J-CHART METHOD IN DESIGNING A PARTIALLY SOLAR HEATED DRYER

A new chart of simulation method, named J-chart, has been developed for predicting the long-term average performance of solar drying systems. The result of many simulations allows to develop a simple graphical method, represented by 3 charts and their polynomial correlations, to obtain a general design procedure for a partially solar heated dryer. The first one is the drying time, the second one is the fraction of heating load supplied by solar energy and the third one is the fraction of economized energy. These charts and the correlations are used in establishing relationships between the collector area and the weight of the produce to be dried or the dried produce. This method is developed by using the monthly average values for a moderate climate (Perpignan, Φ = 42.41^°) and with the assumption that the dryer is used daily over a year and the duration of drying operation is assumed to be less than 24 hours.     

Crystallography of dispersed liquid crystalline phases studied by cryo-transmission electron microscopy

Low molecular weight surfactants, for example monoglycerides and phospholipids, form a multitude of self‐assembled structures, such as inverted cubic or hexagonal mesophases, if brought into contact with water/oil. These mesophases can be dispersed in water using adequate surface‐active materials such as low molecular weight surfactants or surface active polymers. In order to use such mesophase particles for incorporating drugs and aromas, it is essential to determine their internal crystallographic structure and to understand their mechanism of stabilization. Cryo‐transmission electron microscopy was used to investigate the internal structure of different dispersed particles at various temperatures and oil contents. It is shown here that cryo‐transmission electron microscopy, in combination with fast Fourier transform and tilting experiments, is effective in obtaining information on crystallographic structure, space group and morphology of particles with reversed bicontinuous cubic and hexagonal structures. In particular, using the presence or the absence of the {111} reflections and viewing the same particle under different axes of observation allows one to discriminate between the Im3m and Pn3m space groups. A major advantage of cryo‐transmission electron microscopy is the ability to analyse single particles. This allows the identification of particles present at very low concentrations and the coexistence of particles with different internal self‐assembly structures. With this technique we have obtained strong evidence for the presence of two cubic internal self‐assembly structures with different space groups within the same dispersion. In addition, we found that cryo‐transmission electron microscopy combined with tilting experiments enables the analysis of internal particle morphology, allowing the discussion of mechanisms for hexosome stabilization.     

Pilot scale preparation of wheat gluten protein fractions I-Influence of process parameters on their protein composition

Commercial wheat gluten was fractionated on a pilot plant scale to produce gliadin-and glutenin-rich fractions. Acetic acid solutions (0.01–0.05 M) were blended with dry gluten (16, 10 or 7 volumes unit^-1 of dry gluten ratio) and the slurry was separated by continuous centrifugation to yield a gliadin-rich supernatant, which was then concentrated by ultrafiltration and spray-dried. the pellet obtained was optionally rinsed by water or acetic acid and separated in a second stage. the second supernatant was treated as the first one, and the final residue, insoluble and glutenin-rich, was then dispersed in ammonia and spray-dried. the protein distributions in supernatants and residues depended on pH and ranged from 20/80 to 40/60 for the first stage, and from 40/60 to 80/20 for the sum of the two stages. the compositions of the fractions were measured by solubility tests and size exclusion high performance liquid chromatography (SE-HPLC) profiles. A [-1, +1] selectivity scale was created: each fraction was compared to pure gliadins (-1), gluten (0) and pure glutenins (+1). the best combination between yields of soluble and insoluble fractions (40/60 distribution) and selectivities for gliadins and glutenins (-0.32 and +0.26 respectively) was obtained at ratio 16 and a 0.01 M molarity. Though the selectivities were limited because gliadins and medium-size glutenin polymers have similar solubilities in acid solutions, this process permits preparation of fractions which differ widely from gluten in contents of high molecular weight glutenin polymers.     

Ni-基超合金等离子体辅助渗氮过程中的应力诱发各向异性扩散

在对Ni-基超合金Inconel 690进行等离子体辅助渗氮处理过程中观察到了一个特殊的现象,即氮在该合金中的扩散呈各向异性,不同取向的晶粒其渗氮层厚度是不同的,并且氮在取向接近(100)的晶粒内比在取向接近(111)的晶粒内的扩散要快.以渗氮过程中应力和应变的各向异性为基础建立了一个模型对上述现象进行了解释.在这种具有面心立方结构的合金中,由于应力的各向异性导致了氮元素在不同晶体取向上的扩散激活能是不同的,并最终导致了氮在该合金中的各向异性扩散现象.在低于400℃的温度下根据该模型计算得到的结果与实验结果吻合的较好.     

Cloning of the Multicopy Suppressor Gene SUR7: Evidence for a Functional Relationship between the Yeast Actin-binding Protein Rvs167 and a Putative Membranous Protein

The rvs161 and rvs167 mutant cells exhibit several identical phenotypes including sensitivity to several different growth conditions and morphological defects such as alteration of the actin cytoskeleton and budding patterns. The selection of genes that, when overexpressed, are able to suppress the reduced viability upon carbon starvation of the rvs167 mutant strain, has allowed the cloning of the SUR7 gene (Accession Number Z46729x11). We showed that the suppressive ability of the overexpressed SUR7 gene concerns all the rvs167 phenotypes. However, this suppression is only partial since the rvs167-suppressed strain is not of wild-type phenotype. Moreover, SUR7 is also able to suppress partially the phenotypes exhibited by the rvs161 and rvs167 rvs161 mutant strains. The SUR7 gene encodes a putative integral membrane protein with four transmembrane domains. Furthermore, sequence comparisons revealed that Sur7p and two other proteins, Ynl194p and Ydl222p, present significant sequence and structural similarities. Taken together, these results strongly suggest that the Rvs161 and Rvs167 proteins act together in relation with Sur7p. Moreover, the putative transmembranous character of Sur7p suggests a membrane localization of the Rvs function, a localization which is consistent with the different rvs phenotypes and the actin–Rvs167p interaction. © 1997 John Wiley & Sons, Ltd.     

REDUCED COMPLEXITY FREQUENCY ESTIMATOR FOR BURST TRANSMISSION

In burst transmission, carrier recovery is a critical point for synchronization systems. With a feedforward carrier phase recovery algorithm, a small frequency offset can significantly increase the cycle slip rate and then the phase error variance. Therefore, in order to obtain an accurate carrier phase estimation, a precise frequency correction is required. For M-states phase shift keying (M-PSK) modulated signals an unbiased feedforward reduced complexity frequency estimator (RCFE), operating in the non-data aided mode (NDA) is derived from the maximum likelihood (ML) principle. A compromise is realized between noise filtering and estimation slip probability by minimizing the estimator variance. It is optimized to operate at a low signal-to-noise ratio and short bursts. Its performance is compared to that of the ML estimator. The estimator is applied to an all-feedforward synchronization structure with QPSK modulated signals. Global performance of the modem synchronization structure is supplied. © 1996 by John Wiley & Sons, Ltd.     

FLASH DISCHARGE OF SUPERCRITICAL FLUID AND HIGH PRESSURE GAS THROUGH PIPES: EXPERIMENTAL RESULTS AND MODELLING

Although the flash discharge of a supercritical fluid is of key importance for the safe design of safety valves and effluent lines, very few experimental and theoretical results have been obtained in the literature. In this paper is reported a systematic experimental study concerning the flash discharge of supercritical and gaseous Co₂, and gaseous N₂ under different conditions: temperature, pressure and mass of fluid, diameter and length of discharge pipes. The discharge flux can reach as high as 30000 kg. m^?2 ·s^?1 A theoretical model is developed for predicting the variation of fluid mass and other parameters during a discharge, and found to agree with observations to a first approximation.     

Heterogeneity, nucleation, shrinkage and bloating in sol–gel glass ceramics (the case of lithium aluminosilicate compositions)

Sintering of sol–gel powders often leads to porous samples despite the high reactivity of such powders. The influence of heterogeneity coming firstly from the use of different reagents as gel formers (Si and Al alkoxides) or of a mixed nature (Si–Al ester) and secondly from the hydrolysis–polycondensation route (mixing in anhydrous condition or pre-hydrolysis of the reagents) was studied for a lithium aluminum silicate composition using differential thermal analysis, expansion-shrinkage measurements and X-ray diffraction. The effects of the synthesis conditions on the microstructures is discussed from optical microscopy, scanning electron microscopy and metallurgical observations.     

CHEMICAL COMPOSITION OF OIL FROM TETRACARPIDIUM CONOPHORUM ((MÜLL. ARG.) HUTCH. AND DALZ.) NUTS

Tetracarpidium conophorum is known in the littoral and the western Cameroon as kaso or ngak and serves as an edible nut eaten between meals. The physicochemical characteristics, the fatty acids and the triacylglycerols (TG) of T. conophorum nut oil (Type 1 and Type 2) from the southern continental low lands were studied. The oil content varied between 55.75 and 61.62%. The iodine value (180–182), saponification value (175–176) and nitrogen (8.08–8.78) were similar. Ashes varied between 8.40 and 9.68%. The main fatty acid of the golden yellow was linolenic acid (69.47–70.39%) as determined by capillary gas chromatographic analysis. The triacylglycerol profil obtained by reversed phase liquid chromatography showed 10 TG with three major ones identified as