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Russellville, AR, United States

Arkansas Tech University is a comprehensive regional institution located in Russellville, Arkansas, United States. The university offers programs at both baccalaureate and graduate levels in a range of fields. Arkansas Tech will welcome its first doctoral cohorts in the Summer of 2015. The Arkansas Tech University–Ozark Campus, a two-year satellite campus in the town of Ozark, primarily focuses on associate and certificate education. Wikipedia.

Samson J.E.,Arkansas Tech University | Tanner-Smith E.E.,Vanderbilt University
Journal of Studies on Alcohol and Drugs | Year: 2015

Objective: The purpose of this study was to conduct a meta-analysis summarizing the effectiveness of brief, single-session interventions to reduce alcohol use among heavy drinking college students. Method: A comprehensive literature search identified 73 studies comparing the effects of single-session brief alcohol intervention with treatment-as-usual or no-treatment control conditions on alcohol use among heavy drinking college students. Random-effects meta-analyses with robust variance estimates were used to synthesize 662 effect sizes, estimating the average overall effect of the interventions and the variability in effects across a range of moderators. Results: An overall mean effect size of g = 0.18, 95% CI [0.12, 0.24] indicated that, on average, single-session brief alcohol interventions significantly reduced alcohol use among heavy drinking college students relative to comparison conditions. There was minimal variability in effects associated with study method and quality, general study characteristics, participant demographics, or outcome measure type. However, studies using motivational enhancement therapy/motivational interviewing (MET/MI) modalities reported larger effects than those using psychoeducational therapy (PET) interventions. Further investigation revealed that studies using MET/MI and feedback-only interventions, but not those using cognitive–behavioral therapy or PET modalities, reported average effect sizes that differed significantly from zero. There was also evidence that long-term effects were weaker than short-term effects. Conclusions: Single-session brief alcohol interventions show modest effects for reducing alcohol consumption among heavy drinking college students and may be particularly effective when they incorporate MET/MI principles. More research is needed to directly compare intervention modalities, to develop more potent interventions, and to explore the persistence of long-term effects. © 2015, Alcohol Research Documentation Inc. All rights reserved. Source

Chen X.,Arkansas Tech University | Kwan M.-P.,University of Illinois at Urbana - Champaign
American Journal of Public Health | Year: 2015

We examined the uncertainty of the contextual influenceson foodaccess through an analytic framework of the uncertain geographic context problem (UGCoP). We first examined the compounding effects of two kinds of spatiotemporal uncertainties on people's everyday efforts to procure food and then outlined three key dimensions (food access in real time, temporality of the food environment, and perceived nutrition environment) in which research on food access must improve to better represent the contributing environmental influences that operate at the individual level. Guidelines to address the UGCoP in future food access research are provided to account for the multidimensional influences of the food environmentondietarybehaviors. Source

Mebi C.A.,Arkansas Tech University
Journal of Chemical Sciences | Year: 2011

Three cis-isomers of [(NC5H4-S)2Fe(CO) 2], models for the active site of [Fe] hydrogenase, have been examined by computational method at DFT B3LYP/6-311+G(d,p) level. The computed geometric parameters are remarkably close to experimental values. DFT global chemical reactivity descriptors (chemical hardness, total energy, electronic chemical potential, and electrophilicity) are calculated for the isomers and used to predict their relative stability and reactivity. The chemical reactivity indices are found to be related to the bond angle defined by the cis carbonyls and the iron center. © Indian Academy of Sciences. Source

Hardcastle F.D.,Arkansas Tech University | Hardcastle F.D.,University of Arkansas at Little Rock | Ishihara H.,University of Arkansas at Little Rock | Sharma R.,Arkansas State University | Biris A.S.,University of Arkansas at Little Rock
Journal of Materials Chemistry | Year: 2011

The photoelectrochemical (PEC) activity of untreated (not anodized) and anodized nanotubular TiO2 films (synthesized by the electrochemical anodization of Ti foil) was correlated with the phase composition of the film as a function of O2-annealing temperature at 400, 500 and 600 °C. TiO2 nanotubes have been shown to be more efficient than polycrystalline TiO2 for the photocatalytic splitting of water. Raman spectroscopy was used to identify the amorphous and crystalline TiO2 phases as well as the carbon species. The amorphous TiO2 nanotubular array (unheated) exhibits a Raman spectrum consistent with TiO6 8- octahedra having the same average structure as those present in the anatase and rutile phases of TiO2. Ratios of integrated Raman peaks were used as a semi-quantitative measure of the degree of crystallinity for rutile and the rutile/anatase weight ratio in the films. Results show that the anatase-to-rutile transformation on Ti metal initiates at much lower temperatures compared to polycrystalline TiO2 and this is attributed to oxygen vacancies located at the metal/oxide interface. For untreated films, the amorphous TiO2 crystallizes directly to rutile, and the photocurrent density increases almost linearly with rutile crystallinity as the O2-annealing temperature is increased; anatase does not form on untreated O2-annealed Ti foil. By comparison, amorphous TiO 2 nanotubular arrays are converted to about three times as much anatase as rutile at 400 °C, where the photocurrent density is only slightly greater than the corresponding untreated film. At 500 °C, however, the photocurrent density increases to 2.3× that of the untreated-oxidized film, where ∼83% of the TiO2 nanotubular film is rutile and ∼17% is anatase; this enhancement is attributed to the increase in surface area and photoactive sites of the rutile provided by the TiO2 nanotubular array architecture acting as a support. At 600 °C the rutile transformation continues (∼92% rutile), but this is countered by the significant loss of surface area and surface photoactive sites due to degradation and collapse of the nanotubular structure as seen by SEM. © 2011 The Royal Society of Chemistry. Source

Chen Z.,Arkansas Tech University | Wu L.,Clarkson University | Shahidehpour M.,Illinois Institute of Technology
IEEE Transactions on Sustainable Energy | Year: 2015

This paper evaluates the effective load carrying capability (ELCC) of renewable resources, including wind and solar, via the stochastic long-term hourly based security-constrained unit commitment (SCUC) model. Different from traditional approaches which approximate ELCC of renewable resources using system peak loads, nonsequential block load duration curves, or rolling-based sequential methods, the stochastic long-term hourly based SCUC could accurately examine the impacts of short-term variability and uncertainty of renewable resources as well as chronological operation details of generators on hourly supplydemand imbalance and power system reliability in a long-term horizon. Uncertainties of hourly wind, solar, and load in a 1-year horizon are simulated via the scenario tree using the Monte Carlo method, and Approximate Dynamic Programming is adopted for effectively solving the stochastic long-term hourly based SCUC model. Variability correlations between wind speed and solar radiation are considered within the scenario sampling procedure. Moreover, parallel computing is designed with the pipeline structure for accelerating the computational performance of Approximate Dynamic Programming. Numerical case studies on the modified IEEE 118-bus system illustrate the effectiveness of the proposed stochastic long-term hourly based SCUC model and the Approximate Dynamic Programming solution approach for evaluating ELCC of renewable resources. This would help independent system operators (ISO) designs effective long-term planning strategies for operating power systems efficiently and reliably. © 2010-2012 IEEE. Source

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