Use of W-Boson Longitudinal-Transverse Interference in Top Quark Spin-Correlation Functions: II

This continuation of the derivation of general beam-referenced stage-two spin-correlation functions is for the analysis of top-antitop pair-production at the Tevatron and at the Large Hadron Collider. Both the gluon-production and the quark-production contributions are included for the charged-lepton-plus-jets reaction p p or p bar{p} --> t bar{t} --> (W^+ b)(W^- bar{b}) --> (l^{+} nu b)(W^- bar{b}). There is a simple 4-angle beam-referenced spin-correlation function for determination of the relative sign of, or for measurement of a possible non-trivial phase between the two dominant helicity amplitudes for t --> W^{+} b decay. There is an analogous function and tests for bar{t} --> W^{-} bar{b} decay. This signature requires use of the (t bar{t}) c.m.-energy of the hadronically decaying W-boson, or the kinematically equivalent cosine of the polar-angle of W-boson emission in the anti-top (top) decay frame. Spinors and their outer-products are constructed so that the helicity-amplitude phase convention of Jacob & Wick can be used throughout for the fixing of the signs associated with this large W-boson longitudinal-transverse interference effect.Comment: Continuation of hep-ph/0506240 to include gluon-production contribution; 3 "postscript" figures. Equation numbers as in published-on-line EPJ

Ways Forward in Energy Markets and the Environment

Renewable energy sources have come to the forefront of energy production policy over the last twenty years. Studies of external and direct costs of both renewable and nonrenewable energy sources have contributed to growing understandings of ways in which these energy sources can be compared in a monetary context. Using data from the U.S. Energy Information Administration (EIA) alongside international data from the International Renewable Energy Agency (IRENA) among other sources, we have developed forecasts for the future costs, both direct and social, of each energy source as well as a difference-in-difference experiment to determine potential effects of state-level energy policy changes on state level energy prices. Forecasting is generally reliable as long as no major shocks to the variables in question present themselves during the period being forecast. This paper finds that renewable energy’s social and direct costs are both forecasted to be lower than nonrenewable energy’s cost even while considering renewable energy’s higher up-front costs. Additionally, statewide energy policy appears to have no significant effect on renewable energy prices in the three years following adoption, so further research with larger datasets is recommended

A Case Study of a Mature Appalachian HIV Negative Homosexual Man on HIV Positive Homosexual Men

Because of the lack of study, little is known about how members of the gay community immersed in rural areas relate to one another especially relative to the AIDS Crisis and those gay men living with HIV (Eldridge, Mack, & Swank, 2008). The purpose of this study was to investigate features of attitude (fears, threats, preconceived notions, and convictions) of a mature HIV negative homosexual man from rural Appalachia on HIV positive homosexual men (Thurstone, 1928). The central research question asked was, “How do you relate to HIV positive gay men as a HIV negative gay man having been raised in rural Appalachia and lived through the AIDS Crisis?” The criteria for selecting a subject for this study was an HIV negative homosexual male, 52-60 years of age, and being raised from birth in rural Appalachia. This thesis was a case study of one subject through a series of four interviews elucidating attitudes on psychological, social, and health implication of the subject’s interactions with people living with HIV (Halkitis, Wolitski, and Millet, 2013). The researcher transcribed these with general results narrowed into specific conclusions by identifying each time the subject re-counted an experience having to do with a gay HIV positive man. Three significant conclusions were drawn: The subject held (a) accepting, (b) concerned, and (c) empathetic attitudes toward gay men living with HIV

Postharvest Degradation of Microalgae: Effect of Temperature and Water Activity

Though usually a nuisance in swimming pools and ponds, algae has the potential to be a valuable commodity for use as food and fuel. But before algae butter and biofuel become commonplace, issues with harvesting and storing this new crop need to be overcome. Though there has been ample research into how to grow and use algae, scientists have spent little time figuring out what to do after you pull it out of the water and before you eat it (or turn it into biodiesel). Algae, like all food products, starts to spoil as soon as it is harvested. This study looked at three methods of preserving algae, freezing, drying, and pasteurization. Freezing is a good method for preserving fats and proteins, but it is expensive to freeze tons of algae. Freezing and thawing destroyed the algal cells, producing a soupy mixture that may cause complications for processing into foods or fuels. Drying was able to preserve the fats in algae, but only if it was dried just the right amount, about as dry as cheese or ham. Pasteurization was able to prevent the oils in the algae from going rancid by inactivating a protein in the algae that causes the oil to spoil rapidly. Overall, this research is an initial step in finding a process to produce a shelf stable algal commodity, opening the door to new and valuable products for human use

The impact of functional modeling on engineering students\u27 mental models

The ability to understand complexity and think holistically about systems is an increasingly important part of engineering design. This is embodied in the concept of systems thinking, a concept studied primarily in the fields of systems dynamics and systems engineering. Systems thinking ability is built off mental models, a loosely-defined construct people form to make predictions about their surroundings. Methods to evaluate systems thinking and underlying mental models rely primarily on self-evaluative methods such as questionnaires, or detailed simulations of systems or processes; however these methods fail to directly capture students’ design tendencies. This work presents a visual instrument used to elicit and evaluate students’ mental models of two simple systems, a hair dryer and a car radiator. This instrument is used to evaluate the changes in students’ mental models after learning functional modeling, a systems abstraction method utilized in several engineering disciplines including engineering design. Two phases of analysis are presented. In the first phase of analysis, it is established that students had a significantly better understanding of the hair dryer than the car radiator system, based on the number of critical components students included in their responses; in this first phase, a component-based scoring strategy is presented. The second phase of analysis presents a scoring method based on Module Heuristics, a method for decomposing and categorizing flows and groups of functions within a functional model of a system. Module Heuristics are used to show the analogous functional flows between the hair dryer and car radiator. The scoring method is then used to investigate changes in students’ mental models resulting from learning functional modeling

Ecosystem ranspiration from eddy covariance

Transpiration is an integral part of the earth system, not only because plant water use is the dominant path by which water flows from the soil to the atmosphere, but also because water loss from leaves is intrinsically connected to CO2 uptake and provides a key link between global carbon and water cycles. Transpiration, while well studied at the scale of plants and leaves, remains difficult to quantify at the ecosystem, regional, and global scales. Differentiating between water vapor which has passed through plants, and is thus biologically controlled, and water vapor which is evaporated from surfaces without active control from plants through stomatal regulation is extremely challenging at the ecosystem scale with heterogeneous landscapes containing diverse plant species accessing soil water reserves at varying depths. One potential solution to characterizing transpiration on broader scales is to use eddy covariance to estimate ecosystem transpiration. Eddy covariance has been widely utilized to measure water, carbon, and energy fluxes, with synthesis initiative such as FLUXNET collating hundreds of sites around the world. However, methods for partitioning the total ecosystem water flux (evapotranspiration, ET) measured by eddy covariance systems into the individual components, i.e. transpiration (T) and abiotic evaporation (E), are needed. The work presented here demonstrates the viability and utility of ecosystem scale estimates of transpiration from eddy covariance datasets via data driven methodologies. Identifying key strengths and uncertainties in the method, such as the uncertainty in the magnitude of transpiration but strength in spatial and temporal patterns, better outlines future directions

The Enduring Popularity of Legacy Journalism: An Analysis of Online Audience Data

As news publishers continue to lose subscribers and advertising revenue, journalism practitioners and researchers have looked to newcomers to the field for ideas of how to adapt and succeed in a much more saturated and unstable media environment. Many have specifically looked to digital native news organizations to understand the ways that journalism is attempting to reinvent itself for a media landscape that is very different from the previous one. Yet what often gets lost in this focus on the newest news organizations is the resilience of many of journalism’s older ones. In this study, I analyze a year’s worth of U.S.-based online news consumption data to show that, even in a media environment increasingly saturated with digital native news outlets, legacy news brands continue to comprise a majority of the most popular news sites. Drawing on audience studies literature, I argue that these findings likely reflect audience preferences for familiar, established brands, as well as structural advantages these brands maintain due to their size and capital. I conclude that the fate of digital news organizations is not just a question of their innovativeness or nimbleness. It is also a question of their ability to combat a combination of powerful, stubborn forces: the habits of the people they hope to reach, and the deep pockets of their competitors