Demonstration of some selected aquaculture technologies under farming system research in Jessore and Santahar, Bangladesh

BFRI evolved some selected aquaculture technologies viz. polyculture of carps in perennial ponds, monoculture of short cycled fish species (BFRI super strain) in seasonal ponds and prawn seed production through backyard hatchery system have been demonstrated under Farming System Research (FSR) component in Jessore and Santahar regions. Both polyculture of carps and monoculture of short cycled fish species technologies were tested in farmer's ponds in Kaium Kula village near Jessore town. In polyculture trials, seven species comprising of silver carp (Hypophthalmichthys molirrix), catla (Catla catla), rohu (Labeo rohita), grass carp (Ctenopharyngodon idellus), common carp (Cyprinus carpio), mrigal (Cirrhinus cirrhosus) and silver barb (Barbonymus gonionotus) were stocked @ 9,500 (ratio 6:2:4:2:1:5:5); 10,750 (ratio 6:2:4:2:1:5:5) and 12,000 (ratio 6:2:4:2:1:5:4) fish/ha respectively in ponds of T1, T2 and T3 having three replications of each. The mean highest fish production was 3,148 kg/ha in T3, followed by 2,899 kg/ha in T1 and 2,875 kg/ha in T2. Production of T3 was significantly different (P<0.05) than both T1 and T2, while there was no significant differences (P>0.05) between the production of T1 and T2. In case of trial of short cycled fish species, two treatments were tested: T1 (comprising of BFRI super strain of Nile tilapia, silver carp, common carp and silver barb; ratio 3:5:1:1) and T2 (having only BFRI super strain of Nile tilapia). Stocking density in both the treatments were same (20,000 fish/ha). In this trial average production was higher in T1 (2,743 kg/ha) than that of T2 (2,369 kg/ha) but the production figure in these two treatments was not significantly different (P>0.05). Demonstration of backyard prawn hatchery technology was tested at Santahar region of Bogra district, North-west part of Bangladesh. This hatchery consisted of three main components i) bio-filter, ii) rearing tank unit (chari) and iii) air blower/air pump unit. Plastic drum of 200-250 l capacity and cemented chari of 200-250 l capacity were used as bio-filter and larval rearing containers respectively. A 0.5 hp air blower with 6 aquarium air pump were used to operate the aeration system in the hatchery. Diluted sea water (10-12 ppt) made from brine solution (200-250 ppt) collected from salt-bed was used in the backyard hatchery system of hatching of eggs and rearing of larvae. Rearing of first stage zoea-larvae was reared in three rearing tanks following the stocking densities of 40, 50 and 60/l of water respectively. Production of post-larvae were 20±0.82, 22±1.12 and 28±1.63/liter of water in treatments I, II and III respectively in 38, 40 and 39 days rearing period.

Towards a process framework for assessing the potential value of technologies

Current technology valuation literature predominantly focuses on explaining the merits and implications of specific tools, but little research is available that takes a contextual process perspective. The aim of this paper is to further develop an integrative process framework that supports the structuring of the valuation process and the more systematic choice of valuation techniques for new technologies. The paper starts by reviewing key concepts and issues that surround the assessment of technology investments and the evidence of what companies use. Many factors need to be brought into the appraisal process, reflecting technological and market conditions. While there is usually a desire to reduce the assessment to a financial value, it is also widely appreciated that there is long term strategic value in securing a technological lead, which is difficult, or even inappropriate, to assess in purely financial terms. The multiple factors involved in the evaluation activity are identified with respect to the changing nature of the appraisal process as the technology matures and the implications for associated tools. The result of the literature review is a process framework which provides a conceptual basis for integrating valuation techniques. This framework is then populated with the results of industrial case studies on technology valuation to allow conclusions on its applicability to be drawn. © 2011 IEEE.

Why do firms acquire external technologies? Understanding the motivations for technology acquisitions

Why do firms acquire external technologies? Previous research indicates that there are a wide variety of motivations. These include the need to acquire valuable knowledge-based resources, to improve strategic flexibility, to experiment), to overcome organisational inertia, to mitigate risk and uncertainty, to reduce costs and development time in new product development, and the perception that the firm has the absorptive capacity to integrate acquisitions. In this paper we provide an in-depth literature review of the motivations for the acquisition of external technologies by firms. We find that these motivations can be broadly classed into four categories: (1) the development of technological capabilities, (2) the development of strategic options, (3) efficiency improvements, and (4) responses to the competitive environment. In light of this categorisation, we comment on how these different motivations connect to the wider issues of technology acquisition. © 2010 IEEE.

Comparison of quantum chemistry calculation methods of nucleic acid base-quartets

Nine base-quartets were calculated by six semi-empirical methods and ab initio Hartree-Fork method using STO-3G basis set. The results showed that PM3 method can be use to calculate base quartets, the results of PM3 calculations are close to the ab initio