Temporal changes in the periphytic algal communities in a drowned tropical forest reservoir in Malaysia: Lake Kenyir

Periphytic algal assemblages, comprising bacillariophytes, cyanophytes and chlorophytes of standing dead trees in Lake Kenyir, a tropical drowned forest reservoir, were studied during 1995. A total of 317 algal taxa were identified in this study. The monthly floral mean species richness and cell count data demonstrated significant temporal differences between the months, in one-way anova (P < 0.05). Both redundancy analysis and cluster analysis on monthly blue-green abundance and diatom assemblages exhibited conspicuous groupings among the months, with underpinning seasonal differences. The responses were not similar, however, between the upstream and downstream ends of the lake. The grouping or clustering of months can be generalized as: (i) November, December and January as the monsoonal months; (ii) February, March, April and May as the transitional months; and (iii) June to October as the dry months. Based on stepwise multiple regression with forward selection, alkalinity and dissolved oxygen concentration were significant environmental predictors at the downstream dam sampling site, and reactive silica, electrical conductivity, Secchi depth transparency and sunshine hours were significant predicators at the upstream riverine sampling site, based on Monte Carlo tests. Being a ploymictic, mesotrophic lake, the limnology and temporal changes for Lake Kenyir appears to be complex and driven by monsoons, as evidenced from the temporal changes in its periphytic algae communities, particularly the diatom assemblages. The downstream sampling site (site 1) at the dam, in the main basin and deeper zone of the lake, the seasonal amplitude was likely complex because of thermocline formation and stratification processes. In contrast, the upstream sampling site in the Petang River (site 2) exhibited a clearer distinction between the dry and monsoon months, based on its cyanophyte and diatom floral assemblages. These study results are pertinent for lake management, especially for developing biomonitoring programmes or lake productivity studies, as well as for climate change studies, within the context of tropical lake ecology.     

The local bearing capacity perpendicular to grain of structural timber elements

The accuracy and reliability of empirical models for the local bearing capacity perpendicular to grain of timber beams is questionable as it is not based on any fundamental principal. This study shows that a physically based stress dispersion model can successfully be applied for a wide range of practical design situations. The credibility of this model is based on experiments, FEM and optical techniques used to assess and quantify the strength affecting parameters. This model is a potential candidate to be incorporated in future structural timber design standards.     

Prophid: A Platform-Based Design Method

The continuing trendtowards higher integration densities of integrated circuits makesthe development of systems-on-a-chip possible. For well-definedapplication domains ``silicon platforms' must be defined whichallow efficient, yet programmable implementations. These platformsare heterogeneous reconfigurable multiprocessor architecturessupporting a variety of communication and computation models.As a consequence designers are facing a large architecture spacewith new possibilities for new architectures. To exploit theseopportunities a better understanding of system level architecturesis necessary. A first step in this direction is to learn fromdesign exercises. Eventually this may lead towards a system leveldesign method. In this paper a multiprocessor architecture templateis presented that serves as a platform for high-throughput applications.Central to this architecture is a reconfigurable high-performanceprocessor network that uses communication concepts based on theTST-networks known from the literature. We discuss the characteristicsof the architecture template in detail. Furthermore, we willdiscuss the specification, modelling, and mapping of applicationsfor this architecture. Finally, we analyse cost and performancefigures using real implementation results.     

1.18 A versatile cryopump for industrial vacuum systems

The advantages of cryopumping, e.g. high pumping speed, flexibility, cleanliness and wide pressure range of operation, have long been recognised. Nevertheless, industrial application of this method has been rejected so far. This paper describes the vacuum performance of a cryopump equipped with a recently introduced cryogenerator. The machine offers a cold production of approximately 50 W at 80 K and 10 W at 20 K simultaneously, thus eliminating the need for a liquid helium and (or) nitrogen supply. Data presented show that industrial applications of cryopumping at 20 K impose special requirements on the design of the cryopanels and the cold capacity of the cryogenerator. It is shown that a 10 W cold capacity will offer long term operation of the pump, particularly in industrial thin film coaters, if (a) hydrogen gas is distributed uniformly over an adsorbent glued on a 20 K panel, (b) the grain size of the adsorbent is about one millimetre, and (c) contamination of the adsorbent by gases more easily condensable than hydrogen is avoided.     

Requirements for moment connections in statically indeterminate timber structures

In statically indeterminate structures, connections play a vital role in the moment distribution. Demonstrated here is a method to evaluate the conditions, taking full advantage of the benefits offered by the indeterminate nature of the structures, and using the well-established, graphical beam-line method. This method shows how important the immediate load take-up is, the stiffness, the moment capacity of the connection and how it all affects the structural behaviour. The examples considered here use both the traditional non-reinforced dowel-type fastener connections and also timber connections reinforced with steel plates. They show that the minimum rotation requirements to achieve an effective structure are satisfied easily in contrast to requirements on stiffness. In this respect, timber connections with local reinforcement glued at the interface of the connection area offer more prospects.     

The clinical effect of a new infant formula in term infants with constipation: a double-blind,randomized cross-over trial

Background  

Nutrilon Omneo (new formula; NF) contains high concentration of sn-2 palmitic acid, a mixture of prebiotic oligosaccharides and partially hydrolyzed whey protein. It is hypothesized that NF positively affects stool characteristics in constipated infants.