Cogent Physics最新文献_第3页

Perturbation approximation for higher modes in nearly regular two-dimensional cavities 近规则二维腔中高模态的微扰近似

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1262725

N. Korneev

引用次数: 2

Some novel exponential function structures to the Cahn–Allen equation Cahn-Allen方程的一些新的指数函数结构

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1240886

H. Bulut, S. S. Atas, H. Baskonus

引用次数: 29

High gain, directive and miniaturized metamaterial C-band antenna 高增益、定向、小型化的超材料c波段天线

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1236510

P. Dawar, N. S. Raghava, A. De

引用次数: 4

Finite element modeling of radon distribution in natural soils of different geophysical regions 不同地球物理区域自然土壤氡分布的有限元模拟

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1254859

Y. Hafez, E. Awad

{"title":"Finite element modeling of radon distribution in natural soils of different geophysical regions","authors":"Y. Hafez, E. Awad","doi":"10.1080/23311940.2016.1254859","DOIUrl":"https://doi.org/10.1080/23311940.2016.1254859","url":null,"abstract":"Abstract Radon migration from deep soil to the earth’s surface is investigated numerically using a developed Finite Element numerical model. The objectives of this study are: to predict the radon profile variation with the soil depth, the radon diffusion coefficients in multi-layer soils, the surface radon concentrations, and the soil–air radon fluxes. The flexibility of the Finite Element Method allows for accommodating varying diffusion coefficients in multi-layer soils and expressing convective-type boundary conditions. The convective-type boundary condition assumes that the surface radon flux is proportional to the difference between the radon concentration in the ambient air and the radon concentration at the soil surface. Radon concentration profiles with depth were collected from several geophysical locations such as Greece, Germany, South Africa, and Jordan. The numerical results show that the multi-layer profile of radon in natural soils is more descriptive than the one-layer one used traditionally, where each layer has its own diffusion coefficient. The effective diffusion coefficient, D, shows variation with the soil depth and its value differs from one geophysical location to another. A constant soil–air interface transfer coefficient is calculated and the soil–air radon flux is accordingly estimated. In addition, the surface radon concentrations at the soil–air interface are calculated from the model and compared against extrapolated field data.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1254859","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60084721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Effect of drug Piper nigrum on magnesium chloride at varying concentration and temperature through ultrasonic method: A thermoacoustic study 超声热声法研究不同浓度和温度下药物黑椒对氯化镁的影响

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1262572

P. B. Nalle, S. S. Deshmukh, R. Dorik, K. M. Jadhav

{"title":"Effect of drug Piper nigrum on magnesium chloride at varying concentration and temperature through ultrasonic method: A thermoacoustic study","authors":"P. B. Nalle, S. S. Deshmukh, R. Dorik, K. M. Jadhav","doi":"10.1080/23311940.2016.1262572","DOIUrl":"https://doi.org/10.1080/23311940.2016.1262572","url":null,"abstract":"Abstract The ultrasonic velocity (U), density (ρ), and viscosity (η) of an ethanolic extract of drug Piper nigrum with MgCl2 (metal ions) have been measured as a function of the number of moles n = (0.7009, 1.4018, 2.1027, 2.8036 and 3.5045) at 303.15, 308.15, 313.15 and 318.15 K temperature. Various thermoacoustic and their excess values such as adiabatic compressibilities (β), intermolecular free lengths (Lf), excess adiabatic compressibility (βE), excess intermolecular free length () have been computed using values of ultrasonic velocity (U), density (ρ), and viscosity (η). The excess values of ultrasonic velocity, specific acoustic impedance are positive, whereas isentropic compressibility and intermolecular free lengths are negative over the entire composition range of MgCl2 + P. nigrum which indicates the presence of specific interactions between unlike molecules. Molecular association is reflected by ultrasonic investigation. This may be interpreted due to the of complex formation. The chemical interaction may involve the association due to the solute–solvent and ion–solvent interaction and due to the formation of charge-transfer complexes, which is useful to understand the mechanism of their metabolism in living systems. The results obtained from these studies are helpful for pharmacological applications of drugs, transport of drugs across biological membranes.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1262572","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60084757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optical characteristics of sol-gel derived M3SiO5:Eu3+ (M = Sr, Ca and Mg) nanophosphors for display device technology 溶胶-凝胶衍生M3SiO5:Eu3+ (M = Sr, Ca和Mg)纳米荧光粉的光学特性

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1262573

Devender Singh, Suman Sheoran, Shri Bhagwan, Sonika Kadyan

{"title":"Optical characteristics of sol-gel derived M3SiO5:Eu3+ (M = Sr, Ca and Mg) nanophosphors for display device technology","authors":"Devender Singh, Suman Sheoran, Shri Bhagwan, Sonika Kadyan","doi":"10.1080/23311940.2016.1262573","DOIUrl":"https://doi.org/10.1080/23311940.2016.1262573","url":null,"abstract":"Abstract A series of trivalent europium-doped M3SiO5 (M = Sr, Ca and Mg) phosphors were synthesized using sol–gel process at 950°C. Samples were further reheated at high temperature to study the effect of reheating on crystal structure and optical characteristics. X-ray diffraction measurement of these materials was carried out to know the crystal structure. Diffraction pattern showed monoclinic structure having space group Cm for Ca3SiO5 materials. However, tetragonal phase with space group P4/ncc was observed for Sr3SiO5 materials. Mg3SiO5 material show mixed diffraction peaks at 950 and 1,150°C. Transmission electron microscopic analysis was used to estimate the particle size of silicates. Photoluminescence emission spectra were recorded to check the luminescence properties of prepared materials. These phosphors exhibited a strong orange-red light under excitation at 395 nm. The prepared phosphors exhibited most intense peak in 610–620 nm region due to the 5D0→7F2 transition of europium (III) ion available in lattice. To overcome the deficiency of red silicates, M3SiO5 materials were explored and they might be integrated with ultraviolet LEDs to generate light which may be suitable for display applications.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1262573","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60084768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Ab-initio study on structural, elastic, electronic and optical properties of iron-based superconductor 铁基超导体结构、弹性、电子和光学性质的从头算研究

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1265779

U. Chowdhury, M. A. Rahman, M. A. Rahman, M. Bhuiyan

引用次数: 2

The Gaia era has started 盖亚时代已经开始

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1249542

K. Vieira

引用次数: 0

Parametric study of waste chicken fat catalytic chemical vapour deposition for controlled synthesis of vertically aligned carbon nanotubes 鸡废脂肪催化化学气相沉积控制合成垂直排列碳纳米管的参数研究

Cogent Physics Pub Date : 2016-12-31 DOI: 10.1080/23311940.2016.1247486

A. Suriani, A. Dalila, A. Mohamed, M. S. Rosmi, M. Mamat, M. F. Malek, M. Ahmad, N. Hashim, I. Isa, T. Soga, M. Tanemura

{"title":"Parametric study of waste chicken fat catalytic chemical vapour deposition for controlled synthesis of vertically aligned carbon nanotubes","authors":"A. Suriani, A. Dalila, A. Mohamed, M. S. Rosmi, M. Mamat, M. F. Malek, M. Ahmad, N. Hashim, I. Isa, T. Soga, M. Tanemura","doi":"10.1080/23311940.2016.1247486","DOIUrl":"https://doi.org/10.1080/23311940.2016.1247486","url":null,"abstract":"Abstract High-quality vertically aligned carbon nanotubes (VACNTs) were synthesised using ferrocene-chicken oil mixture utilising a thermal chemical vapour deposition (TCVD) method. Reaction parameters including vaporisation temperature, catalyst concentration and synthesis time were examined for the first time to investigate their influence on the growth of VACNTs. Analysis via field emission scanning electron microscopy and micro-Raman spectroscopy revealed that the growth rate, diameter and crystallinity of VACNTs depend on the varied synthesis parameters. Vaporisation temperature of 570°C, catalyst concentration of 5.33 wt% and synthesis time of 60 min were considered as optimum parameters for the production of VACNTs from waste chicken fat. These parameters are able to produce VACNTs with small diameters in the range of 15–30 nm and good quality (ID/IG ~ 0.39 and purity ~76%) which were comparable to those synthesised using conventional carbon precursor. The low turn on and threshold fields of VACNTs synthesised using optimum parameters indicated that the VACNTs synthesised using waste chicken fat are good candidate for field electron emitter. The result of this study therefore can be used to optimise the growth and production of VACNTs from waste chicken fat in a large scale for field emission application.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1247486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60084705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Synthesis and characterization of high-quality cobalt vanadate crystals and their applications in lithium-ion batteries 高品质钒酸钴晶体的合成、表征及其在锂离子电池中的应用

Cogent Physics Pub Date : 2016-12-23 DOI: 10.1080/23311940.2016.1265778

Md. Tofajjol Hossen Bhuiyan, M. A. Rahman, Md Atikur Rahman, R. Sultana, M. R. Mostafa., Asmaul Husna Tania, M. R. Sarker

引用次数: 7