Evaluation of Bentonite Mixed Indigenous Clays for Development of Clay Liners

This study presents experimental investigation of indigenous clays mixed with Bentonite to assess their suitability in potential use as clay liners. Soil samples with 0, 4, 8, and 12% Bentonite content from three different sites in Peshawar region were tested for various geotechnical properties. Grain size distribution, specific gravity, Atterberg limits and free swell were found through laboratory tests using appropriate ASTM procedures. Maximum dry density and optimum moisture content were calculated using Atterberg limits in available relationships. Finally, one dimensional consolidation tests were conducted to find relevant parameters for calculating hydraulic conductivity. A decrease in specific gravity, increase in free swell, and in optimum moisture content, decline in maximum dry density and hydraulic conductivity was observed with increase in Bentonite content across all three soil samples. During free swell, the soil clusters become larger leading to formation of floccules resulting in the narrowing of inter-particle space and thus blocking of permeable paths. It is concluded that 8% Bentonite content by weight yields a suitable mixture for a clay liner that has hydraulic conductivity in the range of recommended limits

Wind-to-hydrogen production potential for selected sites in Pakistan

This paper provides a comprehensive assessment of wind energy potential for Hydrogen production under local conditions of Pakistan from the design, development and practical implementation perspectives. Simulations were performed for three sites - Bahawalpur, Sanghar and Gwadar using actual wind speed site data, recorded between 2016 and 2018, at intervals of 10 minute. For the selected sites, wind resource assessment was performed using the Weibull distribution function parameters, energy and wind-power density calculations at hub heights of 20m, 40m, 60m and 80m of the wind turbines. It was observed that Sanghar is the most suitable site for wind-to-Hydrogen production potential with power and energy density of 305.86W/m{2} and 2665.81kWh/m{2} , respectively. From the implementation perspective, the Nordex N90/2500 wind turbine at an 80m hub height was found to be beneficial for Sanghar with a cost of energy of 35.21/MWh (0.035/kWh). The cost of Hydrogen using an electrolyzer for 7-year long-term investment was 2.29 k/ton using Nordex N90/2500 turbine. Based on the available power density and land area, a general scheme for production of Hydrogen using electrolysis can be implemented with possibility of installation and commissioning of wind farms

Copy-Move Forgery Detection Technique for Forensic Analysis in Digital Images

Due to the powerful image editing tools images are open to several manipulations; therefore, their authenticity is becoming questionable especially when images have influential power, for example, in a court of law, news reports, and insurance claims. Image forensic techniques determine the integrity of images by applying various high-tech mechanisms developed in the literature. In this paper, the images are analyzed for a particular type of forgery where a region of an image is copied and pasted onto the same image to create a duplication or to conceal some existing objects. To detect the copy-move forgery attack, images are first divided into overlapping square blocks and DCT components are adopted as the block representations. Due to the high dimensional nature of the feature space, Gaussian RBF kernel PCA is applied to achieve the reduced dimensional feature vector representation that also improved the efficiency during the feature matching. Extensive experiments are performed to evaluate the proposed method in comparison to state of the art. The experimental results reveal that the proposed technique precisely determines the copy-move forgery even when the images are contaminated with blurring, noise, and compression and can effectively detect multiple copy-move forgeries. Hence, the proposed technique provides a computationally efficient and reliable way of copy-move forgery detection that increases the credibility of images in evidence centered applications

Content Based Image Retrieval Using Embedded Neural Networks with Bandletized Regions

One of the major requirements of content based image retrieval (CBIR) systems is to ensure meaningful image retrieval against query images. The performance of these systems is severely degraded by the inclusion of image content which does not contain the objects of interest in an image during the image representation phase. Segmentation of the images is considered as a solution but there is no technique that can guarantee the object extraction in a robust way. Another limitation of the segmentation is that most of the image segmentation techniques are slow and their results are not reliable. To overcome these problems, a bandelet transform based image representation technique is presented in this paper, which reliably returns the information about the major objects found in an image. For image retrieval purposes, artificial neural networks (ANN) are applied and the performance of the system and achievement is evaluated on three standard data sets used in the domain of CBIR

Assessing Institutional Preparedness of Pakistani Medical Schools towards Curriculum Change Using MORC

Purpose: Changing community needs and disease patterns are the major stimulator for change in medical curriculum throughout the world. The process of change depends on many factors that come under the umbrella of organizational readiness for its successful implementation. Inappropriate planning and low levels of organizational readiness for change will result in failure of change process. Methodology: A quantitative study design was chosen for this study. Medical school’s organizational readiness questionnaire (MORC) was used to collect data. The questionnaire consists of 53 items further categorized into three scales and twelve subscales. The questionnaire was distributed among faculty members of four medical colleges of Punjab, collected data was coded and descriptive and inferential statistics were applied for analysis using SPSS. Analysis revealed that all four medical colleges were having good organizational readiness to adopt change. Findings: The results of descriptive analysis showed, that majority of the respondents (47%) were agreed that their medical school, is in preparatory phase, 29%respondents showed that their institute is in more than two years of implementation phase of curriculum change, 23.8% agreed that in their medical school is in first two years of implementation phase. Implication: MORC is a reliable instrument for assessing institutional preparedness for curriculum change

Water–energy nexus for water distribution systems: a literature review

Water and energy are interdependent on each other. Energy is required to supply water to a system while, at the same time, water is needed for power generation in any natural or artificial system. This relationship is often called the water–energy nexus (WEN). In a water supply system, energy is consumed for source water extraction, transmission, treatment, and distribution. About 7%–8% of the world’s total generated energy is used for drinking water production and distribution. A major portion of this energy is used for distribution, i.e., pumping, chlorination, and maintenance activities, and hence is the focus of this review. Most of the world’s energy is generated by fossil fuels (oil, gas, and coal), which results in greenhouse gas (GHG) emissions. Here we review studies conducted to assess and evaluate the energy consumption and the related GHG emissions in water distribution systems (WDSs). This review covers the basic concepts and studies on WEN, energy saving solutions, renewable energy resources for water pumping, optimization of design, and the life cycle assessment (LCA) of large WDSs. Most of the reviewed studies suggest a trade-off between energy cost and the associated GHG emissions when selecting fixed-speed pumps over variable-speed pumps for large WDSs. To mitigate CO2 emissions, renewable energy resources like solar, wind, and mini-water turbines for water pumping have been discussed and mini-water turbines were found to be energy efficient solutions. The energy-focused LCA model has been studied to investigate the environmental impacts, GHG emissions, operational energy, and various life cycle stages of pipe manufacturing (embodied energy) in the network. Case studies of real world WDSs are reviewed and the potential research gaps are identified. Most life cycle studies have focused on the areas of pipe replacement, the life cycle cost of the system, the operational energy, and the reduction of GHG emissions, whereas less attention has been paid to the geographical and socio-economic issues along with the areas of human health, water resource diversity, and the hydraulic characteristics of WDSs.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Impact Resistance of Styrene–Butadiene Rubber (SBR) Latex-Modified Fiber-Reinforced Concrete: The Role of Aggregate Size

Improvements in tensile strength and impact resistance of concrete are among the most researched issues in the construction industry. The present study aims to improve the properties of concrete against impact loadings. For this purpose, energy-absorbing materials are used along with fibers that help in controlling the crack opening. A polymer-based energy-absorbing admixture, SBR latex, along with polypropylene fibers are used in this study to improve the impact resistance. Along with fibers and polymers, the effect of the size of aggregates was also investigated. In total, 12 mixes were prepared and tested against the drop weight test and the Charpy impact test. Other than this, mechanical characterization was also carried out for all the 12 concrete mixes. Three dosages of SBR latex, i.e., 0%, 4%, and 8% by weight of cement, were used along with three aggregates sizes, 19 mm down, 10 mm down, and 4.75 mm down. The quantity of polypropylene fibers was kept equal to 0.5% in all mixes. In addition to these, three control samples were also prepared for comparison. The mix design was performed to achieve a normal-strength concrete. For this purpose, a concrete mix of 1:1.5:3 was used with a water to a cement ratio of 0.4 to achieve a normal-strength concrete. The experimental study concluded that the addition of SBR latex improves the impact resistance of concrete. Furthermore, an increase in impact resistance was also observed for a larger aggregate size. The use of fibers and SBR latex is encouraged due to their positive results and the fact that they provide an economical solution for catering to impact strains. The study concludes that 4% SBR latex and 0.5% fibers with a larger aggregate size improve the resistance against impact loads