Optimization of the continuously extruded unleavened flat bread (chapati) process

Processing variables such as size of die openings, production rate and initial moisture content on the discharge temperature and power input used in the continuous production of Indian unleavened flat bread (chapati) were studied. The extruder was a specially designed continuous chapati making system. The net specific energy (NSE) decreased with increasing size of die openings and moisture content. The total power efficiency increased with increasing production rate while NSE values remain unchanged. The discharge temperature decreased with increased moisture content of the dough and increased die opening size. The process variables were optimized for the continuous production of chapati, based on minimum specific energy and maximum puffing index. The optimum conditions were found to be a rate of 40 kg/h, a die opening of 1.4 mm height쐘 mm width and moisture contents of 60% and 75% (w.b.) for Resultant Atta and Atta, respectively. Sensory analysis showed that chapatis produced under the above conditions compared well with traditionally made chapatis in quality.     

Equations for nucleation of hydrogen gas pores during solidification of aluminium seven weight percent silicon alloy

A statistical prediction model has been applied to the nucleation rate as a function of temperature for an Al7Si alloy based upon observations of pore formation during solidification in an XTGS. A normalised Gaussian function was developed ((1), (2), (3) and (4)) which may be used to describe pore nucleation in mathematical simulations of porosity formation during solidification.     

Evaluation of the methods for calculating the concentration-dependent diffusivity in binary systems

Boltzmann and Matano developed a procedure for the solution to Fick’s second law when the diffusivity is a function of concentration. The procedure requires the determination of the so-called Matano interface. The accuracy of the resulting solution depends heavily on the precise location of the Matano interface, the determination of which is laborious and often inaccurate. Three alternative procedures by Sauer and Freise, Wagner, and den Broeder, modifications to the original Boltzmann-Matano (B-M) method, were developed such that the diffusivity can be calculated without having to determine the location of the Matano interface. However, none of these derivations quantifies the extent to which the modified methods arrive at the same result as that obtained from the standard B-M analysis. This article serves to apply the B-M method, and the modification suggested by den Broeder, to various analytical concentration profiles containing different degrees of noise and to compare the results quantitatively. In addition to these analytical functions, concentration profiles obtained from interdiffusion experiments were studied. The two methods are shown to be equivalent in terms of the accuracy of the result. The advantages or disadvantages of one method over the other are illustrated with examples.     

Effect of ionizing radiation on antinutritional features of velvet bean seeds (Mucuna pruriens)

Impact of gamma irradiation on the antinutritional constituents of seeds of Mucuna pruriens was assessed on exposing to doses of 2.5, 5.0, 7.5, 10, 15 and 30 kGy. Except for 2.5 kGy, the rest showed significant dose-dependent increase in phenolics. Tannin concentration did not differ significantly up to 7.5 kGy, while it significantly increased at higher doses. Excluding 2.5 kGy, the rest of the treatments showed significant decreases in the phytic acid and complete degradation was attained at 15 and 30 kGy. The l-DOPA concentration showed a dose-dependent decline. A trace amount of hemagglutination activity was seen on human erythrocytes in raw seeds, which was completely absent on irradiation (>5 kGy). Concentration of Polonium-210, a natural radionuclide falls within the admissible limits for consumption. As Mucuna seeds serve as food, feed or as pharmaceuticals, it may be necessary to set the ionizing radiation to a specific dose to retain optimum levels or to eliminate phenolics, tannins, phytic acid and L-DOPA. As irradiation is a physical and cold process, it may be ideal and emerge as an important technique to improve the nutritional or pharmaceutical quality of Mucuna seeds and its products.     

Development of male contraceptive vaccine--a perspective

Anti-disialoganglioside (GD2) monoclonal antibodies (MAbs) have been used in vivo for immunolocalization and in phase I and II trials to target disseminated neuroblastoma, the most common extracranial solid tumor in children. However, the efficacy of these first-generation MAbs is likely to be improved by using engineered anti-GD2 antibodies. The generation of single-chain antibody fragments (scFv) could be very helpful as these molecules can be further modified to produce recombinant molecules with pre-defined properties such as immunotoxins, chimeric, or bispecific antibodies. Thus, a scFv directed against GD2 (scFv 7A4) was cloned, sequenced, and expressed. Its binding properties were characterized and compared to that of the parental MAb 7A4. Nucleotide sequence analysis of the scFv 7A4 indicated that its VH region belongs to the V region IIID subgroup and the V kappa to the V region II subgroup. The scFv 7A4 bound to GD2+ neuroblastoma cell lines but not to GD2- cell lines or to GD2- cells isolated from peripheral blood. ELISA and thin-layer chromatography (TLC) indicated that it retained the anti-GD2 specificity, and exhibited a slight cross-reaction with GD3 as the parental MAb. This scFv makes it possible to develop new useful reagents through genetic engineering for adjuvant tumor therapy.     

Photo-acoustic imaging of surface acoustic wave slowness using multiplexed, two-wave mixing array interferometry

A method to rapidly measure the group velocities (or their inverse, slownesses) of surface acoustic waves (SAWs) in anisotropic materials is presented. Surface acoustic waves are generated using a pulsed laser focused to a point on a test object. A newly developed multiplexed two-wave mixing (MTWM) interferometer is used to simultaneously detect the SAW displacements along eight different directions using a circular array of detection points. The group velocity slowness curve is obtained directly from the measured signals from the MTWM array. The experimental results are compared to theoretical predictions in aluminum, silicon, and quartz.