Analysis of groundwater quality using fuzzy synthetic evaluation

This paper reports the application of fuzzy set theory for decision-making in the assessment of physico-chemical quality of groundwater for drinking purposes. Methodology based on fuzzy set theory used to express the quality of water in the imprecise environment of monitored data and prescribed limits given in a non-probabilistic sense. Fuzzy synthetic evaluation model gives the certainty levels for the acceptability of the water based on the prescribed limit of various regulatory bodies quality class and perception of the experts from the field of drinking water quality. Application of fuzzy rule based optimization model is illustrated with 42 groundwater samples collected from the 15 villages of Ateli block of southern Haryana, India. These samples were analysed for 16 different physico-chemical water quality parameters. Ten parameters were used for the quality assessment using this approach. The analysis showed that four samples were in "desirable" category with certainty level of 35-58%, 23 samples were in "acceptable" category whose certainty level ranged from 37 to 75% and remaining 15 samples were in "not acceptable" category for drinking purposes with certainty levels from 44 to 100%. This concludes that about 64% water sources were either in "desirable" or "acceptable" category for drinking purposes.     

Morphologies of Sol–Gel Derived Thin Films of ZnO Using Different Precursor Materials and their Nanostructures

We have shown that the morphological features of the sol–gel derived thin films of ZnO depend strongly on the choice of the precursor materials. In particular, we have used zinc nitrate and zinc acetate as the precursor materials. While the films using zinc acetate showed a smoother topography, those prepared by using zinc nitrate exhibited dendritic character. Both types of films were found to be crystalline in nature. The crystallite dimensions were confined to the nanoscale. The crystallite size of the nanograins in the zinc nitrate derived films has been found to be smaller than the films grown by using zinc acetate as the precursor material. Selected area electron diffraction patterns in the case of both the precursor material has shown the presence of different rings corresponding to different planes of hexagonal ZnO crystal structure. The results have been discussed in terms of the fundamental considerations and basic chemistry governing the growth kinetics of these sol–gel derived ZnO films with both the precursor materials.

Cuphea a rich source of medium chain triglycerides: Fatty acid composition and oil diversity in Cuphea procumbens

The phenological characteristics, oil content, and fatty acid composition of 34 selections of Cuphea procumbens have been studied. The mean seed yield per plant was 9.7 ± 0.43 g. Maximum seed yield (16.7 g) was noticed in NBC‐27, while the average number of fruits per plant was 124.9 ± 10.7. The oil content in the seeds ranged from 16.7—28.7%, maximum being in NBC‐34. The fatty acid composition revealed the presence of capric acid (C10:0) in all the selections of C. procumbens as the major constituent of the oil ranging from 87.7—94.6%. C. procumbens showed its novelty as an alternative source of capric acid and may be utilized as a renewable resource in the production of plasticizers and lubricants which wholly depend on petrochemical import. Researches are in progress in order to obtain tolerant cultivars against wild plant characteristics and some delayed seed shattering plants have been identified.     

A design of experiments study on the factors affecting variability in the melt index measurement

Melt index (MI) is universally accepted as the primary specification in the thermoplastics industry. The standard according to which the MI measurement is made is ASTM D-1238. However, some variation in the MI measurement is possible, even when all ASTM D-1238 specifications are met. A thorough understanding of the sources and magnitude of variation is essential, since measurement error can have significant economic implications. Error in the MI measurement can cause a resin lot (about 190,000 pounds) to be erroneously classified as off-spec (leading to a loss of over US $20,000). A Resolution IV, six-factor, 1/4 fractional factorial design of experiments (DOE) study [with three replicates] was done to quantify the effect of various factors affecting variability in the MI measurement using two high-density polyethylene monitor resins with MI of 1.91 g/10 min (“low” MI) and 36.4 g/10 min (“high” MI). A major challenge was dealing with qualitative (e.g., “cleanliness”) and quantitative (e.g., “sample mass” or “temperature”) factors in the same DOE. For the high MI monitor, among the factors considered, the most significant (for the ranges considered) were found to be (in the order of importance): die orifice diameter, temperature, die cleanliness, barrel cleanliness, and sample mass. The following factors were also considered but not found (in the ranges considered) to be as significant: piston land (tip) diameter, load, piston cleanliness, preheat time, and piston curvature. For the low MI monitor, among the factors considered, the two most significant (for the ranges considered) were temperature and barrel cleanliness. This article gives practical and useful information for those who make and/or use MI measurements. As others have pointed out, much of such discussion related to melt indexers is also applicable to more sophisticated capillary rheometers. © John Wiley & Sons, Inc. J Appl Polym Sci 65:277–288, 1997     

Comparative stability of aspartame and neotame in yoghurt

The comparative stability of aspartame and neotame was monitored in yoghurt during its processing, fermentation and storage. A solid‐phase extraction method was suggest changing it to developed for the isolation of aspartame and neotame. Pasteurisation (85 °C/30 min) resulted in approximately 47% and 3% loss of aspartame and neotame, respectively. During fermentation, 3% loss of aspartame was observed, but no loss of neotame. There was no significant effects on the stability of either aspartame or neotame during storage (4–7 °C/15 days). The results indicated that neotame was more stable than aspartame under both pasteurisation and fermentation conditions; however, during storage, both sweeteners exhibited excellent stability.     

Optimisation of a process for production of pomegranate pulp and flaxseed powder fortified probiotic Greek dahi

Fortified probiotic Greek dahi was formulated with pomegranate pulp (PP) and flaxseed powder (FP). The product variables, viz. PP, FP and incubation time, were optimised based on chemical, sensory and textural attributes. The study revealed that PP significantly affected the acidity and antioxidant content, while FP influenced the sensory and textural properties of the product. The optimum conditions were 15% PP, 2% FP and 12‐h incubation time. The developed fortified probiotic Greek dahi is a potential synbiotic food.     

Experimental Investigation and optimization of Process Parameters for Shear Strength of Compound Cast Bimetallic Joints

Joining of A356 alloy and magnesium was carried out by vacuum assisted sand mold compound casting process. Microstructure at the joint interface was studied by using optical microscope, scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffractometer. Characterization indicated that a relatively uniform joint interface was obtained. The joint interface was composed of three distinct layers containing Mg₂Al₃ on aluminum side, Mg₁₇Al₁₂?+?δ eutectic structure on magnesium side and Mg₁₇Al₁₂ as middle layer. As a result of interaction between silicon, present in A356 with magnesium, Mg₂Si compound was formed. Push out test was conducted on electronics universal testing machine to measure the shear strength across the joint interface. The important process parameters (grit size of sand paper, insert temperature, pouring temperature and vacuum pressure) were optimized to maximize the shear strength. Optimization was carried out by using response surface methodology, desirability analysis and genetic algorithm (GA) techniques. It was observed that the shear strength increased by 14.21, 8.60 and 4.80% with genetic algorithm, desirability analysis and regression model respectively. GA reported the optimal value of shear strength.     

GA Approach for Optimization of Surface Roughness Parameters in Machining of Al Alloy SiC Particle Composite

Experiments were carried out using carbide turning inserts on AA7075/10?wt.% SiC (particle size 10-20???m) composites to get actual input values to the optimization problem, so that the optimized results are realistic. By using experimental data, the regression model was developed. This model was used to formulate the fitness function of the genetic algorithm (GA). This investigation attempts to perform the application of GA for finding the optimal solution of the cutting conditions minimum value of surface roughness. The analysis of this investigation shows that the GA technique is capable of estimating the optimal cutting conditions that yield the minimum surface roughness value. With the highest speed, the lowest feed rate, the lowest depth of cut, and the highest nose radius of the cutting conditions' scale, the GA technique recommends 1.039???m as the best minimum predicted surface roughness value. This means that the GA technique has decreased the minimum surface roughness value of the experimental sample data, regression modeling and desirability analysis by about 3%, 1%, and 2.8%, respectively.     

Numerical investigation of hydrogen absorption in a stackable metal hydride reactor utilizing compartmentalization

In this paper, a three-dimensional model for hydrogen absorption in a metal alloy has been developed, validated against the experimental data in the literature, and then applied to a novel design for a hydrogen storage unit. The proposed design is similar to the fuel cell stack, but here the Membrane Electrode Assembly (MEA) has been replaced by a metal hydride (MH) reactor placed between the flow-field plates. These are stacked together to achieve the required amount of hydrogen storage. The flow-field plates have channels engraved on one side for hydrogen supply and on the other, for coolant/heating medium. It is known that the effectiveness of a hydrogen storage unit is directly related to its heat transfer area, and therefore, the choice of its geometry is very important. The larger the size, the more the resistance to heat transfer. Although, the internal tubular heat exchangers have proven to be effective in heat transfer, they pose severe challenges such as cooling/heating medium leakage due to tube erosion, stresses generated, etc. and they displace the active metal hydride from the tank. The present stacked MH reactor configuration helps to overcome these challenges by stacking small MH reactors together and there is no chance of the cooling/heating medium leaking into the metal hydride. Numerical simulations were performed to investigate the effect of coolant flow rate and percentage of flow-field plate rib area exposed to the MH reactor on temperature evolution and the amount of hydrogen stored. Further, a detailed study was carried out to understand the effect of compartmentalization of the MH reactor on temperature distribution. The results revealed that compartmentalization substantially helps to uniformly distribute the temperature in the metal bed, which is very important to maintain uniform utilization of the metal powder. Consequently, the uniform metal powder density for repeated absorption-desorption cycles without significant loss of its hydrogen storage capabilities.