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  • 1
    Publication Date: 2019
    Description: In the present work we consider a numerical solution for laminar, incompressible, and steady oblique stagnation point flow of Cu − water nanofluid over a stretching/shrinking sheet with mass suction S . We make use of the Cattaneo–Christov heat flux model to develop the equation of energy and investigate the qualities of surface heat transfer. The governing flow and energy equations are modified into the ordinary differential equations by similarity method for reasonable change. The subsequent ordinary differential equations are illuminated numerically through the function bvp4c in MATLAB. The impact of different flow parameters for example thermal relaxation parameter, suction parameter, stretching/shrinking parameter, free stream parameter, and nanoparticles volume fraction on the skin friction coefficient, local Nusselt number, and streamlines are contemplated and exposed through graphs. It turns out that the lower branch solution for the skin friction coefficient becomes singular in shrinking area, although the upper branch solution is smooth in both stretching and shrinking domain. For oblique stagnation-point flow the streamlines pattern are not symmetric, and reversed phenomenon are detected close to the shrinking surface. Also, we observed that the free stream parameter changes the direction of the oncoming flow and controls the obliqueness of the flow. The existing work mostly includes heat and mass transfer as a mechanism for improving the heat transfer rate, which is the main objective of the authors.
    Electronic ISSN: 2073-8994
    Topics: Mathematics
    Published by MDPI
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  • 2
    Publication Date: 2019
    Description: The livelihood of the people in the Himalayan range of Pakistan is largely dependent on the cultivation of fruits. Apricot and apple are the major fruits of this region, which are marketed throughout the country and also exported to other countries. Due to high perishability and the poor farm-to-market infrastructure in the region, farmers are unable to get maximum returns. This study was conducted keeping in view the importance of the region and the impacts of fruits on the livelihood of the farmhands. Cross-sectional data from 200 respondents were collected through a multistage random sampling technique. Factor analysis was employed to find out the constraint in the apricot production and propensity score matching estimates were employed to see the impact of apricot production on the farming communities in the study area. The results of the factor analysis show the most important group of constraints in the growth of the apricot industry is awareness, which is an internal factor. This is followed by production, policy, and marketing constraints. The least important is processing technology. Furthermore, the results show that apricot production has a significant positive impact on decreasing the poverty level of the household, depicting a great potential for the development of resilient livelihoods.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 3
    Publication Date: 2018
    Description: Entrepreneurship is often considered a male-gendered concept, and carries masculine connotations. However, the importance of women entrepreneurs and their contribution to the economy has recently been realized. Nonetheless, there is limited research about female entrepreneurship and social entrepreneurship in the developing countries context. This paper challenges the implicit masculinism of the traditional entrepreneurship research, and aims to explore the enablers and constraints of female social entrepreneurship within the context of a developing country. Our theoretical focus is based on institutional and feminist perspectives, thus developing logic through reconciling predictions from these two competing theories. This integration contributes by offering novel insights about social entrepreneurship. Utilising an interpretive qualitative research approach, data from in-depth interviews with ten female social entrepreneurs of KP, Pakistan were analyzed using thematic analysis. Empirically, we identify and discuss a number of interesting and explanatory themes affecting female entrepreneurship such as “women empowerment, patriarchal culture, role of culture and societal norms, religious extremism and terrorism, forced entrepreneurs, change creators, unique institutional constraints, institutional corruption and security issues”. The findings highlight female entrepreneurs’ struggle for sustainability, and explain how this occurs. The paper also provides an interesting insight into how context determines social entrepreneurship in KP, Pakistan.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 4
    Publication Date: 2019
    Description: The winter season in Nanjing is from December to February, with extremely low temperature and high humidity due to seasonal snowfall. During these extreme cold climatic conditions, plants have to survive severe heat stress conditions, even if they are being kept in greenhouses. The objective of this study was to investigate a heating system that can provide heat directly to the root zone instead of heating the entire greenhouse, which is a viable option to reduce energy consumption. Root zone heating could be an effective alternative for the sustainable development of plants during the winter. A novel type of root zone heating system was applied to evaluate the energy consumption during different greenhouse ambient temperature conditions, the effects of root zone heating systems on pepper plant morphology, and heat transfer rates to plant canopy in the greenhouse. The temperature treatments in root zone heating system were T-15, T-20, T-25, T-30, and a control treatment (TC) at 15 °C, 20 °C, 25 °C, and 30 °C, respectively, while TC received no heat. A simulation study was carried out to validate the root zone temperature. The results of the current investigation revealed that energy consumption has an inverse relationship to the ambient temperature of the greenhouse, while temperature gradients to the plant canopy observed from the lower to the upper part of the plant and the upper canopy experienced less temperature fluctuation as compared to the lower part of the plant. The results also showed that treatment T-20 had the maximum in terms of the leaf dry weight, stem diameter, and the number of leaves, while T-25 showed the maximum root dry weight and stem dry weight; T-30 and T-15 had minimum dry weights of plant segments among all treatments. Control treatment (TC) showed a minimum dry mass of plant. The root zone heating with optimal root zone temperature was found to be a viable and adaptable option as this leads to improved energy consumption patterns for the sustainable growth and development of plants in greenhouses during extremely low temperatures.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 5
    Publication Date: 2019
    Description: The aim of this investigation was to assess the corrosion behavior of gray cast iron (GCI) alloyed with copper. Alloyed GCI specimens were austempered isothermally at varying temperatures. After austenitizing at 927 °C, the samples were austempered at different temperatures ranging from 260 to 385 °C with an interval of 25 °C for 60 minutes. As a result, these samples developed an ausferrite matrix with different percentages of austenite. The resulting microstructures were evaluated and characterized by optical microscope (OM), scanning electron microscope (SEM), and X-ray diffraction (XRD). The corrosion characteristics were determined using potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) of these samples. These tests were carried out in a medium of 0.5 M H2SO4 and 3.5% NaCl solution. It was observed from the potentiodynamic polarization results that with increasing austempering temperature, the corrosion rate decreased. All results of the EIS were in accordance with a constant phase element (CPE) model. It was found that with an increase in austempering temperature, the polarization resistance (Rp) increased. The austenite content was also found to influence the corrosion behavior of the austempered gray cast iron (AGCI).
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by MDPI
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  • 6
    Publication Date: 2019
    Description: A chronic disease diabetes mellitus is assuming pestilence proportion worldwide. Therefore prevalence is important in all aspects. Researchers have introduced various methods, but still, the improvement is a need for classification techniques. This paper considers data mining approach and principal component analysis (PCA) techniques, on a single platform to approaches on the polytomous variable-based classification of diabetes mellitus and some selected chronic diseases. The PCA result shows eigenvalues, and the total variance is explained for the principal components (PCs) solution. Total of twelve attributes was analyzed with the intention to precise the pattern of the correlation with minimum factors as possible. Usually, factors with large eigenvalues retained. The first five components have their eigenvalues large enough to be retained. Their variances are 18.9%, 14.0%, 13.6%, 10.3%, and 8.6%, respectively. That explains ~65.3% of the total variance. We further applied K-means clustering with the aid of the first two PCs. As well, correlation results between diabetes mellitus and selected diseases; it has revealed that diabetes patients are more likely to have kidney and hypertension. Therefore, the study validates the proposed polytomous method for classification techniques. Such a study is important in better assessment on low socio-economic status zone regions around the globe.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by MDPI
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  • 7
    Publication Date: 2019
    Description: Proper straw cover information is one of the most important inputs for agroecosystem and environmental modeling, but the availability of accurate information remains limited. However, several remote-sensing (RS)-based studies have provided a residue cover estimation and provided spatial distribution mapping of paddy rice areas in a constant field condition. Despite this, the performance of rice crops with straw applications has received little attention. Furthermore, there are no methods currently available to quantify the wheat straw cover (WSC) percentage and its effect on rice crops in the rice-wheat cropping region on a large scale and a continuous basis. The novel approach proposed in this study demonstrates that the Landsat satellite data and seven RS-based indices, e.g., (i) normalized difference vegetation index (NDVI), (ii) Normalized difference senescent vegetation index (NDSVI), (iii) Normalized difference index 5 (NDI5), (iv) Normalized difference index 7 (NDI7), (v) Simple tillage index (STI), (vi) Normalized difference tillage index (NDTI), and (vii) Shortwave red normalized difference index (SRNDI), can be used to estimate the WSC percentage and determine the performance of rice crops over the study area in Changshu county, China. The regression model shows that the NDTI index performed better in differentiating the WSC at sampling points with a coefficient of determination (R2 = 0.80) and root mean squared difference (RMSD = 8.46%) compared to that of other indices, whereas the overall accuracy for mapping WSC was observed to be 84.61% and the kappa coefficient was κ = 0.76. Moreover, the rice yield model was established by correlating between the peak NDVI values and rice grain yield collected from ground census data, with R2 = 0.85. The finding also revealed that the highest estimated yield (8439.67 kg/ha) was recorded with 68% WCS in the study region. This study confirmed that the NDVI and NDTI algorithms are very effective and robust indicators. Also, it can be strongly concluded that multispectral Landsat satellite imagery is capable of measuring the WSC percentage and successively determines the impact of different WSC percentages on rice crop yield within fields or across large regions through remote sensing (RS) and geographical information system (GIS) techniques for the long-term planning of agriculture sustainability in rice-wheat cropping systems.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 8
    Publication Date: 2019
    Description: The grouping of clusters is an important task to perform for the initial stage of clinical implication and diagnosis of a disease. The researchers performed evaluation work on instance distributions and cluster groups for epidemic classification, based on manual data extracted from various repositories, in order to evaluate Euclidean points. This study was carried out on Weka (3.9.2) using 281 real-life health records of diabetes mellitus patients including males and females of ages〉20 and 〈87, who were simultaneously suffering from other chronic disease symptoms, in Nigeria from 2017 to 2018. Updated plugins of K-mean and self-organizing map(SOM) machine learning algorithms were used to cluster the data class of mellitus type for initial clinical implications. The results of the K-mean assessment were built in 0.21 seconds with nine iterations for “type” and eight for “class” attributes. Out of 281 instances, 87 (30.97%) were classified as negative and 194 (69.03%) as positive in the testing on the Euclidean space plot. By assessment for Euclidean points, SOM discovered the search space in a more effective way, but K-mean positioning potencies are impulsive in convergence. This study is important for epidemiological disease diagnosis in countries with a high epidemic risk and low socioeconomic status.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by MDPI
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  • 9
    Publication Date: 2019
    Description: Polycrystalline ceramics, such as alumina (Al2O3), are brittle and they generally wear by fracture mechanism, which limits their potential in tribological applications. In the present work, computational design tools are used to develop hybrid Al2O3 composites reinforced with best combinations of toughening and self-lubricating second-phase particles for cutting tool inserts in dry machining applications. A mean-field homogenization approach and J-integral based fracture toughness models are employed to predict the effective structural properties (such as elastic modulus and fracture toughness) and related to the intrinsic attributes of second- phase inclusions in Al2O3 matrix. Silicon carbide (SiC), boron nitride (cBN and hBN), zirconia (ZrO2), graphite, titanium dioxide (TiO2), and titanium carbide (TiC) were found the most suitable candidates to be added in Al2O3 matrix as individual or hybrid combinations. A series of samples including standalone Al2O3, single inclusion composites (Al2O3/SiC, Al2O3/cBN) and hybrid composites (Al2O3/SiC/cBN, Al2O3/SiC/TiO2 and Al2O3/SiC/graphite) are sintered by Spark Plasma Sintering (SPS) for validation purpose. Properties of the sintered composites are measured and compared with the proposed computational material design. Composition and phase transformation of the sintered samples are studied using X-ray diffraction (XRD) and Raman spectroscopy, while their morphology is studied using Field Emission Scanning Electron Microscope (FESEM). The presented nontraditional material design approach is found to significantly reduce experimental time and cost of materials in developing toughened and anti-friction ceramic composites.
    Electronic ISSN: 1996-1944
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by MDPI
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  • 10
    Publication Date: 2019
    Description: The thermodynamics of a Carreau nanoliquid thin film embedded with graphene nanoparticles past a stretching sheet is studied in the presence of inclined magnetic field and non-uniform heat source/sink. Graphene is a new two-dimensional amphiphilic macromolecule which has great applications due to its electrical and mechanical properties. The basic constitutive equations of Carreau nanoliquid for velocity and temperature have been used. Similarity transformations are adopted to achieve the nonlinear coupled differential equations accompanying boundary conditions embedded with different parameters. HAM (Homotopy Analysis Method) is used to solve the transformed equations for expressions of velocity and temperature. Graphs are shown which illustrate the effects of various parameters of interest. There exists a nice agreement between the present and published results. The results are useful for the thermal conductivity and in the analysis and design of coating processes.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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