Policy Endogeneity and the Effects of Trade on the Environment

This paper reviews recent work on the implications of endogenous policy for the effects of trade on the environment and the sustainability of renewable resource stocks. A recognition that pollution policy is endogenous has had a major impact on the trade and environment literature and has reversed some of the previously established empirical findings. Work on pollution has proceeded faster than work on renewable resources. I suggest some directions for future work in this area.pollution, international trade and the environment, renewable resources, globalization, Environmental Economics and Policy, International Relations/Trade,

Development of a refrigeration system for lunar surface and spacecraft applications

An evaluation of refrigeration devices suitable for potential lunar surface and spacecraft applications was performed. The following conclusions were reached: (1) the vapor compression system is the best overall refrigeration system for lunar surface and spacecraft applications and the single phase radiator system is generally preferred for earth orbit applications, (2) the vapor compression cycle may have some application for simultaneous heating and cooling, (3) a Stirling cycle refrigerator was selected for the manned cabin of the space shuttle, and (4) significant increases in payload heat rejection can be obtained by a kit vapor compression refrigerator added to the shuttle R-21 loop. The following recommendations were made: (1) a Stirling cycle refrigerator may be used for food freezer and biomedical sample storage, (2) the best system for a food freezer/experiments compartment for an earth orbit space station has not been determined, (3) a deployed radiator system can be designed for large heat loads in earth orbit

Salt stabilizer for preventing chlorine depletion and increasing shelf-life of potable water - A concept

Proposed concept, based on law of mass action uses addition of salt to increase chlorine ions produced in sodium hydrochlorite solutions, thereby increasing solution shelf-life. This technique is not costly. Usefulness will be determined by acceptability of salt in product undergoing long shelf-life

Space-suit carbon dioxide absorption system: A concept

Partial pressure of carbon dioxide within a space suit is maintained at safe levels by regenerating carbon dioxide with potassium hydroxide solution on board spacecraft or by portable units

The graceful exit in pre-big bang string cosmology

We re-examine the graceful exit problem in the pre-big bang scenario of string cosmology, by considering the most general time-dependent classical correction to the Lagrangian with up to four derivatives. By including possible forms for quantum loop corrections we examine the allowed region of parameter space for the coupling constants which enable our solutions to link smoothly the two asymptotic low-energy branches of the pre-big bang scenario, and observe that these solutions can satisfy recently proposed entropic bounds on viable singularity free cosmologies.Comment: 14 pages, 6 figures, JHEP class. Added new section on the classical correction and reference

Duality in cosmological perturbation theory

Cosmological perturbation equations derived from low-energy effective actions are shown to be invariant under a duality transformation reminiscent of electric-magnetic, strong-weak coupling, S-duality. A manifestly duality-invariant approximation for perturbations far outside the horizon is introduced, and it is argued to be useful even during a high curvature epoch. Duality manifests itself through a remnant symmetry acting on the classical moduli of cosmological models, and implying lower bounds on the number and energy density of produced particles.Comment: 14 pages, LATEX, no figure

Verification test results of Apollo stabilization and control systems during undocked operations

The results are presented of analysis and simulation testing of both the Skylark 1 reaction control system digital autopilot (RCS DAP) and the thrust vector control (TVC) autopilot for use during the undocked portions of the Apollo/Soyuz Test Project Mission. The RCS DAP testing was performed using the Skylab Functional Simulator (SLFS), a digital computer program capable of simulating the Apollo and Skylab autopilots along with vehicle dynamics including bending and sloshing. The model is used to simulate three-axis automatic maneuvers along with pilot controlled manual maneuvers using the RCS DAP. The TVC autopilot was tested in two parts. A classical stability analysis was performed on the vehicle considering the effects of structural bending and sloshing when under control of the TVC autopilot. The time response of the TVC autopilot was tested using the SLFS. Results indicate that adequate performance stability margins can be expected for the CSM/DM configuration when under the control of the Apollo control systems tested