The Fantasticks (July 18-23, 25-30)

Program for The Fantasticks (July 18-23, 25-30)

Radioisotope Power: A Key Technology for Deep Space Exploration

A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future

Climate model and proxy data constraints on ocean warming across the Paleocene-Eocene Thermal Maximum

Constraining the greenhouse gas forcing, climatic warming and estimates of climate sensitivity across ancient large transient warming events is a major challenge to the palaeoclimate research community. Here we provide a new compilation and synthesis of the available marine proxy temperature data across the largest of these hyperthermals, the Paleocene-Eocene Thermal Maximum (PETM). This includes the application of consistent temperature calibrations to all data, including the most recent set of calibrations for archaeal lipid-derived palaeothermometry. This compilation provides the basis for an informed discussion of the likely range of PETM warming, the biases present in the existing record and an initial assessment of the geographical pattern of PETM ocean warming. To aid interpretation of the geographic variability of the proxy-derived estimates of PETM warming, we present a comparison of this data with the patterns of warming produced by high pCO2 simulations of Eocene climates using the Hadley Centre atmosphere-ocean general circulation model (AOGCM) HadCM3L. On the basis of this comparison and taking into account the patterns of intermediate-water warming we estimate that the global mean surface temperature anomaly for the PETM is within the range of 4 to 5°C

The Externalities Associated with Various Heating Sources at Bates College

The aim of this report is to determine the costs associated with the externalities of #2 fuel oil, natural gas, biomass, and renewable fuel oil. Externalities occur when a market transaction imposes costs on parties external to that transaction. These four energy sources are options Bates College is considering for heating its campus, either through the central steam plant or separate boiler systems. Evaluating the costs of these externalities will provide a picture of the true cost of energy, allowing the school to make a decision with complete information regarding the implications of using these energy sources. The methodology for estimating the cost of externalities differs for the two groups of energy sources. The values for #2 fuel oil and natural gas largely follow the methodology of the ExternE report of the European Commission, in which empirical modeling and case studies provide for the estimates of various externalities of fuel sources used across Europe. The findings of the ExternE report are supplemented with outside literature in order to confirm that the ExternE methodology is valid, and to provide additional externality cost information lacking in the report. This study finds that there are a range of externality costs associated with the use of #2 fuel oil and natural gas, from the costs of health effects to atmospheric pollution. Biomass and renewable fuel oil follow similar methodologies in terms of evaluating the costs of externalities. Various sources of literature are used to determine the possible mechanisms in which externalities may exist through the use of these energy types, and to determine their impact in terms of a monetary value. As these two energy sources are very recent additions to the market, reports beyond those available in the academic literature are also relied upon to provide information. One of the major contributors to externalities associated with renewable fuel oil is the Pacific Northwest National research Lab (PNNL). This report finds that the externality costs associated with biomass and renewable fuel oil are minimal compared to the other energy sources, as the primary externality costs are associated with the transportation of these materials. The results of this study are reported as lower bounds for fossil fuel externalities and upper bounds for renewable fuel externalities. By reporting the renewable fuel externalities as upper bounds, we can show the worst-case scenario associated with renewables. This will provide a contrasting figure to our minimum conservative values for fossil fuels that show the best-case scenario. These values are estimates due to our understanding that certain impacts cannot be valued monetarily given the complexity of the relationships among these energy markets, the economy, and the environment

UVM Tobacco Use and Attitudes After Implementation of a Tobacco-Free Policy

Introduction: Widespread public health initiatives have led to falling smoking rates. Currently, 1,620 U.S. colleges have adopted smoke-free policies. In August 2015, the University of Vermont (UVM) adopted a tobacco-free policy that bans all forms of tobacco use on university property. The purpose of this study was to compare tobacco use and attitudes before and after policy implementation.https://scholarworks.uvm.edu/comphp_gallery/1230/thumbnail.jp

Effect of Ultrashort Pulse Laser Structuring of Stainless Steel on Laser-based Heat Conduction Joining of Polyamide Steel Hybrids

AbstractThe objective of this paper is to investigate how microstructures generated by ultrashort pulse laser structuring of stainless steel affect the laser-based joining of thermoplastic metal hybrids. For structuring experiments a picosecond laser (λ = 064 nm) is used. The machined surfaces are topographically analyzed by optical microscopy. The experimental setup for the joining process consists of a disk laser (λ = 1030nm), a scanner optic and a clamping device for lap joint. The joined specimens are mechanically analyzed by tensile shear tests and the influence of ultrashort pulse laser structuring on the mechanical properties of the dissimilar joints is evaluated. Besides, a fracture analysis of the mechanically tested specimens using scanning electron microscope (SEM) images and energy dispersive X-ray spectroscopy (EDX) mapping is done