Single crystal tubes of beta alumina

Edge-defined, film-fed growth process allows both tubular shapes and single crystallinity to be achieved. Beta alumina in single crystal form makes possible membranes with improved conductivities. Single crystal membranes also eliminate problems associated with electrical short circuiting of membrane due to possible sodium metal diffusion

Ultralight reactive metal foams produced as structural shapes in space: System design

This autonomous experiment for foaming metals in space involved: (1) payload support structure; (2) furnace and foaming apparatus; (3) electronic controls; (4) battery power; and (5) metallurgy. Emphasis was laid on a modular design which was easily modifiable and which offered maximum durability, safety, and failure tolerance

MEETING PRIVATE GRADES AND STANDARDS IN TRANSITION AGRICULTURE: EXPERIENCES FROM THE ARMENIAN DAIRY INDUSTRY

One of the main trends emerging from the agroindustrialization process is the rise of 'grades and standards' (G&S) in food products. G&S were initially developed by the public sector to reduce transaction costs and ensure product quality and safety but have become a strategic instrument of competition in differentiated product markets (Reardon et al, 2001). Firms are using grades and standards to protect and develop brands in the international marketplace and in some cases to fill in for missing public standards. While producers in developed countries have the resources to meet these requirements, in developing countries these changes have tended to exclude small firms and farmers from participating in market growth, because of the implied investment requirements (Reardon et al, 2001). This is leading to already disadvantaged farmers in these countries being forced to produce basic subsistence food crops and become further excluded from the opportunity to join the global food industry. While past research has evaluated the effects and trends of G&S (Reardon, et al, 2001; Farina & Reardon, 2000; Reardon & Farina, 2002) the organizational structure to enable small farmers to meet these requirements has largely been overlooked. In this paper we use a theoretical contract enforcement framework to argue that private enforcement capital developed through the facilitation of an external aid agency can be an effective means for creating credible and sustainable relationships capable of meeting G&S. We draw upon theory from Cocks and Gow (2002), Oliver and Gow (2002) and Gow et al. (2000) to argue that in situations characterized by high discount rates and low reputation or trust levels (such as transition agriculture) that the use of a third party external enforcement agent can be used to provide the necessary linkage between the parties to facilitate transactions. Through the facilitation role of the external agency, private enforcement capital is developed between the firm and the farmers, opening the path for a sustainable mutually beneficial relationship. Empirical evidence is provided by the case of the United States Department of Agriculture Marketing Assistance Project (USDA MAP) in Armenia and its role in establishing farmer owned milk marketing cooperatives. By acting as an external facilitator in the initial establishment and ongoing development of milk supply cooperatives the USDA MAP has provided a solution to the dual market failure problems of reliable supply of the consistent quality of milk required by processors while enabling farmers access to markets and ensuring timely payment and therefore enabling farmers and firms to credibly contract for the collective marketing of their milk. Through the establishment of a unique and flexibly designed combination of leadership development, training in governance, financial management, dairy management, and quality improvement programs, the USDA MAP has assisted the groups in expanding the self enforcing range in such a manner that the cooperative should be capable of sustaining long term credible exchange relationships once the external agency withdraws. This is important as aid programs have often failed at ensuring sustainability once external management and financial support is removed. Data for this paper was collected through a series of semi-structured interview with USDA MAP staff, dairy processing firm managers, cooperative managers, and cooperative presidents during the fall of 2002, and over a two week period in March, 2003.Livestock Production/Industries,

MEETING PRIVATE GRADES AND STANDARDS IN TRANSITION AGRICULTURE: EXPERIENCES FROM THE ARMENIAN DAIRY INDUSTRY

Livestock Production/Industries,

Electron scattering and transport in liquid argon

The transport of excess electrons in liquid argon driven out of equilibrium by an applied electric field is revisited using a multi-term solution of Boltzmann's equation together with ab initio liquid phase cross-sections calculated using the Dirac-Fock scattering equations. The calculation of liquid phase cross-sections extends previous treatments to consider multipole polarisabilities and a non-local treatment of exchange while the accuracy of the electron-argon potential is validated through comparison of the calculated gas phase cross-section with experiment. The results presented highlight the inadequacy of local treatments of exchange that are commonly used in liquid and cluster phase cross-section calculations. The multi-term Boltzmann equation framework accounting for coherent scattering enables the inclusion of the full anisotropy in the differential cross-section arising from the interaction and the structure factor, without an a priori assumption of quasi-isotropy in the velocity distribution function. The model, which contains no free parameters and accounts for both coherent scattering and liquid phase screening effects, was found to reproduce well the experimental drift velocities and characteristic energies.Comment: 32 pages, 16 figures; minor corrections, added 1 figur

Public Facilitation of Small Farmer Access to International Food Marketing Channels: An Empirical Analysis of the USDA Market Assistance Program in Armenia

With the continued globalization, rapid channel consolidation, increasing technology, capital, food safety and private grades and standards requirements, many small scale agricultural and horticultural producers from transitional and developing countries are rapidly becoming excluded from international agri-food marketing system. Consequently, governments and international agencies alike are reevaluating the structure, form, and delivery of their assistance programs as they search to identify new delivery mechanisms that can overcome the weaknesses that their traditional programs face within this new business environment. Their challenge is to design programs that facilitate the establishment of economically viable and sustainable market relationships and business models between small-scale producers and the international food marketing system that provide these financially distress producers access to the technological know-how, market knowledge and access, and financial and productive resources required to successively compete. Recent Central and Eastern European (CEE) experiences indicate that foreign direct investment and the entry of multinational firms have successfully facilitated small farmers access to international marketing channels. By entering markets with sufficient capital to ensure contract enforcement and support investment, multinational firms can overcome the pervasive hold-up and underinvestment problems plaguing the sector thereby stimulating investment and growth in agricultural production (Gow & Swinnen, 1998; 2001; Walkenhorst, 2000; Dries & Swinnen, 2004). For numerous reasons access to sufficient foreign direct investment or multinational firms may not be an option for many countries. The obvious question therefore becomes, can an alternative third-party facilitation mechanism for stimulating agriculture be identified apart from the private solutions found in Central and East Europe? Glover and Kusterer (1990), Porter and Philips-Howard (1997), Coulter et al (1999), Eaton and Shepherd (2001), and Simmons (2001) allude to the benefits of public agencies in facilitating firm farmer relationships. However as of now the literature has not identified nor extracted the critical processes and factors required in the design, development and establishment of long-run economically viable and sustainable business models that facilitate small producers' access to international food markets. In this research we develop a theoretical model explaining the critical processes and factors involved in the public facilitation of the establishment of economically sustainable marketing relationships between small producers and agroprocessors in the presence of financial distress and absence of effective enforcement mechanisms. The USDA Market Assistance Program (MAP) in Armenia is used to empirically test the theoretical model as it provides a natural experiment. Aremina's recovery is similar to those observed in other CEE countries; however Armenia's agricultural sector has not experienced the recovery found elsewhere. A key constraining factor has been the lack of foreign direct investment initiated solutions so successfully employed elsewhere (World Bank, 1999; 2002). Without the presence of private solutions that can create self-enforcing relationships and encourage relationship specific investment, the Armenian agricultural sector has remained in a sub optimal equilibrium characterized by deep financial distress and a general lack of investment. The only sub-sectors that have seen growth any growth have had MAP facilitation support. Thus what is unique is that the MAP project appears to provide a public solution rather than a private solution to the problem, as in all the previous research (Gow & Swinnen, 1998; 2001; Foster, 1999; Gow et al, 2000; Walkenhorst, 2000; Dries & Swinnen, 2004; Cocks & Gow, 2003). In order to examine the phenomena of establishment and development of sustainable inter-organizational marketing relationships within the context of Armenian agriculture, the USDA MAP project, and the goat industry, we have used mixed methodological approach combining qualitative and quantitative data collection. Approximately 100 semi-structured interviews were conducted with farmers, industry representatives, local experts, and USDA MAP personnel. In additional, an extensive enumerated survey was implemented questioning 2000 farmers in five sectors over 2003 and 2004. Based upon the extensive interviews 12 different business models and facilitation processes used by the USDA MAP were identified and a suitable stratified survey frame was designed to test the differences between these models. The theoretical model and empirical results indicate that the third party public facilitator, USDA MAP, is critical in facilitating the initial development of the channel and identifying a value proposition in a downstream market. However, economic sustainability requires that the public agency remain an arms-length third party facilitator, rather than being the leader in the development of the channel and thus an integral cog in the channel. The actual development of the marketing channel should be led by an entrepreneur who possesses both the ability to develop the marketing channel and who is trusted by the local community. By leading the development of the channel the private enforcement capital that is created through the development of the channel is created between the entrepreneur and the farmers. Over time this widens the self enforcing range of the relationship, therefore allowing greater shifts in market conditions and decreasing the risk of opportunistic behavior (Gow et al, 2000). By holding the trust and respect of the community the entrepreneur inherently holds private enforcement capital with the rest of the community equivalent to the present value of their reputation or trust individually and collectively with the community (Oliver & Gow, 2002). Additionally, the expectation of a value proposition of a downstream market creates the expectation of private enforcement capital between farmers the entrepreneur through the present value of future returns that the entrepreneur could earn from the value proposition (Gow et al, 2000). Thus the combination of the present value of the entrepreneur's reputation with the farmers in the short term combined with the longer term expectation of future returns through the value proposition and creates sufficient private enforcement capital for the immediate development of a self-enforcing relationship with the farmers.International Relations/Trade,

Mud peeling and horizontal crack formation in drying clays

Mud peeling is a common phenomenon whereby horizontal cracks propagate parallel to the surface of a drying clay. Differential stresses then cause the layer of clay above the crack to curl up to form a mud peel. By treating the clay as a poroelastic solid, we analyse the peeling phenomenon and show that it is caused by the gradient in tensile stress at the surface of the clay, analogously to the spalling of thermoelastic materials. For a constant water evaporation rate at the clay surface we derive equations for the depth of peeling and the time of peeling as functions of the evaporation rate. Our model predicts a simple relationship between the radius of curvature of a mud peel and the depth of peeling. The model predictions are in agreement with the available experimental data available

Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Quarterly report, 1 May - 31 Aug. 1968

Mechanism of stress corrosion cracking in aluminum alloys and techniques for detection of surface defect

Accessibility of 3D Game Environments for People with Aphasia: An Exploratory Study

People with aphasia experience difficulties with all aspects of language and this can mean that their access to technology is substantially reduced. We report a study undertaken to investigate the issues that confront people with aphasia when interacting with technology, specifically 3D game environments. Five people with aphasia were observed and interviewed in twelve workshop sessions. We report the key themes that emerged from the study, such as the importance of direct mappings between users’ interactions and actions in a virtual environment. The results of the study provide some insight into the challenges, but also the opportunities, these mainstream technologies offer to people with aphasia. We discuss how these technologies could be more supportive and inclusive for people with language and communication difficulties