Background: Alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. The contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. The objective of this study is to evaluate the impact of various contact time intervals of Alginate impressions & type III dental stone on surface properties of stone cast. Materials and Methods: Time intervals tested were 1hour, 6 hours and 9 hours. Surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. Surface detail reproduction was determined using cylindrical brass test block in accordance with ISO 1563. Surface roughness was measured by profilometer and hardness was measured by Durometer (Shore D). Results: The detail reproduction showed significant difference (P<0.05), at 6 hr., and 9 hr. showed better results. While surface roughness significantly decreased (p<0.01) with prolonged contact time. However, surface hardness increased significantly (p<0.01) with increased contact time. Conclusions: Surface detail reproduction increased with increasing the contact time and this was noticed at (6, 9 hours). However, 1hour time interval showed decreased surface detailed reproduction. Roughness decreased when the contact time was increased between type III dental stone and alginate impression whereas, hardness was improved significantly with increasing contact time.
In the city of Hebron, small business industrial organizations face a major challenge related to its ability to reach, attract and sustain a sufficient number of customers in order to ensure its continuity and sustainability. The research problem is summarized in an attempt to reveal how the e-marketing could improve and support the marketing effectiveness of small business industrial organizations in the city of Hebron/Palestine. The importance of this research stems from the fact that it addresses a new knowledge branch of the field of marketing, which is electronic marketing for small business organizations, and the fact that the research highlights appropriate marketing solutions for these organizations in light of the Intern
... Show MoreThe present study explores numerically the energy storage and energy regeneration during Melting and Solidification processes in Phase Change Materials (PCM) used in Latent Heat Thermal Energy Storage (LHTES) systems. Transient two-dimensional (2-D) conduction heat transfer equations with phase change have been solved utilizing the Explicit Finite Difference Method (FDM) and Grid Generation technique. A Fortran computer program was built to solve the problem. The study included four different Paraffin's. The effects of container geometrical shape, which included cylindrical and square sections of the same volume and heat transfer area, the container volume or mass of PCM, variation of mass flow rate of heat transfer fluid (HTF), and temp
... Show MoreIn this paper waste natural material (date seed) and polymer particles(UF) were used for investigation of removal dye of the potassium permanganate. Also study effect some variables such as pH, dye concentration and adsorbent concentration on dye removal. 15 experimental runs were done using the itemized conditions designed established on the Box-Wilson design employed to optimize dye removal. The optimum conditions for the dye removal were found: (pH) 12, (dye con.) 2.38 ppm, (adsorbant con.) 0.0816 gm for date seed with 95.22% removal and for UF (pH) 12, (dye con.) 18 ppm, (adsorbant con.) 0.2235 gm with 91.43%. The value of R-square was 85.47% for Date seed and (88.77%) for UF.
... Show More
Atenolol is one of beta-adrenergic receptor blocking agent. It is widely used for the treatment of hypertension as a selective antihypertensive drug. But long term usage of atenolol may cause one of the cardiovascular diseases like myocardial infarction. To prove the relationship between atenolol and cardiovascular disease, measurement of creatinekinase-MB as a diagnostic indicator in early and long term usage of this drug by hypertensive patients is recommended. A comparative study was conducted in Al-Yarmouk Teaching Hospital–Emergency Department- on 30 hypertensive patients using atenolol. They were divided into (2) groups A and B according to the duration of the drug usage. Group A- (15) patients with a mean age (56
... Show MoreIn this work, a convex lens concentrating solar collector is designed and manufactured locally by using 10 convex lenses (concentrator) of a diameter 10cm and one Copper absorber tube of a diameter 12.5mm and 1mm in thickness 1m length. Two axes manual Tracking system also constructed to track the sun continuously in two directions. The experiments are made on 17th of May 2015 in climatic conditions of Baghdad. The experimental data are fed to a computer program to solve the thermal performing equation, to find efficiency and actual useful energy. Then this data is used in numerical CFD software for three different absorber diameters (12.5 mm, 18.75 mm and 25 mm). From the results that obtained the maximum the
... Show MoreIn this study, gold nanoparticles (AuNPs) were synthesized using a plasma jet system at different exposure times. Using ultraviolet, visible spectra, X-ray diffraction, the nanoparticles were characterized (XRD). A Plasmon surface resonance concentrated at 530, 540, and 533 nm for the prepared AuNPs. The pattern of XRD showed that the extreme peaks of the film reflect crystalline existence. The face-centered cubic structure of the gold nanoparticles was prepared for all samples, with an average crystallite size of 25-40 nm. The effect of AuNPs in vivo on liver function levels was measured. For all doses, we notice an increase in the ranks of liver function in the blood during the period of dosing, and it begins to decrease when the dosi
... Show Moreتتمثل مشكلة الدراسة في الصعوبات التي يواجهها طلاب اللغة الإنجليزية كلغة أجنبية في تعلم وإتقان المتلازمات اللفظية. تهدف هذا الدراسة تهدف إلى تحديد أثر استخدام تقنية المسرد الاملائي على معرفة المتلازمات اللفظية لدى الطلاب. ولتحقيق أهداف هذا البحث والتحقق من فرضياته تم اختيار عينة عشوائية مكونة من (60) طالبة من كلية اللغة الإنجليزية للسنة الثانية باستخدام كتاب الفهم القرائي المقرر للمستوى الثاني في قسم الل
... Show MoreBackground: Inhalation therapy has been employed as the mainstay of the treatment in chronic respiratory diseases such as asthma, Patients who taking asthma medication may be at risk of many health problems including oral health .The purpose of this study was to assess the local effect of ICS on oral tissue by measuring Candida albicans count colonies in saliva among12 years old asthmatic children who were collected from AL- Zahra Center Advisory for Allergy and Asthma, and compares them with non asthmatic children of the same age and gender. Material and Methods: The total sample involved sixty children of 12 years old, thirty asthmatic children who received medium dose of ICS/day (200-400 microgram/day) for 2 years and 30 non-asthmatic ch
... Show More