Environmental impact assessment of the pangasius sector in the Mekong Delta

In the past seven years the export of white pangasius fillets grew fast. The culture method shifted to intensive production of striped catfish (Ca Tra) in deep ponds because this is more efficient than the pen and cage culture of Ca Basa. Today, striped catfish comprises more than 90 % of the culture. The increased production was achieved by producers investing in large ponds. The market chain is gearing towards vertical integration. Most farms keep fish at relatively high densities of 15 to 25 fish/m3 in ponds having a depth of up to 4m, and are advised to exchange daily 20 to 40% of the water. The sustainability of the sector is threatened due to the increased environmental pressure, and hampered by the growing cost of inputs and reduced farm-gate prices of the fish. The Environmental Impact Assessment (EIA) intends to identify measures for preventing or mitigating the environmental impacts of catfish culture in the Mekong Delta. The EIA was a seven-step process during which we interacted twice with part of the main stakeholders. To build trust among the stakeholders from the sector, we conducted the scoping and goal setting with them

FAMEBASE VER. 2.0 – Hệ quản trị cơ sở dữ liệu cho người sử dụng đầu cuối

FAMEBASE VER. 2.0 – Hệ quản trị cơ sở dữ liệu cho người sử dụng đầu cuối

The structural transition under densification and the relationship between structure and density of silica glass

The structure of silica glass (SiO2) at different densities and at temperatures of 500 K is investigated by molecular dynamics simulation. Results reveal that at density of 3.317 g/cm3, the structure of silica glass mainly comprises two phases: SiO4- and SiO5-phases. With the increase of density, the structure tends to transform from SiO4-phase into SiO6-phase. At density of 3.582 g/cm3, the structure comprises three phases: SiO4- , SiO5-, and SiO6-phases, however, the SiO5- phase is dominant. At higher density (3.994 g/cm3), the structure mainly consists of two main phases: SiO5- and SiO6-phases. In the SiO4-phase, the SiO4 units mainly link to each other via corner-sharing bonds. In the SiO5-phase, the SiO5 units link to each other via both corner- and edge-sharing bonds. For SiO6-phase, the SiO6 units can link to each other via corner-, edge-, and face-sharing bonds. The SiO4-, SiO5-, and SiO6-phases form SiO4- SiO5- and SiO6-grains respectively and they are not distributed uniformly in model. This results in the polymorphism in the silica glass at high density

WISCON. Teilthemen: Ereignisgesteuerte Inferenztechniken (EIT). T. 1 und 2 Ein Verfahren zur Regelinterpretation fuer Echtzeitprobleme (Inferenz-Without-Rules-Methode). Hybride Verfahren zur Echtzeitverarbeitung. Anwendungsbereich WERRA

Available from TIB Hannover: F98B623 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

WISCON. Teilthema: Methodenentwicklung fuer intelligentes Monitoring und Control, Wissensakquisitions- und Entscheidungsstrategien fuer dynamische Systeme Schlussbericht

The following tasks were treated within the framework of the project WISCON. The results are implemented in the tools, given in brackets: 1. Aquisition of knowledge for static plants, based on training examples (ILMWISSAK). 2. Aquisition of knowledge for dyanmic plants, based on training examples (ILMWISSAK). 3. Decision making for process control, based on classifiers (ILMKLASS). 4. Event controled interference (ILMREALEX). 5. Prototypical implementation of the developed methods and tools in the application field Werra (Consulting system 'WERRA'). Thus the knowledge based methods were integrated in an object oriented process control system. The main goal was the improvement of the quality of the process control tasks, especially: - Integration of conventional and knowledge based information processing, - online ability of knowledge based systems, - reasoning time depended situations (development of process situations), - knowledge based analysis of the input/output characteristic of technical and nontechnical plants and the resulting control strategies. (orig.)Available from TIB Hannover: D.Dt.F.QN1(17,53) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman