Weak Phase gamma Using Isospin Analysis and Time Dependent Asymmetry in B_d -> K_s pi^+ pi^-

We present a method for measuring the weak phase gamma using isospin analysis of three body B decays into K pi pi channels. Differential decay widths and time dependent asymmetry in B_d -> K_s pi^+pi^- mode needs to be measured into even isospin pi pi states. The method can be used to extract gamma, as well as, the size of the electroweak penguin contributions. The technique is free from assumptions like SU(3) or neglect of any contributions to the decay amplitudes. By studying different regions of the Dalitz plot, it is possible to reduce the ambiguity in the value of gamma.Comment: 11 pages, 1 figur

Application of metallography in failure investigations: some case studies

Metallography is a tool to know the internal condition of the material and no investigation can be initiated without this. It can be both nondestruc¬tive i.e., in-situ metallography, as well as destructive i.e.. cutting the relevant parts from the site to undertake investigation in the laboratory. In both the cases grinding, polishing and etching to reveal the microstructures remain the same. The only difference is the special tools and portable optical microscopes are used in the in-situ techniques to obtain replicas for laboratory use. Two types of etching are used to reveal macro and microstructures. The macro structures are viewed at 5 to 10 x, which reveal flow line, cold rolling fibres, welding zones, pores, dendrites, coarse grains etc. whereas microstructures reveal the micro constituents, pearlite, martensite, inclusions, precipitates, carbides, creep voids etc. at magnification of 50 to 1500 x. Metallography alone gives lot of information regarding the deviations of microstructures which are indication of the causes of failures. Some typical case studies are described in the present paper where metallography plays very important role, like : (i) Improper weld deposits to salvage the undersize rail axle, which led to premature failure, (ii) improper welding joints and lack of post weld heat treatment, which gave stress on the joint of cover dome of pressure vessel tank, which caused failure, (iii) revealing of tool marking and sulphide inclusions in the steel isolation valve of LPG storage tank, which led to premature failure, (iv) sensitization and stress corrosion cracking in S.S. cover dome of centrifuge used in the manufacture of NG explosive, which caused premature failure, (v) Improper heat treatment and forging were indicated by the microstructures which led to the premature failure of mining dragline sleeve. These are only a few investigations carried out in the laboratory in the recent past which justify that without metallography it is not possible to diagonise the causes of premature failures

Image Analysis & Quantitative Metallography

The metallographic examination constitutes simply a planar section view of a three dimensional structure. It is not enough to recognize this fact; one must also understand how shape in a three dimensional construction can deg-enerate into traces in random planar section.In fact, one must be able by mental visual skill to recreate from slices of hard boiled egg, the oblate ellipsoid when they came. For example, an inclusion, or porosity can appear to be different when observed in different planer section and the assessment of volume will be qualitative and only quantitative to the extent of visual judgement. Actual quantitative evaluation of inclusion and porosity, their shape and size distribution are very important for predicting the mechanical properties o the metals and alloys. Similarly, the grain size is another important factor in the hardenability of steels, ductility of brass and in the ductile-brittle transition of alloys. The amount of ferrite in stainless steels is a factor in their foregeability. The average flake size of graphite is a control parameter in the strength of gray cast iron. These are only a few instances where numerical limits to metall-ographic parameters arepractical factors in quality or production control. Since we can not obtain large number of specimens to get correct three dimensional picture, quantitative analysis is an appropriate alternative. Two factors must be assumed in all such quantitative studies. The planar section or sections be representative of the whole. In the matter of arriving at average values for dimensions of distributed particles one must have a know-ledge of the actual or approximate shape of the part- icles. Few particles are actually perfectly spherical. but this is a mathematical convenience

Specimen Preparation for Optical Microscopy

The most important single feature of metallographic technique is the preparation of specimens. This involves correct and representative sampling, cutting and grinding with a minimum of mechanical distortion, shaping the spec-imen or mounting the specimen, so that it can be conven-iently handled during the subsequent operations removing the rough grinding marks and can be polished free from scratches and mechanical distortion, and finally etching the specimen to reveal and differentiate the various phases present in the metallic matrix. Even though it appears very simple, but in reality their technical art needs great care, patient and continued practice

Effect of mindfulness on online impulse buying: Moderated mediation model of problematic internet use and emotional intelligence

Introduction: Online impulse buying behavior is an unplanned urge to buy a product or service in an online setting and it has several negative consequences for customers, such as guilt and financial distress, and e-commerce firms, such as higher returns and customer complaints. Evidently, it is important to examine the various psychological processes which may assist in a better understanding, therefore addressing the high prevalence of online impulse buying. This study builds upon self-regulation theory to explore how mindfulness influences online impulse buying, and examines problematic internet use as a mediator in the relationship between mindfulness and online impulse buying. Further, this study investigates how emotional intelligence as a moderator plays the role of a suppressant on the adverse impact of problematic Internet use which fuels online impulse buying. Method: A total of 598 individuals working with various servicebased industries responded to the questionnaire. Multiple regression and moderated mediation analysis was used using SPSS and AMOS for analyzing the data. Result: Problematic internet use mediates the relationship between mindfulness and online impulse buying behavior. Emotional intelligence negatively moderates the relationship between problematic internet use and online impulse buying behavior. Discussion: This study findings outlined the inverse relationship of mindfulness & online impulse buying, along with the mediating effect of problematic internet use between mindfulness and online impulse buying. Further, this study showed how emotional intelligence played an important role as a moderator by suppressing the adverse impact of problematic Internet use and preventing online impulse buying. The study offers implications to online marketers in regulating the unplanned purchase process—while minimizing uninhibited buying behavior that leads to regret, and the subsequent intention to return products. Further, social and theoretical implications are discussed