High-Performance Elevator Traction Using Direct Torque Controlled Induction Motor Drive

Arafa, Osama Mohamed,Abdallah, Mohamed Elsayed,Aziz, Ghada Ahmed Abdel The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

This paper presents a detailed realization of direct torque controlled induction motor drive for elevator applications. The drive is controlled according to the well-known space vector modulated direct control scheme (SVM-DTC). As the elevator drives are usually equipped with speed sensors, flux estimation is carried out using a current model where two stator currents are measured and accurate instantaneous rotor speed measurement is used to overcome the need for measuring stator voltages. Speed profiling for a comfortable elevator ride and other supervisory control activities to provide smooth operation are also explained. The drive performance is examined and controllers' parameters are fine-tuned using MATLAB/SIMULINK. The blocks used for flux and torque estimation and control in the offline simulation are compiled for real-time using dSPACE Microlabox. The performance of the drive has been verified experimentally. The results show good performance under transient and steady state conditions.

High-Performance Elevator Traction Using Direct Torque Controlled Induction Motor Drive

Osama Mohamed Arafa,Mohamed Elsayed Abdallah,Ghada Ahmed Abdel Aziz 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

This paper presents a detailed realization of direct torque controlled induction motor drive for elevator applications. The drive is controlled according to the well-known space vector modulated direct control scheme (SVM-DTC). As the elevator drives are usually equipped with speed sensors, flux estimation is carried out using a current model where two stator currents are measured and accurate instantaneous rotor speed measurement is used to overcome the need for measuring stator voltages. Speed profiling for a comfortable elevator ride and other supervisory control activities to provide smooth operation are also explained. The drive performance is examined and controllers’ parameters are fine-tuned using MATLAB/SIMULINK. The blocks used for flux and torque estimation and control in the offline simulation are compiled for real-time using dSPACE Microlabox. The performance of the drive has been verified experimentally. The results show good performance under transient and steady state conditions.

Lumbar Transpedicular Implant Failure: A Clinical and Surgical Challenge and Its Radiological Assessment

Mohamed M. Mohi Eldin,Abdel Mohsen Arafa Ali 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.3

multicenter, controlled case study review of a big scale of pedicle-screw procedures from January 2000 to June 2010. The outcomes were compared to those with no implant failure. Purpose: The purpose of this study was to review retrospectively the outcome of 100 patients with implant failure in comparison to 100 control-patients, and to study the causes of failure and its prevention. Overview of Literature: Transpedicular fixation is associated with risks of hardware failure, such as screw/rod breakage and/or loosening at the screw-rod interface and difficulties in the system assembly, which remain a significant clinical problem. Removal or revision of the spinal hardware is often required. Methods: Two hundred patients (88 women, 112 men) were divided into 2 major groups, with 100 patients in group I (implant failure group G1) and 100 patients in group II (successful fusion, control group G2). We subdivided the study groups into two subgroups: subgroup a (single-level instrumented group) and subgroup b (multilevel instrumented group). The implant status was assessed based on intraoperative and follow-up radiographs. Results: Implant failure in general was present in 36% in G1a, and in 64% in G1b, and types of implant failure included screw fracture (34%), rod fracture (24%), rod loosening (22%), screw loosening (16%), and failure of both rod and screw (4%). Most of the failures (90%) occurred within 6 months after surgery, with no reported cases 1 year postoperatively. Conclusions: We tried to address the problem and study the causes of failure, and proposed solutions for its prevention.

Poster Session : PS 0360 ; Epidemiology and Public Health : Relation between Pack-Years Tobacco Smoking and Overt Hepatic Encephalopathy in Known Hepatic Patients

( Mohammed Abd Elfattah Darwesh ),( Wessam Arafa ),( Omneya Ali ),( Abdallah Bastawesy ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Hepatic encephalopathy is a syndrome observed in patients with liver cirrhosis and the development of hepatic encephalopathy is explained, to some extent, by the effect of neurotoxic substances, which occurs in the setting of cirrhosis and portal hypertension. Few studies have been conducted to evaluate the risk of smoking in developing hepatic encephalopathy. Methods: This was a cross sectional study of 93 (males=64, females=29) previously diagnosed hepatic patients recently admitted in Alexandria university Main hospital using pretested questionnaire tool. Chi square test of independence and Pearson`s correlation coeffi cient were used to analyze our data. Cox proportional models, stratifi ed by gender, were used to estimate hazard ratios. Results: We have found that 78% of hepatic patients who are smoker have a previous history of overt hepatic encephalopathy with evidence of relation between smoking status and developing hepatic coma (P <. 0001) and the hepatic patients who are smokers had a higher risk of developing hepatic comas than who never smoke (HR 2. 521, 95% CI 1. 197-5. 310) and the risk is found to be higher in females (HR 7. 554, 95% CI 1. 370-41. 652). Smoking pack-years were also associated with increasing the risk of developing hepatic comas (HR 1. 000, 95% CI 0. 993-1. 007). Conclusions: Our fi ndings suggest an evidence of relation between tobacco smoking and development of hepatic comas in known hepatic patients. So, we strongly recommend educating hepatic patients to quit smoking especially female hepatic patients.

Two-Stages Sliding Fourier Transform for High Performance Phase Angle and Frequency Tracking

Osama Mohammed Arafa 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.5

Sliding discrete Fourier transform (SDFT) gives excellent performance at nominal frequency operation. However, at off - nominal frequency, it generates errors in both magnitude and phase angle due to spectral leakage. Moreover, its harmonic rejection ability is greatly impaired in this case. This paper introduces a method to apply sliding Fourier transform under off -nominal frequency at fi xed sampling rate while fi xing the defects associated with it off -nominal frequency operation. This method involves the use of two stages sliding Fourier transform (SFT). A fi xed window-width SFT in the fi rst stage is used to drive the variable window-width SFT in the second stage. The proposed technique (SFT–SFT) is tested in real time on dSPACE MicroLabBox using pre-generated voltage vectors to simulate the most inconvenient grid conditions. The testing scenarios proved its superior performance compared to the decoupled stationary reference frame PLL method.

Histological and Physiological Studies of the Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Bleomycin Induced Lung Fibrosis in Adult Albino Rats

Zakaria Dina Mohamed,Zahran Noha Mahmoud,Arafa Samia Abdel Aziz,Mehanna Radwa Ali,Abdel-Moneim Rehab Ahmed 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.1

Background: Lung fibrosis is considered as an end stage for many lung diseases including lung inflammatory disease, autoimmune diseases and malignancy. There are limited therapeutic options with bad prognostic outcome. The aim of this study was to explore the effect of mesenchymal stem cells (MSCs) derived from bone marrow on Bleomycin (BLM) induced lung fibrosis in albino rats. Methods: 30 adult female albino rats were distributed randomly into 4 groups; negative control group, Bleomycin induced lung fibrosis group, lung fibrosis treated with bone marrow-MSCs (BM-MSCs) and lung fibrosis treated with cell free media. Lung fibrosis was induced with a single dose of intratracheal instillation of BLM. BM-MSCs or cell free media were injected intravenously 28 days after induction and rats were sacrificed after another 28 days for assessment. Minute respiratory volume (MRV), forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) were recorded using spirometer (Power lab data acquisition system). Histological assessment was performed by light microscopic examination of H&E, and Masson’s trichrome stained sections and was further supported by morphometric studies. In addition, electron microscopic examination to assess ultra-structural changes was done. Confocal Laser microscopy and PCR were used as tools to ensure MSCs homing in the lung. Results: Induction of lung fibrosis was confirmed by histological examination, which revealed disorganized lung architecture, thickened inter-alveolar septa due excessive collagen deposition together with inflammatory cellular infiltration. Moreover, pneumocytes depicted variable degenerative changes. Reduction in MRV, FVC and FEV1 were recorded. BM-MSCs treatment showed marked structural improvement with minimal cellular infiltration and collagen deposition and hence restored lung architecture, together with lung functions. Conclusion: MSCs are promising potential therapy for lung fibrosis that could restore the normal structure and function of BLM induced lung fibrosis. Background: Lung fibrosis is considered as an end stage for many lung diseases including lung inflammatory disease, autoimmune diseases and malignancy. There are limited therapeutic options with bad prognostic outcome. The aim of this study was to explore the effect of mesenchymal stem cells (MSCs) derived from bone marrow on Bleomycin (BLM) induced lung fibrosis in albino rats. Methods: 30 adult female albino rats were distributed randomly into 4 groups; negative control group, Bleomycin induced lung fibrosis group, lung fibrosis treated with bone marrow-MSCs (BM-MSCs) and lung fibrosis treated with cell free media. Lung fibrosis was induced with a single dose of intratracheal instillation of BLM. BM-MSCs or cell free media were injected intravenously 28 days after induction and rats were sacrificed after another 28 days for assessment. Minute respiratory volume (MRV), forced vital capacity (FVC) and forced expiratory volume 1 (FEV1) were recorded using spirometer (Power lab data acquisition system). Histological assessment was performed by light microscopic examination of H&E, and Masson’s trichrome stained sections and was further supported by morphometric studies. In addition, electron microscopic examination to assess ultra-structural changes was done. Confocal Laser microscopy and PCR were used as tools to ensure MSCs homing in the lung. Results: Induction of lung fibrosis was confirmed by histological examination, which revealed disorganized lung architecture, thickened inter-alveolar septa due excessive collagen deposition together with inflammatory cellular infiltration. Moreover, pneumocytes depicted variable degenerative changes. Reduction in MRV, FVC and FEV1 were recorded. BM-MSCs treatment showed marked structural improvement with minimal cellular infiltration and collagen deposition and hence restored lung architecture, together with lung functions. Conclusion: MSCs are promising potential therapy for lung fibrosis that could restore the normal structure and function of BLM induced lung fibrosis.

Potential Role for a Panel of Immunohistochemical Markers in the Management of Endometrial Carcinoma

Amany Salama,Mohammad Arafa,Eman ElZahaf,Abdelhadi Mohamed Shebl,Azmy Abd El-Hameed Awad,Sylvia A. Ashamallah,Reda Hemida,Anas Gamal,Abd AlRahman Foda,Khaled Zalata,El-Said M. Abdel-Hady 대한병리학회 2019 Journal of Pathology and Translational Medicine Vol.53 No.3

Background: In order to improve the efficacy of endometrial carcinoma (EC) treatment, identifying prognostic factors for high risk patients is a high research priority. This study aimed to assess the relationships among the expression of estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptor 2 (HER2), Ki-67, and the different histopathological prognostic parameters in EC and to assess the value of these in the management of EC. Methods: We examined 109 cases of EC. Immunohistochemistry for ER, PR, HER2, and Ki-67 were evaluated in relation to age, tumor size, International Federation of Gynecology and Obstetrics (FIGO) stage and grade, depth of infiltration, cervical and ovarian involvement, lymphovascular space invasion (LVSI), and lymph node (LN) metastasis. Results: The mean age of patients in this study was 59.8 ± 8.2 years. Low ER and PR expression scores and high Ki-67 expression showed highly significant associations with non-endometrioid histology (p = .007, p < .001, and p < .001, respectively) and poor differentiation (p = .007, p < .001, and p <. 001, respectively). Low PR score showed a significant association with advanced stage (p = .009). Low ER score was highly associated with LVSI (p = .006), and low PR scores were associated significantly with LN metastasis (p = .026). HER2 expression was significantly related to advanced stages (p = .04), increased depth of infiltration (p = .02), LVSI (p = .017), ovarian involvement (p = .038), and LN metastasis (p = .038). There was a close relationship between HER2 expression and uterine cervical involvement (p = .009). Higher Ki-67 values were associated with LN involvement (p = .012). Conclusions: The over-expression of HER2 and Ki-67 and low expression of ER and PR indicate a more malignant EC behavior. An immunohistochemical panel for the identification of high risk tumors can contribute significantly to prognostic assessments.

Sperm DNA Fragmentation: A Critical Assessment of Clinical Practice Guidelines

Agarwal Ashok,Farkouh Ala'a,Parekh Neel,Zini Armand,Arafa Mohamed,Kandil Hussein,Tadros Nick,Busetto Gian Maria,Ambar Rafael,Parekattil Sijo,Boitrelle Florence,Sallam Hassan N.,Jindal Sunil,Ko Edmund 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.1

Sperm DNA fragmentation (SDF) is implicated in male infertility and adverse reproductive outcomes. With the publication of many studies regarding the etiologies and contributors to SDF, as well as the effects of SDF, guidelines are necessary to aid clinicians in the application of SDF for male fertility evaluation. Two recent clinical practice guidelines were published by Agarwal et al and Esteves et al. In this article, we have evaluated and compared both guidelines. We have found fairly similar recommendations between the two guidelines and have also highlighted the differences between them. Finally, we have summarized and combined the best practice recommendations from both guidelines.

Utility of Antioxidants in the Treatment of Male Infertility: Clinical Guidelines Based on a Systematic Review and Analysis of Evidence

Agarwal Ashok,Leisegang Kristian,Majzoub Ahmad,Henkel Ralf,Finelli Renata,Panner Selvam Manesh Kumar,Tadros Nicholas,Parekh Neel,Ko Edmund Y.,Cho Chak-Lam,Arafa Mohamed,Alves Marco G.,Oliveira Pedro F 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.2

It is widely accepted that oxidative stress plays an important role in the pathophysiology of male infertility and that antioxidants could have a significant role in the treatment of male infertility. The main objectives of this study are: 1) to systematically review the current evidence for the utility of antioxidants in the treatment of male infertility; and 2) propose evidence-based clinical guidelines for the use of antioxidants in the treatment of male infertility. A systematic review of the available clinical evidence was performed, with articles published on Scopus being manually screened. Data extracted included the type of antioxidant used, the clinical conditions under investigation, the evaluation of semen parameters and reproductive outcomes. The adherence to the Cambridge Quality Checklist, Cochrane Risk of Bias for randomized controlled trials (RCTs), CONSORT guidelines and JADAD score were analyzed for each included study. Further, we provided a Strength Weakness Opportunity Threat (SWOT) analysis to analyze the current and future value of antioxidants in male infertility. Of the 1,978 articles identified, 97 articles were included in the study. Of these, 52 (53.6%) were uncontrolled (open label), 12 (12.4%) unblinded RCTs, and 33 (34.0%) blinded RCTs, whereas 44 (45.4%) articles tested individual antioxidants, 31 (32.0%) a combination of several products in variable dosages, and 22 (22.6%) registered antioxidant products. Based on the published evidence, we 1) critically examined the necessity of additional double-blind, randomized, placebo-controlled trials, and 2) proposed updated evidence-based clinical guidelines for antioxidant therapy in male infertility. The current systematic review on antioxidants and male infertility clearly shows that antioxidant supplementation improves semen parameters. In addition, it provides the indications for antioxidant treatment in specific clinical conditions, including varicocele, unexplained and idiopathic male infertility, as well as in cases of altered semen quality.