Evaluation of HFMI as a Life Extension Technique for Welded Bridge Details

Published by Elsevier B.V. In this current study, HFMI technique is used to study the possibility to extend the fatigue life of pre-fatigued flange gusset welds typically found in girder bridges. The results from the study are also compared with results found in the literature for other more conventional techniques for retrofitting, e.g. cut-outs. The study also aims to investigate if the IIW HFMI recommendations could be applied for existing steel structures and that equal fatigue strength improvement could be claimed for prefatigued structures. Furthermore, new recommendations for structural hot spot stress type B are suggested for HFMI treated welds, applicable to flange guest welds. The results indicate that the HFMI could be used for welded bridge details rehabilitation as a competing technology with conventional cut-out. Furthermore, the results indicate that the IIW recommendations for HFMI fatigue strength improvement could also be applied for pre-fatigued welded details. \ua9 2019 The Authors

Maximum allowable delay bound estimation using Lambert W function

The widespread of communication networks make them very promising to play a great role in future control systems. The communication networks will be present in the feedback control system which makes it a kind of time delay system. Closing the feedback system through a communication network introduces many challenges for the controller designers. Communication networks induce inherent time delay and some of the data may be lost which can destabilize the control system or result in poor system performance. It is important to identify the maximum time delay that the control system can withstand. In this paper, we report the application of the Lambert W function for calculating the maximum allowable delay bound in linear time delay control systems. The results of the calculation are compared with the most widely used Linear Matrix Inequalities based method. © 2017 IEEE

Ecological Study of Iris unguicularis cretensis in the Coastal Region of Syria في المنطقة الساحلية من سورية (Iris unguicularis cretensis) دراسة بيئية لنبات سوسن كريت

This search was conducted during 2014 - 2017 in order to determine the distribution area of Iris unguicularis cretensis in the coastal region of Syria, to evaluate the current situation of its habitats, and to determine the best method to reproduce this plant and evaluate its nutritive value as forage. The distribution area was identified through 12 field trips at various types of parent rocks, expositions, and altitudes along the western versant of the coastal mountains in Syria. The properties of natural habitat was examined in 37 samples distributed along a gradient extending from 300 to 1000 m above sea level. Habitat data concerning topography, soil surface characteristics, accompanist plants, habitat type, characteristics of colonies, was collected. Seed germination of four treatments each contain six replicates (36 seeds) and vegetative propagation by rhizomes, have been tested. Nutritive value as forage was estimated by analyzing the chemical composition of its leaves in ACSAD laboratories. The results showed that Iris unguicularis cretensis occurs in abundance in the coastal region of Syria within diverse conditions of habitats, mainly at the edges of conifer and oak degraded forests, accompanied by degraded vegetation of Cistus salviifolius and Genista acanthoclada . Concerning the germination tests, results showed that soaking Iris seeds in water for 24 hours before planting, was significantly the best treatment. The study showed also the possibility of propagating Iris successfully with rhizomes. Leaves have a good nutritive value as a forage, and animals feed on it in late summer what generally mitigates the impact of overgrazing. This study provides important information about the ecology of this plant. تم إجراء البحث خلال الفترة من 2014إلى2017 بهدف حصر أماكن انتشار سوسن كريت في الساحل السوري وتقيــيم الواقع الحالي لموائله، ومن ثم تحديد الطرائق الأفضل لإكثاره وأهميته العلفية. حددت مواقع انتشار السوسن من خلال 12 جولة ميدانية على أشكال متنوعة من الصخور الأم وعلى ارتفاعات ومعارض مختلفة على امتداد السفح الغربي للجبال الساحلية في سورية، ودرست خصائص الموئل الطبيعي في 37 عينـة منها تتوزع على محور يمتد من ارتفاع 300 وحتى 1000م عن سطح البحر. تم جمع البيانات المتعلقة بالموئل مــن خلال استمارة احتوت على البيانات الأساسية المتعلقة بطبوغرافية الموقع، وخصائص سطح التربة، الغطاء النباتي، ونوع الموئل إضافة للأنواع النباتية المرافقة وعدد الباقات ومساحتها وعدد الأزهار في الباقة الواحدة. من ناحية أخرى تم اختبار انبات البذور تحت أربعة معاملات احتوت كل منها على ستة مكررات (36 بذرة) كما تم اختبار امكانيــة الاكثار الخضري بوساطة الجذامير من خلال عينة من 12 جذموراً. كما قدّرت القيمة العلفية للنبات من خلال تحليــل التركيب الكيميائي لأوراقه في مخابر أكساد. أظهرت النتائج انتشار سوسن كريت بوفرة في الساحل السوري ضمن موائل متنوعة بظروفها النبتية والطبوغرافية والأرضية وحيث تتوفر كمية كافية من الإضاءة (أطراف الغابات الصنوبرية والسنديانية المتدهورة بشكل أســـــــاس) مترافقاً بنبت تدهوري تسود فيه القريضة Cistus salviifolius والشويك Genista acanthoclada في أغلب المواقع. فيما يخص إكثار السوسن فقد أظهرت النتائج تفوق معاملة نقع البذور في الماء العادي لمدة 24 ساعة قبل الزراعة معنوياً على بقية المعاملات الأخرى للإكثار البذري، كما أظهرت إمكانية إكثار سوسن كريت خضرياً بسهولة من خلال تجزئة الجذامير. وأظهرت النتائج أن أوراق السوسن تتمتع بقيمة علفية جيدة وتقبل عليها الحيوانات في أواخــــــــــر الصيف عموماً ما يخفف من تأثير الرعي الجائر عليها. وأخيراً تقدم هذه الدراسة معلومات مهمة حول بيئة هذا النوع

D. AFSHARI et al.: PREDICTION OF THE NUGGET SIZE IN RESISTANCE SPOT WELDING ... PREDICTION OF THE NUGGET SIZE IN RESISTANCE SPOT WELDING WITH A COMBINATION OF A FINITE-ELEMENT ANALYSIS AND AN ARTIFICIAL NEURAL NETWORK NAPOVEDOVANJE PODRO^JA PRETALITVE PRI

The goal of this investigation is to predict the nugget size for a resistance spot weld of thick aluminum 6061-T6 sheets 2 mm. The quality and strength of spot welds determine the integrity of the structure, which depends thoroughly on the nugget size. In this study, the finite-element method and artificial neural network were used to predict the nugget size. Different spot welding parameters such as the welding current and the welding time were selected to be used for a coupled, thermal-electrical-structural finite-element model. In order to validate the numerical results a series of experiments were carried out and the nugget sizes were measured. The results obtained with the finite-element analysis were used to build up a back-propagation, artificialneural-network model for the nugget-size prediction. The results revealed that a combination of these two developed models can accurately and rapidly predict the nugget size for a resistance spot weld. Keywords: resistance spot weld, nugget size, finite-element analysis, artificial neural network, aluminum alloys Cilj te preiskave je napovedati velikost podro~ja pretalitve pri uporovno zvarjeni aluminijasti plo~evini 6061-T6, debeli 2 mm. Kvaliteta in trdnost to~kastega zvara dolo~ata celovitost konstrukcije, kar je odvisno predvsem od velikosti podro~ja pretalitve. V tej {tudiji sta bili za napovedovanje velikosti podro~ja pretalitve uporabljeni metoda kon~nih elementov in umetna nevronska mre`a. Izbrani so bili razli~ni parametri varjenja, kot sta varilni tok in~as varjenja, za skupni termi~no-elektri~no-strukturni model kon~nih elementov. Za oceno numeri~nih rezultatov je bilo izvr{enih ve~preizkusov in izmerjena je bila velikost podro~ja pretalitve. Rezultati, dobljeni iz analize kon~nih elementov, so bili uporabljeni za gradnjo modela umetne nevronske mre`e za napovedovanje velikosti podro~ja pretalitve. Rezultati so odkrili, da kombinacija teh dveh razvitih modelov lahko zanesljivo in hitro napove velikost podro~ja pretalitve pri uporovnem to~kastem zvaru. Klju~ne besede: uporovni to~kasti zvar, velikost podro~ja pretalitve, analiza kon~nih elementov, umetna nevronska mre`a, zlitine aluminij

Effects of sand and gating architecture on the performance of foot valve lever casting components used in pump industries

Funding Information: The authors thank Kalasalingam Academy of Research and Education, Krishnankoil for providing the facilities for various tests and characterizations. The King Saud University authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project no. RG-148. This Research was funded by King Mongkut's University of Technology North Bangkok has received funding support from the National Science, Research and Innovation Fund (NSRF) (Grant No. KMUTNB-MHESI-64-16.1). Publisher Copyright: © 2021 The Author(s)This work addresses manufacture, testing and simulation of foot valve lever (FVL) for monoblock pump industry, using a cost-effective casting design process. The impact of different types of sands, such as air-set, dry and sodium silicate as well as gating designs, namely H-, U- and O-type, were studied with respect to surface roughness and porosity. The mold pattern was produced using additive manufacturing (AM) technology. Both experimental and numerical investigations were performed on the temperature distribution of molten metal at random locations for the different gating configurations or designs, considering mold filling and solidification. It was evident from the experimental investigation that contribution of air-set sand and O-type gating architecture showed limited consistency effects. Importantly, gating architecture was the most influential parameter to determine all specified quality outcomes, independent of sand mold. An order of O < H < U-type was obtained from the gating designs for minimal surface roughness and percentage of porosity. Furthermore, the microstructure analysis depicted only an irregular defect with minimum quantity at both surface and cross-section of O-type at two different locations. Optimum pouring temperatures of 740, 750 and 790 °C were obtained for mold filling of all 24 components of H-, O- and U-type of gating designs, respectively. The varying solidification temperature was observed from real time thermocouple reading, which was in close agreement with the numerical simulation. Evidently, O-type of gating design exhibited best performance for large-scale development of the FVL in terms of surface roughness, porosity and cooling effects.Peer reviewe

A comparison between solar thermal and photovoltaic/thermal (PV/T) systems for typical household in Libya

—The fossil fuel in Libya produces the most of the generated electricity. As the energy demand will escalate significantly in the near future, more oil and gas are consumed and hence more CO2 emission. Therefore, for a sustained development the renewable energy must share in the electricity market. The special location of Libya in the highest sunny belt makes the solar energy one of the best alternative energy supplier. This paper is aimed at proposing an effective solution to enhance continuous power availability and to reduce the peak load demand in Libyan electric grid through replacing the electric heaters with Domestic Solar Water Heating (DSWH). Two alternatives are analyzed; photovoltaic-solar water heating (PV-SWH) system and photovoltaic-photovoltaic/thermal (PVPV/T). The two options are compared in terms of the capital cost, maintenance cost, total cost, fuel cost and the CO2 emission. The results show that the total energy saving for the PV-SWH system is around 69.79% of the total energy required. Furthermore, the total energy saving for the PV-PV/T system is about 75.02% of the net energy need

Obesity is associated with insulin resistance and components of the metabolic syndrome in Lebanese adolescents

adolescents has been reported to range between 18–42%, depending on country of origin, thus suggesting an ethnicbased association between obesity and MS. Aim: This study aims to investigate the magnitude of the association between obesity, insulin resistance and components of MS among adolescents in Lebanon. Subjects and methods: The sample included 263 adolescents at 4 th and 5 th Tanner stages of puberty (104 obese; 78 overweight; 81 normal weight). Anthropometric, biochemical and blood pressure measurements were performed. Body fat was assessed using dual-energy X-ray absorptiometry. Results: According to International Diabetes Federation criteria, MS was identified in 21.2 % of obese, 3.8 % of overweight and 1.2 % of normal weight subjects. The most common metabolic abnormalities among subjects having MS were elevated waist circumference (96.2%), low HDL (96.2%) and hypertriglyceridemia (73.1%). Insulin resistance was identified in all subjects having MS. Regression analyses showed that percentage body fat, waist circumference and BMI were similar in their ability to predict the MS in this age group. Conclusions: MSwas identified in asubstantial proportion of Lebanese obese adolescents, thus highlighting the importance of early screening for obesity-associated metabolic abnormalities and of developing successful multi-component interventions addressing adolescent obesity

Sadri Computational Power of the Quantum Turing Automata

Lots of efforts in the last decades have been done to prove or disprove whether the set of polynomially bounded problems is equal to the set of polynomially verifiable problems. This paper will present an overview of the current beliefs of quantum complexity theorists and discussion detail the impacts these beliefs may have on the future of the field. We introduce a new form of Turing machine based on the concepts of quantum mechanics and investigate the domain of this novel definition for computation. The main object is to show the domain of these Computation machines and the new definition of Algorithms using these automata. In section one we give a brief fundamental overview of classical complexity theory, Turing machine and all the fundamental concepts required for the next chapters. In section two we describe various classes of classical complexity automata. In next chapter we introduce quantum complexity featuring Quantum Turing Machines and discuss its relationship to classical complexity. Section four presents a relationship between Quantum complexity classes based on the quantum Turing machines and Quantum oracles, and their relationship with corresponding classical complexity classes. And section five presents a discussion on the practical phenomena in problem solving using quantum computers. Finally in section five we speculate briefly on the direction we believe the field to be headed, and what might reasonably be expected in the future

The Effectiveness and Quality of Life Outcomes by Transoral Endoscopic Vestibular Thyroidectomy Using Intraoperative Indocyanin Green Fluorescence Imaging and Neuromonitoring—A Cohort Study

Background: Transoral endoscopic vestibular thyroidectomy (TOEVT), a variant of natural orifice transluminal endoscopic surgery, offers a scar-less thyroid to young females. However, few studies have compared the effectiveness and quality of life (QoL) outcomes of the TOEVT with open thyroidectomy (OT). This is the first study in the Middle East and North Africa region that compares the effectiveness, safety profile and QoL outcomes between TOEVT with OT. Methods: We reviewed the medical records of consecutive patients with TOETV and OT at Zulekha Hospital Sharjah and Dubai United Arab Emirates, between 1 January 2019 and 1 April 2021. The data for demographics, type of surgery, operative time, blood loss, post-operative nodule size, hospital stay and post-operative complications were analyzed. We used an SF-36 questionnaire pre- and postoperatively for the assessment of QoL in both groups. Findings: Out of a total of 41 OT and 32 TOEVT procedures, 59 patients (31 TOEVT and 28 OT) fulfilled the inclusion criteria. There were 45 women and 14 men with an average age of 41 years. The mean operating time was 126 min in TOEVT and 96 min in OT (p = 0.000). The mean thyroid size was 5.55 cm in TOEVT and 8.76 cm in OT (p = 0.000). Lastly, the mean intraoperative blood loss was 39 cc and 95.7 cc in TOEVT and OT, respectively (p = 0.001). There was one temporary hypocalcemia and seroma in TOEVT, four cases of temporary hypocalcemia and one with minor bleeding in OT. The post-operative QoL significantly improved in all patients. However, the QoL improved more significantly in the TOEVT group for bodily pain, vitality, role emotions and cosmetic concerns (p = 0.000). Conclusion: The safety profile and effectiveness of the TOEVT is comparable to the OT procedure. However, TOEVT has an additional advantage of being scarless and offers a better QoL