1,299 research outputs found

    Analysis on Wearable Antenna Performance on Different Radiating Elements for GPS Application

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    This paper presents a study on the performance of self-manufactured electro-textile (SME-T) antenna that was designed at 1.575 GHz based on the allocated spectrum for Global Positioning System (GPS) application. However, due to its known low-conductivity characteristic, the ability of the newly developed material to perform as a good antenna shall be verified. Therefore, the performance of the antennas are compared and studied with respect to established materials such as adhesive copper tape and commercial conductive fabric named SHIELDITTM as the radiating elements. Here, four e-textile antennas having approximately the same size are fabricated and tested. The performance of all antennas, in terms of return loss, radiation pattern, gain, and efficiency; manufactured by using different radiating elements, such as copper, SHIELDITTM and SME-T fabricated on polyester fabric as the substrate are analyzed. The measured return loss and radiation pattern of SME-T antenna has proven that the antenna is well suited for wearable application. The measured antenna gain and efficiency of 0.61 dB and 25.95% are obtained and it is proven that the fabricated SME-T antenna can act as a receiving antenna designed for GPS applications which requires low gain antenna for passive monitoring

    A rapid method for preparation of sarcolemma from frog skeletal muscle

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    A rapid method for the preparation of sarcolema from frog skeletal muscle has been described. The purified cell segments were transparent and devoid of contractile material. The Na+, K+ -ATPase and 5'-nucleotidase activities in sarcolemma purified by this method were comparable to those reported for sarcolemmal preparations purified by density gradient centrifugation. The preparation also possessed acid phosphatase, alkaline phosphatase and K+ -activated, ouabain-sensitive p-nitrophenyl phosphatase activities. The cholesterol to phospholipid ratio of the sarcolemma was 0.33, indicating its high purity; further, the preparation was free from mitochondria and contractile proteins

    Nanoparticles Synergistic Effect with Various Substrate Pretreatment and their Comparison on Biogas Production from Algae Waste

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    Algae waste is one of the potential substrates for biogas and biohydrogen production and can comprehend multiple benefits of waste treatment and resource utilization. In view of the key bottlenecks such as low substrate degradation rate and poor productivity of algae waste production process, this study analyzes the combined effect of two metallic and metallic oxide nanoparticles with different substrate pretreatment methods (autoclave, ultrasonic, and microwave methods) to investigate the effect of anaerobic digestion of green algae (Enteromorpha). The results showed that out of the three pretreatment methods, microwave pretreatment and nanoparticles' synergistic effect significantly increases biogas production. The microbial community composition at the phylum level was analyzed. It was observed that the Firmicutes were most abundant across all samples. The relative abundance of Firmicutes for control, Ni NPs + MW, Co NPs + MW, and Fe3O4 NPs + MW groups were 51.78, 70.37, 75.77, and 83.93%,      respectively. The second most abundant was of Bacteroidetes that also contributes to hydrogen production. This relatively high abundance of Firmicutes and Bacteroidetes promises its potential applications in a hydrogen production facility. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

    Normal human breast xenografts activate N-nitrosodimethylamine: identification of potential target cells for an environmental nitrosamine.

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    Normal human breast tissue maintained as xenografts in female Balb/c (nu/nu) athymic mice is capable of metabolising N-nitrosodimethylamine (NDMA) to active intermediates that will react with DNA. Administration of NDMA to mice with slow-release implants of 17 beta-oestradiol which provide human physiological (luteal phase) circulating oestrogen levels and increase cell proliferation in the xenograft (Laidlaw et al., 1992), leads to an apparent increase in the extent of reaction with DNA compared to controls without oestrogen implants. In mice with oestrogen implants, measurements of the amounts of the promutagenic lesion, O6-methyl-2'-deoxyguanosine formed in DNA clearly indicated a dose related increase in the extent of reaction. Detection of O6-methyl-2'-deoxyguanosine using immunohistochemical procedures revealed that the nuclei of cells of the glandular epithelium, supportive tissue and adipose tissue, in decreasing order of prevalence, were positively stained for the presence of this DNA lesion. Epithelial cells, which are the putative target cells for carcinogenesis in the breast, are therefore prone to promutagenic damage as a result of exposure to an environmental nitrosamine

    Cancer Patterns in Karachi Division (1998-1999)

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    Objective: A minimal cancer incidence data for Karachi, the largest city of Pakistan, is being presented here, for the years 1998-1999. The city has a population of 9,802,134; males 5,261,712 (52.6%) and females 4,540,422 (47.4%); census 19981. Methodology: A predominantly mixed (passive and active) registration system has evolved in Karachi, the data sources being the hospitals within the Karachi Division. The reported/retrieved cancer data sets at the Karachi Cancer Registry are checked, coded, computerised in an analytical format and analysed. Results: The incident cancer cases registered in Karachi, during the 2-year period, 1st January 1998 to 31st December 1999 were analysed. The age-standardised incidence rate (ASR) of cancer, all sites was 132.4/100,000 for the males. Cancer of the lung 10.8%; ASR 17.3 was the most frequently recorded malignancy, followed by oral cavity 10.5%; ASR 13.2 and larynx 5.0%; ASR 7.4. The age-standardised incidence rate (ASR) of cancer, all sites was 133.0/100,000 in the females. Cancer of the breast, 32.0%; ASR 40.7 was the most frequently recorded malignancy, followed by oral cavity 8.1%; ASR 11.7 and gall bladder 3.6%; ASR 5.5. Conclusion: The present data has been calculated with an estimated 15-20% probable under ascertainment. Tobacco-associated cancers in Karachi were responsible for 38.3% of the tumours diagnosed amongst the males. Two principal cancers, breast and oral cavity were responsible for 40.1% of the cancers in females. A rare finding was the high incidence of gall bladder cancer in the females. At present it is difficult to determine whether this indicates a genuine high risk or a selection bias. A continuous process of cancer registration to study the trends in the incidence and an adequate cancer control program are possible and essential for Pakistan and can be based on the pattern being practiced in Karachi

    Characterization of Lens Antenna in Wireless Communication System

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    The focus of this paper is to design lens and analyze the lens behavior in lens antenna. This lens antenna is designed to enhance the gain of conventional antenna. A few factors that influenced the design of lens and gain of lens antenna is investigated. CST software is used to design the lens. At the end of this experiment, the lens gain increased from 8.782 dB to 11.07 dB

    A Novel 24-GHz Miniaturized Flexible Rectifier for Wireless Energy Harvesting

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    In this research article, the design and fabrication of a miniaturized flexible rectifier at 24 GHz for wireless power transfer to wearables is presented. The proposed circuit consists of a shunt topology rectifier including a single stub impedance matching network. Conventional PCB fabrication technique is used for the prototyping of the proposed flexible rectifier. It has a total footprint of 5.29 cm². The proposed rectifier exhibits a good trade-off between compactness and RF-to-DC conversion efficiency. The implementation on a very thin substrate (130 µm) makes it durable for wearables applications. Experimental results of the proposed rectifier show an output DC voltage of 2.0 V across an optimal load resistance of 250 Ω and measured RF-DC conversion efficiency of 23% for an input power of 17 dBm at 24 GHz

    Thinking about Later Life: Insights from the Capability Approach

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    A major criticism of mainstream gerontological frameworks is the inability of such frameworks to appreciate and incorporate issues of diversity and difference in engaging with experiences of aging. Given the prevailing socially structured nature of inequalities, such differences matter greatly in shaping experiences, as well as social constructions, of aging. I argue that Amartya Sen’s capability approach (2009) potentially offers gerontological scholars a broad conceptual framework that places at its core consideration of human beings (their values) and centrality of human diversity. As well as identifying these key features of the capability approach, I discuss and demonstrate their relevance to thinking about old age and aging. I maintain that in the context of complex and emerging identities in later life that shape and are shaped by shifting people-place and people-people relationships, Sen’s capability approach offers significant possibilities for gerontological research

    Randomized Control Trials and Qualitative Evaluations of a Multifaceted Programme for Women in Extreme Poverty: Empirical Findings and Methodological Reflections

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    This paper sets out to synthesize key lessons from studies using alternative methodologies to impact assessment. Drawing on Sen’s capability approach as a conceptual framework, it analyses two pairs of impact assessments which were carried out in West Bengal and Sindh around the same time and within close proximity to each other. Each pair consisted of a randomized control trial and a qualitative assessment of attempts to pilot BRAC’s approach to transferring assets to women in extreme poverty. The paper reports on the findings of these studies, their strategies for establishing their claims about causality and the information base they drew on to establish these claims. It finds that not only did the RCTs fail to meet their own criteria for establishing causality, but they also provided very limited explanation for the patterns of outcomes observed. Such information formed the substance of the qualitative studies. The paper concludes that greater use of mixed methods could help to offset some of limitations of RCTs and to place their findings on much firmer ground

    Distinction between the Poole-Frenkel and tunneling models of electric field-stimulated carrier emission from deep levels in semiconductors

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    The enhancement of the emission rate of charge carriers from deep-level defects in electric field is routinely used to determine the charge state of the defects. However, only a limited number of defects can be satisfactorily described by the Poole-Frenkel theory. An electric field dependence different from that expected from the Poole-Frenkel theory has been repeatedly reported in the literature, and no unambiguous identification of the charge state of the defect could be made. In this article, the electric field dependencies of emission of carriers from DX centers in AlxGa1-xAs:Te, Cu pairs in silicon, and Ge:Hg have been studied applying static and terahertz electric fields, and analyzed by using the models of Poole-Frenkel and phonon assisted tunneling. It is shown that phonon assisted tunneling and Poole-Frenkel emission are two competitive mechanisms of enhancement of emission of carriers, and their relative contribution is determined by the charge state of the defect and by the electric-field strength. At high-electric field strengths carrier emission is dominated by tunneling independently of the charge state of the impurity. For neutral impurities, where Poole-Frenkel lowering of the emission barrier does not occur, the phonon assisted tunneling model describes well the experimental data also in the low-field region. For charged impurities the transition from phonon assisted tunneling at high fields to Poole-Frenkel effect at low fields can be traced back. It is suggested that the Poole-Frenkel and tunneling models can be distinguished by plotting logarithm of the emission rate against the square root or against the square of the electric field, respectively. This analysis enables one to unambiguously determine the charge state of a deep-level defect
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