في الدراسة الحالية، تم تصنيع جسيمات ZrO2 النانوية باستخدام مستخلص نباتي مشتق من نبات Vitex agnus castus، ووسط قلوي مثل هيدروكسيد الصوديوم. تم استخدام أسلوب التخليق الحيوي لتحضير جزيئات أوكسيد الزركونيوم النانوية لهذا المشروع البحثي. تتميز هذه الطريقة عن غيرها بسبب فعاليتها من حيث التكلفة وبساطتها وقلة المخاطر المحتملة. وتم تشخيص العينات المحضرة باستخدام المجهر الإلكتروني النافذ TEM، المجهر الإلكتروني الماسح SEM، التحليل الطيفي بالأشعة تحت الحمراء بتحويل فورييه FT-IR، التحليل الطيفي فوق البنفسجي المرئي. ، حيود الأشعة السينية، والتحليل الطيفي للأشعة السينية المشتتة من الطاقة EDX. تم تحديد حجم البلورة باستخدام حيود الأشعة السينية من معادلة ديباي-شيرر بقيمة 26.37 نانومتر. تم استخدام المجهر الإلكتروني الماسح والمجهر الإلكتروني النافذ للتأكد من حجم جسيمات ZrO2 النانوية. في هذه الدراسة، أظهرت هذه الجسيمات النانوية مستويات متفاوتة من النشاط ضد نوعين من البكتيريا إيجابية الجرام ( Staphylococcus aurous و Streptococcus pneumonia)، ونوعين من البكتيريا السالبة الجرام (Proteus mirabilis و Escharia coli)، ونوع واحد من الفطريات وهو Candida. ومن المثير للاهتمام، أنه تم الكشف عن الإمكانات المضادة للسرطان لجسيمات أوكسيد الزركونيوم النانوية المركبة من خلال اختبار MTT بتركيز متنوعة لسرطان الرئة A549 من خط الخلية. وأظهرت نسبة التثبيط زيادة مع زيادة التركيز. إن حساب تثبيط نصف الخلايا IC50، والذي كان يساوي (58.4 ملغم/مل)، يشير إلى أن جزيئات أكسيد الزركونيوم النانوية لديها القدرة على الاستفادة منها في علاج السرطان
Three different types of nozzles (different wear rate) were used in this study. They are classified depending on the severity of their wear to three groups: new, worn and damaged nozzles. Those nozzles were spraying with the same application rate (303 l/ha) on two-year field trials; this was achieved by changing the spraying pressure for each group of nozzles in order to get the same application rate. This practice is usually done by operators of sprayers, who calibrate the sprayers on the same application rate every year without changing the nozzles, so they tend to reduce the spraying pressure in order to compensate the flow rate increase due to the nozzles yearly wear. Two types of
Background: One common undesirable side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization; the recent effort to improve the resistance against the demineralization is by the application of lasers. Materials and method: Thirty human premolars extracted for orthodontic purposes were used to test the effect of two energy level of ER-YAG laser on enamel resistance to demineralization. The brackets were bonded on the teeth and all the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. Three groups were generated. The fi
... Show MoreBackground: Controversy exists concerning the presence and amount of the Bennett mandibular immediate side shift among patients and whether it is necessary to accommodate for it in adjustable articulators. The aim of this study was to register and calculate the amount of any immediate side shift (ISS) present in patients requiring full mouth rehabilitation. Materials and methods: 3- dimensional condylar movements of 50 Iraqi TMD-free patients were recorded using a stereographic fully adjustable articulator system during protrusion, left and right eccentric mandibular movements. Protrusive angles of each patient were verified to figure out the suitable fossa analog for each case. The thickness of each right and left premade fossa analog sele
... Show MoreAnumerical solutions is presented to investigate the effect of inclination angle (θ) , perforation ratio (m) and wall temperature of the plate (Tw) on the heat transfer in natural convection from isothermal square flat plate up surface heated (with and without concentrated hole). The flat plate with dimensions of (128 mm) length × (64 mm) width has been used five with square models of the flat plate that gave a rectangular perforation of (m=0.03, 0.06, 0.13, 0.25, 0.5). The values of angle of inclination were (0o, 15o 30o 45o 60o) from horizontal position and the values of wall temperature (50oC, 60 oC, 70 oC, 90 oC, 100o<
... Show MoreThis study was conducted in the Department of Employment and Loans at the Ministry of Labor and Social Affairs to indicate the importance and impact of both the empowerment and the functional flexibility in evaluating the performance of the employees. To achieve the objectives of the study, the data was collected through a questionnaire form designed for this purpose based on previous studies. Data obtained for a significant evaluation of the relationship between the components of both the empowerment and the functional flexibility with the components of the evaluation and determining the degree of importance of each component of both the empowerment and functional flexibility for the components of the evaluation by the extractio
... Show MoreExperimental 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.
Pablo Neruda's artistic distinctiveness can be considered in two ideas or attitudes of romanticism. First, the imagination, which is the result of conduct and spirituality, and second, the individualism, which is a collection of mysterious mysteries from the texts of individuality based on philosophical sonnets. His collection of poems points out the ethereality and indescribability of life, employing the reality of life at the level of human perception in a symbolic language. In other words, Pablo Neruda recreates the meanings in poetry through the three ideas of reduction, interpretation, and analysis. "What is the essential connection between individualism and the symbolic language of Pablo Neruda's imagination and What are the reason
... Show MoreThis study focuses on studying an oscillation of a second-order delay differential equation. Start work, the equation is introduced here with adequate provisions. All the previous is braced by theorems and examplesthat interpret the applicability and the firmness of the acquired provisions