Showing papers by "University of Akron published in 2005"
TL;DR: In this paper, the authors investigated the relationships of the in-role performance and organizational citizenship behavior of the employees in an organization with their trust in their plant managers and found that the trust in managers was correlated with organizational citizenship behaviour.
Abstract: This study investigated the relationships of the in-role performance and organizational citizenship behavior (OCB) of the employees in an organization with their trust in their plant managers and t...
1,065 citations
TL;DR: It is found that the magnitude of pollen limitation observed in natural populations depends on both historical constraints and contemporary ecological factors.
Abstract: ▪ Abstract Quantifying the extent to which seed production is limited by the availability of pollen has been an area of intensive empirical study over the past few decades. Whereas theory predicts that pollen augmentation should not increase seed production, numerous empirical studies report significant and strong pollen limitation. Here, we use a variety of approaches to examine the correlates of pollen limitation in an effort to understand its occurrence and importance in plant evolutionary ecology. In particular, we examine the role of recent ecological perturbations in influencing pollen limitation and discuss the relation between pollen limitation and plant traits. We find that the magnitude of pollen limitation observed in natural populations depends on both historical constraints and contemporary ecological factors.
968 citations
TL;DR: N-Heterocyclic carbenes bind to both hard and soft metals making it a very versatile ligand system, and has been shown to equal, if not exceed, phosphines in their ability to bind to a variety of metals.
Abstract: Öfele and Wanzlick first pioneered the metalation of imidazol-2-ylidenes, better known as N-heterocyclic carbenes (NHCs), from imidazolium salts in 1968.1,2 Lappert and co-workers followed this work with the investigation of N-heterocyclic carbene complexes synthesized from electron-rich olefins.3,4 However, it was not until the isolation of the first free carbene by Arduengo, in 1991, that significant interest was given to the area.5 Since then the complexation chemistry of these new ligands has become a major area of research.6-10 This new class of ligand has shown to equal, if not exceed, phosphines in their ability to bind to a variety of metals. Complexes of N-heterocyclic carbenes with virtually every transition metal and many main group elements have been reported.1-10 N-Heterocyclic carbenes bind to both hard and soft metals making it a very versatile ligand system. NHCs bond to metals primarily through σ donation of the carbene lone pair to the metal. The bonding of the carbene was believed to have been purely σ donation in nature; however, recent evidence suggests that some degree of backdonation may occur.11,12 The bond strength of Nheterocyclic carbenes, as mentioned earlier, has been shown to rival phosphines. Due to this bonding * To whom correspondence should be addressed. Phone: (330)972-5362. E-mail: youngs@uakron.edu. 3978 Chem. Rev. 2005, 105, 3978−4008
950 citations
TL;DR: In this article, a theory of leadership development is presented, suggesting that changes in leadership skills may be viewed from the perspective of a general theory of learning and expertise, with consideration of the associated changes in information processing and underlying knowledge structures that occur as skill develops.
Abstract: A theory of leadership development is advanced, suggesting that changes in leadership skills may be viewed from the perspective of a general theory of learning and expertise, with consideration of the associated changes in information processing and underlying knowledge structures that occur as skill develops. More specifically, we propose that leadership performance is organized in terms of a progression from novice to intermediate to expert skill levels. At each skill level, the emphasis is on qualitatively different knowledge and information processing capabilities. In addition, because leadership skill development requires proaction on the part of the leader, we propose that identity, meta-cognitive processes, and emotional regulation are critical factors in developing the deeper cognitive structures associated with leadership expertise. Finally, expert leaders may develop unique skills in grounding their identities and leadership activities in coherent, self-relevant, authentic values.
759 citations
TL;DR: In this paper, a hierarchical pattern consisting of self-similar buckles extending over five orders of magnitude in length scale, ranging from a few nanometres to a few millimetres, is presented.
Abstract: Stiff thin films on soft substrates are both ancient and commonplace in nature; for instance, animal skin comprises a stiff epidermis attached to a soft dermis. Although more recent and rare, artificial skins are increasingly used in a broad range of applications, including flexible electronics, tunable diffraction gratings, force spectroscopy in cells, modern metrology methods, and other devices. Here we show that model elastomeric artificial skins wrinkle in a hierarchical pattern consisting of self-similar buckles extending over five orders of magnitude in length scale, ranging from a few nanometres to a few millimetres. We provide a mechanism for the formation of this hierarchical wrinkling pattern, and quantify our experimental findings with both computations and a simple scaling theory. This allows us to harness the substrates for applications. In particular, we show how to use the multigeneration-wrinkled substrate for separating particles based on their size, while simultaneously forming linear chains of monodisperse particles.
695 citations
TL;DR: The issue of resilience in relation to trauma and posttraumatic stress disorder is investigated as a multifaceted phenomena characterized as a complex repertoire of behavioral tendencies.
Abstract: Based on the available literature, this review article investigates the issue of resilience in relation to trauma and posttraumatic stress disorder. Resilient coping to extreme stress and trauma is a multifaceted phenomena characterized as a complex repertoire of behavioral tendencies. An integrative Person x Situation model is developed based on the literature that specifies the nature of interactions among five classes of variables: (a) personality, (b) affect regulation, (c) coping, (d) ego defenses, and (e) the utilization and mobilization of protective factors and resources to aid coping.
606 citations
TL;DR: The rate of bactericidal activity of 3 was greatly improved by encapsulation, and the amount of silver used was much reduced, so the silver mats were found effective against E. coli, P. aureus, C. albicans, A. niger, and S. cerevisiae.
Abstract: Silver(I)-imidazole cyclophane gem-diol complex, 3 [Ag2C36 N10(O)4](2+)2(x)-, where x = OH- or CO3(2-), was synthesized and well characterized. The minimum inhibition concentration tests showed that the aqueous form of 3 is 2 times less effective as an antibiotic than 0.5% AgNO3, with about the same amount of silver. The antimicrobial activity of 3 was enhanced when encapsulated into Tecophilic polymer by electrospinning to obtain mats made of nano-fibers. The fiber mats released nanosilver particles, which in turn sustained the antimicrobial activity of the mats over a long period of time. The rate of bactericidal activity of 3 was greatly improved by encapsulation, and the amount of silver used was much reduced. The amount of silver contained in the fiber mat of 3, with 75% of 3 and 25% Tecophilic, was 8 times less than that in 0.5% AgNO3 and 5 times lower than that in silver sulfadiazine cream 1%. The fiber mat was found to kill S. aureus at the same rate as 0.5% AgNO3, with zero colonies on an agar plate, and about 6 times faster than silver sulfadiazine cream. The silver mats were found effective against E. coli, P. aeruginosa, S. aureus, C. albicans, A. niger, and S. cerevisiae. Transmission electron microscopy and scanning electron microscopy were used to characterize the fiber mats. The acute toxicity of the ligand (imidazolium cyclophane gem-diol dichloride) was assessed by intravenous administration to rats, with an LD 50 of 100 mg/kg of rat.
541 citations
TL;DR: In this paper, the classical preisach hysteresis modeling and tracking control of a curved pre-stressed piezoceramic patch actuator system with severe hystresis is presented.
Abstract: This paper presents the classical Preisach hysteresis modeling and tracking control of a curved pre-stressed piezoceramic patch actuator system with severe hysteresis The actuator is also flexible with very small inherent damping It has potential applications in active antennas A series of tests are conducted to study the hysteresis properties of the piezoceramic actuator system The numerical expressions of the classical Preisach model for different input variations are presented The classical Preisach model is applied to simulate the static hysteresis behavior of the system Higher order hysteresis reversal curves predicted by the classical Preisach model are verified experimentally The good agreement found between the measured and predicted curves showed that the classical Preisach model is an effective mean for modeling the hysteresis of the piezoceramic actuator system Subsequently, the inverse classical Preisach model is established and applied to cancel the hysteresis the piezoceramic actuator system for the real-time microposition tracking control In order to improve the control accuracy and to increase damping of the actuator system, a cascaded PD/lead-lag feedback controller is designed with consideration of the dynamics of the actuator In the experiments, two cases are considered, control with major loop hysteresis compensation, and control with minor loop hysteresis compensation Experimental results show that RMS tracking errors are reduced by 50% to 70% if the hysteresis compensation is added in the feedforward path in both cases Therefore, hysteresis compensation with the feedback controller greatly improves the tracking control accuracy of the piezoceramic actuator
465 citations
TL;DR: In this paper, a recently developed procedure for performing multilevel confirmatory factor analysis (MCFA) is described, and an illustrative example of its application to leadership data reflecting both the organizational and societal level of analysis is provided.
Abstract: Statistical issues associated with multilevel data are becoming increasingly important to organizational researchers. This paper concentrates on the issue of assessing the factor structure of a construct at aggregate levels of analysis. Specifically, we describe a recently developed procedure for performing multilevel confirmatory factor analysis (MCFA) [Muthen, B.O. (1990). Mean and covariance structure analysis of hierarchical data. Paper presented at the Psychometric Society, Princeton, NJ; Muthen, B.O. (1994). Multilevel covariance structure analysis. Sociological Methods and Research, 22, 376–398], and provide an illustrative example of its application to leadership data reflecting both the organizational and societal level of analysis. Overall, the results of our illustrative analysis support the existence of a valid societal-level leadership construct, and show the potential of this multilevel confirmatory factor analysis procedure for leadership research and the field of I/O psychology in general.
428 citations
TL;DR: In this paper, four service evaluation models are identified from the literature that are commonly offered to depict the relationships among the primary service evaluation constructs of sacrifice, service quality, service value, satisfaction, and behavioral intentions.
390 citations
TL;DR: This article examined the relative influence of economic resources, time constraints, gender ideology, sex, and gender on the performance of housework, child care, and emotion work, and found that gender construction, not sex, predicts emotion work and this performance reflects a key difference in men's and women's gendered constructions of self.
Abstract: Attempting to explain why biological sex remains the primary predictor of household labor allocation, gender theorists have suggested that husbands and wives perform family work in ways that facilitate culturally appropriate constructions of gender. To date, however, researchers have yet to consider the theoretical and empirical significance of emotion work in their studies of the gendered division of household labor. Using survey data from 335 employed, married parents, I examine the relative influence of economic resources, time constraints, gender ideology, sex, and gender on the performance of housework, child care, and emotion work. Results indicate that gender construction, not sex, predicts the performance of emotion work and that this performance reflects a key difference in men's and women's gendered constructions of self.
TL;DR: In this paper, the authors reviewed evidence that has accumulated in favor of lamellar twist induced by surface stresses that result from differential congestion of fold surfaces, as suggested initially (in 1984) and advocated for many years by Keith and Padden.
TL;DR: In this paper, the authors studied the scale relations that are heavily conditioned by the administrative levels or ranks (dengji) of cities and counties in China's urban administrative/spatial system.
TL;DR: The concept of reciprocal trust between interacting teams is defined as the trust that results when a party observes the actions of another and reconsiders one's trust-related attitudes and subsequent behaviors based on those observations as discussed by the authors.
Abstract: This research develops and investigates the concept of reciprocal trust between interacting teams. Reciprocal trust is defined as the trust that results when a party observes the actions of another and reconsiders one's trust-related attitudes and subsequent behaviors based on those observations. Twenty-four teams of systems analysis and design students were involved in a 6-week controlled field study focused on the development of an information systems project. Each team was responsible for both developing a system (development role) and for supervising the development of a system by another team (management role). Risk-taking actions exhibited by one team in an interacting pair were found to predict the other team's trustworthiness perceptions and subsequent trust. The level of trust formed in turn predicted the team's subsequent risk-taking behaviors with respect to the other team. This pattern of reciprocal trust repeated itself as the teams continued to interact over the duration of the project, thus supporting our model of reciprocal trust. Findings also indicate that trust and trust formation can occur at the team level. Copyright © 2005 John Wiley & Sons, Ltd.
TL;DR: In this article, a fabrication process for constructing polymer surfaces with multiwalled carbon nanotube hairs, with strong nanometer-level adhesion forces that are 200 times higher than those observed for gecko foot-hairs, is described.
TL;DR: In this article, an exact solution for the multilayered rectangular plate made of functionally graded, anisotropic, and linear magneto-electro-elastic materials is presented.
TL;DR: Findings indicated that online learner participation and patterns of participation are influenced by the following factors: technology and interface characteristics, content area experience, student roles and instructional tasks, and information overload.
Abstract: This study explored what factors influenced learner participation in two sections of a graduate online course at a Midwestern university. Findings indicated that online learner participation and patterns of participation are influenced by the following factors: technology and interface characteristics, content area experience, student roles and instructional tasks, and information overload. Effective online learning requires interdependence for a shared understanding of learning goals in a learning community. Monitoring student participation and patterns of participation closely can help instructors identify student needs and scaffold learning accordingly.
TL;DR: The authors found that students in psychology of women classes would perform better on materials covered by multiple-choice exams when the first author presented these materials with active learning versus lecture, autonomous readings, and video presentations alone.
Abstract: We tested the hypothesis that students in psychology of women classes would perform better on materials covered by multiple-choice exams when the first author presented these materials with active learning versus lecture, autonomous readings, and video presentations alone. Across 3 classes, we coded exam items according to how the instructor presented relevant materials and recorded classwide performance. Both between and within classes, students' performances were better on items testing materials covered with active learning techniques compared to other formats. These data provide empirical support for the efficacy of active learning techniques.
TL;DR: It is concluded that echocardiographic features can predict which patients with prolapse are at highest risk for complications, and that mitral valve repair is the treatment of choice for symptomatic prolapse.
TL;DR: In this article, a review summarises patents published from 2001 to 2004 on the microcidal properties of silver-releasing materials for healthcare and medicine, including the anti-inflammatory, re-epitheliasation and anti-haemorrhagic properties of the materials.
Abstract: This review summarises patents published from 2001 to 2004 on the microcidal properties of silver-releasing materials for healthcare and medicine. The anti-inflammatory, re-epitheliasation and antihaemorrhagic properties of the silver-releasing materials are also disclosed. A biological evaluation of the anti-viral properties of silver tetra-silver tetra-oxide is discussed, but no biological data have been reported to support the claim that silver (I) has anti--viral prop-erties, as disclosed by most of the patents.
Journal Article•
TL;DR: Participants who had experienced negative life events in the 6 to 12 months prior to participating in the study had lower self-esteem than those who had similar stresses within the prior six months; the opposite was true for clinical suicidal ideators.
Abstract: The relationships among stress, self-esteem, and suicidal ideation in late adolescents were examined in a group of college students. Multiple regression analysis indicated that both stress and self-esteem were significantly related to suicidal ideation; low self-esteem and stressful life events significantly predicted suicidal ideation. The hypothesis that self-esteem would moderate the effects of life stressors on suicidal ideation was supported at the .06 level. A significant minority of the sample indicated having thoughts severe enough to be classified as clinical suicidal ideation. In general, participants who had experienced negative life events in the 6 to 12 months prior to participating in the study had lower self-esteem than those who had similar stresses within the prior six months. However, the opposite was true for clinical suicidal ideators; those who experienced negative life stressors recently had lower self-esteem than those who experienced negative life events six months to a year in the past.
TL;DR: In this article, a mesoporous silica material with a uniform pore size of 21 nm and a surface area of 200~230 m 2 /g was used for the capture of carbon dioxide from simulated flue gas streams.
TL;DR: In this paper, specific strength, moduli and fracture toughness of varied microstructures of syntactic foam was evaluated by using 3M Scotchlite ™ K15 and K46 glass bubbles, and Phenoset BJO-093 hollow phenolic microspheres.
TL;DR: In this paper, the role of matrix-mediated filler−filler interactions is explicitly illustrated in terms of the increased elastic modulus in the terminal region due to replacement a fraction of the matrix chains with longer chains of the same kind.
Abstract: We explore filler reinforcement (i.e., increase of elastic modulus G‘ due to incorporation of fillers) and Payne effect (i.e., decrease of G‘ at large strain amplitudes) in terms of the matrix molecular weight, filler loading, and time scales used to probe the viscoelasticity of filled melts. Use of monodisperse non-cross-linked 1,4-polybutadiene (PBD) along with a silica filler allows illustration of different mechanisms of filler reinforcement in the elastic and liquid regimes. The greater filler reinforcement for matrices of higher molecular weight indicates the filler association through chain adsorption and bridging. The role of matrix-mediated filler−filler interactions is explicitly illustrated in terms of the increased elastic modulus in the terminal region due to replacement a fraction of the matrix chains with longer chains of the same kind. The Payne effect is seen to be time-dependent and comprised of an instantly recoverable and a slowly recovering component. Measuring G‘ at both high and low...
TL;DR: Pyrene and 2,7-disubstituted pyrenes have been oxidized with ruthenium(III) chloride (RuCl3) and sodium periodate (NaIO4) under very mild conditions to 4,5-diones or 4, 5,9,10-tetraones.
Abstract: Pyrene and 2,7-disubstituted pyrenes have been oxidized with ruthenium(III) chloride (RuCl3) and sodium periodate (NaIO4) under very mild conditions to 4,5-diones or 4,5,9,10-tetraones. Thus, the oxidation has been controlled by varying the amount of oxidant and reaction temperature to proceed exclusively at the pyrene 4- and 5-positions or at the 4-, 5-, 9-, and 10-positions.
TL;DR: In this article, two onsets of anharmonicity are observed in the dynamics of the protein lysozyme, one at T approximately 100 K appears in all samples regardless of hydration level and is consistent with methyl group rotation.
Abstract: Two onsets of anharmonicity are observed in the dynamics of the protein lysozyme. One at T approximately 100 K appears in all samples regardless of hydration level and is consistent with methyl group rotation. The second, the well-known dynamical transition at T approximately 200-230 K, is only observed at a hydration level h greater than approximately 0.2 and is ascribed to the activation of an additional relaxation process. Its variation with hydration correlates well with variations of catalytic activity suggesting that the relaxation process is directly related to the activation of modes required for protein function.
TL;DR: In this paper, the authors analyzed mechanical properties and structure of polypropylene fibers with different concentrations of single-wall carbon nanotubes (SWNTs) and draw down ratios (DDR).
TL;DR: The work presented here represents an important advance in constructing many multicomponent nanotube structures for multifunctional material and device applications.
Abstract: Multicomponent structures were constructed by DNA-directed self-assembling of multiple carbon nanotubes and gold nanoparticles. The work presented here represents an important advance in constructing many multicomponent nanotube structures for multifunctional material and device applications.
TL;DR: This paper presents the modeling, simulation, and control aspects of four-quadrant switched reluctance motor (SRM) drives and describes a complex model for the physical motor simulation to incorporate the important dynamics of the SRM.
Abstract: This paper presents the modeling, simulation, and control aspects of four-quadrant switched reluctance motor (SRM) drives. The design of SRM drive systems must be focused on application-based appropriate control and engineering solutions needed to overcome the practical issues. A complex model is described for the physical motor simulation to incorporate the important dynamics of the SRM. A simpler, but quite accurate, model is presented for the SRM controller. Various practical limitations have been incorporated in the simulation model to make it closer to the experimental setup. The SRM control parameters are chosen based on torque-per-ampere maximization requirement. Experimental results for a 1.0-kW SRM obtained on a digital platform are presented along with useful guidelines for prototype implementation.
TL;DR: To improve the retention of enzymes in HMMS, adsorbed enzymes, and then employed crosslinking using glutaraldehyde (GA), and the resulting crosslinked enzyme aggregates (CLEAs) show an impressive stability with extremely high enzyme loadings.
Abstract: Hierarchically ordered mesocellular mesoporous silica materials (MMS) were synthesized using a single structure directing agent under neutral conditions for the first time. The mesocellular pores are synthesized without adding any pore expander, and the walls of cellular pores in MMS are composed of SBA-15 type mesopores. The small-angle X-ray scattering (SAXS) pattern of MMS revealed the presence of ordered pore structures with two different length scales. The current MMS possesses four different pore systems; complementary micro/mesopores, main 13 nm mesopores, 40 nm mesocellular spherical pores, and textural inter-particle macropores. Nanometer-scale enzyme reactors (NER) were developed in mesocellular mesoporous silica (MMS) via a ship-in-a-bottle approach, which employs adsorption of enzymes followed by cross-linking using glutaraldehyde (GA) treatment. The resulting NER show an impressive stability and activity with an extremely high loading of enzymes. For example, NER containing α-chymotrypsin (NER-CT) could hold 0.5 g CT in 1 g of silica, but the specific activity of NER-CT was 10.4 times higher than that of the adsorbed CT with a lower loading (0.07 g CT per 1 g of silica), which was further decreased by a continuous leaching of adsorbed CT. NER-CT showed excellent stability without any leaching, i.e. no activity decrease atmore » all in a rigorously-shaking condition for two weeks (a half-life with 3.8 years), while the conventional adsorption method resulted in a half-life of 3.6 days in the same condition.« less