Variation in Malting Quality and Heat Resistance in the Malting Barley Variety “Alexis”

In earlier studies concerning vigour, where subsamples are heat‐treated before germination there was found heat‐sensitive as well as heat‐resistant barley samples. The vigour model developed by Ellis and Roberts and further developed at Carlsberg, could only describe the heat‐sensitive barleys. Seventeen samples of the “Alexis” variety grown widely in Europe were collected from the EBC trials in 1994 in order to see if heat resistance in barley was influenced by different growing conditions. We found both heat‐sensitive samples following the vigour model as well as pronounced heat‐resistant samples, but these were not divided according to growing conditions. The germination curves dependent on heat treatment and germination time were evaluated by Principal Component Analysis (PCA). Heat‐resistant barley samples could be differentiated from heat‐sensitive samples already after ½ h of heat treatment at 68°C (12% moisture) and after 3 days of germination. The barley samples were analysed with regard to malting quality. The PCA evaluation of the data divided the samples according to growing location, mainly due to differences in protein and β‐glucan. However, the malting analyses could not describe the differences in heat resistance and sensitivity of the barleys. The biochemical background of the heat resistance found is discussed on the basis of literature. Our findings should give an experimental basis for exploiting a biochemical principle for heat resistance, which is formed during grain filling and consumed during storage and germination.     

An efficient return algorithm for non-associated plasticity with linear yield criteria in principal stress space

An efficient return algorithm for stress update in numerical plasticity computations is presented. The yield criterion must be linear in principal stress space and can be composed of any number of yield planes. Each of these yield planes may have an associated or non-associated flow rule. The stress return and the formation of the constitutive matrix is carried out in principal stress space. Here the manipulations simplify and rely on geometrical arguments. The singularities arising at the intersection of yield planes are dealt with in a straightforward way also based on geometrical considerations. The method is exemplified on non-associated Mohr–Coulomb plasticity throughout the paper.     

An overall model for maintenance optimization

This paper presents an approach for identifying the optimal maintenance schedule for the components of a production system. Safety, health and environment objectives, maintenance costs and costs of lost production are all taken into consideration, and maintenance is thus optimized with respect to multiple objectives. Such a global approach to maintenance optimization requires expertise from various fields, e.g., decision theory, risk analysis and reliability and maintenance modelling. Further, a close co-operation between management, maintenance personnel and analysts is required to achieve a successful result. In the past this has been a major obstacle to the extensive use of proper maintenance optimization methods in practice, and techniques to promote the communication between the involved parties of the optimization process is an essential element in the suggested approach. A simple step by step presentation of the required modelling is provided. Contrary to most current methods of RCM (Reliability Centered Maintenance), the approach is based on an analytic model, and therefore gives a sound framework for carrying out a proper maintenance optimization. The approach is also flexible as it can be carried out at various levels of detail, e.g., adopted to available resources and to the managements willingness to give detailed priorities with respect to objectives on safety vs production loss.     

Design and Characterization of the CLIMPAQ,Chamber for Laboratory Investigations of Materials,Pollution and Air Quality*

A test chamber has been developed in order to provide a small and simple emission testing facility capable of testing construction products in a climate where the important climatic parameters such as temperature, ventilation rate and air velocity can be varied independently around typical indoor values. The test chamber CLIMPAQ is made of panes of window glass. Other main surface materials are stainless steel and eloxated aluminium. The chamber has a volume of 50.9 litres and is designed to meet the requirements for quantifying air pollution. In this investigation human subjects acted as air pollution judges, and chemical characterization of the air pollution was carried out. Carpet, linoleum, wall paint and seal- ant were tested simultaneously in the CLIMPAQ and in four other chambers ranging from a full-scale chamber of 28 m³ to a field and laboratory emission cell of 3.5· 10^?5m³. Product ranking is the same in all chambers for the sensory measurements. Emission rates based on sensory measurements differ for all products less than 100 % except for tests in a 3-litre chamber where emission rates were higher. Chemical measurements differ up to approximately 10 times for the same product in different chambers. Deviations appear to be the result of different environmental parameters in the various chambers. Low air concentrations or high specific ventilation rates seem to increase emissions, while differences in air velocities and sink properties may also be the cause of differences in emission rates.     

Evidence for Remote Effects of Dreissenid Mussels on the Amphipod Diporeia: Analysis of Lake Ontario Benthic Surveys, 1972–2003

The status of invasive dreissenid mussels (Dreissena polymorpha and D. bugensis) and native amphipods (Diporeia spp.) in Lake Ontario was assessed in 2003 and compared with historical data. D. polymorpha (zebra mussels) were rarely observed in 2003, having been displaced by D. bugensis (quagga mussels). D. bugensis expanded its depth range from 38 m depth in 1995 to 174 m in 2003 and this dreissenid reached densities averaging 8,000/m² at all sites < 90 m. During the same time period, Diporeia populations almost completely disappeared from 0–90 m depth, continuing a declining trend from 1994–1997 reported in previous studies. The average density of Diporeia in the 30–90 m depth interval decreased from 1,380/m² to 63/m² between 1997 and 2003. Prior to 2003, areas deeper than 90 m represented a refuge for Diporeia, but even these deep populations decreased, with densities declining from 2,181/m2 in 1999 to 545/m2 in 2003. Two common hypotheses for the decline of Diporeia in the Great Lakes are food limitation and a toxin/pathogen associated with dreissenid pseudofeces. The Diporeia decline in deep waters preceded the expansion of D. bugensis to these depths, and suggests that shallow dreissenid populations remotely influence profundal habitats. This pattern of decline is consistent with mechanisms that act from some distance including nearshore dreissenid grazing and downslope transport of pseudofeces.     

Influence of the temperature profile in the interface on the bond strength of polyamide–polyurethane two‐component tensile bars

Two‐component tensile bars with polyamide 6 (PA) and thermoplastic polyurethane (TPU) unmodified and modified with 4,4′‐diphenylmethane diisocyanate (MDI) have been investigated. It is known that the bond strength of PA/TPU tensile bars can increase by about 50% if MDI‐modified polyurethane is applied. The subject of these studies is the analysis of the influence of the mass temperatures on the bond strength. The mass temperatures of the first and second injection process and the delay time between the first and second injection processes determine the temperature gradient in the interface at the moment of the second injection. There is an increase in the bond strength when there is an increasing temperature gradient; therefore, the mass temperature of the first component at the delay time has to be lower than the mass temperature of the second component. The temperature gradient can be used as a measure of the thermal annealing of the first component near the interface during the heat transfer from the second component. It can be concluded that effective thermal annealing causes an increase in the bond strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4297–4305, 2006     

External-Memory Algorithms for Processing Line Segments in Geographic Information Systems

In the design of algorithms for large-scale applications it is essential to consider the problem of minimizing I/O communication. Geographical information systems (GIS) are good examples of such large-scale applications as they frequently handle huge amounts of spatial data. In this paper we develop efficient external-memory algorithms for a number of important problems involving line segments in the plane, including trapezoid decomposition, batched planar point location, triangulation, red--blue line segment intersection reporting, and general line segment intersection reporting. In GIS systems the first three problems are useful for rendering and modeling, and the latter two are frequently used for overlaying maps and extracting information from them.     

Integration of multiple national markets for electricity: The case of Norway and Sweden

During the second part of the 1990s the Nordic (Denmark, Finland, Norway and Sweden) countries have created a unique multinational market for electricity. This paper aims to analyse the degree of integration of the different national markets that constitute the Nordic electricity market. In particular the Norwegian and Swedish wholesale and retail electricity markets are analysed. The results suggest that the wholesale markets are well integrated. Thus prices differ significantly only during periods with unusually high or low supply of hydropower. However, the retail markets are not integrated to the same degree. Thus retail prices and trade margins differ significantly. Differences in the national electricity market legislation seem to be a key factor behind these differences.     

FMS50柔性加工系统

本文对FMS50系统结构进行了介绍，着重阐述了该系统的多种物流模式．并分析了其通信控制系统的构成。     

Good ergonomics and team diversity reduce absenteeism and errors in car manufacturing

Prior research suggests that ergonomics work design and mixed teams (in age and gender) may compensate declines in certain abilities of ageing employees. This study investigates simultaneous effects of both team level factors on absenteeism and performance (error rates) over one year in a sample of 56 car assembly teams (N = 623). Results show that age was related to prolonged absenteeism and more mistakes in work planning, but not to overall performance. In comparison, high-physical workload was strongly associated with longer absenteeism and increased error rates. Furthermore, controlling for physical workload, age diversity was related to shorter absenteeism, and the presence of females in the team was associated with shorter absenteeism and better performance. In summary, this study suggests that both ergonomics work design and mixed team composition may compensate age-related productivity risks in manufacturing by maintaining the work ability of older employees and improving job quality.