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Low temperature combustion (LTC) strategies have the potential for simultaneous reduction in oxides of nitrogen (NOx) and soot emissions while achieving higher thermal efficiency. Commercial widespread implementation of LTC strategies demands addressing several challenges, including narrow operating load range, lack of ignition timing control, and reducing high unburned hydrocarbon (HC) and carbon monoxide (CO) emissions. These challenges could be because the conventional engine design and fuels cannot adapt well to LTC modes. Thus, replacing conventional diesel fuel with suitable alternative fuels for LTC strategies is essential. In the present work, three LTC strategies, Homogenous Charge Compression Ignition (HCCI), Premixed Charge Compression Ignition (PCCI), and Reactivity Controlled Compression Ignition (RCCI), are compared with conventional diesel combustion in a production, light-duty diesel engine from an alternative fuel perspective to come up with a befitting strategy and fuel to achieve wider operating range and lower emissions. The fuel selection strategy based on the fundamental fuel property requirements of the three LTC strategies has been discussed in detail. The baseline reference data is fixed by comparing three LTC strategies with conventional diesel combustion using diesel and gasoline as reference fuel at 40% load, the maximum common achievable load among the three LTC strategies. This is followed by an investigation of the effect of alternative fuels across three LTC strategies to address the shortcomings of the LTC strategies. The results show that the engine operating load range could be extended, and HC and CO emissions are reduced significantly with alternative fuels in the three LTC strategies. [ABSTRACT FROM AUTHOR]

Low Temperature Combustion (LTC) strategies are most promising to simultaneously reduce oxides of nitrogen (NOx) and soot emissions from diesel engines along with offering higher thermal efficiency. Commercial wide spread implementation of diesel LTC strategies requires several challenges to be addressed, including lack of precise ignition timing control, widening the narrow operating load ranges and reducing high unburned fuel emissions. These challenges can be addressed through modifications in the engine or fuel design or both. The timing and rate of combustion in several LTC strategies are controlled primarily by the chemical kinetics of the fuel. Since, diesel fuel reactivity and volatility are tailor-made to perform well under conventional diesel combustion conditions, its application in LTC poses several problems, as highlighted in this paper. Hence, it is important to identify suitable alternative fuels for the different diesel LTC strategies. The published literature on LTC over the past 25 years is critically analyzed to discuss the evolution of the different diesel LTC strategies, their operability limits, the challenges and the controlling parameters for each strategy. This is followed by in-depth analysis of the role of the fuel and the fuel requirements for each strategy. Further, the importance of adopting a hybrid surrogate modeling approach to enable numerical simulation of diesel LTC is highlighted. A novel attempt of relating various diesel low temperature combustion (LTC) strategies based on the approach followed to achieve positive ignition dwell through different injection strategies, utilizing high exhaust gas recirculation (EGR), and dual fuels is presented. The need for replacing diesel with alternative liquid fuels in LTC strategies is presented by highlighting the fundamental problems associated with diesel fuel characteristics. The review concludes by suggesting potential alternative fuels for various diesel LTC strategies and provides directions for future work to address the challenges facing compression ignition LTC operation. [ABSTRACT FROM AUTHOR]

From the past till the present there has been numerous direct filling materials introduced in the dentistry. These materials replaces the specialized tissues of the tooth that have been lost due to caries, as it can further leads to impairment of shape and functioning of the tooth. These materials have exponentially evolved ranging from amalgam to Glass Ionomer Cement and composites. GIC is well liked in dentistry due to its fluoride releasing nature, it is aesthetically good and have variable other properties. But due to its poor mechanical properties it cannot be used in stress bearing areas. To overcome the shortcomings, new materials have been introduced that is Cention-N. Cention-N not only releases fluoride but also release calcium and hydroxide ions. The hydroxyl ions emission can neutralize the acidity caused by the microorganisms which leads to prevention of demineralization. Many factors affect the amount of fluoride release in GIC and Cention-N. Anticariogenic effect of fluoride depends on the amount and time of fluoride release. Due to release of ions from these materials there can be effect on the bond strength of GIC and Cention-N. So the aim of this study is to find the effect of fluoride release on bond strength of Cention-N and GIC. [ABSTRACT FROM AUTHOR]

Justification: A number of guidelines are available for management of congenital heart diseases from infancy to adult life. However, these guidelines are for patients living in high income countries. Separate guidelines, applicable to Indian children, are required when recommending an intervention for congenital heart diseases, as often these patients present late in the course of the disease and may have co-existing morbidities and malnutrition. Process: Guidelines emerged following expert deliberations at the National Consensus Meeting on Management of Congenital Heart Diseases in India, held on 10th and 11th of August 2018 at the All India Institute of Medical Sciences, New Delhi. The meeting was supported by Children's HeartLink, a non-governmental organization based in Minnesota, USA. Objectives: To frame evidence based guidelines for (i) indications and optimal timing of intervention in common congenital heart diseases; (ii) follow-up protocols for patients who have undergone cardiac surgery/catheter interventions for congenital heart diseases. Recommendations: Evidence based recommendations are provided for indications and timing of intervention in common congenital heart diseases, including left-to-right shunts (atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus and others), obstructive lesions (pulmonary stenosis, aortic stenosis and coarctation of aorta) and cyanotic congenital heart diseases (tetralogy of Fallot, transposition of great arteries, univentricular hearts, total anomalous pulmonary venous connection, Ebstein anomaly and others). In addition, protocols for follow-up of post surgical patients are also described, disease wise. [ABSTRACT FROM AUTHOR]