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A system of several fraction laws for the identification of rotating response of FG shell
Yahya, Ahmad,Hussain, Muzamal,Khadimallah, Mohamed A.,Khedher, Khaled Mohamed,Al-Basyouni, K.S.,Ghandourah, Emad,Banoqitah, Essam Mohammed,Alshoaibi, Adil Techno-Press 2022 Advances in concrete construction Vol.13 No.3
The problem is formulated by applying the Kirchhoff's conception for shell theory. The longitudinal modal displacement functions are assessed by characteristic beam ones meet clamped-clamped end conditions applied at the shell edges. The fundamental natural frequency of rotating functionally graded cylindrical shells of different parameter versus ratios of length-to-diameter and height-to-diameter for a wide range has been reported and investigated through the study with fractions laws. The frequency first increases and gain maximum value with the increase of circumferential wave mode. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing height-to-radius ratio. Moreover, on increasing the rotating speed, the backward frequencies increases and forward frequencies decreases. The trigonometric frequencies are lower than that of exponential and polynomial frequencies. Stability of a cylindrical shell depends highly on these aspects of material. More the shell material sustains a load due to physical situations, the more the shell is stable. Any predicted fatigue due to burden of vibrations is evaded by estimating their dynamical aspects.
Impact resistance efficiency of bio-inspired sandwich beam with different arched core materials
Ahmad B.H. Kueh,Chun-Yean Tan,MOHD YAZID YAHYA,Mat Uzir Wahit 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.44 No.1
Impact resistance efficiency of the newly designed sandwich beam with a laterally arched core as bio-inspired by the woodpecker is numerically investigated. The principal components of the beam comprise a dual-core system sandwiched by the top and bottom laminated CFRP skins. Different materials, including hot melt adhesive, high-density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), epoxy resin (EPON862), aluminum (Al6061), and mild carbon steel (AISI1018), are considered for the side-arched core layer of the beam for impact efficiency assessment. The aluminum honeycomb takes the role of the second core. Contact force, stress, damage formation, and impact energy for beams equipped with different materials are examined. A diversity in performance superiority is noticed in each of these indicators for different core materials. Therefore, for overall performance appraisal, the impact resistance efficiency index, which covers several chief impact performance parameters, of each sandwich beam is computed and compared. The impact resistance efficiency index of the structure equipped with the AISI1018 core is found to be the highest, about 3-10 times greater than other specimens, thus demonstrating its efficacy as the optimal material for the bio-inspired dual-core sandwich beam system.
Ahmad Mubarak Hussaini,Zezi Abdulkadir Umar,Anafi Sherifat Bola,Alshargi Omar Yahya,Mohammed Mustapha,Mustapha Sagir,Bala Auwal Adam,Muhammad Surajuddeen,Julde Sa’adatu Muhammad,Wada Abubakar Sadiq,Ja 한국독성학회 2022 Toxicological Research Vol.38 No.4
The plant Combretum hypopilinum Diels (Combretaceae) has been utilized in Nigeria and other African nations to treat many diseases including liver, inflammatory, gastrointestinal, respiratory, infectious diseases, epilepsy and many more. Pharmacological investigations have shown that the plant possesses anti-infective, antidiarrhoeal, hepatoprotective, antiinflammatory, anticancer, sedative, antioxidant, and antiepileptic potentials. However, information on its toxicity profile is unavailable despite the plant's therapeutic potential. As such, this work aimed to determine the acute and sub-acute oral toxic effects of the hydromethanolic leaves extract of C. hypopilinum. The preliminary phytochemical evaluation was carried out based on standard procedures. The acute toxicity evaluation was conducted by oral administration of the extract at the dose of 5000 mg/kg based on the guideline of the Organization of Economic Co-operation and Development (OECD) 423. To investigate the sub-acute toxicity effects, the extract was administered orally to the animals daily for 28-consecutive days at the doses of 250, 500, and 1000 mg/kg. Mortality, body weight and relative organ weight were observed. The hepatic, renal, haematological, and lipid profile parameters were investigated. The liver, kidney, heart, lung, small intestine, and stomach were checked for any histopathological alterations. The results of the phytochemical investigation showed cardiac glycosides, tannins, steroids, flavonoids, alkaloids, saponins, and triterpenes. Based on the acute toxicity investigation outcome, no death and signs of toxic effects were observed. The result showed that the oral median lethal dose ( LD50) of the extract was more than the 5000 mg/kg. The extract remarkably reduced the weekly body weight of the animals at 500 mg/kg in the first and second weeks. It also significantly decreased the relative kidney weight, alkaline phosphatase, glucose, potassium, and low-density lipoprotein. There was a remarkable elevation in the percentage of eosinophils, basophils, monocytes, and granulocyte. There were histopathological abnormalities on the kidney, lung, stomach, and small intestine. The extract is relatively safe on acute exposure but moderately toxic at higher doses on sub-acute administration, particularly to the kidney.
A novel desulfurization practice based on diesel acidification prior to activated carbon adsorption
Mohammad Ahmad Al-Ghouti,Yahya Salem Al-Degs 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.4
Commercial diesel is often rich with organosulfur compounds and a value of 7,100 mgS/kg was recentlyreported. As confirmed by chromatographic analysis, about 36% of sulfur compounds are originated from dibenzothiophene. Following uncommon desulfurization method, organosulfur compounds were efficiently removed upon dieselacidification by organic acids prior to activated carbon adsorption. Protonation of S-containing compounds has enhancedtheir uptake by activated carbon. Competitive adsorption of di/tri/tetra-aromatics and dibenzothiophene fromsynthetic fuel proved that the later solute was preferentially removed against other aromatics upon fuel acidification. Results showed that 48% of organosulfur compounds were eliminated upon adding acetic acid to a final content of 3%by vol.. Principal component analysis indicated that acid content and carbon mass are the most significant factors onorganosulfur compounds removal: %Removal=5.8 (Acid Content)+6.3 (Mass)−0.02 (PD)−0.90 (Temp). The practicalefficiency of the proposed method was demonstrated by removing organosulfur compounds from commercial diesel.
Ali Asghar,Mohd Rozi Ahmad,Mohamad Faizul Yahya 한국의류학회 2016 Fashion and Textiles Vol.3 No.1
Of late, a significant amount of research has been carried out using metals for conductive fabrics and composites to obtain the desired level of electromagnetic shielding along with physical and mechanical properties for its durability. However, incorporating these metallic filaments as core or as an integral part of core deteriorate the mechanical properties of textile yarns and ultimately the fabrics’. Moreover, the transparency of fabrics to high frequency/smaller wavelength waves further increases with the attempt to increase the metallic filament diameter. This study, therefore analyses the effects of metallic filament alignment in order to improve the mechanical properties of the resultant hybrid yarns, and devises an alternative method to increase the amount of conductive filament without increasing the diameter of the conducting wire in hybrid yarn structures. The results suggest that the tensile properties of the proposed hybrid cover yarns with conductive filament as covering component is superior as compared to the yarns having a conductive filament in the core, however, the electrical resistance increases with an increase in conductive filament length. The tenacity, elongation and initial modulus values were enhanced several times by incorporating the conductive filament as spiral covering. Moreover, with the proposed alignment method, the amount of copper in hybrid yarn can be increased up to some extent by changing the number of turns of covering component.