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Control strategies of avian influenza pandemic model with time delay

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International Journal of Biomathematics 2017年第7期10卷 219-236页

作者： u. Roman z. Gul I. Saeed u. Hakeem S. Shafie Department of Mathematics Bacha Khan University Charsadda Khyber Pakhtunkhwa Pakistan Department of Mathematics University of Malakand Chakdara Dir(Lower) Khyber Pakhtunkhwa Pakistan Department of Mathematics Abdul Wali Khan University Mardan Khyber Pakhtunkhwa Pakistan Department of Mathematical Sciences universiti Teknologi Johor Bahru Malaysia

A mathematical model for avian influenza with optimal control strategies is presented as a system of discrete time delay differential equations （DDEs） and its important math-ematical features are analyzed. In alignment to manage this, we develop an optimally controlled pandemic model of avian influenza and insert a time delay with exponential factor. Then we apply two controlled functions in the form of biosecurity of poultry and the education campaign against avian influenza to control the disperse of the dis- ease. Our optimal control strategies will minimize the number of contaminated humans and contaminated birds. We also derive the basic reproduction number to examine the dynamical behavior of the model and demonstrate the existence of the controlled system. For the justification of Our work, we present numerical simulations.

关键词： Time-delay optimal control existence numerical simulation

In vivo and in vitro study of resorbable magnesium wires for medical implants:Mg purity,surface quality,zn alloying and polymer coating

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Journal of Magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： K.Tesar J.Luňácková M.Jex M.Žaloudková R.Vrbová M.Bartoš P.Klein L.Vištejnová J.Dušková E.Filová z.Sucharda M.Steinerová S.Habr K.Balík A.Singh Department of Materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental Medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon Materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural Materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

Magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of Mg-based *** low-alloyed Mg-zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure Mg,commercially pure Mg,Mg-0.15zn,Mg-0.4zn and Mg-1zn was ***,Mg-0.4zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed Mg-induced osteogenesis,polymer-coated Mg wires with a small addition of zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： Magnesium Resorbable Mg wire Mg-zn implant degradation Biocompatibility study zn grain boundary segregation

LONGITuDINAL DISPERSION IN SEDIMENT-LADEN OPEN CHANNEL FLOWS

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International Journal of Sediment Research 2004年第01期19卷 1-14页

作者： z.AHMAD,u.C.KOTHYARI,K.G.RANGA RAJu Asst.Professor of Civil Engineering Indian Inst.of Tech. Roorkee(Formerly university of Roorkee) ROORKEE-247 667 INDIA Professor of Civil Engineering Indian Inst. of Tech. Roorkee ROORKEE-247 667 INDIA. Professor of Civil Engineering Indian Inst. of Tech. Roorkee ROORKEE-247 667 INDIA.

Laboratory experiments on longitudinal dispersion in clear-water and sediment-laden open channel flows are reported. Data from these experiments and those available from previous studies indicate that the suspended sediment present in the flow affects the longitudinal dispersion process. The observed velocity distributions over the depth of sediment-laden flows indicate that the velocity deviates from the mean velocity more in sediment-laden flows than in clear-water flows. The velocity distributions over the cross section and secondary flow in the channel are also expected to be altered due to the presence of suspended sediments in the flow. For these reasons, more dispersion is found in sediment-laden flows than in corresponding clear-water flows. A predictor for the dispersion coefficient in sediment-laden flows is proposed.

关键词： Longitudinal dispersion Open channel Sediment-laden flow Pollutants Velocity distribution

Titanium diboride-metals gradient materials prepared by field activated diffusion bonding process

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China Welding 2009年第4期18卷 10-14页

作者：陈少平张楠孟庆森 u．Cosan z．A．Munir Department of Material Science and Engineering Taiyuan University of TechnologyTaiyuan 030024. Department of Chemical Engineering and Materials Science University of California DavisCA 59616 USA.

Functionally gradient samples are prepared by getting metal Ni or Cu bonded with Ni-matrix composites reinforced by TiB2 particles by field activated diffusion bonding process. The intermetallic compound of Ni3Al has been applied as a mediate layer in order to reduce residual stress. The microstracture, phase composition of the interfaces between the metal and Ni3Al are determined and the mechanical properties of the gradient materials are characterized. Elemental concentration profiles across the interfaces between layers showed significant diffusion dissolution and formation of firm bonds. Measured micro-hardness values of the sample increased monotonically from the metal substrate to the surface layer of composites. The values for the surface composite layer ranged from about 2 000 HK to 3 300 HK. The results of this investigation demonstrate the feasibility of field activated diffusion bonding process for rapid preparation of FGMs.

关键词： electric field functionally gradient materials TiB2 Ni3Al diffusion bonding

Prevalence of plasmid mediated bla_(TEM-1) and bla_(CTX-M-15) type extended spectrum beta-lactamases in patients with sepsis

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Asian Pacific Journal of Tropical Medicine 2012年第2期5卷 98-102页

作者： Shahzad F Haque Saeedut-z Ali Mohammed TP Asad u Khan Department of Medicine J.N.Medical CollegeAligarhIndia Interdisciplinary Biotechnology unit AMUAligarh Muslim UniversityAligarhIndia Department of Medicine J.N.Medical College.AligarhIndia

Objective:To characterize the bacterial pathogens in patients having gram negative septicaemia. Further,to evaluate the antimicrobial resistance and underlying molecular mechanisms in these ***:A total number of 70 cases of gram negative sepsis were included in this prospective,open labeled,observational *** methods for isolation and identification of bacteria were *** susceptibility and ESBL testing was performed by the standard disc diffusion *** amplification was performed to identify blaub>CTX-Mub>,blaub>SHVub>and blaub>TEMub> type *** experiments were performed to show resistant marker transfer. Results:The most prevalent isolates Escherichia coli（***） 58.6%,Klebsiella Spp.32.9%and Pseudomonas 8.6%,were resistant to most of the antimicrobials including cefazolin,ceftriaxone, cefuroxime,ampicillin and co-trimoxazole but sensitive to imipenem and *** and MBL production was seen 7.3%and 12.2%of *** isolates *** isoaltes were found to have blaub>CTX-M-15ub> and two of them also showed blaub>TEM-1ub> type ***, none of them showed blaub>SHVub>.Conjugation experiments using J-53 cells confirmed these resistant markers as plasmid ***:This work highlights the molecular epidemiology of escalating antimicrobial resistance and likely switch over of blaub>CTX-M-15ub> type extended spectrum beta-lactamases by blaub>TEMub> type ESBLs in ***,the antimicrobial resistance by horizontal gene transfer was predominant among Enterobacteraceae in the community setting.

关键词： Gram negative sepsis ESBL Antimicrobial resistance

Annual and seasonal changes of the air temperature with altitude in the upper Dades valley, High Atlas, Morocco

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Journal of Mountain Science 2022年第1期19卷 85-102页

作者： ŻMuDzKA Elwira DŁuŻEWSKI Maciej DĄBSKI Maciej LEzIAK Kamil ROJAN Elżbieta Department of Climatology Faculty of Geography and Regional StudiesUniversity of WarsawKrakowskie Przedmieście 3000-927 WarsawPoland Department of Geomorphology Faculty of Geography and Regional StudiesUniversity of WarsawKrakowskie Przedmieście 3000-927 WarsawPoland

The purpose of this study is to determine the size of air temperature changes with altitude in the mountains of the arid zone, on the example of the upper Dades valley(High Atlas, Morocco). The air temperature change with altitude was determined on the basis of 5 years data from three meteorological stations. The analysis was carried out on an annual and seasonal basis. The annual and daily variations of thermal gradients between pairs of stations were also determined. It was found that the average thermal gradient in the upper Dades valley was-1.02℃ per 100 m. The highest values of the thermal gradient occur in winter and the lowest in summer. In winter,the thermal gradient was characterized by the greatest variability. Minima of the daily variation of air temperature gradients were observed in early morning hours and maxima around midday. In the lower part of the valley, air temperature inversion frequently developed between 10 AM and 3 PM *** obtained results show high thermal gradients in the mountains of the arid zone, with their annual amplitude increasing in the lower parts of the *** instantaneous values of the gradients were significantly modified by the supply of latent heat and the occurrence of dust storms. It has been shown that the advection factor plays an important role in shaping large gradient values. The study contains novel results of thermal gradient measurements in high mountains of arid zone.

关键词： Air temperature gradient Thermal inversion Annual and seasonal variability Synoptic situation High mountains of arid zone High Atlas Mountains

Wavelet analysis of stagnation point flow of non-Newtonian nanofluid

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Applied Mathematics and Mechanics(English Edition) 2019年第8期40卷 1211-1226页

作者： M.HAMID M.uSMAN R.u.HAQ4 z.H.KHAN Wei WANG School of Mathematical Sciences Peking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Department of Electrical Engineering Bahria UniversityIslamabad 44000Pakistan State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource & HydropowerSichuan UniversityChengdu 610065China Key Laboratory of Advanced Reactor Engineering and Safety Ministry of Education Tsinghua UniversityBeijing 100084China

The wavelet approach is introduced to study the influence of the natural convection stagnation point flow of the Williamson fluid in the presence of thermophysical and Brownian motion effects. The thermal radiation effects are considered along a permeable stretching surface. The nonlinear problem is simulated numerically by using a novel algorithm based upon the Chebyshev wavelets. It is noticed that the velocity of the Williamson fluid increases for assisting flow cases while decreases for opposing flow cases when the unsteadiness and suction parameters increase, and the magnetic effect on the velocity increases for opposing flow cases while decreases for assisting flow cases. When the thermal radiation parameter, the Dufour number, and Williamson’s fluid parameter increase, the temperature increases for both assisting and opposing flow cases. Meanwhile, the temperature decreases when the Prandtl number increases. The concentration decreases when the Soret parameter increases, while increases when the Schmidt number increases. It is perceived that the assisting force decreases more than the opposing force. The findings endorse the credibility of the proposed algorithm, and could be extended to other nonlinear problems with complex nature.

关键词： Williamson nanofluid heat and mass transfer stagnation point flow assisting and opposing flow Chebyshev wavelet method

Dynamics of bioconvection flow of micropolar nanoparticles with Cattaneo-Christov expressions

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Applied Mathematics and Mechanics(English Edition) 2020年第9期41卷 1333-1344页

作者： S.A.SHEHzAD T.MuSHTAQ z.ABBAS A.RAuF S.u.KHAN I.TLILI Department of Mathematics COMSATS University IslamabadSahiwal 57000Pakistan Department of Mathematics COMSATS University IslamabadVehari 61100Pakistan Department of Mathematics The Islamia University of BahawalpurBahawalpur 63100Pakistan Institute of Research and Development Duy Tan UniversityDa Nang 550000Vietnam Faculty of Civil Engineering Duy Tan UniversityDa Nang 550000Vietnam

A numerical analysis is performed to analyze the bioconvective double diffusive micropolar non-Newtonian nanofluid flow caused by stationary porous *** consequences of the current flow problem are further extended by incorporating the Brownian and thermophoresis *** energy and mass species equations are developed by utilizing the Cattaneo and Christov model of heat-mass *** flow equations are converted into an ordinary differential model by employing the appropriate *** numerical solution is reported by using the MATLAB builtin bvp4c *** consequences of engineering parameters on the flow velocity,the concentration,the microorganisms,and the temperature profiles are evaluated *** numerical data for fascinating physical quantities,namely,the motile density number,the local Sherwood number,and the local Nusselt number,are calculated and executed against various parametric *** microrotation magnitude reduces for increasing magnetic *** intensity of the applied magnetic field may be utilized to reduce the angular rotation which occurs in the lubrication processes,especially in the suspension of *** the account of industrial applications,the constituted output can be useful to enhance the energy transport efficacy and microbial fuel cells.

关键词： bioconvection flow micropolar fluid nanoparticle Cattaneo-Christov theory porous disk

Dual solutions in MHD stagnation-point flow of Prandtl fluid impinging on shrinking sheet

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Applied Mathematics and Mechanics(English Edition) 2014年第7期35卷 813-820页

作者： N.S.AKBAR z.H.KHAN R.u.HAQ S.NADEEM Department of Basic Science & Humanities College of Electrical & Mechanical Engineering(CEME) National University of Sciences and Technology Islamabad 46000 Pakistan School of Mathematical Sciences Peking University Department of Mathematics University of Malakand Khyber Pakhtunktwo 18800 Pakistan Department of Mathematics Quaid-i-Azam University Islamabad 44000 Pakistan

The present article investigates the dual nature of the solution of the magneto- hydrodynamic （MHD） stagnation-point flow of a Prandtl fluid model towards a shrinking surface. The self-similar nonlinear ordinary differential equations are solved numerically by the shooting： method. It is found that the dual solutions of the flow exist for cer- tain values of tile velocity ratio parameter. The special case of the first branch solutions （the classical Newtonian fluid model） is compared with the present numerical results of stretching flow. The results are found to be in good agreement. It is also shown that the boundary layer thickness for the second solution is thicker than that for the first solution.

关键词： stagnation-point flow shrinking sheet Prandtl fluid magnetohydrody-namic (MHD) dual solution shooting method