Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to ...assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather, management and soil data, and upscaled to the whole country. We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48–63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw. With 50% Yg closure and for various land use changes, self-sufficiency ratio will be >1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for rice and all three cereals jointly but below one for maize and wheat for all scenarios, except for the scenario with drastic decrease in boro rice area to allow for area expansion for cash crops. Full Yg closure of all cereals is needed to compensate for area decreases and demand increases, and then even some maize and large amounts of wheat imports will be required to satisfy demand in future. The results of this analysis have important implications for Bangladesh and other countries with high population growth rate, shrinking arable land due to rapid urbanization, and highly vulnerable to climate change.
•Relative yield gap (Yg) across water regime is around 45% (maize and wheat) and 50-60% (rice) in Bangladesh.•Relative Yg of three cereals is about 46-50% (under irrigation) and 40-63% (under rainfed).•With 50% Yg closure, self-sufficiency ratio (SSR) in 2050 will be ~ 1 (rice) but significantly<1 (maize and wheat).•With full Yg closure, SSR in 2050 will be greater than 1 (rice) but less than 1 (maize and wheat).•Full Yg closure in future can compensate area decrease in rice but some maize and large wheat imports will be inevitable.
Abstract
This article focuses on the contemporary back‐to‐the‐land migration of permaculture practitioners in post‐socialist (1989–) Czechia. It explores the ideals and practices of self‐sufficiency ...among back‐to‐the‐land migrants as they relate to their migration motives and post‐migration life, including the fulfilment of a dream of self‐sufficiency and local community integration. This article deals with individual in‐rural migrant projects and the experiences of permaculturists who live in intentional eco‐communities. It draws upon data from in‐depth interviews with back‐to‐the‐land migrants and analysis of documents and field notes. The article concludes that the self‐sufficient vision, part of a ‘family homestead’ concept promoted by permaculture teachers, is difficult to achieve for rural newcomers who must reformulate their visions to match the lived reality. The post‐migration life of this group is further complicated by disillusionment with local community relations and difficulties integrating within their migration destination because of their distinctive lifestyle. Czech back‐to‐the‐land migration related to permaculture differs from its western version in its inclination towards nature‐based spirituality and a specific land structure still influenced by the forced collectivisation of the communist era.
Biocatalysis has widened its scope and relevance since new molecular tools, including improved expression systems for proteins, protein and metabolic engineering, and rational techniques for ...immobilization, have become available. However, applications are still sometimes hampered by low productivity and difficulties in scaling up. A practical and reasonable step to improve the performances of biocatalysts (including both enzymes and whole-cell systems) is to use them in flow reactors. This review describes the state of the art on the design and use of biocatalysis in flow reactors. The encouraging successes of this enabling technology are critically discussed, highlighting new opportunities, problems to be solved and technological advances.
Biocatalyzed reactions with different classes of enzymes can be implemented with the integration of flow reactor technology, potentially leading to sustainable and highly productive continuous processes.
The combination of biocatalysis and flow chemistry opens the door to extensive application in cascade reactions.
Biocatalyzed flow reactions can occur either in monophasic flow or in segmented (slug) flow, where two or more immiscible phases are present.
Limitation of substrate/product inhibition effects, in-line purification with easy recovery of the product, and no mechanical mixing are among the most distinctive advantages of flow-based biocatalysis.
Automated machines and devices for in-line product recovery are now available at relatively low prices, making flow-based biocatalysis an easy-to-use technology.
The industrial process of drinking water treatment requires intensive energy, leading to high enterprise costs and abundant carbon emissions. To ensure cost-effective and low polluting power supply ...for the above process, this paper proposes to deploy the grid-connected hybrid renewable system. A multi-objective nonlinear dynamic model mixed with integer variables is established for the decision makers, in which both system configurations and operations as well as benefits trade-offs from four dimensions are simultaneously considered. The ε-constraint method and system planner attitude parameters are introduced to transform the proposed model into its equivalent single objective form, which is further been solved by the LINGO software. A case study in China is given to assess the viability of the proposed model, in which optimal system configuration, economically feasible self-sufficiency ratio and optimal energy balance are obtained. Influences of electricity pricing strategies and natural resource changes on the systems are also analyzed and compared. It is found that the deployment of grid-connected hybrid wind/PV/storage system can help power users to cope with the future electricity price variation risks, with the feasible self-sufficiency ratio reaching 95%.
•A hybrid renewable system for drinking water treatment plant is proposed.•An optimization model and analysis paradigm are provided for potential appliers.•Real case proved the economically feasible self-sufficiency ratio can reach 95%.•Deployment of above system helps to cope with the electricity price variation risk.
•Simulation model to analyse profitability of household PV and storage investments.•Consideration of technological, market-based, political and geographical drivers.•Comparison of PV-based ...self-consumption and self-sufficiency in Germany and Ireland.•Household electricity demand from grid may fall to 25% in Germany/35% in Ireland.•Strong self-sufficiency incentives in Germany may lead to distributional challenges.
Many countries introduced subsidy schemes that were successful in incentivising investments into residential solar PV. The resulting growth of the global PV market was accompanied by cost reductions for PV systems, reductions of PV subsidies and, often, increasing electricity retail prices. Along with decreasing costs for battery storages, these developments made self-consumption and self-sufficiency continuously more attractive. However, the profitability of PV-storage systems depends on many factors, including technological, political and geographical aspects. We present a simulation model to identify the most profitable sizes of PV and storage systems from a household perspective and explore what drives the profitability of self-consumption and self-sufficiency. We compare and contrast Germany and Ireland to account for regulatory and geographical differences. Our results show that PV-storage systems are generally profitable in Germany and that, after minor technology cost reductions, this result holds even in the absence of subsidies. In Ireland, such systems are not yet profitable but this may change soon with expected technology costs reductions. The share of electricity demand that will be required from the grid may be reduced to 25–35%. Implications for the electricity retail business and policy makers are discussed including distributional concerns and system efficiency considerations.
Abstract
This article focusses on an examination of Epicurus’ understanding of self-sufficiency, which is only marginally addressed within research. But many traditions suggest paying more attention ...to the concept of self-sufficiency. The scarcity of available sources must be regarded as problematic; therefore here an attempt is made to reconstruct this concept. The thesis is that Epicurus discusses human striving for self-sufficiency in two different ways and thus more comprehensively than previously assumed: extrinsic (physical or external autarky) and intrinsic (psychic or internal autarky). As so often, Epicurus is not talking about a theory, but about an immediate practice: human striving for self-sufficiency, an indispensable prerequisite for ataraxia, is made possible by living (hiddenly) in the garden in friendship—far from the politics of the polis. These connections lead to the conclusion that the individual self-sufficiency of the human being does not aim at ‘not needing anybody else anymore’, but requires a form of community that should allow the human being the greatest possible freedom within the framework of the Epicurean teachings.
The study is to investigate psychological self-sufficiency—the force within someone that activates cognitive and non-cognitive process of shifting perceived barriers into hope actions—as it relates ...to economic self-sufficiency among jobseekers with mental health barriers. Among a sample of 2455 low-income jobseekers in job readiness programs at six community-based agencies in Chicago, a subsample of 424 who self-identified as having mental illness barriers are selected to analyze the relationships between employment hope, employment barriers, and economic self-sufficiency using structural equation modeling. Results indicate that employment hope mediates the path between perceived employment barriers and economic self-sufficiency. The study further highlights the positive effects of employment barriers on employment hope among jobseekers with perceived mental illnesses. The findings support growing evidence that psychological self-sufficiency is positively associated with gaining economic self-sufficiency in workforce development programs.
Homeless service systems have been implementing assessment tools to inform service provision for individuals and families. Although a variety of assessments are available, their psychometric evidence ...base is limited. The self‐sufficiency matrix (SSM) is one assessment that demonstrates promising reliability and validity. However, the SSM's factor structure has been inconsistent across studies. This study explored the factor structure of the SSM, using exploratory factor analysis and confirmatory factor analysis in a sample of individuals (N = 427) and families (
N = 428) at risk of or experiencing homelessness. Data were derived from a midwestern city's Homeless Management Information System and included all participants from the Homelessness Prevention and Rapid Re‐Housing Program. Results suggest the SSM is multidimensional and the factor structure differs across individuals and families. Additionally, the SSM demonstrates measurement invariance across racial and gender groups. Further development and testing of the SSM is necessary to better serve individuals experiencing homelessness.
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