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This paper describes a mixed flow reactor experiment and associated data analysis scheme that are well suited for studying the chemical and physical processes that occur in limestone drains used to treat acid mine drainage (AMD). The experiment simulates the slowly evolving, near steady state, reactions that form coatings on limestone. The resulting coatings can be recovered for analysis of their structure and composition. Analysis of the time evolution of the composition of the effluent solutions is used to isolate and understand key factors that affect limestone drain performance. The experiment investigated reactions between acidic aluminum sulfate solutions and calcite. The aluminum sulfate feed solutions contained 0.002-0.01 molal (32-329 mg/kg) Al and had pH values ranging from 3.7 to 4.2. At the beginning each experiment, the rate of H+ consumption by reaction with the calcite was fast causing a distinct increase of the effluent pH. The pH increase caused some of the dissolved Al to precipitate as a coating on the calcite surfaces. The coating blocked the transfer of ions to and from the calcite causing the reaction rates to be limited by ion diffusion through the coating. The continued growth of the coating caused it to become an increasingly effective barrier to ion transport, which caused the neutralization rate to slow and the effluent solution pH to decline toward that of the feed solution. Powder X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) suggested that the coatings were mostly poorly crystalline gibbsite. Effluent solutions were analyzed to determine pH along with Al, Ca and S concentrations. The coating thickness at each sample time was estimated from the amount of Al lost from the solution since the beginning of the experiment. This thickness and the Ca and H+ fluxes were used to find the apparent H+ diffusion coefficient in the coatings. ; Department of Geosciences at Virginia Tech; College of Science at Virginia Tech; Graduate School at Virginia Tech ; Palomino-Ore thanks the Fulbright program for the opportunity to study in the USA and the Department of Geosciences, the College of Science and the Graduate School at Virginia Tech for financial support. We thank F. Marc Michel for manufacturing the reactor used in this study. We thank Neil Johnson for help with the XRD, Qing Tang for help with the SEM, and Athena Tilley for ICP OES analyses. We greatly appreciate helpful reviews by Charles Cravotta, Kate Campbell, and Jane Hammarstrom. ; Public domain authored by a U.S. government employee

In Canada, the human papillomavirus (HPV) vaccine is licensed and recommended for females and males. Although all Canadian jurisdictions fund school-based HPV vaccine programs for girls, only six jurisdictions fund school-based HPV vaccination for boys. The research aimed to analyze the factors that underpin government decisions to fund HPV vaccine for boys using a theoretical policy model, Kingdon's Multiple Streams framework. This approach assesses policy development by examining three concurrent, but independent, streams that guide analysis: Problem Stream, Policy Stream, and Politics Stream. Analysis from the Problem Stream highlights that males are affected by HPV-related diseases and are involved in transmitting HPV infection to their sexual partners. Policy Stream analysis makes clear that while the inclusion of males in HPV vaccine programs is suitable, equitable, and acceptable; there is debate regarding cost-effectiveness. Politics Stream analysis identifies the perspectives of six different stakeholder groups and highlights the contribution of government officials at the provincial and territorial level. Kingdon's Multiple Streams framework helps clarify the opportunities and barriers for HPV vaccine policy change. This analysis identified that the interpretation of cost-effectiveness models and advocacy of stakeholders such as citizen-advocates and HPV-affected politicians have been particularly important in galvanizing policy change.

The principal purpose of this paper is to analyze different methods for decision making, with a focus on entrepreneurship in Latin America. Decision-making methods may be informed by aggregation operators that are based on the use of probabilities, weighted averages (WAs) and generalized aggregation operators. The paper presents a new generalized probabilistic weighted averaging (GPWA) operator that unifies WAs and probability in the same formulation, considering the degree of importance of each concept used in the analysis. The fundamental advantage of this approach is that it includes a wide range of particular cases including the probabilistic weighted averaging (PWA) operator, the probabilistic weighted geometric averaging (PWGA) operator and the probabilistic weighted quadratic averaging (PWQA) operator. Quasi-arithmetic means are used to obtain the Quasi-PWA operator and to generalize the approach, which is then applied to a set of hypothetical entrepreneurial investment decisions in a politically unified Latin American region. ; El objetivo principal de este artículo es analizar diferentes mé- todos de toma de decisiones, con enfoque en el emprendimiento en Latinoamérica. Los métodos de toma de decisiones pueden recibir información por parte de operadores de agregación basados en el uso de probabilidades, promedios ponderados (PP) y operadores de agregación generalizados. El artículo presenta un nuevo operador probabilístico generalizado de promedios ponderados (GPWA) que unifica los promedios ponderados y la probabilidad en la misma formulación, considerando el grado de importancia de cada concepto usado en el análisis. La ventaja fundamental de este enfoque es que incluye un amplio rango de casos particulares, incluyendo el operador probabilístico de promedios ponderados, el operador probabilístico de promedios geométricos ponderados y el operador probabilístico de promedios cuadráticos ponderados. Se emplean medios cuasiaritméticos para obtener el operador cuasiprobabilístico de promedios ponderados y ...

AbstractOur paper studies multilevel strategic R&D investment decisions. We distinguish between exogenous and endogenous knowledge transfers and focus the relationship between optimal market structure and technological progress. In general, R&D cooperation leads to high levels of R&D investment when firms are supposed to be symmetrical. However, the relaxation of the symmetry hypothesis, considering multiplayer models (innovators and free‐riders), contradicts previous findings. We show how absorptive capacity concepts explain the incentives and mechanisms of R&D investment. We attempt to answer, through our survey, to the central question: Should firms cooperate or compete in industrial markets?

This article has two aims. The first is to present results that partly explain why some automobile drivers choose to use their seatbelts only part time, thereby exposing themselves to unnecessary risk. The second is to offer and illustrate the "cardinal decision issue perspective"(1) as a tool for guiding research and development efforts that focus on complex real‐life decision behaviors that can entail wide varieties of risk, including but not limited to inconsistent seatbelt use. Each of 24 young male participants drove an instrumented vehicle equipped to record continuously seatbelt use as well as other driving data. After all trips were finished, each participant completed an interview designed to reconstruct how he made randomly selected seatbelt‐use decisions under specified conditions. The interview also examined whether and how drivers established "decision policies" regarding seatbelt use. Such policies were good predictors of inconsistent seatbelt use. Drivers who had previously adopted policies calling for consistent seatbelt use were significantly more likely than others to actually drive belted. Meta‐decisions about seatbelt policy adoption appeared to rest on factors such as whether the driver had ever been asked to consider selecting a policy. Whether a driver made an ad hoc, on‐the‐spot seatbelt‐use decision was associated with a perceived need to make such a decision. Finally, participants with full‐time policies were especially likely to deploy their seatbelts by default, without recognizing the need to decide about belt use on a trip‐by‐trip basis. We end with recommendations for reducing inconsistencies in seatbelt use in actual practice.