Stabilization of poly(vinyl chloride) by elemental sulfur

The process of stabilization of a poly(vinylchloride) elemental sulfur in thermal and thermooxidative destruction conditions is investigated. The high stabilizing efficiency of elemental sulfur is revealed at the destruction of plasticized poly(vinylchloride) compared with the efficiency of phenolic antioxidants. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

COMPARING PRONOUN RESOLUTION ALGORITHMS

This paper discusses the comparative evaluation of five well-known pronoun resolution algorithms conducted with the help of a purpose-built tool for consistent evaluation in anaphora resolution, termed the evaluation workbench. The workbench enables the evaluation and comparison of pronoun resolution algorithms on the basis of the same preprocessing tools and test data. The tool is controlled by the user who can conduct the evaluation according to a variety of parameters, with regard to the types of anaphors and the samples used for evaluation. The extensive comparative evaluation of the pronoun resolution algorithms showed that their performance was significantly lower than the figures reported in the original papers describing the algorithms. The evaluation study concluded that the main reason for this drop in performance is the fact that all algorithms operate in a fully automatic mode.     

Preliminary results of a V-groove back-pass solar collector

The study conducted by the Solar Energy Research Group, Universiti Kebangsaan Malaysia shows that solar energy has a great potential to be used in drying processes. A prototype solar drying system was designed and tested in the campus (Othman et. al, 1994). The study shows that the system can be upgraded by improving the solar collector. This paper presents the preliminary result on the performance of the V-groove back-pass solar collector modified from V-groove double flow solar collector designed earlier (Othman et. al, 1992). The results shows that the collector maintained the output temperature eventhough there are changes of solar radiation intensity. At 0.65 ms⁻¹ air flow rate, the output temperature of the collector can manage to maintain 40°C in the range of solar intensity of 800 Wm⁻² to 300 Wm⁻² within 15 minutes time interval, and at 0.45 ms⁻¹, the output temperature is 43°C in the range of solar intensity of 800 Wm⁻² to 600 Wm⁻². The min daily efficiency of 20% is recorded at 450 Wm⁻² of min daily solar radiation at 0.65 ms⁻¹ flow rate. At 0.45 ms⁻¹ flow rate with the equal amount of daily min solar radiation the min daily efficiency is 13%. The result is expected to be better if the study is conducted in May - June when the weather is better.     

Asynchronous sum‐of‐products logic minimization and orthogonalization

We propose a method of the asynchronous sum‐of‐products (SOP) logic simplification that comprises of minimization and orthogonalization. The method is based on a transformation of the conventional single‐rail SOP synchronous logic into the dual‐rail asynchronous one operating under so‐called modified weak constraints. We formulate and prove the product terms constraint that ensures a correct logic behavior. We have processed the MCNC benchmarks and generated the asynchronous SOP logic. The complexity of the logic obtained is compared with the state‐of‐the‐art representation. Using our approach, we achieve a significant improvement. Copyright © 2012 John Wiley & Sons, Ltd.     

Collagen from porcine skin: a method of extraction and structural properties

This paper presents a study of the processing of collagen-containing raw material and its changes in the course of targeted complex processing by hydrolysis, including freeze-drying. The pH, chemical composition, penetration magnitude, and critical shear stress were determined. The dried samples were examined using Fourier-transform infrared spectroscopy, and their microstructures were characterized. The characteristic property of the product developed was determined to be the presence of a relatively homogeneous fibrillar structure that promotes the functional capacity of the proteinoid-forming fibres in the compositions of foods from different groups.     

Unfolding and Aggregation of Lysozyme under the Combined Action of Dithiothreitol and Guanidine Hydrochloride: Optical Studies

Using a number of optical techniques (interferometry, dynamic light scattering, and spectroscopy), denaturation of hen egg white lysozyme (HEWL) by treatment with a combination of dithiothreitol (DTT) and guanidine hydrochloride (GdnHCl) has been investigated. The denaturing solutions were selected so that protein denaturation occurred with aggregation (Tris-HCl pH = 8.0, 50 mM, DTT 30 mM) or without aggregation (Tris-HCl pH = 8.0, 50 mM, DTT 30 mM, GdnHCl 6 M) and can be evaluated after 60 min of treatment. It has been found that denatured by solution with 6 M GdnHCl lysozyme completely loses its enzymatic activity after 30 min and the size of the protein molecule increases by 1.5 times, from 3.8 nm to 5.7 nm. Denaturation without of GdnHCl led to aggregation with preserving about 50% of its enzymatic activity. Denaturation of HEWL was examined using interferometry. Previously, it has been shown that protein denaturation that occurs without subsequent aggregation leads to an increase in the refractive index (Δn ~ 4.5 × 10⁻⁵). This is most likely due to variations in the HEWL–solvent interface area. By applying modern optical techniques conjointly, it has been possible to obtain information on the nature of time-dependent changes that occur inside a protein and its hydration shell as it undergoes denaturation.     

Grain Boundaries and Mechanical Properties of Ultrafine-Grained Metals

The concept of grain boundary (GB) engineering of ultrafine-grained (UFG) metals and alloys is developed for enhancement of their properties by tailoring different GBs (low-angle and high-angle ones, special and random, or equilibrium and nonequilibrium) and formation of GB segregations and precipitations by severe plastic deformation (SPD) processing. In this article, using this approach and varying regimes and routes of SPD processing, we show for several light alloys (Al and Ti) the ability to produce UFG materials with different GBs, and this can have a dramatic effect on the mechanical behavior of the processed materials. This article demonstrates also several new examples of attaining superior strength and ductility as well as enhanced superplasticity at low temperatures and high strain rates in various UFG metals and alloys.     

Review of solar assisted heat pump drying systems for agricultural and marine products

Combining solar energy and heat pump technology is a very attractive concept. It is able to eliminate some difficulties and disadvantages of using solar dryer systems or solely using heat pump drying separately. Solar assisted heat pump drying systems have been studied and applied since the last decades in order to increase the quality of products where low temperature and well-controlled drying conditions are needed. This paper reviewed studies on the advances in solar heat pump drying systems. Results and observation from the studies of solar assisted heat pump dryer systems indicated that for heat sensitive materials; improved quality control, reduced energy consumption, high coefficient of performance and high thermal efficiency of the dryer were achieved. The way forward and future directions in R&D in this field are further research regarding theoretical and experimental analysis as well as for the replacement of conventional solar dryer or heat pump dryer with solar assisted heat pump drying systems and solar assisted chemical and ground source heat pump dryers which should present energy efficient applications of the technologies.