2,079 research outputs found

    Smart Loads for Voltage Control in Distribution Networks

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    This paper shows that the smart loads (SLs) could be effective in mitigating voltage problems caused by photovoltaic (PV) generation and electric vehicle (EV) charging in low-voltage (LV) distribution networks. Limitations of the previously reported SL configuration with only series reactive compensator (SLQ) (one converter) is highlighted in this paper. To overcome these limitations, an additional shunt converter is used in back-to-back (B2B) configuration to support the active power exchanged by the series converter, which increases the flexibility of the SL without requiring any energy storage. Simulation results on a typical U.K. LV distribution network are presented to compare the effectiveness of an SL with B2B converters (SLBCs) against an SLQ in tackling under- and over-voltage problems caused by EV or PV. It is shown that SLBCs can regulate the main voltage more effectively than SLQs especially under overvoltage condition. Although two converters are required for each SLBC, it is shown that the apparent power capacity of each converter is required to be significantly less than that of an equivalent SLQ

    Constitutional Legitimacy: Sharia Law, Secularism and the Social Compact

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    This article considers the general points relating to the application of Sharia law which challenges legislators in the political instability of a number of Middle Eastern countries. The question explored is how governments of these countries who are facing discontent can work towards constitutional governance. As an example comparison is made between the Islamic Republic of Pakistan and Indonesia with the largest Muslim populations. In Pakistan an inherited Westminster Parliamentary system with a common law codified dated at the time of the British rule is supplemented by criminal penalties as present in the Hudood ordinances. These codes enforce punishments for some crimes and these were promulgated in the early 1980s during the reign of the Pakistani conservative military government. These different layers of jurisprudence do not accord with a uniform legal precedence and creates a clash between liberals and the fundamentalists who want an all pervasive Sharia law . The Pakistani legal canon of Islamic law has been restricted by the secular ideology of the state which has parallels in other Asian countries with a Muslim majority. However, there is an issue of compatibility of a secular ideology and the application of Sharia. It needs an exposition of thought that takes account of the enlightenment in Europe which led to the social contract theory in the 18th century. This theory rejects the narrow interpretation of divine authority and presents the jurist with a challenge to make modernize the laws. In recent times Muslim academics have adopted a critical approach against the tenets of conservatism in temporal Islam and called them unrepresentative of the true spirit of the Sharia. The present turmoil in the Arab countries has raised the question of legitimacy and the need arises to evaluate the principles of the Compact of Medina, which was proclaimed by the first Islamic state, and secondly, to enquire if the adoption of Sharia can be made contingent upon a consensus of popular sovereignty in order to make it binding in a contract between the ruler and the governed

    Utility and accuracy of primary and secondary ultrasonographic signs for diagnosing acute appendicitis in pediatric patients

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    Introduction Making an accurate diagnosis of acute appendicitis (AA) is vital to prevent the morbid complications associated with untreated AA. This is challenging in up to 30% of pediatric patients which is a significantly high number. Ultrasound (US) has been generally used as the initial mode of imaging in pediatric patients due to the lack of ionizing radiation. Given its variable accuracy, adjuvants such as secondary signs can be used to aid the radiologist in making an accurate diagnosis. Materials and methods Patients between the ages of two and sixteen years with acute abdominal pain suspicious for AA, who underwent right lower quadrant US between 2003 and 2016, were retrospectively identified. Corresponding computed tomography (CT) and histopathology findings were noted. Based on the presence of primary and secondary signs, results were classified into three groups to determine accuracy. Group 1 included all patients with a normal appendix or if the appendix was not visualized, no secondary signs were present. Group 2 patients were those in which the appendix was not clearly seen and they had one or more secondary signs of AA. Group 3 included all patients with primary signs of AA. The number of secondary signs and cases with perforated appendices were also correlated with sonographic accuracy. Results One thousand one hundred and fifteen patients met the inclusion criteria of which 29% had confirmatory AA. The positive appendectomy rate was 89% (337/380). Using a 3-category classification of US results, the sensitivity was 79%, specificity 97%, positive predictive value was 93%, negative predictive value was 91% and the overall accuracy was 91%. The presence of two or more secondary signs had a high likelihood of appendicitis. The perforation rate was 10% with the highest percentage seen in Group 2 patients. Conclusion Despite inescapable limiting factors, US should be used as first-line imaging for suspected appendicitis in pediatric patients especially since its accuracy rivals CT when the appendix is visualized. The use of secondary sonographic signs has solid potential to aid the radiologist in making an accurate diagnosis with our study demonstrating a proportional relationship between the number of secondary signs and the likelihood of true appendicitis. However, further investigation is needed to determine the individual accuracy of secondary signs and whether a certain combination of secondary signs has a higher association with appendicitis

    Frequency of Clinical Symptoms of Gastroesophageal Reflux Disease in Asthmatic Patients

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    Background: Gastroesophageal reflex is known as an acid reflex, is long term condition where stomach contents back into the oesophagus resulting in either symptoms or complications. GERD disease is caused by weakness or failure of the lower oesophageal sphincter. Symptoms include the acidic taste behind the mouth, heart burn, chest pain, difficult breathing and vomiting. Complication includes esophagitis, oesophageal strictures and barrettes oesophagus. Objective: The aim of this research was to introduce the symptoms of GERD disease in asthmatic patients and how these symptoms worsen the symptoms of asthma disease and what clinical pictures present with the asthmatic disease. Methodology: A designed performa was used to collect the data and after filling the performa, results were drawn and conclusion through the facts and the information given by patients. Results: In the present study among all 164 asthmatic patients, 70 (42.7%) patients showed dyspepsia, 58 (35.4%) were with chest burning, 23 (14%) were asking about chest pain, with acidic mouth taste were 39 (23.8%), 22 (13.4%) were feeling sore throat and 44 (26.8%) showed regurgitation reflex. Among these 164 patients 16 (9.8%) were smokers and 148 (90.2 %) were non-smokers. 47 (28.7%) were males and 117 (71.3%) were females. Conclusion: It is concluded that gastroesophageal reflux disease in asthmatic patients present symptoms of acidic mouth taste, chest burning, chest pain, dyspepsia, regurgitation reflex and sore throat

    Essential micro-foundations for contemporary business operations: top management tangible competencies, relationship-based business networks and environmental sustainability

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    Although various studies have emphasized linkages between firm competencies, networks and sustainability at organizational level, the links between top management tangible competencies (e.g., contemporary relevant quantitative-focused education such as big data analytics and data-driven applications linked with the internet of things, relevant experience and analytical business applications), relationship-based business networks (RBNs) and environmental sustainability have not been well established at micro-level, and there is a literature gap in terms of investigating these relationships. This study examines these links based on the unique data collected from 175 top management representatives (chief executive officers and managing directors) working in food import and export firms headquartered in the UK and New Zealand. Our results from structural equation modelling indicate that top management tangible competencies (TMTCs) are the key determinants for building RBNs, mediating the correlation between TMTCs and environmental sustainability. Directly, the competencies also play a vital role towards environmental practices. The findings further depict that relationship-oriented firms perform better compared to those which focus less on such networks. Consequently, our findings provide a deeper understanding of the micro-foundations of environmental sustainability based on TMTCs rooted in the resource-based view and RBNs entrenched in the social network theory. We discuss the theoretical and practical implications of our findings, and we provide suggestions for future research

    False-positive troponin elevation due to an immunoglobulin-G-cardiac troponin T complex: a case report.

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    Background: Troponin is a crucial biomarker for the diagnosis of an acute coronary syndrome (ACS). It rises in response to myocardial injury from significant acute myocardial ischaemia caused by obstructive coronary artery disease ['classical' myocardial infarction (MI)]. However, raised levels have also been noted in conditions not recognized as classical ACS. This may include MI with non-obstructed coronary arteries such as takotsubo cardiomyopathy and other acute or chronic conditions such as pulmonary embolus or chronic kidney disease. This is commonly labelled as a 'falsely elevated' troponin although there is some myocardial strain to explain the rise, such as an increase in cardiac oxygen demand. True 'falsely elevated' troponin, characterized by a persistent elevation in the absence of cardiac injury does occur and thought to be secondary to an immunoglobulin-troponin complex (macrotroponin). Case summary: A 53-year-old gentleman with a background of diabetes, hypertension, hypercholesterolaemia, and hepatitis B was admitted with chest pain and persistently elevated cardiac troponin T (cTnT) levels. Investigations revealed unobstructed coronary arteries and a structurally normal, well-functioning heart. Subsequent biochemical analysis found the persistently elevated cTnT secondary to macrotroponin T. Discussion: Macrotroponin, an immunoglobulin-troponin bound complex should be considered as a differential diagnosis when the biochemistry is not reflective of the clinical picture. Early recognition requires effective collaboration with the biochemistry laboratory for accurate diagnosis

    Acalypha indica Linn is a potential source of root-knot nematode infestation in cultivated fields

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    Acalypha indica L. is a commonly growing weed in India, which is also known as Indian Acalypha. These plants were growing as a weed in pots wherein okra was planted for experimental purpose. Infestation of the root-knot nematode, Meloidogyne incognita was observed on it. Soil and root samples were collected for analyses of nematode infestation. Roots of the infested plants were galled measuring gall index (GI) of 3-4. The population density of second stage juveniles (J2) in soil varies from 378-752/200cc soil and the roots were harboring 3876-7654 eggs/per root system. The root galling and presence of high population of nematode eggs and J2 revealed that A. indica can be a reservoir for M. incognita during non-host cropping and serve as a source of infestation to other hosts in the next cropping season. So, in the light of present findings growers are advised to be watchful for A. indica in their fields, and keep the field free from this weed to minimize the infestation of M. incognita in the next crop. 

    Enhancing supply chain innovation and operational agility through knowledge acquisition from the social media: A microfoundational approach

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    This paper presents an examination of the interlocks between knowledge acquisition from social media (KAfSM), organizational microfoundation structure and design (OMFSaD), supply chain innovation (SCI), and operational agility (OA). These interlocks were tested on data collected from 172 managers/directors/CEOs of 96 firms operating in nine manufacturing industry sectors in Malaysia. Our findings suggest that OMFSaD plays a key role when interlinked with KAfSM. Furthermore, OMFSaD is significantly associated with SCI and OA, and SCI significantly correlates with OA and partially mediates the relationship between OMFSaD and OA. Our study’s outcomes are consistent with our understanding of IT‐enabled organizational capabilities—thus contributing to dynamic capability theory—and suggest that KAfSM helps to revamp processes, routines, and business operations in frequently changing environments. In this paper, we draw implications for research and practice
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