Impact Of Distributed Generation On Power System Protection

This dissertation describes a simulation study of the impact of distributed generation (DG) interconnection to an existing distribution system of an Iraq system. The increase load demand in many countries pushes the electrical company to use DG technology to meet their load. From the literature review, it was found in spite of many positive effects of DG such as reduce the power losses and reduce voltage drop; the parallel operation of DG with an existing distribution system has many technical problems. One of the most significant issues of parallel operation is the change of fault level and suitability of existing protection system that indeed needs to be maintained within acceptable limits as defined in the international standards. Therefore, this dissertation is performed to investigate the impact of DG based synchronous generator driven by diesel engine on both the fault level and protection system. A small part of the distribution system in Baghdad capital-Iraq which the DG is currently interconnected at 11kV bus has been chosen and modeled using DIgSILENT PowerFactory version 15. The impacts of DG installation at three different locations, i.e. two possible locations which are 33kV and 132kV buses as well as the actual location have been investigated. The dissertation basically includes two investigations which are; examine the change in the fault level without the presence of DG and with DG interconnection at three interconnection locations by executing three-phase fault at each bus of the network as well as investigate the suitability of protection devices through performing single-line-to-ground and three-phase faults at 33kV and 11kV feeders within the distribution system. The results show that after an extensive simulation study, the increase in short circuit level is noticeable at the buses where the DG is interconnected and the protection performance of unidirectional overcurrent relay suffer from blinding and sympathetic tripping as well as the under reach of distance relay, therefore, a series remedy is needed for safety purposes and to reliability of the system

Developing magnetic functionalized multi-walled carbon nanotubes-based buckypaper for the removal of Furazolid

Magnetic f-MWCNTs-based BP/PVA membrane was fabricated and utilized for the elimination of furazolidone (FZD) from aqueous solution. Characterisation and adsorption studies were performed to evaluate the performance and adsorptive efficiency, respectively of the membrane. Furthermore, statistical and machine learning technique were also applied to predict the removal efficiency of FZD on the membrane. The results revealed that magnetic f-MWCNTs-based BP/PVA membrane has the potential to be used as an efficient membrane for practical applications

Optimization of depth-based routing for underwater wireless sensor networks through intelligent assignment of initial energy

Underwater Wireless Sensor Networks (UWSNs) are extensively used to explore the diverse marine environment. Energy efficiency is one of the main concerns regarding performance of UWSNs. In a cooperative wireless sensor network, nodes with no energy are known as coverage holes. These coverage holes are created due to non-uniform energy utilization by the sensor nodes in the network. These coverage holes degrade the performance and reduce the lifetime of UWSNs. In this paper, we present an Intelligent Depth Based Routing (IDBR) scheme which addresses this issue and contributes towards maximization of network lifetime. In our proposed scheme, we allocate initial energy to the sensor nodes according to their usage requirements. This idea is helpful to balance energy consumption amongst the nodes and keep the network functional for a longer time as evidenced by the results provided

Comparison of the Morbidity after Laparoscopic Cholecystectomy for Acutely Inflamed Gall Bladder with and without Drain Insertion: A Randomized Controlled Trial

Abstract Objective: The study objective is to compare the pain frequency and mean hospital stay in patients with and without drain insertion, following laparoscopic cholecystectomy for acutely inflamed gallbladder. Methods: Randomized control trial was carried out in General Surgery Department Shifa International Hospital for a period of 1 year from October 2017 to October 2018. All patients with acutely inflamed gallbladder admitted underwent laparoscopic cholecystectomy using conventional 4 port method. Applying Lottery method patients were sorted into two groups; (Group A) – without drain and (Group B) – with drain. Post operatively parameters of pain and total hospital stay were assessed. Data was entered into a standard SPSS sheet version 15.0. Results: Mean age of patients in without drain (group A) was 52.00±14.84 years and in with drain (group B) was 47.50±18.28 years. In without drain (group A), there were 9 (30.0%) males and 21 (70.0%) females, mean VAS was 2.37±1.22, 16.7% (5 of 60 patients) had pain, and mean hospital stay was 1.93+/-0.79 days. In with drain (group B), 13 (43.3%) were males and 17 (56.7%) were females, mean VAS was 3.2 +/-1.36, 36.7% (11 of 60 patients) had pain and mean hospital stay was 3.17+/- 0.87 days. The difference between the two groups for mean VAS was significant (P<0.05), for mean hospital stay was significant (P<0.05) but for pain frequency was insignificant (P>0.05). Conclusions: It has been concluded that without drain, more appropriate results have been obtained as compared to drain. Clinical Trial Number: NCT0434655

HRCT Spectrum in Initially COVID-19 RT-PCR Negative Patients

Objective: To analyze radiological spectrum of HRCT in COVID-19 patients, clinically symptomatic but initially having negative RT-PCR. Study Design: Prospective cross sectional descriptive study. Place and Duration of Study: Radiology and Medicine Department, DHQ Hospital Rawalpindi, from June to November 2020 Methodology: The study included 90 patients presenting with clinical symptoms of COVID-19 but with negative RT-PCR. All patients underwent chest computed tomography (CT). Patients with positive COVID-19 RT-PCR test or serology on subsequent repeat test were included in the study. Patients having non COVID-19 HRCT features with negative RT-PCR were excluded from the study. Results: Out of 90 symptomatic, RT-PCR negative patients, 7 had normal chest CT. According to BSTI classification, 50 patients showed classic, 11 had probable and 22 had indeterminate features. Despite supportive clinical and CT features, 17 (18.89%) patients had negative RT-PCR tests on subsequent testing. Unilateral changes were in 8 (8.9%) and bilateral in 75 (83.3%). Most common finding was mixed pattern of peripherally distributed GGN and bronchocentric nodules in 37 (41.1%) patients. Consolidations were in 19 (21.1%), pure ground glass haze in 13 (14.4%), crazy paving in 4 (4.4%), fuzzy bands and arcades in 7 (7.8%), and subtle gravitational GGH in 3 (3.3%) patients. CT-SS classified 69 (76.7%) patients as mild, 10 (11.1%) as moderate and 4 (4.4%) as severe disease. Conclusions: HRCT with CTSS is an important tool for diagnosing and prognosticating COVID-19 infection despite negative RT-PCR, timely identifying and isolating COVID-19 cohorts preventing cross infection and also aiding in prompt symptomatic management

Exploring diet, exercise, chronic illnesses, occupational stressors and mental well-being of healthcare professionals in Punjab, Pakistan

OBJECTIVE: This data set was compiled to assess mental well-being, dietary pattern and physical health parameters of health care professionals in Pakistan. DATA DESCRIPTION: The Warwick-Edinburgh mental well-being scale was first evaluated for the Pakistani population then used, along with other measures like body mass index, exercise and dietary habits to assess health and wellbeing of health care providers. The importance of the data lies in the fact that no previous records or data exists in our knowledge that used a subjective index to assess wellbeing in Pakistani population. Furthermore, this data may be used as part of a global analysis to find differences in well-being and health habits of health care providers in developing countries as opposed to developed countrie