Among the different passive techniques heat pipe heat exchanger (HPHE) seems to be the most effective one for energy saving in heating ventilation and air conditioning system (HVAC). The applications for nanofluids with high conductivity are favorable to increase the thermal performance in HPHE. Even though the nanofluid has the higher heat conduction coefficient that dispels more heat theoretically but the higher concentration will make clustering .Clustering is a problem that must be solved before nanofluids can be considered for long-term practical uses. Results showed that the maximum value of relative power is 0.13 mW at nanofluid compared with other concentrations due to the low density of nanofluid at this concentration. For highe
... Show MoreSoaking dentures with disinfection solutions is an effective way of keeping dentures in a healthy status; however, immersions in these solutions have a negative effect on the bond strength of denture base and denture teeth. The aim of this study was to evaluate the bond strength between denture acrylic teeth and heat-cured Poly (methyl methacrylate) denture base material (with and without nano silica) after disinfection with different chemical disinfectants for a simulated period of six months. One hundred specimens of maxillary central incisors attached to PMMA were divided into two groups; 50 specimens of PMMA without nano silica and 50 specimens of PMMA reinforced with 5 wt% of nano silica. Specimens of each group were immersed in five i
... Show MoreThe removal of congo red (CR) is a critical issue in contemporary textile industry wastewater treatment. The current study introduces a combined electrochemical process of electrocoagulation (EC) and electro-oxidation (EO) to address the elimination of this dye. Moreover, it discusses the formation of a triple composite of Co, Mn, and Ni oxides by depositing fixed salt ratios (1:1:1) of these oxides in an electrolysis cell at a constant current density of 25 mA/cm2. The deposition ended within 3 hours at room temperature. X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and energy dispersive X-ray (EDX) characterized the structural and surface morphology of the multi-oxide sedim
... Show MoreDuration of each developmental stage of the house dust mite Dermatophagoides pteronyssinus together with the mortality percentage were observed at a combination of five different temperatures namely 20C°, 22.5C°, 25C°, 27.5C° and 30C° and four different humidities namely 55%, 75%, 85% and 95% r. h. Results showed that temperature had the greatest effect on the life cycle period. The higher the temperature the shorter the life cycle was aid versa verea. On the other hand, humidity seems to be less effectiveness, though at the higher temperature and humidity no development was occured. Mortality among all temperatures and humidities appeared nearly the same, but at higher temperature and higher humidity and because of mould g
... Show MoreThe effect of air injection angle on the performance of airlift pump used for water pumping has been studied analytically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90 (for conventional) to 45 and 22.5 (for modified). Continuity and one-dimensional momentum balance for the flow field with basic principle of two-phase flow and expressions of slip ratio and friction factor as function of flow rates were formulated. The analytical and experimental investigations were carried out f
... Show MoreMilling process is a common machining operation that is used in the manufacturing of complex surfaces. Machining-induced residual stresses (RS) have a great impact on the performance of machined components and the surface quality in face milling operations with parameter cutting. The properties of engineering material as well as structural components, specifically fatigue life, deformation, impact resistance, corrosion resistance, and brittle fracture, can all be significantly influenced by residual stresses. Accordingly, controlling the distribution of residual stresses is indeed important to protect the piece and avoid failure. Most of the previous works inspected the material properties, tool parameters, or cutting parameters, bu
... Show MoreSilver diamine fluoride (SDF) has shown effectiveness in hardening tooth structure and killing bacteria. Therefore, it can be used to prevent and arrest dental caries. Riva Star (SDF) treatment alone will stop cavities but will not reverse the cavitation. The Silver Modified Atraumatic Procedure, often known as Smart, is the optimum technique for regaining the tooth's structure and function. Glass ionomer was introduced in (1972) as a new material that has become one of the most widely used materials in restorative dentistry. By releasing fluoride ions, this material has a therapeutic impact on the surrounding tooth structure. Microleakage is the ingress of bacteria, its byproducts, toxins, chemicals, oral fluids, and ions between t
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