Ghulam Ishaq Khan Institute of Engineering Sciences and Technology

About: Ghulam Ishaq Khan Institute of Engineering Sciences and Technology is a education organization based out in Topi, Pakistan. It is known for research contribution in the topics: Thin film & Quantum efficiency. The organization has 618 authors who have published 940 publications receiving 10674 citations.

How to tackle plastic bags and bottles pollution crisis in Pakistan? A cost–benefit analysis approach

Abstract: Plastic pollution is among the many socio-economic and environmental dilemmas that have engulfed Pakistan. The exponentially increasing consumption of plastic and the difficulty of dealing with its waste has compelled the government to impose a ban on the use of non-biodegradable plastics. This ban has made Pakistan the 128th country to curb plastic usage through punitive measures. However, the country lacks cheap and sustainable alternatives for plastic bags and bottles, which form the most significant chunk of plastic waste. This research study aims to analyze and propose alternatives that can replace these plastic bags and bottles without compromising the lifestyle of citizens. The aim of this study is two-fold; first, it employs Fuzzy VIKOR, a Multi-Criteria Decision-Making technique for comparison and prioritization of alternatives, i.e., Conventional Plastic bags, Paper bags, and Bioplastic bags, with respect to multiple aspects of sustainability. Secondly, it performs a cost–benefit analysis of a Bioplastic plant, with a focus on the production of biodegradable plastic bottles. The MCDM analysis prioritized the bioplastic bags, followed by paper bags and the least preferable alternative turned out to be conventional plastic bags. The cost–benefit analysis indicated that although the production of bioplastic bottles instead of conventional plastic bottles would lead to the reduction of detrimental environmental impacts, however, currently it is not financially profitable for the industrialists to switch to bioplastics. Therefore, it is recommended that government authorities should incorporate carbon taxes and subsidize the sustainable development sector, which would, in turn, lead to the reduction of plastic consumption and waste in society.

Analysis of Interference Mitigation in Heterogeneous Cellular Networks using Soft Frequency Reuse and Load Balancing

Abstract: One of the promising solutions to meet the demands for ubiquitous coverage and high capacity in heterogeneous cellular networks (HCNets) is the co-deployment of small base stations (sBSs) inside the coverage region of a macro base station BS. Due to its high transmit power, most of the users get associated with BS. This results in imbalanced load distribution across the HCNets. To balance the load, users from BS are offloaded to low power sBSs to decrease the BS load and increase network capacity. However, BS now acts as a strong interferer for offloaded users. Therefore, a proactive interference mitigation technique together with load balancing is required to mitigate the interference and balance the network load. In this paper, we use the soft frequency reuse (SFR) scheme to abate such interference. Furthermore, we use cell range expansion (CRE) based cell association where coverage regions of sBSs are increased by using cell association bias to include more users. Moreover, we derive coverage probability expressions for the proposed model. Numerical results demonstrate that the SFR scheme together with association bias reduce interference and balance network load distribution.

Module Level Electronic Circuit Based PV Array for Identification and Reconfiguration of Bypass Modules

Abstract: In this article, a novel electronic circuit based on optocoupler is designed for each module of photovoltaic (PV) array to deal with partial shading conditions. The proposed circuit not only provides electronic monitoring at the module level but also ensures the reconfiguration of bypass modules. The control framework of the proposed scheme works in two steps. In Step-1 , the PV array is connected in series-parallel (SP) configuration and the power-voltage (P-V) curve is traced to search the global maximum (GM). In Step-2 , bypass modules are separated from PV array through their respective electronic circuits in a decentralized control manner, and the power of bypass modules is stored in the battery. The proposed electronic circuit provides a low cost solution as it is free from expensive sensing and complex switching network. Moreover, the control operation of proposed scheme is simple. The proposed scheme is verified through computer-aided simulations and a hardware prototype of 170 W. The comparative study indicates that the proposed scheme yields more energy than past proposed solutions.

Frequency Dependent Electrical Characteristics οf Au/n-Si/CuPc/Au Heterojunction

Abstract: Electrical characteristics of the heterojunction fabricated by thermal deposition of copper phthalocyanine (CuPc) on an n-silicon substrate have been investigated. The frequency has significant effect on capacitance (C), conductance (G) and series resistance (Rs) interface states (Dit) of the junction. Measured capacitance and conductance were corrected for Rs. The conductance technique was used to measure the density of the interface states. This method revealed the value of the interface state density distribution for the Au/n-Si/CuPc/Au interfaces of the order of 10 cm−2 eV−1.