Search

Predictive maintenance to avoid fatigue and failure enhances the reliability of mechanics, herewith, this paper explores vibrational time-domain data in advancing fault diagnosis of predictive maintenance. This study leveraged a belt-drive system with the properties: operating rotational speeds of 500–2000 RPM, belt pretensions at 70 and 150 N, and three operational cases of healthy, faulty and unbalanced, which leads to 12 studied cases. In this analysis, two one-axis piezoelectric accelerometers were utilized to capture vibration signals near the driver and pulley. Five advanced statistics were calculated during signal processing, namely Variance, Mean Absolute Deviation (MAD), Zero Crossing Rate (ZCR), Autocorrelation Coefficient, and the signal's Energy. The Taguchi method was used to test the five selected features on the basis of Signal-to-Noise (S/N) ratio. For classifications, an expert system was used based on artificial intelligence where a Random Forest (RF) model was trained on untraditional parameters for optimizing the accuracy. The resulted 0.990 and 0.999, accuracy and AUC, demonstrate the RF model's high dependability. Evidently, the methodology highlights the features potential when progressed into expert systems, which advances predictive maintenance strategies for belt-drive systems.

This review was focused on global data analysis and risk factors associated with morbidity and mortality of coronavirus disease 2019 from different countries, including Bangladesh, Brazil, China, Central Eastern Europe, Egypt, India, Iran, Pakistan, and South Asia, Africa, Turkey and UAE. Male showed higher confirmed and death cases compared to females in most of the countries. In addition, the case fatality ratio (CFR) for males was higher than for females. This gender variation in COVID-19 cases may be due to males cultural activities, but similar variations in the number of COVID-19 affected males and females globally. Variations in the immune system can illustrate this divergent risk comparatively higher in males than females. The female immune system may have an edge to detect pathogens slightly earlier. In addition, women show comparatively higher innate and adaptive immune responses than men, which might be explained by the high density of immune-related genes in the X chromosome. Furthermore, SARS-CoV-2 viruses use angiotensin-converting enzyme 2 (ACE2) to enter the host cell, and men contain higher ACE2 than females. Therefore, males may be more vulnerable to COVID-19 than females. In addition, smoking habit also makes men susceptible to COVID-19. Considering the age-wise distribution, children and older adults were less infected than other age groups and the death rate. On the contrary, more death in the older group may be associated with less immune system function. In addition, most of these group have comorbidities like diabetes, high pressure, low lungs and kidney function, and other chronic diseases. Due to the substantial economic losses and the numerous infected people and deaths, research examining the features of the COVID-19 epidemic is essential to gain insight into mitigating its impact in the future and preparedness for any future epidemics.

The aim of this paper is to investigate some types of stability such as generalized Hyers-Ulam- Rassias stability(G-H-U-R-stabile) and the relation with Hyers-Ulam(H-U-stabile) stable and Hyers-Ulam-Rassias stable (H-U-R-stabile) and generalized Hyers-Ulam stable (G-H-U- stable) to obtain which one guarantee to satisfy stability of equations included a nonlinear function some of them contains a delay time of solution and the other contain a vector of different order of derivatives for the solution to n-time and vector of fractional order of integrals with different fractional orders and that was the for using a claculse of fractional calculus to satisfies the issue of this techniques. Moreover, the nonlocal initial values for the proposal equation of nonlinear impulsive higher order differential – fractional integral delay time equations which are adding more interesting for nonlinear analytic object of nonlinear higher order integro – fractional order impulsive classes, and the impulsive difference of the equation has some necessary conditions to prove the results of solution to be stable with certain type has related with other types. The necessary and sufficient conditions which assumed on this nonlinear higher order integro-differential impulsive equation have been achieved the stability with interesting certain estimates obtain through the proving technique. Also the uniqueness of solution has been studied with same conditions was presented for stability and used for that issue a contraction fixed point theorem.

As the demand for energy and raw material is increasing everyday, so the challenge of finding sustainable and environment friendly alternatives are becoming very crucial and challenging for the textile industry. Sustainability is one of the most required characteristics in textile production and consumption. As a result, regenerated cellulose fibers have become very popular for their identical properties to cotton, conforming to the sustainability goals of this sector. Production of regenerated cellulose fiber known as Ecocell the trend of sustainability is getting promoted. The aim of this study is to evaluate the performance and dyeing properties of Ecocell in woven fabrics. In order to evaluate the viability, six different fabrics with different construction was weaved and dyed and subjected to several testing. The results indicate that the successful development of Ecocell can be a sustainable and eco-friendly replacement to the imported fibers. By enhancing our country's self-sufficiency in regenerated cellulose fiber production, the textile industry is taking a crucial step towards greater eco-consciousness and sustainability. This study not only contributes to the academic understanding of regenerated cellulose fibers but also holds practical implications for the industry's green transformation.

SMAs can switch from one crystallographic structure to another in response to temperature or stress stimuli. When SMAs are exposed to mechanical cyclic stress, they can absorb and discharge mechanical energy by experiencing a reversible hysteretic shape change. SMAs are widely used for sensing, actuation, impact absorption, and vibration damping. This work studied the effect of CeO2 addition on the transformation temperature and wear resistance of Cu-Al-Ni SMAs. WhereCeO2 was added at different percent’s 0.5, 1, and 3 wt% to the base alloy, followed by casting and homogenization at 900oC. Some tests were carried out: Differential scanning calorimeter, Optical Microscope, Scanning Electron microscopy, Energy dispersion spectrometer, X-Ray Diffraction, and Wear and Hardness tests. OM and SEM tests reveal that both phases of martensite β and γ are found. Also, the additions of CeO2 show a visible effect on phase formation and transformation temperatures. It was observed that increasing of CeO2 particles in Cu-based SMAs owing to improve interfacial bonding between matrix and reinforcement and also observed that the variants become thicker with increasing in percent. Additions of different percentages of cerium oxide increase the hardness of Cu-Al-Ni SMAs. Due to the addition of CeO2 particles, the sample's wear rate decreases compared to pure SMAs.

يهدف هذا البحث عبر فصولهِ إلى اختبار علاقة تأثير الشفافية التنظيمية كمتغير مستقل في الرقابة الإدارية كمتغير مستجيب في هيئة النزاهة الاتحادية أحد الهيئات الرقابية والتحقيقية المهمة في العراق، اذ يتجسد البحث في تشخيص طبيعة هذه العلاقة والتعرف على دور كل منهما، وتم طرح المشكلة البحث الرئيسية (هل استطاعت هيئة النزاهة من استثمار شفافيتها في تحسين رقابتها الادارية؟)، وللإجابة على هذا السؤال تم طرح فرضيتين رئيستين للبحث تحمل كل منها أبعادها، فالفرضية الأولى توجد علاقة ارتباط ذات دلالة معنوية بين الشفافية التنظيمية والرقابة الادارية في هيئة النزاهة، أما الفرضية الثانية يوجد تأثير ذات دلالة معنوية للشفافية التنظيمية في الرقابة الادارية بأبعادها في هيئة النزاهة، وكانت الاجابة عن هذه الفرضيات بوجود علاقة ارتباط ذات دلالة معنوية لكل من الفرضيتين، واستناداً إلى ملاءمة موضوع الدراسة في المؤسسات العامة ذات التوجه الإشرافي، وقيمة المنظمة المدروسة بالنسبة للمجتمع، فقد تم استخدام الأسلوب التحليلي الوصفي في إتمام البحث، وتضمن البحث عينة من قيادات الهيئة، وجمعت البيانات من (83) مستجيبا يمثلون عينة البحث من أصل (100) يمثلون مجتمع البحث، والمتمثل (بالمديرين العامين، معاونو المديرين العامين، رؤساء الأقسام، مسؤولي الشعب) اعتمادا على الاستبانة التي تضمنت (32) فقرة، لقد جمعهم باستخدام المقابلات الشخصية والملاحظات على الأرض لاختبار فرضياتها، استخدمت هذه الدراسة البرنامجين Smart V.3.4 وSPSS V.28، فضلا عن تقنيات الإحصاء الوصفي، أما أبرز النتائج التي توصل إليها البحث فكانت قدرة هيئة النزاهة الاتحادية على توظيف شفافيتها التنظيمية في تحسين رقابتها الإدارية من خلال اعتمادها على تبين استثمار هيئة النزاهة شفافيتها التنظيمية في تحسين رقابتها الإدارية بشكل جيد، لاسيما وأنها اعتمدت الوضوح في الإجراءات والإفصاح عن المعلومات والاتصال بشكل مجتمع في تحسينها، فيما وضعت توجها لتحسين فاعلية رقابتها الإدارية بتوظيف الوضوح في الإجراءات، بينما حقق أهداف الرقابة الإدارية من خلال أبعاد الشفافية التنظيمية الثلاث، فضلاً عن تحسينها وسائل الرقابة الإدارية من خلال تبني الوضوح في الإجراءات والإفصاح عن المعلومات، واخيراً اعتمدت الهيئة على الوضوح في الإجراءات والاتصال لتحسين مستوى أنشطتها الرقابية، وفي نهاية البحث حاول الباحث بالخروج بمجموعة من الاقتراحات التي تساعد على تحسين الرقابة الإدارية للهيئة المدروسة، منها ضرورة اهتمام هيئة النزاهة بوضوح اجراءاتها وبما يسهم في تعزيز شفافيتها بتوضيح اجراءات العمل واعتماد اساليب توضيح تكسب مهامها، وكذلك ينبغي على هيئة النزاهة بالإفصاح عن المعلومات بالإفصاح عن المعلومات وبما يحسن من شفافيتها من خلال تبني معايير افصاح تحافظ من خلالها على ميزاتها التنظيمية، واشاعة ثقافة التشارك المعرفي والمعلوماتي.