Lamar University

Advanced oxidation processes (AOPs) were first proposed in the 1980s for drinking water treatment and later were widely studied for treatment of different wastewaters. During the AOP treatment of wastewater, hydroxyl radicals (OH·) or sulfate radicals (SO4 ·−) are generated in sufficient quantity to remove refractory organic matters, traceable organic contaminants, or certain inorganic pollutants, or to increase wastewater biodegradability as a pre-treatment prior to an ensuing biological treatment. In this paper, we review the fundamental mechanisms of radical generation in different AOPs and select landfill leachate and biologically treated municipal wastewater as model wastewaters to discuss wastewater treatment with different AOPs. Generally, the treatment efficiencies rely heavily upon the selected AOP type, physical and chemical properties of target pollutants, and operating conditions. It would be noted that other mechanisms, besides hydroxyl radical or sulfate radical-based oxidation, may occur during the AOP treatment and contribute to the reduction of target pollutants. Particularly, we summarize recent advances in the AOP treatment of landfill leachate, as well as advanced oxidation of effluent organic matters (EfOM) in biologically treated secondary effluent (BTSE) for water reuse.

Nine studies were conducted with the goal of developing a self-report measure of psychological entitlement and assessing its interpersonal consequences. The Psychological Entitlement Scale (PES) was found to be reliable and valid (Study 1, 2), not associated with social desirability (Study 2), stable across time (Study 3), and correlated negatively with two of the Big Five factors: agreeableness and emotional stability (Study 4). The validity of the PES was confirmed in studies that assessed willingness to take candy designated for children (Study 5) and reported deservingness of pay in a hypothetical employment setting (Study 6). Finally, the PES was linked to important interpersonal consequences including competitive choices in a commons dilemma (Study 7), selfish approaches to romantic relationships (Study 8), and aggression following ego threat (Study 9). Psychological entitlement has a pervasive and largely unconstructive impact on social behavior.

Abstract New computer-based communications technologies make possible new or expanded forms of group work. Although earlier researchers suggest that scant social information in these technologies might cause status equalization in groups, no experimental test of this phenomenon has been made. In a laboratory experiment, we compared face-to-face communication with electronic mail in decision-making groups whose members differed in social status. We examined status in two ways: by varying the external status of group members, and by varying the decision task to manipulate expertise. When the groups made decisions in face-to-face meetings, the high-status member dominated discussions with the three low-status members. Also, the high-status member more often was a "first advocate" in the face-to-face discussions, and first advocates were more influential than later advocates. These status inequalities in face-to-face decision making were pronounced just when the high-status member's expertise was relevant to the decision task. When the same groups made comparable decisions using electronic mail, status and expertise inequalities in participation were reduced. A striking and unexpected result was that "first" advocacy was shared by high- and low-status members in discussions using electronic mail. This behavior resulted in increased equality of influence across status and expertise. We discuss the implications of these results for research and for design of new communication technologies.

Abstract This paper complements a recent study by Ramos‐Rodriguez and Ruiz‐Navarro (2004) that investigated the intellectual structure of the strategic management field through co‐citation analysis. By using authors as the units of analysis and incorporating all the citations that are included in the Science Citation Index and the Social Science Citation Index, we trace the evolution of the intellectual structure of the strategic management field during the period 1980–2000. Using a variety of data analytic techniques such as multidimensional scaling, factor analysis, and Pathfinder analysis, we (1) delineate the subfields that constitute the intellectual structure of strategic management; (2) determine the relationships between the subfields; (3) identify authors who play a pivotal role in bridging two or more conceptual domains of research; and (4) graphically map the intellectual structure in two‐dimensional space in order to visualize spatial distances between intellectual themes. The analysis provides insights about the influence of individual authors as well as changes in their influence over time. Copyright © 2007 John Wiley & Sons, Ltd.

The beam-energy scan at RHIC aims to discover whether a critical point exists in the phase diagram of QCD. This paper reports on the most comprehensive measurement of single-particle spectra for a multitude of hadrons from the first run, taken with the STAR experiment. From these the authors infer the kinetic and chemical freeze-out temperatures and the baryon chemical potential as functions of beam energy and centrality. The results provide an opportunity for the beam-energy scan program at RHIC to enlarge the ($T,\ensuremath{\mu}\phantom{\rule{0}{0ex}}B$) region of the phase diagram to search for the QCD critical point.

Gaseous elemental mercury (Hg0) is a globally distributed air toxin with a long atmospheric residence time. Any process that reduces its atmospheric lifetime increases its potential accumulation in the biosphere. Our data from Barrow, AK, at 71 degrees N show that rapid, photochemically driven oxidation of boundary-layer Hg0 after polar sunrise, probably by reactive halogens, creates a rapidly depositing species of oxidized gaseous mercury in the remote Arctic troposphere at concentrations in excess of 900 pg m(-3). This mercury accumulates in the snowpack during polar spring at an accelerated rate in a form that is bioavailable to bacteria and is released with snowmelt during the summer emergence of the Arctic ecosystem. Evidence suggests that this is a recent phenomenon that may be occurring throughout the earth's polar regions.

The line energy associated with the triple phase contact line is a function of local surface defects (chemical and topographical); however, it can still be calculated from the advancing and receding contact angles to which those defects give rise. In this study an expression for the line energy associated with the triple phase contact line is developed. The expression relates the line energy to the drop volume, the interfacial energies, and the actual contact angle (be it advancing, receding, or in between). From the expression we can back calculate the equilibrium Young contact angle, theta0, as a function of the maximal advancing, thetaA, and minimal receding, thetaR, contact angles. To keep a certain maximal hysteresis between advancing and receding angles, different line energies are required depending on the three interfacial energies and the drop's volume V. We learn from the obtained expressions that the hysteresis is determined by some dimensionless parameter, K, which is some normalized line energy. The value of K required to keep a constant hysteresis (thetaA-thetaR) rises to infinity as we get closer to theta0 = 90 degrees.

A facile thermodecomposition process to synthesize magnetic graphene nanocomposites (MGNCs) is reported. High-resolution transmission electron microscopy and energy filtered elemental mapping revealed a core@double-shell structure of the nanoparticles with crystalline iron as the core, iron oxide as the inner shell and amorphous Si-S-O compound as the outer shell. The MGNCs demonstrate an extremely fast Cr(VI) removal from the wastewater with a high removal efficiency and with an almost complete removal of Cr(VI) within 5 min. The adsorption kinetics follows the pseudo-second-order model and the novel MGNC adsorbent exhibits better Cr(VI) removal efficiency in solutions with low pH. The large saturation magnetization (96.3 emu/g) of the synthesized nanoparticles allows fast separation of the MGNCs from liquid suspension. By using a permanent magnet, the recycling process of both the MGNC adsorbents and the adsorbed Cr(VI) is more energetically and economically sustainable. The significantly reduced treatment time required to remove the Cr(VI) and the applicability in treating the solutions with low pH make MGNCs promising for the efficient removal of heavy metals from the wastewater.

In this review paper, the state-of-the-art knowledge of the core-shell multifunctional nanoparticles (MNPs), especially with unique physiochemical properties, is presented. The synthesis methods were summarized from the aspects of both the advantages and the demerits. The core includes the inexpensive and easily oxidized metals and the noble shells include the relatively noble metals, carbon, silica, other oxides, and polymers. The properties including magnetic, optical, anti-corrosion and the surface chemistry of the NPs are thoroughly reviewed. The current status of the applications is reviewed with the detailed examples including the catalysis, giant magnetoresistance (GMR) sensing, electromagnetic interface shielding or microwave absorption, biomedical drug delivery, and the environmental remediation.

Abstract A structural model incorporating agile manufacturing as the focal construct is theorized and tested. The model includes the primary components of JIT (JIT‐purchasing and JIT‐production) as antecedents and operational performance and firm performance as consequences to agile manufacturing. Using data collected from production and operations managers working for large U.S. manufacturers, the model is assessed following a structural equation modeling methodology. The results indicate that JIT‐purchasing has a direct positive relationship with agile manufacturing while the positive relationship between JIT‐production and agile manufacturing is mediated by JIT‐purchasing. The results also indicate that agile manufacturing has a direct positive relationship with the operational performance of the firm, that the operational performance of the firm has a direct positive relationship with the marketing performance of the firm, and that the positive relationship between the operational performance of the firm and the financial performance of the firm is mediated by the marketing performance of the firm.

Smart self-healing micro/nanocontainers that heal cracks in the coating by releasing active compounds in response to external stimuli were reviewed.

Two studies examined narcissism and behavior in a commons dilemma. Study 1 used a four-person, laboratory-based task and Study 2 used a dyadic task. Participants were told that they represented one of four (Study 1) or two (Study 2) forestry companies and then were asked to harvest timber from a renewable forest. Narcissism was found to be positively related to acquisitive goals and harvesting more timber in the initial round. The more narcissists harvesting in the competitive group of four (Study 1) or dyad (Study 2), the less timber was harvested overall and the more rapidly the forest was depleted. Within competitive groups and dyads, however, narcissists harvested more than the nonnarcissists competing with them. In all, narcissism provided a benefit to the self, but at a long-term cost to other individuals and to the commons.

This paper presents a method to solve the economic power dispatch problem with piecewise quadratic cost functions. The solution approach is hierarchical, which allows for decentral i zed computations. An advantage of this approach is the capability to optimize over a greater variety of operating conditions. Traditionally, one cost function for each generator is assumed. In this formulation multiple intersecting cost functions are assumed. This method has appl ication to fossil generation units capable of burning gas and oil , as well as other problems which result in multiple intersecting cost curves for a particular unit. The results show that the solution method is practical and valid for real-time application. The motivation for this research stems from the actual operational and planning problems of a large Southwestern Utility.

It is a great challenge to fully understand the microscopic dispersion and aggregation of nanoparticles (NPs) in polymer nanocomposites (PNCs) through experimental techniques. Here, coarse-grained molecular dynamics is adopted to study the dispersion and aggregation mechanisms of spherical NPs in polymer melts. By tuning the polymer-filler interaction in a wide range at both low and high filler loadings, we qualitatively sketch the phase behavior of the PNCs and structural spatial organization of the fillers mediated by the polymers, which emphasize that a homogeneous filler dispersion exists just at the intermediate interfacial interaction, in contrast with traditional viewpoints. The conclusion is in good agreement with the theoretically predicted results from Schweizer et al. Besides, to mimick the experimental coarsening process of NPs in polymer matrixes (ACS Nano 2008, 2, 1305), by grafting polymer chains on the filler surface, we obtain a good filler dispersion with a large interparticle distance. Considering the PNC system without the presence of chemical bonding between the NPs and the grafted polymer chains, the resulting good dispersion state is further used to investigate the effects of the temperature, polymer-filler interaction, and filler size on the filler aggregation process. It is found that the coarsening or aggregation process of the NPs is sensitive to the temperature, and the aggregation extent reaches the minimum in the case of moderate polymer-filler interaction, because in this case a good dispersion is obtained. That is to say, once the filler achieves a good dispersion in a polymer matrix, the properties of the PNCs will be improved significantly, because the coarsening process of the NPs will be delayed and the aging of the PNCs will be slowed.

This paper discusses the limitations of time-based equipment maintenance methods and the advantages of predictive or online maintenance techniques in identifying the onset of equipment failure. The three major predictive maintenance techniques, defined in terms of their source of data, are described as follows: 1) the existing sensor-based technique; 2) the test-sensor-based technique (including wireless sensors); and 3) the test-signal-based technique (including the loop current step response method, the time-domain reflectrometry test, and the inductance-capacitance-resistance test). Examples of detecting blockages in pressure sensing lines using existing sensor-based techniques and of verifying calibration using existing-sensor direct current output are given. Three Department of Energy (DOE)-sponsored projects, whose aim is to develop online and wireless hardware and software systems for performing predictive maintenance on critical equipment in nuclear power plants, DOE research reactors, and general industrial applications, are described.

Global polarization of $\mathrm{\ensuremath{\Lambda}}$ hyperons has been measured to be of the order of a few tenths of a percentage in Au+Au collisions at $\sqrt{{s}_{{}_{NN}}}$ = 200 GeV, with no significant difference between $\mathrm{\ensuremath{\Lambda}}$ and $\overline{\mathrm{\ensuremath{\Lambda}}}$. These new results reveal the collision energy dependence of the global polarization together with the results previously observed at $\sqrt{{s}_{{}_{NN}}}$ = 7.7--62.4 GeV and indicate noticeable vorticity of the medium created in noncentral heavy-ion collisions at the highest Relativistic Heavy Ion Collider collision energy. The signal is in rough quantitative agreement with the theoretical predictions from a hydrodynamic model and from a multi-phase transport model. The polarization is larger in more peripheral collisions, and depends weakly on the hyperon's transverse momentum and pseudorapidity ${\ensuremath{\eta}}^{H}$ within $|{\ensuremath{\eta}}^{H}|<1$. An indication of the polarization dependence on the event-by-event charge asymmetry is observed at the $2\ensuremath{\sigma}$ level, suggesting a possible contribution to the polarization from the axial current induced by the initial magnetic field.

Presents an AHP (analytical hierarchy process) decision model for facility location selection from the view of organizations which contemplate locations of a new facility or a relocation of existing facilities. The AHP model provides a framework to assist managers in analysing various location factors, evaluating location site alternatives, and making final location selections. The primary principle of the AHP model is to match decision‐makers’ preferences with location site characteristics. The model requires that a number of potential sites have been proposed. Alternatives are then evaluated and compared under both quantitative and qualitative factors to allow managers to incorporate managerial experiences and judgement in the solution process. Uses an example problem to illustrate the solution process. Addresses managerial implications for future research.

Carbon nanofibers (CNFs) suspended epoxy resin nanocomposites and the corresponding polymer nanocomposites are fabricated. The surface of CNFs is introduced a functional amine terminated groups via silanization, which in situ react with epoxy monomers. This in situ reaction favors the CNFs dispersion and improves the interfacial interaction between CNFs and monomers. Effects of particle loading, surface treatment and operating temperatures of rheological tests on the complex viscosity, storage modulus and loss modulus are systematically studied. Unique rheological phenomena “a decreased viscosity with a better dispersion” are observed and explained in terms of the improved filler dispersion quality. Meanwhile, significant increase in the tensile property and storage modulus is observed and related to the better dispersion and the introduced strong interfacial interaction as revealed by SEM imaging. Finally, electrical conductivity is investigated and an unusual deficiency of surface treatment to improve the electrical conductivity is explained by an insulating coating layer.

Mercury pollution control has become a global goal. The accurate estimate of long-term mercury emissions in China is critical to evaluate the global mercury budget and the emission reduction potentials. In this study, we used a technology-based approach to compile a consistent series of China's atmospheric mercury emissions at provincial level from 1978 to 2014. China totally emitted 13 294 t of anthropogenic mercury to air during 1978-2014, in which gaseous elemental mercury, gaseous oxidized mercury, and particulate-bound mercury accounted for 58.2%, 37.1%, and 4.7%, respectively. The mercury removed during this period were 2085 t in coal-fired power plants (counting 49% of mercury input), 7259 t in Zn smelting (79%), 771 t in coal-fired industrial boilers (25%), and 658 t in cement production plants (27%), respectively. Annual mercury emissions increased from 147 t in 1978 to 530 t in 2014. Both sectoral and spatial emissions of atmospheric mercury experienced significant changes. The largest mercury emission source evolved from coal-fired industrial boilers before 1998, to zinc smelting during 1999-2004, coal-fired power plants during 2005-2008, finally to cement production after 2009. Coal-fired industrial boilers and cement production have become critical hotpots for China's mercury pollution control.

The bond behavior of reinforcing bars in concrete is a critical issue in the design of reinforced concrete structures. This study focuses on the bond strength of fiber reinforced polymer (FRP) rebars in normal strength concrete. Four different types of rebars were tested using the pullout method: aramid FRP (AFRP); carbon FRP (CFRP); glass FRP (GFRP), and steel. This involved a total of 151 specimens containing 6, 8, 10, 16, and 19mm rebars embedded in a 203mm concrete cube. The test embedment lengths were five, seven, and nine times the rebar diameter (db) . For each rebar, the test results include the bond stress–slip response and the mode of failure. The test results showed that the bond strength of an FRP rebar is, on average, 40–100% the bond strength on a steel rebar for pullout failure mode. Based on this research, a proposal for the average bond strength of straight FRP rebars in normal strength concrete is made, which verifies an existing bond strength relationship (GFRP) and extends its application to AFRP and CFRP. It is an expression that is a function of the rebar diameter, and the concrete compressive strength.