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‘Robustness’ is an important concept used in quality engineering for the improvement of quality in a manufacturing process. A process which is insensitive to noise variation is called a robust process. The robustness is modelled by several researchers and practioners for its design and implementation in a manufacturing process. A review of all these approaches is essential in order to assess their strengths, limitations and applicability under different process conditions and constraints. Over the years, many of these approaches have found widespread application in measuring, assessing and modelling of process robustness in manufacturing and other industries. In this paper, an attempt has been made to review critically the existing approaches as proposed and applied for measuring and evaluating robustness of manufacturing processes. Based on the critical appraisal, the key issues are identified and a generic framework for modelling and measuring of process robustness in single- and multi-stage manufacturing processes is presented. [ABSTRACT FROM PUBLISHER]

The study of robustness in single-stage manufacturing has been explored by a large number of researchers and practitioners. However, modelling of robustness in multi-stage manufacturing using multivariate data is seldom used. The aim of this paper is to develop a methodology to model process robustness in a serial multi-stage manufacturing system. Combining statistical regression, Taylor series expansion, the root-sum-squares method and a variation model, the methodology proposes a measurement system for robustness. The resulting metric, while quantifying robustness, measures absorbed and transmitted variations across the stages of a manufacturing process. Using the methodology in a serial two-stage worm gear manufacturing process, the levels of robustness and both absorbed and transmitted variations are determined, thus identifying significant variations across manufacturing stages. The details of this application with the types of corrective actions as required for minimisation of process performance deterioration are presented. [ABSTRACT FROM PUBLISHER]

Dynamic variation in power system frequency is required to be estimated in order to implement correcting measures. This study presents power system frequency estimation by using a leaky least mean-square algorithm. The proposed approach uses a variable leak adjustment technique to avoid drifting of the weights involved in the estimation mechanism. A variable adaptation step size is also incorporated in the algorithm to attain faster convergence. The performance of the proposed algorithm is studied through simulations for several critical cases that often arise in a power system. These studies show that the present algorithm is superior over the existing ones in estimating power system frequency. Studies made on experimental data also support the superiority. [ABSTRACT FROM AUTHOR]

Reduction of risk of occupational injuries is one of the most challenging problems faced by industry. Assessing and comparing risks involved in different jobs is one of the important steps towards reducing injury risk. In this study, a comprehensive scheme is given for assessing and comparing injury risks with the development of injury count model, injury risk model and derived statistics. The hazards present in a worksystem and the nature of the job carried out by workers are perceived as important drivers of injury potential of a worksystem. A loglinear model is used to quantify injury counts and the event-tree approach with joint, marginal and conditional probabilities is used to quantify injury risk. A case study was carried out in an underground coalmine. Finally a number of indices are proposed for the case study mine to capture risk of injury in different jobs. The findings of this study will help in designing injury intervention strategies for the mine studied. The job-wise risk profiles will be used to prioritise the jobs for redesign. The absolute indices can be applied for benchmarking job-wise risks and the relative indices can be used for comparing job-wise risks across worksystems. [ABSTRACT FROM AUTHOR]

An intelligent multisensor integration and fusion model that uses fuzzy logic is developed. Measurement data from different types of sensors with different resolutions are integrated and fused based on the confidence in them derived from information not usually used in data fusion, such as operating temperature, frequency range, fatigue cycles, etc. These are fed as additional inputs to a fuzzy inference system (FIS) that has predefined membership functions for each of these variables. The output of the FIS are weights that are assigned to the different sensor measurement data that reflect the confidence in the sensor's behavior and performance. A modular approach is adopted. It allows adding or deleting a sensor, along with its fuzzy logic controller (FLC), anytime without affecting the entire data fusion system. This paper presents a preliminary model that fuses the data from three different types of sensors that monitor the strain at a single location in a cantilever beam. This will be later extended to sensors that will be fixed at different locations on the same beam. The results from the proposed work are a stepping stone toward the development of generic autonomous sensor models that are capable of data interpretation, self-calibration, data fusion from other sources, and even learning so as to improve their performance with time. This work is aimed at the development of smart structural health monitoring systems, but has applications in diverse fields such as robotics, controls, target tracking, and biomedical imaging [ABSTRACT FROM PUBLISHER]

The bacteriological analysis of 50 drinking water samples from various sources in different parts of Lucknow city showed coliforms ( >10/100ml) and faecal coliforms ( >1/100ml) in 56% and 44% of samples, respectively. Escherichia coli were isolated from 13 samples. All the isolates were found to be enterotoxigenic. Out of the total E. coli strains only six exhibited antibiotic resistance. Multiple and single resistances were found in 4 and 2 resistant strains, respectively. These strains also showed transfer of their antibiotic resistances at significant frequencies. Presence of transferable antibiotic resistance, particularly in enterotoxigenic E.coli in drinking water due to the faecal contamination, is a major factor for incidences of various diarrhoeal diseases. [ABSTRACT FROM PUBLISHER]

Immobilized metallic Silver ion on Alumina was found to be effective in the removal and inactivation of thermotolerant E. Coli. within 10 to 15 seconds contact time. In this process, bacteria are not only adsorbed on the solid support but are also inactivated due to bactericidal and bacteriostatic effect of Silver ions. This filter material may potentially be useful for the disinfection of potable water at individual and for community water systems. [ABSTRACT FROM PUBLISHER]

Flyash as an adsorbent was found to be effective for the removal of heavy metals after generation with 2.3% HCl at about pH 6. Iron, lead, manganese and chromium ions were studied for their adsorption efficiency. In the experiments with metals separately lead showed maximum 93% adsorption. In a mixture iron showed maximum adsorption and for lead adsorption was reduced to 28%. Chromium showed minimum adsorption 6.3% in individual experiment and 13.03% in mixture. On the basis of data presented in this communication flyash may be tested at pilot plant level instead of slow sand filtration, for its potential for the treatment of drinking water. [ABSTRACT FROM PUBLISHER]

The structural features and fracture morphology of raw and chemically treated pineapple leaf fiber have been studied using scanning electron microscopy. Pineapple leaf has a multicellular structure, and alkali treatment clearly reveals the ultimate fibers. Surface morphology progressively changes with gradual removal of noncehulosic constituents like lignin and hemicellulose. Fracture morphology shows that there is a uniform sharing of the load in the ultimate fibers of raw pineapple leaf, whereas treated leaf shows irregular fractures characterized by the slippage of individual ultimate fibers. [ABSTRACT FROM PUBLISHER]

Scanning electron microscope observations have been made of needle punched and adhesive bonded nonwoven fabrics from jute, coir, goat hair, wool, viscose, polypro pylene, and acrylic fibers. Fibers in the needle punched fabric form layered structures, and their arrangement in the fabric depends on the type of fibers and mode of needling. With adhesive bonded fabrics, both point and web bonds are found, and in some fabrics the fiber surface is completely obscured by the adhesive material so that the surface structure of the fibers is not visible. [ABSTRACT FROM PUBLISHER]

Infrared spectra of degummed ramie fibers (2-3% gum content) in untreated and alkali treated conditions at room temperature were observed over the frequency range 4000-300 cm -1 using the KBr disk technique. The changes in the spectra are discussed generally. The sharp change in the spectrum due to transition from cellulose I to cellulose II was observed in the concentration range 12-15% (w/w) of alkali. The transition to cellulose II was accompanied by a crimp in the fiber. [ABSTRACT FROM PUBLISHER]

A microprocessor-based system for deriving variance-length curves in conjunction with Uster evenness tester has been described with particular reference to jute yams. Reliable variance-length curves can be obtained easily, and the higher CVs often encountered in jute yarns do not pose any problem. Thick and thin portions of the yarns can also be counted without additional circuitry. [ABSTRACT FROM PUBLISHER]

Meridional x-ray reflections have been recorded for jute fiber of different varieties by the tilted-fiber technique. Hermans' orientation angle and orientation factor have been determined from the equatorial and the meridional (040) reflection. A better agreement is observed between the intensity distributions of the equatorial (002) reflection and the meridional (040) reflection than between the (040) and the composite (101) & (101) reflections. [ABSTRACT FROM PUBLISHER]