检索结果-南通市图书馆

Optimization of the fuel rod＇s arrangement cooled by turbulentnanofluids flow in pressurized water reactor (PWR)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2017年第6期25卷 722-731页

作者： m. Hatami mJ.Z. Ganfi i. Sohrabiasl d. Jing international Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'anJiaotong University Xi'an 710049 China department of mechanical Engineering Esfarayen University of Technology Esfarayen North Khorasan lran department of Renewable Energies Engineering Faculty of New Sdences & Technologies University of Tehran Tehran lran department of mechanical Engineering Babol University of Technology Babol lran

in this paper, response surface methodology(RSm) based on central composite design(CCd) is applied to obtain an optimization design for the fuel rod's diameter and distance cooled by turbulent Al_2O_3–water nanofluid for a typical pressurized water reactor(PWR). Fuel rods and nanofluid flow between them are simulated 3d using computational fluid dynamics(CFd) by ANSYS-FLUNET package software. The RNG k–ε model is used to simulate turbulent nanofluid flow between the rods. The effect of different nanoparticles concentration is also investigated on the Nusselt number from heat transfer efficiency view point. Results reveal that when distance parameter(a) is in the minimum level and diameter parameter(r) is in the maximum possible level, cooling the rods will be better due to higher Nusselt number in this situation. Also, using the different nanoparticles on the cooling process confirms that Al_2O_3 averagely 17% and TiO_2 10% improve the Nusselt numbers.

关键词： Optimization Fuel rods Nanofluid Pressurized water reactor

morphology,structure and magnetic behavior of orthorhombic and hexagonal HoFeO_(3)synthesized via solution combustion approach

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第2期40卷 296-301,I0004页

作者： K.d.martinson i.S.Kondrashkova m.i.Chebanenko A.S.Kiselev T.Yu Kiseleva V.i.Popkov ioffe institute 26 PoliteknicheskayaSL Petersburg194021Russia Saint Petersburg State institute of Technology 26 MoskovskySt.Petersburg190013Russia Faculty of Physics M.V.Lomonosov State UniversityLeninskie CoryMoscow119991Russia

Nanostructured HoFeO_(3)powders were obtained by solution combustion method at various glycinenitrate ratios(G/N=0.2,0.4,...,1.4).According to X-ray powder diffractometry data,the presence of two modifications of HoFeO_(3)in the synthesized samples was established:orthorhombic(Pbnm)and hexagonal(P63/mmc).The crystallite size of the obtained compositions varies from 62±6 to 29±3 nm,depending on the G/N *** magnetic structure studies,it is found that HoFeO_(3)obtained with a stoichiometric amount of glycine in the reaction solution is in the magnetically ordered state and is represented by a sextet with quadrupole splitting(QS)=0 mm/s,isomeric shift(iS)=0.36 mm/s and effective field strength(Heff)=497 *** to the results of vibrational magnetometry,it is found that the orthoferrites obtained have a ferromagnetic structure,the main parameters of which(ms,mr and Hc)systematically change with a change in the redox ratio of the reaction mixture and,as a consequence,their phase composition,and reach maximum values at a G/N ratio=*** the samples obtained with a significant excess and lack of glycine(G/N=0.2 and 1.4),despite their amorphous nature,hysteresis loops characteristic of the ferromagnetic state of the substance is *** is hopeful to obtain a pure hexagonal modification of HoFeO_(3)via heat treatment on amorphous products of glycine-nitrate combustion.

关键词： Crystal structure Rare earth compounds Perovskites Nanomaterials magnetic materials

mechanical and Electrical Properties of the Ternary Ag-Sb-Zn System

在线全文

学校读者我要写书评

暂无评论

Acta metallurgica Sinica(English Letters) 2014年第1期27卷 47-54页

作者： m.Premovi d.mini d.manasijevi Vladan osovi d.Zivkovi i.dervisevi N.Talijan Faculty of Technical Science University in PristinaKosovska MitrovicaSerbia Technical Faculty University of Belgrade institute of Chemistry Technology and MetallurgyUniversity of Belgrade

This paper presents comparative review of experimental and thermodynamic assessment of ternary Ag-Sb-Zn system. isothermal section of the Ag-Sb-Zn system at 300 ~C has been calculated by CALPHAd method using ther- modynamic parameters from literature. microstructural analysis of a number of alloys was carried out by scanning electron microscopy and optical microscopy, whereas chemical composition of observed phases was analyzed using energy- dispersive X-ray spectroscopy. Hardness of selected alloys from four vertical sections was determined using Brinell hardness test and additionally by micro Vickers hardness test. Electrical conductivity of a number of alloys in the ternary Ag-Sb-Zn system was experimentally determined. Good overall agreement between experimental and calculated values was obtained.

关键词： Ag-Sb-Zn system isothermal section microstructure Brinell hardness micro Vickers hardness: Electrical conductivitv

Activated Sericite:An Efficient and Effective Natural Clay material for Attenuation of Cesium from Aquatic Environment

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2014年第6期24卷 731-742页

作者： d.TiWARi LALHmUNSiAmA S.i.CHOi S.m.LEE department of Chemistry School of Physical SciencesMizoram University department of Health and Environment Kwandong University department of Environmental Engineering Kwangwoon University

Sericite is mica-based natural clay that is annealed at 800 ℃ for 4 h, followed by acid activation using 3.0 mol L-1HCl at 100℃. The interaction of cesium(i), Cs(i), with sericite could provide useful data for the study of soil erosion or mass water movement utilizing the natural radioactive Cs. in this study sericite and activated sericite were used to assess their suitability in the attenuation of Cs from the aquatic environment under both batch and column experiments. The surface morphological studies indicated that a disordered and heterogeneous surface structure was exhibited by the activated sericite, whereas the native sericite exhibited a compact and layered structure. The Brunauer-Emmett-Teller(BET) specific surface area results indicated a significant increase in the surface area due to the activation of sericite. The batch reactor data collected for various parametric studies revealed that an increase in p H(from 2.0 to 8.0) and sorbate concentration(from 10.0 to 100.0 mg L-1) apparently favored the attenuation of Cs(i). The timedependent sorption data revealed that Cs(i) uptake was very rapid, and it achieved its saturation value within just 50 min of *** kinetic modeling studies indicated that the uptake of Cs(i) followed a pseudo-second-order rate equation; hence, the attenuation capacity of these solids for Cs(i) was estimated to be 0.858 and 4.353 mg g-1for sericite and activated sericite solids, *** adsorption isotherm modeling data showed a reasonably good applicability of the Freundlich model than the Langmuir *** effect of background electrolyte concentrations(0.001 to 0.1 mol L-1) of mg(NO3)2indicated that the presence of this electrolyte could not significantly affect the percent removal of Cs(i) by activated sericite. Furthermore, the fixed-bed column reactor operations were performed to obtain the breakthrough data, which were fitted well to the Thomas non-linear equation. Therefore, the loading capacity of Cs(i) wa

关键词： adsorption isotherms breakthrough data electrolyte kinetics radionuclide

Exact solutions for unsteady flow of second grade fluid generated by oscillating wall with transpiration

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2014年第7期35卷 821-830页

作者： m.ABdULHAmEEd i.KHAN d.ViERU S.SHAFiE department of mathematical Sciences Faculty of ScienceUniversiti Teknologi Malaysia Skudai 81310 Malaysia department of Theoretical mechanics Technical University of Iasi Iasi R-6600 Romania

A problem of unsteady flow of a second grade fluid over flat plates with the impulsive and oscillating motion, starting from rest, and with the wall transpiration is considered. The exact solutions are derived by the Laplace transform, the perturbation techniques, and an extension of the variable separation technique together with similarity arguments. These solutions are written as the sum between the permanent solutions and the transient solutions. The variations of fluid behaviors with various physical parameters are shown graphically and analyzed. The results are validated by comparing the limiting cases of the present paper with the results of the related published articles.

关键词： Stokes' problem second grade fluid wall transpiration oscillating wall

Laryngopharyngeal reflux and Helicobacter pylori

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第27期20卷 8964-8970页

作者： Taner Yllmaz münir demir Bajin Rlza nder Günayd?n Serdar zer Tevfik Szen department of Otolaryngology Head and Neck Surgery Hacettepe University Hospital

Laryngopharyngeal reflux(LPR) occurs when gastric contents pass the upper esophageal sphincter, causing symptoms such as hoarseness, sore throat, coughing, excess throat mucus, and globus. The pattern of reflux is different in LPR and gastroesophageal reflux. LPR usually occurs during the daytime in the upright position whereas gastroesophageal reflux disease more often occurs in the supine position at night-time or during sleep. Ambulatory 24-h double pH-probe monitoring is the gold standard diagnostic tool for LPR. Acid suppression with proton pump inhibitor on a long-term basis is the mainstay of treatment. Helicobacter pylori(H. pylori) is found in many sites including laryngeal mucosa and interarytenoid region. in this paper, we aim to present the relationship between LPR and H. pylori and review the current literature.

关键词： Laryngophrayngeal reflux Helicobacter pylori Gastroesophageal reflux disease Proton pump inhibitors

Square-root parametrization of dark energy in f(Q)cosmology

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2023年第12期75卷 105-114页

作者： m Koussour N myrzakulov Alnadhief H A Alfedeel E i Hassan d Sofuoğlu Safa m mirgani Quantum Physics and magnetism Team LPMCFaculty of Science Ben M'sikCasablanca Hassan II University L.N.Gumilyov Eurasian National University Ratbay myrzakulov Eurasian international Centre for Theoretical Physics department of mathematics and Statistics Imam Mohammad Ibn Saud Islamic University(IMSIU) department of Physics Faculty of ScienceUniversity of Khartoum Centre for Space Research North-West University department of Physics Istanbul University Vezneciler 34134

This paper is a parametrization of the equation of state(Eo S)parameter of dark energy(dE),which is parameterized using square-root(SR)form i.e.ω_(SR)=ω_(0)+ω_(1)z/√z^(2)+1,where ω_(0)and ω_(1) are free *** parametrization is examined in the context of the recently suggested f(Q)gravity theory as an alternative to general relativity(GR),in which gravitational effects are attributed to the non-metricity scalar Q with the functional form f(Q)=Q+αQ^(n),whereαand n are arbitrary *** derive observational constraints on model parameters using the Hubble dataset with 31 data points and the Supernovae(SNe)dataset from the Pantheon samples compilation dataset with 1048 data *** the current model,the evolution of the deceleration parameter,density parameter,EoS for dE,and Om(z)diagnostic have all been *** has been shown that the deceleration parameter favors the current accelerated expansion *** has also been shown that the EoS parameter for dE has a quintessence nature at this time.

关键词： cosmology dark energy f(Q)gravity EoS parameter

Study of TiO_2 thin films on Si substrate by the photoacoustic elastic bending method

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,mechanics & Astronomy) 2013年第7期56卷 1285-1293页

作者： TOdOROVi dragan m RABASOVi mihailo d mARKUSHEV dragan d FRANKO mladen TANGAR Urka Lavreni institute for multidisciplinary Research University of Belgrade institute of Physics University of Belgrade Laboratory for Environmental Research University of Nova Gorica

The quantitative photoacoustic investigation of different TiO2 thin films on Si substrates is presented using the elastic bending method. Photoacoustic signal amplitude and phase spectra versus modulation frequency were measured and analyzed using different sample thicknesses. Within the proposed method particular attention is given to the analysis of optical, thermal, elastic and structural sample parameters. Considerable focus is devoted to the fitting procedure of experimental results using the two-layer sample theoretical model. Characteristics of previously developed photoacoustic apparatus are discussed, attempting to search the ideal experimental conditions which can provide a good signal-to-noise ratio and sensitivity.

关键词： photoacoustic TiO2 thin films

Polyplex interaction strength as a driver of potency during cancer immunotherapy

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第10期11卷 5642-5656页

作者： Shannon d. Tsai James i. Andorko Xiangbin zeng Joshua m. Gammon Christopher m. dewell Fischell department of Bioengineering University of Marylond 8278 Paint Branch Drive College Park MD 20742 USA Robert E. Fischell institute for Biomedicol devices University of Maryland 8278 Paint Branch Drive College Park MD 20742 USA United States department of Veterans Affairs Maryland VA Health Care System 10 North Greene Street Baltimore MD 21201 USA deportment of microbiology and immunology University of Maryland Medical School 685 West Baltimore Street Baltimore MD 21201 USA marlene and Stewart Greenebaum Cancer Center 22 South Greene Street Baltimore MD 21201 USA

many experimental cancer vaccines are exploring toll-like receptor agonists （TLRas） such as CpG, a dNA motif that agonizes toll-like receptor 9 （TLR9）, to trigger immune responses that are potent and molecularly-specific. The ability to tune the immune response is especially important in the immunosuppressive microenvironments of tumors. Because TLR9 is located intracellularly, CpG must be internalized by immune cells for functionality. Polyplexes can be self- assembled through electrostatics using dNA （anionic） condensed by a positively charged carrier. These structures improve cell delivery and have been widely explored for gene therapy. in contrast, here we use cationic poly （^-amino esters）（PBAEs） to assemble polyplexes from CpG as an adjuvant to target and improve immune stimulation in cells and mouse models. Polyplexes were formed over a range of PBAE：CpG ratios, resulting in a library of complexes with increasingly positive charge and stronger binding as PBAE：CpG ratio increased. Although higher PBAE：CpG ratios exhibited improved CpG uptake, lower ratios of PBAE：CpG--which condensed CpG more weakly, activated dCs and tumorspecific T cells more effectively. in a mouse melanoma model, polyplexes with lower binding affinities improved survival more effectively compared with higher binding affinities. These data demonstrate that altering the polyplex interaction strength impacts accessibility of CpG to TLRs in immune cells. Thus, physiochemical properties, particularly the interplay between charge, uptake, and affinity, play a key role in determining the nature and efficacy of the immune response generated. This insight identifies new design considerations that must be balanced for engineering effective immunotherapies and vaccines.

关键词： cancer immunotherapy nanoparticle vaccine polyplex