Showing papers by "Iowa State University published in 1981"
746 citations
TL;DR: In this article, the authors provide evidence for a universal relationship between metallic binding energies and lattice parameters, and obtain binding energies as a function of atomic separation for bimetallic interfaces and bulk metals.
Abstract: We provide evidence for a universal relationship between metallic binding energies and lattice parameters. By a simple scaling of a universal relationship, one can obtain binding energies as a function of atomic separation for bimetallic interfaces and bulk metals.
638 citations
TL;DR: In this paper, a mathematical formulation of the optimal reactive power control (optimal VAR control) problem and results from tests of the algorithm are presented in order to minimize the real power losses in the system.
Abstract: A mathematical formulation of the optimal reactive power control (optimal VAR control) problem and results from tests of the algorithm are presented in this paper. The model minimizes the real power losses in the system. The constraints include the reactive power limits of the generators, limits on the load bus voltages, and the operating limits of the control variables, i.e., the transformer tap positions, generator terminal voltages and switchable reactive power sources. Real power economic dispatch is accomplished by standard techniques.
367 citations
TL;DR: In this article, a review and discussion of membrane transport theory with application to the reverse osmosis and ultra-filtralion processes is presented, focusing on two particular types of membranes, cellulose acetate (CA) and aromatic polyamide (AP) membranes.
Abstract: After a brief introduction to membrane processes in general, and the reverse osmosis process in particular, the structure and properties of membranes and membrane transport theory are described. The mechanism of salt rejection and transport properties of membranes are discussed in detail. Solubility, diffusivity, and permeability of membranes to solutes and solvents are reviewed critically and compared with each other. Special attention is given to two particular types of membranes, cellulose acetate (CA) and aromatic polyamide (AP) membranes, which are often used for water desalination. The major portion of this article is devoted to the review and discussion of membrane transport theory with application to the reverse osmosis and ultrafiltralion processes. It is shown that the solvent flux can be represented reasonably well by linear models such as the solution-diffusion model (Lonsdale, et al., 1965). The contribution of pore flow to the solvent flux is small. The solute flux, however, is not ...
297 citations
TL;DR: Attention is drawn to a forthcoming publication of optical data on all the metallic elements in the photon energy range 0.1--500 eV.
Abstract: Attention is drawn to a forthcoming publication of optical data on all the metallic elements in the photon energy range 01--500 eV (AIP)
220 citations
TL;DR: In this paper, various notions of multivariate negative dependence are introduced and their interrelationship is studied, and examples are given to illustrate these concepts in statistics and probability are given.
Abstract: Various notions of multivariate negative dependence are introduced and their interrelationship is studied. Examples are given to illustrate these concepts. Applications of the results in statistics and probability are given.
219 citations
TL;DR: In this paper, the response of 10 simple carbohydrates was investigated voltammetrically at platinum electrodes in 0.10 M sodium hydroxide by application of a conventional linear sweep waveform and a triple-pulse waveform.
214 citations
TL;DR: Bovine polymorphonuclear leukocytes were isolated from the peripheral blood of cattle to evaluate PMN function and normal values for bovine PMNs are reported and interpretation of results is discussed.
198 citations
TL;DR: In this article, the London equations with a phenomenlogical mass tensor were used to analyze the vortex structure near the lower critical field and the strongly anisotropic attenuation length was evaluated.
Abstract: The London equations with a phenomenlogical mass tensor are used to analyze the vortex structure near the lower critical field. The anisotropy results in a transverse magnetic field in the Abrikosov vortex. This field attenuates exponentially at large distances from the vortex axis. The strongly anisotropic attenuation length is evaluated. The line energy is found in the London approximation.
192 citations
TL;DR: In this article, various methods of social skills assessment with children were reviewed, based upon an extensive review of the literature, it was found that behavioral observations, sociometrics, and teacher ratings have been the most often used methods of assessing children's social skill deficits.
185 citations
TL;DR: Genetic correlations between reproductive performance and 60-day, 180- day, and 305-day fat-corrected-milk-yields were positive, indicating that higher producing cows were bred later, took longer to conceive, and required more services per conception.
TL;DR: The traditional method for estimating or predicting linear combinations of the fixed effects and realized values of the random effects in mixed linear models is first to estimate the variance components and then to proceed as if the estimated values of variance components were the true values as mentioned in this paper.
Abstract: The traditional method for estimating or predicting linear combinations of the fixed effects and realized values of the random effects in mixed linear models is first to estimate the variance components and then to proceed as if the estimated values of the variance components were the true values. This two-stage procedure gives unbiased estimators or predictors of the linear combinations provided the data vector is symmetrically distributed about its expected value and provided the variance component estimators are translation-invariant and are even functions of the data vector. The standard procedures for estimating the variance components yield even, translation-invariant estimators.
TL;DR: The methodology presented may serve as a simple diagnostic tool for early revealing of the deficiency of the subject's locomotion system and may allow some preventive action to be taken to delay or cancel the process of joint degeneration.
TL;DR: The elastic constants of Ni3Al were determined at 0 and 23.5 °C by ultrasonic measurements performed on a single crystal (with parallel sets of (110), (110, and (001) faces).
Abstract: The elastic constants of Ni3Al are determined at 0 and 23.5 °C by ultrasonic measurements performed on a single crystal (with parallel sets of (110), (110), and (001) faces) of stoichiometric Ni3Al. The (adiabatic) ice point values, which are estimated to be accurate to within ±0.2%, are as follows: C11 = 2.243, C12 = 1.486, C44 = 1.258 × 1011 N/m2. The C44 and C12 are within about 2% of the corresponding values for pure nickel. The C11 of Ni3Al is smaller than that of pure nickel by about 12% resulting in a significantly higher elastic anisotropy for the ordered alloy as opposed to the pure metal. The experimental data are used to calculate the elastic moduli of polycrystalline Ni3Al possessing a random distribution of crystallite orientations. Both the Cij and polycrystalline moduli values reported here differ significantly from published results for this alloy.
TL;DR: In this paper, single crystals of n-WSe2 and n-MoSe2 were grown and employed as the photoanode in a regenerative photoelectrochemical cell with an iodide/triiodide electrolyte.
TL;DR: A new technique for modelling the signal and the measurements is developed based on Kalman Filtering theory for the optimal estimation of the 60 Hz information and results indicate that the technique converges to the true 60 Hz quanitities faster than other algorithms that have been used.
Abstract: During the first cycle following a power system fault, a high speed computer relay has to make a decision usually based on the 60 Hz information, which is badly corrupted by noise The noise in this case is the nonfundamental frequency components in the transient current or voltage, as the case may be For research and development purposes of computer relaying techniques, the precise nature of the noise signal is required The autocorrelation function and variance of the noise signal was obtained based on the frequency of occurrence of the different types of faults, and the probability distribution of fault location A new technique for modelling the signal and the measurements is developed based on Kalman Filtering theory for the optimal estimation of the 60 Hz information The results indicate that the technique converges to the true 60 Hz quanitities faster than other algorithms that have been used The new technique also has the lowest computer burden among recently published algorithms and appears to be within the state of the art of current microcomputer technology
TL;DR: In this paper, the authors report the results of a study of the motivational implications of the industrial salesperson's personal characteristics and his or her perceptions of the job, the company's organization.
Abstract: The author reports the results of a study of the motivational implications of the industrial salesperson's personal characteristics and his or her perceptions of the job, the company's organization...
TL;DR: In this paper, the prediction of the (n + s)th observation of the pth order autoregressive process is investigated and the mean square of the predictor error through terms of order n −1, conditional on Yn, Y n 1, 1, ε, δ n − p + 1, is obtained for the stationary normal process.
Abstract: The prediction of the (n + s)th observation of the pth order autoregressive process is investigated. The mean square of the predictor error through terms of order n —1, conditional on Yn, Y n — 1, …, Y n — p + 1, is obtained for the stationary normal process. The mean squared error expression is similar to the usual regression formula for the variance of the predictor error. The usual regression formula for the estimated variance of a predictor error and its generalization to s-period prediction is shown to provide a consistent estimator of the mean squared error of the least squares predictor for both stationary and non-stationary processes.
TL;DR: In this article, direct methods of transient stability analysis of a multi-machine power system, using a function describing the system's transient energy, are discussed, and the following fundamental questions are dealt with: the concept of a controlling unstable equilibrium point (u.p.), the manner in which some generators tend to lose synchronism, and identifying-the energy directly responsible for system separation.
Abstract: Direct methods of transient stability analysis of a multi-machine power system, using a function describing the system's transient energy, are discussed. By examining the trajectory of the disturbed system, the following fundamental questions are dealt with: the concept of a controlling unstable equilibrium point (u.e.p.), the manner in which some generators tend to lose synchronism, and identifying-the energy directly responsible for system separation. Resolving these issues will substantially improve transient stability analysis by a direct method.
TL;DR: A large number of species of Amphibia, both Anura and Urodela, are capable of tolerating a moderately saline environment, and Rana cancrivora, Bufo viridis, and Xenopus laevis are among the most euryhaline frogs so far studied.
Abstract: A large number of species of Amphibia, both Anura and Urodela, are capable of tolerating a moderately saline environment. Rana cancrivora, Bufo viridis, and Xenopus laevis are among the most euryhaline frogs so far studied. Rana cancrivora can tolerate undiluted seawater. In a saline environment, Amphibia show raised plasma sodium and chloride and raised intracellular potassium and chloride. In the adults, plasma and tissue urea are elevated, especially in the more euryhaline species. Free amino acids contribute negligibly to plasma osmolarity, but are very important in intracellular fluids. By these various means, the osmotic pressure of body fluids is always maintained at a higher level than that of the surroundings. Larval Amphibia, however, do not make urea; Rana cancrivora tadpoles can live in saltwater, but maintain the osmolarity of their body fluids below that of their surroundings.
Adaptive responses to hyperosmolar environment include decreased skin sodium transport, greatly reduced urine flow, and release of posterior pituitary hormones. After the initial response, the release of these hormones declines, and urine flow increases. Accumulation of urea occurs slowly, but this substance plays an increasingly important role as adaptation proceeds. Accumulation is due initially to urea retention, and possibly to greater synthesis due to a high concentration of precursors of the urea cycle. In later stages of adaptation, increased urea synthesis is due to elevated levels of urea cycle enzymes, especially those that appear to have been rate-limiting. Liver glutamate dehydrogenase is also elevated. In animals subjected to pure osmotic stress, in solutions not containing sodium, responses are similar to, but not identical with, those caused by a medium containing sodium chloride.
TL;DR: Comparison shows that healthy subjects definitely possess a more efficient shock-absorbing capacity than do those subjects with joint disorders, and that degenerative changes in joints reduce their shock absorbing capacity, which leads to overloading of the next shock absorber in the locomotor system.
Abstract: A method to measure the capability of the human shock absorber system to attenuate input dynamic loading during the gait is presented. The experiments were carried out with two groups: healthy subjects and subjects with various pathological conditions. The results of the experiments show a considerable difference in the capability of each group's shock absorbers to attenuate force transmitted through the locomotor system. Comparison shows that healthy subjects definitely possess a more efficient shock-absorbing capacity than do those subjects with joint disorders. Presented results show that degenerative changes in joints reduce their shock absorbing capacity, which leads to overloading of the next shock absorber in the locomotor system. So, the development of osteoarthritis may be expected to result from overloading of a shock absorber's functional capacity.
TL;DR: In this paper, the authors investigated the spontaneous oscillations observed when a high-viscosity fluid jet flows vertically against a flat surface, and the minimum distance from the jet orifice to the flat surface for which these oscillations are observed, termed the buckling height, was determined experimentally.
Abstract: Experimental results are presented concerning the spontaneous oscillations observed when a high-viscosity fluid jet flows vertically against a flat surface. The two jet shapes investigated were the axisymmetric jet and the plane jet. The minimum distance from the jet orifice to the flat surface for which these oscillations are observed, termed the ‘buckling height’, was determined experimentally. The frequency of the subsequent oscillations was also determined. Both were measured as functions of fluid and flow variables. It is found that surface tension effects are the dominant factors influencing the buckling height, while the rate of oscillation is affected by both surface tension effects and by viscous, gravity and inertia effects. The major results are presented in non-dimensional form. Photographs of the buckling phenomenon are provided for representative jet geometries. It is also established experimentally that there is an upper limit to the flow Reynolds number above which buckling does not occur.
TL;DR: In this paper, the regularity properties of the Dirichlet and Neumann nonhomogeneous problems were investigated under the action of a boundary forcing term in L 2 (0,T; L 2(Γ)).
Abstract: This paper investigates the regularity properties of the solution of a second-order hyperbolic equation defined over a bounded domain ź with boundary Γ, under the action of a boundary forcing term inL2(0,T; L2(Γ)). Both Dirichlet and Neumann nonhomogeneous cases are considered. A functional analytic model based on cosine operator functions is presented, which provides an input-solution formula to be interpreted in appropriate topologies. With the help of this model, it is shown, for example, that the solution of the nonhomogeneous Dirichlet problem is inL2(0,T; L2(ź)), when ź is either a parallelepiped or a sphere, while the solution of the nonhomogeneous Neumann problem is inL2(0,T; H3/4-e(ź)) when ź is a parallelepiped and inL2(0,T; H2/3(ź) when ź is a sphere. The Dirichlet case for general domains is studied by means of pseudodifferential operator techniques.
TL;DR: A number of papers in this seminar are devoted to the production and characterization of cellulases, which are perhaps the most feasible method of converting cellulose to products that may be used for fuels and chemicals.
Abstract: A number of papers in this seminar are devoted to the production and characterization of cellulases. This is proper, since the use of cellulases is perhaps the most feasible method of converting cellulose to products that may be used for fuels and chemicals. However, all celluloses from hardwoods and grasses are associated with significant amounts of xylan, a hemicellulose possessing a β-l,4-linked xylose backbone, with branches containing xylose and other pentoses, hexoses, and uronic acids (Figure 1).
TL;DR: The present study suggests that xylazine-induced hyperglycemia and hypoinsulinemia are mediated by alpha 2-adrenergic receptors, possibly in beta-cells of pancreatic islets which inhibit the release of insulin.
Abstract: The mechanism by which xylazine raises plasma glucose but lowers insulin concentrations was examined in Holstein cows Intravenous injection of xylazine (15–150 μg/kg) induced a dose-dependent hyperglycemia and hypoinsulinemia for 3–4 h An α2-adrenergic blocking agent, yohimbine, and an α1 and α2-adrenergic blocking agent, phentolamine, at 500 μg/ kg each reduced or abolished xylazine-induced hyperglycemia and hypoinsulinemia The α1-adrenergic blocking agents, prazosin and phenoxybenzamine, at 500 μg/kg each did not exert such antagonism Prazosin at the dose studied even prolonged xylazine-induced hypoinsulinemia The α-adrenergic blocking agents alone at 500 μg/kg each did not change either plasma glucose or insulin concentrations The present study suggests that xylazineinduced hyperglycemia and hypoinsulinemia are mediated by α2-adrenergic receptors, possibly in β-cells of pancreatic islets which inhibit the release of insulin The present study further suggests the use of xylazine as a pharmacologi
TL;DR: Genetic and phenotypic correlations indicated that selection for increased peak yield would be associated with increased ln(a), b, and c without changing persistency or week of peak yield.
TL;DR: A set of criteria that has guided the development of a metric system for measuring the quality of a largescale software product is state, which uses the flow of information within the system as an index of system interconnectivity.
TL;DR: It is proposed that the preventative action of the low-calcium diet is associated with preparation of the calcium homeostatic mechanism several days before the calcium demand of initiation of lactation.
TL;DR: Major achievements in understanding pathogenesis of lactation ketosis, milk fever, grass tetany, and downer cow complex are reviewed, and future areas of research that seem worthy of additional investigation for these diseases are speculated upon.
TL;DR: In the spinal cord slice preparation the excitatory action of CCK-8 persists even when the spinal cords are perfused with a Ca2+-free, Mg2-high Krebs solution, which indicates that the action ofCCK- 8 might be a direct one exerted on the postsynaptic sites of dorsal horn units.