Characterization of High-amylose Type Endosperm Starches of Rice Plants Cultivated in Asia

Starch granules were prepared from 14 indica rice grains which were collected from various places of Asia and had the amylose content of 28% and over by a blue value method. The starches were high- and medium-amylose types by the enzymatic and chromatographic method. However, none of them belonged to the type of high amylose mutants which were induced by the chemical mutagen treatment of a japonica rice cultivar: Kinmaze and possessed similar characteristics of endosperm starch to that of the amylose-extender (ae) mutant of maize (Zea mays L.).     

DSC Characteristics of Gelatinization of Starches of Single-, Double-, and Triple-Mutants and Their Normal Counterpart in the Inbred Oh43 Maize (Zea mays L.) Background

Starch granules were isolated from mature kernels of single-, double-, and triple-mutants of endosperm starch modifying genes [waxy(wx), dull(du), amylose extender(ae), sugary-2(su₂)] and their normal counterpart in the inbred Oh43 maize (Zea mays L.) background. Gelatinization characteristics of the starch granules were investigated by means of differential scanning calorimetry (DSC). The onset, peak, and conclusion temperatures of gelatinization (To, Tp, and Tc, respectively) and the heat of gelatinization (ΔH) of starch were determined from the DSC thermograms. The Tc of wx was higher than normal starch, and the ΔH of wx was larger than normal starch. The Tp and Tc values of ae starch were the highest. The To, Tp, and Tc values of su₂ starch were low. The noticeable effects of each of the wx, ae, and su₂ genes on To, Tp, Tc and ΔH were observed in starches of their respective mutant combinations. Apparent epistatic effects of the genes for gelatinization temperature were observed. Pronounced effect of the heating rate on gelatinization temperature of su₂ mutant were lower than other mutant starches and were affected by the heating rate.     

Structure and Physicochemical Properties of Endosperm Starches of a Waxy Allelic Series and Their Respective Normal Counterparts in the Inbred Oh43 Maize Background

Research over the past three decades has greatly increased our understanding of the biochemical genetics of various waxy (wx) alleles of maize, but our knowledge about the structure and physicochemical properties of endosperm starches obtained from the wx alleles is still incomplete. We further investigated the structure and physicochemical properties of endosperm starches from a wx allelic series and their normal counterparts in the Oh43 inbred background. Starch granules were prepared from mature kernels of wx mutant alleles; wx-C31, wx-R, wx-90, wx-a, wx-B3, wx-m-1, wx-m-8, and wx-S5, and their respective normal counterparts in the inbred Oh43 maize background. Measurements of absorption spectra of starch-iodine complexes and by gel permeation chromatography of Pseudomonasisoamylase-debranched starches showed that all of the starches from the wx allelic series were uniquely waxy type in characteristics, and their normal counterparts were characteristically normal type. Pasting characteristics of starch granules and retrograded starches of the wx allelic series and their respective normal counterparts were investigated by differential scanning calorimetry (DSC). The peak temperature (Tp) and conclusion temperature (Tc) values from starches of the wx allelic series were slightly higher than those of their respective normal counterparts and the ΔHs of starches of the wx allelic series were greater than those of their respective normal counterparts. The onset temperature (To), Tp, and Tc of all retrograded starches were very similar, however, the ΔHs of the retrograded starches of the wx allelic series were greate than those of their respective normal counterpart. Starch granules of the wx allelic series were hydrolyzed more rapidly than those of their respective normal counterparts.     

Effects of lithium salts on ASR gel composition and expansion of mortars

Suppression of alkali-silica reaction (ASR) expansion in mortar and concrete by the addition of lithium salts has been confirmed by some workers. It has been revealed that lithium hydroxide tended to reduce the reaction between sodium or potassium hydroxide and reactive silica, and that the ASR gel incorporating lithium was less expansive. However, it has not been reported how the addition of a lithium salt influenced the composition of the ASR gel. The calcium in ASR gel is considered to play an important role in the expansion of the gel. Thus, it is significant to characterize ASR gel composition in mortars containing lithium salts by BSE-EDS analysis. This study aims to discuss the mechanisms of suppression of ASR expansion in mortar by lithium salts from the viewpoint of ASR gel composition. The average CaO/SiO₂ ratio in ASR gels decreased with increasing amount of added lithium salts. It should be noted that the extent of variations in the CaO/SiO₂ ratio in ASR gels significantly decreased with increasing amount of lithium salts. The addition of relatively small amounts of LiOH and Li₂CO₃ resulted in increased expansion. We also obtained an unexpected result that ASR gels became homogeneous with respect to their CaO contents at high dosage levels. However, the reduction in average CaO/SiO₂ ratios and the homogenization in the CaO content of ASR gels due to the addition of lithium salts may not be related to the expansion of mortars.     

Japanese research on physical chemistry of steelmaking

… Briefly summarizing the work of Japanese investigators on this important aspect of metallurgical technology.     

Effects of absorbed water on the interfacial fracture between two layers of unsaturated polyester and glass

The effects of absorbed water on the interfacial fracture resistance between two layers of unsaturated polyester (UP) and glass of the bilayer specimen were evaluated by measuring a load for producing the fracture by inserting a razor blade into the interface. The specimens were subjected to the cyclic absorption-desorption and the continuous absorption processes of water. The load to initiate the interfacial fracture was markedly lowered by the early absorption process for short period, and then gradually reduced with increasing cycle or period of water absorption, although it slightly recovered after the first great reduction when the specimens were subjected to the soaking process at lower temperatures. The micro-FTIR (ATR) analyses of the detached surface of the UP resin from the glass plate revealed that the water is accumulated in the resin at the interface in the cluster, showing the concentration to increase with increases both in the temperature of environmental water and in the water-soaking period. The IR analyses also demonstrated the hydrolysis reaction to take place on the detached resin surface of specimen exposed to water at high temperature. Thus the accumulated water at the interface may remain and promote the interfacial degradation even under the drying process by various mechanisms like the hydrolysis reaction in hot water environment.     

Fate of perfluorooctanesulfonate and perfluorooctanoate in drinking water treatment processes

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have been recognized as global environmental pollutants. Although PFOS and PFOA have been detected in tap water from Japan and several other countries, very few studies have examined the fate, especially removal, of perfluorinated compounds (PFCs) in drinking water treatment processes. In this study, we analyzed PFOS and PFOA at every stages of drinking water treatment processes in several water purification plants that employ advanced water treatment technologies. PFOS and PFOA concentrations did not vary considerably in raw water, sand filtered water, settled water, and ozonated water. Sand filtration and ozonation did not have an effect on the removal of PFOS and PFOA in drinking water. PFOS and PFOA were removed effectively by activated carbon that had been used for less than one year. However, activated carbon that had been used for a longer period of time (>1 year) was not effective in removing PFOS and PFOA from water. Variations in the removal ratios of PFOS and PFOA by activated carbon were found between summer and winter months.     

利用Microsoft Visual C 设计的基于Windows的永磁电机CAD软件

介绍了利用面向对象的程序设计语言ＭｉｃｒｏｓｏｆｔＶｉｓｕａｌＣ＋＋设计基于Ｗｉｎｄｏｗｓ操作系统的永磁直流电机的计算机辅助设计软件,并针对永磁直流电机编制了组合设计应用软件。通过一台样机钕铁硼高速无刷直流电动机进行了试验验证,获得了满意的结果。