Water quality management of a stretch of river Yamuna: An interactive fuzzy multi-objective approach

This paper presents an Interactive Fuzzy Multi-Objective Linear Programming (IFMOLP) model for water quality management in a river basin. The IFMOLP model formulated will first evaluate dissolved oxygen (DO) concentrations or DO deficits at a point in different reaches depending on the overall Biochemical Oxygen Demand (BOD) concentration present in the respective drain. Subsequently, the model incorporates the aspirations and conflicting objectives of the decision maker (DM) by taking into consideration the aspects relevant for pollution control boards as well as dischargers responsible for generating wastewater. The uncertainty associated with specifying the water quality criteria (based on DO concentration or DO deficit) and treatment cost to remove pollution level is incorporated by interacting the decision maker. In this process DM is asked to specify the reference aspiration levels of achievement for the values of all membership functions generated with respect to each objective. This provides flexibility for the pollution control authorities and dischargers to specify their aspirations. IFMOLP model developed herein is then used in a case study for the evaluation of optimal BOD removal in different drains located across the river Yamuna at New Delhi, India. The presented model will simulate the allocation of waste load efficiencies with satisfactory results which will indicate usefulness of the model in managing more complex river basins along with better flexible policies of water management.     

Signal processing in prolonged EEG recordings during intensive care

Methods for analyzing and displaying EEG signals are discussed. The increasing availability and affordability of powerful computer equipment makes possible the use of ever more sophisticated signal processing techniques, which extract relevant (but not readily discernible) information from long-term EEG recordings and can easily identify important features in the EEG. Whether these techniques are actually taken up in clinical practice is heavily dependent on how well they match clinical requirements. This article concentrates on requirements set in the context of long-term recordings in the ICU that demand the ability to process short-term discrete events as well as long-term trend information. A huge range of potentially useful signal processing techniques exists. This article illustrates the value of some of these techniques for ICU signals using the EEG recordings collected during the IMPROVE project     

Phase relations in the Nb-Pd-Hf-Al system

In support of computational design of coherent aluminide strengthened Nb alloys, the phase equilibria in a series of six Nb-Pd-Hf-Al alloys were investigated using scanning electron microscopy (SEM) and x-ray diffraction (XRD). All alloys were heat treated at 1200°C for 200 h, while three alloys were also heat treated at 1500°C for 200 h. Three-phase equilibria and two-phase equilibria were observed in two alloys at both temperatures. Two more alloys also exhibited three-phase equilibria at 1200 °C, while one alloy exhibited two-phase equilibria at 1200 °C. A final alloy revealed four-phase equilibria at both temperatures, confirming the presence of a unique tie-tetrahedron in the Nb-Pd-Hf-Al system. Based on the characterization of phases by SEM and XRD, the Nb-Pd-Hf-Al partial phase diagram at 1200 °C has been constructed. Such phase diagrams provide the basis for designing precipitation-strengthened Nb-based superalloys.     

Optimal mixing to improve the performance of batch and continuous fermentations with recombinant Escherichia coli

Fermentations with genetically altered bacteria tend to lose plasmids as the fermentation progresses. Methods such as two‐stage cultivation, cell recycle and the addition of antibiotics are commonly used to enhance plasmid stability. Here we examine a different method, the regulation of mixing in the bioreactor. In particular, large bioreactors are considered where uniform mixing is difficult to achieve and the probability of plasmid loss varies with the specific growth rate. For both batch and continuous cultivations of Escherichia coli C600 gal K containing the plasmid pBR Eco gap, it is seen through a model that both modes of operation exhibit high plasmid stability and cell growth when the broth is incompletely mixed, and mixing near and away from the point of inoculation are unequal. Thus, the natural incomplete mixing in large bioreactors may be utilized to improve plasmid stability. A practical method to implement this idea is suggested. Copyright © 2005 Society of Chemical Industry     

Screen‐printed biosensor for allergens

Allergen levels in indoor environments, leading to many diseases, eg asthma, rhinitis and conjunctivitis, affect a large and increasing fraction of the population. A quite effective and inexpensive method of a rough but very rapid overall assessment of total allergen level in the environment has been developed. The method involved estimation of protein in allergen extracts by screen‐printed electrodes using two different techniques. The biosensor comprised a rhodinised carbon working electrode, a silver/silver chloride reference electrode and a carbon counter electrode. In the first method the enzyme protease reacted with allergen protein to release amino acid, which produced hydrogen peroxide in the presence of amino acid oxidase. This was detected amperometrically. The second method used potassium bromide as electrolyte and the electrode was subjected to dual potential. Bromine, released due to electrolysis at higher potential, was consumed by the allergen protein at lower potential. In the first method, a unique technique was used to microencapsulate the enzyme protease and immobilise it on the surface of the electrode by in‐situ polymerisation to avoid contact with the amino acid oxidase. A total of seven allergens were tested and the results gave a good correlation with the standard protein measurement method. Environmental specimens from indoors, schools and workplaces can be evaluated for the aeroallergens produced by dust mites, animal hairs, cockroach debris, pollens, etc as a means of determining the exposure risk. Copyright © 2005 Society of Chemical Industry     

Social conflicts and their remedies in the distribution of canal water: Case study of the Damodar valley irrigation project,India

Lower availability of water in canals has caused damage of control structures, breach of minors and sub‐minors and erection of cross bunds to obtain water for crops. This misappropriation has resulted in inter‐ and intra‐village conflicts in the area of the Damodar Valley Irrigation Project in West Bengal. The conflicts are mostly caste based, as is prevalent in Northern India, and subject to political involvement. In the head reach the conflicts over the distribution of water are solved by the intervention of village‐level institutions with the help of community development blocks and irrigation officials. But in the tail reach the village‐level institutions and government officials have played a very limited role in resolving the conflicts. This article examines the nature and causes of the conflicts and some solutions are suggested.     

CFNN-PSO: An Iterative Predictive Model for Generic Parametric Design of Machining Processes

ABSTRACT

Every production process consists of a large number of dependent and independent variables, which substantially influence the quality of the machined parts. Due to the large impact of process variabilities, it is difficult to design optimal models for the machining processes. Mathematical or numerical models for production processes are resource driven, which are not cost effective approaches in terms of computation and economical production. In this paper, a new artificial neural network (ANN) based predictive model is introduced, which exploits particle swarm optimization (PSO) algorithm to minimize the root mean square errors (RMSE) for the network training. This approach can effectively obtain an optimized predictive model that can calculate precise output responses for the production processes. In order to verify the proposed approach, two case studies are considered from literature and shown to produce significant improvements. Furthermore, the proposed model is validated on abrasive water jet machining (AWJM) with industrial garnet abrasives and optimal machining conditions have been obtained with optimized responses, which are substantially improved while compared with gray relational analysis (GRA).