Showing papers by "Stevens Institute of Technology published in 1979"
73 citations
TL;DR: In this paper, the ground and excited states of Au2 were studied using ab initio averaged relativistic effective core potentials (AREP) and MCSCF-CI procedures.
Abstract: The ground and excited states of Au2 are studied using ab initio averaged relativistic effective core potentials (AREP) and MCSCF–CI procedures Spin–orbit effects are included in the excited states derived from 2S1/2+2D3/2 and 2S1/2+2D5/2 atomic states using an empirical procedure The ground state dissociation energy is calculated to be 227 eV as compared to the experimental value of 231 eV The calculated energies for the two spectroscopically allowed 0+g to 0+u transitions and other molecular parameters also agree reasonably well with experiment
68 citations
TL;DR: In this article, the ground 1 Σ+g(0+g) state of Au2 using a variety of ab initio effective core potentials (EPs) was investigated.
Abstract: SCF calculations have been carried out for the ground 1Σ+g(0+g) state of Au2 using a variety of ab initio effective core potentials (EP). The effective core potentials studied both include a two‐component relativistic EP (REP) that includes spin–orbit effects and also averaged relativistic EP (AREP) and a nonrelativistic EP (NREP). All‐electron nonrelativistic calculations were also performed. The values of spectroscopic constants obtained from these calculations indicate that relativistic effects account for a decrease in Re of over 0.3 A and an increase in the bond energy of the order of 1 eV. Various intercomparisons indicate the general validity of effective potential methods, properly applied, but also show certain limitations. In particular, the NREP results agree well with the all‐electron, nonrelativistic calculations. Also, various relativistic effective‐potential methods agree for SCF calculations provided both the basis sets and the EP are carried to sufficiently high order in angular quantum n...
62 citations
TL;DR: In this paper, a series of levan fractions, the products of partial acid hydrolysis of Streptoccoccus salivarius levan, were examined for changes in relative degree of branching.
57 citations
TL;DR: Graphical techniques are presented for estimating Hough transform performance for detecting straight lines in noisy digital pictures showing explicitly the influence of noise due, for example, to quantizing errors on the accuracy of estimating the underlying sets of collinear points.
Abstract: Graphical techniques are presented for estimating Hough transform performance for detecting straight lines in noisy digital pictures. The methods show explicitly the influence of noise due, for example, to quantizing errors on the accuracy of estimating the underlying sets of collinear points. Exact bounds are obtained for sets of collinear points showing that under quite general conditions only the endpoints are of significance. Theorems governing grid size for the accumulator method are given.
47 citations
TL;DR: Several quinazoline derivatives incorporating a trans-stillbene moiety were synthesized as potential post-coital antifertility agents but some of these compunds showed low level activity in rats.
39 citations
TL;DR: In this article, the authors investigated the validity of the male managerial stereotype and found that high achievement, high dominance, and low nurturance support the stereotype, since these traits appear to be associated with both males and females who have attained a managerial position.
27 citations
TL;DR: In this article, the assignment of chemical shifts for all the C atoms has been achieved by using techniques recently reported by Bose et al. They also examined the C NMR spectra of some naturally occurring furocoumarins and derivatives.
24 citations
TL;DR: In this paper, two methods, Reich-Stivala (R-S) and double-log (D-L), were employed to distinguish one mechanism from among 15 theoretical possibilities for heterogeneous solid-state reactions using theoretical TG data.
24 citations
24 citations
TL;DR: In this paper, the authors reformulate the postman problem as the problem of finding the minimum number of copies of lines from a graph that have to be added to obtain an eulerian spanning supergraph.
Abstract: Of course most connected graphs have some odd-degree points so that in many cases it is impossible to traverse the lines, each one exactly once, and return to the starting point. In 1962 Mei-ko [6] posed the problem of finding a shortest closed covering walk, i.e., a closed walk including all the lines of a connected graph G. Because he originally formulated the problem in terms of the shortest distance a postman must walk to complete his tour, the problem is usually referred to as the “Chinese Postman Problem.” A myriad of variations exist including applications t o garbage collection, security patrolling, and rail-line inspection. Several authors including Mei-ko [6], Edmonds and Johnson [2], and Goodman and Hedetniemi [4] have solved the problem using somewhat different approaches. Mei-ko characterized the minimum closed covering walks in terms of a cycle property they possess. Edmonds and Johnson used matching theory and obtained a sophisticated algorithm for determining the minimum-length tour, while Goodman and Hedetniemi facilitated the solution with the aid of a “minimum pairing” of the odd-degree points of the graph-a notion we shall discuss later. So that we can easily pose the problems that interest us let us first reformulate the postman problem. Suppose W: uo, xl, u l r x2, u2 , ..., u ” . ~ , x,,, u,, = uo is a closed covering walk of a graph G. For each repetition of a line xi in W add a copy of xi to G. The resulting multigraph is clearly eulerian. Thus another way to pose the postman problem is to ask for the minimum number of copies of lines from G that have to be added t o G t o obtain an eulerian multigraph. Other questions concerned with the addition of lines to a given graph, multigraph, or pseudograph t o produce eulerian super structures arise quite naturally. We shall consider the following problems in the sequeI: (1) Given a (possibly disconnected) multigraph, when is it possible to obtain an eulerian spanning supermultigraph by the addition of lines and what is the minimum number of required lines? (2) Given a (possibly disconnected) graph, when is it possible to obtain an eulerian spanning supergraph by the addition of lines (necessarily from the complement of the graph) and what is the minimum number of required lines?
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TL;DR: The requirements for such a data base system are described, the "network" data base schema is developed and the schema and command language are illustrated through a specific example.
Abstract: This paper develops the design of a data base system to support operations research models in the context of an integrated planning system involving a number of different users and computer programs. The requirements for such a system are described, "network" data base schema is developed and the schema and command language are illustrated through a specific example.
TL;DR: A random Petri net model is presented and analyzed that has application to systems involving concurrency and is suitable for solving the problem of distributed systems.
Abstract: A random Petri net model is presented and analyzed. The model has application to systems involving concurrency.
TL;DR: The reaction of a Schiff base derived from veratrylamine and cinnamaldehyde with (α-methyl-β-alkoxycarbonyl)-vinylamino acetic acid (from glycine and an acetoacetate ester) in presence of a chloroformate esters and triethylamine constitutes a safe synthesis of α-vinyamino β-lactams that can be converted by literature methods to known intermediates for the synthesis of isocephalosporins and analogs.
TL;DR: In this article, the early years of the scientific periodical Observations sur la physique, sur l'histoire naturelle et sur les arts (1771-1823, Paris), or "Rozier's Journal" after Francois Rozier (1734-1793), are examined.
Abstract: Summary This paper examines the early years of the eighteenth-century scientific periodical Observations sur la physique, sur l'histoire naturelle et sur les arts (1771–1823, Paris), or ‘Rozier's Journal’, after Francois Rozier (1734–1793). Rozier's Journal is seen as a transitional and competing genre for scientific publication directed at shortcomings in the learned society press and in contemporary scientific communications. The evolution of this role is traced as the Journal emerged from the independent press between 1771 and 1773. It is argued that Rozier's Journal, limited to the sciences physiques (physical sciences), marked only a step towards the specialized periodical of the nineteenth century. The professional character of Rozier's intended audience is suggested, and Rozier's unexpectedly close ties to the scientific societies are explored. The Journal is seen to be part of both the old and the new, a unique case in the ancien regime press.
TL;DR: In this article, the structure of evaporated thin gold films subjected to high d.c. density stressing (approximately 2 × 10 6 A cm −2 for 1000 h) was studied using a transmission electron microscope.
TL;DR: For two classes of schemes defined by a graph theoretic property, an equivalent algebraic characterization is found.
TL;DR: On the basis of its mass spectrum, nmr and hydrolysis products, the iridoid glucoside paederoside, is identified as an S-methyl thiocarbonate as mentioned in this paper.
TL;DR: In this paper, the authors extended existing hydrodynamic theory for ship resistance added by waves to include time-dependent fluctuations, so that the so-called "quadratic frequency response function" for added resistance could be computed and compared with previously obtained experimental estimates.
Abstract: The objective of the present work was to extend existing hydrodynamic theory for ship resistance added by waves to include time-dependent fluctuations, so that the so-called "quadratic frequency response function" for added resistance could be computed and compared with previously obtained experimental estimates. The concept of a quadratic frequency response function follows from the (nonphysical) theory for the general functional polynomial input-output model which was utilized in the previous experimental work. It was hoped that the present work, by providing a physical model, would either lend credibility to the previous work or expose its shortcomings. In the event, the present work appears to have accomplished both. Analytical and experimental estimates of the quadratic frequency response function are in good qualitative agreement, and in fair quantitative agreement. Most of those experimental estimates which appeared in the previous work to be of at least slightly dubious statistical merit have been discredited. Since it was these marginal experimental estimates which gave rise to the speculation that the quadratic frequency response function was inordinately complicated, the present work indicates that the function is merely moderately complicated. There seems reasonable evidence that it is feasible to make hydrodynamic estimates of the quadratic frequency response function required for prediction of nonlinear fluctuations of resistance in random seas.
TL;DR: In this paper, a series of heterocyclic analogs of diarylethylene and triary lethylene were synthesized as potential anti-implantation agents and tested in rats as oral, post-coital antifertilily agents.
TL;DR: In this article, material and energy balances describing nonisothermal copolymerizations were developed which are similar in form to those describing non-isothermal homopolymerizations. But these balances are based on the same theory as the ones described in this paper.
Abstract: Thermal ignition theory has been extended to include free-radical copolymerizations resulting in dimensionless criteria for runaway and ignition. These criteria were verified by computer simulation and preliminary experimentation. Approximate, but greatly simplified, material and energy balances describing nonisothermal copolymerizations were developed which are similar in form to those describing nonisothermal homopolymerizations. Regions of close agreement, as well as disagreement, between conversion and temperature histories from these approximations and those from the exact balances are described.
TL;DR: In this article, a theoretical approach is developed and a computational procedure adaptable to a high speed digital computer is established for the evaluation of the blade pressure distribution of a marine propeller due to thickness and loading effects.
Abstract: : A theoretical approach is developed and a computational procedure adaptable to a high speed digital computer is established for the evaluation of the blade pressure distribution of a marine propeller due to thickness and loading effects The dual role of the blade thickness is considered The contribution of the nonplanar thickness to the propeller loading and pressure distribution and the effect of the flow distortion thickness are studied by means of the thin body approximation The surface integral equation which relates the unknown loading to the known velocity distribution on the blades is solved by the mode approach in conjunction with the lift operator technique The analysis treats both design and off-design conditions in steady-state and unsteady flows, and the proper chordwise modes are selected for each condition The numerical solution yields the blade loading and resulting hydrodynamic forces and moments and blade bending moments, and, in addition, the blade pressure distributions on each blade face due to both loading and thickness effects, thus providing information necessary for the prediction of cavitation inception Calculations have been performed for a set of three 3-bladed propellers of different EAR operating in a screen-generated wake, for comparison with experimental data
TL;DR: It is shown that for every pair of integers m > n > 1 there is a graph of point connectivity n whose line graph has point connectivity m.
Abstract: Chartrand and Stewart have shown that the line graph of an n-connected graph is itself n-connected. This paper shows that for every pair of integers m > n > 1 there is a graph of point connectivity n whose line graph has point connectivity m. The corresponding question for line connectivity is also resolved.
TL;DR: In this article, the carbon-13 NMR spectra of a variety of mono-and bicyclic β-lactams have been measured and the chemical shifts of the ring carbon atoms have been assigned unambiguously.
Abstract: Carbon-13 NMR spectra of a variety of mono- and bicyclic β-lactams have been measured and the chemical shifts of the ring carbon atoms have been assigned unambiguously. Effects of substituents on the chemical shifts of these carbons are also discussed.
TL;DR: In this article, the Coefficient of Performance (COP) and Specific Heating Effect (SHE) of the regenerated and unregenerated cycles are computed and optimized using only heating data.
Abstract: Using reasonable assumptions for turbomachinery efficiencies and heat exchanger effectivenesses, the Coefficient of Performance (COP) and Specific Heating Effect (SHE) of the regenerated and unregenerated cycles are computed and optimized. Only heating data are presented and both open and closed cycles are considered. An effort is made to indicate those cases where (the working fluid being air) the cycle may be appropriately open to combine the heating function with ventilation. When driven by an appropriately small direct Brayton cycle prime mover, the total potential for a new and widespread gas turbine application of literally millions of units becomes defined.
TL;DR: In this article, it was shown that the momentum transfer from an electromagnetic or electrostatic wave to an electron is comparable to the one obtained from the ponderomotive force in the presence of friction.
TL;DR: In this paper, free-radical copolymerizations were studied under nonisothermal conditions with emphasis on their thermal runaway and ignition behavior, and a new method was proposed for the evaluation of runaway parameters from scant kinetic data.
Abstract: Free-radical copolymerizations were studied under nonisothermal conditions with emphasis on their thermal runaway and ignition behavior. Computational models are presented in generalized form and compared with experiments on the system styrene-acrylonitrile. A new, useful method is proposed for the evaluation of runaway parameters from scant kinetic data.