Evaluation of FSW Process Parameters of Dissimilar Aluminium Alloys

Friction stir welding (FSW) is relatively a new welding technology applied to join weldable Aluminum alloys and non- weldable Aluminum alloys that are widely used in many industrial applications such as aerospace, marine, automotive, and other industrial applications. In present research, dissimilar AA2024-T3 and AA6061-T6 Aluminum alloys of 3mm thickness was butt joined by using friction stir welding. The experimental study to optimize the welding parameters on tensile strength and bending test was carried out by Taguchi’s L9 orthogonal array. Experiments have been employed based on four welding parameters, namely, the tool traverse speed, rotational speed, tilt angle of tool and tool geometry. ANOVA technique and signal to Noise ratio were used to determine the most significant parameter that affects the mechanical properties of the weldment. X-ray radiographic, microstructure, microhardness tests have been conducted to demonstrate that samples subjected to the optimum welding parameters gave good quality and no defects have been observed. Keywords: FSW, aluminium alloys, dissimilar alloys, Taguchi Techniques, ANOVA, S/N ratio

Trust and cultural factors impacting on information system compliance through the lens of Arab culture in a Saudi Arabian company

Previous studies explored some factors that impact on information security but research that presents a comprehensive understanding of managing information security through the lens of local Arab culture has been lacking. Hence this research investigates various cultural factors to enable local organizations to holistically adopt those factors to manage information security compliance in the Middle Eastern Arab region. This study used a quantitative research approach, and a web-based questionnaire was custom designed and administrated to a representative sample of 300 of which there were 247 usable responses. Following a series of pilot phases, the data was analysed using Structural Equation Modelling (SEM) with AMOS, and SPSS software. The sample was drawn from a total of 1500 local Arab employees within a Saudi Oil Company. An initial model linked the 6 factors that were latent in the literature. The initial model connected trust, workplace culture, leaders, western technology, employees’ alignment with information security. However, that model was found to be inadequate and following analysis of the pilot data from 3 pilot phases, a final parsimonious model showed 8 interconnections between 6 new emergent factors. That model contained belief, expectation, and trustworthiness of co-workers, workplace culture and supportive leadership, trust towards others, Western IT satisfaction, data privacy, and ISS compliance. Hence, this research makes a novel contribution by modelling the information security compliance in the lens of the local Arab region and leads the way for further research in the context of information security culture in the Arab region. This research was first to be conducted Information Security Management through the lens of Arab culture and opens-up many new avenues for future research in the context of Arab culture and Information Security Management

Evaluation of Liquid Loading in Gas Wells Using Machine Learning

The inevitable result that gas wells witness during their life production is the liquid loading problem. The liquids that come with gas block the production tubing if the gas velocity supplied by the reservoir pressure is not enough to carry them to surface. Researchers used different theories to solve the problem naming, droplet fallback theory, liquid film reversal theory, characteristic velocity, transient simulations, and others. While there is no definitive answer on what theory is the most valid or the one that performs the best in all cases. This paper comes to involve a different approach, a combination between physics-based modeling and statistical analysis of what is known as Machine Learning (ML). The authors used a refined ML algorithm named XGBoost (extreme gradient boosting) to develop a novel full procedure on how to diagnose the well with liquid loading issues and predict the critical gas velocity at which it starts to load if not loaded already. The novel procedure includes a combination of a classification problem where a well will be evaluated based on some completion and fluid properties (diameter, liquid density, gas density, liquid viscosity, gas viscosity, angle of inclination from horizontal (alpha), superficial liquid velocity, and the interfacial tension) as a “Liquid Loaded” or “Unloaded”. The second practice is to determine the critical gas velocity, and this is done by a regression method using the same inputs. Since the procedure is a data-driven approach, a considerable amount of data (247 well and lab measurements) collected from literatures has been used. Convenient ML technics have been applied from dividing the data to scaling, modeling and assessment. The results showed that a wellconstructed XGBoost model with an optimized hyperparameters is efficient in diagnosing the wells with the correct status and in predicting the onset of liquid loading by estimating the critical gas velocity. The assessment of the model was done relatively to existing correlations in literature. In the classification problem, the model showed a better performance with an F-1 score of 0.947 (correctly classified 46 cases from 50 used for testing). In contrast, the next best model was the one by Barnea with an F-1 score of 0.81 (correctly classified 37 from 50 cases). In the regression problem, the model showed an R2 of 0.959. In contrast, the second best model was the one by Shekhar with an R2 of 0.84. The results shown here prove that the model and the procedure developed give better results in diagnosing the well correctly if properly used by engineers

Differentiation of Adipose-Derived Mesenchymal Stem Cells into Neuron-Like Cells induced by using β-mercaptoethanol

 تم استخدام الخلايا الجذعية المشتقة من Adipose cells  كبديل لخلايا نخاع العظام في هذه الدراسة. الهدف: تم عزل الخلايا في المختبر، وتحديد هوية الخلايا الناتجة، وبعدها تحفيز تمايزها من خلايا جذعية الى خلايا عصبية من أجل إنتاج الخلايا العصبية والتي من شأنها أن تكون مفيدة في علاج إصابات الأعصاب. طرائق العمل: تم عزل الخلايا الجذعية المزنكيمية من الخلايا تحت الجلد لجذع الفئران المختبرية. بعدها تم تحفيز تمايز الخلايا الناتجة الى خلايا عصبية باستخدام مادة تحفيزية هي  β-mercaptoethanol . ولغرض اثبات تمايز الخلايا الناتجة تم استخدام نوعين من الماركرات لمرحلتين متتاليتين من مراحل انتاج الخلايا العصبية وهما nestin  وهو ماركر موجود في المراحل الاولية للانتاج ( أي الخلايا العصبية في المراحل الاولية للتمايز او غير الناضجة) و neurofilament light-chain وهو ماركر موجود في المرحلة المتقدمة (أي الخلايا العصبية المكتملة التمايز او الناضجة). النتائج: أظهرت نتائج الكيمياء المناعية ICC نجاح استخدام مادة الـ β-mercaptoethanol في إنتاج الخلايا العصبية. ويعزى ذلك إلى الزيادة التصاعدية والإفراط الكبير في التعبير عن بروتين nestin خلال فترات التعرض المختلفة لمادة التمايز العصبي. وبالمقارنة كان مستوى التعبير عن بروتين neurofilament light-chain أقل خلال فترات التعرض لمادة التمايز العصبي بالمقارنة مع الخلايا الجذعية  المزنكيمية قبل التمايز والتي استخدمت للمقارنة والتي أظهرت مستويات تعبير منخفضة جدا لكلا الماركرات. الاستنتاج: تشير نتائج هذه الدراسة إلى أن خلايا الـ Adipose  تمثل مصدراً جيداً لانتاج الخلايا العصبية ويمكن الحصول عليها بسهولة مقارنة مع خلايا نخاع العظام المستخدمة عادة في الانتاج.Background: Adipose derived-mesenchymal stem cells have been used as an alternative to bone marrow cells in this study. Objective: We investigated the in vitro isolation, identification, and differentiation of stem cells into neuron cells, in order to produce neuron cells via cell culture, which would be useful in nerve injury treatment. Method: Mouse adipose mesenchymal stem cells were dissected from the abdominal subcutaneous region. Neural differentiation was induced using β-mercaptoethanol. This study included two different neural stage markers, i.e. nestin and neurofilament light-chain, to detect immature and mature neurons, respectively. Results: The immunocytochemistry results showed that the use of β-mercaptoethanol resulted in the successful production of neuron cells. This was attributable to the increase and significant overexpression of the nestin protein during the early exposure period, which resulted in the expression of the highest levels of nestin. In comparison, the expression level of neurofilament light-chain protein also increased with time but less than nestin. Non-treated mesenchymal stem cells, considered as control showed very low expression for both markers. Conclusion: The results of this study indicate that adipose mesenchymal cells represent a good, easily obtainable source of bone marrow cells used to developing the differentiation process

Production and Purification of Laccase Enzyme by Klebsiella pneumoniae K7

Sixty-four isolate were klebsiella pneumoniae. Fourteen bacteria isolates “Kelbsiella species” were taken from soil and water hospital in the period between October to December 2018, those isolated were cultured on a blood agar to test their ability to hydrolytic due to formation the inhibition  zone . Twenty one isolates of K. pneumoniae were selected to be cultured in mineral salt agar for testing their efficiency to produce laccase enzyme .The efficient isolate was diagnosed depending on phenotypic, microscopic and biochemical tests to be Klebsiella pneumoniae K7. Laccases (benzenediol: oxygen oxidoreductases; EC: 1.10.3.2) are  subfamily of multicopper oxidases (MCOs) from Klebsiella pneumoniae K7 has been partially characterized by many researchers. In this paper, we purified laccase to homogeneity from Klebsiella pneumoniae K7  with about 10.82 ; 5.12 purification fold and a 34.14; 21.46% recovery by ion-exchange and gel-filtration chromatographic respectively.  The molecular weight of the Laccase as determined by gel filtration chromatography using Sephacryl S-200 gel was 120 KDalton. Keywords: Laccases , Klebsiella pneumoniae, molecular weight, purification. DOI: 10.7176/CMR/10-5-03 Publication date:May 31st 202

Coronary artery bypass grafting in a patient with polycythaemia rubra vera - a rare indication with a spectrum of complication: a case report

Coronary artery bypass surgery for coronary artery thrombosis in patients with polycythaemia rubra vera has been rarely described. The main issue with such patients is their risk of both bleeding and thrombosis and as such the ideal postoperative management of such cases is unknown. Hereby, we describe a case of a 62-year-old man with polycythaemia rubra vera who underwent coronary artery bypass surgery. Although his initial postoperative course was complicated, his long-term outcome was good

In vitro isolation and expansion of neural stem cells NSCs

     الخلايا الجذعية العصبية (NSCs) هي خلايا مولدة لديها القدرة على التجديد الذاتي والقدرة على التمايز إلى خلايا عصبية نجمية astrocytes ، وخلايا عصبية قليلة التفرع  oligodendrocyte، و خلايا عصبية neuron . في هذه الدراسة تم عزل الخلايا الجذعية في المختبر ، وتنميتها في المختبر ، وتحديد هويتها ، ومن ثم انتاج الخلايا الجذعية العصبية وحفظها بالنيتروجين السائل كمصدر خلايا ناجح لاستخدامها لاحقا في التجارب العلاجية. تم استخدام نخاع عظم الفأر كمصدر للخلايا الجذعية العصبية في هذه الدراسة. أظهرت نتائج دراسة الشكل المظهري والكيمياء المناعية للخلايا المعزولة أنه يمكننا إنتاج الخلايا الجذعية العصبية NSCs بنجاح والحفاظ على تجديدها الذاتي وتشكيلها بنجاح في الغلاف العصبي ولتمريرات متعددة. تم الحفاظ على الشكل المظهري للخلايا الناتجة وتخزينها في النيتروجين السائل لتكون مصدرا جاهزا للاستخدام في التجارب كنموذج لعلاج الاضطرابات العصبية.   Neural stem cells (NSCs) are progenitor cells which have the ability to self‑renewal and potential for differentiating into neurons, oligodendrocytes, and astrocytes. The in vitro isolation, culturing, identification, cryopreservation were investigated to produce neural stem cells in culture as successful sources for further studies before using it for clinical trials. In this study, mouse bone marrow was the source of neural stem cells. The results of morphological study and immunocytochemistry of isolated cells showed that NSCs can be produced successfully and maintaining their self‑renewal and successfully forming neurosphere for multiple passages. The spheres preserved their morphology in culture and cryopreserved to be a ready source for use in experiments as a model for neurological disorders