A novel fractional case study of nonlinear dynamics via analytical approach

The present work describes the fractional view analysis of Newell-Whitehead-Segal equations,using an innovative technique.The work is carried with the help of the Caputo operator of fractional derivative.The analytical solutions of some numerical examples are presented to confirm the reliability of the proposed method.The derived results are very consistent with the actual solutions to the problems.A graphical representation has been done for the solution of the problems at various fractional-order derivatives.Moreover,the solution in series form has the desired rate of convergence and provides the closed-form solutions.It is noted that the procedure can be modified in other directions for fractional order problems.

Spin-orbit torque effect in silicon-based sputtered Mn_(3)Sn film

Noncollinear antiferromagnet Mn_(3)Sn has shown remarkable efficiency in charge-spin conversion,a novel magnetic spin Hall effect,and a stable topological antiferromagnetic state,which has resulted in great interest from researchers in the field of spin-orbit torque.Current research has primarily focused on the spin-orbit torque effect of epitaxially grown noncollinear antiferromagnet Mn_(3)Sn films.However,this method is not suitable for large-scale industrial preparation.In this study,amorphous Mn_(3)Sn films and Mn_(3)Sn/Py heterostructures were prepared using magnetron sputtering on silicon substrates.The spin-torque ferromagnetic resonance measurement demonstrated that only the conventional spin-orbit torque effect generated by in-plane polarized spin currents existed in the Mn_(3)Sn/Py heterostructure,with a spin-orbit torque efficiency of 0.016.Additionally,we prepared the perpendicular magnetized Mn_(3)Sn/CoTb heterostructure based on amorphous Mn_(3)Sn film,where the spin-orbit torque driven perpendicular magnetization switching was achieved with a lower critical switching current density(3.9×10^(7)A/cm^(2))compared to Ta/CoTb heterostructure.This research reveals the spin-orbit torque effect of amorphous Mn_(3)Sn films and establishes a foundation for further advancement in the practical application of Mn_(3)Sn materials in spintronic devices.

曲壁面两相流的简单扩散界面浸没边界法

针对在欧拉-拉格朗日网格框架下曲边界上的两相流润湿边界条件实施问题,本文提出了一种简单扩散界面浸没边界法。在此方法的框架下,静止和移动曲边界的湿润边界条件都可以采用平板边界方式处理。在该方法中,我们在实际边界内外一个拉格朗日网格间距处添加了两层虚拟贴体拉格朗日网格,并通过插值得到三层拉格朗日点上的序参数,从而得到实际的曲边界润湿条件。该方案实施思路简单,不仅适用于静止曲边界,还适用于复杂的运动曲边界。为了验证该方法的有效性,本文在广义守恒相场格子玻尔兹曼方法(LBM)框架下,模拟了静态液滴在圆柱上的铺展、动态液滴撞击圆柱、圆柱在水池中沉降三个问题。结果表明该方法能够有效地模拟曲面上的两相流动,具有良好的精度、鲁棒性和质量守恒性。

浸没边界–简化热格子Boltzmann方法研究及其应用

针对流固耦合传热问题,本文提出了一种基于浸没边界–简化热格子玻尔兹曼方法 (immersed boundary method–simplified thermal lattice Boltzmann method,IB-STLBM)的耦合模型.不同于传统的格子玻尔兹曼方法使用分布函数演化流场和温度场,简化热格子玻尔兹曼方法 (simplified thermal lattice Boltzmann method,STLBM)的演化过程不需要依赖分布函数,只涉及平衡态分布函数和非平衡态分布函数,能够直接演化宏观量,极大减小了计算过程中所占用的虚拟内存,简化了边界条件的实现方式,同时具有较高的稳定性.传统的浸没边界法对流场的计算采用欧拉网格,对固体边界采用拉格朗日网格,认为固体边界是对流场产生某种体积力.在应用浸没边界法时,汲取介观的思想,把固体的介入看作是对流场的干扰,打破了固体附近流体介观微团颗粒原始的平衡状态,这种干扰可以看作是在耦合边界上产生的一个非平衡项,可用非平衡态分布函数来表示.基于此,在模型中浸没边界法与简化热格子玻尔兹曼方法更紧密联系在一起,更大程度发挥二者的优点,整个计算过程更加简单直观,符合物理特性.通过对热圆柱绕流和内含热颗粒的封闭方腔自然对流问题的模拟以及对其结果的分析,验证了该算法在求解流固耦合传热问题的有效性和可行性.

A numerical study for WENO scheme-based on different lattice Boltzmann flux solver for compressible flows

In this paper,the finite difference weighted essentially non-oscillatory (WENO) scheme is incorporated into the recently developed four kinds of lattice Boltzmann flux solver (LBFS) to simulate compressible flows,including inviscid LBFS Ⅰ,viscous LBFS Ⅱ,hybrid LBFS Ⅲ and hybrid LBFS Ⅳ.Hybrid LBFS can automatically realize the switch between inviscid LBFS Ⅰ and viscous LBFS Ⅱ through introducing a switch function.The resultant hybrid WENO-LBFS scheme absorbs the advantages of WENO scheme and hybrid LBFS.We investigate the performance of WENO scheme based on four kinds of LBFS systematically.Numerical results indicate that the devopled hybrid WENO-LBFS scheme has high accuracy,high resolution and no oscillations.It can not only accurately calculate smooth solutions,but also can effectively capture contact discontinuities and strong shock waves.

Antibiotic resistance and cagA gene correlation:A looming crisis of Helicobacter pylori

AIM:To determine antibiotic resistance of Helicobacter pylori(H.pylori) in Pakistan and its correlation with host and pathogen associated factors.METHODS:A total of 178 strains of H.pylori were isolated from gastric biopsies of dyspeptic patients.Susceptibility patterns against first and second-line antibiotics were determined and trends of resistance were analyzed in relation to the sampling period,gastric conditions and cagA gene carriage.The effect of cagA gene on the acquisition of resistance was investigated by mutant selection assay.RESULTS:The observations showed that monoresistant strains were prevalent with rates of 89% for metronidazole,36% for clarithromycin,37% for amoxicillin,18.5% for ofloxacin and 12% for tetracycline.Furthermore,clarithromycin resistance was on the rise from 2005 to 2008(32% vs 38%,P = 0.004) and it is significantly observed in non ulcerative dyspeptic patients compared to gastritis,gastric ulcer and duodenal ulcer cases(53% vs 20%,18% and 19%,P = 0.000).On the contrary,metronidazole and ofloxacin resistance were more common in gastritis and gastric ulcer cases.Distribution analysis and frequencies of resistant mutants in vitro correlated with the absence of cagA gene with metronidazole and ofloxacin resistance.CONCLUSION:The study confirms the alarming levels of antibiotic resistance associated with the degree of gastric inflammation and cagA gene carriage in H.pylori strains.

Engineered Hybrid Materials with Smart Surfaces for Effective Mitigation of Petroleum-Originated Pollutants

The generation and controlled or uncontrolled release of hydrocarbon-contaminated industrial wastewater effluents to water matrices are a major environmental concern.The contaminated water comes to surface in the form of stable emulsions,which sometimes require different techniques to mitigate or separate effectively.Both the crude emulsions and hydrocarbon-contaminated wastewater effluents contain suspended solids,oil/grease,organic matter,toxic elements,salts,and recalcitrant chemicals.Suitable treatment of crude oil emulsions has been one of the most important challenges due to the complex nature and the substantial amount of generated waste.Moreover,the recovery of oil from waste will help meet the increasing demand for oil and its derivatives.In this context,functional nanostructured materials with smart surfaces and switchable wettability properties have gained increasing attention because of their excellent performance in the separation of oil–water emulsions.Recent improvements in the design,composition,morphology,and fine-tuning of polymeric nanostructured materials have resulted in enhanced demulsification functionalities.Herein,we reviewed the environmental impacts of crude oil emulsions and hydrocarbon-contaminated wastewater effluents.Their effective treatments by smart polymeric nanostructured materials with wettability properties have been stated with suitable examples.The fundamental mechanisms underpinning the efficient separation of oil–water emulsions are discussed with suitable examples along with the future perspectives of smart materials.

The Effects of a Backward Bifurcation on a Continuous Time Markov Chain Model for the Transmission Dynamics of Single Strain Dengue Virus

Global incidence of dengue, a vector-borne tropical disease, has seen a dramatic increase with several major outbreaks in the past few decades. We formulate and analyze a stochastic epidemic model for the transmission dynamics of a single strain of dengue virus. The stochastic model is constructed using a continuous time Markov chain (CTMC) and is based on an existing deterministic model that suggests the existence of a backward bifurcation for some values of the model parameters. The dynamics of the stochastic model are explored through numerical simulations in this region of bistability. The mean of each random variable is numerically estimated and these are compared to the dynamics of the deterministic model. It is observed that the stochastic model also predicts the co-existence of a locally asymptotically stable disease-free equilibrium along with a locally stable endemic equilibrium. This co-existence of equilibria is important from a public health perspective because it implies that dengue can persist in populations even if the value of the basic reproduction number is less than unity.

Acoustic Emission Characterization of Matrix Damage Initiation in Woven CFRP Composites

In this paper, an experimental investigation is performed using acoustic emission (AE) technique to study the behaviour of crack initiation and propagation of woven carbon fibre reinforced plastic (CFRP) composites under static tensile loading. Three laminates with three plies each were manufactured and tested under tensile static loading. Damage was being monitored using AE technique with instantaneous AE hits energies being used as the damage parameter. Results showed that angle ply laminates experienced crack initiations at about 50% of ultimate tensile strength whereas cross ply laminates and non-conventional angle ply laminates having one cross ply laminate experienced initiation of cracks at about a third of ultimate tensile strength. This early cracks initiation is believed to be caused by the presence of 90° plies that cannot take much load transversely.

Evaluation of heat stress effects on cellular and transcriptional adaptation of bovine granulosa cells

Background:Heat stress is known to affect follicular dynamics,oocyte maturation,and fertilization by impairing steroidogenic ability and viability of bovine granulosa cell(bGCs).The present study explored the physiological and molecular response of bGCs to different heat stress intensities in-vitro.We exposed the primary bGCs to heat stress(HS)at 39℃,40℃ and 41℃ along with control samples(38℃)for 2 h.To evaluate the impact of heat stress on bGCs,several in vitro cellular parameters including cell apoptosis,intracellular reactive oxygen species(ROS)accumulation and HSP70 kinetics were assessed by flow cytometry,florescence microscopy and western blot,respectively.Furthermore,the ELISA was performed to confirm the 17β-estradiol(E2)and progesterone(P4)levels.In addition,the RNA sequencing(RNA-Seq)method was used to get the molecular based response of bGCs to different heat treatments.Results:Our findings revealed that the HS significantly decreased the cell viability,E2 and P4 levels in bGCs,whereas,increased the cellular apoptosis and ROS.Moreover,the RNA-Seq experiments showed that all the treatments(39℃,40℃ and 41℃)significantly regulated many differentially expressed genes(DEGs)i.e.BCL2L1,STAR,CYP11A1,CASP3,SOD2,HSPA13,and MAPK8IP1 and pathways associated with heat stress,apoptosis,steroidogenesis,and oxidative stress.Conclusively,our data demonstrated that the impact of 40°C treatment was comparatively detrimental for cell viability,apoptosis and ROS accumulation.Notably,a similar trend of gene expression was reported by RT-qPCR for RNA-seq data.Conclusions:Our study presented a worthy strategy for the first time to characterize the cellular and transcriptomic adaptation of bGCs to heat stress(39,40 and 41°C)in-vitro.The results infer that these genes and pathways reported in present study could be useful candidates/indicators for heat stress research in dairy cattle.Moreover,the established model of bGCs to heat stress in the current study provides an appropriate platform to understand the mechanism of how heat-stressed bGCs can affect the quality of oocytes and developing embryo.

Role of Chemohormonal Therapy in Management of Patients with Metastatic Hormone Sensitive Prostate Cancer

Androgen deprivation therapy has been the mainstay of treatment for management of metastatic hormone sensitive prostate cancer. Recently conducted randomized controlled trials with docetaxel based chemotherapy have shed light on benefit of early use chemotherapy for hormone sensitive prostate cancer. In this review, we aim to comprehensively describe recent trials which are changing the paradigm in support of up front use of docetaxel based chemotherapy for metastatic hormone sensitive prostate cancer.

Financial Variables and Systematic Risk

The objective of this study is to examine the relationship among financial determinants and systematic risk of cement industry. Five financial variables are utilized as components, i.e. industry size, operating efficiency, liquidity, profitability, and financial leverage in this study. Six years data from 2008 to 2013 have been collected from Karachi Stock Exchange. The consequences of 29 cement industries showed that there is a huge relationship between industry size, operating efficiency, and profitability with 181 systematic risk and results similar to past studies while liquidity and financial leverage have not a significant relationship with beta （systematic risk）. Results are profitable for budgetary approach creators and investors to expand the profits.

Implementation of Research for Quality of Care Project! Measuring and Improving Physician Compliance with WHO Clinical Practice Guidelines for ＇Iron Deficiency Anemia in Children＇

Iron deficiency anemia （IDA） is the most prevalent anemia globally. As per WHO, 600 million children worldwide have IDA. Additionally, National Nutrition Survey 2011, Pakistan revealed 61.9% children are anaemic. In our project we measure and improve physicians compliance with WHO Clinical practice guidelines for ＇Iron deficiency anemia in children＇. Juran＇s Problem Solving Methodology was applied. Pre-survey results suggest 81.1% children are anemic. Only 11.4% and 10.6% are on regular Iron supplementation and deworming agents respectively. Though （93.4%） physicians surveyed have comprehensive knowledge. Moreover, merely 13.7% parents have some knowledge about IDA. We choose Ishikawa Fish Bone Diagram for cause and effect analysis and ＇Gant Chart＇ to allocate timelines. We implement certain strategies like Physician＇s questionnaire form, refresher courses, information material for parents, and sustain supply of medicines. Post survey analysis concluded significant increased prescription rate of Iron supplementation and deworming agents as well as parents knowledge for IDA. For long-term sustainability, we established Policy, Quality indicators, Posters/Brochures and regular refresher courses. We also ensure adequate and sustain supply of iron supplementations and deworming agents at subsidized rates in hospital pharmacy. In responses to our project, we found under-practice of WHO recommendations despite comprehensive physician＇s knowledge.

Assessment of Bholari River Sand for Its Geotechnical Characterization as Fine Aggregate

Present study is aimed at assessment of Bholari river sand for its geo­technical characterization and suitability as fine aggregate which is being quarried in Jamshoro district,Sindh,Pakistan.For this purpose,sand samples(n=11)were collected from quarry sites and main river channel.Physical properties reveal that Bholari sand is mainly coarse to fine in size(0.2 mm-5 mm).Average values of fineness modulus,specific gravity,bulk density and void content of collected samples are 2.58,2.56,1659.90 kg/m^(3) and 35.12%respectively which varied within the corresponding permissible ranges of ACI(American Concrete Institute).Carbonate content of about 57.59%is also in agreement with corresponding range for fine aggregate.Petrographic examination revealed that Bholari River sand mainly compris­es of quartz and rock fragments with subordinate limestone fragments.As per classification of Dott(1964),Bholari sand is lithic arenite where quartz(50%)occurs as main mineral followed by rock fragments(30%),feldspars(15%)and other opaque minerals(5%).Texturally,the sediments are angu­lar(77%)to sub-round(33%).All these physical properties lie within the range set by National Highway Authority(NHA)and American Standard of Testing Material(ASTM).It is concluded that Bholari River sand is suita­ble for use in concrete mixed with cement and asphalt.

Assessment of Geotechnical Properties of Laki Limestone for Coarse Aggregate, Nooriabad, Jamshoro Sindh, Pakistan

Present study is aimed at assessment of geotechnical properties of Laki limestone as coarse aggregate which is being quarried in Nooriabad area,Sindh,Pakistan.Coarse aggregate samples(n=20)of limestone were collected for the evaluation of physico-mechanical properties of the aggregate.Petrographic analysis revealed that the aggregate comprises of hard,compact,massive,crystalline and fossiliferous limestone.It is devoid of any reactive silica(chert,chalcedony)and other harmful constituents like clays or organic matter.Average values of specific gravity,absorption,bulk density,void content and combined index(EI+FI)of collected samples are 2.5,2.1%,1.54 g/cc,38.55%and 13.04%respectively.The values of specific gravity(2.3-2.9),absorption(0-8%),bulk density(1.28 g/cc-1.92 g/cc)and void content(30%-45%)are varying within the range of normal weight aggregate as per American concrete institute(ACI)specifications.On the other hand,absorption values of aggregate samples are slightly higher(2.1%)than the reference range(2%)but meet other requirements.Mechanical properties including aggregate impact value(8.58%),aggregate crushing value(26.66%),Loss Angeles abrasion value(24.77%),sodium sulfate soundness(4.72%),water soluble sulfate(0.006%)and water soluble chloride(0.005%)are found to be within corresponding guidelines set by ASTM.On the other hand,average carbonate content is found to be 89.64%indicating that Laki limestone is of slightly low purity.Except absorption,all physical and mechanical properties lie within specified ranges.It is concluded that Laki limestone is suitable for use as road aggregate and concrete mix design.

Estimating the basic reproductive ratio for the Ebola outbreak in Liberia and Sierra Leone

Background:Ebola virus disease has reemerged as a major public health crisis in Africa,with isolated cases also observed globally,during the current outbreak.Methods:To estimate the basic reproductive ratio R0,which is a measure of the severity of the outbreak,we developed a SEIR(susceptible-exposed-infected-recovered)type deterministic model,and used data from the Centers for Disease Control and Prevention(CDC),for the Ebola outbreak in Liberia and Sierra Leone.Two different data sets are available:one with raw reported data and one with corrected data(as the CDC suspects under-reporting).Results:Using a deterministic ordinary differential equation transmission model for Ebola epidemic,the basic reproductive ratio R0 for Liberia resulted to be 1.757 and 1.9 for corrected and uncorrected case data,respectively.For Sierra Leone,R0 resulted to be 1.492 and 1.362 for corrected and uncorrected case data,respectively.In each of the two cases we considered,the estimate for the basic reproductive ratio was initially greater than unity leading to an epidemic outbreak.Conclusion:We obtained robust estimates for the value of R0 associated with the 2014 Ebola outbreak,and showed that there is close agreement between our estimates of R0.Analysis of our model also showed that effective isolation is required,with the contact rate in isolation less than one quarter of that for the infected non-isolated population,and that the fraction of high-risk individuals must be brought to less than 10%of the overall susceptible population,in order to bring the value of R0 to less than 1,and hence control the outbreak.

Estimating the basic reproduction number for single-strain dengue fever epidemics

Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pakistan in order to assess the transmissibility of the disease.We obtain estimates of the basic reproduction number R0 from epidemic data using different methodologies applied to different epidemic models in order to evaluate the robustness of our estimate.Results:We first estimate model parameters by fitting a deterministic ODE vector-host model for the transmission dynamics of single-strain dengue to the epidemic data,using both a basic ordinary least squares(OLS)as well as a generalized least squares(GLS)scheme.Moreover,we perform the same analysis for a direct-transmission ODE model,thereby allowing us to compare our results across different models.In addition,we formulate a direct-transmission stochastic model for the transmission dynamics of dengue and obtain parameter estimates for the stochastic model using Markov chain Monte Carlo(MCMC)methods.In each of the cases we have considered,the estimate for the basic reproduction number R0 is initially greater than unity leading to an epidemic outbreak.However,control measures implemented several weeks after the initial outbreak successfully reduce R0 to less than unity,thus resulting in disease elimination.Furthermore,it is observed that there is strong agreement in our estimates for the pre-control value of R0,both across different methodologies as well across different models.However,there are also significant differences between our estimates for the post-control value of the basic reproduction number across the two different models.Conclusion:In conclusion,we have obtained robust estimates for the value of the basic reproduction number R0 associated with the 2011 dengue fever epidemic before the implementation of public health control measures.Furthermore,we have shown that there is close agreement between our estimates for the post-control value of R0 across the different methodologies.Nevertheless,there are also significant differences between the estimates for the post-control value of R0 across the two different models.

Optimal control analysis of Ebola disease with control strategies of quarantine and vaccination

Background:The 2014 Ebola epidemic is the largest in history,affecting multiple countries in West Africa.Some isolated cases were also observed in other regions of the world.Method:In this paper,we introduce a deterministic SEIR type model with additional hospitalization,quarantine and vaccination components in order to understand the disease dynamics.Optimal control strategies,both in the case of hospitalization(with and without quarantine)and vaccination are used to predict the possible future outcome in terms of resource utilization for disease control and the effectiveness of vaccination on sick populations.Further,with the help of uncertainty and sensitivity analysis we also have identified the most sensitive parameters which effectively contribute to change the disease dynamics.We have performed mathematical analysis with numerical simulations and optimal control strategies on Ebola virus models.Results:We used dynamical system tools with numerical simulations and optimal control strategies on our Ebola virus models.The original model,which allowed transmission of Ebola virus via human contact,was extended to include imperfect vaccination and quarantine.After the qualitative analysis of all three forms of Ebola model,numerical techniques,using MATLAB as a platform,were formulated and analyzed in detail.Our simulation results support the claims made in the qualitative section.Conclusion:Our model incorporates an important component of individuals with high risk level with exposure to disease,such as front line health care workers,family members of EVD patients and Individuals involved in burial of deceased EVD patients,rather than the general population in the affected areas.Our analysis suggests that in order for R0(i.e.,the basic reproduction number)to be less than one,which is the basic requirement for the disease elimination,the transmission rate of isolated individuals should be less than one-fourth of that for non-isolated ones.Our analysis also predicts,we need high levels of medication and hospitalization at the beginning of an epidemic.Further,optimal control analysis of the model suggests the control strategies that may be adopted by public health authorities in order to reduce the impact of epidemics like Ebola.

Modeling transmission dynamics of Ebola virus disease

Ebola virus disease （EVD） has emerged as a rapidly spreading potentially fatal disease. Several studies have been performed recently to investigate the dynamics of EVD. In this paper, we study the transmission dynamics of EVD by formulating an SEIR-type transmission model that includes isolated individuals as well as dead individuals that are not yet buried. Dynamical systems analysis of the model is performed, and it is consequently shown that the disease-free steady state is globally asymptotically stable when the basic reproduction number, R0 is less than unity. It is also shown that there exists a unique endemic equilibrium when R0 〉 1. Using optimal control theory, we propose control strategies, which will help to eliminate the Ebola disease. We use data fitting on models, with and without isolation, to estimate the basic reproductive numbers for the 2014 outbreak of EVD in Liberia and Sierra Leone.

Modelling ocular ageing in adults with well-controlled type I diabetes

Purpose:To develop a paraxial eye model based on a previously collected cohort of adults with well-controlled type 1 diabetes mellitus(DM1)and a limited range of refractive errors.Methods:The study used the previously published biometric data of 72 participants(Age:41.5
12.4 years)with DM1.Measurements included objective refraction,anterior and posterior corneal radii of curvatures,and internal distances.Moreover,phakometry was used to determine the lens radii of curvature and lens equivalent indices,from which the lens powers were calculated.A multivariate linear regression was performed for each biometric parameter with respect to current age(Age),the time since the onset of diabetes(Tdb),and current levels of glycated hemoglobin(HbA1c).The vitreous chamber depth was determined from other distances,and lens equivalent index was chosen to balance the models.These were compared with an existing model for nondiabetic eyes.Results:Some dependent parameters were not affected by the independent variables(spherical equivalent,anterior corneal radius of curvature,central corneal thickness),some were affected by time since onset(the lens radii of curvatures,anterior chamber depth)and others were affected by both age and time since onset(posterior corneal radius of curvature,lens thickness,axial length).None of the dependent parameters were affected by current levels of HbA1c.Conclusions:The proposed model accurately describes the age-related changes in the eyes of people with DM1.In this description the age of diabetes onset plays an important role,especially if the diabetes onset occurred during childhood.