HOMOGENEITY OF THE FRIABLE FLOUR OF MALTING BARLEY

A detailed comparison was made of the properties of the friable flours and non-friable residues of two samples of malted barley of different nitrogen contents. The friable flours were sieved and fractionated to give a range of particle sizes, and the intact malt, whole friable flour, non-friable residues and fractionated friable flours were subjected to a range of analyses. Endosperm fractionation studies showed that the pattern of enzymic degradation of proteins in the modified friable flour of low nitrogen malt was more uniform than the corresponding pattern of protein breakdown in the friable flour of high nitrogen malt. Examination of the non friable residues showed that cell wall breakdown in the high nitrogen malt was less extensive than the low nitrogen malt. It is proposed that the high protein levels in the endosperm caused starch/protein compacting which limited endosperm hydration and enzymic modification during malting. The friability scores of high nitrogen malts may given an over estimate of endosperm modification.     

INCUBATION OF BARLEY KERNEL SECTIONS WITH PURIFIED CELL WALL DEGRADING ENZYMES

The effects of purified Trichoderma reesei endo-xylanase, XYN II and endoglucanases, EG I and EG II on the cell walls of embedded barley cross sections were studied. The cell walls were stained with Calcofluor which is specific for (1–3)(1–4)-β-D-glucans (mixed-linked β-glucans) in histochemical applications. Whereas endosperm cell walls remained highly fluorescent after incubation with buffer, the aleurone cell walls were only weakly fluorescent. Both EG I and EG II were effective in degrading the outer endosperm cell walls, but had little or no effect on the inner endosperm and aleurone cell walls. Corresponding sections incubated with XYN II showed highly intensive fluorescence of aleurone cell walls suggesting that the surface of alaurone cell walls contains a high level of xylan which is removed by xylanase treatment exposing a layer rich in mixed linked β-glucans. This indicates that arabinoxylans and β-glucans in the aleurone cell walls of barley exist as separate, macroscopic layers. Xylanase did not have any Influence on the microstructure of endosperm cell walls which are rich in mixed linked β-glucans. However, incubation with EG II after xylanase treatment caused the aleurone cell walls to become very thin.     

MCT technology challenges for mass production

Second generation infrared (IR) detectors are now mature at the production level. These detectors are mostly based on HgCdTe (MCT) materials technology. The main second generation detectors at the mass production level are the 288 4 long wave length for most of the European forward-looking infrared (FLIR) and the 480 6 long wave length for the U.S. Army SADA applications. As far as the 288 4 is concerned, SOFRADIR has delivered more than 3000 units already and the market is estimated to be 15,000 units at least! The market is also very large for SADA II units and SOFRADIR has produced them since the end of 1999. Thus, SOFRADIR produces large quantities of mercury cadmium telluride (MCT) detectors and has a unique experience for MCT detectors in mass production. MCT materials technology challenges for mass production concern the main following issues: Quality and reproducibility, MCT wafer size increase, array yield level increase, and the collective manufacturing approach. These issues are discussed in detail in this paper as well as future trends.     

VACUUM PACKAGING OF NEW ZEALAND HOPS

Three cultivars of New Zealand hops were packaged in two ways, vacuum and non-vacuum, and stored at two temperatures, 0°C and ambient. Over the 38 week test period the degradation of Lead Conductance Value was linear for all treatments with no difference between cultivars and no evidence of a ‘safe’ or ‘delay’ period. The degradation coefficient [Lead Conductance Value (%)/week] was highest for non-vacuum packed, ambient (?0·151), followed by non-vacuum packed refrigerated (?0·077), vacuum packed ambient (?0·039) and vacuum packed refrigerated (?0·012).     

EVALUATION OF MALTING QUALITY IN A BARLEY BREEDING PROGRAMME USE OF α-AMYLASE AND β-GLUCAN LEVLES IN MALT AS PRESELECTION TOOLS

Analysis according to the EBC protocol, immunological determination of a α-amylase and estimation of malt β-glucan using the Calcofluor-FIA method, were used to screen 327 barley breeding lines for malting quality. The results obtained with the α-amylase and β-glucan methods are highly correlated to the important malt quality paramters: extract yield and β-glucan content in the wort. It is recommended that either of the two methods, which are simple to perform are used as prescreening tools in breeding programmes for malting barley.     

STARCH DEGRADATION IN ENDOSPERMS OF DEVELOPING BARLEY KERNELS*

Shortly after anthesis, empty endosperm cells adjacent to the embryo were crushed between the developing embryo and endosperm tissues to form the crushed cell layer. Starch granules in cells adjacent to this layer were hydrolysed and the empty cells were added to the crushed layer. In this way, the crushed layer increased in thickness throughout kernel development. α-Amylase 2 was detected in the crushed cell layer region of barley endosperms during the period that starch granule hydrolysis was occurring.     

THE CONTRIBUTION OF DEXTRINS OF BEER SENSORY PROPERTIES PART II. AFTERTASTE

We investigated the possibility that dextrins could contribute to the aftertaste of beer by being broken down to sweet sugars by salivary α-amylase after beer Ingestion. The volume, pH and temperature of beer and saliva present in the oral cavity after swallowing were measured on several subjects and found adequate for the hydrolysis of beer dextrins by salivary amylase. The in vitro hydrolysis of a 6% dextrin solution and of commercial beers by pancreatic α-amylase yielded significant amounts of glucose and maltose in addition to maltotriose. Similarly, the hydrolysis of commercial beers by human saliva produced between 2.7 and 7.4 g/litre of sweet-tasting maltose and glucose, depending on the duration of the hydrolysis (30 sec to 2 min) and the amount of saliva added to 2.5 ml of beer (0.5 or 2 ml). This much sugar, because it is produced over a period of time, may not cause a detectable sweet taste but it might partially mask the bitter aftertaste of beer.     

Non‐Lithographic Fabrication of All‐2D α‐MoTe2 Dual Gate Transistors

As one of the emerging new transition‐metal dichalcogenides materials, molybdenum ditelluride (α‐MoTe₂) is attracting much attention due to its optical and electrical properties. This study fabricates all‐2D MoTe₂‐based field effect transistors (FETs) on glass, using thin hexagonal boron nitride and thin graphene in consideration of good dielectric/channel interface and source/drain contacts, respectively. Distinguished from previous works, in this study, all 2D FETs with α‐MoTe₂ nanoflakes are dual‐gated for driving higher current. Moreover, for the present 2D dual gate FET fabrications on glass, all thermal annealing and lithography processes are intentionally exempted for fully non‐lithographic method using only van der Waal's forces. The dual‐gate MoTe₂ FET displays quite a high hole and electron mobility over ≈20 cm² V^?1 s^?1 along with ON/OFF ratio of ≈10⁵ in maximum as an ambipolar FET and also demonstrates high drain current of a few tens‐to‐hundred μA at a low operation voltage. It appears promising enough to drive organic light emitting diode pixels and NOR logic functions on glass.     

H optimal approximation for causal spline interpolation

In this paper, we give a causal solution to the problem of spline interpolation using H^∞ optimal approximation. Generally speaking, spline interpolation requires filtering the whole sampled data, the past and the future, to reconstruct the inter-sample values. This leads to non-causality of the filter, and this becomes a critical issue for real-time applications.Our objective here is to derive a causal system which approximates spline interpolation by H^∞ optimization for the filter. The advantage of H^∞ optimization is that it can address uncertainty in the input signals to be interpolated in design, and hence the optimized system has robustness property against signal uncertainty.We give a closed-form solution to the H^∞ optimization in the case of the cubic splines. For higher-order splines, the optimal filter can be effectively solved by a numerical computation. We also show that the optimal FIR (finite impulse response) filter can be designed by an LMI (linear matrix inequality), which can also be effectively solved numerically. A design example is presented to illustrate the result.     

非晶碲镉汞薄膜的暗电导与光电导

This paper reports the dark conductivity and photoconductivity of amorphous Hg_(0.78)Cd_(0.22)Te thin films deposited on an Al_2O_3 substrate by RF magnetron sputtering.It is determined that dark conduction activation energy is 0.417 eV for the as-grown sample.Thermal quenching is absent for the as-grown sample during the testing temperature zone,but the reverse is true for the polycrystalline sample.Photosensitivity shows the maximum at 240 K for amorphous thin films,while it is higher for the as-grown ...