2,983 research outputs found

    The influence of atmosphere on the performance of pure-phase WZ and ZB InAs nanowire transistors

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    We compare the characteristics of phase-pure MOCVD grown ZB and WZ InAs nanowire transistors in several atmospheres: air, dry pure N2_2 and O2_2, and N2_2 bubbled through liquid H2_2O and alcohols to identify whether phase-related structural/surface differences affect their response. Both WZ and ZB give poor gate characteristics in dry state. Adsorption of polar species reduces off-current by 2-3 orders of magnitude, increases on-off ratio and significantly reduces sub-threshold slope. The key difference is the greater sensitivity of WZ to low adsorbate level. We attribute this to facet structure and its influence on the separation between conduction electrons and surface adsorption sites. We highlight the important role adsorbed species play in nanowire device characterisation. WZ is commonly thought superior to ZB in InAs nanowire transistors. We show this is an artefact of the moderate humidity found in ambient laboratory conditions: WZ and ZB perform equally poorly in the dry gas limit yet equally well in the wet gas limit. We also highlight the vital role density-lowering disorder has in improving gate characteristics, be it stacking faults in mixed-phase WZ or surface adsorbates in pure-phase nanowires.Comment: Accepted for publication in Nanotechnolog

    Gender representation in Pakistani print media- a critical analysis

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    The key objective of this study was to examine the representations of men and women in print media in Pakistan. Gender role stereotyping and sexism in print media is not a low-profile gender issue as printed communication and contents still hold an important place in contemporary digital world. Keeping in view the importance of newspapers as the leading source of credible content/messages, this paper examined gender stereotyping and sexism in print media in Pakistan and attempted to highlight whether print media reproduces or challenges gender stereotypes and sexism? Keeping in view the complexity of sexism in print media, content and discourse analyses were performed on four widely read national newspapers. The findings have been placed within the socio-cultural context of Pakistani society and feminists theories. The study’s findings indicated that print media in Pakistan reinforces gender stereotypes and provide little challenge to gender stereotyped imagery of males and females

    An Invariant Dual-beam Snowflake Antenna for Future 5G Communications

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    A broadband snowflake antenna for future 5G and millimeter-wave communications is presented. The proposed antenna has a size of 8 × 5 mm 2 . The antenna consists of a central hexagon surrounded by a series of symmetrically placed smaller hexagons around it, resulting in broadband characteristics. The impedance bandwidth of the proposed antenna ranges from 25.284-29.252 GHz. The antenna has a gain of 3.12 dBi at 28 GHz and is more than 98% efficient. A distinct feature of the proposed antenna is its dual-beam radiation pattern. The two beams remain fixed at ±50° even if the frequency is varied with in its operating band. The proposed antenna is modelled on thin Rogers substrate which makes it very useful for future 5G smart phones

    Integration over matrix spaces with unique invariant measures

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    We present a method to calculate integrals over monomials of matrix elements with invariant measures in terms of Wick contractions. The method gives exact results for monomials of low order. For higher--order monomials, it leads to an error of order 1/N^alpha where N is the dimension of the matrix and where alpha is independent of the degree of the monomial. We give a lower bound on the integer alpha and show how alpha can be increased systematically. The method is particularly suited for symbolic computer calculation. Explicit results are given for O(N), U(N) and for the circular orthogonal ensemble.Comment: 12 pages in revtex, no figure

    Existing and Expected Service Quality of Grameenphone Users in Bangladesh

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    . The Grameenphone (GP) is a market leader in the telecommunication industry in Bangladesh. This study investigates the existing and expected service quality of Grameenphone users in Bangladesh. The Study reveals that there are significant gap between existing and expected perceived service network, 3G, customer care, physical facilities, billing cost, information service, mobile banking and GP offers. The study concludes that customer satisfaction is a dynamic phenomenon. Maintaining desired level of customer satisfaction requires corporate proactive responsiveness in accessing, building & retaining satisfied customers for sustainable competitive advantages in the marketplace

    To Perform Thrombolysis or Not: A Case of Acute Pancreatitis Presenting with Chest Pain and Transient Left Bundle Branch Block

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    A suspected case of acute coronary syndrome presented with new-onset left bundle branch and first-degree heart blocks. The decision to thrombolyse was reverted as ECG changes proved to be transient within fifteen minutes of presentation. Later on the patient was diagnosed with acute pancreatitis based on laboratory results of serum amylase, confirmed on radiological investigations

    Building forests for the future

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    Many governments have set ambitious targets for tree planting and increased woodland cover as a key part of actions to reach net‐zero carbon emissions by 2050. However, many uncertainties remain concerning how and where to expand tree cover, what species to plant, and how best to manage new plantations. Much contemporary forestry has been based on even‐aged monocultures, largely because of perceived advantages for timber production. However, in order to play a key role in climate change mitigation future forests will have to achieve timber production (and wider ecosystem service provision) alongside resilience to biotic and abiotic challenge. It is therefore crucial that appropriate informed decisions are made with regard to the structure, composition, and planning of future forests, in order to provide sustainable solutions that provide environmental, economic, and health benefits to society. Genetically diverse, mixed, and irregular forests, with their higher biodiversity and niche complementarity, are promising new forest configurations for regulating the water cycle, storing carbon, and delivering other goods and services. In the following discussion, we have used UK information to illustrate the benefits of mixed woodland versus monocultures and highlighted current issues related to government initiatives and policies for current and future forests. However, similar issues and problems are encountered globally

    Building forests for the future

    Get PDF
    Many governments have set ambitious targets for tree planting and increased woodland cover as a key part of actions to reach net‐zero carbon emissions by 2050. However, many uncertainties remain concerning how and where to expand tree cover, what species to plant, and how best to manage new plantations. Much contemporary forestry has been based on even‐aged monocultures, largely because of perceived advantages for timber production. However, in order to play a key role in climate change mitigation future forests will have to achieve timber production (and wider ecosystem service provision) alongside resilience to biotic and abiotic challenge. It is therefore crucial that appropriate informed decisions are made with regard to the structure, composition, and planning of future forests, in order to provide sustainable solutions that provide environmental, economic, and health benefits to society. Genetically diverse, mixed, and irregular forests, with their higher biodiversity and niche complementarity, are promising new forest configurations for regulating the water cycle, storing carbon, and delivering other goods and services. In the following discussion, we have used UK information to illustrate the benefits of mixed woodland versus monocultures and highlighted current issues related to government initiatives and policies for current and future forests. However, similar issues and problems are encountered globally

    Lafora Disease Masquerading as Hepatic Dysfunction

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    Lafora disease is fatal intractable progressive myoclonic epilepsy. It is frequently characterized by epileptic seizures, difficulty walking, muscle spasms, and dementia in late childhood or adolescence. We chronicle here an unusual case of an asymptomatic young male soccer player who presented with elevated liver enzymes. Neurological examination was unremarkable. The diagnostic workup for hepatitis, infectious etiologies, autoimmune disorders, hemochromatosis, Wilson\u27s disease, alpha-1 antitrypsin deficiency, and other related diseases was inconclusive. He subsequently underwent an uneventful percutaneous liver biopsy. Based on the pathognomonic histopathological findings, Lafora disease was considered the likely etiology. The present study is a unique illustration of this rare disorder initially manifesting with abnormal liver enzymes. It underscores the importance of clinical suspicion of Lafora disease in cases with unexplained hepatic dysfunction. Prompt liver biopsy and genetic testing should be performed to antedate the onset of symptoms in these patients
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