Improvements in Aircraft Gas Turbine Engines for the 90s

The gas turbine propulsion system has been playing the most significant role in the evolution and development of present-day aircraft, and has become the limiting technology for developing most new aircraft. However, the jet engine still remains the preferred propulsion choice. Aircraft gas turbines in one form or the other, viz. turbojet, turbofan, turboprop or turboshaft, have been used in commercial passenger aircraft, high performance military aircraft and in rotary wing aircraft (helicopters). The emphasis in engine development programmes world over seems to be in reducing fuel consumption, increasing thrust and in reducing weight

Flat Rating Concept Introduced in the GTX Engine

An attempt has been made to explain the flat rating concept introduced in the GTX engine being developed at GTRE. The contemporary high pressure ratio engines lose thrust rapidly with increase in compressor inlet total temperature (T1). This loss of thrust with increase in T1 becomes significant in the case of bypass engine, with thrust drop increasing with increase in bypass ratio. The concept of variable cycle achieved by varying the maximum cycle temperature in order to increase the available dry thrust is explained. In recent days this concept of variable cycle has been recognised in the design of engines for combat aircraft with particular reference to supersonic cruise at altitude. An attempt has also been made to explain the control law in order to achieve the flat rating

Determinants of turnover intentions among marketing and sales representatives in the UAE

This article identifies four determinants of turnover intentions among the marketing executives and sales representatives (reps).  Influence of these dimensions on such employees is investigated in an emerging market’s Fast Moving Consumer Goods (FMCG) distribution environment. Extensive review of the current literature on employee turnover intentions and specific review of turnover intentions among reps and marketing executives are conducted This study identifies four dimensions of determinants of turnover intentions among marketing and sales representatives of FMCG in an emerging market.  The results indicate that coordinated efforts by management to satisfy these dimensions lead to decreased turnover among marketing and sales reps of FMCG distributors.  This study offers understanding of the determinants of turnover intentions of turnover intentions among marketing and sales reps of FMCG distributors. This article conceptualizes the influence of performance appraisal, developmental pay, talent acquisition and training, and learning and development on turnover intentions of Marketing and sales reps working in FMCG distribution industry.  The article contributes to fill the knowledge gaps on the influence of these dimensions on turnover intentions.     Key words – Turnover intentions; Marketing and Sales representatives; Performance appraisal; HR strategies, Developmental pay, Talent acquisition

3-D kinematical conservation laws (KCL): evolution of a surface in R<SUP>3</SUP>-in particular propagation of a nonlinear wavefront

3-D KCL are equations of evolution of a propagating surface (or a wavefront) &#x03A9;t in 3-space dimensions and were first derived by Giles, Prasad and Ravindran in 1995 assuming the motion of the surface to be isotropic. Here we discuss various properties of these 3-D KCL. These are the most general equations in conservation form, governing the evolution of &#x03A9;t with singularities which we call kinks and which are curves across which the normal n to &#x03A9;t and amplitude w on &#x03A9;t are discontinuous. From KCL we derive a system of six differential equations and show that the KCL system is equivalent to the ray equations of &#x03A9;t. The six independent equations and an energy transport equation (for small amplitude waves in a polytropic gas) involving an amplitude w (which is related to the normal velocity m of &#x03A9;t) form a completely determined system of seven equations. We have determined eigenvalues of the system by a very novel method and find that the system has two distinct nonzero eigenvalues and five zero eigenvalues and the dimension of the eigenspace associated with the multiple eigenvalue 0 is only 4. For an appropriately defined m, the two nonzero eigenvalues are real when m&#62;1 and pure imaginary when m&#60;1. Finally we give some examples of evolution of weakly nonlinear wavefronts