Experimental work has been performed on three capillary tubes of different lengths and diameters using R-12 and R-134a. The test also studies the effect of discharge and speed of evaporator fan. The results clearly showed that refrigerant type and discharge significantly influence the temperature drop across the capillary tube. While the speed of evaporator fan has small effect. Experimental results showed that the temperature gradient for the two refrigerants are the same, but after approximatly one meter the temperature gradient of R-134a is steeper than R-12.
Photorefractive keratectomy (PRK) is the refractive technique that began with a physical scraping of the epithelial layer of cornea subsequent by laser treatment. Post this procedure to about 48 hours the removed epithelial layer regenerated to protect the eye again. The regeneration process (called re-epithelization) started from the limbus of the cornea toward the central part of it. The re-epithelization mechanism consists of a change in cell density (mitosis) and cell concentration (migration) with a velocity in two directions: radial and tangential. In the present study, an estimation for both radial (responsible for the overlapped layers toward the outward direction of the cornea) and tangential comp
... Show MoreThe purpose of this work was to study the effects of the Nd:YAG laser on exposed dentinal
tubules of human extracted teeth using a scanning electron microscope (SEM). Eighty 2.5mm-thick
slices were cut at the cementoenamel junction from 20 extracted human teeth with an electric saw. A
diamond bur was used to remove the cementum layer to expose the dentinal tubules. Each slice was
sectioned into four equal quadrants and the specimens were randomly divided into four groups (A to D ).
Groups B to D were lased for 2 mins using an Nd:YAG laser at 6 pulses per second at energy outputs of
80 , 100 and 120 mJ. Group A served as control. Under SEM observation, nonlased specimens showed
numerous exposed dentinal tubules. SEM o
It is the grace of God and his grace that he accepts repentance for his slaves, forgives their bad deeds in return for their misfortune, or offers them a good deed, but pardons many of them for free. Therefore, it is not long for God Almighty to forgive His mercy for many of His slaves and bring them to Paradise with no punishment or punishment, even if they have committed some sins, because of the multitude of their favorable navigational disadvantages, or even without gratitude thanks to him and him. With all this, some have overlooked the old and new on these things and amazed at the hadeeth ((God may have seen the people of the full moon and said do what you want, I have forgiven you)). Therefore, the scholars tried to answer some of
... Show MoreThis study deals with the field of acieving the manuscripts of Islamic sciences by the great Imam ibn Kamal Pasha, but the mentioned book requires a great effort to explain what it contains of sciences, and to appear what it has contained
،يريغت وأ ةلكشم وأ ةثداح ةجيتن ،ةعمالجا وأ درفلا هذختي فقوم هرهوج في ماعلا يأرلا دعي ةيوبرت تماكارتو ،ةيرثك تانوكم لىع هسسأ في موقي وهف اذل ،ةشاعلما ةايلحا تاقايس في لصيح فيو ،عمتمج يلأ يعماتجلاا لعفلا ةيصوصخ تاقايس بسحب يرسي ايرطف نوكي ام اهنم ،ةيفاقثو يعولا ةلاح تيبثت ديرت تاهج نم ةلعتفمو ةعنطصم تايطعمب اهيريست وأ اهذحش متي ىرخأ نايحأ ليكشت ةيلمع تنترقا ذل ،ةثدالحا كلت مهف ةأطو ليلقت وأ يريغت وأ فرح وأ ي
... Show MoreThis research reviews the basis for the settlement of claims when marine losses occur, including the settlement of claims in the case of joint maritime losses for goods and ship objects, as well as the settlement of claims for damage to vessel objects when they are at sea risk and loss during the sea voyage. Construction
The Research used descriptive, analytical and historical methods in preparing the research; the society of study composed of the employee in the insurance companies working in Sudan, the questionnaire was distributed for all study samples. The study concluded some important results of which it is , there is a weak of awareness, and lack of
... Show MoreExperimental investigations had been done in this study to demonstrate the effect of natural particles used as a reinforcement material to unsaturated polyester resin. The tensile test and water absorption were investigated according to (ASTM D638) and (ASTM D570), respectively. The influence of sunflower husk and pomegranate husk particles, used as a reinforcement material, on the tensile strength, Young's modulus and water absorption with different weight fraction (3%, 7% and 10%) and particle grain size (50µm, 100 µm and 150 µm), has been investigated. The water absorption of polymer composites was studied by measuring the specimen weight before and after immersion in water for one hundred days. In the experiments of tensile test,
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Mixed convection heat transfer to air inside an enclosure is investigated experimentally. The bottom wall of the enclosure is maintained at higher temperature than that of the top wall which keeps in oscillation motion, whereas the left and right walls are well insulated. The differential temperature of the bottom and top walls changed several times in order to accurately characterize the temperature distribution over a considerable range of Richardson number. Adjustable aspect ratio box was built as a test rig to determine the effects of Richardson number and aspect ratio on the flow behavior of the air inside the enclosure. The flow fields and the average Nusselt number profiles were presented in this wo
... Show MoreUrinary tract infections (UTIs) mean microbial pathogens in the urethra or bladder (lower urinary tract). Important risk factors for recurrent UTI include obstruction of the urinary tract, use of a bladder catheter or a suppressed immune system. This study aims to isolate and identify bacteria from patients with TCC-bladder cancer or patients with a negative cystoscope and estimate antibiotic susceptibility patterns and evaluate some of the virulence factors. From a total of 62 patients with TCC-BC or negative cystoscope, only 35 favorable bacterial growths were obtained, including Escherichia coli (UPEC), a significant bacterial isolate, and Stenotrophomonas maltophilia. The percentage of multi drug-resistance bacteria
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