African vulture optimizer algorithm based vector control induction motor drive system

This study describes a new optimization approach for three-phase induction motor speed drive to minimize the integral square error for speed controller and improve the dynamic speed performance. The new proposed algorithm, African vulture optimizer algorithm (AVOA) optimizes internal controller parameters of a fuzzy like proportional differential (PD) speed controller. The AVOA is notable for its ease of implementation, minimal number of design parameters, high convergence speed, and low computing burden. This study compares fuzzy-like PD speed controllers optimized with AVOA to adaptive fuzzy logic speed regulators, fuzzy-like PD optimized with genetic algorithm (GA), and proportional integral (PI) speed regulators optimized with AVOA to provide speed control for an induction motor drive system. The drive system is simulated using MATLAB/Simulink and laboratory prototype is implemented using DSP-DS1104 board. The results demonstrate that the suggested fuzzy-like PD speed controller optimized with AVOA, with a speed steady state error performance of 0.5% compared to the adaptive fuzzy logic speed regulator’s 0.7%, is the optimum alternative for speed controller. The results clarify the effectiveness of the controllers based on fuzzy like PD speed controller optimized with AVOA for each performance index as it provides lower overshoot, lowers rising time, and high dynamic response

Non-invasive index of liver fibrosis induced by alcohol, thioacetamide and schistosomal infection in mice

<p>Abstract</p> <p>Background</p> <p>Non invasive approaches will likely be increasing utilized to assess liver fibrosis. This work provides a new non invasive index to predict liver fibrosis induced in mice.</p> <p>Methods</p> <p>Fibrosis was generated by thioacetamide (TAA), chronic intake of ethanol, or infection with <it>S. mansoni </it>in 240 mice. Both progression and regression of fibrosis (after treatment with silymarin and/or praziquantel) were monitored. The following methods were employed: (i) The METAVIR system was utilized to grade and stage liver inflammation and fibosis; (ii) Determination of hepatic hydroxyproline and collagen; and (iii) Derivation of a new hepatic fibrosis index from the induced changes, and its prospective validation in a group of 70 mice.</p> <p>Results</p> <p>The index is composed of 4 serum variable including total proteins, γ-GT, bilirubin and reduced glutathione (GSH), measured in diseased, treated and normal mice. These parameters were highly correlated with both the histological stage and the grade. They were combined in a logarithmic formula, which non-invasively scores the severity of liver fibrosis through a range (0 to 2), starting with healthy liver (corresponding to stage 0) to advanced fibrosis (corresponding stage 3).Receiver operating characteristic curves (ROC) for the accuracy of the index to predict the histological stages demonstrated that the areas under the curve (AUC) were 0.954, 0.979 and 0.99 for index values corresponding to histological stages 1, 2 and 3, respectively. Also, the index was correlated with stage and grade, (0.947 and 0.859, respectively). The cut off values that cover the range between stages 0-1, 1-2 and 2-3 are 0.4, 1.12 and 1.79, respectively. The results in the validation group confirmed the accuracy of the test. The AUROC was 0.869 and there was good correlation with the stage of fibrosis and grade of inflammation.</p> <p>Conclusion</p> <p>The index fulfils the basic criteria of non-invasive marker of liver fibrosis since it is liver-specific, easy to implement, reliable, and inexpensive. It proved to be accurate in discriminating precirrhotic stages.</p

Challenges in Learning to Speak Arabic

This paper describes a study to investigate the challenges and obstacles to speaking Arabic faced by good and poor Malay speakers of Arabic. The study used individual and focus group interviews with 14 participants to elicit data. The findings revealed 2 types of obstacles, namely, internal and external obstacles. Internal obstacles refer to the limitations that come from the learners’ own selves, knowledge and skills; while external obstacles refer to the constraints that originate from the outside, such as the lack of a supportive environment and sufficient opportunity to speak Arabic. Both good and poor Malay speakers of Arabic felt hampered more by the internal problems than by the external problems. However, it was noted that the good speakers faced more language-related problems than other internal issues, while the poor speakers   revealed more internal shortcomings such as lack of confidence and self-esteem. Keywords: Arabic language, language learning strategy, problems in learning speaking skills, speaking skills

Detection of Cancer Stem Cells in Colorectal Cancer: Histopathological and Immunohistochemical Study

BACKGROUND: Growing evidence supports the notion that the onset of tumorigenesis could occur through cancer stem cells (CSCs). These tumour cells show low proliferative rates, high self-renewal capacity, propensity to differentiate into active proliferating tumour cells &amp; resistance to chemoradiotherapy thus, possibly causing local recurrences &amp; metastasis formation. CD44 has been used as a marker to isolate CSCs from colorectal carcinoma (CRC).AIM: To investigate the immunohistochemical expression of cancer stem cells marker (CD44) in CRC and correlate its expression with the clinicopathological aspects, TNM staging and modified Dukes’ classification.MATERIALS AND METHODS: Tumour biopsies from colectomy specimens of 60 patients with CRC were stained with hematoxylin-eosin for histological evaluation then immunostained with monoclonal antibodies against CD44 which was detected in term of negative or positive expression.RESULTS: CD44 was demonstrated in 58.3% (35/60) of cases and showed statistically significant correlation with tumour site and histological type (p-value &lt; 0.05). However, CD44 showed statistically insignificant inverse correlation with tumour invasiveness (T), lymph node status (N), grade, TNM stage grouping and modified Dukes’ classification, while it was directly correlated with distant metastasis (M) (p-value &gt; 0.05). Chi-square /Fisher exact test proportion independence and the p-value are set significant at 0.05 level.CONCLUSION: the CD44 rate of expression is higher in the colon than rectum and in adenocarcinoma than mucinous and undifferentiated carcinoma. CD44 showed statistically insignificant relation with T, N, M, grade, TNM stage grouping and modified Dukes’ classification

Enhancing the Fault Ride-through Capability of a DFIG-WECS Using a High-Temperature Superconducting Coil

With the increase in doubly fed induction generator-based wind energy conversion systems (DFIG-WECS) worldwide, improving the fault ride-through (FRT) capability of the entire system has been given much attention. Enhancement of the FRT capability of a DFIG-WECS is conventionally realized by employing a flexible AC transmission system device with a proper control system. This paper presents a non-conventional method for the improvement of the FRT of DFIG-WECS, using a high-temperature superconducting coil interfaced with the DC-link of the rotor and stator side converters through a DC-chopper. A fractional-order proportional-integral (FOPI) controller is utilized to regulate the DC-chopper duty cycle in order to properly manage the power flow between the DC-link and the coil. Two optimization techniques, Harmony Search and Grey Wolf Optimizer, are employed to determine the optimum size of the superconducting coil along with the optimum parameters of the FOPI controller. The effectiveness of the two proposed optimization techniques is highlighted through comparing their performance with the well-known particle swarm optimization technique

Solar Hydrogen Variable Speed Control of Induction Motor Based on Chaotic Billiards Optimization Technique

This paper introduces a brand-new, inspired optimization algorithm (the chaotic billiards optimization (C-BO) approach) to effectively develop the optimal parameters for fuzzy PID techniques to enhance the dynamic response of the solar&ndash;hydrogen drive of an induction motor. This study compares fuzzy-PID-based C-BO regulators to fuzzy PID regulators based on particle swarm optimization (PSO) and PI-based PSO regulators to provide speed control in solar&ndash;hydrogen, induction-motor drive systems. The model is implemented to simulate the production and storage of hydrogen while powering an induction-motor drive which provides a great solution for the renewable energy storage problem in the case of solar pumping systems. MATLAB/Simulink 2021a is used to simulate and analyze the entire operation. The laboratory prototype is implemented in real time using a DSP-DS1104 board. Based on the simulation and experimental results, the proposed fuzzy-PID-based C-BO has reduced speed peak overshoot by 45.3% when compared to a fuzzy PID based PSO speed regulator and by 68.13% when compared to a PI-based PSO speed controller in the case of a large-scale motor. Additionally, the proposed speed regulator has a 6.1% faster speed rising time than a fuzzy-PID-based PSO and a 9.5% faster speed rising time than a PI&ndash;PSO speed controller. It has an excellent dynamic responsiveness value when compared to the other speed regulators

A case of infantile osteopetrosis: The radioclinical features with literature update

Background: Osteopetrosis is a rare hereditary metabolic bone disorder characterized by generalized skeletal sclerosis caused by a defect in bone resorption and remodelling. Infantile autosomal recessive osteopetrosis is one of three subtypes of osteopetrosis and the most severe form. The correct and early diagnosis of infantile osteopetrosis is important for management of complications and for future genetic counselling. Diagnosis is largely based on clinical and radiographic evaluation, confirmed by gene testing where applicable. Methods: Therefore, in this case study the classical clinical and radiological signs of a boy with infantile osteopetrosis will be presented with a comprehensive literature update. The differentiating signs from other causes of hereditary osteosclerosing dysplasias are discussed. Results: This case study and review of available literature show that there tends to be a highly unique clinical and skeletal radiographic pattern of affection in infantile osteopetrosis. Conclusion: Although tremendous advances have been made in the elucidation of the genetic defect of osteopetrosis over the past years, the role of accurate clinical and radiological assessment remains an important contributor to the diagnosis of infantile osteopetrosis

Experimental Validation of Second-Order Adaptive Fuzzy Logic Controller for Grid-Connected DFIG Wind Power Plant

This paper introduces a second-order adaptive fuzzy logic controller (SO-AFLC) to enhance the characteristics of a doubly fed induction generator (DFIG) inside a grid-tied wind power plant (WPP). SO-AFLCs were utilized to maximize the output of the DFIG wind power plant (WPP) and improve dynamic responsiveness with extremely low mean square error. When comparing the mean square error of SO-AFLC with proportional-integral controllers (PI) and adaptive fuzzy logic controllers (AFLC), the reductions are 87.38&#x0025; and 40.39&#x0025;, respectively. This controller prevents overshoots and oscillations. DFIG wind power plant is modeled and simulated using Matlab/Simulink package. Under the unit step wind speed profile, SO-AFLC improved the steady-state error in the Cp waveform by 63.25&#x0025; compared with the PI controller and 13.12&#x0025; compared with AFLC. DSpace1104 is used to conduct an experimental investigation to validate the simulation results. In addition, realistic data from the wind farm at RAS Ghareb in the Gulf of Suez, Egypt, are used in this study to achieve more realistic results. Compared to those obtained with PI and AFLC, the results obtained using SO-AFLCs showed fast time response, high convergence rate, reduced peak overshoot, less undershoot, and low steady-state error in terms of power coefficient of the turbine, DC link voltage control, and rotor speed tracking. In addition, a wind turbine performance index based on gross system integral absolute error (IAE) is provided. This index is used to illustrate the SO-AFLC methodology&#x2019;s viability compared to AFLC and PI under the same wind turbine conditions

Detoxification of Patulin by Kombucha tea culture

<p>Kombucha is a refreshing beverage, obtained by fermenting sugared tea with a symbiotic culture of acetic acid bacteria and yeast, consumed for its positive effects on human health. In this study, the potential of kombucha supernatant for reduction of patulin (PAT) of three toxigenic fungal strains (<i>Penicillium expansum</i> LC015096, <i>Talaromyces purpureogenus</i> LC015095, and <i>Acremonium implicatum</i> LC015097) in liquid medium and apple fruit was investigated. In liquid medium, kombucha up to 10% (v/v) significantly inhibited PAT production of <i>P. expansum</i> by 77.2% and that of <i>T. purpureogenus</i> and <i>A. implicatum</i> by 100%. In apple fruit, inhibition percent of PAT accumulation by the respective fungal strains was 49.8%, 100%, and 53%. In aqueous solution, kombucha cells showed a relative greater PAT uptake capacity than <i>Sacchromyces cerevisiae</i>. The maximum PAT uptake (64.67% and 60.69%) by viable and heat-treated kombucha cells was achieved at pH 3.0 throughout 48 h incubation, respectively.</p

Teacher Efficacy and Commitment in Teaching Arabic: a Correlational Study

The current study explores the validity and reliability of the instrument used in assessing teachers' efficacy in teaching Arabic and also their commitment to teaching. The study also examined Arabic teaching efficacy in relation to teacher commitment. The study involved 252 teachers out of 487 teachers from 57 National Religious Secondary Schools throughout Malaysia. A structural equation modeling with AMOS was employed to investigate the effects of the hypotheses model. Confirmatory factor analysis supported the adequacy of the constructs of teacher efficacy and teacher commitment and found that the two constructs were multidimensional constructs with four underlying dimensions respectively. The findings also showed that teacher efficacy influences teacher commitment. Several essential theoretical implications for developing and enhancing teachers in the Malaysian Secondary Arabic education context have arisen from the current study