Effect of thermal cycling process parameters on recrystallization kinetics for processing of fine-grained pure copper

The present work developed a two-step thermal cycling technique for processing of fine-grained pure copper for improved properties. This included initial annealing of specimens followed by heavy cold rolling and a series of heating and cooling cycles. The study investigated the important microstructural changes occurring in the cold deformed grains in the absence of phase transformations. A major interest of the present research was to closely describe the effect of thermal cycling parameters on the recrystallization and grain growth kinetics for processing of fine-grained structure. The study determined the optimum values of process parameters for the developed thermal cycling route including the extent of cold deformation, annealing temperatures, holding periods, and the number of thermal cycles. The thermal cycling process produced closely distributed fine grains with bi-modal microstructure leading to increased hardness and strength without any significant loss in electrical conductivity.     

Comparative separation analysis of direct and reverse flotation of dolomite fines

In the present investigation, beneficiation of a low-grade dolomite fines was carried out with the aim to remove the siliceous gangue content. Extensive experimental studies on direct and reverse flotation were carried out on low-grade ore by varying the critical process variables, and the performance was compared. The experimental results show that it is possible to reduce the silica content following both direct and reverse flotation processes. Further, direct flotation results show better control over the quality of the product while reverse flotation has an edge on the product yield.     

Routing,wavelength assignment and spectrum allocation for reconfigurable optical mesh networks having a combination of fixed and flexible spectrum ROADM nodes

Next generation of optical networks will witness the advent of flexible spectrum/grid reconfigurable optical add drop multiplexers (ROADMs). The pass band of these next generation ROADMs can be varied depending on the spectral width of the incoming signal. With the pass band becoming a variable, spectrum allocation becomes an added constraint to the currently employed routing and wavelength assignment (RWA) algorithm and hence turns it into a routing, wavelength assignment and spectrum allocation (RWSA) problem. In reality, the future networks will be a mix of “Fixed Spectrum” and “Flexible Spectrum” ROADM nodes. Considering this fact, the paper presents a novel RWSA algorithm. The proposed algorithm is applied on NSFNET and two sample networks—11 nodes, 30 node and the results are presented.     

Moving object detection using spatio-temporal multilayer compound Markov Random Field and histogram thresholding based change detection

Multimedia Tools and Applications - In this article, we propose a Multi Layer Compound Markov Random Field (MLCMRF) Model to spatially segment different image frames of a given video sequence. The...     

Impact of Martensite Spatial Distribution on Quasi-Static and Dynamic Deformation Behavior of Dual-Phase Steel

The effects of microstructure parameters of dual-phase steels on tensile high strain dynamic deformation characteristic were examined in this study. Cold-rolled steel sheets were annealed using three different annealing process parameters to obtain three different dual-phase microstructures of varied ferrite and martensite phase fraction. The volume fraction of martensite obtained in two of the steels was near identical (~ 19 pct) with a subtle difference in its spatial distribution. In the first microstructure variant, martensite was mostly found to be situated at ferrite grain boundaries and in the second variant, in addition to at grain boundaries, in-grain martensite was also observed. The third microstructure was very different from the above two with respect to martensite volume fraction (~ 67 pct) and its morphology. In this case, martensite packets were surrounded by a three-dimensional ferrite network giving an appearance of core and shell type microstructure. All the three steels were tensile deformed at strain rates ranging from 2.7 × 10^?4 (quasi-static) to 650 s^?1 (dynamic range). Field-emission scanning electron microscope was used to characterize the starting as well as post-tensile deformed microstructures. Dual-phase steel consisting of small martensite volume fraction (~ 19 pct), irrespective of its spatial distribution, demonstrated high strain rate sensitivity and on the other hand, steel with large martensite volume fraction (~ 67 pct) displayed a very little strain rate sensitivity. Interestingly, total elongation was found to increase with increasing strain rate in the dynamic regime for steel with core–shell type of microstructure containing large martensite volume fraction. The observed enhancement in plasticity in dynamic regime was attributed to adiabatic heating of specimen. To understand the evolving damage mechanism, the fracture surface and the vicinity of fracture ends were studied in all the three dual-phase steels.     

The Role of a Natural Language Conversational Interface in Online Sales: A Case Study

This paper describes the evaluation of a natural language dialog-based navigation system (HappyAssistant) that helps users access e-commerce sites to find relevant information about products and services. The prototype system leverages technologies in natural language processing and human-computer interaction to create a faster and more intuitive way of interacting with websites, especially for less experienced users. The result of a comparative study shows that users prefer the natural language-enabled navigation two to one over the menu driven navigation. In addition, the study confirmed the efficiency of using natural language dialog in terms of the number of clicks and the amount of time required to obtain the relevant information. In the case study, as compared to the menu driven system, the average number of clicks used in the natural language system was reduced by 63.2% and the average time was reduced by 33.3%.     

Characterisation of honey produced from different fruit plants of northern India

Studies were carried out to determine the affect of different fruit plant sources viz., Litche chinensis (litchi), Citrus sinensis (sweet orange), Ziziphus mauritiana (ber) and Prunus persica (peach) on moisture content, pH, free acidity, reducing sugars and sucrose contents, fructose/glucose ratio, ash and proline content, invertase and diastase activities, hydroxymethylfurfural and mineral (sodium, potassium, iron, calcium, zinc, and copper) contents as well as on rheological properties of honey. The source of honey had a significant (P < 0.05) effect on moisture content, free acidity, reducing sugar, fructose/glucose ratio, hydroxymethylfurfural content, invertase and diastase activities, sucrose content, proline content, ash content, pH and mineral content. The honey from various sources exhibited Newtonian behaviour and the activation energy ranged from 63.63 to 81.48 kJ mol^?1. Pattern recognition methods such as principal component analysis andlinear discriminate analysis were performed to classify honey on the basis of physico‐chemical properties and mineral content. The variables proline, potassium and free acidity exhibited higher discrimination power.     

‘SODEPT’ A Software for Design of Percolation Tank

Percolation tanks are widely used for increasing recharge of ground water resources. This has been used from centuries in arid and semi arid regions of India and is known by different indigenous name, viz. rapat, nadi etc. However not much work has been done on standardization of the design parameters of these tanks, and therefore most of the time, tanks are either over designed or under designed. The design parameters of the percolation tank and amount of water recharged to groundwater during different months depend upon area of catchment, hydrological cover complex characteristics of the catchment, rainfall characteristics of the area, evaporation loss and seepage rate of the tank bed. Since rainfall and evaporation are stochastic variables, their distribution should also be accounted for. Further the dimensions of the tank will vary with the level of probability of design. With this in view, a software has been developed for giving the design parameters of the percolation tank. The input data are long term daily rainfall and evaporation data, seepage rate of the tank bed which is a function of textural characteristics and hydraulic conductivity, area of catchment, hydrological complex characteristics defined by curve numbers, area available for construction of the tank (length and width) for excavated type of the percolation tank or width of the gully and slope of the drainage way for impounded type of the tank, and cost of the earthwork for different depths and lead. The output is capacity of the tank for most economic recharge per unit investment, total recharge during the year, recharge during monsoon and recharge during post monsoon months and expected storage level at the end of the monsoon.     

Adaptation techniques in wireless packet data services

Today's cellular systems are designed to achieve 90-95 percent coverage for voice users (i.e., the ratio of signal to interference plus noise must be above a design target over 90 to 95 percent of the cell area). This ensures that the desired data rate which achieves good voice quality can be provided “everywhere”. As a result, SINRs that are much larger than the target are achieved over a large portion of the cellular coverage area. For a packet data service, the larger SINR can be used to provide higher data rates by reducing coding or spreading and/or increasing the constellation density. It is straight-forward to see that cellular spectral efficiency (in terms of b/s/Hz/sector) can be increased by a factor of two or more if users with better links are served at higher data rates. Procedures that exploit this are already in place for all the major cellular standards in the world. In this article, we describe data rate adaptation procedures for CDMA (IS-95), wideband CDMA (cdma2000 and UMTS WCDMA), TDMA (IS-136), and GSM (GPRS and EDGE)