Effect of Baking Conditions on Properties of Starch Isolated from Bread Crumbs: Pasting Properties,Iodine Complexing Ability,and X-ray Patterns

In order to understand starch changes induced by baking process at different locations of a slice of sandwich bread, namely the top, center, and bottom locations, starch was isolated from crumbs baked at two heating rates ( 6.31 and 4.67 °C/min) and evaluated for their pasting properties, gelatinization parameters, and iodine complexing ability. Results showed that starch isolated from the bottom and the center crumbs baked at higher heating rate presented the significant higher final viscosity and higher setback than that isolated from crumbs baked at lower heating rate. Thermal analysis showed that starch isolated from the center crumb of the bread slice presented the lower enthalpy value of gelatinization, confirming that these samples underwent higher heat-moisture treatment during the baking process. After equilibration at 0.97 a_w, the exposure to iodine vapor changed the X-ray diffraction intensity of starch samples. Polarized light microscopy showed that heating affects starch granule morphology due to the higher starch chain mobility and the higher granular swelling when breads were baked at lower heating rate.     

Effect of blend proportion on moisture management characteristics of bamboo/cotton knitted fabrics

This study reports an investigation of the effect of the blend-ratio of bamboo and cotton fibres on the moisture management properties of single jersey knitted fabrics composed of them. The moisture management properties of the fabrics were measured in SDL-ATLAS moisture management tester. The liquid transport properties of textiles, such as wetting time, maximum moisture absorption rate, maximum wetted radii, spreading speeds, cumulative one-way transport capacity and overall moisture management capacity (OMMC), have been considered and correlated to the blend ratio of bamboo/cotton yarn single jersey knitted fabrics. It was observed that as the bamboo content increased, the wetting time decreased, maximum wetted radius decreased, rate of absorption increased, spreading speed decreased and OMMC decreased.     

Influence of blend ratio and linear density on liquid spreading characteristics of bamboo/cotton-blended yarn knitted fabrics measured by liquid spread tester

In this study, a new liquid spread tester, designed and developed in an earlier work by the authors, has been used for the study and analysis of the transverse wicking characteristics of single jersey-knitted fabric produced from bamboo/cotton-blended yarn. The most significant liquid spreading characteristic, namely the liquid spreading rate, has been measured and analysed for two sets of the knitted fabric composed of bamboo/cotton yarn, one of linear density Ne 20s and the other of Ne 40s yarn. The yarn blend composition was varied in a similar manner for both sets of fabric. It was observed that liquid spreading rate decreased with increase in bamboo content for all the blend proportions investigated. It was also found that this property is higher in the wale-way direction than the course-way direction.     

An integral approach for simulation of vapour film dynamics around a spherical surface

The dynamics of a thermally driven vapour film around a solid sphere has been investigated here with both the sphere and the annular film surrounded by a large water pool. Integral models based on constant and variable vapour-phase densities have been developed here for studying a spherico-symmetric phase change problem for two immiscible phases, vapour and liquid around a hot sphere. Governing equations for both liquid and vapour phases are converted into a set of non-linear ODEs. Effects of distinct density on interface condition and density variation of vapour phase are taken into account both in energy equation of vapour phase and also in interfacial mass and energy balance. The present models have been validated with available analytical, incompressible Volume of Fluid (VOF) and experimental results of growth and collapse of either bubble or vapour film. A simple model, based on scale analysis, was evolved that successfully captured the non-monotonic growth of the film, as observed by the more detailed models under certain degree of liquid subcooling. In addition, the case of very small thermal boundary layer in the liquid side has been successfully studied for which the VOF model required very fine grid. It has been observed that the effect of density variation in the integral model results in marginally higher film growth at higher temperature. However, the effect of radiation on the film growth was found to be quite substantial. The integral model not only incorporates the effects of vapour-phase temperature variation and radiation exchange of heat but also is computationally several-fold efficient with respect to the VOF model.     

Extrusion of Rice,Bean and Corn Starches: Extrudate Structure and Molecular Changes in Amylose and Amylopectin

The objective of this study was to evaluate the effects of starch source and amylose content on the expansion ratio, density, and texture of expanded extrudates, as well as to investigate the structural and molecular changes that occur in starch granules as a function of extrusion. The starches employed were rice starches (8%, 20%, and 32% amylose), carioca bean starch (35% amylose), and Hylon V^® corn starch (55% amylose). The extrudates from rice starches containing 20% and 32% amylose exhibited the highest expansion ratio, while, extrudates from Hylon V^® corn starch containing 55% amylose exhibited the lowest expansion ratio. The hardness values of the extrudates with 55% amylose were twice those of the extrudates with 20%, 32%, and 35% amylose. An additional finding was that although the amylopectin promoted the expansion of the gelatinized starch matrix, it failed to strengthen and sustain the walls of the extrudate bubbles during expansion.     

Effect of pre-mastication on dispersion of nanoclay in presence of carbon black in an inner liner compound: Studies on physicomechanical and functional properties

The present study demonstrates the use of “pre-mastication” technique for getting higher dispersion of organoclay, Cloisite 15A, in an inner liner compound based on 70:30 bromobutyl and natural rubber blend, in presence of higher concentration of carbon black (60 phr) for the improvement of functional properties like fatigue cut growth and air permeability resistance. Studies have showed that the organoclay was almost equally distributed within the blend both in absence as well as in presence of carbon black. The vulcanization curve showed a marked increase in cure acceleration as well as a significant rise in the maximum torque value because of higher crosslinking aided by the participation of the quaternary amine present in Cloisite 15A; however, in the carbon black loaded compound, the cure acceleration was not so pronounced because of engaging interaction between amine and functional groups of carbon black. The microscopic study revealed a good dispersion of Cloisite 15A within the elastomer blend- in presence of carbon black. The anisotropic platelets of Cloisite 15A and carbon black particles jointly formed “nano units”, which occluded a portion of elastomer segments vis-a-vis partial intercalation within the clay gallery. Such a reinforcing model was instrumental in improving the physicomechanical and functional properties under static and dynamic conditions. The organoclay displayed a much-improved properties at 2 and 4 phr doses in presence of 60 phr carbon black because of formation of enough “nano units” while deterioration was observed at 6 phr dose due to clay aggregation. Based on the results obtained on functional properties it was concluded that the 4 phr of organoclay compounded in “pre-mastication” mode delivered the best improvement and thus it was recommended for future up-scaling study.     

Temporal response of biochemical and biological sensors with bimodal surface adsorption from a finite sample

Microsystem Technologies - The importance of adsorption-based biochemical/biological sensors in biochemistry and biophysics is paramount. Their temporal response gives information about the...     

Thermal simulation of machining of alumina with wire electrical discharge machining process using assisting electrode

Journal of Mechanical Science and Technology - Electrical discharge machining or Wire electrical discharge machining have proven to be an alternate mean for machining nonconducting materials to a...     

Design and Flow Analysis of MEMS based Piezo-electric Micro Pump

Microsystem Technologies - Controlled drug delivery in medical application plays a prominent role, that can be achieved by micro-drug delivery devices. The efficient working of the controlled drug...