Obstruction Effect of Carrageenan and Gelatin on the Diffusion of Glucose

From an experimental set-up with boundary conditions of an extended initial distribution the diffusion coefficients for glucose in high K-content carrageenan gels and gelatin gels were determined as a function of polymer concentration. The data are evaluated according to the well-known equations on the conduction in heterogeneous systems. It is concluded that both hydrocolloids affect diffusion mainly because of an obstruction effect. In this phenomenon the contribution of the hydration sphere seems to be more important than the polymer itself. Hydrations are calculated to be about 5.0 and 1.90 grams of water per gram of dry polymer respectively for carrageenan and gelatin.     

MODEL CHECKING A KNOWLEDGE EXCHANGE SCENARIO

We are interested in applying model checking techniques to the verification of communication protocols that require safe communication. Typically, in such scenarios, one desires to demonstrate that one party can reliably communicate information to another party without a third party being able to determine this information. Our approach involves using the modal logic of knowledge, which has only relatively recently been studied in the context of security protocols. We demonstrate our approach by means of a detailed case study: the Russian cards problem. This is an example of a security protocol with nontrivial requirements on the knowledge of the agents involved. Using the Russian cards problem as an example, it is shown how the satisfaction of properties involving knowledge can be verified in a standard model checker, which in our case is SPIN.     

Processing Factors Influencing Splitting and Other Quality Characteristics of Canned Kidney Beans

Single factor changes from a standard canning process indicated that significant reductions in splitting resulted from higher soak Ca concentrations, higher soak temperatures, higher brine Ca concentrations, and shorter cooking times. Splitting in canned kidney beans was markedly reduced by soaking beans before cooking at temperatures of 66–71°C in solutions containing 150–350 ppm CaCl₂. Treatments giving lower gain in weight during soaking led to less splitting. Lower splitting was associated with lower drained weight and firmer cooked beans.     

COMPARISON OF FORCE-DEFORMATION CHARACTERISTICS OF ARTIFICIAL AND SEVERAL NATURAL FOODS FOR CHEWING EXPERIMENTS

The masticatory performance of an individual has been quantified by determining the particle sizes of the comminuted food. Optosil, a silicon rubber, has been used as an artificial test food in clinical studies, because it has reproducible textural properties. A comparison between Optosil and several natural foods was made by measuring textural properties of Optosil, turnip, carrot, Gouda cheese and peanut. Several types of probes were used to imitate the cusp form of the teeth. Force-deformation plots revealed similar maximum firmness for Optosil, turnip and carrot, whereas peanut showed a larger firmness. The force needed to crush Optosil is much larger than for the natural foods, but it is well within the physiological range of healthy subjects. The reproducibility of the textural properties is better for Optosil than for the natural foods. The particle size distribution of Optosil broken by a testing machine was compared with the results obtained during chewing.     

含氧化锆的氧化物系统计算相图研究与进展

氧化锆是一种重要的高性能陶瓷材料，由于其优良的力学和电学性能。在结构陶瓷和功能陶瓷两个都有着广泛的应用前景，本文在简述计算相图发展和原理的基础上，综述了近年来对含氧化锆系统计算相图的研究，总结了一些重要体系的研究结果，提出计算相图方法将对该系统材料的组分设计起重大的促进作用。     

Smart structures and their applications on active vibration control: Studies in the Department of Aerospace Engineering, METU

This work presents the theoretical and experimental studies conducted in Aerospace Engineering Department of Middle East Technical University on smart structures with particular attention given to the structural modelling characteristics and active suppression of in-vacuo vibrations. The smart structures considered in these analyses are finite and flat aluminium cantilever beam-like (called as smart beam) and plate-like (called as smart fin) structures with surface bonded lead–zirconate–titanate patches. Finite element models of smart beam and smart fin are obtained. Then the experimental studies regarding open loop behaviour of the structures are performed by using strain gauges and laser displacement sensor to determine the system models. Further studies are carried out to obtain H _∞ and μ-synthesis controllers which are intended to be used in the suppression of free and forced vibrations of the smart structures. It is observed that satisfactory attenuation levels are achieved and robust performance of the systems in the presence of uncertainties is ensured. In that respect a comparative study involving H _∞ and sliding mode controls is also conducted. Recently, the studies involving aerodynamic loading are also gathering pace.     

On the wind energy resources of Sudan

The imminent exhaustion of fossil energy resources and the increasing demand for energy were the motives for those reasonable in Sudan to put into practice an energy policy based on rational use of energy; and on exploitation of new, and renewable energy sources. After 1980, as the supply of conventional energy has not been able to follow the tremendous increase of the production demand in rural areas of Sudan, a renewed interest for the application of wind energy has shown in many places. Therefore, the Sudanese government began to pay more attention to wind energy utilisation in rural areas. Because the wind energy resource in many rural areas is sufficient for attractive application of wind pumps, and as fuel is insufficient, the wind pumps will be spread on a rather large scale in the near future. Wind is a form of renewable energy, which is always in a non-steady state due to the wide temporal and spatial variations of wind velocity. A number of years worth of data concerning wind speed in Sudan have been compiled, evaluated and presented in this article. The need for the provision of new data stations in order to enable a complete and reliable assessment of the overall wind power potential of the country is identified and specific locations suggested. This paper presents the background and ideas of the development of the concept as well as the main results, and experience gained during ongoing project up to now. In Sudan, various designs of wind machines for water pumping have been developed and some designs are presently manufactured commercially. Results suggest that wind power would be more profitably used for local-and small-scale applications especially for remote rural areas. It is concluded that Sudan is blessed with abundant wind energy.     

Methods to calibrate and scale axial distances in confocal microscopy as a function of refractive index

Accurate distance measurement in 3D confocal microscopy is important for quantitative analysis, volume visualization and image restoration. However, axial distances can be distorted by both the point spread function (PSF) and by a refractive‐index mismatch between the sample and immersion liquid, which are difficult to separate. Additionally, accurate calibration of the axial distances in confocal microscopy remains cumbersome, although several high‐end methods exist. In this paper we present two methods to calibrate axial distances in 3D confocal microscopy that are both accurate and easily implemented. With these methods, we measured axial scaling factors as a function of refractive‐index mismatch for high‐aperture confocal microscopy imaging. We found that our scaling factors are almost completely linearly dependent on refractive index and that they were in good agreement with theoretical predictions that take the full vectorial properties of light into account. There was however a strong deviation with the theoretical predictions using (high‐angle) geometrical optics, which predict much lower scaling factors. As an illustration, we measured the PSF of a correctly calibrated point‐scanning confocal microscope and showed that a nearly index‐matched, micron‐sized spherical object is still significantly elongated due to this PSF, which signifies that care has to be taken when determining axial calibration or axial scaling using such particles.     

Deposition and Characterization of Si Substituted Cu2ZnSnS4 Thin Films

Silicon - The influence of the Si substitution ratio on the structural, morphological, and optical properties of Cu2ZnSnS4 (CZTS) thin films was examined. The Cu2Zn(SixSn1–x)S4 thin films...