Thermal Performance of an Air Heating Storing System

Owing to the lack of synchronization between the solar energy availability and the heat demands in a specific application, the energy storing sub-system is necessary to maintain the continuity of thermal process. The present work is dealing with an active solar heating storing system in which an air solar collector is connected to storing unit where this energy is distributed and provided to the heated space in a controlled manner. The solar collector is a box type absorber where the air flows between a number of vanes attached between the collector absorber and the bottom plate. This design can improve the efficiency due to increasing the heat transfer area exposed to the flowing air, as well as the heat conduction through the metal vanes from the top absorbing surface. The storing unit is a packed bed type where the air is coming from the air collector and circulated through the bed in order to add/remove the energy through the charging / discharging processes, respectively. The major advantage of the packed bed storage is its high degree of thermal stratification. Numerical solution of the packed bed energy storage is considered through dividing the bed into a number of equal segments for the bed particles and solved the energy equation for each segment depending on the neighbor ones. The studied design and performance parameters in the developed simulation model including, particle size, void fraction, etc. The final results showed that the collector efficiency was fluctuated between 55%-61% in winter season (January) under the climatic conditions of Misurata in Libya. Maximum temperature of 52ºC is attained at the top of the bed while the lower one is 25ºC at the end of the charging process of hot air into the bed. This distribution can satisfy the required load for the most house heating in Libya

An Evaluation of Machine Learning and Big Data Analytics Performance in Cloud Computing and Computer Vision

Although cloud computing is receiving a lot of attention, security remains a significant barrier to its general adoption. Cloud service users frequently worry about data loss, security risks, and availability issues. Because of the accessibility and openness of the huge volume of data amassed by sensors and the web throughout recent years, computer applications have seen a remarkable change from straightforward data processing to machine learning. Two widely used technologies, Big Data and Cloud computing, are the focus of worry in the IT industry. Enormous data sets are put away, handled, and broke down under the possibility of "Big Data." Then again, cloud computing centres around giving the framework to make such systems conceivable in a period and cash saving way. The objective of the review is to survey the Big Data Analytics and Machine learning ideal models for use in cloud computing and computer vision. The programmed data examination of enormous data sets and the production of models for the wide connections between data are the centre highlights of machine learning (ML). The usefulness of machine learning-based strategies for identifying threats in a cloud computing environment is surveyed and compared in this research

CT patterns among Covid-19 patients during the second wave: A single institute study

Background: The COVID-19 pandemic caused a worldwide dramatic loss of human life. The second wave of coronavirus showed a very rapid spread. Objective: This study aimed to retrospectively analyze the laboratory findings and chest computed tomography (CT) features in patients with suspected coronavirus disease (COVID-19) pneumonia during the second wave. Patients and methods: From November 2020 to February 2021, a total of 295 patients were admitted to our hospital with suspected COVID-19 pneumonia. They underwent multiple laboratory tests including (s. ferritin, CBC) as well as non–contrast CT. Only 144 patients had PCR results available. The CT findings were reported as regards the presence of ground glassing, consolidation and pleural effusion. Results: 198 (67.1%) showed ground glassing and 36.9% (109 cases) had consolidation in their CT. These lesions were bilateral in 181 cases about 63.3% being single in in 71 cases (25.3 %). Pleural effusion was found in 202 cases (68.7%). Significant correlation was found between CRP, s. ferritin and d-dimer with presence of consolidation. Significant decreased neutrophil count and decreased DD among positive in comparison with negative ground glassing. PCR results were available in only 144 out of 295 patients (48.8%). It was positive in 100 out of 144 patients (69.4%) and negative in 44 patients (30.6%). Highly significant relation between COVID-19 Reporting and Data System (CO-RADS) categories & PCR among all studied cases. Conclusion: During the second wave, the CT findings were similar to wave one with PCR proved COVID-19 cases more frequent with higher CO-RADS and RSNA categories

The Moderating Effect of Audit Quality on the Links Between Stock Market Segmentations, Surplus Free Cash Flow, and Income-increasing Discretionary Accruals

The objective of this paper is to examine the impacts of stock market segmentations (SMS) and surplus free cash flow (SFCF) on income-increasing discretionary accruals. The study also provides the initial evidence regarding the influence of audit quality (AQ) as a moderating variable on those relationships. A sample of non-financial firms was taken from the list of Amman Stock Exchange over the period 2013-2019. Using Huber-White’s sandwich estimator for pooled OLS regression, the current research presents empirical evidence harmonious with the prediction in all hypotheses. Further, the findings document that a Big 4 auditor weakens the SMS-DAC and SFCF-DAC associations, which suggests that the role of Big 4 audit firms is effective in mitigating management’s opportunistic behaviour. However, the reported results provide beneficial information to investors, regulators, external auditors, policymakers, shareholders, and other countries with similar institutional environment

SMART CITY SECURITY: FACE-BASED IMAGE RETRIEVAL MODEL USING GRAY LEVEL CO-OCCURRENCE MATRIX

Nowadays, a lot of images and documents are saved on data sets and cloud servers such as certificates, personal images, and passports. These images and documents are utilized in several applications to serve residents living in smart cities. Image similarity is considered as one of the applications of smart cities. The major challenges faced in the field of image management are searching and retrieving images. This is because searching based on image content requires a long time. In this paper, the researchers present a secure scheme to retrieve images in smart cities to identify wanted criminals by using the Gray Level Co-occurrence Matrix. The proposed scheme extracts only five features of the query image which are contrast, homogeneity, entropy, energy, and dissimilarity. This work consists of six phases which are registration, authentication, face detection, features extraction, image similarity, and image retrieval. The current study runs on a database of 810 images which was borrowed from face94 to measure the performance of image retrieval. The results of the experiment showed that the average precision is 97.6 and average recall is 6.3., Results of the current study have been relatively inspiring compared with the results of two previous studies

Jordanian Arabic Teachers’ Knowledge Level about Language Skills Assessment

هدفت الدراسة إلى الكشف عن مستوى معرفة معلمي اللغة العربية في الأردن بتقييم المهارات اللغوية (الاستماع، والتحدث، والقراءة، والكتابة)، وما إذا كان ذلك يختلف باختلاف متغيري المؤهل العلمي، وعدد سنوات الخبرة. ولتحقيق أهداف الدراسة، استخدم اختبار المعرفة بتقييم المهارات اللغوية، وزّع بالتساوي إلى أربعة اختبارات فرعية لمهارات: القراءة، والكتابة، والاستماع، والتحدث، تكونت عينة الدراسة من (205) من معلمي اللغة العربية ومعلماتها في المدارس التابعة لمديرية التربية والتعليم للواء بني كنانة في محافظة إربد. أظهرت نتائج الدراسة أن مستوى معرفة معلمي اللغة العربية بتقييم المهارات اللغوية متدن في الاختبار ككل، وفي المجالات جميعها؛ إذ جاءت المجالات حسب مستوى معرفتهم بتقييمها مرتبة كالآتي: القراءة، فالكتابة، فالتحدث، فالاستماع. وفي ضوء نتائج الدراسة، قدمت التوصيات اللازمة.The study aimed at investigating Jordanian Arabic teachers’ knowledge level about language skills assessment (listening, speaking, reading, and writing), and whether the level of their knowledge differs according to the variables of qualification, and years of experience. To achieve the aims of the study, the language assessment knowledge test was used, the test consisted of (60) true false items.   The sample of the study consisted of (205) Arabic teachers in the schools affiliated to Bani Kinana directorate of education in Irbid Governorate.The results of the study showed that the knowledge level of Arabic teachers' language skills assessment was low in the test as a whole and in each domains, where the order of skills according to the level of their knowledge was as follows: reading, writing, speaking, listening. The results also showed that there were no statistical significant differences in the level of teachers' knowledge about language skills assessment according to the variables of qualification and years of experience

COVID-19 in a pregnant patient with beta-thalassemia major: A case report

Further studies are needed on this unique population to better manage them and increase their chances of normal pregnancy and fewer complications and more favorable outcomes

Comparison of Mycobacterium tuberculosis drug susceptibility using solid and liquid culture in Nigeria.

BACKGROUND: This study compares Mycobacterium tuberculosis culture isolation and drug sensitivity testing (DST) using solid (LJ) and liquid (BACTEC-MGIT-960) media in Nigeria. METHODS: This was a cross sectional survey of adults attending reference centres in Abuja, Ibadan and Nnewi with a new diagnosis of pulmonary tuberculosis (TB) or having failed the first-line TB treatment. Patients were requested to provide three sputum specimens for smear-microscopy and culture on LJ and BACTEC-MGIT-960. Positive cultures underwent DST for streptomycin, isoniazid, rifampicin and ethambutol. RESULTS: 527 specimens were cultured. 428 (81%) were positive with BACTEC-MGIT-960, 59 (11%) negative, 36 (7%) contaminated and 4 (1%) had non-tuberculosis mycobacteria (NTM). 411 (78%) LJ cultures were positive, 89 (17%) negative, 22 (4%) contaminated and 5 (1%) had NTM. The mean (SD) detection time was 11 (6) and 30 (11) days for BACTEC-MGIT-960 and LJ. DST patterns were compared in the 389 concordant positive BACTEC-MGIT-960 and LJ cultures. Rifampicin and isoniazid DST patterns were similar. Streptomycin resistance was detected more frequently with LJ than BACTEC-MGIT-960 and ethambutol resistance was detected more frequently with BACTEC-MGIT-960 than LJ, but differences were not statistically significant. MDR-TB was detected in 27 cases by LJ and 25 by BACTEC-MGIT-960 and using both methods detected 29 cases. CONCLUSIONS: There was a substantial degree of agreement between the two methods. However using the two in tandem increased the number of culture-positive patients and those with MDR-TB. The choice of culture method should depend on local availability, cost and test performance characteristics

TM NONLINEAR ELECTROMAGNETIC WAVES IN SEMICONDUCTOR SUPERLATICES WAVEGUIDING SYSTEMS

Considerable attention has been devoted to a nonlinear waves propagation in various wave-guide structure due to their applications in photonic-microwave devices . In this communication, the dispersion characteristics of transverse magnetic polarized waves nonlinear guided waves propagating in a multilayer semiconductor superlattices waveguide surrounded by one side by a nonlinear magnetic cover have been investigated theoretically. The two sublattice uniaxial antiferromagnetic crystal is considered as a nonlinear magnetic medium where the permeability is treated as a function of the magnetic field. Nummerical results are demonstrated for a waveguiding system containing some number of layers of superlattices. We hope that our present work could lead to several extensions and promising applications in future technology