University of Texas at Arlington

About: University of Texas at Arlington is a education organization based out in Arlington, Texas, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 11758 authors who have published 28598 publications receiving 801626 citations. The organization is also known as: UT Arlington & University of Texas-Arlington.

Measurement of inclusive jet and dijet production in pp collisions at root s=7 TeV using the ATLAS detector

Abstract: Inclusive jet and dijet cross sections have been measured in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector at the Large Hadron Collider. The cross sections were measured using jets clustered with the anti-kT algorithm with parameters R=0.4 and R=0.6. These measurements are based on the 2010 data sample, consisting of a total integrated luminosity of 37 inverse picobarns. Inclusive jet double-differential cross sections are presented as a function of jet transverse momentum, in bins of jet rapidity. Dijet double-differential cross sections are studied as a function of the dijet invariant mass, in bins of half the rapidity separation of the two leading jets. The measurements are performed in the jet rapidity range |y|<4.4, covering jet transverse momenta from 20 GeV to 1.5 TeV and dijet invariant masses from 70 GeV to 5 TeV. The data are compared to expectations based on next-to-leading order QCD calculations corrected for non-perturbative effects, as well as to next-to-leading order Monte Carlo predictions. In addition to a test of the theory in a new kinematic regime, the data also provide sensitivity to parton distribution functions in a region where they are currently not well-constrained.

Dumb and Dumber: The Impact of Downsizing on Firm Performance as Moderated by Industry Conditions

Abstract: Workforce downsizing through employee layoffs has become commonplace in American businesses over the last 20 years. While these initiatives are typically undertaken in the quest for improved firm performance and competitiveness, empirical research to date has been equivocal in supporting the efficacy of these initiatives. In addition, extant research has not thoroughly examined factors or conditions that may influence or moderate the performance impact of workforce downsizing. In this paper, we address the question: Do industry conditions moderate the impact of workforce downsizing on firm performance? We examine this question using matched primary and secondary data on a sample of U.S. manufacturing firms. After controlling for a set of industry and firm-level variables, including firms' prior performance levels, our results indicate that downsizing is associated with decreases in subsequent firm profitability and that these negative effects are more pronounced in industries characterized by research and development (R&D) intensity, growth, and low capital intensity.

System impact study for the interconnection of wind generation and utility system

Abstract: Following in the steps of the gas industry, the traditional paradigm of the vertically integrated electric utility structure has begun to change. In the United States, the Federal Energy Regulatory Commission (FERC) has issued several rules and Notices of Proposed Rulemaking (NOPR) to set the road map for the deregulated utility industry. The crisis in California has drawn great attention and sparked intense discussion within the utility industry. One general conclusion is to rejuvenate the idea of integrated resource planning and promote the distributed generation via traditional or renewable generation facilities for the deregulated utility systems. Wind generation is the most mature and cost effective resource among different renewable energy technologies. Recently, several large-scale wind generation projects have been implemented in the US and other parts of the world. Similar to other new generation facilities, the impacts of a large scale wind generation on the system operation, voltage profile, and system security have to be investigated and studied. Remedies for possible operation issues have to be evaluated and implemented. This paper discusses the impact study of connecting a 120 MW wind farm into the transmission system of a utility company within the Southwest Power Pool (SPP).

Microbial mats in terrigenous clastics; the challenge of identification in the rock record

Abstract: Increasingly, microbial communities are recognized for playing a potentially important role in defining and modifying surface sediment characteristics in various settings, ranging from terrestrial, through marginal marine, to continental margins. Whereas, the presence of microbial mats can be established with comparative ease in modern terrigenous clastics, their recognition in sedimentary rocks poses a big challenge. Terrigenous clastics of the Belt Supergroup (Mid-Proterozoic) show a number of features that can serve as microbial mat indicators: (A) domal buildups; (B) cohesive behavior; (C) wavy-crinkly character of laminae; (D) irregular wrinkled bed surfaces; (E) ripple patches; (F) laminae with mica enrichment; (G) irregular, curved-wrinkled impressions on bedding planes; and (H) lamina-specific distribution of early diagenetic minerals (dolomite, ferroan carbonate, pyrite). Positive identification of a fossil microbial mat requires one to find microbial filaments in life position. This is a difficult task even in the case of very favorable preservation of organic matter, and impossible to accomplish in many instances where fossil microbial mats are suspected. Nonetheless, the above features (especially when found in combination) are highly suggestive of microbial mats, and can serve as guides to sediments that may have accumulated under the influence of microbial mats. Whereas the Belt Basin examples are all from shallow-water environments, microbial mats may also have played an important role in deeper-water oxygen-deprived settings-the realm of black shale formation. In areas of modern oxygen-minimum zones, microbial mats have been found to thrive at the seafloor, profoundly influencing the chemistry of the sediment/water interface and sediment stability. Possible ancient analogs occur in a variety of black shale deposits (e.g. Jet Rock, Monterey Formation, Green River Formation), with wavy to crinkly kerogen-rich laminae being the main indication of possible microbial mat origins. Although microbial mats clearly have the ability to thrive in black shale environments, it will require more research to firmly establish whether, and how extensively, they occupied this niche in the geologic past.