聚合物流体在纳米颗粒和微生物存在下的流动和传热分析

本文采用FENE-P模型,研究纳米颗粒和微生物对聚合物通过水平伸缩薄片的流动和传热的影响以及对阻力系数、Nusselt数,Sherwood数和运动密度数的潜在影响。利用适当的相似性变换,将控制非牛顿聚合物流体流动的非线性偏微分方程组简化为恰当的相似形式。利用基于有限差分格式的MATLAB code bvp4c和修正的边界条件对修正的常微分方程组进行数值求解。以表格形式列出了工业中这些流动参数是如何影响流体物理性能的,并详细分析了相关物理参数对速度、温度、浓度和微生物分布的影响。结果表明,聚合物添加剂降低了阻力系数和Nusselt数。Sherwood数和运动密度数也受到聚合物添加剂的明显影响。

Landfill Sites Identification Using GIS and Multi-Criteria Method: A Case Study of Intermediate City of Punjab, Pakistan

Escalation in population over time triggered the abrupt exploitation of natural resources for human survival trough industrialization that ultimately caused splendid increase in the waste generation. This industrial development resulted in the migration of rural community toward urban areas. Management of urban waste is a great challenge for the urban administration. However, technologies have been developed to manage the waste in environmental friendly and sustainable manner. Sanitary landfill sites are one of the latest methods of disposing the municipal solid waste in an environment friendly and sustainable manner. Government and administrative authorities are adopting this technology for the management of urban solid waste. Present study is about identifying landfill sites for the Sahiwal city with an area of 1160 square kilometer and projected population of 1.57 million persons in 2016. Geographical Information System (GIS) is used for the identification of appropriate landfill site (LFS) that can fulfill the need of city in future and is selected based on the sustainable and eco-friendly criteria. The criteria are developed keeping in view the proximity from several land-use features i.e. water bodies, roads, settlements, agricultural land, bare land and existing disposal sites. The weights of the criteria are quantified using pair-wise comparison method in Analytic Hierarchy Process (AHP). The weights are incorporated in GIS spatial data environment and are assigned to proximity threshold of each criterion. Ultimately a map for each criterion is developed highlighting suitable, least suitable, less suitable and un-suitable areas with respect to each specific criterion. These maps are spatially overlaid which result in a final map that identifies most suitable landfill sites for solid waste disposal. The five identified sites are then prioritized based on their distances from the city center and area available. All identified sites are on the bare land and contain considerable buffer from environmentally sensitive receptors.

Influence of polymers on drag and heat transfer of nanofluid past stretching surface: A molecular approach

This article studies the influence of polymers on drag reduction and heat transfer enhancement of a nanofluid past a uniformly heated permeable vertically stretching surface. Our prime focus is on analyzing the possible effects of polymer inclusion in the nanofluid on drag coefficient, Nusselt number and Sherwood number. Dispersion model is considered to study the behavior of fluid flow and heat transfer in the presence of nanoparticles. Molecular approach is opted to explore polymer addition in the base fluid. An extra stress arises in the momentum equation as an outcome of polymer stretching. The governing boundary layer equations are solved numerically. Dependence of physical quantities of engineering interest on different flow parameters is studied. Reduction in drag coefficient, Nusselt number and Sherwood number is noticed because of polymer additives.

Three-dimensional MHD flow over a shrinking sheet: Analytical solution and stability analysis

The magnetohydrodynamic（MHD） steady and unsteady axisymmetric flows of a viscous fluid over a two-dimensional shrinking sheet are addressed. The mathematical analysis is carried out in the presence of a large magnetic field. The steady state problem results in a singular perturbation problem having an infinite domain singularity. The secular term appearing in the solution is removed and a two-term uniformly valid solution is derived using the Lindstedt–Poincaré technique. This asymptotic solution is validated by comparing it with the numerical solution. The solution for the unsteady problem is also presented analytically in the asymptotic limit of large magnetic field. The results of velocity profile and skin friction are shown graphically to explore the physical features of the flow field. The stability analysis of the unsteady flow is made to validate the asymptotic solution.

Metaplastic Carcinoma of the Breast: A Clinical Study of 7 Cases from Balochistan

Metaplastic carcinomas of the breast are rare heterogenous neoplasms characterized by adenocarcinoma with dominant areas of spindle cells, squamous and/or other mesenchymal differentiation, that comprise of <5% of all invasive breast cancers. Our objective in this study was to review the pathological features and clinical outcomes for metaplastic carcinoma of breast in breast cancer patients registered in CENAR (Center for Nuclear Medicines and Radiotherapy), Balochistan. Present study was performed on 7 patients affected with metaplastic carcinoma of breast, who were registered patients in CENAR. Informed consent was taken from the patients and BMI was calculated by measuring the height and weight of the patients. Available clinical history obtained by retrieving the patients file and a copy of biopsy report was also obtained from the file. Metaplastic carcinoma of breast was 4.11% of all 170 breast cancer cases registered in CENAR from 2010-2012. Mean age was 40 years ranging from 25 - 50 years. Four subtypes of metaplastic carcinoma of breast were reported in this study;DCIS component was present in one case and mean tumor size was 6.12 cm ranging from 3.5 - 10 cm. Metaplastic carcinomas of breast are rare heterogenous neoplasm with different characteristics, demographics and tumor biology and accounts for almost >5% of all breast cancer cases.