Showing papers by "Pennsylvania State University published in 1974"
TL;DR: In this paper, the chemical and stable isotope compositions of unpolluted ground waters in carbonate terranes are a function of the pH, PCO2, 13C content of the ground water recharge, the 13C contents of the carbonate rock, and the manner in which the rock is dissolved or precipitated.
663 citations
TL;DR: Porous microstructures, having potential for prosthetic applications, consisting of hydroxapatite and of whitlockite are prepared by employing exchange reactions at elevated temperatures and pressures to achieve optimum mechanical and physical properties for a particular application.
Abstract: WE have prepared porous microstructures, having potential for prosthetic applications, consisting of hydroxapatite and of whitlockite, by employing exchange reactions at elevated temperatures and pressures. Rather demanding specifications are to be met by biomaterials being considered for tooth or bone replacement. Porous solids have the advantage of allowing circulation of body fluids and of increasing the potential for firm attachment of body tissue1,2. Weber et al.3 successfully replicated the porous structure of echinoid skeletal material in epoxy resin and in sodium silicate; and White et al.4 achieved replication of the coral Porites structure with methacrylate, tin, Tichonium, and sintered Al2O3. This was the starting point for our attempts to reproduce such structures in the phosphatic material which is a major component of human teeth and bones, hydroxyapatite. Such a material, porous, inorganic and sterile (formed at high temperatures and pressures), should be highly compatible with body tissue, and when used as bone implants may become essentially integral with the bone. Furthermore, composites of such porous hydroxyapatite with other materials including metals4 may achieve optimum mechanical and physical properties for a particular application.
626 citations
TL;DR: It is shown that the most general mean-finishing-time problem for independent tasks is polynomial complete, and hence unlikely to admit of a non-enumerative solution.
Abstract: Sequencing to minimize mean finishing time (or mean time in system) is not only desirable to the user, but it also tends to minimize at each point in time the storage required to hold incomplete tasks. In this paper a deterministic model of independent tasks is introduced and new results are derived which extend and generalize the algorithms known for minimizing mean finishing time. In addition to presenting and analyzing new algorithms it is shown that the most general mean-finishing-time problem for independent tasks is polynomial complete, and hence unlikely to admit of a non-enumerative solution.
539 citations
TL;DR: In this article, a contingency approach is proposed, various measures are discussed, and the authors critically review one of the most important but least understood concepts in management -organizational climate.
Abstract: This paper critically reviews one of the most important but least understood concepts in management--organizational climate. A contingency approach is proposed, various measures are discussed, and ...
476 citations
TL;DR: X-ray diffraction, electron diffraction and Raman scattering measurements are presented for dehydrated amorphous ZrO2 in this article, showing that the material lacks sufficient crystallinity to diffract X rays.
Abstract: X-ray diffraction, electron diffraction, and Raman scattering measurements are presented for dehydrated amorphous ZrO2. Although the material lacks sufficient crystallinity to diffract X rays, electron diffraction patterns indicate a microcrystallinity with a grain size of 15 to 30 A. Raman spectra characteristic of the metastable tetragonal polymorph were obtained from these materials. Heating the amorphous materials induces recrystallization into first a metastable tetragonal phase and then the stable monoclinic phase.
334 citations
TL;DR: In this article, self-reward was added to self-recording, and substantial weight loss improvements were observed, however, these reductions did not prove to be either enduring or significant.
256 citations
TL;DR: A (k - 1)-fold Eulerian series expansion is given for II(1 - q(n))(-1), where the product runs over all positive integers n that are not congruent to 0,i or - i modulo 2k + 1.
Abstract: A (k - 1)-fold Eulerian series expansion is given for II(1 - qn)-1, where the product runs over all positive integers n that are not congruent to 0,i or - i modulo 2k + 1. The Rogers-Ramanujan identities are the cases k = i = 2 and k = i + 1 = 2.
235 citations
TL;DR: For example, job level, in instrumental or technological terms, and perceived deficiency in decision making have differential effects on work related attitudes and perceptions of desired influence or relative power.
Abstract: Job level, in instrumental or technological terms, and perceived deficiency in decision making have differential effects on work related attitudes and perceptions of desired influence or relative p...
225 citations
TL;DR: This paper investigates the problem of initializing operational hurricane models with several types of real data and finds a general dynamic initialization scheme that is suitable for diabatic, viscous models yields very promising results.
Abstract: This paper investigates the problem of initializing operational hurricane models with several types of real data. Imbalances in real data generate inertia-gravity waves with periods that vary strongly in different regions of the hurricane domain. The energy of these waves is removed by propagation out of the domain, by the horizontal diffusion process, and by the truncation errors associated with the Matsuno time-differencing scheme. Several initialization schemes are tested with a symmetric hurricane model. Random and bias errors superimposed on perfect data produce imbalances that lend to significant errors in short-range forecasts. A general dynamic initialization scheme that is suitable for diabatic, viscous models yields very promising results. The dynamic initialization technique is utilized in an effort to determine the types of data that will be most useful in initializing operational hurricane models. In general, observations are most useful near the center of the storm at low levels. Te...
203 citations
TL;DR: In this paper, Euler and the Zeta Function were discussed. But they did not consider the Euler-Zeta function. And the Zetal Function was not considered.
Abstract: (1974) Euler and the Zeta Function The American Mathematical Monthly: Vol 81, No 10, pp 1067-1086
201 citations
TL;DR: It is concluded that the biplane angiographic method provides a practical, accurate means of quantitating RVV characteristics, including the magnitude of volume overload as well as the level of RV myocardial performance.
Abstract: Although the feasibility of angiographic estimation of right ventricular (RV) volume (V) has been demonstrated, no method has been validated by comparison with independent measurements of volume, and none has been applied to the systematic analysis of RVV characteristics in man. In the present study, postmortem casts of the human RV were used to determine a regression analysis for RVV for biplane frontal and lateral films by the Simpson's rule technique (true volume = 0.749 calculated volume, r = 0.99, see 3.7 ml, for casts ranging in volume from 20 to 115 ml). This method was then employed to estimate RVV from biplane cineangiograms of 32 patients. The validity of RVV measurements in vivo was corroborated by close correlation of stroke volumes estimated independently by angiographic and indicator dilution methods (r = 0.98, see 4.1 ml). In nine patients with normal RV hemodynamics RV end-diastolic volume (EDV) averaged 81 ml/m2 (range 63 to 101 ml/m2); ejection fraction (EF) averaged 0.51 (range 0.40 to ...
TL;DR: In this paper, the authors investigated the effect of covert modeling in reducing snake avoidance and found that the greatest vicarious learning tended to occur in subjects who imagined a model similar in fear-related and non-fear-related dimensions.
TL;DR: In this article, the negative logarithm of the dissociation constant of the CaHCO 3+ ion pair, p K ( CaCO 3 + ), is computed from conductance measurements.
TL;DR: In this article, the size and spacing of cumulus clouds are determined by the numerical integration of a compressible set of hydrodynamic equations for an atmosphere with saturation processes and cloud microphysics included.
Abstract: Factors controlling the size and spacing of cumulus clouds are determined by the numerical integration of a compressible set of hydrodynamic equations for an atmosphere with saturation processes and cloud microphysics included. Sets of integrations, each carried out for several hours of cloud simulation, produce fields of numerical clouds that pass through various stages of development. The characteristics of clouds in the initiation, growth, and fully-developed stages are examined. In addition, the development of group structures and cloud merging are also found. Comparison of numerical results with a variety of observations shows that the model gives realistic cloud characteristics.
TL;DR: Levels of adaptation to particular environmental dimensions are shown to act as potent determiners of the individual's evaluation of his environment, as well as representing a plausible basis for the optimal level of stimulation principle itself.
Abstract: This paper examines the environment as a source of dimensions of stimulation that are directly related to the individual's affective response to his environment, and his behavioral adaptation to it. The concept of an optimal level of stimulation is introduced, along with a view of environmental stress as resulting from conditions of excessive deviation from such optimal levels, with particular reference to variations in intensity, diversity, and patterning of the stimulus input. This analysis provides the framework for a consideration of behavioral adaptation to the environment by reference to the concept of adaptation level. Levels of adaptation to particular environmental dimensions, established as a function of past exposure, are shown to act as potent determiners of the individual's evaluation of his environment, as well as representing a plausible basis for the optimal level of stimulation principle itself. The presentation proceeds to an examination of the process of adaptation to the environment as a multilayered process, and to a discussion of the concept of the cost of adaptation as it applies in the behavioral realm. Finally, adaptation is contrasted with an alternative mechanism, adjustment, involving active alteration of the environment by the individual, and the relative place to be accorded to these two processes in the individual's relation to the environment is considered.
TL;DR: The protoplasmic viscosity was studied using a small spin label having high permeability and broad solubility properties and nickel chloride as an extracellular spin-subtracting agent to localize signal inside cells, suggesting that lateral diffusion in biological membranes is important to cell function.
Abstract: The protoplasmic viscosity was studied by using a small spin label having high permeability and broad solubility properties and nickel chloride as an extracellular spin-subtracting agent to localize signal inside cells. The viscosity is variable and in some cells is many times that of water or phospholipids, suggesting that lateral diffusion in biological membranes is important to cell function.
TL;DR: In this paper, the authors explain the lack of equilibrium between dissolved and reactive O2 and the presence of ionic Mn species on seafloor sediments by using surface adsorption and cation substitution within disordered birnessite-todorokite structure.
TL;DR: Bounding techniques similar to those used with branch and bound procedures are used in this study in conjunction with zero-one programming to produce minimum duration schedules for the resource constrained, project scheduling problem.
Abstract: Bounding techniques similar to those used with branch and bound procedures are used in this study in conjunction with zero-one programming to produce minimum duration schedules for the resource constrained, project scheduling problem. The algorithms developed consist of examining the feasibility of a series of zero-one programming problems rather than solving one zero-one problem optimally. Computational results demonstrate the advantage of this method over using zero-one programming without employing any form of bounding. A comparison with other exact procedures for solving the resource constrained, project scheduling problem is also given.
TL;DR: Rats with lesions to the medial or orbital aspects of the prefrontal cortex differed from one another as the rats with orbital lesions exhibited consistently low contact scores and the Rats with medial lesions did not, while both groups showed increased levels of shock induced aggression.
TL;DR: Autoradiography with tritiated acetazolamide indicates that osteoclasts of the hen and chick contain concentrations of carbonic anhydrase which are similar to those in pancreatic acinar cells, which seems to be of physiological importance in bone resorption.
Abstract: Autoradiography with tritiated acetazolamide indicates that osteoclasts of the hen and chick contain concentrations of carbonic anhydrase which are similar to those in pancreatic acinar cells. Grain counts of osteoblasts and osteocytes were not different from background. Thus, a sufficient quantity of carbonic anhydrase seems to be present in osteoclasts to be of physiological importance in bone resorption.
TL;DR: Complete adrenal suppression for as long as 19 months was observed, with objective tumor regression in eight subjects and relief of bone pain in three others without producing cushingoid side effects.
Abstract: We used amino-glutethimide and dexamethasone in patients with carcinoma of the breast to abolish adrenal steroidogenesis. Initial studies with this approach, however, did not result in complete adrenal suppression and suggested the possibility of accelerated dexamethasone metabolism. The observation of a twofold reduction in H dexamethasone half-life during amino-glutethimide therapy confirmed this hypothesis. Larger doses of dexamethasone (1.5 to 3.0 mg/day) were administered to 22 patients receiving 1 to 2 gm of amino-glutethimide daily to compensate for rapid dexamethasone metabolism. Complete adrenal suppression for as long as 19 months was then observed, with objective tumor regression in eight subjects and relief of bone pain in three others without producing cushingoid side effects. ( JAMA 230:1661-1665, 1974)
TL;DR: Comparisons within bulls for pairs of measurements revealed no significant difference in the number of sperm recovered from the rete testis, from the cauda epididymidis, or representing one-half of those ejaculated daily before surgery.
TL;DR: The report attempts to show that many technical skills in chimpanzee technical skills are and probably were firmly rooted in Primate prehistory, well before the advent of the earliest hominids.
TL;DR: In this article, Monte Carlo methods were employed to contrast several procedures with respect to a.) control over Type I errors and b.) power. And they indicated that the generalized Welch technique may be substituted for the AOV when variances are heterogeneous and n's are unequal.
Abstract: Numerous studies have documented the robustness of t and F to heterogeneous variances under the restricted condition of equal n’s. Likewise, the distortion of α in the presence of unequal n’s and variances has been demonstrated in both mathematical and empirical studies. Several investigations, however, have shown the Welch technique to be robust to this disturbing situation in the two group case. The present study was addressed to the k group AOV situation. Monte Carlo methods were employed to contrast several procedures with respect to a.) control over Type I errors and b.) power. Results indicate that the generalized Welch technique may be substituted for the AOV when variances are heterogeneous and n’s are unequal.
TL;DR: This paper looks at the inventory-related models published during the last ten years from the systems point of view, and a synthesized review of recently published models belonging to each individual category is presented.
Abstract: This paper looks at the inventory-related models published during the last ten years from the systems point of view. A chart is given to show the broad oategories of inventory models. The paper first lists eleven quantifiable and four non-quantifiable variables (and their types) that go into inventory formulas, affect inventory decisions, and have already been identified by the researchers. Next, various research papers are grouped in six oategories based on similarities of approaches UBed by these papers. These categories are : (1) models for determining optimum inventory polioies, (2) lot size optimization, (3) optimization of various specific: management objectives, (4) models for optimizing highly specialized inventory situations, (5) application of advanced mathematical theories to inventory problems, and (6) models bridging the gap between theory and practice. Next a synthesized review of recently published models belonging to each individual category is presented, and salient features of individual...
TL;DR: Diagnostic-prescriptive teaching is an attempt to identify the most effective instructional strategies for children who differ on any number of variables believed to be related to academic learning as mentioned in this paper.
Abstract: Diagnostic-prescriptive teaching is an attempt to identify the most effective instructional strategies for children who differ on any number of variables believed to be related to academic learning. Educators and psychologists believe that some children learn best under one' instructional strategy (particular materials, teaching techniques, methods of content presentation, and reinforcers) while other children learn best when another instructional strategy is employed (see, for example, Bracht, 1970; Cronbach, 1957; Reynolds & Balow, 1972). Noted educators recently have called for prescriptive teaching of handicapped children based on the results of educational and psychological testing. The steps 10 diagnostic-prescriptive teaching include identification of children who are experiencing learning difficulties, diagnostic delineation of learner strengths and weaknesses, and prescriptive intervention (specification of goals, methods, strategies, materials, etc.) in light of these strengths and weaknesses. Effective diagnostic-prescriptive teaching rests on four critical assumptions:
Journal Article•
TL;DR: The ineffectiveness of hypnotic drugs demonstrated in this study and in earlier sleep laboratory drug evaluation studies indicates the need for changes in the guidelines used for evaluating and advertising hypnoticdrugs.
Abstract: Ten patients, each of whom had been using hypnotic drugs for periods ranging from months to years, were monitored in the sleep laboratory while continuing to receive medication. Comparison with insomniac controls who were not receiving medication demonstrated a significant decrease of rapid eye movement (REM) sleep in the chronic drug users. A striking finding was the fact that all of these patients had as great or greater difficulty in falling asleep or staying asleep, or both, than the insomniac controls who were not using medication. Abrupt withdrawal of ineffective drugs is not recommended due to psychological and physiological changes that contribute to drug-withdrawal insomnia and hypnotic-drug dependence. The ineffectiveness of hypnotic drugs demonstrated in this study and in our earlier sleep laboratory drug evaluation studies indicates the need for changes in the guidelines used for evaluating and advertising hypnotic drugs.