Model Calculations and Implementation of Filters and Hybrid Green VCSELs based on Optical Thin Film Stacks

This work introduced the novel conception of complex coupled hybrid VCSELs for the first time. Alternating organic and inorganic layers in the lasers provide periodic variation of refractive index and optical gain, which enable single mode operation and low threshold of the VCSELs. Model calculations revealed great reduction of the lasing threshold with factors over 30, in comparison with the existing micro-cavity lasers. Tunable green VCSEL has been also designed, implemented and analyzed taking advantage of the broad photoluminescence spectra of the organics. Free standing optical thin films without compressive stress are technologically implemented. Multiple membrane stacks with air gap in between have been fabricated for the implementation of complex coupled VCSEL structures. Complex coupled hybrid VCSEL is a very promising approach to fill the gaps in the green spectral range of the semiconductor lasers.

Factors influencing a conversion to organic farming in Nepalese tea farms

Organic agriculture in developing countries has increased in past decades especially due to the high demand of organic products in developed countries. The rate of conversion to organic production in Nepal, however, is observed much slower than expected. This study investigates factors that determine the conversion to organic production using Nepalese tea producers as a case study. A survey of 181 farmers was conducted in the Ilam and Panchthar district of Nepal, among which 86 were organic farmers and 95 were conventional farmers. A discriminant analysis was used to identify socio-economic characteristics that distinguish conventional and organic farmers. Results from the estimated discriminant function suggest that farmers located in a distance from regional markets, older in age, better trained, affiliated with institutions and having larger farms are more likely to adopt organic production. Similarly, a factor analysis shows that environmental awareness, bright market prospects, observable economic benefit and health consciousness are the major factors influencing farmers’ decisions on the conversion to organic production. While planning programs for the development of the organic tea sector in Nepal, policy makers should consider the support of farmers’ institutions, provision of training to farmers and raise farmers’ awareness about the environmental, economic and health benefits of organic farming.

‘Green Consumption’ beyond mainstream economy: A discourse analysis

In contemporary society, green consumption is a popular concept. The life styles of people and consumption behaviors are moderated in accordance to the ‘green ideology’. The process of green consumption can be observed through social behaviors such as preference of bio foods, recycling, reusing, limiting the over consumption and using environmentally friendly transport systems. However, mainstream economic analyses on green consumption argued that consumer behaviors are due to the rational choice of individuality based on utility and self-preferences. The hypothesis of this paper on consumer behavior in green consumption is configured by discourses according to the discourse analysis.

From Subsistence Agriculture to Commercial Enterprise: Community management of green technologies for resilient food production

The aim of this paper is to emphasize the capacity and resilience of rural communities in regard to sustainable food security by adopting innovative approaches to irrigation. The shift from subsistence to commercial agriculture is promoted as a means to sustainable development. An analysis of the efficacy of irrigation schemes in Zimbabwe suggests that, in terms of providing sustainable agricultural production, they have neither been cost-effective nor have they provided long-term food security to their beneficiaries. This is certainly true of Shashe Scheme and most others in Beitbridge District. The Shashe Irrigation Scheme project represents a bold attempt at developing a fresh approach to the management of communal land irrigation schemes through a Private Public Community Partnership. The model illustrated represents a paradigm shift from subsistence agriculture to a system based on new technologies, market linkages and community ownership that build resilience and lead to sustainable food security and economic prosperity.