The electrospun nanofibers membranes (ENMs) have gained great attention due to their superior performance. However, the low mechanical strength of ENMs, such as the rigidity and low strength, limits their applications in many aspects which need adequate strength, such as water filtration. This work investigates the impact of electrospinning parameters on the properties of ENMs fabricated from polyacrylonitrile (PAN) solved in N, N-Dimethylformamide (DMF). The studied electrospinning parameters were polymer concentration, solution flow rate, collector rotating speed, and the distance between the needle and collector. The fabricated ENMs were characterized using scanning electron microscopy (SEM) to understand the surface morphology and es

Background: Recently, Poly propylene fibers with and without plasma treatment have been used to reinforce heat cure denture base acrylic but, so far some of properties like tensile strength , wettability and wear resistance not evaluated yet, the aim of the study is to clarify the influence of incorporation of treated and untreated fibers on these properties. Materials and methods: Twenty one specimens were fabricated for every tested property(tensile strength, wear resistance and wettability) that classified into three groups(control, untreated poly propylene fibers reinforced specimens and Oxygen plasma treated group)and for each test sevens amples were used(n=7). Tensile strength was tested using Instron universal testing machine, wear

In this research, geopolymer mortar had to be designed with 50% to 50% slag and fly ash with and without 1% micro steel fiber at curing temperature of 240℃. The molarity of alkaline solution adjusted with 12 molar sodium hydroxid to sodium silicate was 2 to 1, reaspectivly. The heat of curing increased the geopolymerization proceses of geoplymer mortar, which led to increasing strength, giving the best result and early curing age. The heat was applied for two days by four hours each day. It was discovered in the impact test that the value first crack of each mix was somewhat similar, but the failure increased 72%  for the mixture that did not contain fiber. For the energy observation results it was shown that the mixt

The phenomenon of negative behavior has studied as a social and psychological phenomenon that effect on the performance and life of workers inside and outside the organization. The adoption of this phenomenon is studied in terms of the role of the internal environment of the organization in addressing this behavior, being the variables belong to the field of organizational behavior to see the results of those variables on the Iraqi organizations, since the specificities of it differ from the rest of the Arab and foreign environments. Therefore, this study focused on testing the relationship of the internal environment of the organization and its role in addressing the negative behavior of the workers.

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In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation condition

Heat pipes and two‐phase thermosyphon systems are passive heat transfer systems that employ a two‐phase cycle of a working fluid within a completely sealed system. Consequently, heat exchangers based on heat pipes have low thermal resistance and high effective thermal conductivity, which can reach up to the order of (105 W/(m K)). In energy recovery systems where the two streams should be unmixed, such as airconditioning systems of biological laboratories and operating rooms in hospitals, heat pipe heat exchangers (HPHEs) are recommended. In this study, an experimental and theoretical study was carried out on the thermal performance of an air‐to‐air HPHE filled with two refrigerants as working fluids, R22 and R407c. The heat pipe he

The surface finish of the machining part is the mostly important characteristics of products quality and its indispensable customers’ requirement. Taguchi robust parameters designs for optimizing for surface finish in turning of 7025 AL-Alloy using carbide cutting tool has been utilized in this paper. Three machining variables namely; the machining speeds (1600, 1900, and 2200) rpm, depth of cut (0.25, 0.50, 0.75) mm and the feed rates (0.12, 0.18, 0.24) mm/min utilized in the experiments. The other variables were considered as constants. The mean surface finish was utilized as a measuring of surface quality. The results clarified that increasing the speeds reduce the surface roughness, while it rises with increasing the depths and fee

In this research, we sought to identify the nature of the relationship between the exchange rate of the Chinese yuan and the value of Chinese exports, through the formulation of a standard model based on the model of common integration, and based on the data of the study and using the test "Angel-Granger" It reflects the relationship between the two research variables, through which the relationship between the RMB exchange rate and the value of Chinese exports was estimated during the period 1978-2017.

This research aims to investigate the effect of four types of nanomaterial on the Marshall properties and durability of warm mix asphalt (WMA). These types are; nano silica(NS), nano carbonate calcium (NCC), nano clay(NC), and nanoplatelets (NP). For each type of Nanomaterial, three contents are tried as following; NS(1%, 3%, and 5%), NCC(2%, 4%, and 6%), NC(3%, 5%, and 7%), and NP (2%, 4%, and 6%) by weight of asphalt cement. Following Marhsall mix design method, the optimum asphalt cement content is determined, thereafter the optimum dosage for each nanomaterial is obtained based on the highest Marshall stability value. The durability of the control mix (no nanomaterial) and modified mixtures have been compared based on moisture damage, r

Strategy Descrtibes How an Organization Matches its own Capabilites With Opportunities in Environment , in Order to Accomplish its Overall Objectives , So That The Organization is Considering Responding to Challenges by Adopting one or More of Strategies, Like Differentioning its Product, or Achieving Cost Leadership.

The Key Role of Management Accountant is to Evlaute The Successful it Has Been in Implementing Organization Strategy.

This Research Target to Explain The Key Role of Management Accountant in Evaluate of  Organization Strategy. by Strategic Analysis of Operating Income From Specific Sources Such as Cost Savings and Growth in Stead of Emphasizing Only The Aggrega