dynamics under high energy absorption.Comment: 22 pages, 7 figures, manuscript in preparation to send to Physical Review

    Resonant Photon-Assisted Tunneling Through a Double Quantum Dot: An Electron Pump From Spatial Rabi Oscillations

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    The time average of the fully nonlinear current through a double quantum dot, subject to an arbitrary combination of ac and dc voltages, is calculated exactly using the Keldysh nonequilibrium Green function technique. When driven on resonance, the system functions as an efficient electron pump due to Rabi oscillation between the dots. The pumping current is maximum when the coupling to the leads equals the Rabi frequency.Comment: 6 pages, REVTEX 3.0, 3 postscript figure

    Enhancing Business Performance Of CV. Jati Makmur Pasuruan Using E-brochure Marketing Strategy

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    This report provides an analysis and evaluation of CV Jati Makmur in entering the new market. CV. Jati Makmur is a plywood industry operating more than 15 years in producing woodworking, aiming to grasp the International market for expansion. There are various analysis methods included in the observation. These methods of analysis include Segmenting, Targeting, and Positioning. To conquer the market share in China and Japan as well to increase economic competitiveness several recommended strategies in incorporated. This strategy involves pricing strategy distribution and promotion strategy. In addition, this report also observes the fact that the analysis contains some limitations as well as risks. These risks include external factors such as Government, Competition, and Technology that will affect the future development of CV. Jati Makmur. This report finds the prospects for CV. Jati Makmur in its current position is positive. The major area of weakness requires further investigation and remedial action by management
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