Cantilever beams are used in many crucial applications in machinery and construction. For example, the airplane wing, the microscopic probe for atomic force measurement, the tower crane overhang and twin overhang folding bridge are typical examples of cantilever beams. The current research aims to develop an analytical solution for the free vibration problem of cantilever beams. The dynamic response of AISI 304 beam represented by the natural frequencies was determined under different working surrounding temperatures ((-100 ℃ to 400 ℃)). A Matlab code was developed to achieve the analytical solution results, considering the effect of some beam geometrical dimensions. The developed analytical solution has been verified successfully with real experimental data and the error was not exceeded 1%. Keywords: analytical solution, cantilever beam, free vibration, mathematical modeling.
Low-temperature stratification, high-volumetric storage capacity, and less-complicated material processing make phase-changing materials (PCMs) very suitable candidates for solar energy storage applications. However, their poor heat diffusivities and suboptimal containment designs severely limit their decent storage capabilities. In these systems, the arrangement of tubes conveying the heat transport fluid (HTF) plays a crucial role in heat communication between the PCM and HTF during phase transition. This study investigates a helical coil tube-and-shell thermal storage system integrated with a novel central return tube to enhance heat transfer effectiveness. Three-dimensional computational fluid dynamics simulations compare the proposed d
... Show MoreAs a result of rapid industrialization and population development, toxic chemicals have been introduced into water systems in recent decades. Because of its excellent efficiency and simple design, the three-dimensional (3D) electro-Fenton method has been used for the treatment of wastewater. The goal of the current study is to explore the efficiency of phenol removal by the 3D electro-Fenton process, which is one of the advanced oxidation processes (AOPs). In the present work, the effect of the addition of granular activated carbon (GAC) particles to the electro-Fenton system as the third electrode would be investigated in the presence of graphite as the anode and nickel foam as the cathode, which is the source of electro-generated hydrogen
... Show MoreSome genetic factors are not only involved in some autoimmune diseases but also interfere with their treatment, Such as Crohn's disease (CD), Rheumatoid Arthritis (RA), ankylosing spondylitis (AS), and psoriasis (PS). Tumor Necrosis Factor (TNF) is a most important pro-inflammatory cytokine, which has been recognized as a main factor that participates in the pathogenesis and development of autoimmune disorders. Therefore, TNF could be a prospective target for treating these disorders, and many anti-TNF were developed to treat these disorders. Although the high efficacy of many anti-TNF biologic medications, the Patients' clinical responses to the autoimmune treatment showed significant heterogeneity. Two types of TNF receptor (TNFR); 1 an
... Show MoreThis paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance be
... Show MoreThe aim of this research is to apply the concept of total value management to improve the process design of producing the toothpaste in Al Mammon factory one of the in the general company of food industry. The concept of total value management is concerning with achieve more than one values which are important for the customers as these values are related to the customers satisfaction. The research problem is that the factory did not measure the effectiveness of process design as this company has weakness in analyzing this effectiveness in synchronies with total value management. On the other side, the company did not give more attention to the cost of products and selling prices within the value cost/ profit which is one of the
... Show MoreThe research tried to show the importance of Administrative Control being one of the important means in administrative work; they work on the review and audit work done and error handling explored in the work and prevent the occurrence and ascertain the extent of implementation of the planned targets, and therefore this is reflected in raising the efficiency of the performance of the tax examiner and complete the work as soon as possible and the highest efficiency and reduce the gaps that may occur between the parties of the tax settling accounts and dealt with in the theoretical side of the search to the research problem, namely with whether operating management oversight to improve the performance and increase the efficiency of t
... Show MoreA large number of natural or synthetic dyes have been removed from both national and international lists of permitted food colors because of their mutagenic or carcinogenic activity. Therefore, this study aimed to use the Random Amplified Polymorphic DNA-Based Polymerase Chain Reaction (RAPD-PCR) assay as a feasible method to evaluate the ability of some food colors as genotoxin-induced DNA damage and mutations. Lactiplantibacillus plantarum was used as a bioindicator to determine the genotoxic effects by RAPD-PCR using M13 primer after treatment with some synthetic dyes currently used as food color additives, including Sunset Yellow, Carmoisine, and Tartrazine. Besides qualitative analysis, the bioinformatic GelJ software was used for clus
... Show MoreObjectives To tailor composites of polyethylene–hydroxyapatite to function as a new intracanal post for the restoration of endodontically treated teeth (ETT). Methods Silanated hydroxyapatite (HA) and zirconium dioxide (ZrO2) filled low-density polyethylene (LDPE) composites were fabricated by a melt extrusion process and characterised using infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The flexural strength and modulus were determined in dry state and post ageing in simulated body fluid and fractured surfaces analysed by SEM. The water uptake and radiographic appearance of the experimental composites were also measured and compared with a commercially known endodontic fibre
... Show MoreBackground: University dental students perceived a higher level of stress prior to the final exam associated with raised salivary alpha-amylase levels which could be considered as a useful noninvasive biomarker for measuring acute stress. Using a Helkimo anamnestic and clinical dysfunction scoring for temporomandibular disorders can give a better insight about the association of this marker and temporomandibular disorders. The aim of this study was to evaluation level of salivary alpha-amylase in stressor students with temporomandibular disorders and the relation between the marker in relation to temporomandibular disorders severity. This might give a better understanding to the role of psychological stress as an etiological factor for deve
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