MIGRATION PATTERNS AMONG YOUNG ADULTS IN THE UNITED STATES: ENVIRONMENTAL, SOCIAL, AND ECONOMIC EXPLANATIONS

Young adult migration is a key factor in community development. The goal of this paper is to study what kinds of places attract young adults and what kinds are losing them. Linear regression is conducted to analyze what place-specific factors explain migration patterns among young adults. These factors include economic, social, and environmental variables. This study finds that social and environmental factors are just as important as economic ones. Specifically, employment in the arts increases young adult net migration. Environmental variables, for example, natural amenities and protected federal lands are particularly important in rural settings in attracting young adults. These findings suggest that policy makers interested in attracting and retaining young adults should pay closer attention to social and environmental factors and consider creating more opportunities for arts employment in general. For rural areas, improving the attractiveness of natural amenities and better protection of federal lands is also recommended

Public preferences of the Great Lakes Environment : a Lake Michigan pilot study

The Great Lakes watershed is home to over 40 million people, and the health of the Great Lakes ecosystem is vital to the overall economic, societal, and environmental health of the U.S. and Canada. However, environmental issues related to them are sometimes overlooked. Policymakers and the public face the challenges of balancing economic benefits with the need to conserve and/or replenish regional natural resources to ensure long term prosperity. From the literature review, nine critical stressors of ecological services were delineated, which include pollution and contamination, agricultural erosion, non-native species, degraded recreational resources, loss of wetlands habitat, climate change, risk of clean water shortage, vanishing sand dunes, and population overcrowding; this list was validated through a series of stakeholder discussions and focus groups in Grand Rapids. Focus groups were conducted in Grand Rapids to examine the awareness of, concern with, and willingness to expend resources on these stressors. Stressors that the respondents have direct contact with tend to be the most important. The focus group results show that concern related to pollution and contamination is much higher than for any of the other stressors. Low responses to climate change result in recommendations for outreach programs

A novel transcritical CO2 refrigeration cycle with two ejectors

In recent years, CO2 is being revisited as a fully environmentally friendly and safe refrigerant. However, basic CO2 transcritical refrigeration cycle suffers from large expansion loss due to high pressure difference between gas cooler and evaporator. Then, it is crucial to find effective and economic way to reduce the expansion loss. Here, a novel cycle with two ejectors is proposed for the first time. Compared with conventional ejector-expansion CO2 cycle with only one ejector, this novel cycle with two ejectors is able to recover more expansion loss, thus improving the system performance further. A computational model is designed to simulate the double ejector CO2 cycle. Simulation results show its high system COP. Effects of parameters, such as ejector nozzle efficiency, gas cooler pressure, entrainment ratios of the two ejectors, gas cooler outlet temperature, on the cycle performance are also analyzed by using the computational model. (C) 2012 Elsevier Ltd and IIR. All rights reserved.</p

Detection Schemes for Multi-Antenna FH/MFSK Systems in the Presence of Multiple Follower Jamming

Ph.DDOCTOR OF PHILOSOPH

Numerical study of vapor bubble effect on flow and heat transfer in microchannel

Flow boiling in a microchannel is characterized by nucleation and dynamic behavior of vapor bubbles in the channel. In the present study, the effect of vapor bubble on fluid flow and heat transfer in a microchannel is investigated via lattice Boltzmann (LB) modeling. With respect to boiling flow in a single microchannel, the bubble nucleation, growth, and departure are simulated by using an improved hybrid LB model. Relating bubble behavior with fluid flow and boiling heat transfer provides some insight into the relevant fundamental physics on flow boiling in the microchannel. It is found that the bubble growth before its departure from the wall induces an obvious resistance to the fluid flow. The processes of nucleation and motion of different bubbles interact, leading to an alternate, either enhanced or weakened, effect of bubble behavior on the flow boiling. (C) 2011 Elsevier Masson SAS. All rights reserved.</p