Filtration of Iron Ore Slime using Synthesized Co-Polymer

The present paper reports study on filtration of iron ore slimes using the co-polymer synthesized by grafting polyacrylamide chains on starch backbone. The efficacy of the synthesized polymer was tested for the filtration of iron ore slimes following flocculation. The filtration rate increases with increasing flocculant dosage. However, the improvement is marginal at higher flocculant dosage. The filtration rate decreases with increasing pulp density and/or increasing pH. The filtration efficacy of synthe-sized polymer is comparable with the imported one, Magna-floc 1011 at neutral pH. At the alkaline pH, the initial rate of filtration is higher with Magnafloc 1011 compared to the synthesized polymer. The turbidity of filtrate is, however, more than 500 NTU in the former case. The filtra-tion data fits Kozeny's equation at constant pressure

Predicting Blast-Induced Ground Vibrations in Some Indian Tunnels: a Comparison of Decision Tree, Artificial Neural Network and Multivariate Regression Methods

The present study compares three different techniques (decision tree, artificial neural network and multivariate regression analysis) for predicting blast-induced ground vibrations in some Indian tunnelling projects. The performance of these models was also compared to site-specific conventional predictor equations. A database consisting of 137 vibration records was randomly divided into training and testing sets for model generation. Eight input parameters (total charge, tunnel cross-section, maximum charge per delay, number of holes, hole diameter, distance from blasting face, hole depth and charge per hole) were selected for model development using bivariate correlation analysis. Results indicated that the decision tree is best suited for predicting vibrations. The decision tree further suggested that the intensity of near-field ground vibrations is mainly affected by total charge fired in a round, whereas the intensity of far-field vibrations is governed by maximum charge per delay and charge per hole. Conventional ground vibration predictors and machine learning techniques such as neural networks do not depict the relationship between input and output parameters. However, the present study substantiates that the decision tree can be a good tool for precise prediction of ground vibrations. Further, the decision tree can classify and relate different blast design parametersfor refining blast designs to control ground vibrations on site

Evaluation of stress intensity factor of multiple inclined cracks under biaxial loading

A finite rectangular plate of unit thickness with two inclined cracks (parallel and non parallel) under biaxial mixed mode condition are modelled using finite element method. The finite element method is used for determination of stress intensity factors by ANYSIS software. Effects of crack inclination angle on stress intensity factors for two parallel and non parallel cracks are investigated. The significant effects of different crack inclination parameters on stress intensity factors are seen for lower and upper crack in two inclined crack.The present method is validated by comparing the results from available experimental data obtained by photo elastic method in same condition

Effect of Boundary Condition on Pre-Existing Crack Under Fatigue Loading

ABSTRACT In this paper, the present investigation has been conducted keeping in mind some of the problems concerning the crack propagation direction and growth under constant loading in an inclined crack geometry. The present studies mainly focused on the development and modifications in the crack growth criterion to account the biaxial, shear loading and number of stress terms. Existing criteria for the prediction of crack initiation direction have been modified taking higher order stress terms. The effective methods of experimentally determining the stress intensity factor for a body containing a crack is to analyze the isochromatic pattern obtained from a photoelastic model. The effect of biaxial load factor, crack angle, Crack length/width of specimen and length of specimen/width of specimen were studied and a regression model was developed for geometry correction to predict stress intensity factor for tearing mode and intensity factor for shearing mode. This approach is being used to predict crack growth trajectory under biaxial cyclic loading by assuming that the crack may grow in a number of discrete steps using the vectorial method. MTS criterion (Maximum Tangential Stress criterion) is used for prediction of crack initiating angle. The crack growth trajectory has been determined by cycle simulation procedure

लाख शब्दावली (अंग्रेजी - हिंदी) Technical terms related to Lac

लाख शब्दावली (अंग्रेजी - हिंदी) Technical terms related to La

Efferocytes release extracellular vesicles to resolve inflammation and tissue injury via prosaposin-GPR37 signaling.

Macrophages release soluble mediators following efferocytic clearance of apoptotic cells to facilitate intercellular communication and promote the resolution of inflammation. However, whether inflammation resolution is modulated by extracellular vesicles (EVs) and vesicular mediators released by efferocytes is not known. We report that efferocyte-derived EVs express prosaposin, which binds to macrophage GPR37 to increase expression of the efferocytosis receptor Tim4 via an ERK-AP1-dependent signaling axis, leading to increased macrophage efferocytosis efficiency and accelerated resolution of inflammation. Neutralization and knockdown of prosaposin or blocking GRP37 abrogates the pro-resolution effects of efferocyte-derived EVs in vivo. Administration of efferocyte-derived EVs in a murine model of atherosclerosis is associated with an increase in lesional macrophage efferocytosis efficiency and a decrease in plaque necrosis and lesional inflammation. Thus, we establish a critical role for efferocyte-derived vesicular mediators in increasing macrophage efferocytosis efficiency and accelerating the resolution of inflammation and tissue injury

Evaluation of stress intensity factor of multiple inclined cracks under biaxial loading

A finite rectangular plate of unit thickness with two inclined cracks (parallel and non parallel) under biaxial mixed mode condition are modelled using finite element method. The finite element method is used for determination of stress intensity factors by ANYSIS software. Effects of crack inclination angle on stress intensity factors for two parallel and non parallel cracks are investigated. The significant effects of different crack inclination parameters on stress intensity factors are seen for lower and upper crack in two inclined crack. The present method is validated by comparing the results from available experimental data obtained by photo elastic method in same condition

Characterization and its implication on beneficiation of low grade iron ore by gravity separation

Studies were undertaken on low grade iron ore sample from Noamundi iron ore mines. The objective of this study was to examine the possibility of the physical beneficiation of low grade iron ore sample by physical methods for the blast furnace route of iron production. The present investigation relies on petrography and ore mineralogical characterization, ore textures (primary, secondary, metamorphic), liberation characters and its impact on the mineral beneficiation methods to produce quality concentrate. The geological characters, alteration mineralogy, morphometric variation, ore microscopy (using model microscope with transmitted and reflected light) and thereby understanding the genesis has given proper insight into the occurrence of various minerals. In addition to this, representative samples were employed for detailed investigation by using XRD, SEM-EDS and cathodoluminescence (CL) studies for confirmation of major as well as minor ore minerals and associated gangue minerals. Investigations suggest that lateritic iron ore samples obtained from the study area are composed of hematite (two generations), goethite (two generations) and limonitic material (younger generation) in association with major gangue minerals such as clay minerals (kaolinite, illite), bauxitic minerals(gibbsite, boehmite and diaspore), cryptocrystalline silica(japer, chert) and crystalline quartz as well as apatite and collophane. Fair liberation obtained below 74 micron size. It was interesting to find that inspite of the complex mineralogy of iron ore, beneficiation results using gravity separation like multi gravity separator (MGS), particularly in finer size ranges was encouraging. The result of ore-gangue mineralogical studies were found quite useful in evaluating the separation efficacy of gravity separation process. The process mineralogical data corroborated well with beneficiation results

Enhancement of Image and Video using In-Painting Technique

A comprehensive image in-painting method was proposed to enhance the two critical task in the prior hybrid method, which are setting up the best application order for in-painting textural and structural missing regions and extracting the sub-image containing best candidates of source patches to be used to fill in a missing region. By integrating our ‘execution-order analysis based solution ‘to task one and our image ‘context –driven source image extraction solution ‘to task two. We were able to consistently improve in-painting quality compared with that of the previous non-hybrid in-painting method while even spending much shorter processing time compared with the conventional hybrid in-painting methods. Image in-painting is process of restoring or removing object in an image. The basic task is to fill the surrounding information to inner sides. This technique boost numerous application like restoring or removing degraded part in image , text removal , stamp or symbol removal and disocclusion in image based rendering (IBR). The problem definition in image in-painting is that it is ill-posed inverse problem. It means that there is no well-defined particular technique. Image in-painting techniques are broadly categorized in two types. First, texture based in-painting and another is the structure based in-painting. The main motivations related to this technique are that in-painting results are degraded for images with combination of texture and structure features. Another motivation is that it consumes more computation time. The working principle of image in-painting is that assumption of pixels in the known and unknown parts of image that share the similar statistical and geometrical structure. In past literature, diffusion-based in-painting was introduced that are best suited for straight line, parabolic curve and for small region. The main drawback of diffusion method is that are not work on unconnected edges and also produces Gradient Reversal artifacts after restoration. With advancement of technology, sparse based in-painting and examplar based in-painting are considering for eliminating problem.In this digest, sparse based in-painting is introduced on basis of discrete wavelet transform technique based on finding the region pixel, calculating pixel priority and normalizing the in-paint region boundary.An image can be mathematically represented as [1] =⊂ → → (), Where x is a vector indicating spatial-domain pixel, which in the case of gray scale image (n=2) and is defined as x = (x, y). For color image (m=3) and is defined in (R, G, B) color space. The goal of image in-painting is to calculate the (R, G, B) components of the pixels situated at position x in the unspecified region U, from the pixels situated in the known region S, to finally form the in-painted image. The purpose in term of quality is that reconstructed part seems natural to human naked eye, and is physically imaginable as possible

Moving in and out of vulnerability : interrogating migration as an adaptation strategy along a rural-urban continuum in India

Drawing on life history interviews, the paper explores the role of migration and commuting in addressing livelihood vulnerability along a rural–urban continuum in Karnataka, India. Using life histories as a methodological tool can complement econometric approaches, allowing for in‐depth and temporally sensitive inquiry into the drivers and consequences of migration. The study locates present‐day vulnerability in Kolar and Gulbarga as points on a regionally differentiated development pathway. Both Kolar and Gulbarga are sites of prominent out-migration due to their geographical contexts. Findings show drivers of migration are based on livelihood expectations, and perceived lack of opportunities in rural areas.UK Department for International Development (DFID