Thermal performance of closed wet cooling tower has been investigated experimentally and theoretically
in this work. The theoretical model based on heat and mass transfer equations and heat and mass transfer balance equations which are established for steady state case. A new small indirect cooling tower was used for conducting experiments. The cooling capacity of cooling tower is 1 kW for an inlet water temperature of 38oC, a water mass velocity 2.3 kg/m2.s and an air wet bulb temperature of 26oC. This study investigates the relationship between saturation efficiency, cooling capacity and coefficient of performance of closed wet cooling tower versus different operating parameters such wet-bulb temperature, variable air-spray water flow ratio and cooling water inlet temperature. Results indicate that the capacity and saturation efficiency was found close to the related experimental results. Good agreement was obtained between the theoretical results and experimental measurements for the performance of small cooling tower.
In this work, optical system with different aperture shapes (circular, square, elliptical and triangle aperture) has been used for efficiency evaluation when the system involved moving factor in ideal case (aberration free). The optical system evaluate far moving object, therefore the image forming at image plane due to point spread function (image formula of incoherently illuminated point object). A mathematical treatment has been used to getting results by Gaussian numerical calculations method. The results show priority of circular aperture when optical system that submits of moving factor.
Abstract:
The aim of this research is to highlight the importance of achieving customer satisfaction by using information technology and Internet networks in the process of purchasing flight tickets, and switching from the traditional method of purchasing and payment operations to the electronic method, to reduce the financial and non-financial risks associated with the traditional purchasing process, as well as saving time, effort and costs for the customer. The researcher used the deductive approach in linking the variables (achieving customer satisfaction and Internet of Things technology for booking electronic tickets)
... Show MoreIn recent years, there has been a significant increase in research demonstrating the new and diverse uses of non-thermal food processing technologies, including more efficient mixing and blending processes, faster energy and mass transfer, lower temperature and selective extraction, reduced thermal and concentration gradients, reduced equipment size, faster response to extraction control, faster start-up, increased production, and a reduction in the number of steps in preparation and processing. Applications of ultrasound technology have indicated that this technology has a promising and significant future in the food industry and preservation, and there is a wide scope for its use due to the higher purity of final products and the
... Show MoreReintervention after balloon angioplasty is often considered inevitable in children with coarctation of the aorta (COA). The present study aimed to evaluate predictors of re-intervention after balloon angioplasty for COA, with the goal of identifying patient and procedural characteristics that may influence long-term outcomes
Electronic learning was used as a substitute method for learning during the COVID-19 pandemic to conduct scientific materials and perform student assessment; this study aimed to investigate academic staff opinions toward electronic education. A cross-sectional study with a web-based questionnaire distributed to academic staff in different medical colleges in Iraq. After de-identification, data were collected and analyzed with statistical software to determine the significance between variables. A total of 256 participants were enrolled in the study: 83% were not satisfied or neutral to online learning, 80% showed a poor benefit from delivery of the practical electronic knowledge and 25% for theoretical sessions with a significant difference
... Show MoreIn this research, some robust non-parametric methods were used to estimate the semi-parametric regression model, and then these methods were compared using the MSE comparison criterion, different sample sizes, levels of variance, pollution rates, and three different models were used. These methods are S-LLS S-Estimation -local smoothing, (M-LLS)M- Estimation -local smoothing, (S-NW) S-Estimation-NadaryaWatson Smoothing, and (M-NW) M-Estimation-Nadarya-Watson Smoothing.
The results in the first model proved that the (S-LLS) method was the best in the case of large sample sizes, and small sample sizes showed that the
... Show MoreBackground: Gugglusterone has been reported to provide protection against inflammatory and oxidative reactions of different pathological conditions. Objectives: The main object of this research work is to evaluate the renoprotective effects of guggulsterone in the prevention of cisplatin-induced nephrotoxicity in rats via assessment of renal function and histological study. Materials and methods: Rats in this study were split into four groups which comprise a control group, an induction group, a third group receiving low-dose guggulsterone, and a fourth group receiving high-dose guggulsterone. Results: a single dose of cisplatin drug has jeopardisedrenal physiology that has been demonstrated in histopathology sections and elevation
... Show MoreOne of the most important enhanced oil recoveries methods is miscible displacement. During this method preferably access to the conditions of miscibility to improve the extraction process and the most important factor in these conditions is miscibility pressure. This study focused on establishing a suitable correlation to calculate the minimum miscibility pressure (MMP) required for injecting hydrocarbon gases into southern Iraq oil reservoir. MMPs were estimated for thirty oil samples from southern Iraqi oil fields by using modified Peng and Robinson equation of state. The obtained PVT reports properties were used for tunning the equation of state parameters by making a match between the equation of state results with experimenta
... Show MoreThe Hubble telescope is characterized by the accuracy of the image formed in it, as a result of the fact that the surrounding environment is free of optical pollutants. Such as atmospheric gases and dust, in addition to light pollution emanating from industrial and natural light sources on the earth's surface. The Hubble telescope has a relatively large objective lens that provides appropriate light to enter the telescope to get a good image. Because of the nature of astronomical observation, which requires sufficient light intensity emanating from celestial objects (galaxies, stars, planets, etc.). The Hubble telescope is classified as type of the Cassegrain reflecting telescopes, which gives it the advantage of eliminating chromat
... Show MoreThe Diwan of Imam Al-Shafi’i acquires great importance, as Al-Shafi’i is an authority in the language, and when I saw that no one had preceded me in exploring its depths, I took my tool and turned my face towards it intending to study the triple verb in it. I stop at these verbs and the student pauses for their morphological forms, looking at the significance of the triple verb more with one letter, two letters, and three letters, and I found that they are many, and such research cannot contain them all, so the choice came to choose the triple verb more with one letter, and the significance of the increase in it, as the increase in The building necessitates an increase in the meaning, and from here the study was limited to the triple
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