Crystalline Parts of Three Different Conformations Detected in Native and Enzymatically Degraded Starches

We examined cereals and legume starches with different amylose contents, using X-ray wide-angle scattering. The parts of polymorphs in the crystalline regions and the crystallinity of the starches were determined. The high-amylose starches hold 74.6%-84.6% B-type and 15.4%-22.6% VH-type. Crystallinity of high-amylose starches is xc = 0.154–0.17. According to phase analysis of the scattering curve of wheat starch 6.8% B-type and 93.2% A-type are contained. Thus, in the crystalline phase wheat starch is more heterogeneous than maize starch. The residuary substance of heterogeneous hydrolysis of wheat starch at T1 =58°C is an insoluble sediment, which does contain already 17.1 % VH-Amylose. This is the proof of the amylose-lipid complex in the sediment. If the temperature of hydrolysis raised to 70°C, the VH,-amylose proportion increased to 80.5%. Since the crystalline VH- structures are detectable during heterogeneous hydrolysis as from T1 = 58°C, they seem to have contained already in native starch.     

Hydrothermische Behandlung von Stärke in Gegenwart von α-Amylase Teil 2: Einfluß einer hydrothermischenzymatischen Modifizierung auf die Quellungstemperatur von Weizenstärken

Hydrothermal Treatment of Starch in the Presence of α-Amylase. Part 2: Effect of a Hydrothermal Enzymatic Modification on the Swelling Temperature of Wheat Starches. The hydrothermal treatment of wheat starch in the presence of bacterial-α-amylase is directed to the production of modified residual starches with a maximal shift of swelling temperature T_max (measured by DSC) at high yields. The annealing of granular starch at temperatures below the swelling temperature (50°C) in presence of α-amylase gives no difference regarding the shift of T_max. Because of the hydrolysis of swollen material it is possible to use higher reaction temperatures and the process becomes more effective. The formed maltose syrup retards the shift of T_max and protects the granules. Within 24h wheat starch can be modified with a yield of 70% and a shift of T_max of 8K.     

Über Gesetzmäßigkeiten in der π-Elektronenstruktur von heteroanalogen Polyvinylidenverbindungen

On Regularities of the π-Electronic Structure of Heteroanalogous Polyvinylidene Compounds Starting with simple forms of the equations for the eigenvalues and eigencoefficients of the π-system of heteroanalogous polyvinylidene compounds 3 several regularities in the π-electronic structure of these systems are derived and compared with known experimental facts. In this line several predictions are given for the properties of compounds unknown up to now.     

Acylierung von Heterocyclen mit Kohlensäurederivaten. II. Endo- und exo-Carbamoylierung von 2-Amino-benzimidazol-Derivaten mit Isocyanaten. Mechanismus der Acylgruppenwanderung

Acylation of Heterocycles with Carbonic Acid Derivatives. II. Endo and Exo Carbamoylation of 2-Amino-benzimidazole Derivatives with Isocyanates. Mechanism of the Acyl Group Migration 2-Amino-benzimidazoles react with isocyanates with good yields to give 2-amino-1-carbamoyl-aminobenzimidazoles 1 at −30°C and the corresponding 2-carbamoyl isomeres 2 at room temperature, respectively. The isomerization mechanism was studied by crossover experiments and kinetic measurements and has been found to consist of inter- and monomolecular acyl transfer.     

Fuelwood: The “other” renewable energy source for Africa?

In recent years, increasing concerns over rising oil prices, supply shortfalls and the environmental impacts of fossil fuel use have fed growing interest in renewable energy sources for Sub-Saharan Africa. Although traditional biofuels already enjoy widespread popularity, their use has often been actively discouraged due to the lingering influence of “fuelwood crisis” era narratives. In particular, urban fuelwood consumption is frequently portrayed as a cause of environmental degradation leading to energy insecurity among low-income households, especially where the resource is commercialized. Such views have had significant influence among policy makers, often resulting in repressive forestry legislation. In contrast, however, a number of researchers have demonstrated that wood energy dependence is often not a significant cause of deforestation and can provide important livelihood opportunities. This article reassesses urban fuelwood sourcing and its impacts using a recent case study conducted by the authors in Maun, Botswana and results previously reported in the literature. Findings indicate that although harvesting is unregulated, its impacts are significantly mitigated by collectors' strong preferences for source sites with abundant dead wood, low competition and recognized access rights. As well, fuelwood vending is found to provide critical support to rural incomes and a key source of low-cost urban energy. As such, the benefits of fuelwood use and avoidance of negative effects will most effectively be achieved by decentralised management approaches that build on local institutions and understandings of the resource.     

分布式设备远程监控系统研究

针对现有设备远程监控系统不能真正有效地支持分布式网络化生产和管理模式,提出一种基于中间件技术的分布式工业设备远程维护系统,该系统不依赖于具体的硬件和软件平台,设备能方便地加入或退出系统。阐述了系统总体结构和系统安全性设计,重点分析了实现分布式结构的关键技术—查询服务器的4个机制及其实现技术方案,并讨论了系统的总体通讯方案,为分布式设备远程服务系统的实现提供了很好的参考价值。该系统有效地提升了企业关键设备的维护效能,为设备远程监控系统的应用推广奠定了基础。     

Computer simulation of the initial rafting process of a nickel-base single-crystal superalloy

Rafting of the γ/γ′ morphology of nickel-base superalloys is a well-known phenomenon during high-temperature deformation. The initial stages of this type of directional coarsening were modeled two-dimensionally by the method of finite elements (FEs) using an energy-perturbation approach. In addition to the elastic energy density, the effect of the local difference of the hydrostatic stresses in γ and γ′ in combination with the different lattice parameters of the two phases was considered in the calculations as a further driving force. From the results of modeling, the deformation-induced internal stresses and strains were determined and used to evaluate the direction-dependent lattice parameters and lattice misfits of the two phases. The results agree well with experimentally determined values.     

Neue Konstruktionsprinzipien bei Tunnelinnenschalen

New Design Philosophy of Inner Tunnel Linings Examinations are presented aiming at the optimisation of reinforcement and thickness of an inner tunnel lining in order to improve the behaviour at serviceability (SLS) and ultimate limit state (ULS). It is expected that especially an acceleration of the construction progress leads to advantages in competition compared with conventionally reinforced linings. A reduced thickness of a lining out of steel fibre concrete (SFB) or a combination of reinforced concrete and steel fibres (SFvSTB) came out best when being experimentally and theoretically examined. Particularly with regard to the cracking formation at SLS, that rules the design of watertight linings, the slender lining is advantageous compared to a conventionally reinforced one (STB).     

STM investigation of the growth structure of Cu-phthalocyanine films with submolecular resolution

In this study Cu-phthalocyanine (CuPc) films have been investigated by scanning tunneling microscopy to get quantitative insight into the morphology of the films from the micrometer range down to nanometer resolution to see the arrangement of the molecules. The molecules on the surface have been found to be arranged in a slipped stacking order rather than in the expected zig-zag orientation normally found for CuPc crystals. The cystal structure could be identified to be an α-polymorph. The STM image of the individual molecules on the surface is in good agreement with calculations of the charge density of the LUMO for an isolated molecule. A model for the growth of the crystals was derived from this study.