Harmonics Temporal Profile in High-Voltage Networks: Case Study

This chapter presents a case study about harmonics measurements in high-voltage networks. Measurements were conducted at two locations in the main interconnected system (MIS) of Oman. Voltage and current THDs were recorded for a period of 1 week. The power quality analyzer was set to record required data for a period of 1 week, and the observation period for each recorded value is 10 minutes. At the first location, the grid station (132/33) is feeding industrial as well as other customers. The second grid station (220/132/33 kV) is dedicated to large industrial customers including arc furnaces and rolling mills. The power quality analyzer was installed at the 132 kV side of power transformers at both locations. Recorded data are analyzed, and temporal harmonics profiles are studied. A clear temporal variation of harmonics similar to that of aggregate load and local voltage profiles was observed at the grid station feeding mixed residential and industrial loads. However, this correlation between system load and harmonics profile diminishes at the grid station dedicated for heavy industrial loads

A RADIOLOGICAL PROFILE OF FUNGAL SINUSITIS

  Objectives: To create a radiological profile of fungal sinusitis and determine the radiological differences between fungal and nonfungal sinusitis based on the presence of hyperattenuation, bony erosion, neo-osteogenesis, air-fluid level, and extrasinus extension.Methods: This is a retrospective, single-blind, case-control study involving the analysis of 119 computed tomography (CT) scans of the paranasal sinuses. Based on the histopathology, they were divided into cases comprising fungal sinusitis and controls of nonfungal sinusitis. Benign and malignant tumors and previously operated cases of fungal sinusitis were excluded from the study. The principal investigators were blinded to the diagnosis. The comparison parameters were hyperattenuation, the presence of air-fluid level, bone erosion, neo-osteogenesis, and extrasinus extension. Data was analyzed by Chi-square and Fischer exact t-test using SPSS 14.0 software and a p < 0.05 was considered significant.Results: Our study showed the presence of hyperattenuation, neo-osteogenesis, bone erosion, air-fluid level, extrasinus extension in 75.2%, 48.3%, 25.9%, 36.2%, and 6.9% of the cases and 13.1%, 16.4%, 6.6%, 9.8%, and 0 controls, respectively. All the parameters were statistically significant in cases when compared to controls.Conclusion: Hyperattenuation, neo-osteogenesis, air-fluid level, bone erosion, and extrasinus extension are the parameters on CT imaging that will help routinely assess and differentiate fungal sinusitis from nonfungal sinusitis with considerable accuracy, although, there is an overlap with malignancy when the parameter of bone erosion is considered as a differential diagnosis of chronic invasive fungal sinusitis. It reiterates the fact that history, clinical examination, and laboratory evaluation hold an important role in provisional diagnosis

Emergence of new SARS-CoV-2 Variant of Concern Omicron (B.1.1.529) - highlights Africa's research capabilities, but exposes major knowledge gaps, inequities of vaccine distribution, inadequacies in global COVID-19 response and control efforts

Nearly two years since the start of the SARS-CoV-2 pandemic, which has caused over 5 million deaths, the world continues to be on high COVID-19 alert. The World Health Organization (WHO), in collaboration with national authorities, public health institutions and scientists have been closely monitoring and assessing the evolution of SARS-CoV-2 since January 2020 (WHO 2021a; WHO 2021b). The emergence of specific SARS-CoV-2 variants were characterised as Variant of Interest (VOI) and Variant of Concern (VOC), to prioritise global monitoring and research, and to inform the ongoing global response to the COVID-19 pandemic. The WHO and its international sequencing networks continuously monitor SARS-CoV-2 mutations and inform countries about any changes that may be needed to respond to the variant, and prevent its spread where feasible. Multiple variants of the virus have emerged and become dominant in many countries since January 2021, with the Alpha, Beta, Gamma and Delta variants being the most prominent to date. (Table 1)

Recent smell loss is the best predictor of COVID-19 among individuals with recent respiratory symptoms

In a preregistered, cross-sectional study we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0-100 visual analog scales (VAS) for participants reporting a positive (C19+; n=4148) or negative (C19-; n=546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19- groups exhibited smell loss, but it was significantly larger in C19+ participants (mean±SD, C19+: -82.5±27.2 points; C19-: -59.8±37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC=0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss were more predictive than binary chemosensory yes/no-questions or other cardinal symptoms (e.g., fever). Olfactory recovery within 40 days of respiratory symptom onset was reported for ~50% of participants and was best predicted by time since respiratory symptom onset. We find that quantified smell loss is the best predictor of COVID-19 amongst those with symptoms of respiratory illness. To aid clinicians and contact tracers in identifying individuals with a high likelihood of having COVID-19, we propose a novel 0-10 scale to screen for recent olfactory loss, the ODoR-19. We find that numeric ratings ≤2 indicate high odds of symptomatic COVID-19 (4<10). Once independently validated, this tool could be deployed when viral lab tests are impractical or unavailable

Techno-Economic and Environmental Analysis of Renewable Mix Hybrid Energy System for Sustainable Electrification of Al-Dhafrat Rural Area in Oman

Affordable and clean energy for any rural community is crucial for the sustainable development of the community and the nation at large. The utilization of diesel-based power generation is one of the barriers to the sustainable development of these communities. Such generations require fuel that has a volatile market price and emits massive greenhouse gas emissions. This paper presents the design, modeling, and simulation of a hybrid power system for a rural area in the Sultanate of Oman that aims to reduce daily consumption of diesel fuel and greenhouse gas emissions. Hybrid Optimization of Multiple Energy Resources (HOMER) is utilized to model multiple energy mix hybrid systems and to propose the best optimal energy mix system for a selected community. In addition, Electrical Transient Analyzer Program (ETAP) software is employed to assess hybrid system operational performances, such as bus voltage profiles and active and reactive power losses. This study revealed that the PV–wind–diesel system is the optimal energy mix hybrid microgrid for the Al-Dhafrat rural area in Oman, with a net present cost of USD 14.09 million. Compared to the currently operating diesel-based system, the deployment of this microgrid can reduce the levelized cost of energy, diesel fuel consumption, and greenhouse gas emissions per year by 54.56%, 70.44%, and 70.40%, respectively. This study confirms that the Sultanate of Oman has a substantial opportunity to install a hybrid microgrid system for rural diesel-based communities to achieve sustainable development in the country

The Learning Organisation and Health Care Education

The ‘Learning Organisation’ is a concept first described by Peter Senge as an organisation where people continuously learn and enhance their capabilities to create. It consists of five main disciplines: team learning, shared vision, mental models, personal mastery and systems thinking. These disciplines are dynamic and interact with each other. System thinking is the cornerstone of a true learning organisation and is described as the discipline used to implement the disciplines. In a learning organisation, health care education aims to educate its members with up to date knowledge to produce competent and safe personnel, who can promote quality in health care services. In addition, there are some educational concepts and theoretical models, which are of relevance to the learning organisation, and can provide a framework for managerial decisions. The stages required to achieve the principles of a learning organisation will be described in detail. Moreover, in a proper culture which supports the learning organisation, members continuously learn to improve the environment and never remain passive recipients

Allergic Rhinitis in Relation to Food Allergies: Pointers to future research

Allergic rhinitis is a ubiquitous type of allergic reaction which results in significant costs to affected patients and their families. Although allergic rhinitis can coexist with other atopic conditions, the role of food allergies in the development of allergic rhinitis has not been well studied. This article explores relevant literature on this subject in order to identify gaps in the available body of knowledge and elucidate scope for further research

COVID-19 Associated Pneumonia: A review of chest radiograph and computed tomography findings

Medical imaging, including chest radiography and computed tomography, plays a major role in the diagnosis and follow-up of patients with COVID-19 associated pneumonia. This review aims to summarise current information on this topic based on the existing literature. A search of the Google Scholar (Google LLC, Mountain View, California, USA) and MEDLINE® (National Library of Medicine, Bethesda, Maryland, USA) databases was conducted for articles published until April 2020. A total of 30 articles involving 4,002 patients were identified. The most frequently reported imaging findings were bilateral ground glass and consolidative pulmonary opacities with a predominant lower lobe and peripheral subpleural distribution.   KEYWORDS COVID-19; Viral Pneumonia; Diagnostic Imaging; X-Ray Computed Tomography; Radiography;Review

Application of membrane distillation for the treatment of oil field produced water

Direct contact membrane distillation (DCMD) was investigated for the treatment of oil-field produced water using a hydrophobic polypropylene (PP) membrane with 0.2 mu m pore size. The DCMD performance was studied under different feed temperatures ranged from 40 degrees C to 80 degrees C while the cooling temperature was maintained at 23 degrees C. Increasing the feed water temperature resulted in a higher permeate water flux. Stable and reliable DCMD membrane performance was observed for all used membranes. The obtained results indicated the great potential of DCMD to treat hypersaline oil-field produced water with an overall rejection of salts higher than 99.9% and that of total organic carbon (TOC) greater than 93.3%. This was due to the presence of volatile organic compounds in oil-field water. Pre-treatment of produced water using 0.45 mu m filter did not show much effect on the DCMD performance. A slight gradual reduction of the permeate flux was observed due to fouling phenomenon. A simple washing the membrane with de-ionized water was found to be an effective method for cleaning the membrane and restoring the permeate flux indicating the absence of irreversible fouling

Outcome as a Measure of Quality of Care in Oncology: Experience at Sultan Qaboos University Hospital, Oman

Objectives: Measurement of outcomes is increasingly employed as an indicator of the quality of clinical care. The most commonly measured outcome in many clinical studies, especially in oncology, still remains the overall survival rate. Sultan Qaboos University Hospital (SQUH), Oman, is striving for excellence through quality management. In seeking continual improvement, quality measurement exercises have been initiated throughout the Hospital. We present the overall survival rate of four of the ten most common cancers diagnosed in Oman. Methods: The cancers included non Hodgkin’s lymphoma (NHL), Hodgkin’s lymphoma (HL), breast cancer, and stomach cancer. The studies were all retrospective and had been conducted previously. For present purposes, only the overall survival was compared with studies both from the region, and with bench-mark studies. Results: For NHL, with a median follow-up of 8 months, the 2-year overall survival rate was 64%; 90% for low risk, 55% for intermediate risk, and 15% for high risk groups. For HL, the 5-year overall survival rate was 64%; 76% for low risk and 42% for high risk. For breast cancer, the 5-year survival rate was 67%; percentages were 88%, 75% and 59% for Groups I, II, and III respectively. For gastric cancer, the 5-year survival rate was 16.5 %; 24% for the non-metastatic group. Conclusion: The outcome of patients with early stages and fewer adverse prognostic factors is comparable to what has been reported in the international literature; however, the outcome is inferior for patients presenting with advanced stage disease and several adverse prognostic factors