Development of single nucleotide polymorphism markers from ESTs for discrimination between domestic and imported manila clams,Ruditapes philippinarum

Large amounts of the manila clam, Ruditapes philippinarum, have been imported from Dalian (China) recently to meet the increasing demand in Korea. To ensure the quality and safety of the domestic marine product, it is necessary to be able to distinguish between domestic manila clams and clams that are imported from Dalian, China. We developed expressed sequence tags (ESTs)-derived single nucleotide polymorphism markers using 454 pyrosequencing. A total of 780,000 ESTs were assembled, and 49,540 putative SNPs were identified from 46,405 contigs. Twenty-one polymorphic SNPs from 11 primers were finally selected as diagnostic markers. Genotype analysis showed that 21 SNP markers had the opposite alleles (transitions or transversions) between domestic and imported samples, which were useful for distinguishing clam origins. The GENECLASS 2.0 program was used to estimate the ability of the markers in the discrimination between domestic and imported populations. The 21 SNP markers had 98.96% ability to discriminate domestic manila clams and 100% ability to identify those imported. These markers could be useful for discriminating between domestic and imported manila clams and can contribute to the prevention of falsified labeling of this species.     

Flocculation and mechanism of self-flocculating lipid producer microalga Scenedesmus quadricauda for biomass harvesting

In this study, the extracellular polymeric substance of Scenedesmus quadricauda called EPS-S.q and its bioflocculatoin mechanism were investigated. Results showed EPS-S.q was successfully used as bioflocculating agent for S. quadricauda biomass harvesting and flocculation efficiency of up to 86.7% to S. quadricauda cells could be achieved in presence of Zn²⁺. EPS-S.q was the flocculating agent for self-flocculating microalga S. quadricauda and bioflocculation mechanism was polymer bridging. The sugar and protein mass fraction of dry EPS-S.q was sugar 56.7% and protein 41%. The infrared spectrum further indicated the presence of hydroxyl, carboxyl and amino groups. Moreover, pH decrease induced the flocculation of S. quadricauda and 78.4% of flocculation efficiency was the highest at pH 3. In addition, chemical flocculant FeCl₃ was efficiently used for S. quadricauda harvesting and up to 96.8% of flocculation efficiency could be achieved for S. quadricauda culture with biomass concentration 0.21–0.39 g L⁻¹ at pH 7.     

Hybrid quality adaptation mechanism for layered multicast over the internet

The use of multicast for distribution of real-time video over the Internet has received greater attention over the past few years. Unfortunately, a major challenge to its wide usage is the heterogeneity of networks and receivers. In this paper we proposed a mechanism called Hybrid Quality Adaptation (HQA) for multicasting layered MPEG-2 video. The receiver will subscribe to the number of layers based on their network and end-system resources. On the other hand, the video server adjusts the transmission characteristics of each layer to try and accommodate the requirements of the majority of the receivers. A prototype layered MPEG-2 multicast system, using HQA, has been successfully developed.     

Phosphorus in rivers — ecology and management

This paper examines the nature of the risk to riverine ecosystems from artificially enhanced loads of phosphorus, considers the key sources of phosphorus enrichment and ways of controlling them, and provides a framework for developing control strategies. The aquatic plant community is the foundation for a healthy and diverse riverine ecosystem, providing food, shelter and breeding habitats for a wide range of animal species. Phosphorus enrichment in rivers can degrade the plant community by altering the competitive balance between different aquatic plant species, including both higher plants and algae. This has consequences for the whole ecosystem. To promote healthy riverine plant communities and the wide range of animal species dependent on them, phosphorus concentrations need to be reduced to as near to background levels as possible. The risk of adverse effects declines as phosphorus concentrations approach background levels, such that any incremental reduction should be seen as a positive step towards trophic restoration. Pragmatic management targets vary between 0.02 and 0.1 mg l⁻¹ soluble reactive phosphorus, depending on river type, with an interim target of 0.2 mg l⁻¹ for heavily enriched rivers. Continuous point sources of phosphorus, dominated by sewage treatment works, have a highly important influence on levels of bioavailable phosphorus in the water column through the growing season. It is important to tackle point sources comprehensively so that reductions in phosphorus concentrations are maximised during this critical time of year. Diffuse sources of phosphorus, particularly from agriculture, are a major contributor to phosphorus levels in riverine sediments, where it can be utilised by benthic algae and rooted plants. This phosphorus can also be released into the water column by a variety of processes. As point sources are brought under control, the relative contribution from diffuse sources becomes increasingly important. An integrated programme of control, involving proactive action on both point and diffuse sources, will be required in most circumstances to bring phosphorus levels in the water column and sediment down to near background levels.     

General method for predicting the sand erosion rate of GFRP

Sand erosion behavior and wear mechanism of various types of glass fibre reinforced plastics (GFRP) were investigated. Erosion behavior of fibre reinforced plastics (FRP) changed from ductile manner to brittle one with increase of glass fibre content, and erosion rate was maximum at vertical impact for higher glass fibre content FRP. FRP showed higher resistance to erosion damage than resin matrix at low angle of attack, the contrary tendency can be observed at higher angle of attack. The importance of damage of glass fibre bundles accompany with surrounding resin and effect of orientation angle of fibres on erosion damage of FRP were pointed out. Based on these factors and applying similar equation of the rule of mixture for strength of FRP, prediction method for erosion rate was proposed.By using this method, erosion rates of all types of GFRP under various angles of attack and impacting velocity can be estimated by knowing only the rate of matrix resin.     

Analysis of tutorial interactions

In this article the analysis of different interactions between learner and teaching programs is presented and discussed. The analysis is done in terms of a conceptual framework describing primitive learner and system actions at three different levels: (a) a didactic level, (b) a communication level, and (c) a media level. We conclude that this framework may not only be helpful in evaluating the functionality of teaching programs, but also in designing such programs.     

Improved modelling and control of oil and gas transport facility operations using artificial intelligence

In recent years, the application of artificial intelligence (AI) based techniques to a wide range of industrial processes has become increasingly common. One reason for this development is the level of maturity of both theory of AI concepts and its implementation into application tools for commercial use. Another very important reason is the persistent drive of many industries to increase efficiencies and the realisation that this requires more effective processing of gained knowledge and information. In the oil and gas industry, due to high saturation levels of many production fields and the complex nature of processes, the need for increased efficiencies and highly effective processing of a large amount of information is particularly evident. Some organisations have recognised the opportunities offered by AI-based techniques and started exploiting them in order to improve knowledge and information handling and process efficiencies. This paper discusses the application of two AI-based techniques, fuzzy logic and artificial neural networks (ANNs), to specific problems related to the operation of oil and gas transport facilities. The background for the work, which is carried out in a co-operation between a university and a leading engineering service provider, is described firstly. This is followed by a brief summary of the fundamentals of the AI techniques considered with respect to their use for industrial purposes. Then, two case studies are presented. The first case study demonstrates the application of fuzzy logic to the control of a pump station in a pipeline system whilst the second case study shows the use of an ANN for the determination of important pipeline characteristics. Problem backgrounds, design procedures and outlines for the implementation of the used AI techniques are given. Finally, benefits of the adopted approaches are highlighted and the wider impact on both industry and research community is discussed.     

Design of a furnace for refining copper prior to fusion

The design of a furnace for the removal of copper impurities prior to smelting is presented here. Impurities such as arsenic, antimony, bismuth, lead, and zinc are removed by heating the concentrate below 1000°C in an indirect way using the thermal energy from the gases of fusion and conversion. The concentrate heats up while sliding down along a hermetically sealed vacuum tunnel. After passing through filters, the volatilized substances are conducted along a tunnel with a decreasing temperature profile which induces a step-wise condensation and recovery of the different substances. The main operating cost of the furnace is due to the electric energy required by the vacuum pumps and the liquid air condensers. This cost turns out to be very small as compared to the overall operating cost of the smelter.     

Impact of support oxide and Ba loading on the NOx storage properties of Pt/Ba/support catalysts: CO2 and H2O effects

A series of 1 wt.%Pt/_xBa/Support (Support = Al₂O₃, SiO₂, Al₂O₃-5.5 wt.%SiO₂ and Ce_0.7Zr_0.3O₂, x = 5–30 wt.% BaO) catalysts was investigated regarding the influence of the support oxide on Ba properties for the rapid NO_x trapping (100 s). Catalysts were treated at 700 °C under wet oxidizing atmosphere. The nature of the support oxide and the Ba loading influenced the Pt–Ba proximity, the Ba dispersion and then the surface basicity of the catalysts estimated by CO₂-TPD. At high temperature (400 °C) in the absence of CO₂ and H₂O, the NO_x storage capacity increased with the catalyst basicity: Pt/20Ba/Si < Pt/20Ba/Al5.5Si < Pt/10Ba/Al < Pt/5Ba/CeZr < Pt/30Ba/Al5.5Si < Pt/20Ba/Al < Pt/10BaCeZr. Addition of CO₂ decreased catalyst performances. The inhibiting effect of CO₂ on the NO_x uptake increased generally with both the catalyst basicity and the storage temperature. Water negatively affected the NO_x storage capacity, this effect being higher on alumina containing catalysts than on ceria–zirconia samples. When both CO₂ and H₂O were present in the inlet gas, a cumulative effect was observed at low temperatures (200 °C and 300 °C) whereas mainly CO₂ was responsible for the loss of NO_x storage capacity at 400 °C. Finally, under realistic conditions (H₂O and CO₂) the Pt/20Ba/Al5.5Si catalyst showed the best performances for the rapid NO_x uptake in the 200–400 °C temperature range. It resulted mainly from: (i) enhanced dispersions of platinum and barium on the alumina–silica support, (ii) a high Pt–Ba proximity and (iii) a low basicity of the catalyst which limits the CO₂ competition for the storage sites.