Household air pollution among women using biomass stoves in Honduras: exposure characterization and associations with exhaled nitric oxide and markers of systemic inflammation

2018 Summer.Includes bibliographical references.To view the abstract, please see the full text of the document

A Case Study of the Ethanol CleanCook Stove Intervention and Potential Scale-Up in Ethiopia

Background Approximately 80% of Ethiopia\u27s energy consumption is dominated by woody biomass fuel use, resulting in 91.2 million tons of firewood and 4.2 million tons of charcoal consumed annually. Ethiopia\u27s dependency on non-sustainable energy, especially for cooking, has been a major concern for the nation for the past 30 years, contributing to deforestation, climate change, and adverse human health impacts. Objectives Our objective was to document the work of Gaia Association and the implementation of the ethanol CleanCook stove in the refugee camp and urban settings of Ethiopia. We then assessed the potential for the scale-up of ethanol as a household fuel. Methods We utilized the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework to evaluate the effectiveness and sustainability of the ethanol cookstove intervention. We obtained secondary data from a variety of sources to evaluate a.) The performance of the CleanCook ethanol stove; b.) Effectiveness of the ethanol cookstove implementation; and, c.) Barriers to scale-up and commercialization of ethanol use as a household fuel. In addition, we conducted primary analysis of qualitative surveys to evaluate the perceptions of the ethanol and adoption of the CleanCook stove. Results Our case study results provide critical insight into the 13-year implementation of the CleanCook ethanol stove in Ethiopia. Laboratory tests demonstrate that the CleanCook stove reduces harmful emissions compared to biomass stoves, and preliminary field tests show 24-hour average PM2.5 levels of 200 μg/m3. To-date 8731 CleanCook stoves were distributed to refugee households, while an additional 500 were sold at a subsided price to low-income urban households. CleanCook stove users report the continued use of multiple stoves. Conclusions The CleanCook ethanol stove has been implemented as an energy intervention for the vulnerable refugee population in Ethiopia for over 13 years. There has been limited success of a subsidized CleanCook stove among low-income households in Addis Ababa. This case study demonstrates the complexities of promoting a new fuel for household cooking, and the numerous obstacles and stagnations in implementation. Ethanol demonstrates some potential for scale-up and commercialization as a household fuel in Addis Ababa, but it may require simultaneous stabilization of ethanol supply, growth of a city-wide distribution infrastructure, and an affordably priced stove and fuel

Detailed Calculation of Test-Mass Charging in the LISA Mission

The electrostatic charging of the LISA test masses due to exposure of the spacecraft to energetic particles in the space environment has implications in the design and operation of the gravitational inertial sensors and can affect the quality of the science data. Robust predictions of charging rates and associated stochastic fluctuations are therefore required for the exposure scenarios expected throughout the mission. We report on detailed charging simulations with the Geant4 toolkit, using comprehensive geometry and physics models, for Galactic cosmic-ray protons and helium nuclei. These predict positive charging rates of 50 +e/s (elementary charges per second) for solar minimum conditions, decreasing by half at solar maximum, and current fluctuations of up to 30 +e/s/Hz^{1/2}. Charging from sporadic solar events involving energetic protons was also investigated. Using an event-size distribution model, we conclude that their impact on the LISA science data is manageable. Several physical processes hitherto unexplored as potential charging mechanisms have also been assessed. Significantly, the kinetic emission of very low-energy secondary electrons due to bombardment of the inertial sensors by primary cosmic rays and their secondaries can produce charging currents comparable with the Monte Carlo rates.Comment: 31 pages, 18 figures, 4 tables. to be published in Astroparticle Physics. Changed due to error found in normalisation of the simulation result

A thermal/nonthermal approach to solar flares

An approach for modeling solar flare high-energy emissions is developed in which both thermal and nonthermal particles coexist and contribute to the radiation. The thermal/nonthermal distribution function is interpreted physically by postulating the existence of DC sheets in the flare region. The currents then provide both primary plasma heating through Joule dissipation, and runaway electron acceleration. The physics of runaway acceleration is discussed. Several methods are presented for obtaining approximations to the thermal/nonthermal distribution function, both within the current sheets and outside of them. Theoretical hard x ray spectra are calculated, allowing for thermal bremsstrahlung from the heated plasma electrons impinging on the chromosphere. A simple model for hard x ray images of two-ribbon flares is presented. Theoretical microwave gyrosynchrotron spectra are calculated and analyzed, uncovering important new effects caused by the interplay of thermal and nonthermal particles. The theoretical spectra are compared with observed high resolution spectra of solar flares, and excellent agreement is found, in both hard x rays and microwaves. The future detailed application of this approach to solar flares is discussed, as are possible refinements to this theory

Ultra-high vacuum compatible induction-heated rod casting furnace

We report the design of a radio-frequency induction-heated rod casting furnace that permits the preparation of polycrystalline ingots of intermetallic compounds under ultra-high vacuum compatible conditions. The central part of the system is a bespoke water-cooled Hukin crucible supporting a casting mold. Depending on the choice of mold, typical rods have a diameter between 6 mm and 10 mm and a length up to 90 mm, suitable for single-crystal growth by means of float-zoning. The setup is all-metal sealed and may be baked out. We find that the resulting ultra-high vacuum represents an important precondition for processing compounds with high vapor pressures under a high-purity argon atmosphere up to 3 bar. Using the rod casting furnace, we succeeded to prepare large high-quality single crystals of two half-Heusler compounds, namely the itinerant antiferromagnet CuMnSb and the half-metallic ferromagnet NiMnSb.Comment: 5 pages, 4 figure

Human-Wildlife Conflict, Interspecies Disease, and Justice in a Wild-Life Rich Region in Kenya

Central Kenya’s Laikipia district is known for its significant wildlife numbers and biological diversity. This is the result of the commitment of community residents to protect wildlife populations, including those on private land. Despite successes, tensions between humans and wildlife remain. Most research to date has focused on conflict between pastoralist herders, particularly Maasai, and two wildlife species: elephants and lions. It has also focused on conflict resulting from depredation, property damage, and human injury. This study explores another potential contributor to negative attitudes toward wildlife: interspecies disease, and particularly the perception that wildlife can transfer disease to pastoralists’ domestic animals. Formal interviews were conducted with 64 Maasai pastoralists. Questions focused on experiences with disease in domestic animals, perceptions of wildlife contributions to domestic animal disease, and broader attitudes toward wildlife, and these issues are considered against the social, cultural, and historical background of the region. Interviews supported the commonly held belief that livestock disease places severe burdens on East African pastoralists. Different diseases were associated to varying degrees with wildlife; elephants, Cape buffalo, and zebra were most often cited as causing disease in domestic animals. Epidemiological studies confirm several associations that pastoralists made between wildlife and disease in domestic animals, and instances where assumptions and perceptions were not epidemiologically correct were still logically coherent. Persons who took part in this study did not list wildlife disease, or disease threats, as their greatest problem with wild species. However, responses also suggest that it would be a mistake to underestimate the impact that concerns about disease have on pastoralists’ attitudes toward wildlife.  Master of ScienceNatural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/96190/1/benka thesis final.pd

Aerodynamic Borne Noise of Passenger Cars

Medzi najviac diskutované problémy v dnešnom automobilizme považujem otázku ekonomiky a takisto aj emisie vzniknuté prevádzkou osobného automobilu. Trendom je tlačenie emisií a prevádzkových nákladov smerom nadol. Existuje niekoľko možných riešení ako dosiahnuť vyššej efektivity. Najviac využívaný je takzvaný downsizing, kedy je zmenšovaný zdvihový objem valcov motora pri zachovaní výkonnostných charakteristík. Toto má však efekt na životnosť motora a preto sa niektoré automobilky snažia od tohto trendu upustiť. V tejto práci budem pojednávať o problematike hluku vozidla, jeho zdrojov, pričom sa zameriam najmä na aerodynamický hluk osobného automobilu, možnostiach ako ho znížiť a rozoberiem ako sa bude tento trh vyvíjať v budúcnosti.Among the most discussed problems in today's motor mechanics I considers the issue of the economy and also the emissions resulting from the use of cars. The trend is pushing emissions and operating costs down. There are several possible solutions to achieve greater efficiency. The most used is the so-called downsizing when the reduction of cylinder capacity while maintaining performance characteristics remain or even improve. This has the effect on the life of the engine and therefore some automakers try to refrain from this trend. In this thesis I will discuss the issue of vehicle noise, its resources focusing mainly on aerodynamic noise of a passenger car, the possibilities to reduce it and discuss how this market will develop in the future.

Direct Robot Configuration Space Construction using Convolutional Encoder-Decoders

Intelligent robots must be able to perform safe and efficient motion planning in their environments. Central to modern motion planning is the configuration space. Configuration spaces define the set of configurations of a robot that result in collisions with obstacles in the workspace, C-clsn, and the set of configurations that do not, C-free. Modern approaches to motion planning first compute the configuration space and then perform motion planning using the calculated configuration space. Real-time motion planning requires accurate and efficient construction of configuration spaces. We are the first to apply a convolutional encoder-decoder framework for calculating highly accurate approximations to configuration spaces. Our model achieves an average 97.5% F1-score for predicting C-free and C-clsn for 2-D robotic workspaces with a dual-arm robot. Our method limits undetected collisions to less than 2.5% on robotic workspaces that involve translation, rotation, and removal of obstacles. Our model learns highly transferable features between robotic workspaces, requiring little to no fine-tuning to adapt to new transformations of obstacles in the workspace.Comment: 6 pages, 7 figures, 4 table