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The paper is investigated the application of compressed natural gas (CNG) as an alternative fuel and its performance effect in the diesel engines using GT-POWER computational simulation. The CNG as an alternative fuel for four stroke diesel engine modeling was developed from the real diesel engine using GT-POWER computational model with measure all of engine components size. The computational model will be running on mono CNG fuel and mono diesel fuel to simulate and investigate the engine performance effect on the difference fuel. Output of the model simulation shown the effect of diesel engine fueled by CNG performance effect were simulated in any engine speeds parameters. Keywords: Comparative performance, compressed natural gas, diesel engines, simulation, INTRODUCTION In the diesel engines, the details of the diesel engine design vary significantly over the engine performance and size range. In particular, different combustion chamber geometries and fuel injection [...]

Introduction: Periodontal diseases are among the most common chronic disorders that have plagued humans for centuries and it is affected by social, economic and other factors. Periodontal diseases were more severe among patients with developmental disability. Objectives: to determine the prevalence of periodontal diseases among special needs children of schools of Kota Bharu in Kelantan, Malaysia and to determine the relationship between periodontal status and sociodemographic factors among these children. Methodology: Participants were examined for periodontal status by CPI. Questionnaires requesting sociodemographic information were distributed to all participants. Results: About 52.9% of children had calculus and 33.9% had gingival bleeding. There was association between prevalence of periodontal disease with age. There were no associations with other socio demographic factors. Conclusion: The periodontal disease prevalence was high 86.8% while the percentage of those with healthy periodontal condition was only 13.2%. There was association between prevalence of periodontal diseases and age. [ABSTRACT FROM AUTHOR]

The natural gas is a promising alternative fuel which fulfills the strict engine emission regulations in many countries. In a compressed form, known as CNG (compressed natural gas) has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. This is equipped with the engine conversion technology which is well established and the availability of the conversion equipment. For spark ignition engines there are two options, a bi-fuel conversion and a dedicated to CNG engine. For compression ignition engines converted to run on natural gas, there are two main options discussed, dual-fuel engines and normal ignition. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the CNG engines research and the development of CNG as fuel used are highlighted to keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. The high activities for future CNG engines research and development to meet future CNG engines is recorded in the paper. [ABSTRACT FROM AUTHOR]

Introduction: This in-vitro study compared the adhesive remnant index (ARI). Percentage using image analyzer after the removal of stainless steel brackets bonded with self-etching primer (SEP) and adhesive but cured using two different types of light: light emitting diode (LED) and Tungsten-Quartz-Halogen (TQH) light. Materials and Methods: Fifty extracted human premolar teeth were divided into two groups. In group I, 25 teeth were etched with Transbond Plus XT 3M-Unitek SEP and stainless steel brackets were bonded using Transbond XT 3M-Unitek Adhesive and cured with LED (Ortholux LED 3M-Unitek) for 10 seconds according to manufacturer instruction. In group II, 25 teeth were etched with the same Transbond Plus XT 3M-Unitek SEP and the same types of brackets were bonded using Transbond XT 3M-Unitek Adhesive but cured with TQH light (Ortholux XT 3M-Unitek) for 20 seconds according to manufacturer instruction. Brackets were removed using the Instron machine and enamel surfaces were photographed with the Image Analyzer System including the digital camera (Leica, Germany). The software measured the area of residual resin on enamel surfaces and the ARI percentages were calculated. Results: ARI of both groups after bracket removal using the same type of primer and adhesive but different type of curing light showed significant differences (p = 0.04). Conclusion: Brackets cured with LED produced more adhesive remnant than brackets cured with TQH. More adhesive remnant might be of advantage as it may reduce destruction of the enamel after bracket removal. Moreover, LED has a shorter curing time (10 seconds) which is time saving and economical. [ABSTRACT FROM AUTHOR]