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Use　of　Computational　Fluid　Dynamics　to　Simulate　the　Effects　of　Design　and　Operating　Parameters　on　the　Overall　Performance

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journal of Thermal Science 1995年第4期4卷 250-257页

作者： v.Nasserzadeh j.Swithenbank DepartmentofMechanical＆ProcessEngineering SheffieldUniversitySheffield.UK DepartmentofMechanical＆Pro

With around 10 tonnes of waste being generated for every maul woman and child each year across the globe, safe disposal of it all has become an urgent environmental problem. In 1993, Western Europe,the United States, Canada, japan, Australia and New Zealand produced a total of 480 millon tonnes of industrial waste and & billion tonnes from activities such as energy production, agriculture, mining and sewage disposal. The emission to the atmosphere of both heavy metals and acid gases and perhaps more important in the longer term, the Dioxins/Furans (PCDDs/PCDFs), promises to be one of the key issues facing not only the industry but the society as a whole over the next decade and *** it is increasingly likely that measures to control toxic emissions will have to be directed at a wider target than just the waste incinerators, it is equally certain that both public opinion and legislation will, at least in the first instance, see the incinerators as one of the most obvious candidates for tighter *** days, virtually all the new research and development techniques in combustion technology involve the application of computational fluid dynamics (CFD) to combustor design. This seems to be the best approach to solving design problems. Mathematical modelling thus is seen as an inherent part *** all combustion research programmes. The new discipline of computational fluid dynamics can also be used to help minimize flame generated pollutants released to the atmosphere. These pollutants include; CO2, CO, SO2, NOx, HC1, Hydrocarbons, soot, particulates, heavy metals and dioxins/furans. CFD studies of their release to the atmosphere must include not only their source in the flame, but also their removal from the fine gases by scrubbing and other techniques. The governing differential equations for the process being studied must be defined and solved simultaneously if the parameters in the equations are interacting. At present, this procedure can g

关键词： toxic emissions waste incineration CFD modelling.

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Scaling Regimes and the Singularity of Specific Heat in the 3D Ising Model

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Communications in Computational Physics 2013年第7期14卷 355-369页

作者： j.Kaupuzs R.v.N.Melnik j.Rimsans Institute of Mathematics and Computer Science University of Latvia29 Rai¸na BoulevardLV1459RigaLatvia Institute of Mathematical Sciences and Information Technologies University of Liepaja14 Liela StreetLiepaja LV-3401Latvia Wilfrid Laurier University WaterlooOntarioCanadaN2L 3C5

The singularity of specific heat Cv of the three-dimensional Ising model is studied based on Monte Carlo data for lattice sizes L≤*** of two data sets,one corresponding to certain value of the Binder cumulant and the other-to the maximum of Cv,provide consistent values of C0 in the ansatz Cv(L)=C0+AL^(a/n) at large L,if a/n=0.196(6).However,a direct estimation from our Cmax v data suggests that a/n,most probably,has a smaller value(e.g.,a/n=0.113(30)).Thus,the conventional power-law scaling ansatz can be questioned because of this *** have found that the data are well described by certain logarithmic ansatz.

关键词： Ising model Monte Carlo simulation specific heat finite-size scaling critical exponents

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Correlation Functions, Universal Ratios and Goldstone Mode Singularities in n-vector Models

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Communications in Computational Physics 2014年第5期15卷 1407-1430页

Correlation functions in the O(n)models below the critical temperature are *** on Monte Carlo(MC)data,we confirm the fact stated earlier by Engels and vogt,that the transverse two-plane correlation function of the O(4)model for lattice sizes about L=120 and small external fields h is very well described by a Gaussian ***,we show that fits of not lower quality are provided by certain non-Gaussian *** have also tested larger lattice sizes,up to L=*** Fourier-transformed transverse and longitudinal two-point correlation functions have Goldstone mode singularities in the thermodynamic limit at k→0 and h=+0,i.e.,G_(⊥)(k)≈ak−λ_(⊥)and G_(||)(k)≈bk−λk,*** a and b are the amplitudes,k=|k|is the magnitude of the wave vector *** exponentsλ_(⊥),λk and the ratio bM^(2)/a^(2),where M is the spontaneous magnetization,are universal according to the GFD(grouping of Feynman diagrams)*** we find that the universality follows also from the standard(Gaussian)theory,yielding bM^(2)/a^(2)=(n−1)/*** MC estimates of this ratio are 0.06±0.01 for n=2,0.17±0.01 for n=4 and 0.498±0.010 for n=*** to these and our earlier MC results,the asymptotic behavior and Goldstone mode singularities are not exactly described by the standard *** is expected from the GFD *** have found appropriate analytic approximations for G_(⊥)(k)and G_(||)(k),well fitting the simulation data for small *** have used them to test the Patashinski-Pokrovski relation and have found that it holds approximately。

关键词： n-component vector models correlation functions Monte Carlo simulation Goldstone mode singularities.

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Isolation and identification of MDR-Mycobacterium tuberculosis and screening of partially characterised antimycobacterial compounds from chosen marine micro algae

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Asian Pacific journal of Tropical Medicine 2010年第8期3卷 655-661页

作者： Prakash S Sasikala SL Aldous v Huxley j Department of Biotechnology Udaya School of Engineering.K.K.Dist.Tamil Nadu.India Centre for Marine Science and Technology Manonmaniam Sundaranar UniversityRajakkamangalamK.K.Dist.Tamil NaduIndia Department of Zoology Thiru.Vi.Ka.Government Arts CollegeThiruvarur.Tamil NaduIndia

Objective:To isolate the multiple drug resistance(MDR) Mycobacterium tuberculosis(M. tuberculosis) and to screen for the bioactive compounds extracted from marine microalgae. Methods:Sixty seven collected samples that were confirmed by 16S rDNA analysis as positive with *** infection were subjected to sensitivity test against commercially used front line and second line drugs by absolute concentration method using Lj *** bacterial isolates numbered I-78,I-101,I-127,I-173,I-202,I-262,I-327 showed resistant for more than 3 drugs were considered as MDR *** the percentage of 10.4 were recorded MDR-TB. Fifteen marine micro algal extracts were screened for antimycobacterial activity and partial characterization of the active principles was ***:The percentage contribution of marine micro algal species on the extraction of antimycobacterials indicated Isochrysis galbana(I. galbana) contain rich bioactive compounds and accounted for 60%inhibition of the total isolates. The percentage contribution of solvents on the extraction of antimicrobials from *** showed that the methanol,chloroform,n-Butanol showed maximum of *** purified eluted compounds(R,0.43) from TLC plate were chromatographed by gas *** eluted sterol compounds showed 13 unsaturated sterols with 3 major ***:The present study indicates the presence of unsaturated fatty acids may have the effect on MDR M. tuberculosis,indicating a potential natural alternative to antibiotics.

关键词： Antimycobacterials Marine micro algae Mycobacterium tuberculosis

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Dexamethasone in coronavirus disease 2019 care:Dosage and utilization insights

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World journal of virology 2025年第1期14卷 1-4页

作者： Laiba Shamim Imshaal Musharaf Abdulqadir j Nashwan Department of Clinical Medicine Jinnah Sindh Medical UniversityKarachi 75510SindhPakistan Department of Medicine Jinnah Sindh Medical UniversityKarachi 75510SindhPakistan Department of Nursing and Midwifery Research Hamad Medical CorporationDoha 3050Qatar

Coronavirus disease 2019(COvID-19)is a contagious disease caused by severe acute respiratory syndrome coronavirus *** was declared a global pandemic on March 11,2020,by the World Health *** excessive inflammatory response is a severe respiratory manifestation of COvID-19,which becomes predominant in later *** to its immunosuppressive and anti-inflammatory properties,dexamethasone is the first systemic glucocorticoid to treat severe COvID-19 *** editorial reviews the efficacy and safety of highdose vs low-dose dexamethasone in patients with *** indicate that using low-dose dexamethasone is beneficial and emphasize the need for additional research on the use of high-dose *** the study provides a robust evidence base,it is limited by the lack of long-term data,focus on specific outcomes and heterogeneity of the included *** research should focus on the long-term effects of dexamethasone and its impact across varying disease severities and patient populations to refine treatment strategies and improve patient care.

关键词： COvID-19 Severe acute respiratory syndrome Corticosteroid Dexamethasone Anti-inflammatory

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Current treatment indications and strategies in chronic hepatitis B virus infection

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World journal of Gastroenterology 2008年第45期14卷 6902-6910页

作者： George v Papatheodoridis Spilios Manolakopoulos Athanasios j Archimandritis 2nd Department of Internal Medicine Athens University School of Medicine Hippokration General Hospital of Athens

The optimal approach to the management of several marginal cases with chronic hepatitis B virus (HBv) infection is controversial. Serum HBv DNA and ami-notransferase levels, and the degree of necroinflammation and fibrosis determine the therapeutic decisions. All patients with elevated aminotransferase (> twice the upper limit of normal) and serum HBv DNA above 20 000 IU/mL should be treated. Liver biopsy is important for therapeutic decisions in cases with mild aminotransferase elevations and serum HBv DNA below 20 000 IU/mL. Chronic HBv patients who do not receive treatment should be followed for life. There are seven agents licensed for chronic hepatitis B: standard and pegylated interferon-alpha, lamivudine, adefovir, entecavir, telbivudine and tenofovir. One-year courses with pegylated interferon-alpha induce sustained off-therapy remission in 30%-32% of patients with HBeAg-positive chronic hepatitis B and in a smaller proportion of patients with HBeAg-negative chronic hepatitis B. Oral antivirals achieve initial on-therapy responses in the majority of patients, but are intended as long-term therapies. viral suppression has favourable effects on patients' outcome and modifies the natural course of the disease. viral resistance, however, is the major drawback of long-term oral antiviral therapy. Lamivudine monotherapy is associated with the highest and ente-cavir monotherapy with the lowest resistance rate so far. There has been no resistance to tenofovir, but afteronly 18 mo of treatment to date. The optimal first-line anti-HBv therapy with the best long-term cost/benefit ratio remains unclear. If oral antiviral agents are used, compliance should always be ascertained and HBv DNA levels should be regularly tested.

关键词： Hepatitis B Hepatitis B virus DNA Interferon Antivirals Resistance

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MODELING HEADCUT DEvELOPMENT AND MIGRATION IN UPLAND CONCENTRATED FLOWS

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International journal of Sediment Research 2005年第4期20卷 281-294页

作者： Sean j. BENNETT Carlos v. ALONSO Department of Geography University at Buffalo Buffalo NY 14261-0055 USA USDA-ARS National Sedimentation Laboratory P.O. Box 1157 Oxford MS 38655

On hillslopes and agricultural fields, discrete areas of intense, localized soil erosion commonly take place in the form of migrating headcuts. These erosional features significantly increase soil loss and landscape degradation, yet the unsteady, transient, and migratory habits of headcuts complicate their phenomenological and erosional characterization. Here a unique experimental facility was constructed to examine actively migrating headcuts typical of upland concentrated flows. Essential components of the facility include a deep soil cavity with external drainage, rainfall simulator, capacity for overland flow, and a video recording technique for data collection. Results from these experiments show that: (1) after a short period of adjustment, headcut migration attained a steady-state condition, where the rate of migration, scour hole geometry, and sediment discharge remain constant with time; (2) boundary conditions of higher rates of overland flow, steeper bed slopes, and larger initial headcut heights produced systematically larger scour holes with higher rates of soil erosion; and (3) during migration, the turbulent flow structure within the scour hole remained unchanged, consisting of an overfall nappe at the brink transitioning into a reattached wall jet with two recirculation eddies within the plunge pool. The systematic behavior of headcut development and migration enabled the application of modified jet impingement theory to predict with good success the characteristics of the impinging jet, the depth of maximum scour, the rate of headcut migration, and the rate of sediment erosion. These laboratory data and the analytical formulation can be used in conjunction with soil erosion prediction technology to improve the management of agricultural areas impacted by headcut development and ephemeral gully erosion.

关键词： Soil erosion Headcuts Rills Gullies jet impingement

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Two-Stage Negative Adaptive Cluster Sampling

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Communications in Mathematics and Statistics 2020年第1期8卷 1-21页

作者： R.v.Latpate j.K.Kshirsagar Department of Statistics and Centre for Advanced Studies Savitribai Phule Pune UniversityPuneIndia Department of Statistics NAC&S CollegeAhmednagarIndia

If the population is rare and clustered,then simple random sampling gives a poor estimate of the population *** such type of populations,adaptive cluster sampling is *** it loses control on the final sample ***,the cost of sampling increases *** overcome this problem,the surveyors often use auxiliary information which is easy to obtain and *** attempt is made through the auxiliary information to control the final sample *** this article,we have proposed two-stage negative adaptive cluster sampling *** is a new design,which is a combination of two-stage sampling and negative adaptive cluster sampling *** this design,we consider an auxiliary variablewhich is highly negatively correlatedwith the variable of interest and auxiliary information is completely *** the first stage of this design,an initial random sample is drawn by using the auxiliary ***,using Thompson’s(jAmStat Assoc 85:1050-1059,1990)adaptive procedure networks in the population are *** networks serve as the primary-stage units(PSUs).In the second stage,random samples of unequal sizes are drawn from the PSUs to get the secondary-stage units(SSUs).The values of the auxiliary variable and the variable of interest are recorded for these *** estimator is proposed to estimate the population total of the variable of interest.A new estimator,Composite Horwitz-Thompson(CHT)-type estimator,is also *** is based on only the information on the variable of *** of the above two estimators along with their unbiased estimators are *** this proposed methodology,sample survey was conducted at Western Ghat of Maharashtra,*** comparison of the performance of these estimators and methodology is presented and compared with other existing *** cost-benefit analysis is given.

关键词： Adaptive cluster sampling Two-stage cluster sampling Negative adaptive cluster sampling Two-stage NACS Regression estimator

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Ev charging station with cascaded low-pass filtering scheme-based control of unified power quality conditioner

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Clean Energy 2022年第5期6卷 738-761页

作者： Arpitkumar j.Patel Amit v.Sant Department of Electrical Engineering School of TechnologyPandit Deendayal Energy UniversityGandhinagarGujaratIndia

This paper proposes a cascaded low-pass filter(CLPF)scheme for the control of a unified power quality conditioner(UPQC)installed for enhancing the power quality of an electric vehicle(Ev)charging *** the incorporation of UPQC,the Ev charging station draws sinusoidal currents at unity power factor and the supply voltage is maintained at the nominal value at the charger *** the CLPF scheme,theα-βcomponents of the load current are individually processed through a cascade connection of two LPFs to determine the corresponding fundamental orthogonal *** on thus determined components,the instantaneous and peak value and phase angle of the fundamental positive sequence component(FPSC)of the load current are ***,the corresponding quantities related to the load and supply voltages are also computed with the CLPF *** the computations related to the load current and supply voltage,the unit voltage templates(UvTs),power factor and fundamental active component(FAC)of the load current are *** the control of shunt compensation,reference currents are generated based on the FAC of the load current and ***,the control of series compensation is employed with the help of UvTs and peak amplitude of the FPSC of the load *** performance of CLPF scheme-based extraction is compared with that of the earlier reported schemes through simulation and experimental *** performance comparison reveals a faster dynamic and more accurate steady-state response with the proposed *** performance analysis of the proposed CLPF scheme-based control of a UPQC deployed at the Ev charging station for different operating conditions demonstrates station operation with requisite reactive power compensation and mitigation of voltage sag/swell,and prevention of propagation of harmonic and unbalanced currents into the *** results in increased reliability of charger operation,energy savings and increased efficiency o

关键词： battery chargers custom power devices electric vehicles power quality enhancement unified power quality conditioner

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Analytical and numerical modeling for the effects of thermal insulation in underground tunnels

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International journal of Mining Science and Technology 2016年第2期26卷 267-276页

作者： Liu W.v. Apel D.B. Bindiganavile v.S. Szymanski j.K. Department of Civil and Environmental Engineering University of Alberta

The heat How generated from the infinite rock mass surrounding the underground tunnels is a major cause for the increasing cooling demands in deep mine *** layers with lower thermal conductivities on tunnel walls and roof ceilings are believed to supply a thermo-barrier for heat ***,it is found that no systematic theoretical investigations were made to predict and confirm the effectiveness of underground thermal ***,investigations on the underground insulation problems involving heat flows through the semi-infinite hot rock mass and insulation layer were not ***,in this paper,the thermal characteristics,accompanied with heat flow through the semi-infinite rock mass and the insulation layer,were modeled by both analytical and numerical methods with focus on underground mine *** close agreements between models have indicated that the thermal insulation applied on tunnel surfaces is able to provide promising heat abatement effects.

关键词： Thermal insulation Theoretical models Underground Rock mass Heat abatement

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