Showing papers by "Pennsylvania State University published in 1968"

The Atom‐Probe Field Ion Microscope

Abstract: A serious limitation of the field ion microscope has been its inability to identify the chemical nature of the individually imaged atoms. The newly conceived atom‐probe FIM is a combination probe‐hole FIM and mass spectrometer having single particle sensitivity. During observation, the observer selects an atomic site of interest by placing it over a probe hole in the image screen. Pulsed field evaporation sends the chosen particle through the hole and into the spectrometer section. Preliminary results show that field evaporation of tungsten under poor vacuum conditions occurs as triply or quadruply charged WO, WN, WO2, and WN2 ions, while under better conditions doubly and possibly triply charged tungsten can be observed. Mo–Re alloys always produced doubly charged molybdenum and rhenium ions when examined in the atom‐probe. Wide applications for the study of short range order in alloys, the chemical nature of precipitates and impurity atoms, and information regarding the imaging properties of various atom species, of both the substrate and adsorbed material, are foreseen.

Asymptotic Similarity in Neutral Barotropic Planetary Boundary Layers

Abstract: New similarity expressions for turbulent Ekman layers have recently appeared, the theoretical foundation of which is analyzed in this paper. It is shown that the flow in Ekman layers has to be solved by singular perturbation methods. The similarity laws given by Gill and Csanady are, in first approximation, independent of the surface Rossby number if it is sufficiently large.

Pressure Dependence of the Elastic Constants of Single Crystalline Aluminum Oxide

Abstract: The six single crystal elastic constants of aluminum oxide have been measured by the ultrasonic pulse superposition method at 25 °C as a function of hydrostatic pressure up to 10 kbar. A linear pressure dependence has been found in all cases. The results are compared and found to agree approximately with theoretical data for the hexagonal close-packed structure with nearest neighbor central forces. They are also used to calculate the pressure dependence of the lattice parameters from Thurston's equation of state. The agreement with directly measured experimental data of Hart and Drickamer is excellent for one, and poor for the other lattice parameter. Die sechs elastischen Konstanten von Aluminiumoxyd-Einkristallen wurden bei 25 °C in Abhangigkeit vom hydrostatischen Druck mittels des Ultraschall-Impuls-Uberlagerungsverfahrens gemessen. In allen Fallen wurde eine lineare Druckabhangigkeit gefunden. Die Ergebnisse konnen angenahert durch die theoretischen Daten fur die hexagonal dichteste Kugelpackung mit Zentralkraften zwischen nachsten Nachbarn beschrieben werden. Sie werden auserdem dazu verwendet, mit Hilfe der Thurstonschen Zustandsgleichung die Druckabhangigkeit der Gitterparameter zu berechnen. Fur einen der beiden Gitterparameter ist die Ubereinstimmung mit direkt gemessenen Werten von Hart und Drickamer sehr gut, fur den anderen jedoch nur durftig.

Reticence: Pathology of the normal speaker

Abstract: (1968). Reticence: Pathology of the normal speaker. Speech Monographs: Vol. 35, No. 1, pp. 39-49.

Formation and stability of the platinum and rhodium oxides at high oxygen pressures and the structures of Pt3O4, β-PtO2 and RhO2

Abstract: The systems Pt-O and Rh-O have been investigated at high oxygen pressures (up to 3500 atm) and temperatures ranging from 400 ° to nearly 900 °C. Three platinum oxide phases were found: the hexagonal α-PtO2, already described in the literature, a new phase, β-PtO2 (CaCl2 structure), and Pt3O4 (NaxPt3O4 structure). β-PtO2 andPt3O4 are black, highly insoluble solids, which can be easily synthesized in bulk at high oxygen pressures. The tetragonal PtO phase reported by Moore and Pauling was not encountered in this study and neither was the b.c.c. Pt3O4 found by Galloni and Roffo . In the system Rh-O we found (besides the already-known, two Rh2O3 polymorphs) a new RhO2 phase with the rutile structure. RhO2 is a black, easily synthesized solid, which is highly insoluble even in hot aqua regia. “Goldschmidt radii” were derived for Pt4+ and Rh4+ and found to be 0.66 A and 0.64 A, respectively.

Recent spectra of atmospheric turbulence

Abstract: Spectra of atmospheric turbulence recently measured at various heights and sites under a variety of stability conditions have been analysed and compared. The results are: (i)In regions over which the spectra obey −5/3 power laws, the ratio of the lateral to the longitudinal spectra shows fair agreement with the 4/3 ratio predicted by the Kolmogorov hypothesis for the inertial sub-range. The vertical-longitudinal ratio has a similar tendency. (ii)Dissipation rates computed from the longitudinal spectra seem to be consistent with the hypothesis that dissipation is balanced by the total production of mechanical and convective turbulent energy, provided that the turbulence is in equilibrium. In transition from rough to smooth terrain, dissipation exceeds the other terms. (iii)Vertical-velocity spectra obey Monin-Obukhov similarity theory up to a height of about 50 m. Their shapes are reasonably uniform, the major change with stability being a change of scale of the wave number axis, i.e., any characteristic nondimensional wave number is a function of z/L only. This function appears to be the same as the relation between the normalized dissipation and z/L. These results are consistent with previously measured Kolmogorov constants and with measured ratios of standard deviation of vertical velocity to friction velocity. Up to about a height of 50 m the wavelengths of the maxima of the logarithmic spectra increase linearly with height and more slowly thereafter, up to about 300 m. The spectra in stable air above 50 m suggest the existence of a buoyant sub-range. (iv)Longitudinal spectra do not obey similarity theory in a number of ways. The wavelengths do not scale with height, and there may be differences between sites when the spectra are plotted in similarity coordinates. (v)Spectra over the sea seem to have relatively more energy at low frequencies than those over land.

Gadolinium Molybdate, a New Type of Ferroelectric Crystal

Abstract: Ferroelectric properties in gadolinium molybdate are shown to originate from a new mechanism completely different from that in conventional ferroelectric materials. In this crystal the spontaneous polarization results from an elastic instability which gives rise to a spontaneous strain in the original piezoelectric paraelectric phase. The dielectric permittivity of the clamped crystal ($\ensuremath{\epsilon}_{33}^{x}$) is low and independent of temperature, while the elastic constant ($c_{66}^{E}$) shows a strong temperature dependence with a marked anomaly at the Curie point.

Dating and physical attractiveness: Replication.

Abstract: Walster, et al. (1966) held a dance at the University of Minnesota at which 752 men and women were randomly paired to form 376 couples. Ss did not know their dates prior to contact at the dance. Although a number of hypotheses were made relating different measures to the desire for future dating, the only correlate with desire to date has been the partner's social desirability, operationally defined in the study as the parrner's rated physical attractiveness. The present smdy is n replication of Walster with several minor changes. The number of Ss, college freshmen and sophomores, is smaller; N = 58. Thus 29 couples, strangers before the dance, were randomly formed with the qualification that the boy be mller than the girl, as in the original scudy. The small N made the dance manageable and conceivably allowed Ss to interact with several other people present. Another measure of social desirability was gathered in addition co physical attractiveness: the parrner's \"sociability\" defined by the question, \"How sociable or outgoing does your date seem?\" Questions also asked about similarity of interests, animdes, religious orientation, values, and intelligence of date. All questions were answered on a 7-point scale. \"lnterescs\" was not an item on the Walster questionnaire. In addition, the question was asked, \"Is there anyone else here at the party who you would like to dare in the fumre. If so, whom?\" The questionnaire was administered to men and women in separate rooms 2 hr. after the dance started. The criterion measure was the question, \"Would you like to go out with your date in the future?\" Ss answered on a 7-point scale ranging from definitely to definitely not. The following Pearsonian correlation coefficients give the relationship between the predictors and \"desire to date\" criterion: physical attractiveness, s = .89; sociable, s = .60; similar interests, r = .64 (df = 56, p < .O1 in all cases). There were no differences between predictor and criterion for men and women. For both sexes the attractiveness-desire to date correlation was .89 (df = 27, p < .01). The question asking who else might be dated yielded 1 4 names, 13 of whom were rated as very attractive ( 6 or 7 on a 7-point scale) by the person's date and by two independent raters who acted as chaperones. Assuming that the names of 7 attractive people would have been obtained by chance, 13 people out of 14 is significant at the .O1 level by a binomial test. N o other correlates of desire to date were found. The findings strongly support the Walscer data, especially the high correlation between attractiveness and desire to date. This correlation also supports the notion that it is very rewarding to be with someone who is physically attractive.

Carbohydrate Synthesis in Maize

Abstract: Publisher Summary This chapter covers some of the gene mutations associated with carbohydrate changes in maize endosperm and presents some of the current evidence on the nature of carbohydrate metabolism, especially starch synthesis, in maize endosperm The genetic control of polysaccharide and starch synthesis in maize endosperm is amply evident from the discussions presented in the chapter The advantages of using mutant organisms for the clarification of metabolic pathways have been demonstrated repeatedly since the early pioneering work of Beadle and Tatum The large collection and quantities of singular and multiple mutant maize plants and endosperm cultures currently available and the interest of many researchers offer excellent prospects for significant and relatively large contributions to the detailed knowledge of the genetic control and biochemistry of starch and carbohydrate synthesis and the differentiation of maize endosperm within the very near future The interactions of multiple mutations on pathways of starch synthesis offer a promising refinement for analyzing the actual pathways involved Physical studies of the starch granules of the various strains underway provide an additional tool for evaluating the influence of particular mutations on the synthesis and deposition of starch These studies have led the research on carbohydrates in maize endosperm into the areas of enzyme characterization, localization of activity, and aspects of enzyme synthesis of polysaccharides in plants, including enzyme repression and activation

Absorption of pyrimidines, purines, and nucleosides by Li-, Na-, Mg-, and Ca-montmorillonite /clay-organic studies XII/.

Abstract: Purines, pyrimidines and nucleosides absorption by Li-, Na-, Mg- and Ca-montmorillonite in aqueous solutions over range pH 2-12 by cation exchange

Dynamic mechanical behavior of a polyimide

Abstract: The dynamic mechanical properties of a polyimide (poly-4,4′-oxydiphenylene pyromellitimide) were studied from about 4 to 800°K. at audio frequencies. A prominent relaxation associated with absorbed water content occurs near 230°K. Below 270°K., the modulus undergoes a corresponding increase in value with increasing water content. Above 550°K. the onset of a major relaxation process is observed in the modulus data, and a maximum in the internal friction is observed at about 675°K. Minor relaxation peaks are also noted throughout the temperature range. Relatively minor differences are noted in the mechanical relaxation spectra for the polyimide when treated (after drying) with dimethylformamide, dimethylacetamide, and dimethylsulfoxide, whereas the treatment with water after drying has a marked effect on the relaxation behavior. A reactor radiation dose of 3000 Mrad also causes only minor alterations in the dynamic mechanical spectra.

A Method of Estimating Vertical Eddy Transport in the Planetary Boundary Layer Using Characteristics of the Vertical Velocity Spectrum.

Abstract: The vertical eddy diffusivity coefficient K is hypothesized to depend upon the parameters that determine the energy spectrum of the vertical velocity fluctuations. Vertical velocity spectra from the lowest 320 m of the atmosphere are used to verify a relation among the rate of dissipation of eddy energy per unit mass, the standard deviation of the vertical velocity fluctuations, and the wavenumber of the peak of the energy spectrum of the vertical velocity fluctuations. Observations at Round Hill, Mass., and Cedar Hill, Tex., are employed to verify that the vertical eddy viscosity KM is proportional to the product of any two of the above parameters. However, the Richardson number must be included with these parameters in order to estimate the vertical eddy conductivity KH. In addition, it is shown that the wavenumber maximum of the vertical velocity spectrum and the nondimensional ratio σw/u* may be approximated at heights less than 320 m by empirical formulae.

The Management of Scientific Manpower

Abstract: Management control of professional employees such as engineers and scientists leads to a state of conflict in the business organization. To management, the control of human resources implies the limiting of individualistic behavior of subordinates in order to realize the objectives of the firm. In contrast, the industrial scientist, even as a subordinate in an organizational hierarchy, believes that control as applied to him should allow for autonomy and independence as attributes of professionalism in his work environment. In this paper we examine various approaches to managerial control---traditional, bureaucratic, cybernetic, and behavioral---and their application to the engineer-scientist as the carrier of professional values in the work culture. A successful manager in this environment must create a work climate without emphasis on formal mechanisms of control and direction. Recent research indicates that to this effect optimum supervisory behavior involves neither excessive direction nor autonomy but frequent interaction with industrial scientists as participants in decision making. We conclude that management of industrial scientists in relation to their professional values should take place within the networks of informal organizational relationships. It involves the application of normative managerial control based upon the exercise of self-imposed sanctions by the industrial scientists themselves, and of colleague authority by their managers relying on communication and information for compliance with organization's objectives and goals.