In this current work, Purpose; to clearly the fundamental idea for constructing a design and
investigation of spur gear made of composite material its comes from the combination of (high
speeds, low noise, oil-les running, light weight, high strength, and more load capability)
encountered in modern engineering applications of the gear drives, when the usual metallic gear
cannot too overwhelming these combinations.
An analyzing of stresses and deformation under static and dynamic loading for spur gear tooth
by finite element method with isoparametric eight-nodded in total of 200 brick element with 340
nods in three degree of freedom per node was selected for this analysis. This is responsible for the
catastropic failure studying of spur gear made of composite material. Also obtain the natural
frequencies and the mode shape of the composite tooth under (concentrated and or moving on
surface profile) load of one half sinusoidal type impulse for two types of composite materials
(Glasses/Epoxy & Graphite/Epoxy) and they are compared with the mild steel gear values.
The appearances that improve the successfully of composite gear in the weight, stiffness, load
capability, and dynamic behavior respect to the mild steel, which is found that composite materials
may also be thought of as a material for power transmission gearing, from a stress point of view.
The impact of exposure to different sizes of particulate matter (PM1, PM2.5, PM7, and PM10) was evaluated in Babylon concrete plant workers who had been exposed to concrete dust for at least 10 years. The effects of these particles on the hematological parameters, malondialdehyde (MDA) levels, and antioxidant enzymes (catalase and glutathione peroxidase ) were examined. The results exhibited that the levels of PM2.5 and PM10 were higher than the acceptable limits approved by the National Ambient Air Quality Standards (NAAQS). The blood parameters, namely white blood cells (WBC), red blood cell (RBC) and platelets counts, demonstrated non-significant differences between workers exposed to the PM as compared to the control gro
... Show MoreThe effect of alcoholic extract (2%,4%, 12%) and the fruits aqueous extract (12%,15%,25%,35%) of Melia azedarach and actellic insecticide of 0.01 concentration were tested on the second instar larvae ofOryzaephilus surinamensis .The obtained resuls were reveated that the highest kill ratio 80% at the concentration 12% of the alchoholic extract and 85% of the aqueous extract this was reflected effect abstracts on low rate of age adult emerging of larve treated and low productivity
Background: Titanium implant is widely used in dentistry because of its extraordinary biocompatibility and mechanical properties. To increase bone–implant connection and provide early loading after placement, implant is stored in different storage medium and treated with UV light. Both of them are applicable methods to increase the bioactivity of titanium and overcome the biological aging. This study was designed to assess the effect of vacuum storage method and air storage with and without UV light treated of Cp Ti implant mechanically and histologically. Materials and methods: Titanium screws were acid etched and prepared in four different modes using different storage methods (air or vacuum and, with or without UV treatment. The implan
... Show MoreBackground: Recurrent Aphthous Stomatitis (RAS) is the most common painful oral mucosal disease, affecting approximately 20% of the population. RAS presents with a wide spectrum of severity ranging from a minor nuisance to complete debility. Many of factors thought to have been involved in its etiology; that might have at the same time a direct or indirect impact upon oxidant/antioxidant system and trigger free radicals production. The aim of this study was to determine the possible association of oxidant/total antioxidant status and recurrent aphthous stomatitis (RAS). Subjects, materials and methods: The study consisted of thirty patients with recurrent aphthous stomatitis and thirty healthy controls from which saliva and blood samples we
... Show MoreStaphylococcus aureus is one of the common causative agents of infections, from asymptomatic carriers to healthy individuals. It can colonize anterior nares of carriers with a high capability to resist different antibiotics. Students are susceptible to bacterial infection due to some factors, including poor health habits and surrounding school conditions. This study screened the rate of vancomycin- and methicillin- resistant Staphylococcus aureus nose carriers among secondary students in rural and urban schools and its association with some sociodemographic factors. The study sample included 300 male/female students aged 15-20 years from 12 schools of rural and urban areas during the period from November 2020 till May 2021. It was fo
... Show MoreThis research sheds light on those discrepancies in the use of ornaments, adornment and perfumes, as well as the art of cosmetics, in two important civilizations, namely, the Mesopotamian civilization as the earlier civilization, and the civilization of Yemen, which represents the first Arab civilization. Through the foregoing, our research includes two topics, the first topic included the history of the use of decorations, ornaments and perfumes in the civilization of Mesopotamia, while the second topic included the study of ornaments, adornment and cosmetic art in the ancient civilization of Yemen. And then the research came out with a number of conclusions that the researcher considers very important to highlight the differences and f
... Show MoreTaking into account the significance of food chains in the environment, it demonstrates the interdependence of all living things and has economic implications for people. Hunting cooperation, fear, and intraspecific competition are all included in a food chain model that has been developed and researched. The study tries to comprehend how these elements affect the behavior of species along the food chain. We first examined the suggested model's solution properties before calculating every potential equilibrium point and examining the stability and bifurcation nearby. We have identified the factors that guarantee the global stability of the positive equilibrium point using the geometric approach. Additionally, the circumstances that would gu
... Show MoreVerbs are an important material in the construction of the sentence, as they are among the requirements of every sophisticated language, and in this regard, Ibn Al-Gothic (d. 367 AH): “Know that verbs are the origins of the buildings of most speech, and thus scholars called them buildings.” Verbs are the source of expression of the speakers’ ideas to represent the element of activity and movement, and with their knowledge We infer the meanings of Arabic words, and Ibn Al-Sarraj (d. 316 AH) defined it: “The verb denotes a meaning and a time, and that time is either past, present, or future.” Its letters are original and does not drop from its construction a letter in the conjugation of its conjugations, and it is in Arabic two type
... Show More(Sepak takraw) is a game that mixes football and volleyball, it is played on a court similar to a badminton court, in which players have the right to play the ball with any part of the body except the arm and hand. The object of the game is to return the ball to the opponent's court and score a point. Since it is a newly emerging game, all aspects related to it must be studied and covered in order to reach the highest levels, and it is known that each game or sporting activity has its own physical and motor capabilities, which is important to determine the level of technical performance, as the game's abilities contribute to mastering the skills. The importance of research in determining standard levels of physical and motor abilities for y
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