Collaborative Learning is an effective activity-based, constructivism-based and experience-based learning method. Recently, various computer and network supported educational environments are incorporating collaborative learning activities. In order to design, develop and select effective collaborative learning systems it is necessary to consider quality requirements. This paper presents the CL...

Anaerobic co-digestion technology is increasingly used to simultaneously treat solid and liquid organic waste to balance nutrient content, to reduce the negative effects of toxic compounds in the process, and to increase biogas yield. The aim of this study was to analyze the economic performance of co-digestion plants fed with agro-industrial wastes as a function of installed power, with a meth...

This paper evaluates the thermodynamical, economical and environmental characteristics of a cogeneration system composed of a gas turbine and a waste heat boiler (System A). Two other systems for increasing power generating efficiency are also evaluated, namely systems B and C, which are constructed by incorporating a regenerative cycle and a dual fluid cycle, respectively, into Systen A. It ha...

The paper outlines a technical and economical comparison of two power collection concepts for off-shore wind farms: an innovative distributed concept versus the commonly used centralized power collection. In contrast to centralized power collection on a single and large platform, integrated and compact switchgear and transformer modules enable the distribution of power collection across multipl...

Cultivation of an important sub alpine-alpine medicinal and aromatic herb, Angelica archangelica Linn. (Apiaceae), was carried out at two different climatic zone at 2200 m asl (Pothivasa, PV) and 3600 m asl (Tungnath, TN) altitudes in Garhwal, North west Himalaya, India. These altitudes represent temperate and alpine region of the Himalaya. Since the species has a very few wild populations, cul...