INFLUENCE OF CULTIVAR AND STEEP REGIME ON SOME PROTEIN RELATED PROPERTIES OF SORGHUM MALTS

Cold water extract (CWE), cold water soluble protein (CWS-protein), CWS-protein modification and free alpha amino nitrogen (FAN) were determined for three improved Nigerian sorghum cultivars malted under four different steep conditions. The levels of these variables in the sorghum malts differed significantly when malted under identical steep regimes. This indicates that soluble protein accumulation and modification in these grains are cultivar dependent. Grains exposed to a combination of air rest cycles and final warm steeping gave highest values of cold water solubles, CWS-protein modification and FAN. Amylolytic activity was enhanced over the rate of proteolysis when grains were steeped under regimes incorporating final warm steep. Cultivar SK 5912 with highest soluble protein solubilisation activity showed lowest FAN accumulation under all steep regimes suggesting roles for factors other than proteolysis in FAN accumulation.     

Processing of micro-components made of sintered reaction-bonded silicon nitride (SRBSN). Part 2: Sintering behaviour and micro-mechanical properties

This second part of the report deals with, how the sintering additives Y₂O₃, Al₂O₃, and MgO influence the sintering behaviour of SRBSN. Paraffin-based feedstocks with varying sintering aid compositions and silicon grain size were used for moulding macro- and micro-scale samples. It was observed that compositions with smaller Si grain size (with correspondingly high SiO₂ content) and containing Al₂O₃ as sintering additive exhibit higher shrinkage and lower residual porosity when sintered at 1700–1800 °C after nitridation. The mechanical properties determined for micro-scale samples were obtained by three-point bending tests, with the resulting characteristic strength values σ₀ ranging from 500 MPa up to 1200 MPa. Surprisingly residual porosity did not play the role of a strength limiting factor; rather it was observed that the presence of crystalline secondary phases – mainly Y₂Si₃O₃N₄ – was responsible for reducing the micro-bending strength. As micro-samples exhibit a large surface-to-volume ratio they are in particular affected by decomposition of Si₃N₄ and volatilization of SiO₂ which is considered to be responsible for the occurrence of secondary phases preferred at the sample surface. The powder bed condition was also found to play a prominent role in the development of the secondary phases during liquid phase sintering.     

Adaptive semianalytical inversion of ocean color radiometry in optically complex waters

To address the challenges of the parameterization of ocean color inversion algorithms in optically complex waters, we present an adaptive implementation of the linear matrix inversion method (LMI) [J. Geophys. Res.101, 16631 (1996)], which iterates over a limited number of model parameter sets to account for naturally occurring spatial or temporal variability in inherent optical properties (IOPs) and concentration specific IOPs (SIOPs). LMI was applied to a simulated reflectance dataset for spectral bands representing measured water properties of a macrotidal embayment characterized by a large variability in the shape and amplitude factors controlling the IOP spectra. We compare the inversion results for the single-model parameter implementation to the adaptive parameterization of LMI for the retrieval of bulk IOPs, the IOPs apportioned to the optically active constituents, and the concentrations of the optically active constituents. We found that ocean color inversion with LMI is significantly sensitive to the a priori selection of the empirical parameters g0 and g1 of the equations relating the above-surface remote-sensing reflectance to the IOPs in the water column [J. Geophys. Res.93, 10909 (1988)]. When assuming the values proposed for open-ocean applications for g0 and g1 [J. Geophys. Res.93, 10909 (1988)], the accuracy of the retrieved IOPs, and concentrations was substantially lower than that retrieved with the parameterization developed for coastal waters [Appl. Opt.38, 3831 (1999)] because the optically complex waters analyzed in this study were dominated by particulate and dissolved matter. The adaptive parameterization of LMI yielded consistently more accurate inversion results than the single fixed SIOP model parameterizations of LMI. The adaptive implementation of LMI led to an improvement in the accuracy of apportioned IOPs and concentrations, particularly for the phytoplankton-related quantities. The adaptive parameterization encompassing wider IOP ranges were more accurate for the retrieval of bulk IOPs, apportioned IOPs, and concentration of optically active constituents.     

Relationship between some Sorghum Malt Quality Characteristics and Nature of Alkaline Steep Liquor

Two Nigerian sorghum cultivars, SK5912 and ICSV400 were used to evaluate the relationships between nature of alkaline steep liquor and some malt quality characteristics over a five day germination period. Patterns of development of the malt quality indices examined were significantly influenced by the nature of alkaline steep liquor, cultivar and duration of germination, plus all their possible interactions at p<0.001. Maximum diastatic activity development was attained in ICSV400 and SK5912 when grains were steeped in NaOH and Ca(OH)₂ respectively. Ca(OH)₂ treatment seemed to cause significant enhancement of diastatic enzyme development in SK5912 compared to other treatments presumably due to Ca²⁺ stabilisation of α-amylase. Mean malt cold water extract (CWE) and hot water extract (HWE) were generally similar within both cultivars for the treatments except for ICSV400 where CWE appeared to be remarkably enhanced by NaOH treatment. Data on cold water soluble carbohydrates (CWS-Carbohydrates), CWS — Carbohydrate/CWE and CWS — Carbohydrate/HWE ratios showed that solubilised carbohydrate matter produced during malting constituted significantly higher proportion of total HWE in ICSV400 in contrast to SK5912.     

Experimental and numerical analysis of a multi-stiffened pure aluminium shear panel

The current paper deals with a detailed numerical study carried out on a pure aluminium shear panel and implemented through a FEM numerical model calibrated on the results obtained by an experimental test. The comparison between experimental and numerical data, in terms of dissipative capacity, maximum hardening ratio, secant shear stiffness and equivalent viscous damping factor, is carried out in order to show that the proposed model is reliable enough to well interpret the actual behaviour of the specimen, which exhibits many buckling phenomena and large plastic deformations. The proposed model is therefore profitably used to detect the exact displacement levels corresponding to the activation of the main buckling phenomena, as well as the stresses acting on the boundary bolted connections, which may result the weak point of the system. Moreover, the main outcomes of a parametrical study, which are implemented on the basis of the calibrated numerical model, are critically discussed and properly analysed, in order to define the erosion factor of the shear strength due to buckling.     

EFFECTS OF AIR REST PERIOD ON THE MOBILISATION OF SORGHUM RESERVE PROTEINS

The influence of air rest treatment period on the mobilisation of storage proteins of two improved Nigerian sorghum cultivars ICSV 400 and KSV 8 was evaluated. Grains were steeped in distilled water for a total period of 48 h at 30°C with a 6 h final warm steep at 40°C under four different cycles incorporating 1, 2, 3 or 4 h air rest period respectively. Cold water soluble protein, cold water soluble protein modification index, total cold water solubles, total free alpha amino acid nitrogen, carboxy-peptidase and proteinase activities were determined after 6 days malting. All these protein modification indices were highly significantly affected by length of air rest and cultivar, plus their pair-wise interactions. The levels of all these variables were also higher in sorghum cultivar ICSV 400 compared to KSV 8 except for proteinase activity. Significant differences in grain storage protein complexity and structure coupled with probable differences in key proteinase iso-forms are advanced as possible explanation for the higher proteinase activity recorded in KSV 8 malts.     

建筑文脉还起作用吗？请听“间舍”的回答

文章分析了超城建筑设计的“间舍”——一个直接融入建筑文脉并面向不可预知未来的新生代建筑。“间舍”坐落于山东烟台的某个景观残缺之地，虽是一个小型项目，却展示了无数可伸展的层次，其目的是给出一些有关中国现代建筑的新答案和想法。     

Purification and some properties of a novel raw starch‐digesting amylase from Aspergillus carbonarius

A medium was developed to obtain the maximum yield of raw starch‐digesting amylase from Aspergillus carbonarius (Bainier) Thom IMI 366159 in submerged culture with raw starch as the sole carbon source. The amylase was purified to apparent homogeneity by sucrose concentration and ion exchange chromatography on S‐ and Q‐Sepharose (fast flow) columns. SDS‐PAGE revealed two migrating protein bands corresponding to relative molecular masses of 31.6 and 32 KDa. The enzyme was optimally active at pH 6.0–7.0 and 40 °C, was uninfluenced across a relatively broad pH range of 3.0–9.0 and retained over 85% activity between 30 and 80 °C after 20 min incubation. The enzyme was strongly activated by Co²⁺ and only slightly by Fe²⁺, while Ca²⁺, Hg²⁺, EDTA and N‐bromosuccinamide elicited significant repression of the enzyme activity. The enzyme hydrolysed amylopectin (K_m 0.194 mg ml ⁻¹), glycogen (K_m 0.215 mg ml ⁻¹), pullulan (K_m 0.238 mg ml ⁻¹), amylose (K_m 0.256 mg ml ⁻¹) and raw potato starch (K_m 0.260 mg ml ⁻¹), forming predominantly maltose and relatively smaller amounts of glucose. © 2000 Society of Chemical Industry     

Space-filling experimental designs for constrained design spaces

Conventional space-filling experimental design provides uniform coverage of a hypercube design space. When constraints are imposed, the results may contain many infeasible points. Simply omitting these points leads to fewer feasible points than desired and a design of experiments that is not optimally distributed. In this research, an adaptive method is developed to create space-filling points in arbitrarily constrained spaces. First, a design space reconstruction method is developed to reduce the invalid exploration space and enhance the efficiency of experimental designs. Then, a synthetic criterion of uniformity and feasibility is proposed and optimized by the enhanced stochastic evolutionary method to obtain the initial sampling combination. Finally, an adaptive adjustment strategy of design levels is constructed to obtain the required number of feasible points. Various test cases with convex and non-convex, connected and non-connected design spaces are implemented to verify the efficacy of the proposed method.