Agricultural productivity growth in the Mediterranean and tests of convergence among countries

This paper measures agricultural productivity among a set of thirteen Mediterranean countries which includes two EU- 15 countries (Greece and Spain), another two EU- 25 (Cyprus and Malta) one country under accession negotiations (Turkey) and eight Middle East and North Africa (MENA) countries (Algeria, Egypt, Israel, Jordan, Libya, Morocco, Syria and Tunisia) from 1961 to 2002. The objective of the paper is twofold: Firstly, to analyse agricultural productivity growth in the Mediterranean countries by means of the sequential Malmquist Total Factor Productivity (TFP) index and secondly, to investigate whether this measure is converging among these countries. In terms of the first objective, TFP indices are decomposed into efficiency changes and technical changes, in an attempt to identify the best - practise countries and the overall effect of technological improvements. In terms of the second, both cross- section and time series tests of convergence are applied. The former include the conventional β- and σ- convergence tests, while for the latter, a new method proposed by Nahar and Inder (2002) that allows for country - specific estimates is used. Neither test finds evidence for unconditional convergence, but two distinctive periods, one prior and one after 1980 are recognized. The time series approach identifies four countries to be converging to the mean and another two to be diverging.Productivity growth, sequential Malmquist TFP, convergence., Productivity Analysis,

US ITER limiter module design

The recent U.S. effort on the ITER (International Thermonuclear Experimental Reactor) shield has been focused on the limiter module design. This is a multi-disciplinary effort that covers design layout, fabrication, thermal hydraulics, materials evaluation, thermo- mechanical response, and predicted response during off-normal events. The results of design analyses are presented. Conclusions and recommendations are also presented concerning, the capability of the limiter modules to meet performance goals and to be fabricated within design specifications using existing technology

APEX and ALPS, high power density technology programs in the U.S.

In fiscal year (FY) 1998 two new fusion technology programs were initiated in the US, with the goal of making marked progress in the scientific understanding of technologies and materials required to withstand high plasma heat flux and neutron wall loads. APEX is exploring new and revolutionary concepts that can provide the capability to extract heat efficiently from a system with high neutron and surface heat loads while satisfying all the fusion power technology requirements and achieving maximum reliability, maintainability, safety, and environmental acceptability. ALPS program is evaluating advanced concepts including liquid surface limiters and divertors on the basis of such factors as their compatibility with fusion plasma, high power density handling capabilities, engineering feasibility, lifetime, safety and R and D requirements. The APEX and ALPS are three-year programs to specify requirements and evaluate criteria for revolutionary approaches in first wall, blanket and high heat flux component applications. Conceptual design and analysis of candidate concepts are being performed with the goal of selecting the most promising first wall, blanket and high heat flux component designs that will provide the technical basis for the initiation of a significant R and D effort beginning in FY2001. These programs are also considering opportunities for international collaborations

Performance limits of fusion first-wall structural materials.

Key features of fusion energy relate primarily to potential advantages associated with safety and environmental considerations and the near endless supply of fuel. However, it is generally concluded that high performance fusion power systems will be required in order to be economically competitive with other energy options. As in most energy systems, structural materials operating limits pose a primary constraint to the performance of fusion power systems. It is also recognized that for the case of fusion power, the first-wall/blanket system will have a dominant impact on both the economic and safety/environmental attractiveness of fusion energy. The first-wall blanket structure is particularly critical since it must maintain high integrity at relatively high temperatures during exposure to high radiation levels, high surface heat fluxes, and significant primary stresses. The performance limits of the first-wall/blanket structure will be dependent on the structural material properties, the coolant/breeder system, and the specific design configuration. Key factors associated with high performance structural materials include (1) high temperature operation, (2) a large operating temperature window, and (3) a long operating lifetime. High temperature operation is necessary to provide for high power conversion efficiency. As discussed later, low-pressure coolant systems provide significant advantages. A large operating temperature window is necessary to accommodate high surface heating and high power density. The operating temperature range for the structure must include the temperature gradient through the first wall and the coolant system AT required for efficient energy conversion. This later requirement is dependent on the coolant/breeder operating temperature limits. A long operating lifetime of the structure is important to improve system availability and to minimize waste disposition

Alternate-fuel reactor studies

A number of studies related to improvements and/or greater understanding of alternate-fueled reactors is presented. These studies cover the areas of non-Maxwellian distributions, materials and lifetime analysis, a /sup 3/He-breeding blanket, tritium-rich startup effects, high field magnet support, and reactor operation spanning the range from full D-T operation to operation with no tritium breeding

MHD considerations for a self-cooled liquid lithium blanket

The magnetohydrodynamic (MHD) effects can present a feasibility issue for a self-cooled liquid metal blanket of magnetically confined fusion reactors, especially inboard regime of a tokamak. This pressure drop can be significantly reduced by using insulated wall structure. A self-healing insulating coating has been identified, which will reduce the pressure drop by more than a factor of 10. The future research direction to further quantify the performance of this coating is also outlined

MHD considerations for a self-cooled liquid lithium blanket

The magnetohydrodynamic (MHD) effects can present a feasibility issue for a self-cooled liquid metal blanket of magnetically confined fusion reactors, especially inboard regime of a tokamak. This pressure drop can be significantly reduced by using insulated wall structure. A self-healing insulating coating has been identified, which will reduce the pressure drop by more than a factor of 10. The future research direction to further quantify the performance of this coating is also outlined

Routes to sustainability in public food procurement: An investigation of different models in primary school catering

Increasingly, policymakers are setting ambitious goals for sustainability in public procurement, integrated across different pillars. Such ambitions are apparent in public catering services, where procurement models have been shifting towards greater localisation of supply chains and purchasing of more organically grown food. To date however, few studies have examined empirically what the impacts of different procurement models are across these multiple pillars of sustainability. This research aimed to fill the gap, by measuring and comparing the environmental, economic and nutritional outcomes of different models of school meals procurement. Case studies were undertaken of ten primary school meals services in five European countries, capturing different procurement model types. Results showed carbon emissions ranged from 0.95 kgs CO2e per meal in the lowest case to 2.41 kgs CO2e in the highest case, with adoption of low carbon food waste disposal methods and reduction of the amount of ruminant meat in the menus being the most important actions for lowering emissions. In terms of economic impact, local economic multiplier ratios ranged from 1.59 to 2.46, and although the level of local food sourcing contributed to these ratios, the effect was eclipsed, in some cases, by investment in local catering staff. Meanwhile, implementation of a robust standards regime and improving canteen environment and supervision were the most important actions for nutritional quality and intake. The paper discusses the implications of the findings for integrated, sustainable models of food procurement