SHELF-LIFE MODELING OF SWEETENED CONDENSED MILK BASED ON KINETICS OF MAILLARD BROWNING

Nonenzymatic browning and related changes were monitored in commercial sweetened condensed milk stored at 7, 15, 30, 45 and 55C. Darkening of the color measured in terms of absorbance (100 - reflectance percent) followed zero-order kinetics, the apparent activation energy (E_a) being 45.2 kJ/mol at 7–30C and 139.9 kJ/mol at > 30–55C. Hydroxy-methyl-furfural (HMF) showed a first-order increase, the associated E_a values being smaller than those for absorbance. The pH exhibited a linear decline after a small initial rise at 30C and below. As browning progressed, the coffee whitening ability of the product decreased along zero-order kinetics. The Q₁₀ values for these variables ranged from 1.21 to 1.84 for temperatures up to 30C and were nearly 2–3 times higher above 30C. The sensory color score was negatively correlated with absorbance. The linear regression of color score on absorbance and the temperature dependence of the latter as expressed by Arrhenius relationship were combined into a mathematical model which could be useful in predicting the product's shelf-life.     

Influence of the coupling agent and graphene oxide on the thermal and mechanical behavior of tea dust–polypropylene composites

In this study, the effects of a coupling agent and additive on the physicomechanical (morphological, mechanical, thermal, and swelling) properties of tea dust (TD)–polypropylene (PP) composites were studied. TD–PP composites were prepared with untreated tea dust (UTD) and tetraethylsilane (TES)‐treated TD or silanated tea dust (STD) particles at ratios of 0:100, 10:90, 20:80, 30:70, and 40:60 w/w. Initially, TD particles were grafted by TES as a coupling agent, and these STD particles were then modified with graphene oxide (GO) as an additive to study their effects on the STD–PP composites; these were compared to the STD–PP and UTD–PP composites in accordance with a study of improvements in the mechanical properties. All of the TD–PP composites were analyzed with Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical, thermal, and physical tests. The thermal and mechanical properties of both the STD–PP and GO‐modified STD–PP composites were found to be improved as compared to those of the UTD–PP composites. So, the recycling of a large amount of TD as a waste material could be useful in the preparation of TD–PP composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42927.     

TMPTMA水溶性树脂及其涂料的研究

本文以丙烯酸烷基酯与丙烯酸进行溶液聚合，研究了聚合工艺及原料配比，以聚合树脂为基料制得涂料，并讨论了涂料的性能。     

Whipping test for the determination of foaming capacity of protein: a collaborative study

A standard whipping test, which involved preparing a 0.5% protein dispersion, whipping the dispersion in a Kenwood Chef food mixer and measuring the foaming properties (foam expansion, FE; foam volume stability, FVS; foam liquid stability, FLS) was collaboratively evaluated. A total of sixty determinations was made involving six laboratories, each of which analysed five samples in duplicate. The repeatability coefficient of variation ( CV ₀) in the estimation of FE and FVS properties of proteins was 6.25%. The reproducibility coefficient of variation ( CV _X) for FE and FVS was 9.8%, excluding the FE value (i.e. 20%) for spray-dried albumen. The CV ₀ and CV _X values for FLS properties of proteins ranged from 7.4 to 13.4% and 17.2 to 24.6%, respectively. Thus, FE, FVS and FLS properties can be used for intralaboratory comparisons (e.g. to determine batch-to-batch variation in commercial protein products), whereas FE and FVS values are more reliable for inter-laboratory comparisons of the foaming properties of proteins.     

Anti-static properties of some cationic polymers used in hair care products

Anti-static properties of cationic polymers on hair have been measured by using an electrostatic voltmeter. Comparisons are made with conventional cationic surfactants. Behaviour of cationic polymers from a cationic base and an anionic base have been explained. Experiments are performed to arrive at the hypothesis that cationic polymers form a complex with anionic detergent and that this cation-anion complex solubilizes in excess of anionic detergent, but on dilution with water it forms a turbid solution.
Propriétés anti-statiques de certains polymères cationiques utilisés dans les produits de soins pour les cheveux     

Firing scheme for pulse-width controlled AC-DC converters

A novel firing scheme is proposed for the control of pulse-width modulation type AC-DC converters. The firing circuit is capable of providing control both for rectifying and regenerative operations of the converters, for continuous as well as discontinuous conduction.     

The Impingement Heat Transfer Data of Inclined Jet in Cooling Applications: A Review

On the impingement heat transfer data, the experimental studies of air and liquid jets impingement to the flat surfaces were collected and critically reviewed. The oblique impingements of both single circular and planar slot jets were considered in particular. The review focused on the surface where the jet impingement cooling technique was utilized. The nozzle exit Reynolds numbers based on the hydraulic diameter varied in the range of 1,500–52,000. The oblique angles relative to the plane surf...     

Electronic properties and charge density of Be x Zn1 − x Te alloys

Electronic band structure calculations are performed for the Be _x Zn_1???x Te (0≤x≤1 in steps of 0·2) alloys following the empirical pseudopotential method. The alloying effects are modelled through the modified virtual crystal approximation. Throughout the composition, valence band maximum resides at the Γ point. The conduction band minimum, however, shifts from Γ to X point of symmetry when x?= 0·27. The observed crossover from direct to indirect bandgap is well in accordance with the experimental observations. Effect of alloying on the density of states is also discussed. The charge density distribution along a few major planes is computed and discussed. The electronic band structure related parameters like bandwidths, bandgaps and ionicity are reported and compared with experimental data wherever available. We also give estimates of cohesive energy and bulk modulus for the alloys.     

ZnO nanostructure thin films by continuous spray pyrolysis using doped precursor for Si solar cell application

This work presents deposition of Zn solution seed layer assisted growth of zinc oxide (ZnO) nanostructure layers by continuous spray pyrolysis reactor using lanthanides (Er and Eu) and metal (Al) influenced zinc acetate precursor solution. Dopants in precursors have influenced structural property, surface morphology and optical reflectance of resulting ZnO thin films which are supported by X-ray diffractometer, scanning electron microscope and reflectance measurements. Enhanced dispersion amongst nanorods is observed under the influence of Er and Al dopant in ZnO thin film. The change of precursor from Zinc acetate to Titanium tetraisopropoxide for Er doped precursor is helping to achieve better crystalline ZnO nanorods arrangement with increased homogenous growth, which results into improved light reflectance reduction of thin film. The experimental evidences of light reflectance from ZnO nanorods on Si surface is studied with the help of FDTD based Lumerical software package which can be a useful study for designing ZnO nanorods thin film in device purposes. The utility of ZnO layer by this reactor on low efficiency Si solar cell is also explored in improving device efficiency via increase of photocurrent.