EFFECT OF DIFFERENT PREMILLING TREATMENTS ON DEHULLING OF BLACK GRAM (PHASEOLUS MUNGO L.)

Black gram is mainly used after dehulling. Various types of premilling treatments are applied for proper dehulling. In this study, premilling treatments such as the dry method, chemical and hydrothermal treatments were carried out. It was found that premilling treatments with certain chemicals such as sodium bicarbonate, acetic acid and alcohol were found effective in dehulling black gram. Several vegetable oils at varying concentrations (0.2, 0.4, 0.6, 0.8 and 1.0%) were used; it was found that 0.6% was optimal, except that sesame oil was effective even at 0.2%. Oil treatment gave dhal suitable for use in many traditional products. Although chemicals were effective, they had to be used at relatively high concentrations of approximately 5%. It was also found that a steaming time of 10–15 min was adequate to loosen the hull, resulting in easy dehulling. It was concluded that hydrothermal treatment could be used for dehulling black gram. However, hydrothermally pretreated dhal was not suitable for fermented products, in which case a conventional oil pretreatment method should be used with sesame oil preferred.

PRACTICAL APPLICATIONS

This study shows the effects of different premilling treatments on dehulling black gram. Black gram dehulling efficiency can be enhanced by premilling treatments such as dry method, chemical method or hydrothermal treatment. For practical application, it is important to give due consideration to the end product use of dehulled black gram. Hydrothermal treatment for 10 min is suitable for dehulling black gram if the finished product is used for nonfermented products, and dry method with sesame oil concentration of 0.4% w/w would suit both fermented as well as nonfermented products. This study could be used by black gram processors for optimizing process conditions and premilling treatment.     

Effect of high pressure on the dielectric properties of relaxor compositions [Pb(Fe1/2Nb1/2)O3]1-x-y-[Pb(Zn1/3Nb2/3)O3]x- [BaTiO3]y

Abstracts are not published in this journal     

Kinetics of Precipitation of α-Al2O3 in Polycrystalline Supersaturated MgO - 2Al2O3 Spinel Solid Solution

Supersaturated polycrystals of solid-solution spinel were heat-treated below the solvus temperature. Precipitation of α-alumina was examined by X-ray diffraction, microprobe, and scanning transmission electron microscopy. Precipitation kinetics followed classical time-temperature-transformation behavior: the precipitation rate was growth controlled at large undercoolings and nucleation controlled at low undercoolings. Scanning transmission electron microscopy and microprobe analysis revealed that the growth of precipitates was limited by interface reaction. Nucleation occurred throughout the polycrystal and was probably promoted by the grain boundaries. Precipitation was accompanied by the growth of pores at interfaces, presumably to accommodate the change in volume required by the phase transformation. Our observations in polycrystals contrast sharply with single-crystal work, where it has been reported that nucleation occurs at the free surface and that the formation of α-alumina is preceded by metastable phases.     

Structural characteristics of titanium coating on copper substrates

The growth characteristics of titanium films deposited on glass, silicon (100) and oxygen free high purity copper substrate using magnetron sputtering have been investigated using X-ray diffraction, electron microscopy and scratch indentation techniques. The study of interface between the titanium film and the substrate was carried out to determine coating thickness, as well as intermixing of the elements at the interface. Studies revealed that the interface is free from voids and intermixing of the film and the substrate. Microstructural and diffraction analysis showed that the Ti coating was polycrystalline and exhibited columnar growth. The Ti crystallite size varied between 24 and 58 nm depending on the substrate. The thickness of the films were typically about 4 μm. Scratch test indicated that the films are adherent and the first critical load to failure was observed to be 4·5 N ± 2 N.     

INVITED REVIEW STABILITY OF COLLOIDAL DISPERSIONS

The stability of colloidal dispersions has traditionally attracted considerable attention in the chemical literature because of its origins in the physical chemistry of electrostatic and steric interactions between surfaces immersed in liquids. Moreover, progress in the physics and chemistry of stability phenomena has a direct impact on chemical engineering research, since stability of dispersions plays an important role in the rheology and transport properties of charged particles in liquids, separation processes (such as membrane filtration and solid/liquid separation), deposition and particulale fouling phenomena and numerous other processing operations. This paper presents a discussion of physical and chemical factors that affect colloidal stability and, in addition, presents an overview of the status of current research needs in this area. In addition to electrostatic and steric effects, some recent studies on the role of bulk motion of the supporting liquid on stability are also discussed. The emphasis throughout is on the stability of dilute dispersions, in which simultaneous interactions between more than two particles are negligible. Some major research needs in the above areas are also identified.     

Balanced gait generations of a two-legged robot on sloping surface

In this paper, dynamically balanced gait generation problem of a 7-DOF two-legged robot moving up and down through the sloping surface is presented. The gait of the lower links during locomotion is obtained after assuming suitable trajectories for the swing leg and hip joint. The trunk motion is initially generated based on the concept of static balance, which is different from the well-known semi-inverse method and then checked for its dynamic balance calculated using the concept of Zero-Moment Point (ZMP). Lagrange–Euler formulation is attempted for the determination of joint torques. Average power consumption at each joint is then determined based on the computed torques. Moreover, the variations of dynamic balance margin and average power consumption are studied for both ascending and descending through the sloping surface. Both of them are found to be more for the ascending gait generation compared to those for the descending case. The effects of variations of the slope have also been studied on the average dynamic balance margin and power consumption for both the cases.     

Phenotypic and genotypic characterisation of Lactobacilli isolated from camel cheese produced in India

Thirty‐two Lactobacilli strains were isolated from four samples of camel cheese collected from Bikaner, India. These isolates were identified based on phenotypic and genotypic characteristics. Sequencing of 16S rDNA was performed for species identification and diversity analysis. Lactobacillus delbrueckii and Lb. fermentum were found to be dominant species followed by Lb. plantarum and Lb. casei. On evaluation of technological properties of these isolates, 20 isolates were observed to be good acid producers, eight were found positive for citrate utilisation and 11 showed presence of Prtp gene. Isolates obtained can be potential for development of defined strain starter for camel cheese.     

Inclusion of minority charge carriers in the solution of Poisson's equation for a metal semiconductor contact in thermal equilibrium†

A theory of the space-charge capacitance of a metal-semiconductor contact has been developed by solving the Poisson equation for the space-charge region under zero current condition. The space charge is assumed to consist not only of ionized donors and acceptors but also of electrons and holes. An explicit expression for the space-charge capacitance under those general conditions is given. In an appendix a procedure is outlined whereby the theory could be developed for the case of Fermi statistics with partially ionized donors.     

A method for unbalanced transportation problems in fuzzy environment

In this paper, we consider the fully fuzzy unbalanced transportation problem in which the total availability/production is more than the total demand and propose a method to solve it. Such problems are usually solved by adding a dummy destination. Since the dummy destination has no existence in reality, the excess availability is not transported at all and is held back at one or more origins. The method proposed in this paper gives the additional information that to which of the destination(s) the excess availability be transported for future demand at minimum cost. The advantage of the proposed method over the existing method is that the fuzzy optimal solution obtained does not involve the dummy destination. The method has been illustrated with the help of an example.