Study of stress corrosion in aluminum alloys

Mechanism of the stress corrosion cracking of high-strength aluminum alloys was investigated using electrochemical, mechanical, and electron microscopic techniques. The feasibility of detecting stress corrosion damage in fabricated aluminum alloy parts by nondestructive testing was investigated using ultrasonic surface waves and eddy currents

Increased resistance to stress corrosion of aluminum alloys

Stress corrosion resistance is increased by distorting surface grain-boundary structure and by interrupting the corrosion and stress corrosion. The first is accomplished by machining or shot peening and the second by removal from and later reexposure to the corrosive environment

Feasibility study for a secondary Na/S battery

The feasibility of a moderate temperature Na battery was studied. This battery is to operate at a temperature in the range of 100-150 C. Two kinds of cathode were investigated: (1) a soluble S cathode consisting of a solution of Na2Sn in an organic solvent and (2) an insoluble S cathode consisting of a transition metal dichalcogenide in contact with a Na(+)ion conducting electrolyte. Four amide solvents, dimethyl acetamide, diethyl acetamide, N-methyl acetamide and acetamide, were investigated as possible solvents for the soluble S cathode. Results of stability and electrochemical studies using these solvents are presented. The dialkyl substituted amides were found to be superior. Although the alcohol 1,3-cyclohexanediol was found to be stable in the presence of Na2Sn at 130 C, its Na2Sn solutions did not appear to have suitable electrochemical properties

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

Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Quarterly report, 1 Dec. 1967 - 29 Feb. 1968

Stress corrosion of aluminum alloys and techniques for its detectio

Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Annual summary report, 2 Jun. 1967 - 1 Jun. 1968

Stress corrosion cracking of high strength aluminum alloys investigated by electrochemical, mechanical, and electron microscopic technique

Does export market concentration matter? A case study of uruguayan beef exports

70 p.As one of the 10 main world beef exporters, Uruguay with a relatively big beef industry, exports 80% of its total beef production. Even though beef production has always been a relevant sector in the Uruguayan economy, during the last 8 years strong growth in exports caused Uruguay to become competitive in the world beef market. Strong investment by the country’s beef industry significantly increased the harvest and processing capacity. Cattle harvesting records were set in 2005 and 2006. The export destinations of Uruguayan beef have been changing drastically during the last 8 years. The outbreak of FMD (Foot and Mouth Disease) in 2001 with the consequent closing of traditional markets, has determined new trade patterns and a different export destination mix. During 2005, 72% of the beef exports had the United States as destination, increasing the fear of dependence in one country. If a Geographic Diversification Index is calculated among the main world beef exporters, the results show that in 2005 the structure of the Uruguayan beef exports is the most concentrated among them. The described scenario constitutes a start at evaluating the actual Uruguayan export mix. This study aims to discuss whether the actual export market concentration makes Uruguay vulnerable and constitutes an economic problem and whether the government can, and should, attempt to diversify trade for economic reasons. The main research questions that emerge from the above situation and that guide the study are the following: 1. Should Uruguay follow its neighbours and also try to diversify? Or, should Uruguay continue to nurture the US and its growing demand? 2. Is it risky to have most of the eggs in one basket? Does it mean the export revenue is not stable and not growing? 3. Does concentration imply more export volume and revenue volatility than if Uruguay had a smaller share of its beef trade with the US? Will a diversification strategy of exports make Uruguay better off? 4. Who and what determine the trade patterns? Is it even feasible for the government to change the Uruguayan share of beef trade with the US? The paper is structured in three main sections besides the conclusions, references and appendix. The first section introduces the reader to the country giving a brief overview of the beef sector, emphasizing the beef industry characteristics as well as its domestic and export markets. The second part describes what is meant by diversification, and the reasons why it is so important. Then, the section exposes what has determined Uruguayan beef market structure and trade patterns to date, and an approximation of a possible future scenario for Uruguayan exports to the US is analyzed. Since geographic diversification is the main concern, the third section focuses on that preoccupation and assesses whether the current state of affairs is problematic from an economic point of view. To systematically describe the current trade mix and consider if it is problematic or too volatile, the concept of return versus risk in investment portfolios is applied to country trade portfolios. Export growth and export revenue are used as measures of return and export volatility as a measure of risk. Due to the fact that this analogy is not a perfect fit, one should not view this framework as providing a definitive answer about Uruguay’s optimal geographic export mix. Instead, it is a starting point to describe and assess the tradeoffs between trad

The importance of coffee tariff escalation on adding value at origin

95 p.The current structure of the coffee market and tariffs schedules observed in this study seems to support the economic theory in which tariff escalation inhibits imports of value added products. About 95% of exports from producing countries were in the form of green coffee with little value added and import tariffs were usually absent in developed countries’ markets. Additionally, less than one-fifth of 1% of the coffee exported from its origin was in roast and ground forms. Instant coffee constitutes roughly another 5%; in this case, a pattern of import tariff escalation is observed. Tariff escalation for bound and applied tariffs and the industry’s Effective Rate of Protection (ERP) created by such a tariff structure were evaluated for three major importing markets; EU, USA and Japan, which together account for 97% of world’s green coffee imports. Two important emerging markets, China and the Russian Federation, were also included in the evaluation. Six different exporting countries/regions, Brazil, Colombia, Central America, Vietnam, Ivory Cost and Indonesia, were chosen for this exercise for two reasons: first, they represented about 77% of the world’s exports on green coffee; second, due to their differences in geographical location, the coffee type produced and volume of production also differed and, therefore, they faced different market access treatment. The study concluded that although considerable reduction in importing duties has been achieved since the Uruguay Round Agreement on Agriculture, (URAA), all markets showed escalation in both bound and applied tariffs. Tariffs ranged from 0% (green coffee) to up to 30% for soluble and higher values for coffee preparations for which major markets such as USA and Japan also applied tariff quotas reaching Ad-valorem equivalents higher than 100%. The ERP estimates were significantly higher than nominal tariff wedges observed, reaching values in the range of 20 to 30% from green to roast in most of the markets. Green to soluble ERP on the other hand reached values between 70 to 90% for Japan and China; the EU showed values slightly higher than 30%. Although coffee tariff escalation was evident in coffee trade and the ERP caused as a result, was considerably high, a full removal of these tariffs barriers to trade does not necessarily imply that producing countries could easily add value at origin. Therefore, in order to make value added investment decisions, further studies should be undertaken to estimate the trade effect of full tariff removal. Key words: Tariff Escalation, Effective Rate of Protection, Tariff Wedges

Description of the policies applied and impact of credit on the agro chain food of conventional coffee in Costa Rican duringthe periods: 1998-1999 and 2000- 2001

133 p.The collapse of international agreements, brought as consequence disequilibrium in the international production and with it came a shortage of coffee supply, increasing international price until middles of 90?s. Costa Rica along with others Latina American countries have reacted to low supply and high coffee price, helping farmers to increase coffee production, the result from this effort was reflecting in the market only 4 years later due coffee has a particularly characteristics in it elasticity which is low in the long and short run in the supply side. Costa Rica banks doesn t have special interest rate for credits to coffee production Moreover interest rate has similarly values than industrial and service sector, may be due the strong position of coffee as commodity with high internal rate of return. National institutions looking forward to diminish the cost of transaction involve credits access that is why government allow processors to grant loan to producers, the principal guarantee that processors ask from producers is in behalf of their future coffee production, therefore this credits allow coffee producers to utilize the maximum inputs and factors of production in order to achieve high quality coffee production. PAM model help to describe how was the impact of agricultural politics in the production of coffee during the periods of production 1998 to 2001, showing the behaviour of the coffee agro chain, the data obtained for these evaluation came directly from ICAFE and the rest of information was asked directly to a different participant in the chain producers, processor, exporters and toasters. PAM analysis interpreted factor capital as factor of production without markets distortion and is not easy to calculate the low cost of transaction involve in loan granted by processors to producers to be include in the PAM model. But may be this transaction cost represented by the time involved in the all process of loan lease, processor do not face opportunity cost, because the direct grand of loan to producers, because they can set the same interest rate as commercial bank which is around 24%, the interest rate comprise from loan granted to harvest season around 7%. PAM analysis from farmers to exporters show clear inputs subsidy, that is reflected in inputs transfers indicator (J) due 10% fix quota policy on coffee for national consume, also this coffee tied to quota has national internal prices around 50 % low than international markets prices, this price add to the quota is reflected in PAM model as a income forgone, this lost is reflected in the outputs transfers (I) and price cost ratio index (PCR). The same situation is present in the valuation of PAM for the agro chain from farmers to toasters. Land factor was evaluated in PAM in both system of the agro chain; farmers to exporters and farmers to toasters, show that factor land, behave as constraint due the high markets prices and it is difficult for producers to expand their plantations. PAM model describe the rent of one hectare for coffee plantations as tax for coffee system, because is not present a marginal benefits from each hectare acquired, as it is show in the positive value of factors transfers (K) where the values for all four years were positive. The Subsidy Ration to Producers (SPR) explain that, from farmers to exports a high market distortion for coffee system, in average is - 0.23 from 1998 to 2000 and -0.69 in 2001, this distortion, could be caused by speculation in land value and this speculation based upon uncertainty in future prices of coffee, which means asymmetric price transmission. PAM model from farmers to toasters show also the higher taxation in the system of coffee and the distortion of (SRP) around 11% in 1998 and 1998 PAM model allow to analysis hypothetical scenarios. The first scenario was including an economic social valuation for land, taking as a value the income forgone for growth conventional coffee besides fair trade coffee, as result, the (SPR) diminished it values to -0.02 from 1998 to 2000, and -0.01 in 2001. The second scenario comprises the mentioned land valuation and hypothetical scenario, which assume that all farmers were involved in fair trade coffee. The result was a positive profitability and comparative advantage in the first two year likewise (SPR) index behave equal to the first scenario and (DCR) show a clear comparative advantage, due values are below one. Even when the next two years the indicators show a loss in profitability and comparative advantage, it is easy to recover this mislaid with a small increment in the output prices or a small adjustment to diminish cost of tradable inputs

Carbon monoxide detector

A sensitive carbon monoxide detector, developed specifically for spacecraft use, is described. An instrument range of 0 to 60 ppm CO in air was devised. The fuel cell type detector is used as a highly sensitive electrolysis cell for electrochemically detecting gases. The concept of an electrochemical CO detector is discussed and the CO oxidation behavior in phosphoric and sulfuric acid electrolytes is reported