Showing papers by "Brigham Young University published in 1980"
TL;DR: In this article, the effects of metal-support interactions on room-temperature H2 adsorption on alumina- and silica-supported Ni catalysts were investigated. But the results were limited to the case of Ni SiO 2 catalysts.
346 citations
TL;DR: It is demonstrated that in patchy environments of the proper scale and variability in quality, labile sexual expression will enhance an individual's genetic contribution to the next generation.
Abstract: Evidence is presented that individuals of a large number of dioecious and subdioecious plant species are able to alter their sexual state in response to changes in the ambient environment and/or changes in size or age. We suggest that lability of sexual expression probably has survival value where a significant portion of the females must otherwise bear the cost of fruit production in unfavorable environments. We demonstrate that in patchy environments of the proper scale and variability in quality, labile sexual expression will enhance an individual's genetic contribution to the next generation.
329 citations
TL;DR: In this paper, the authors investigated the properties of NiSiO2, NiAl2O3, and NiTiO2 catalysts representing wide ranges of dispersion and nickel concentration.
274 citations
TL;DR: Experiments using rapid-positioning movements in humans, where the subject is suddenly and unexpectedly provided with a change in the load characteristics of the limb, support a mass-spring model of unidirectional limb action and suggest that the role of phasing in motor programs may be different for uniddirectional actions on the one hand and multi-directional and/or multi-component actions onThe other.
Abstract: Experiments using rapid-positioning movements in humans, where the subject is suddenly and unexpectedly provided with a change in the load characteristics of the limb, are described. Taken together, the pattern of results supports a mass-spring model of unidirectional limb action, where the limb moves to a position defined by the relative tensions in the agonist and antagonist. As well, various results provide evidence contrary to predictions from an impulse-timing viewpoint, where the motor program times the onset of impulses to the musculature, and against a feedback-processing viewpoint, where limb position is defined by minimizing positioning error indicated by feedback. The evidence suggests that the role of phasing in motor programs may be different for unidirectional actions on the one hand and multi-directional and/or multi-component actions on the other.
246 citations
TL;DR: In this paper, the authors show that the expected value of R 2 is substantially inflated above its value without selection, especially when the number of observations is less than a small number of predictor variables, and the extent of this increase was investigated by a Monte Carlo simulation.
Abstract: When subset selection is used in regression the expected value of R 2 is substantially inflated above its value without selection, especially when the number of observations is less than the number of predictor variables. The extent of this increase was investigated by a Monte Carlo simulation. Tables are given with average values and percentage points of R 2 for the null case of independence between the response variable and the predictor variables. Approximation formulas are provided to supplement the coverage in the tables.
205 citations
TL;DR: The Pioneer Saturn vector helium magnetometer has detected a bow shock and magnetopause at Saturn and has provided an accurate characterization of the planetary field, indicating that the field is more uniform than those of the Earth or Jupiter and consistent with Saturn having a relatively small core.
Abstract: The Pioneer Saturn vector helium magnetometer has detected a bow shock and magnetopause at Saturn and has provided an accurate characterization of the planetary field. The equatorial surface field is 0.20 gauss, a factor of 3 to 5 times smaller than anticipated on the basis of attempted scalings from Earth and Jupiter. The tilt angle between the magnetic dipole axis and Saturn's rotation axis is < 1°, a surprisingly small value. Spherical harmonic analysis of the measurements shows that the ratio of quadrupole to dipole moments is < 10 percent, indicating that the field is more uniform than those of the Earth or Jupiter and consistent with Saturn having a relatively small core. The field in the outer magnetosphere shows systematic departures from the dipole field, principally a compression of the field near noon and an equatorial orientation associated with a current sheet near dawn. A hydromagnetic wake resulting from the interaction of Titan with the rotating magnetosphere appears to have been observed.
184 citations
TL;DR: In this paper, the Pioneer 11 vector helium magnetometer observations of Saturn's planetary magnetic field, magnetosphere, magnetopause, and bow shock were used to show that the magnetic field has a high degree of symmetry about the rotation axis.
Abstract: The paper deals with the Pioneer 11 vector helium magnetometer observations of Saturn's planetary magnetic field, magnetosphere, magnetopause, and bow shock. Models based on spherical harmonic analyses of measurements inside 8 Saturn radii show that the planetary field has a high degree of symmetry about the rotation axis. The vector dipole moment has a tilt angle of less than 1 deg and is offset along the polar axis by 0.04 plus or minus 0.02 Saturn radius. Equatorial offsets derived from the models show pronounced variability and could be consistent with a very small offset. Large impulsive field compressions are observed in the magnetosheath near noon. Multiple crossings of the bow shock are observed, and the absence of significant changes in field direction indicates that it is quasi-perpendicular.
139 citations
TL;DR: In this paper, a coal extract was analyzed by combined gas chromatography-mass spectrometry using glass capillary columns and a sulfur specific flame photometric detection was used to identify the sulfur-containing aromatic compounds.
130 citations
TL;DR: Regressions of relative abundance of photosynthetic types on climatic variables showed that both mean annual temperature and annual precipitation were equally reliable as predictors of C3−C4 biomass, although it is felt that temperature is of primary importance in explaining the observations.
Abstract: Based on the physiological characteristics and responses of C3, C4, and CAM plants to environmental factors, it is generally predicted that C4 and CAM plants will become more abundant with increasing temperature and decreasing precipitation. To test this prediction, the relative contribution of each photosynthetic type to total plant community biomass was examined at seven study areas along an altitudinal transect in southeastern Wyoming grassland. In going from high (2,652 m) to low (1,405 m) elevation along this transect, mean annual temperature increased and annual precipitation decreased.
127 citations
TL;DR: A novel instructional model for sequencing, syntheizing, and summarizing subject-matter content, which follows a general-to-detailed pattern of sequencing, as opposed to the hierarchically based sequences derived from Gagné-type task analyses.
Abstract: This paper describes a novel instructional model for sequencing, syntheizing, and summarizing subject-matter content. The importance of such models is discussed, along with the need for a significant change in the role of subject-matter structure in instruction. A “zoom-lens” analogy is presented to facilitate an understanding of the elaboration model of instruction. Some basic concepts and principles upon which the model is based are described. The basic unvarying components of the elaboration model are described. And finally, some variations in the model for different kinds of goals are described. The elaboration model follows a general-to-detailed pattern of sequencing, as opposed to the hierarchically based sequences derived from Gagne-type task analyses.
117 citations
TL;DR: In this article, a review of various procedures for the preparation of wall-coated open tubular columns for gas chromatography is presented, rationalized in terms of the chemistry of the glass surface and the factors which influence the nature and chromatographic performance of the stationary phase film.
TL;DR: In this paper, a more appropriate "underclass learning class" model of stratification is suggested, although no empirical support is found for a relationship between self-reported delinquent behavior and socioeconomic status of father's occupation.
Abstract: The apparent refutation by self-report studies of social class-related theories of juvenile delinquency is critically reviewed. Improper conceptualization and operationalization of “social class” are considered to be primary causes of inconsistent findings. A more appropriate “underclasslearning class” model of stratification is suggested. Although no empirical support is found for a relationship between self-reported delinquent behavior and socioeconomic status of father's occupation. indications are that social class is somewhat more related to self-reported delinquency using the underclass/earning class model. However, there is no reason to expect social class to emerge as a major correlate of delinquent behavior no matter how it is measured.
Journal Article•
TL;DR: All isomers of the parent phenanthro[b]thiophenes, namely, phenanthropo[1,2b] thiophene as mentioned in this paper, have been synthesized.
TL;DR: In this paper, a model of individual-worker incentives in alternative economic organizations (collective, communal, capitalist) is developed and the impact of various parameters on hours worked is examined in the framework of utility maximization.
TL;DR: Excess enthalpies, excess volumes, and excess Gibbs free energies are reported over the entire composition range for n-hexane + n-undecane at 298.15 and 308.15 K as discussed by the authors.
01 Jan 1980
TL;DR: This paper found a monotonically increasing relationship between rate and evaluations of the speaker on competence-related adjectives (with higher competence being attributed to higher speaking rates) and an inverted U relationship between the rate and evaluation of a speaker on benevolence related adjectives, with middle ranges of rate receiving the highest ratings.
Abstract: With the development of Fourier analysis and related speech synthesis techniques, it is possible to isolate experimentally the effects of one vocal paralinguistic feature at a time. So far, speech rate is the single dimension that has been found to have the most reliable and clear cut effects. The early studies found a monotonically increasing relationship between rate and evaluations of the speaker on competence-related adjectives (with higher competence being attributed to higher speaking rates) and an inverted U relationship between rate and evaluations of the speaker on benevolence-related adjectives (with middle ranges of rate receiving the highest ratings). There have been substantial methodological improvements in later studies with the development of experimental paradigms to assess the effects of rate manipulations on natural spontaneous speech, but the early findings remain essentially unchanged. New work is beginning using more sophisticated methods of analysing and synthesising temporal patterns rather than just increasing and decreasing rate.
TL;DR: The effects of carbon formation on methanation activity of nickel and nickel bimetallic catalysts were investigated in this paper, where carbon was deposited on these catalysts at 675-700 K, 1 atm, H2/CO = 2 and space velocities of 80,000 to 200,000 h−1 over a period of 24 hours.
Abstract: The effects of carbon formation on methanation activity of nickel and nickel bimetallic catalysts were investigated. Carbon was deposited on these catalysts at 675-700 K, 1 atm, H2/CO = 2 and space velocities of 80,000 to 200,000 h−1 over a period of 6-24 hours. Specific methanation activities were measured before and after carbon depositing treatments at 500-575 K, 1 atm H2/CO = 4 and space velocities of 100,000 h−1. The results show that Ni/Al2O3 loses 20-60% of its initial activity within 10-15 hours of treatment. Platinum and cobalt promoted nickel are significantly more resistant to deactivation by carbon. However, Ni-MoO2 is highly susceptible to deactivation, losing essentially all of its activity within a few hours. Data showing the effects of reaction conditions, metal concentration and catalyst composition on the extent of deactivation and the effects of deactivation on catalyst strength are presented and discussed
TL;DR: In this paper, a one-dimensional model was developed for pulverized coal combustors and gasifiers, which describes the response of a coal particle system to its thermal, chemical and physical environment.
Abstract: A one-dimensional model has been developed for pulverized coal combustors and gasifiers. The model describes the response of a coal particle system to its thermal, chemical and physical environment. Moisture vaporization, coal devolatilization, heterogeneous char oxidation, gas particle interchange, radiation, gas phase oxidation, primary and secondary stream mixing, and heat losses are considered. A predictor-corrector solution technique was used to solve the ordinary non-linear differential equations. Several combustor and gasifier predictions are shown. The model predictions are compared with experimental data. The effects of particle size and distribution are shown to be particularly important. Significant rate controlling processes include initial particle heat-up and char surface reaction.
TL;DR: Tadpole larvae of Chelyosoma productum Stimpson, unlike those of many other ascidians, are not predictably photonegative at the time of settling, which explains the clumped distribution of the species in both intertidal and subtidal habitats.
TL;DR: The utility of the carbon isotope method in studying plant-animal interactions in habitats containing both C3 and C4 plants is demonstrated, in spite of the fact that more time and energy must be spent to locate these food plants in some of the habitats studied.
Abstract: Food habits of Arphia conspersa Scudder and Arphia pseudonietana (Thomas) were studied along an altitudinal transect in southeastern Wyoming shortgrass mixed prairie. Stable carbon isotope ratios indicated that diets were significantly different between study sites, between species, and between sexes. These differences were found to be primarily related to the availability of different food plants along the transect, although species with the C3 pathway of photosynthesis were consumed in greater proportion than their availability in the habitat. The preference for C3 species is presumably related to their higher nutritional value and digestibility, in spite of the fact that more time and energy must be spent to locate these food plants in some of the habitats studied. This study demonstrates the utility of the carbon isotope method in studying plant-animal interactions in habitats containing both C3 and C4 plants.
TL;DR: The authors showed that the desire for an enriched job was a significant moderator of the enrichment-satisfaction relationship and found that direct assessments of the person's desire for job enrichment were much better moderators than indirect estimates inferred from urban-rural influences or work values.
TL;DR: Excess enthalpies, excess volumes, and excess Gibbs free energies are reported over the entire composition range for (methylcyclohexane + n -hexane) at 298.15 and 308.15 K as mentioned in this paper.
TL;DR: One hundred ninety-eight brand managers were examined on four important role decisions: role conflict, role clarity, job tension, and job satisfaction as discussed by the authors, and significant relationships were found only for involvement with product decisions and level of contact on the job satisfaction dimension.
Abstract: One hundred ninety-eight brand managers were examined on four important role decisions: role conflict, role clarity, job tension, and job satisfaction. Role conflict was significantly related to role clarity, job tension, and job satisfaction. Role clarity was related to job tension and job satisfaction at significant levels and job tension was significantly related to job satisfaction. All relationships occurred in the expected directions. Four independent variables were analyzed with these four role dimensions: personal factors, organizational factors, involvement with product decisions, and level of contact with interfaces. Significant relationships were found only for involvement with product decisions and level of contact on the job satisfaction dimension.
TL;DR: Excess enthalpies, excess volumes, and excess Gibbs free energies are reported over the entire composition range for n -hexane + di- n -butyl ether at 298.15 and 308.15 K.
TL;DR: The excess enthalpies of n -pentane + methanol, + ethanol, + n -propanol,+ n -butanol, + N -pentanol,+ N -hexanol, as discussed by the authors.
TL;DR: In this article, the potent antitumor benzo[c]phenanthridine alkaloids nitidine and fagaronine were synthesized as analogs of the potent antimalarial benzo [c] phenanthridines.
TL;DR: Dimethyl sulfate and its hydrolysis product monomethyl sulfate have been found at concentrations as high as 830 parts per million in fly ash and in airborne particulate matter from coal combustion processes, posing a new environmental problem.
Abstract: Dimethyl sulfate and its hydrolysis product monomethyl sulfate have been found at concentrations as high as 830 parts per million in fly ash and in airborne particulate matter from coal combustion processes. This discovery poses a new environmental problem because of the mutagenic and carcinogenic properties of these compounds.