Showing papers by "Texas A&M University published in 1984"
TL;DR: In this paper, the authors report results from a series of studies designed to directly test a categorization-based model of leadership perceptions in three areas: specifying the internal structure of leadership categories, investigating the accessibility and importance of various individual behaviors in making leadership judgments, and explaining leadership perception in terms of categorization.
1,232 citations
TL;DR: This article explored the themes used by married couples, dating couples, relatives, live-in friends, and non-live-in friend to interpret their current relational episodes, and found that dating couples used themes of commitment, fragility, and manipulation, while marital couples, family members, and live-insignificant others used themes such as involvement, work, and respect.
Abstract: This study explored the themes used by married couples, dating couples, relatives, live‐in friends, and non‐live‐in friends to interpret their current relational episodes. One hundred eighteen people participated in fifty‐five report tasks. Among the findings were that dating couples used themes of commitment, fragility, and manipulation, while marital couples, relatives, and live‐in friends used themes of involvement, work, and respect.
1,129 citations
TL;DR: From longitudinal data from 129 nursing department employees, organizational commitment was found to be antecedent to job satisfaction rather than an outcome of it, and several other variables were causally related to satisfaction but not commitment as mentioned in this paper.
Abstract: From longitudinal data from 129 nursing department employees, organizational commitment was found to be antecedent to job satisfaction rather than an outcome of it Furthermore, several other variables were found to be causally related to satisfaction but not commitment Implications of unsubstantiated assumptions regarding causes of commitment are discussed
1,027 citations
TL;DR: The results clearly show that like "dioxin", the PCBs and PBBs elicit their effects through a cytosolic receptor protein which preferentially binds with the toxins which are approximate isostereomers of 2,3,7,8-TCDD.
Abstract: (1984). Polychlorinated Biphenyls (PCBs) and Polybrominated Biphenyls (PBBs): Biochemistry, Toxicology, and Mechanism of Action. CRC Critical Reviews in Toxicology: Vol. 13, No. 4, pp. 319-395.
781 citations
TL;DR: In this paper, the rate of oxygen evolution on substituted perovskites containing first-row transition metal ions has been studied at equilibrium and at an overpotential of 0.3V.
Abstract: Measurements of the oxygen evolution reaction have been made on eighteen substituted perovskites containing first‐row transition metal ions. Rates are reported at equilibrium and at an overpotential of 0.3V. Electrode kinetic parameters are given, including roughness factors. The rate does not depend on semiconductor‐type properties. It increases as the pH of zero charge, at which the occupancy of OH− and H+ at the interface becomes equal, moves in an alkaline direction, with decrease of magnetic moment, with decrease of stability of the perovskite lattice, with decrease of the enthalpy of formation of the transition metal hydroxides, and with increase in the number of d‐electrons in the transition metal ion. The accuracy of the roughness factor measurements are affected by weakness in knowledge of true double layer capacities. The value assumed here, 60 μF cm−2, may be accurate to only ± 100%. Models are given which suggest that the pores are active throughout. The correlations between the rate and electronic properties are consistent with rate‐determining steps which involve desorption of OH radicals, e.g., . An MO discussion suggests that the electrocatalysis increases with increased occupancy of the antibonding orbitals of MZ‒OH. Earlier interpretations include the concept that an increase of the rate occurs because of increasing overlap between the orbitals of the transition metal ion and the spσorbital of O. However, this theory is based on only three different materials, in which rate‐determining step changes. An interpretation based upon nonstoichiometry is shown to be consistent with observed trends, but insufficient to explain their magnitude. The electrical and chemical contributions to the rate are analyzed. The value of agr; is related via bond strength considerations to the MZ‒OH bond strengths. The relative electrocatalysis discussed is limited to an overpotential which corresponds to a practical range of rates on the faster catalysts. A volcano relation for oxygen evolution on perovskites seems likely. Future electrocatalysts are predicted.
777 citations
TL;DR: In this paper, a quasi-static deformation and fracture analysis for nonlinear viscoelastic media and sample applications are given. But the authors focus on predicting mechanical work available at the crack tip for initiation and continuation of growth.
Abstract: Methods of quasi-static deformation and fracture analysis are developed for a class of nonlinear viscoelastic media and sample applications are given. Selection of the class of media is guided by actual rheological behavior of monolithic and composite materials as well as the need for simplicity to be able to understand the effect of primary material and continuum parameters on crack growth behavior. First, pertinent aspects of J integral and energy release rate theory for nonlinear elastic media are discussed. Nonlinear viscoelastic constitutive equations are then given, and correspondence principles which establish a simple relationship between mechanical states of elastic and viscoelastic media are developed. These principles provide the basis for the subsequent extension of J integral theory to crack growth in viscoelastic materials. Emphasis is on predicting mechanical work available at the crack tip for initiation and continuation of growth; some examples show how viscoelastic properties and the J integral affect growth behavior. Included is the problem of a crack in a thin layer having different viscoelastic properties than the surrounding continuum. The Appendix gives an apparently new constitutive theory for elastic and viscoelastic materials with changing microstructure (e.g. distributed damage) and indicates the conditions under which the fracture theory in the body of the paper is applicable.
710 citations
641 citations
TL;DR: In this paper, the authors empirically examined differences in strategic variables between stages of the product life cycle (PLC), as well as differences among the determinants of high performance across stages of PLC.
Abstract: This study empirically examines differences in strategic variables between stages of the product life cycle (PLC), as well as differences among the determinants of high performance across stages of the PLC. The results support the use of the PLC as a contingency variable during strategy formulation. Implications for increasing market share and ROI are discussed.
601 citations
TL;DR: With some additional analytical improvements, isomer-specific PCB analysis can be utilized to determine the composition of commercial PCBs and accurately follow the fate and distribution of these pollutants within the global ecosystem.
Abstract: The synthesis and spectroscopic properties of all the mono-, di-, tri-, tetra-, penta-, hexa-, and heptachlorobipheynls are reported and the synthesis of all 209 polychlorinated biphenyls (PCBs) is completed. The retention times and molar response factors of the 209 PCBs were determined relative to a reference standard, octachloronaphthalene. The retention times for these compounds generally increased with increasing chlorine content, and it was apparent that within a series of isomers there was an increase in retention time with increasing meta and para and decreasing ortho substitution. By use of a 50-m narrow bore fused silica capillary column coated with SE-54, it was possible to separate 187 PCB congeners, and only 11 pairs of compounds were not fully resolved. With some additional analytical improvements, isomer-specific PCB analysis can be utilized to determine the composition of commercial PCBs and accurately follow the fate and distribution of these pollutants within the global ecosystem.
568 citations
TL;DR: The literature on modeling insect development rates is reviewed, the Sharpe and DeMichele model is described, and easy instructions for its use are presented.
Abstract: The importance of predicting the seasonal occurrence of insects has led to the formulation of many mathematical models that describe development rates as a function of temperature. Yet many of the widely used models do not provide acceptable results for predicting development times. After a careful review of the literature, we believe the biophysical model of Sharpe and DeMichele (1977; J. Theor. Biol. 64: 649–670) is the most suitable for this purpose. This model provides an excellent description of development rates over a full range of temperatures, and can be modified easily to describe rates over a portion of that range. Herein we review the literature on modeling insect development rates, describe the Sharpe and DeMichele model, and present easy instructions for its use. A computer program, assembled from the Statistical Analysis System (SAS) Library, determines the correct number of parameters to be used in the model for a given data set, selects starting values of these parameters for nonlinear regression, and computes least-square estimates of the parameters by using Marquardt techniques.
546 citations
01 Jan 1984
TL;DR: Canonical correlation analysis is a statistical method employed to investigate relationships among two or more variable sets, each consisting of at least two variables as discussed by the authors, which is the multivariate form of the general linear model, which presumes that all analyses are correlational, derive estimates by applying weights to measured variables, and yield variance-accounted-for effect sizes.
Abstract: Canonical correlation analysis is a statistical method employed to investigate relationships among two or more variable sets, each consisting of at least two variables. Canonical correlation analysis is the multivariate form of the general linear model, which presumes that all analyses are correlational, derive estimates by applying weights to measured variables, and yield variance-accounted-for effect sizes. As is the case throughout the GLM, noteworthy functions must be interpreted by consulting both standardized weights and structure coefficients in concert with each other.
Keywords:
multivariate statistics;
general linear model;
correlation;
experimentwise error;
structure coefficients
TL;DR: For instance, this paper found that a majority of repeat visitors were older individuals seeking relaxation and visiting a friend and/or relatives on their vacation, and the qualitative component of the study uncovered five factors which contributed to people returning to a familiar destination: a reduced risk that an unsatisfactory experience would be forthcoming; an assurance that they would find their kind of people there; emotional childhood attachment; to experience some aspects of the destination which had been omitted on a previous occasion; and to expose others to an experience which had previously been satisfying to respondents.
TL;DR: Etude experimentale d'un ecoulement d'air turbulent dans des conduites carrees avec 2 parois opposees a nervures en vue de determiner l'influence des rapports pas/hauteur des nervures and hauteur nervure/diametre equivalent sur le coefficient de frottement and les coefficients de transfert de chaleur for un nombre de Reynolds variant de 7000 a 90000 as discussed by the authors.
Abstract: Etude experimentale d'un ecoulement d'air turbulent dans des conduites carrees avec 2 parois opposees a nervures en vue de determiner l'influence des rapports pas/hauteur des nervures et hauteur nervure/diametre equivalent sur le coefficient de frottement et les coefficients de transfert de chaleur pour un nombre de Reynolds variant de 7000 a 90000
TL;DR: In this paper, some novel circuit techniques for realizing linear CMOS tranconductance elements are proposed, which have superior linearity and input voltage range compared with the conventional source-coupled differential pair.
Abstract: Some novel circuit techniques for realizing linear CMOS tranconductance elements are proposed. The circuits discussed have superior linearity and input voltage range compared with the conventional source-coupled differential pair. Design tradeoffs are examined and computer simulation results are used to verify theoretical predictions. The results show close agreement between predicted behavior and simulated performance.
TL;DR: For many years (Chalfant & Scheffelin, 1969) the diagnosis and evaluation of learning disabilities has been a major problem as mentioned in this paper, particularly since the passage of Public Law 94-142 (Education for All Handicapped Children Act of 1975).
Abstract: For many years (Chalfant & Scheffelin, 1969), but particularly since the passage of Public Law 94-142 (Education for All Handicapped Children Act of 1975), the diagnosis and evaluation of learning disabilities has presented major problems. The central one has been the problem of arriving at a workable definition of learning disability (LD). Education and psychology, the primary fields concerned with learning disabilities are low consensus fields, dealing with human behavior and theoretical constructs (of which LD is one). Much controversy has always existed regarding just what constitutes a learning disability. The rules and regulations for implementation of PL 94-142 provide a definition for use by multidisciplinary teams in deciding upon a diagnosis of LD. This definition states that a determination of LD:
TL;DR: The ionophore monensin is used as a model to examine the modes of action important in manipulating rumen function and increased animal production appears to occur as a result of these several system mode of action, which probably act in concert.
Abstract: The ionophore monensin is used as a model to examine the modes of action important in manipulating rumen function. Several system modes of action probably result from the basic mode of action of the ionophore modifying the movement of ions across the membranes of rumen microbes. While there are many biological responses reported in the literature for monensin, they can be consolidated into seven categories or system modes of action. The modification of volatile fatty acid production is one widely recognized category of great importance. Modified feed intake should also be considered to be important. The third system mode of action, change in gas production, probably contributes only a limited savings in energy. Modified digestibilities are probably quite variable as a mode of action, but may be a significant factor. The change in protein utilization appears to result from several factors that are occurring simultaneously. Modification of rumen fill and rate of passage may be important in causing some of the previously mentioned system modes of action to occur. A seventh category inclusive of several monensin responses that are more indirect to the rumen, or sporadic in nature, is included. Increased animal production from the use of monensin appears to occur as a result of these several system modes of action, which probably act in concert. It is impossible to accurately assess a quantitative contribution of each of these categories at the present time.
01 Dec 1984
TL;DR: In this paper, the effect of rib angle-of-attack on the pressure drop and the average heat-transfer coefficients in a fully developed turbulent air flow in a square duct with two opposite rib-roughened walls for Reynolds numbers varied from 7,000 to 90,000.
Abstract: Repeated rib-roughness elements have been used in advanced turbine cooling designs to enhance the internal heat transfer. Often the ribs are perpendicular to the main flow direction so that they have an angle-of-attack of 90 degrees. The objective of this investigation was to determine the effect of rib angle-of-attack on the pressure drop and the average heat-transfer coefficients in the fully developed turbulent air flow in a square duct with two opposite rib-roughened walls for Reynolds numbers varied from 7,000 to 90,000. The rib height-to-equivalent diameter ratio was kept at a constant value of 0.063, the rib pitch-to-height ratio was varied from 10 to 20, and the rib angle-of-attack (alpha) was varied from 90 to 60 deg to 45 to 30 deg, respectively. The thermal-performance comparison indicated that the increased heat conductance for the rib with an oblique angle to the flow (alpha = 45 deg - 30 deg) was about 10-20 percent higher than the rib with a 90 deg angle to the flow, and the pumping power requirement for the angled rib was about 20-50 percent lower than the transverse rib. Semi-empirical correlations for friction factor and heat-transfer coefficients were developed to account for rib spacing and rib angle. The correlations can be used in the design of turbine-blade cooling passages.
TL;DR: For instance, this article found that older children (9-10 years old and older) predicted that the actor's behaviors in new situations would be relatively consistent with the behavior that was observed or described, when the behavior was perceived to be a function of dispositional causal factors.
Abstract: RHOLES, WILLIAM S., and RUBLE, DIANE N. Children's Understanding of Dispositional Characteristics of Others. CHILD DEVELOPMENT, 1984, 55, 550-560. 2 studies are reported that concern children's use of personality traits and abilities to predict the behavior of other persons. In Study 1, subjects first observed vignettes that were designed to reveal an actor's abilities or personality traits. Then, they made predictions for the actor's behavior in other, related behavioral situations. In Study 2, subjects were told about 1 instance of an actor's behavior, and they were provided with covariation information that implied that the actor's behavior either was or was not caused by personal dispositions. Subjects then predicted the actor's behavior in related situations. In both studies the older subjects (9-10 years old and older) predicted that the actor's behaviors in new situations would be relatively consistent with the behavior that was observed or described, when the behavior was perceived to be a function of dispositional causal factors. Younger children (5-7 years old), on the other hand, did not predict that the actors' behaviors would be consistent across situations (regardless of their perceptions of the causes of the actors' behavior), even though they labeled the actors' behaviors with appropriate personality trait or ability terms (Study 1) and were able to use covariation information cues to infer dispositional causes (Study 2). These results suggest that younger children do not regard dispositional factors as stable, abiding characteristics of other persons.
TL;DR: DP was slightly enhanced in the bulk of the resin, as determined by a KBr-pellet technique, in comparison with results from a thin film method, but both techniques seem to provide useful and reproducible results for dental resins.
Abstract: Two methods of transmission Fourier Transform Infrared analysis were compared to determine the degree of polymerization (DP) in unfilled Bis-GMA-based dental resins. Diluent concentration, curing mode, and activator type were investigated. DP ranged from 55-72% and was highest for the most diluted resins. The effects of polymerization activation mode and type were insignificant. DP was slightly enhanced in the bulk of the resin, as determined by a KBr-pellet technique, in comparison with results from a thin film method, but both techniques seem to provide useful and reproducible results for dental resins.
TL;DR: Thermogenic gas hydrates were recovered from the upper few meters of bottom sediments in the northwestern Gulf of Mexico and were associated with oil-stained cores at a water depth of 530 meters.
Abstract: Thermogenic gas hydrates were recovered from the upper few meters of bottom sediments in the northwestern Gulf of Mexico. The hydrates were associated with oil-stained cores at a water depth of 530 meters. The hydrates apparently occur sporadically in seismic "wipeout" zones of sediments in a region of the Gulf continental slope at least several hundred square kilometers in area.
TL;DR: The West Philippine Basin was formed by spreading from the Central Basin Spreading Center in two distinctly different spreading phases, before and after subduction was initiated along the Palau-Kyushu trend at ~ 45 Ma B.P as discussed by the authors.
TL;DR: In this paper, a model system based on the combination of raw, gelatinized and dextrinized starch was used to represent the physicochemical properties of the extrudates.
Abstract: Corn starch extruded at 32.9, 29.2, 24.5, 22.5, 15.9 and 14.2% moisture was analyzed for expansion ratio, enzyme susceptibility, water solubility index, water absorption index, degree of gelatinization, paste viscosity and heat of gelatinization. A model system based on the combination of raw, gelatinized and dextrinized starch was used to represent the physicochemical properties of the extrudates. Reducing extrusion moisture content resulted in a progressive change from gelatinized-like to dextrinized-like properties. Maximum gelatinization was observed at about 28-29% moisture. Below 20% moisture, dextrinization becomes predominant during high- shear cooking-extrusion. Scanning electron micrographs also validate the assumptions of the model.
TL;DR: The paper reviews the development of environmental management in allied disciplines, offers a typology of strategies, discusses implementation issues, and presents implications of the perspective for marketing theory.
Abstract: Environmental management argues that marketing strategies can be implemented to change the context in which the organization operates, both in terms of constraints on the marketing function and lim...
TL;DR: A stochastic approach for modeling insect development based on a single, temperature-independent distribution of normalized development times, which can be used in population models to distribute cohort development through time under variable temperature conditions.
Abstract: We describe a stochastic approach for modeling insect development based on a single, temperature-independent distribution of normalized development times. We review other stochastic approaches, as well as problems encountered in modeling distributions of development time. A computer program, assembled from the Statistical Analysis System library, constructs cumulative probability distributions from frequency data on insect development times. These data are obtained from constant temperature experiments. The computer program normalizes the times of these distributions on their median time, identifies a single empirical distribution representative of all normalized distributions, and fits a cumulative Weibull function to this standard curve. The program determines the starting values of the three Weibull parameters and computes least-square estimates of these parameters using Marquardt techniques. This normalized probability function was tested against 23 data sets with good results, and can be used in population models to distribute cohort development through time under variable temperature conditions.
TL;DR: The normalized light scattering polarization matrix has been measured for ocean water using an electrooptic light scattering polarimeter and a simple one-component distribution was found to produce a reasonably good fit.
Abstract: The normalized light scattering polarization matrix has been measured for ocean water using an electrooptic light scattering polarimeter. Measurements were done on samples from the Atlantic and Pacific Oceans and the Gulf of Mexico. The polarization effects in the matrices were found to have, in general, a form which is similar to polarization effects in the Rayleigh scattering approximation; for example, all off-diagonal matrix elements except S12 and S21 were zero. Mueller matrix elements were calculated using a Mie computer code and compared to the measured matrices for ocean water. A simple one-component distribution was found to produce a reasonably good fit.
TL;DR: In this paper, a set of models were used to identify the most important of the following selected variables influencing international tourist flows to Turkey: per capita income; relative prices; relative exchange rate; promotional expenditure; and special events.
TL;DR: In this article, the authors made an evaluation based on seismic refraction data in combination with drilling results, laboratory studies of seismic properties of oceanic and ophiolitic rocks, and Ophiolite lithostratigraphy, and their preferred value for the mean density of the oceanic crust is 2.89±0.04 Mg m−3
Abstract: The density structure and average density of the oceanic crust have implications for various geological and geophysical problems, including interpretations of gravity data, the variation of lithospheric bouyancy in relation to age, and role and fate of the crust in subduction. But no systematic evaluation of oceanic crustal density has been made and estimates range from 2.85 to 3.0 Mg m−3 (refs 1–3). We have made an evaluation based on seismic refraction data in combination with drilling results, laboratory studies of seismic properties of oceanic and ophiolitic rocks, and ophiolite lithostratigraphy. Our preferred value for the mean density of the oceanic crust is 2.89±0.04 Mg m−3
TL;DR: This review discusses the various color forms of myoglobin in muscle and their relationship to species, atmospheric conditions, antemortem factors and storage characteristics.
Abstract: The color of fresh meat is important to every aspect of the meat industry. The basic explanations for various colors and intensities of color need to be understood in order to minimize off-colors which ultimately result in product loss. This review discusses the various color forms of myoglobin in muscle and their relationship to species, atmospheric conditions, antemortem factors and storage characteristics.