Numerical investigation of the flow profiles in the electrically enhanced cyclone

A numerical model for simulation of the electrohydrodynamic flow in an electrically enhanced cyclone is presented. A finite element approach was applied to solve the coupled equations for the positive corona-induced electric field. Three-dimensional simulations of gas flow were carried using Reynolds-Averaged Navier-Stokes equations including the Reynolds stress model and the electrohydrodynamic effect. Numerical results show that the change in the flow profile because of the influence of the corona-induced electric field is apparent when the inlet flow rate is low but is negligible at higher flow rates.     

Nation,demographic, and attitudinal boundary conditions on leader social rewards and punishments in local governments

Boundary conditions on the relationships of contingent rewards and noncontingent punishments with evaluated performance and satisfaction are sought for supervisory and professional staff in local governments in the United States and Japan. Subgroup differences in tolerance for noncontingent punishment are reflected in mean differences in its use between nations (more reported in Japan), genders (less reported by women), and regions of the United States. The effects of noncontingent punishment on outcomes were not found for U.S. police sergeants. Evidence for a national contingency is reflected in the finding that the relationship of noncontingent punishments (but not contingent rewards) with cooperation, individual effectiveness, and satisfaction was stronger in the United States than in Japan. The study adds caution to the culture‐free and contingency‐free application of the theory of performance‐contingent rewards and punishments. Implications for the theory of social rewards and punishments and for the contingencies and criteria considered in leadership research, particularly cross‐cultural leadership research, are addressed. Copyright © 2007 John Wiley & Sons, Ltd.     

Estimating the effectiveness of ergonomics interventions through case studies: implications for predictive cost-benefit analysis

PROBLEM: Cost-benefit analysis (CBA) can help to justify an investment in ergonomics interventions. A predictive CBA model would allow practitioners to present a cost justification to management during the planning stages, but such a model requires reliable estimates of the benefits of ergonomics interventions. METHOD: Through literature reviews and Internet searches, 250 case studies that reported the benefits of ergonomics programs and control measures were collected and summarized. RESULTS: Commonly reported benefits included reductions in the number of work-related musculoskeletal disorders (WMSDs) or their incidence rate, as well as related lost workdays, restricted workdays, and workers' compensation costs. Additional benefits reported were related to productivity, quality, turnover and absenteeism. DISCUSSION: Benefits reported were largely positive, and payback periods for ergonomics interventions were typically less than one year. SUMMARY: The results of this review could be used to develop predictive CBA models for ergonomics programs and individual control measures. IMPACT ON INDUSTRY: Cost-justifying ergonomics interventions prior to implementation may help to secure management support for proposed changes. Numbers used for the benefits side of a cost-benefit analysis (CBA) need to be based on "real world" data in order to be credible. The data presented in this paper may help in the development of simple cost-benefit models for ergonomics programs and control measures.     

Conservation Without Borders: Building Communication and Action Across Disciplinary Boundaries for Effective Conservation

Interdisciplinary approaches to conservation research and environmental management continue to garner interest among practitioners, academics, and students. Yet, cases of practitioners and researchers from different disciplines successfully working in concert towards an integrated conservation approach are rare. What is preventing practitioners of multiple disciplines from harmoniously working together? Why are practitioners and academics struggling to apply their graduate training to real world conservation? What is preventing the benefits of cooperation and partnerships between different disciplines addressing conservation from being realized? This special issue “Conservation without Borders: Building Communication and Action across Disciplinary Boundaries for Effective Conservation” asks readers to consider the numerous interpretations and implications of the phrase “Conservation without Borders” and to reflect on how different academic and disciplinary lenses can contribute to a more integrated approach to tackling conservation challenges. The articles that comprise this special issue offer readers insights into the ways in which different disciplines view conservation work and interdisciplinary approaches to environmental problems. Bringing these perspectives and approaches together in one place is a step towards improving communication across disciplines for the purpose of achieving more successful biodiversity conservation.     

Changes in weather and climate extremes: State of knowledge relevant to air and water quality in the United States

Air and water quality are impacted by extreme weather and climate events on time scales ranging from minutes to many months. This review paper discusses the state of knowledge of how and why extreme events are changing and are projected to change in the future. These events include heat waves, cold waves, floods, droughts, hurricanes, strong extratropical cyclones such as nor'easters, heavy rain, and major snowfalls. Some of these events, such as heat waves, are projected to increase, while others, with cold waves being a good example, will decrease in intensity in our warming world. Each extreme's impact on air or water quality can be complex and can even vary over the course of the event.

Implications:

Because extreme weather and climate events impact air and water quality, understanding how the various extremes are changing and are projected to change in the future has ramifications on air and water quality management.     

Modeling alkene chemistry using condensed mechanisms for conditions relevant to southeast Texas,USA

Alkenes are important in photochemical smog formation in southeast Texas due to their high emissions, especially from industrial sources in and around Houston, and their high reactivities. Therefore, properly characterizing the chemistry of alkenes in condensed mechanisms used in regional photochemical models is important in understanding the formation of ozone and other photochemical air pollutants in Houston. The performance of three versions of the SAPRC condensed chemical mechanism family, for predicting ozone and radical formation, was compared. Simulations were compared to environmental chamber data and ambient data. The analyses showed that separately modeling individual alkenes reactions (especially propene for southeast Texas) has the potential to lead to more accurate simulations of alkene chemistry. Caution must be exercised in un-lumping, however. Testing with different formulations of the 1-butene + O₃ reaction demonstrated the complexity and interconnectedness in choices of stoichiometric parameters for un-lumped species and the extent to which lumped mechanisms are un-lumped.     

Effects of urbanization on the population structure of freshwater turtles across the United States

Landscape‐scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands‐on experience in conservation science.     

Advancing “Autonomous” sensing and prediction of the subsurface environment: a review and exploration of the challenges for soil and groundwater contamination

Environmental Science and Pollution Research - Can we hope for autonomous (self-contained in situ) sensing of subsurface soil and groundwater pollutants to satisfy relevant regulatory criteria?...     

Assumption‐versus data‐based approaches to summarizing species’ ranges

For conservation decision making, species’ geographic distributions are mapped using various approaches. Some such efforts have downscaled versions of coarse‐resolution extent‐of‐occurrence maps to fine resolutions for conservation planning. We examined the quality of the extent‐of‐occurrence maps as range summaries and the utility of refining those maps into fine‐resolution distributional hypotheses. Extent‐of‐occurrence maps tend to be overly simple, omit many known and well‐documented populations, and likely frequently include many areas not holding populations. Refinement steps involve typological assumptions about habitat preferences and elevational ranges of species, which can introduce substantial error in estimates of species’ true areas of distribution. However, no model‐evaluation steps are taken to assess the predictive ability of these models, so model inaccuracies are not noticed. Whereas range summaries derived by these methods may be useful in coarse‐grained, global‐extent studies, their continued use in on‐the‐ground conservation applications at fine spatial resolutions is not advisable in light of reliance on assumptions, lack of real spatial resolution, and lack of testing. In contrast, data‐driven techniques that integrate primary data on biodiversity occurrence with remotely sensed data that summarize environmental dimensions (i.e., ecological niche modeling or species distribution modeling) offer data‐driven solutions based on a minimum of assumptions that can be evaluated and validated quantitatively to offer a well‐founded, widely accepted method for summarizing species’ distributional patterns for conservation applications.