A 1987 overview of free-piston Stirling technology for space power application

An overview is presented of the NASA Lewis Research Center free-piston Stirling engine activities directed toward space-power application. NASA Lewis serves as the project office to manage the newly initiated NASA SP-100 Advanced Technology Program. One of the major elements of this five-year program is the development of advanced power conversion concepts of which the Stirling cycle is a viable growth candidate. Under this program the status of the 25 kWe opposed-piston Space Power Demonstrator Engine (SPDE) is presented. Included in the SPDE discussion are comparisons between predicted and experimental engine performance, enhanced performance resulting from regenerator modification, increased operating stroke brought about by isolating the gas bearing flow between the displacer and power piston, identifying excessive energy losses and recommending corrective action, and a better understanding of linear alternator design and operation. Technology work is also conducted on heat exchanger concepts, both design and fabrication. Design parameters and conceptual design features are also presented for a 25 kWe, single-cylinder free-piston Stirling space-power converter

Agricultural markets and risks - management of the latter, not the former

The authors review the historical relationship between the work of applied economists, and policymakers, and the institutions that came to characterize the commodity, and risk markets of the 1980s. These institutions were a response to the harmful consequences of commodity market volatility, and declining terms of trade. But the chosen policies, and instruments relied on market interventions, to directly affect prices, or the distribution of prices in domestic, and international markets. For practical, and more fundamental reasons, this approach failed. The authors next discuss how a growing body of work, contributed to a change in thinking that moved policy away from stabilization goals, toward policies that emphasized the management of risks. They distinguish between the macroeconomic effects of volatile commodity markets, and the consequences for businesses, and households. The authors argue that both sets of problems remain important development issues, but that appropriate policy instruments are largely separate. Nonetheless, because governments, households, and firms must all respond to a wide range of sources of risk, they emphasize the role for an integrated policy by government. Increasingly, alternative approaches have come to rely on market-based instruments. Such approaches accept the market view of relative prices as immutable, but address directly the negative consequences of volatility. As traditional risk markets (such as futures and insurance markets) expand, and new parametric markets emerge, the practicality of applying market-based instruments to traditional risk, and development problems increases. The authors show the change in approaches to risk, and the reliance on old, and new market instruments, with new, and sometimes experimental programs, with special emphasis on programs at the World Bank.Labor Policies,Payment Systems&Infrastructure,Health Economics&Finance,Environmental Economics&Policies,Insurance&Risk Mitigation,Environmental Economics&Policies,Insurance&Risk Mitigation,Health Economics&Finance,Banks&Banking Reform,Financial Intermediation

A New Electronic Coulometer for Electroanalytical Chemistry

The failure of electroanalytical chemistry to apply extensively the principles of Faraday\u27s laws, has been due primarily to the lack of a direct reading coulometer. The author has investigated several methods of current integration and has concluded that a direct current amplifier with a feedback capacitor shows best promise as a coulometer

Chronic toxicity of inhaled thymol in lungs and respiratory tracts in mouse model.

Epinephrine HFA (Primatene® Mist) is a newly formulated asthma metered dose inhaler developed to replace the previous Primatene® Mist CFC. The formulation of Epinephrine HFA contains thymol, a substance recognized to be safe by the FDA. Although the content of thymol contained in Epinephrine HFA is much lower compared to many common foods and medications available, there are no known nonclinical data about the chronic toxicity of thymol through inhalation. Two sequential 6-month studies of identical design were conducted to assess the chronic toxicity of inhaled thymol in mice. Four treatment groups, (a) Air; (b) vehicle control; (c) Article-1 (thymol 0.1%); and (d) Article-2 (thymol 0.5%) were assessed in 128 mice for 26 weeks. The mice were sacrificed at the end of the treatment period and a histopathologic evaluation was performed with respect to lungs, bronchial lymph nodes, nasal passages/nasopharynx, and trachea. Forty-five pathologic assessment parameters (PAPs) were evaluated. In total, 5591 data points from 487 mouse organs were assessed. Chronic toxicity index was calculated for 16 PAPs that had multiple histopathologic abnormal observations. The t tests were conducted for these 16 PAPs (Articles-1 and 2 versus Air and vehicle control, respectively), and all P-values were greater than .05 indicating no significant differences between all treatment groups. An evaluation was also conducted for 25 PAPs that had only a very small number of pathologic abnormalities. No significant differences for chronic toxicity were found when comparing mice under long-term repeated exposure of high doses of inhaled thymol and mice that inhaled no thymol

Functional Hyperaemia of Skeletal Muscle

1. Blood flow was recorded through the cat gastrocnemius and soleus muscles at rest and during stimulation at physiological frequencies. Deficiencies in the experimental set-up are discussed and the results compared with the findings of other workers who have recorded blood flow through "fast" and "slow" muscle. 2. ATP and adenosine were shown to be vasodilators of the vascular bed of the cat gastrocnemius and soleus muscles. Potassium, hypertonic glucose and inorganic phosphate were not vasodilator. These findings are discussed in relation to the identity of the vasodilator agent in functional hyperaemia of skeletal muscle. 3. ATP was detected in the plasma and Krebs perfusate from the resting and stimulated cat soleus muscle. This is discussed in relation to the hypothesis that ATP could be the vasodilator agent in functional hyperaemia. 4. APT was shown to be rapidly removed from cat blood in vitro. This is discussed in relation to a possible extracellular role for ATP

The Adoption of Generative Customization as an Innovation Strategy in the U.S. Smartphone Market: A Case Study

With the pace of change and adoption of new products continuing to escalate, even leading edge companies are facing challenges in retaining market leadership. In this case study, the frustration of a talented product designer for a U.S. leader in Smartphone technology leads to bigger questions about his firm’s willingness and ability to adopt a new IT-enabled innovation in product design and generative customization. He enlists the aid of an IT support analyst to help convince his organization to consider this new approach to extend and expand the company’s existing significant sales growth and market dominance in an increasingly competitive environment. The company must also understand the impact on product design of human cognitive creativity leveraged by an emerging technology, the viability of its closed system model of innovation, and the organizational challenges associated with market volatility and innovation

Pharmacokinetic study of thymol after intravenous injection and high-dose inhalation in mouse model.

Thymol is generally recognized as a safe substance by the FDA and has been widely used in the pharmaceutical, food, and cosmetic industries. Pharmacokinetic (PK) studies of thymol have been previously conducted for oral administration, but there has been no PK study for inhalation administration or intravenous (IV) injection. This study aims at exploring and comparing the inhalation and IV PK profile of thymol in a mouse model. The inhalation PK for mouse model was corrected with fur/skin absorption. Thirty-two male CD-1 mice were randomized into two study arms, Arm-A for intravenous (n = 16) and Arm-B for inhalation (n = 16). The amount of thymol in the mouse serum was measured for Arm-A and for Arm-B at the highest dose. Furthermore, 48 mice were utilized for fur/skin absorption of thymol. In total, 320 mouse serum samples for thymol were analyzed by LC/MS method. After inhalation, the peak concentration of thymol in mouse serum was 42.3 ng/mL (Cmax ) and occurred at 2 minutes (tmax ). The AUC of the inhaled thymol at 0-60 minutes (AUC0-60) was 464 ng/mL/min. From 10-60 minutes post-dose, the PK inhalation curve appeared to be higher than that for the IV injection. This is likely attributed to the effect of absorption of thymol through the fur/skin of mice. After an adjustment by fur/skin absorption, the PK profile for net inhalation closely matched the two-compartment model. In fact, the bioavailability for the net inhalation of thymol was 74% and 77% relative to that for IV injection per AUC0-60min and AUC0-infinite, respectively