This research introduces a developed analytical method to determine the nominal and maximum tensile stress and investigate the stress concentration factor. The required tooth fillets parametric equations and gears dimensions have been reformulated to take into account the asymmetric fillets radiuses, asymmetric pressure angle, and profile shifting non-standard modifications. An analytical technique has been developed for the determination of tooth weakest section location for standard, asymmetric fillet radiuses, asymmetric pressure angle and profile shifted involute helical and spur gears. Moreover, an analytical equation to evaluate gear tooth-loading angle at any radial distance on the involute profile of spur and helical gears, (taking into account the effect of profile shift factor) has been derived. In addition, numerical solution for the evaluation of the maximum fillet tensile stress and the combined tensile stress concentration factor for the verification of the analytical method using computer-aided engineering software (ANSYS Version 18.1). The analytical and FE result have been compared and found to be very close. The most effective method for reducing the stress concentration factor have been found by applying negative profile shifting on asymmetric tooth with lower unloaded pressure angle and high loaded pressure angle and fillet radius, which can lead to an enhancement percentage of (20%) when using a (35o/20o) asymmetric spur gear of a (24) teeth number with a shift factor of (-0.3mo) compared with standard (20o) one.
Yucca gloriosa Variegata L. is a stemless. The whole plant of Y. gloriosa L. has vast medicinal uses. TheNative Americans and North New Mexico used a tea from the leaves and roots to treat asthma, headache,wound healing. As well as it was being consumed as daily dietary. All part of Y. gloriosa L. is rich in saponinsteroidal glycosides. Saponin extracts are well-known to be highly toxic. Hence, present study was carriedout to investigate the toxicity of saponin and estimate the LD50 value which helps in determining the safedose range for the drug that be used, as well as to determine hematological aspects and examine histologicaleffect. Different concentrations of saponin extract were injected into male mice (10,000, 8000, 6000, 400
... Show MoreThe aim of this study is to understand the effect of addition carbon types on aluminum electrical conductivity which used three fillers of carbon reinforced aluminum at different weight fractions. The experimental results showed that electrical conductivity of aluminum was decreased by the addition all carbon types, also at low weight fraction of carbon black; it reached (4.53S/cm), whereas it was appeared highly increasing for each carbon fiber and synthetic graphite. At (45%) weight fraction the electrical conductivity was decreased to (4.36Scm) and (4.27Scm) for each carbon fiber and synthetic graphite, respectively. While it was reached to maximum value with carbon black. Hybrid composites were investigated also; the results exhibit tha
... Show MoreSeveral specimens of the avocet, Recurvirostra avocetta L. are found infected with
Himantocestus gigantivcus sp. nov. ( Cestoda , Diploposthidae) . This cestode is related to H.
blanksoni Ukoli 1965 but easily differentiated from it in having longer and wider strobila,
larger size of testes but lesser in number, cirrus situated in the middle of mature segment
histead of anterior third and slightly posterior to the middle in gravid segment instead of the
middle , ovary and vitelline gland are larger , and the uterus has more branches.
In the lifetime process in some systems, most data cannot belong to one single population. In fact, it can represent several subpopulations. In such a case, the known distribution cannot be used to model data. Instead, a mixture of distribution is used to modulate the data and classify them into several subgroups. The mixture of Rayleigh distribution is best to be used with the lifetime process. This paper aims to infer model parameters by the expectation-maximization (EM) algorithm through the maximum likelihood function. The technique is applied to simulated data by following several scenarios. The accuracy of estimation has been examined by the average mean square error (AMSE) and the average classification success rate (ACSR). T
... Show MoreThis study exposed to use the liquid whey (which was produced from of soft cheese processed) partially or completely instead of milk in fatty cake, this whey residue is still not used, instead it is thrown in rivers which effect different environment and economic problems. Different concentrations was used (25% , 50% , 75% , and 100%) of whey in baked cake , Volume , height and other different properties ( panel taste ) was studied too . Sensory evaluation results showed that an improved in all the character of the baked cake was happen by the used of 25% and 50% of the whey in comparison with the control treatment, the 75% replacement showed a decrease in appearance , texture and tenderness , while the degrees of color and fla
... Show MoreThe life insurance marketing faces many difficulties because it is not a current tangible commodity, so it needs a planning for promotional activities and data about prospective applicants according to many factors such as age and residence area , marital status and profession to determine the group wich need insurance covers. &nb
... Show MoreThis research includes a detailed morphological description of the Pollenia mesopotamica sp. nov. in Iraq. Locality, host plant and data of collection were given.