reduction of exhaust emissions is a major research task in diesel engine development in view of increasing concerns regarding environmental protection and stringent exhaust gas regulations. simultaneousreduction of nox emissions and particulate matter is quite difficult due to the soot/nox trade-off and isoften accompanied by fuel consumption penalties. towards this aim, automotive engineers ha...

immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. this study was done to compare the apical extrusion of naocl in an immature root delivered using endovac and needle irrigation.eighty freshly extracted maxillary central incisors were decoronated followed by access ca...

We analyze the difference between imprecision and uncertainty, trying to clarify their difference, in particular when possibility theory is introduced. We compare the applicablity of the various models for uncertainty.

A review on the present state of the baryogenesis is given with an emphasis on electroweak baryogenesis. Technical details of the numerous models considered in the literature are not elaborated but unresolved problems of the isssue are considered. Different logically possible alternatives of the electroweak scenarios are presented. A possible impact of baryogenesis on the universe structure for...

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Today, the most urgent problem of existing and future nuclear power industry is to ensure environmental safety operation reactor units (NPPs) plants (NPPs). It solved thanks application deeply echeloned protection an anti-accident complex methods means for effective control active zones (AZR). However, danger NPPs in world from time manifests itself form severe post-project accidents catastroph...

highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (n) or of copolymerizing them with ethene (e) or propene (p). the polymers obtained show exciting structures and properties. e-n copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their micr...

The proper functioning of a catalytic converter requires precise regulation of A/F to the stoichiometric value. The control of A/F is usually based on regulating the fuel ow in proportion to air ow changes imposed by the driver. However, due to the relatively long time delays in the fuel feedback loop, the controller cannot properly compensate for rapid air ow changes. To overcome this de cienc...

The food security issue was addressed by the development of "modern agriculture" in the last century. But food safety issues and environment degradation were the consequences suffered as a result. Climate change has been recognized as the result of release of stored energy in fossil fuel into the atmosphere. Homogeneous crop varieties, machinery, pesticides and fertilizers are the foundation of...