288 research outputs found

    An Analysis of Renewable Energy Usage by Mobile Data Network Operators

    Get PDF
    The exponential growth in mobile data traffic has resulted in massive energy usage and therefore has increased the carbon footprint of the Internet. Data network operators have taken significant initiatives to mitigate the negative impacts of carbon emissions (CE). Renewable Energy Sources (RES) have emerged as the most promising way to reduce carbon emissions. This article presents the role of renewable energy (RE) in minimizing the environmental impacts of mobile data communications for achieving a greener environment. In this article, an analysis of some selected mobile data network operators’ energy consumption (EC) has been presented. Based on the current statistics of different mobile network operators, the future energy values are estimated. These estimations of carbon emissions are based on the predicted data traffic in the coming years and the percentage consumption of energy from renewable sources by the network operators. The analysis presented in this article would be helpful to develop and implement energy policies that accelerate the process of increasing the renewable shares in total energy requirements. Incrementing the share of renewable energy in total energy requirements can be a way forward to reach Goal 7 of the United Nations Sustainable Development Goals (SDGs)

    Association between hypodontia and angles malocclusion

    Get PDF
    Abstract This study was planned to determine the prevalence of hypodontia in permanent dentition and to test whether an association was present between hypodontia and Angle\u27s malocclusion. The retrospective study was conducted at a tertiary care hospital, Karachi, and comprised record of all patients visiting the orthodontic clinics of the hospital from 2005 to 2015. Orthodontic records of 790(79%) subjects, including 189(23.9%) males and 601(76.1%) females, were reviewed. Their mean age was 17 ± 5.06 years. A tooth was considered missing if no evidence of tooth germ was observed on orthopantomograms and dental casts. The total sample was distributed into three groups on the basis of Angle\u27s classification. Chi-square test was applied to determine an association between hypodontia and Angle\u27s malocclusion. Tooth agenesis was observed in 34(4.3%) and a statistically significant difference was found between the genders (p=0.005). A positive association was found between hypodontia and malocclusion groups. Higher frequency of missing teeth was seen in Class III malocclusion which indicates a great need for orthodontic treatment as it has a psychosocial impact on the quality of life

    Enhancing properties of iron and manganese ores as oxygen carriers for chemical looping processes by dry impregnation

    Get PDF
    The use of naturally occurring ores as oxygen carriers in CLC processes is attractive because of their relative abundance and low cost. Unfortunately, they typically exhibit lower reactivity and lack the mechanical robustness required, when compared to synthetically produced carriers. Impregnation is a suitable method for enhancing both the reactivity and durability of natural ores when used as oxygen carriers for CLC systems. This investigation uses impregnation to improve the chemical and mechanical properties of a Brazilian manganese ore and a Canadian iron ore. The manganese ore was impregnated with Fe2O3 and the iron ore was impregnated with Mn2O3 with the goal of forming a combined Fe/Mn oxygen carrier. The impregnated ore’s physical characteristics were assessed by SEM, BET and XRD analysis. Measurements of the attrition resistance and crushing strength were used to investigate the mechanical robustness of the oxygen carriers. The impregnated ore’s mechanical and physical properties were clearly enhanced by the impregnation method, with boosts in crushing strength of 11–26% and attrition resistance of 37–31% for the impregnated iron and manganese ores, respectively. Both the unmodified and impregnated ore’s reactivity, for the conversion of gaseous fuel (CH4 and syngas) and gaseous oxygen release (CLOU potential) were investigated using a bench-scale quartz fluidised-bed reactor. The impregnated iron ore exhibited a greater degree of syngas conversion compared to the other samples examined. Iron ore based oxygen carrier’s syngas conversion increases with the number of oxidation and reduction cycles performed. The impregnated iron ore exhibited gaseous oxygen release over extended periods in an inert atmosphere and remained at a constant 0.2% O2 concentration by volume at the end of this inert period. This oxygen release would help ensure the efficient use of solid fuels. The impregnated iron ore’s reactivity for CH4 conversion was similar to the reactivity of its unmodified counterpart. The unmodified manganese ore converted CH4 to the greatest extent of all the samples tested here, while the impregnated manganese ore exhibited a decrease in reactivity with respect to syngas and CH4 conversion.EPSR

    Syntheses and crystal structures of mixed-ligand copper(II)–imidazole–carboxylate complexes

    Get PDF
    Crystallographic data for the structures in this paper have been deposited with the Cambridge Crystallographic Data Center, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK. Copies of the data can be obtained free of charge on quoting depository numbers CCDC-1543434 (1), CCDC-1543435 (2) and CCDC-1543436 (3) (Fax:+44-1223-336–033; E-mail: [email protected]; http://www.ccdc.cam.ac.uk). Supplemental data for this article can be accessed at https://doi.org/10.1080/00958972.2018.1460471.Peer reviewedPostprin

    HIV/AIDS in Pakistan: the battle begins

    Get PDF
    Pakistan, the second most populous Muslim nation in the world, has started to finally experience and confront the HIV/AIDS epidemic. The country had been relatively safe from any indigenous HIV cases for around two decades, with most of the infections being attributable to deported HIV positive migrants from the Gulf States. However, the virus finally seems to have found a home-base, as evidenced by the recent HIV outbreaks among the injection drug user community. Extremely high-risk behavior has also been documented among Hijras (sex workers) and long-distance truck drivers. The weak government response coupled with the extremely distressing social demographics of this South-Asian republic also helps to compound the problem. The time is ripe now to prepare in advance, to take the appropriate measures to curtail further spread of the disease. If this opportunity is not utilized right now, little if at all could be done later

    Compact Polarization Diversity Antenna for 28/38 GHz Bands

    Get PDF
    In this paper, design and analysis of a millimeter wave dual- and dual-polarized antenna for 5G millimeter communications system is presented. The proposed design has a compact structure with size of 5 × 5 mm 2 . It consists of a rectangular patch with a crossed-slot etched off in the patch to reduce the interference between the two targeted 5G bands of 28 and 38 GHz. To achieve dual polarization performance, the radiating patch is fed by two different 50-Ω microstrip transmission lines. The antenna has -10dB impedance bandwidths of 2.6GHz (26.8-29.4 GHz) and 2.5GHz (37.7-40.2GHz) to cover 28/38 GHz mobile communication bands respectively. The antenna has the merits of miniaturized dimensions, stable broadside radiation patterns with high gains and low cross polarization in both bands of operation

    Perceptions about the cause of schizophrenia and the subsequent help seeking behavior in a Pakistani population – results of a cross-sectional survey

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>There is a cultural variability around the perception of what causes the syndrome of schizophrenia. Generally patients with schizophrenia are considered dangerous. They are isolated and treatment is delayed. Studies have shown favorable prognosis with good family and social support, early diagnosis and management. Duration of untreated psychosis is a bad prognostic indicator. We aimed to determine the perceptions regarding the etiology of schizophrenia and the subsequent help seeking behavior.</p> <p>Methods</p> <p>This cross-sectional study was carried out on a sample of 404 people at the out patient departments of Aga Khan University Hospital Karachi. Data was collected via a self-administered questionnaire. Questions were related to a vignette of a young man displaying schizophrenic behavior. Data was analyzed on SPSS v 14.</p> <p>Results</p> <p>The mean age of the participants was 31.4 years (range = 18–72) and 77% of them were males. The majorities were graduates (61.9%) and employed (50%). Only 30% of the participants attributed 'mental illness' as the main cause of psychotic symptoms while a large number thought of 'God's will' (32.3%), 'superstitious ideas' (33.1%), 'loneliness' (24.8%) and 'unemployment' (19.3%) as the main cause. Mental illness as the single most important cause was reported by only 22%. As far as management is concerned, only 40% reported psychiatric consultation to be the single most important management step. Other responses included spiritual healing (19.5%) and Sociachanges (10.6) while 14.8% of respondents said that they would do nothing. Gender, age, family system and education level were significantly associated with the beliefs about the cause of schizophrenia (p < 0.05). While these variables plus 'religious inclination' and 'beliefs about cause' were significantly associated with the help seeking behavior of the participants.</p> <p>Conclusion</p> <p>Despite majority of the study population being well educated, only a few recognized schizophrenia as a mental illness and many held superstitious beliefs. A vast majority of Pakistanis have non-biomedical beliefs about the cause of schizophrenia. Their help seeking behavior in this regard is inappropriate and detrimental to the health of schizophrenic patients. Areas for future research have been identified.</p

    The Privatization of the Public Industrial Enterprises in Pakistan

    Get PDF
    The present study examines the case for the privatization of public industrial enterprises in Pakistan, where the term 'privatization' is defined as a transfer of ownership from the public to the private sector. The focus of analysis is to compare the efficiency levels in public and private enterprises producing similar goods. It has been shown that, in general, allocative and productive efficiency is primarily associated with the quality of management rather than with the locus of ownership. The study corrects a popular misconception by showing that as some public enterprises showed losses, most of them made sufficiently large profits, and that their high rates of profit cannot be attributed to the high rates of protection. Indeed, the average rate of effective protection for industries in the public sector, as a rule, is lower than that for the industries in the private sector. Furthermore, the popular argument that the public enterprises indulge in monopolistic practices cannot be sustained because they, in fact, face competition both from the imports and the private investor; and because they typically enjoy high rates of capacity utilization. The fiscal argument in favour of privatization is also weak, because profit rates in most public enterprises tend to exceed the interest rate on public debt, so that their divestiture may increase the fiscal deficit rather than reduce it We also argue that privatization may not lay the foundation of the so-called people's capitalism in view of low incomes of the workers and the practice of insider-trading in the stock exchanges of Pakistan. At any rate, the value-added by the public industrial enterprises is such a small proportion of the Gross Domestic Product that not many growth points can be added on account of privatization.

    Enhancing Smart Cities with IoT and Cloud Computing: A Study on Integrating Wireless Ad Hoc Networks for Efficient Communication

    Get PDF
    شهدت المدن الذكية تطورا جوهريا زاد من امكانياتها بشكل كبير .في الواقع ، لقد أتاحت التطورات الحديثة في انترنت الاشياء (IOT) فرصا جديدة من خلال حل عدد  من المشاكل الحرجة والتي ادت الى ابتكار المدن الذكية بالاضافة الى انشاء و حوسبة الخدمات و التطبيقات المتطورة للعديد من  المجاميع المطورة في المدينة . من اجل تعزيز تنمية المدن الذكية بأتجاه التواصل و المشاركة ،تركز هذه الدراسة على التطور في مجال المعلوماتية في ضوء انترنت الاشياء (IOT) و الحوسبة السحابية (CC) .جمعت بيانات انترنت الاشياء والتي تخص المدن الذكية بشكل متجانس . اصبح انترنت الاشياء الذي يسمح بتواصل الاشخاص مع بعضهم ممكنا باستخدام الذكاء الاصطناعي .بناءا على ذلك ،استخدمنا (ARF) في حسابات الذكاء الاصطناعي .للتبسيط ،ننصح باستخدام تخصيص اصول الالة الافتراضية للحوسبة السحابية التكيفية (ACC-VMRA ) .لتاكيد جدواها ،سنفحص و نضاعف كيفية تطبيق تطورات انترنت الاشياء (IOT ) و الحوسبة السحابية (CC) في المدن الذكية.تظهر نتائج التجربة ان حساب التحسين الموصى به اكثر انتاجية من الطرق الاخرى المستخدمة حاليا.Smart cities have recently undergone a fundamental evolution that has greatly increased their potentials. In reality, recent advances in the Internet of Things (IoT) have created new opportunities by solving a number of critical issues that are allowing innovations for smart cities as well as the creation and computerization of cutting-edge services and applications for the many city partners. In order to further the development of smart cities toward compelling sharing and connection, this study will explore the information innovation in smart cities in light of the Internet of Things (IoT) and cloud computing (CC). IoT data is first collected in the context of smart cities. The data that is gathered is uniform. The Internet of Things, which enables gadgets to connect with one another mostly without human involvement, is made possible by AI. In line with this, The Ad Hoc Routing Function (ARF) AI computation is used for multi-rule simplification, the use of Adaptive Cloud Computing Virtual Machine Asset Allotment Technique (ACC-VMRA) is advised. To confirm its viability, the applied developments of IoT and CC in smart cities is examined and duplicated. The experiment results show that the recommended enhancement calculation is more productive than other currently used methods
    corecore