A mathematical model has been formulated to predict the influence of high outdoor air temperature on the performance of small scale air - conditioning system using R22 and alternative refrigerants R290, R407C, R410A. All refrigerants were investigated in the cooling mode operation. The mathematical model results have been validated with experimental data extracted from split type air conditioner of 2 TR capacity. This entailed the construction of an experimental test rig which consists of four main parts. They are, the refrigeration system, psychrometric test facility, measuring instrumentation, and auxiliary systems. The conditioned air was maintained at 25 0C dry bulb and 19 0C wet bulb for all tests. The outdoor ambient air temperature was varied from 35 0C to 55 0C in 5 0C increments. The study showed that R290 is the better replacement for R22 when the air conditioning system works under high ambient temperature. It has better performance as a drop in refrigerant. R407C has the closest performance to R22, followed by R410A.
Catalytic reduction is considered an effective approach for the reduction of toxic organic pollutants from the environment, but finding an active catalyst is still a big challenge. Herein, Ag decorated CeO2 catalyst was synthesized through polyol reduction method and applied for catalytic reduction (conversion) of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The Ag decorated CeO2 catalyst displayed an outstanding reduction activity with 99% conversion of 4-NP in 5 min with a 0.61 min−1 reaction rate (k). A number of structural characterization techniques were executed to investigate the influence of Ag on CeO2 and its effect on the catalytic conversion of 4-NP. The outstanding catalytic performances of the Ag-CeO2 catalyst can be assigne
... Show MoreExcessive water production is a persistent challenge in oil and gas wells, with polymer and gel solutions commonly employed for water control. This study investigates the rheological behaviour of cross-linked polyacrylamide gels and their impact on water shutoff treatment in gas wells. Rheological measurements, coreflooding experiments using Berea sandstone samples, and micromodel flow visualizations were conducted to evaluate gel performance. Results showed that during water injection, the water residual resistance factor ( Frrw ) decreases with increasing flow rates, mainly due to gel shear thinning behaviour and reduced residual gas saturation. Higher polymer concentrations in the gel enhance water permeability reduction. In contrast, un
... Show MoreThis paper presents a novel inverse kinematics solution for robotic arm based on artificial neural network (ANN) architecture. The motion of robotic arm is controlled by the kinematics of ANN. A new artificial neural network approach for inverse kinematics is proposed. The novelty of the proposed ANN is the inclusion of the feedback of current joint angles configuration of robotic arm as well as the desired position and orientation in the input pattern of neural network, while the traditional ANN has only the desired position and orientation of the end effector in the input pattern of neural network. In this paper, a six DOF Denso robotic arm with a gripper is controlled by ANN. The comprehensive experimental results proved the appl
... Show MoreUnderstanding how abiotic influences affect organisms and their interactions within ecological communities has long been of interest to ecologists. The significance of this comprehension has increased given rapid human-induced climate change. Wind speed variation is one of the less researched effects of climate change, as wind speeds worldwide are generally falling. Although wind is a fairly universal component of the environment, relatively little work has been conducted to integrate our knowledge of how wind affects interactions between different species. In this study, the influence of wind on bottom-up trophic interactions in the plant–ungulate–wolf food chain has been investigated through mathematical modeling. Positivity and bound
... Show MoreFatty acids, particularly omega-3, omega-6, and omega-9, play a vital role in various biological processes. As the body cannot synthesize omega-3 and omega-6, dietary sources of these fatty acids are essential. Each omega fatty acid has a distinct chemical structure, source, and function. Cisplatin (CP) treatment is known to cause acute kidney injury (AKI) due to its inflammatory effects. This study explored the renoprotective potential of omega-3-6-9 when co-ad-ministered with cisplatin in a mice model. We divided adult mice into five groups: a control group received 0.5 ml of liquid paraffin; a cisplatin-only group; two groups were treated with low (50 mg/kg) and high (100 mg/kg) doses of omega-3-6-9 plus cisplatin; and a final group rece
... Show MoreCranberry (Vaccinium macrocarpon) is a North American natural fruit. consumed as food and used for health promotion and prevention of various diseases. Aim. The present study was designed to evaluate the protective effect of cranberry fruit extract on nephrotoxicity induced by cisplatin in mice by measuring selected oxidative stress markers. Methods. Twenty-eight male albino mice were used in this study. The animals were divided into 4 groups as follows: Group I [Negative Control]/orally-administered normal saline for 7 successive days; Group II [Orally-administered cranberry fruit extract alone (200 mg/kg) for 7 successive days; Group III/Mice IP injection with cisplatin (12mg/kg) on day 7 and; Group IV [Orally-administered cr
... Show MoreDoxorubicin (DOX) is an efficient antineoplastic agent with a broad antitumor spectrum; however, doxorubicin-associated cardiotoxic adverse effect through oxidative damage and apoptosis limits its clinical application. Cafestol (Caf) is a naturally occurring diterpene in unfiltered coffee with unique antioxidant, antimutagenic, and anti-inflammatory activities by activating the Nrf2 pathway. The present study aimed to investigate the potential chemoprotective effect of cafestol on DOX-induced cardiotoxicity in rats. Wistar albino rats of both sexes were administered cafestol (5 mg/kg/day) for 14 consecutive days by oral gavage alone or with doxorubicin which was injected as a single dose (15 mg/kg intraperitoneally at day 14) to i
... Show MoreIn most manufacturing processes, and in spite of statistical control, several process capability indices refer to non conformance of the true mean (µc ) from the target mean ( µT ), and the variation is also high. In this paper, data have been analyzed and studied for a blow molded plastic product (Zahi Bottle) (ZB). WinQSB software was used to facilitate the statistical process control, and process capability analysis and some of capability indices. The relationship between different process capability indices and the true mean of the process were represented, and then with the standard deviation (σ ), of achievement of process capability value that can reduce the standard deviation value and improve production out of theoretical con
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