EFFECT OF DIFFERENT IRRIGATION REGIMENS ON ENTEROCOCCUS FAECALIS ELIMINATION FROM INFECTED ROOT CANALS (AN IN-VITRO COMPARATIVE STUDY)

Microorganisms harbored in the complexities of root canal systems might lead to endodontic failures and development of apical periodontitis. Enterococcus faecalis is the most common isolated bacteria in these cases. Aim: This study was conducted to compare the efficiency of four irrigation regimens on the elimination of an inoculated strain of E. faecalis. Materials and Methods: Forty single rooted extracted premolars were inoculated with a standard strain of Enterococcus faecalis (ATCC 29212) and incubated at 37˚C for two weeks to allow infection of the dentinal tubules. The bacterial suspension was replaced with a new one every 48 hours. The teeth were then divided into four groups of n=10 each, to apply irrigation regimens as follows: Group i: irrigation with normal saline, Group ii: syringe irrigation (NaOCl 2.625%), Group iii: NaOCl 2.625%+EndoActivator and Group iv: NaOCl 2.625%+diode laser. Samples were collected at baseline and after irrigation. Colony-forming unit counts were performed. For baseline count of E. faecalis, differences in means between the groups were tested using the one way ANOVA F test. For the count of E. faecalis after the irrigation, differences in means was assessed using the Kruskal Wallis test. Results: The mean values of % of E. faecalis killed were respectively 99.2 ± 2.53% in group iv, 98.3± 5.34% in group iii, 29.0 ± 5.46% in group ii and 4.77 ± 0.78%) in group i. Conclusion: Maximum removal of E. faecalis strains was achieved by activating 2.625% sodium hypochlorite with the diode laser

Numerical Solution and Stability for Model of Extensible Beam

In this paper, numerical methods (finite differences methods for explicit and implicit) has been applied, to solve nonlinear partial differential equations. In methodology, the beam was divided into very smaller squares, then the study discussed three partial differential equations generating from model. The first equation called longitudinal vibrations of a beam, second equation known as transverse vibrations of a beam and then the third equation considered the extensible beam. The equation of extensible beam was defined by Woiniwsky- Krieger as a model for transverse deflection of an extensible beam of natural length. The study discussed the stability of these models (longitudinal vibrations, transverse vibrations and extensible beams). The stability solution has been counted and considered unconditionally for implicit method, but it's conditional for an explicit method. Obtaining the stability and convergent solution for longitudinal vibrations of a beam if width divisions is less than length divisions (

Vibration Signature of Roller Bearing’s Faults

Centrifugal pumps are widely used in many industrial applications. Defective pumps cause higher rate of energy loss with related overall performance degradation. Mechanical components fail due to decrease in pump’s strength or an increase in the force acting on it. Rolling bearings are one of the major components of the centrifugal pumps. Bearings are critical mechanical components in industrial machines. Bearing failure is often attributed to be one of the major causes of breakdown. Early detection of undesired conditions during the operation of the centrifugal pump has become very important in order to avoid consequential damages. Early detection is also vital for increasing availability and reliability. Automated health monitoring can reduce the outage time and repair costs. Using vibration analysis technique to monitor and evaluate the health of the machines has become an important technique in this field. In this research, we studied the vibration signatures of healthy and faulty conditions of the bearings of a pumping system. The pumping system consists of centrifugal pump and electrical motor. The vibration signatures analyze the bearing status with respect to the normal operation. The paper shows how to identify if there is a problem in the outer race of the Bearing Pass Frequency Outer Race (BPFO)

EL LENGUAJE JURÍDICO DEL DERECHO EGIPCIO DE FAMILIA (UN ENFOQUE DESCRIPTIVO)

The law number 100 for the year 1985 contains civil vocabulary that is irreligious and islamic vocabulary and terminology as well, which derives its principies from the al-Ŝarȋ'a al-Islâmiyya or islamic law.After analysing the islamic, english and french influences in the egyptian law, we have deducted that the current eyptian law «post occupation» is a mixed one, and it had a phase of transition that has not been ended yet.This mixed nature of the egyptian law sometimes and in sorne cases creates importants differences and opposites. Through this essay, we have described the main general principies and features for this unique language and which is really considered among the specialsing languages in the general arabic frame.Since the resources, references and analytic studies are rare for the legal arabic language law in general and the family law in particular; we think that the brief analysis which is represented in this essay can help those who are interested in this field and also the researchers.La Ley número 100 del año 1985 contiene un léxico positivo no religioso y otro léxico islámico religioso regido por los principios de al-Ŝarȋ'a al-Islâmiyya o el derecho islámico. Analizadas las influencias islámicas, francesas e inglesas en el derecho egipcio, hemos llegado a la conclusión de que actualmente el derecho egipcio pos-colonial es de una naturaleza híbrida y pasa por una etapa de transición que aún no ha finalizado. La naturaleza híbrida del derecho egipcio crea, en algunos casos, contradicciones importantes. A lo largo del presente artículo describiremos las directrices y aspectos generales de este lenguaje peculiar que no deja de ser de especialidad dentro de la lengua árabe general. Dada la escasez de bibliografía y estudios sobre el análisis del lenguaje jurídico árabe en general y del derecho de familia en particular, creemos que el breve análisis de este estudio podría ayudar a los interesados en este campo

Characterization of Asphalt Mixtures in Qatar

The State of Qatar went through a massive road construction program in the last decade as part of the ongoing development of its infrastructure and road transport network. Construction of roads in Qatar generally utilizes imported materials such as aggregate and binders as a result of the scarcity of local construction materials. Characteristics of asphalt mixtures are studied in this research program in order to evaluate mixtures properties in terms of aggregate packing, binder content, voids, mixture density, maximum density and Marshall Stability. Actual mixtures used in the Public Works Authority road projects were analyzed in the research program. Mixtures were prepared following the Qatar Construction Specifications (QCS, 2014). Combined aggregate gradations for different asphalt mixtures were compared with maximum density envelopes for different maximum aggregate sizes. Moreover, regression analysis was used to evaluate the strength of correlations established between different asphalt mixtures properties. The analysis of these mixtures is outlined in terms of general characteristics and consequently, recommendations are given to improve asphalt mixtures performance

Isothermal Transformation Temperatures and Its Effect in Hardiness of Pearlite Eutectic Steels R350HT Rails

يتميز الفولاذ المقاوم للصدأ  بعدد من الخواص الميكانيكية المرغوبة ، وبالتالي تمت دراسته على أنه بنية مجهرية مرشحة للسكك الحديدية المقواة برأس R350HT وفقًا لمعيار EN-13674. يدرس هذا العمل دور درجة حرارة التحويل لصف السكك الحديدية R350HT وتأثيرها على صلابة السكك الحديدية. تم الحصول على بنية الدقيقة المرغوبة تحت درجات حرارة تحويل  مختلفة. يتوافق تباين صلابة البرليت التي يتم الحصول عليها في ظل ظروف TTT مع التغيرات في تركيبها الداخيلي ودرجة حرارة التحول Abstract Fine pearlitic eutectic steel have a number of desirable mechanical properties and have thus been studied as candidate microstructure for R350HT head hardened rail according to EN-13674 standard. This work examines the role of transformation temperature of R350HT rail grade and their effect on rail hardiness. The fine pearlite structure has been obtained under different isothermal transformation temperatures. The variation of pearlite hardiness that obtained under TTT conditions conform to the changes in its structure and transformation temperature

Challenges for the Use of Local Materials in Unbound Road Subbase in Qatar

Current practice in Qatar is to blend local limestone with dune sand for use in unbound pavement applications. Dune sand is used to improve the properties of fine aggregate and compliance with the QCS 2014 requirements of plasticity and sand equivalent. The material has been successfully used for many years but currently facing the challenge of limited dune sand supply and recent government restrictions on its use in construction. The paper presents data on the properties of limestone obtained from different sources, tested in accordance with the QCS 2014 requirements. Variation of limestone source and the presence of clay particles greatly affected its suitability for use in unbound pavement applications. Improvement could be achieved by adjusting the grading of the material. Recommendations are made to revise the QCS 2014 specifications within the context of international specifications, when the unbound material is placed in a dry environment and away from the water level to enhance the wider utilization of local materials and sustainable construction in Qatar

PHYTOCHEMICAL STUDY OF BIOACTIVE CONSTITUENTS FROM SATUREJA MONTANA L. GROWING IN EGYPT AND THEIR ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES

 Objective: This work aimed to investigate the lipid constituents and flavonoidal compounds of Satureja montana, in addition to evaluation of different extracts and/or isolated compounds as antimicrobials and antioxidants.Methods: The volatile and lipid constituents were extracted with n-hexane by partition from hydroalcoholic extract of S. montana L. aerial parts, after then were fractionated to unsaponifiable matters and fatty acid methyl esters which were identified by gas–liquid chromatography and/or gas chromatography–mass spectrometry. The phenolic constituents were isolated from the ethyl acetate fraction of the aqueous methanolic extract of the aerial parts of the plant. The antimicrobial activity of different extracts and the isolated compounds was evaluated against Gram-positive, Gram-negative bacteria, yeast, and fungus using a modified Kirby-Bauer disc diffusion method.Results: The identified compounds are luteolin-7-rhamnoside-4'-O-β-glucopyranoside (1), quercetin-3-O-α-L-rhamnopyranoside (2), quercetin- 7-O-glucopyranoside (3), luteolin-7-O-glucopyranoside (4), 5-hydroxy-6,7,8,4'-tetramethoxy flavone (5), gallic acid (6), 2,3-hexahydroxydiphenoyl 1-galloyl glucopyranoside (7), and quercetin (8). The structure of all isolated compounds was established using different chromatographic and spectroscopic measurements (PC, thin-layer chromatography, ultraviolet [UV], 1D, 2D-nuclear magnetic resonance, and MS). Compound-2 showed the highest antibacterial activity against all the tested microorganisms. Hydroalcoholic extract exhibited high antioxidant activity (87.7%). On the other hand, hexane fraction showed a low antioxidant activity (46.4%), in addition to the compound-8 showed the highest antioxidant activity (96.27%) in 2,2-diphenyl-1-picrylhydrazyl assay.Conclusion: It can be concluded that the hydroalcoholic extract of S. montana showed significant antimicrobial and antioxidant activity

EXAMINING THE RELATIONSHIPS BETWEEN PERCEPTUAL LOAD PATTERNS, SELECTIVE ATTENTION AND VISUOSPATIAL WORKING MEMORY OF TWICE EXCEPTIONAL PUPILS WITH DYSCALCULIA OF PRIMARY STAGE

The research aims to examine the relationships between perceptual load patterns, selective attention and visuospatial working memory of twice exceptional pupils with dyscalculia of primary stage. The sample size consisted of 20 twice exceptional pupils with dyscalculia from sixth primary grade. The instruments were used for date collection: ordinary matrices test, prepared by Raven (1938); reading comprehension test, prepared by researcher; basic mathematical operations test, prepared by researcher; Bender gestalt test of motor visual disorder, prepared by Loretta Bendar (1938); Arabization by Fahmi, Ghoneim, Abu Al-Azayem Hospitalization (1990); quick survey form prepared by researcher; Wechsler 's Test of Children's Intelligence - Revised (1974), Arabization by Ismael and Malika (1999) ; selective attention task, prepared by researcher ;Computerized Verbal and Visual perceptual load pattern tasks (high-medium-low) prepared by researcher and Computerized Visuospatial working memory tasks (Pattern memory-Visual spatial sequencing) prepared by researcher. The date collected were analyzed by using the following statistical methods: frequency counts, percentages, Step-wise multiple regression analysis statistics, Z scores. The research concluded that perceptual load patterns, selective attention were very good predictors of visuospatial working memory of twice exceptional pupils with dyscalculia of primary stage.  Article visualizations