Background: This in vitro study measure and compare the effect of light curing tip distance on the depth of cure by measuring vickers microhardness value on two recently launched bulk fill resin based composites Tetric EvoCeram Bulk Fill and Surefil SDR Flow with 4 mm thickness in comparison to Filtek Z250 Universal Restorative with 2 mm thickness. In addition, measure and compare the bottom to top microhardness ratio with different light curing tip distances. Materials and Method: One hundred fifty composite specimens were obtained from two cylindrical plastic molds the first one for bulk fill composites (Tetric EvoCeram Bulk Fill and Surefil SDR Flow) with 4 mm diameter and 4 mm depth, the second one for Filtek Z250 Universal Restorative with 4 mm diameter and 2 mm depth. Each spcimen was light-cured using WOODPECKER LED CURING LIGHT for 20 sec. Polymerization was performed with the light tip positioned in direct contact, 2 mm, 4 mm, 6 mm and 8 mm distant from the top surface of the sample. After one day of storage in distilled water in a light proof container at 37ËšC, the hardness on the bottom and top surfaces of each specimen was tested using the Digital Micro Vickers Hardness Tester. Then the Data were analyzed statistically by ANOVA test, LSD test and t-test. Results: All experimental groups show top microhardness higher than bottom microhardness with high significant difference with all light tip distances. At 0 mm light tip distance all groups give the highest microhardness value. Filtek Z250 Universal Restorative shows accepted bottom to top microhardness ratio at all light tip distances. Surefil SDR Flow shows accepted bottom to top ratio only at 0, 2 and 4mm light tip distances while Tetric EvoCeram Bulk Fill shows the bottom to top microhardness ratio less than the accepted value with all light tip distances. Conclusion: From the results of this study we can conclude that the polymerization of bulk fill composite depends greatly on the distance from light curing tip, Tetric EvoCeram Bulk Fill composite not recommended to be used as bulk fill restoration in deep cavities and need further studies, while Surefil SDR Flow not recommended to be used in deep cavity when curing tip distance (6-8 mm), in addition we can conclude that the thickness of the increments is more important than light curing tip distance.
It has become necessary to change from a traditional system to an automated system in production processes, because it has high advantages. The most important of them is improving and increasing production. But there is still a need to improve and develop the work of these systems.
The objective of this work is to study time reduction by combining multiple sequences of operations into one process. To carry out this work, the pneumatic system is designed to decrease\ increase the time of the sequence that performs a pick and place process through optimizing the sequences based on the obstacle dimensions. Three axes are represented using pneumatic cylinders that move according to the sequence used. The system is implemented and con
... Show MoreThis work bases on encouraging a generous and conceivable estimation for modified an algorithm for vehicle travel times on a highway from the eliminated traffic information using set aside camera image groupings. The strategy for the assessment of vehicle travel times relies upon the distinctive verification of traffic state. The particular vehicle velocities are gotten from acknowledged vehicle positions in two persistent images by working out the distance covered all through elapsed past time doing mollification between the removed traffic flow data and cultivating a plan to unequivocally predict vehicle travel times. Erbil road data base is used to recognize road locales around road segments which are projected into the commended camera
... Show MoreBackground: Bilastine (BLA) is a second-generation H1 antihistamine used to treat allergic rhinoconjunctivitis. Because of its limited solubility, it falls under class II of the Biopharmaceutics Classification System (BSC). The solid dispersion (SD) approach significantly improves the solubility and dissolution rate of insoluble medicines. Objective: To improve BLA solubility and dissolution rate by formulating a solid dispersion in the form of effervescent granules. Methods: To create BLA SDs, polyvinylpyrrolidone (PVP K30) and poloxamer 188 (PLX188) were mixed in various ratios (1:5, 1:10, and 1:15) using the kneading technique. All formulations were evaluated based on percent yield, drug content, and saturation solubility. The fo
... Show MoreIn folk medicine there are various medicinal amalgamation possessing hepatoprotective activity. This activity is of significance because several toxins cause liver injury. Hence, many pharmaceutical companies are targeting herbal medicines for the treatment of liver abnormalities and towards evolving a safe and effective formulation with desired route of administration. In current review we have focused on the studies showing hepatoprotective effect using marine compounds and plant derived compounds. Liver disorder, a global health problem, usually include acute or chronic hepatitis, heptoses, and cirrhosis. It may be due to toxic chemicals and certain antibiotics. Uncontrolled consumption of alcohol also affects liver in an unhealthy wa
... Show MoreRecent advances in wireless communication systems have made use of OFDM technique to achieve high data rate transmission. The sensitivity to frequency offset between the carrier frequencies of the transmitter and the receiver is one of the major problems in OFDM systems. This frequency offset introduces inter-carrier interference in the OFDM symbol and then the BER performance reduced. In this paper a Multi-Orthogonal-Band MOB-OFDM system based on the Discrete Hartley Transform (DHT) is proposed to improve the BER performance. The OFDM spectrum is divided into equal sub-bands and the data is divided between these bands to form a local OFDM symbol in each sub-band using DHT. The global OFDM symbol is formed from all sub-bands together using
... Show MoreThe problem of frequency estimation of a single sinusoid observed in colored noise is addressed. Our estimator is based on the operation of the sinusoidal digital phase-locked loop (SDPLL) which carries the frequency information in its phase error after the noisy sinusoid has been acquired by the SDPLL. We show by computer simulations that this frequency estimator beats the Cramer-Rao bound (CRB) on the frequency error variance for moderate and high SNRs when the colored noise has a general low-pass filtered (LPF) characteristic, thereby outperforming, in terms of frequency error variance, several existing techniques some of which are, in addition, computationally demanding. Moreover, the present approach generalizes on existing work tha
... Show MoreThe auditor has a role in allocating joint costs in the gas industry, and the auditor's procedures are considered as systematic critical examination, analysis and evaluation of everything related to costs in general and joint costs in the gas industry in particular, with the aim of controlling the joint costs of gas industry products, and knowing the share of the cost of each product from the total industry costs Gas products reflect the reality of the company's performance by discovering weaknesses, defects and any errors, to ensure increased effectiveness and efficiency of the parties concerned with auditing them and imposing control and control over the company's resources, as well as
... Show Moreتعد المبارزة أحد الألعاب الرياضية التي يتأثر فيها الأداء بتطور القدرات الخاصة بالأداء ومنها تحمل (سرعة وقوة الأداء ),وأن أكثر الأساليب السابقة في تدريب تطوير تحمل(سرعة وقوة الأداء) بالمبارزة تكون على ارض صلبة مثل الخشب والألمنيوم آو الإسفلت وفي بعض القاعات يكون التارتان, وظل هذا الأسلوب لفترات طويلة في العراق ،حيث تستخدم تدريبات الإثقال التي تعمل على تنمية تحمل القوة . أما في الوقت الحاضر فقد ظهر اتجاه حديث في
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