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Techno-economic design of a grid-tied Photovoltaic system for a residential building
Asad A. Naqvi,Talha Bin Nadeem,Ahsan Ahmed,Muhammad Uzair,S. Asad Ali Zaidi Techno-Press 2022 Advances in energy research Vol.8 No.1
Increasing cost of electricity due to rising price of fuel is one of the local community's main issues. In this research, switching of grid dependent system to the grid-tied Photovoltaic (PV) system with net metering for a residential building is proposed. The system is designed by considering the maximum energy demand of the building. The designed system is analyzed using RETScreen on technical, economic and environmental grounds. It is found that the system is able to produce 12,000 kWh/year. The system is capable to fulfill the electricity demand of the building during day time and is also capable to sell the energy to the local grid causing the electric meter to run in reverse direction. During night time, electricity will be purchased from grid, and electric meter will run in the forward direction. The system is economically justified with a payback period of only 3 years with net present value of PKR. 4,758,132. Also, the system is able to reduce 7.2 tons of CO<sub>2</sub> not produced in the entire life of the project.
Effects of Different Lightweight Functional Fillers for Use in Cementitious Composites
Asad Hanif,Zeyu Lu,Yu Cheng,Su Diao,Zongjin Li 한국콘크리트학회 2017 International Journal of Concrete Structures and M Vol.11 No.1
The effects of different lightweight functional fillers on the properties of cement-based composites are investigated in this study. The fillers include fly ash cenospheres (FACs) and glass micro-spheres (GMS15 and GMS38) in various proportions. The developed composites were tested for compressive, flexural and tensile strengths at 10 and 28-day ages. The results indicated that both FACs and GMS38 are excellent candidates for producing strong lightweight composites. However, incorporation of GMS15 resulted in much lower specific strength values (only up to 13.64 kPa/kg m3) due to its thinner shell thickness and lower isostatic crushing strength value (2.07 MPa). Microstructural analyses further revealed that GMS38 and GMS15 were better suited for thermal insulating applications. However, higher weight fraction of the fillers in composites leads to increased porosity which might be detrimental to their strength development.
Performance analysis tool for reinforced concrete members
Asad Esmaeily,Robert J. Peterman 한국계산역학회 2007 Computers and Concrete, An International Journal Vol.4 No.5
A computer program was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load. This performance is significantly affected by the loading history. Different monotonic material models as well as hysteresis rules for confined and unconfined concrete and steel, some developed and calibrated against test results on material samples, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis. One of the assumptions on curvature distribution along the member was based on a method developed to address the variation of the plastic hinge length as a result of loading pattern. Functionality of the program was verified by reproduction of analytical results obtained by others for several cases, and accuracy of the analytical process and the implemented models were evaluated against the experimental results from large-scale reinforced concrete columns tested under the analyzed loading cases. While the program can be used to predict the response of a member under a certain loading pattern, it can also be used to examine various analytical models and methods or refine a custom material model against test data.
COVID-19 and pancreatitis: A review of the potential association
Asad Ali Kerawala,Bhagwan Das,Rabika Fatima,Ahda Solangi 소화기인터벤션의학회 2023 International journal of gastrointestinal interven Vol.12 No.1
Originally thought to be a respiratory pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), has been shown to cause a dizzying array of symptoms, including all major organ systems of the human body. As time elapsed, new strains of the virus have emerged, validating concerns about genetic mutation. No single treatment has proven beneficial in treating the consequences, and the world has been left at the mercy of this deadly pathogen. It has been proven that COVID-19 can cause strokes, myocardial infarcts, mesenteric infarcts, acute limb ischemia, and a wide array of other symptomatology. This review aimed to evaluate whether there exists an association between COVID-19 and pancreatitis. Forty publications (34 case reports and 4 case series) were included in the review. In total, 44 cases of acute pancreatitis (38 cases of acute edematous pancreatitis and 6 cases of necrotizing pancreatitis) in COVID-19 patients without any predisposing factors have been published since January 2020. Fortunately, only 4 (9.1%) of these patients were reported to have died. Although the exact mechanism by which COVID-19 causes pancreatitis is still unclear, studies so far have reported it as a multifactorial phenomenon. COVID-19 associated pancreatic injury is thought to involve direct cellular damage via local replication of SARS-CoV-2 within pancreatic cells, as they express angiotensin-converting enzyme 2 receptors even more strongly than lung cells. Our review concludes that acute pancreatitis should be kept in the differential list of all COVID-19 patients with gastrointestinal manifestations, especially in patients with acute abdomen.
Seismic retrofit of a framed structure using damped cable systems
Asad Naeem,김진구 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.3
The purpose of this study is to investigate the effectiveness of damped cable systems (DCS) to mitigate the earthquake-induced responses of a building frame structure. The seismic performance of the DCS is investigated using the fragility analysis and life cycle cost evaluation of an existing building retrofitted with the DCS, and the results are compared with the structure retrofitted with conventional fluid viscous dampers. The comparison of the analysis results reveals that, due to the self-centering capability of the DCS, residual displacement approximately reaches to zero for the structure retrofitted with the DCS. The fragility analysis shows that the structure retrofitted with the DCS has the least probability of reaching the specific limit states compared to the bare structure and the structure with the conventional fluid viscous damper (VD), especially under the severe ground motions. It is also observed that both the initial and the life cycle costs of the DCS seismic retrofitting technique is lesser compare to the structure retrofitted with the VD.
Context-Aware Handover Skipping for Train Passengers in Next Generation Wireless Networks
Asad, Syed,Klaine, Paulo,Rais, Rao Naveed Bin,Mollel, Michael,Hussain, Sajjad,Abbasi, Qammer,Imran, Muhammad 한국통신학회 2023 Journal of communications and networks Vol.25 No.3
5G spectral efficiency requirements foresee net-work densification as a potential solution to improve capac-ity and throughput to target next-generation wireless net-works (NGWNs). This is achieved by shrinking the footprint ofbase stations (BSs), effective frequency reuse, and dynamic useof shared resources between users. However, such a deploymentresults in unnecessary handovers (HOs) due to the cell sizedecrements, and limited sojourn time on a high train mobility. In particular, when a train speedily passes through the BS radiocoverage footprints, frequent HO rate may result in seriouscommunication interruption impacting quality of service (QoS). This paper proposes a novel context-aware HO skipping thatrelies on passenger mobility, trains trajectory, travelling timeand frequency, network load and signal to interference and noiseratio (SINR) data. We have modelled passenger traffic flows incardinal directions i.e, north, east, west, and south (NEWS),in a novel framework that employs realistic Poisson pointprocess (PPP) for real-time mobility patterns to support mo-bile networks. Spatio-temporal simulations leveraging NEWSmobility prediction model with machine learning (ML) wheresupport vector machine (SVM) shows an accuracy of 94.51%. ML-driven mobility prediction results integrate into our proposedscheme that shows comparable coverage probability, and averagethroughput to the no skipping case, while significantly reducingHO costs.
Adaptive Control of a Shape Memory Alloy Actuator using Neural-Network Feedforward and RISE Feedback
Asad Ullah Awan,박재만,김현진,류정현,조맹효 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.4
This paper presents a position tracking control system for a shape memory alloy (SMA) actuator using neural network (NN) feedforward and robust integral of signum of error (RISE) feedback. Nonlinear control of SMA actuators is difficult due to model uncertainties and unknown disturbances. Discontinuous control techniques such as sliding mode control have conventionally been used to achieve asymptotic tracking in the presence of model uncertainties. However, such discontinuous controllers usually result in increased power loss due to high frequency switching. With the recent development of the continuous RISE feedback control, semiglobal asymptotic tracking can be achieved. Furthermore, the NN-RISE control leads to better tracking performance and lower power losses caused by input signal switching/chattering when compared to discontinuous controllers. In order to apply the NN-RISE, a state-space model of the SMA actuator is derived, which has been overlooked in many previous works, using Taylor series expansion and exploiting the nature of SMA dynamics. Experimental results show that the proposed control system works well even in the absence of an accurate model of the SMA actuator.