331 research outputs found

    Arc GIS based Interpretation of Heavy Metals in Soil Samples near Coastal Areas of Badin, Sindh, Pakistan

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    This study was aimed to assess the severity of heavy metal contamination in eastern coastal area of Pakistan. Agriculture lands near district Badin coastal area found contaminated due to mega surface canal drain network, carrying untreated industrial and municipal effluents along with pumped saline water. Thirty-two random soil samples were collected from different coastal areas. Arc Geographic Information System was used for spatial mapping. Soil samples from coastal areas of Badin contain average concentrations of heavy metals (mg/kg) as Hg 0.247Ā±0.207, Ni 2.622Ā±1.107,Zn 3.121Ā±0.929, Cu 0.059Ā±0.066, Fe 70.447Ā±1.163, Mn7.062Ā±1.251, Co 0.0167Ā±0.033,Cr0.799Ā±0.718

    Risk mitigation of poor power quality issues of standalone wind turbines:An efficacy study of synchronous reference frame (SRF) control

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    This paper validates and presents the efficiency and performance of Synchronous Reference Frame (SRF) control as a mitigating control in managing risks of high volatility of electric current flows from the wind turbine generator to the distributed load. High volatility/fluctuations of electricity (high current, voltage disturbance) and frequency are hazards that can trip off or, in extreme cases, burn down a whole wind turbine generator. An advanced control scheme is used to control a Voltage Source Converter (VSC)-based three-phase induction generator with a Battery Energy Storage System (BESS). For the purpose of risk mitigation of harmonics, this scheme converts three-phase input quantity to two-phase Direct Current (DC) quantity (dq) so that the reactive power compensation decreases the harmonics level. Thus, no other analog filters are required to produce the reconstructed signal of fundamental frequency. In this paper, the values of Proportional Integral (PI) regulators are calculated through the “MONTE CARLO” optimization tool. Furthermore, risk analysis is carried out using bowtie, risk matrix and ALARP (as low as reasonably practicable) methods, which is the novelty based on the parametric study of this research work. The results reveal that by inducting proposed SRF control into the Wind Energy Conversion System (WECS), the risks of high fluctuations and disturbances in signals are reduced to an acceptable level as per the standards of IEEE 519-2014 and EN 50160. The proposed work is validated through running simulations in MATLAB/Simulink with and without controls

    Energy Conservation Techniques to Mitigate the Power Shortage Problem in Pakistan (Case Studies)

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    The main objective of this research paper is to show benefits of different energy conservation techniques. As a first case study, I performed analysis on University of Gujrat, electrical power system. This case study involves analysis of motors and tube lights installed at the pumping stations and in Engineering Block of UOG respectively, with the help of energy analyzer before and after the installation of required rating capacitors. Power system analysis also done which includes power distribution system losses for example line losses and copper losses of different rating transformers of UOG. Cost and payback period calculation had been done. Second case study is performed on 11 KV Ali Park and Rachna Town feeders to show fruitful results obtained by implementing rehabilitation techniques on the above said feeders. The results showed by adopting energy conservation techniques not only energy is conserved, it also brings other benefits

    Implementation of Nanogrids for Future Power System

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    Microgrid is a new technology in power generation and this system is used to provide power and heat to its local area, such as cogeneration systems and renewable energy (wind turbines, photovoltaic cells, etc.). They are preferred for medium or high power applications. Nanogrid most likely to be used in small local loads for rural area as they will be more economic then the normal grid power system. Nano grids can operate independently or be connected to the mains and most likely the internal voltage can be utilized as ac or dc. In this research paper a small scale microgrid system is proposed for smart homes called "Nanogrid". Each houses have small electrical power system from them can be shared among houses. If it uses a DC system instead of a general AC system, it can reduce energy loss of inverter because each generator doesnā€™t need an inverter. Furthermore, it can continue to provide a power supply when blackout occurs in the bulk power system. A model of a nanogrid is developed to simulate the operation of the centralized power control. Finally a Simulink model is presented for small houses power range 90-285 KW

    Expression of anaplastic lymphokinase and HER2/neu immunostaining in patients with breast carcinoma

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    Background: The diagnosis and prognosis of breast cancer is done with various immunomarkers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2/neu), and Ki-67. The diagnostic utility of Anaplastic Lymphokinase (ALK) and HER2/neu should be explored for better management of breast carcinoma patients. So, the present study was designed to determine the expression of immunostaining with ALK and HER2/neu in patients with breast cancer and to compare the association of ALK expression and HER2/neu with clinicopathological parameters.Methods: This is a cross sectional multicenter study carried out from October 2016 to March 2017. A total of 140 subjects having breast carcinoma by using non-probability purposive sampling technique were selected. After taking informed consent, tissue samples were taken from received specimen of mastectomy for hematoxylin and eosin stain. The immunohistochemistry for ALK and HER2/neu were assessed on the paraffin blocks of the tumor.Results: Out of total 140 cases invasive ductal carcinoma (89%), invasive lobular carcinoma (8%), invasive medullary carcinoma (2.1%) and papillary carcinoma (0.7%) were seen. ALK expression was positive in 81 patients (58%) while HER2/neu expression was positive in 53 cases (38%). Significant association was observed between ALK expression with histological grade, lymph node involvement, skin involvement and necrosis. There was also a significant association was seen between HER2/neu expression with lymph node metastasis and necrosis.Conclusions: Present study shows higher expression of ALK when compared to HER2/neu expression in breast cancer patients

    The diagnostic utility of ancillary CD117 immunomarker compared with cell block cytology of thyroid lesions based on Bethesda grading system

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    Background: This is a cross sectional multicenter study carried out from July 2017 to December 2017. The aim of the present study is to evaluate the fine needle aspiration cytology and cell block of thyroid lesions on the basis of Bethesda grading system. Also, expression of CD117 immunostaining in thyroid lesions was evaluated. Finally, the results of cell block were compared with expression of CD117 immunomarker for diagnostic confirmation of different thyroid lesions.Methods: Total one hundred (100) patients presenting with thyroid swelling underwent fine needle aspiration, cell block preparation to diagnose and categorize thyroid lesion on the basis of Bethesda grading system and finally immunostaining with CD117 was carried out.Results: FNAC results showed 71% patients with benign thyroid morphology and about 23% cases were categorized as atypical to fairly malignant. In cell block study benign lesions diagnosed were 77%, 17% cases as suspicious and 6% were malignant thyroid nodules. Whereas expression of ancillary CD117 immunomarker, confirmed 83% as benign lesions and 17% cases as malignant. Overall ancillary CD117 immunomarker established the better diagnosis to manage and differentiate thyroid lesions.Conclusions: Cell block results are more accurate than FNAC in thyroid patients. The CD117 immunomarkers can be used as better diagnostic tool for confirmation of thyroid lesions and thus it can reduce unnecessary surgical intervention

    Efficient Advanced Encryption Standard for Securing Cognitive Radio Networks

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    During the last decade, the CR (Cognitive Radio) came into view as a major wireless technology to resolve the issue of spectrum secrecy and efficient spectrum utilization. However, due to unlicensed (secondary) users, there are various security threats to the CRN (Cognitive Radio Networks). Some malicious users may access the CRN and mislead the secondary users to vacate the occupied channel, which may stop the communication. In this work, we propose a new cryptographic-based algorithm, CRAES (Cognitive Radio-Advanced Encryption Standard), inspired by the traditional AES to secure the CRN. The data of the primary and secondary users is encrypted at the transmitter and decrypted at the receiver. Unlike the conventional AES, we introduce the data-dependent key-generation and shift-rows process. We also reduce the rounds of AES from 10-6 to improve the computational efficiency without compromising the overall security. The experimental results demonstrate the effectiveness of the proposed CR-AES in terms of better security, reliability, and computational efficiency

    Diversity, urban space and the right to the provincial city

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    Using three vignettes of the same physical space this article contributes to understanding of how the right to the city is contested in provincial England in the early twenty-first century. Oral history and ethnographic material gathered in Peterborough between 2010 and 2012 are drawn on to shed new light on the politics of diversity and urban space. This highlights the multiple place attachments and trans-spatial practices of all residents, including the white ethnic majority, as well as contrasting forms of active intervention in space with their different temporalities and affective intensities. The article carries its own diversity politics, seeking to reduce the harm done by racism through challenging the normalisation of the idea of a local, indigenous population, left out by multiculturalism. It simultaneously raises critical questions about capitalist regeneration strategies in terms of their impact both on class inequality and on the environment
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