Potential of using plant proteins and chicken feathers for cotton warp sizing

Two plant proteins, soyprotein and wheat gluten, and chicken feathers used to size cotton substrates provided sizing performance similar to starch and were also easily degraded in activated sludge. Sizing is an essential process to impart protection to warp yarns and increase weaving efficiency. Cotton yarns have traditionally been sized with starch, modified starch derivatives, CMC, poly vinyl alcohol (PVA), or a combination thereof along with quite a few other fiber binding ingredients. Although starch and starch derivatives are extensively used for sizing, there can be several limitations including less-than-satisfactory sizing performance and difficulties in desizing starch based size. Plant proteins such as wheat gluten, soyproteins and poultry feathers are available in large quantities at low cost and have limited industrial applications. However, these proteins are known to have excellent film-forming properties, a primary requirement for a warp size, and have also been used as adhesives. Using proteins as warp sizing agents on cotton yarns potentially could provide acceptable sizing performance and be cost-effective, as well. In this research, soyproteins, wheat gluten, and chicken feathers were studied for exploring their feasibility for sizing, desizing, biodegradability, and ability to replace starch and PVA for sizing cotton yarns. It was found that all three proteins provided similar cohesion to fibers and abrasion resistance compared to starch. Protein sizes had significantly high BOD₅/COD ratio compared to PVA, suggesting that the proteins are easily degradable in textile effluent treatment plants.     

Synthesis and characterization of 6-alkylcarbamato-2, 10-dichlorodibenzo [d,g] [1,3,6,2]dioxathiaphosphocin 6-oxides

Novel 6-alkylcarbamato/thiocarbamato-2,10-dichlorodibenzo [d,g][1,3,6,2]dioxathiaphosphocin 6-oxides were synthesized by cyclization of 5,5′-dichloro-2,2′-dihydroxydiphenyl sulfide with the corresponding dichlorophosphinyl carbamates/thiocarbamates that were obtained by the addition of alcohols/thiols to dichloroisocyanatophosphine oxide and were characterized by IR, ¹H, ¹³C, ³¹P NMR, and mass spectral studies. A ¹³C NMR analysis revealed ²J_POC and ³J_POCC couplings. © 1996 John Wiley & Sons, Inc.     

Effect of Electric Field on Dielectric Properties of SnO2 Sb2O3 and their Mixed Thin Films

Thin films of various thicknesses in the MIM structure have been prepared from the the powders of SnO₂, Sb₂O₃ and (SnO₂ + Sb₂O₃) of high purity by the thermal evaporation technique in a vacuum of 10⁻⁵ Torr. Dielectric properties of SnO₂, Sb₂O₃, and their mixed thin films have been studied with ac and dc electric fields and frequency. Capacitance and loss tangent are almost independent on dc voltage upto 1.0 V for SnO₂, 10.0 V for Sb₂O₃ and 2.5 V for mixed films. These capacitors become unstable at 1.0 V for SnO₂ films and 2.5 V for mixed films. For higher film thicknesses the decay in these films starts at higher voltages. Capacitance and loss tangent increases with applied ac voltage in SnO₂, Sb₂O₃, and their mixed films. A comparison of the capacitance values of SnO₂, Sb₂O₃, and their mixed films showed that the capacitance values are less in Sb₂O₃ as compared to SnO₂ films. In mixed films the capacitance is greater than the constituent films. These studies have shown that Sb₂O₃ films are found to be more stable compared to SnO₂ and their mixed films for ac and dc voltages. The results thus obtained on SnO₂, Sb₂O₃, and their films are presented and discussed.     

Instantaneous work hardening behaviour of two-phase tungsten heavy alloys: a phenomenological approach

ABSTRACT

The present work describes a phenomenological approach to explain the instantaneous behaviour of tungsten heavy alloys (WHAs) in heat-treated and swaged conditions. The strengths and elongation values of heat-treated materials are lower and higher than those of the swaged samples respectively. The heat-treated materials exhibit two slopes in true stress–true plastic strain curves and follow the Ludwigson constitutive equation. On the other hand, swaged materials display a single slope and adhere to typical Swift constitutive equation. The latter reflect the presence of pre-strain in the materials due to swaging deformation. The fracture surfaces in heat-treated materials consist of W-W decohesion along with matrix rupture and W-cleavage, while swaged samples consist of mainly W-cleavage. Both the materials display three typical stages (I, II and III) of work hardening. The second derivatives of true stress–true plastic strain curves of these alloys exhibit a perfect parabola although the nature of true stress–true strain as well as true stress–true plastic strain curves is quite different in heat-treated and swaged materials. This has been observed for the first time in WHAs consisting of matrix and W-grains. The shape of the parabola is simple and easy to fit. The fitting parameters of parabolas have been successfully employed to explain the flow behaviour of a large number of tungsten heavy alloys having two-phase microstructure in different processing conditions.     

Role of Impurity Precipitates on Microhardness of KBr:Ba2+ Crystals

Microhardness of KBr crystals doped with various concentration of Ba²⁺ have been investigated in the asgrown state and after quenching from various elevated temperatures. It is observed that hardness increases with increase in impurity concentration and at high concentration the hardness starts decreasing. Microstructural investigations have showed the formation of visible precipitates at high concentrations. The heat treatment studies showed that in crystals quenched from elevated temperatures the visible precipitates dissociate and hardness increases.     

Thermoluminescence studies of Al2O3 crystals doped with Cobalt impurity

Thermoluminescence (TL) studies of cobalt-doped Al₂O₃ crystals irradiated with X-rays have shown that the TL glow curve consists of three peaks at 105, 195 and 260°C. Bleaching, annealing and quanching studies have been performed in order to understand the nature of colour centers responsible for the formation of the three peaks. The values of the fundamental parameters like trap depth and frequency factor are estimated from TL data and the results obtained are discussed.