Conjugate heat transfer has significant implications on heat transfer characteristics, particularly in thick wall applications and small diameter pipes. In this study, a three-dimensional numerical investigation was carried out using commercial CFD software “ANSYS FLUENT” to study the influence of conjugate heat transfer of laminar flow in mini channels at constant heat flux wall conditions. Two parameters were studied and analyzed: the wall thickness and thermal conductivity and their effect on heat transfer characteristics such as temperature profile and Nusselt number. Thermal conductivity of (0.25, 10, 202, and 387) W/m2C and wall thickness of (1, 5, and 50) mm were used for a channel of (1*2) mm cross-sectional dimensions. Taking the Reynolds number 800 for all cases. The results demonstrate that the conjugate conduction impact is observed at high conductivities and for large wall thicknesses in the studied materials. This impact flattened the wall temperature distribution along the channel wall instead of being an augmented linear profile. Also, it flattens the local Nusselt number due to the axial heat conduction along the walls. It reduces the effect of the entrance region of high Nusselt number while making the fluid temperature profile curved and redistributing the wall heat flux and accumulating it toward the leading edge. A decrease was observed in the average Nusselt number of 8% when increasing wall thickness from 1 mm to 50 mm for the same thermal conductivity of 10 W/m2C, while an increase in Nusselt number of 19% with thermal conductivity changes from 0.25 W/m2C to 10 W/m2C.
A simple, rapid, accurate and sensitive spectrophotometric method for the determination of thiaminehydrochloride has been developed. The method is based on the formation of the Schiff’s base between the primary amino group present in thiamine hydrochloride and aldehyde group present in the vanillin reagent to produce a yellow colored complex having maximum absorption at 390 nm. Beer’s law has obeaid over the concentration range of 2-28µg/mL, with molar absorptivity of 0.96x104L/mol.cm. The average recovery which is a measure of accuracy is 100±1.3% and the relative standard deviation (RSD) is less than1.5 .The present method is considered to be
... Show MoreReview of multidrug sensitivity and resistance in enterococcus
Impact of buildings in Iraq and other countries on the environment is obvious; this problem began to take scientific and humanitarian dimensions in order to reduce and eliminate this problem. This impact can be seen through the energy, water and raw materials consumed for the establishment, operation and maintenance of these buildings, as well as the emissions of hazardous gases and generations of solid wastes.
This work was conducted to assess the current maintenance managerial practice for the governmental buildings to stand on the main obstacle and extrapolation of measures by means of interviews with experts to determine the effective factors and closed questionnaire to state the features and the need for new
... Show MoreThere is talk of the Prophet ﷺ proud of his relative, which is the uncle, and the importance of this subject, this search for doctrinal matters related to the two things between us: the interest of the Prophet ﷺ responsible, and also responsible forbidden marriage and marriage as it is forbidden to marry the uncle, and in the uncle language: mother's brother, aunt Her uncle may spend his uncle's nephew, the uncle may embrace his nephew, the uncle shall be the guardian of the little or the small, not to cut off the uncle if he steals from his nephew's money. "
In this work gold nanoparticles (AuNPs), were prepared. Chemical method (Seed-Growth) was used to prepare it, then doping AuNPs with porous silicon (PS), used silicon wafer p-type to produce (PS) the processes doping achieved by electrochemical etching, the solution etching consist of HF, ethanol and AuNPs suspension, the result UV-visible absorption for AuNPs suspension showed the single peak located at ~(530 – 521) nm that related to SPR, the single peak is confirmed that the NPs present in the suspension is spherical shape and non-aggregated. X-ray diffraction analysis indicated growth AuNPs with PS. compare the PS layer without AuNPs and with AuNPs doped for electrical properties and sensitivity properties we found AuNPs:PS is more
... Show MoreInternational law has proven that it is an evolving and flexible law over the years, and despite that, this development takes a very long time, as the concept of peremptory norms took 83 years to crystallize and have concrete and impactful applications, and within this development another modern concept emerged, which is the obligations Erga Omnes in the Barcelona Traction case 1970. We have concluded that these two concepts fall under a broader concept, which is peremptory norms, and this concept represents the common supreme interests of the international community, and consists of rules that transcend all other rules in international law, and it is not permissible to derogate or deviate from them. On the other hand, it bears the oblig
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