bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and Information Services at Lied Library
Authors: Nozero Victoria , Finley Priscilla
Published: March 2005

Purpose

This paper summarizes the changes in the organization and services of the Research and Information Department since moving into Lied Library.

Design/methodology/approach

Includes a description of reorganization and strategic planning efforts of the department, along with possible future direction for the evolution of services, space utilization and staffing.

Findings

The reality of living in the new facility, Lied Library, proved to require changes not envisioned during the planning phase. Lied Library is not a static environment. Allocation of space and the way services are provided to customers continue to evolve.

Originality/value

This paper will be helpful to others planning a new academic library, and highlights the need for ongoing planning and evaluation of services after the building project is completed. It also describes successful and less successful strategic planning efforts for an academic reference department.
Branch libraries and technology: impact of a new main library
Authors: Brown Jeanne M. , Fabbi Jennifer L. , Taranto Cheryl
Published: March 2005

Purpose

To explore the interactions between branch libraries and a new main library, in the area of technology equipment and services.

Design/methodology/approach

Following an introduction which highlights the major elements in place at UNLV Libraries for networking and equipment, each branch situation is described and evaluated.

Findings

The advantages of UNLV Libraries' philosophical approach to consistent patron access at all points of service are found to be substantial, and include regular equipment and software upgrades, as well as systems expertise. The major disadvantage proves to be flexibility in approaching patron needs.

Practical implications

Provides a philosophical basis and concrete examples of branch efforts to provide adequate technology and services to their patrons.

Originality/value

Useful to branch librarians making a case for enhanced resources, or discussing possible configurations of responsibility regarding technology equipment and services.
Local online information systems in Jordanian university libraries
Authors: Razeq Mustafa Younis Abdul
Published: March 2005

Purpose

The study is concerned with gathering factual data on the use of local online information systems, automation, online connections, online public access catalogs (OPACs), CD‐ROM‐based systems in 19 Jordanian university libraries.

Design/methodology/approach

Information was sought through a written questionnaire; personal interviews; literature review, and field visits. The implementation of local online information systems; OPACs, CD‐ROM databases, online searching, networks/databases subscribed to, methods of online services to users, problems and solutions are investigated.

Findings

Of the 18 (94.7 percent) libraries responded, half (50 percent) are using MINISIS or CDS/ISIS, one‐third (33.3 percent) is using either M2L, or ORACLE based systems, and 3 (16.7 percent) are using locally designed packages. Technical processing, information retrieval, circulation, reference services, and serial control are the prime systems functions. All respondents are linked to the internet. A total of 15 (83.3 percent) respondents have developed collections of databases on CD‐ROMs; 11 (73.3 percent) use single‐ access, and four (26.7 percent) use multi‐user systems.

Practical implications

Online services are provided mostly by traditional means. Lack of skilled staff, shortages of fund, and insufficient hardware are prime obstacles hindering systems optimal utilization. Outdated databases, cost, and users incompetence are problems limiting the optimal use of online systems. Developing intranet, funding, trained manpower, training courses to users, sharing subscription expenses in electronic full‐text database, and promote cooperation to exchange OPACs records through the internet, are suggested solutions to overcome these problems.

Originality/value

Academic libraries in Jordan are changing emphasis from ownership of information sources in printed forms, to the access to online databases or local area networks systems based on CD‐ROMs, to linkage with the internet as a prime gateway to information sources.
Triplophysa rosa sp. nov.: a new blind loach from China
Authors: Chen X. Y. , Yang J. X.
Published: March 2005

A new blind loach of Triplophysa Rendahl 1933 was collected from a subterranean pool in a cave at Wulong County, Chongqing City, China, in November 2002. The new species, named Triplophysa rosa sp. nov., can be distinguished from its congeners by the following unique characters: eyes vestigial; 9 branched dorsal‐fin rays; 12 branched pectoral‐fin rays; 7 branched pelvic‐fin rays; 6 branched anal‐fin rays; 7 + 7 branched caudal‐fin rays; distal margin of dorsal‐fin concave; tip of pelvic‐fin surpasses vertical level of anus; caudal‐fin deeply forked; whole body scaleless and colourless.
Mediterranean fruit fly (Dipt., Tephritidae) suppression in persimmon through bait sprays in adjacent coffee plantings*
Authors: McQuate G. T. , Sylva C. D. , Jang E. B.
Published: March 2005

Abstract:  Oriental persimmon, Diospyros kaki L., in Upper Kula on the island of Maui (Hawaii) is attacked by the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Recent suppression trials using mass trapping with a synthetic food‐based bait, initiated in alternate host crops before the start of persimmon season, had shown promise as a means of reducing C. capitata population levels. However, this did not adequately suppress C. capitata population where there were adjacent plantings of coffee, Coffea arabica L., a favoured alternate host, which bears fruits before and during the persimmon season. To improve C. capitata population suppression, we applied a spinosad‐based bait spray to coffee plants, starting before persimmon fruits became susceptible to oviposition by the Mediterranean fruit fly. The bait spray suppressed the C. capitata population and led to reduced infestation of both coffee cherries and persimmon fruits. Percentage parasitization of C. capitata in coffee cherries by established biological control agents, primarily Fopius arisanus (Sonan), was not significantly different in unsprayed vs. sprayed plots even after 11 weekly sprays. These results suggest that mass trapping, combined with spinosad‐based bait sprays, are control components that are compatible with biological control and can be combined in an integrated pest management system for C. capitata.
Elicitation of Ethylene by Verticillium albo‐atrum Phytotoxins in Potato
Authors: Mansoori B. , Smith C. J.
Published: March 2005

Petioles from a susceptible cultivar (Désirèe) of Solanum tuberosum treated with a low‐molecular mass toxin, separated from culture fluid of Verticillium albo‐atrum, produced greater quantities of ethylene than did petioles of a tolerant cultivar (Home Guard). Pretreatment of leaflets from cv. Désirèe with silver thiosulphite, which inhibits perception of ethylene, prevented the chlorosis and necrosis normally associated with exposure to the toxin. Similarly, application of aminoethoxyvinylglycine (AVG) an inhibitor of aminocyclopropane‐1‐carboxylic acid (ACC) synthase, to petioles of cv. Désirèe reduced toxin‐induced ethylene synthesis and symptom development. The data indicate that, in part, Verticillium‐toxin acts through induction of ethylene biosynthesis in the host tissues, and different responses of susceptible and tolerant potato cultivars to V. albo‐atrum are the result of differential production of ethylene.
Corneal vascularization in the Florida manatee (Trichechus manatus latirostris) and three‐dimensional reconstruction of vessels
Authors: Harper Jennifer Y. , Samuelson Don A. , Reep Roger L.
Published: March 2005

The cornea of the Florida manatee is unique and unusual in its anatomy in that blood vessels have been found throughout. In all other animal species, this is considered a pathological condition impeding vision, and is usually caused by injury or trauma. The purpose of this study was to more clearly describe corneal vascularization by examining the architecture through three‐dimensional reconstruction in order to find possible patterns in size, distribution, and location of blood vessels relative to gender, age, location, and season. Twenty‐six eyes from 22 individuals were prepared for histologic examination and subsequent three‐dimensional reconstruction. Every specimen examined had blood vessels in the cornea, comprising an average of 0.3% of total surface density (volume) of the cornea. No differences were found between individuals based on gender, age, and season. Environmental influences were not a significant factor either, which was not originally anticipated. The presence of vessels at the level of the anterior epithelium was surprising and it appeared that the vascularization was directed more anteriorly than was originally thought. The presence of blood vessels in a prenatal eye was also found. In all the eyes examined, no signs of injury or trauma could be observed. The presence of blood vessels appears to minimally impair vision based on their low density, size, and location. The association of vessels with the anterior epithelium and development of vessels within the fetus point to an evolutionary adaptation possibly due to the manatee's unique ability to move between water bodies.
Ahmed valve implantation to control intractable glaucoma after phacoemulsification and intraocular lens implantation in a dog
Authors: García‐Sánchez Gustavo Adolfo , Whitley R. David , Brooks Dennis E. , Trigo Francisco , Piñón Aytzeé
Published: March 2005

An 11‐year‐old spayed female Miniature Poodle presented with bilateral senile cataracts. Treatment was cataract removal by phacoemulsification and intraocular lens implantation. Five hours after surgery the operated right eye was partially closed and painful. The right pupil was fully dilated, there was generalized corneal edema, and intraocular pressure (IOP) was increased. After 12 h of medication IOP was controlled. Ten weeks after surgery the owners reported cloudiness of right eye, and the dog was again evaluated. The IOP was again increased and an Ahmed valve was implanted. This case describes describe the progression of this case and benefits of controlling postcataract surgery glaucoma by the implantation of an Ahmed valve.
Simulating Pulsatile Flows Through a Pipe Orifice by an Immersed-Boundary Method
Authors: Yakhot Alexander , Grinberg Leopold , Nikitin Nikolay
Published: March 2005

A pulsatile laminar flow of a viscous, incompressible fluid through a pipe with a sudden constriction (an orifice) was simulated by an immersed-boundary method. A fluid is forced to move by an imposed sinusoidally varying pressure difference, Δpt. For a pulsatile flow through a pipe orifice, an oscillating recirculation bubble develops behind the orifice. The induced flow rate, Qt, the recirculation bubble length, Lbt, as well as their phase shift ϕQ,ϕL with respect to the imposed pressure difference were computed for different constriction ratios and the Womersley Ws number.
Modeling of Complex Manufacturing Processes by Hierarchical Fuzzy Basis Function Networks With Application to Grinding Processes
Authors: Lee Cheol W. , Shin Yung C.
Published: March 2005

A framework for modeling complex manufacturing processes using fuzzy neural networks is presented with a novel training algorithm. In this study, a hierarchical structure that consists of fuzzy basis function networks (FBFN) is proposed to construct comprehensive models of the complex processes. A new adaptive least-squares (ALS) algorithm, based on the least-squares method and genetic algorithm (GA), is proposed for autonomous learning and construction of FBFNs without any human intervention. Simulation studies are performed to demonstrate advantages of the proposed modeling framework with the training algorithm in modeling complex manufacturing processes. The proposed method is implemented for the surface grinding processes based on the hierarchical structure of FBFNs. Process models for surface roughness and residual stress are developed based on the available grinding model structures with a small number of experimental data to demonstrate the concept. The accuracy of developed models is validated through independent sets of grinding experiments.
Control of Uncertain LTI Systems Based on an Uncertainty and Disturbance Estimator
Authors: Zhong Qing-Chang , Rees David
Published: March 2005

This paper proposes a robust control strategy for uncertain LTI systems. The strategy is based on an uncertainty and disturbance estimator (UDE). It brings similar performance as the time-delay control (TDC). The advantages over TDC are: (i) no delay is introduced into the system; (ii) there are no oscillations in the control signal; and (iii) there is no need of measuring the derivatives of the state vector. The robust stability of LTI-SISO systems is analyzed, and simulations are given to show the effectiveness of the UDE-based control with a comparison made with TDC.
Analysis of Friction-Induced Limit Cycling in an Experimental Drill-String System
Authors: Mihajlovic´ N. , van Veggel A. A. , van de Wouw N. , Nijmeijer H.
Published: March 2005

In this paper, we aim for an improved understanding of the causes for torsional vibrations that appear in rotary drilling systems used for the exploration of oil and gas. For this purpose, an experimental drill-string setup is considered. In that system, torsional vibrations with and without stick-slip are observed in steady state. In order to obtain a predictive model, a discontinuous static friction model is proposed. The steady-state behavior of the drill-string system is analyzed both numerically and experimentally. A comparison of numerical and experimental bifurcation diagrams indicates the predictive quality of the model. Moreover, specific friction model characteristics can be linked to the existence of torsional vibrations with and without stick-slip.
Adaptive Iterative Learning Control for Nonlinear Systems With Unknown Control Gain1
Authors: Chen Huadong , Jiang Ping
Published: March 2005

An adaptive iterative learning control approach is proposed for a class of single-input single-output uncertain nonlinear systems with completely unknown control gain. Unlike the ordinary iterative learning controls that require some preconditions on the learning gain to stabilize the dynamic systems, the adaptive iterative learning control achieves the convergence through a learning gain in a Nussbaum-type function for the unknown control gain estimation. This paper shows that all tracking errors along a desired trajectory in a finite time interval can converge into any given precision through repetitive tracking. Simulations are carried out to show the validity of the proposed control method.
Blind System Identification of Noncoprime Multichannel Systems and Its Application to Noninvasive Cardiovascular Monitoring
Authors: Zhang Yi , Asada H. Harry
Published: March 2005

Multichannel blind system identification (MBSI) is a technique for estimating both an unknown input and unknown channel dynamics from outputs measured at different points of the system. MBSI is a powerful tool particularly for the identification and estimation of dynamical systems in which a sensor, for measuring the input, is difficult to place. MBSI algorithms, however, are not applicable unless the transfer functions of individual channels are coprime, i.e., sharing no common dynamics among the channels. This paper presents a MBSI method, called intermediate input identification (IIID), applicable to multichannel, noncoprime systems containing common dynamics. A variable is introduced to split the original multichannel system into coprime multichannel subsystems and the one consisting of common dynamics. A modified MBSI method is used for identifying the coprime distinct channel dynamics, while the common dynamics is identified based on its unforced response. Identifiability conditions using linear complexity are obtained for both known and unknown model structures. Uniqueness and other properties of the solution are examined. The IIID method is then applied to noninvasive monitoring of the cardiovascular system. The arterial network is modeled as a multichannel system where the blood flow generated by the left ventricle is the input and pressure profiles measured at different branches of the artery, e.g., brachial, carotid, and femoral arteries, are the outputs. While the direct measurement of the input requires a catheter to be inserted into the heart, the IIID method does not need invasive catheterization. It would allow us to estimate both the wave form of the input flow and the arterial channel dynamics from outputs obtained with noninvasive sensors placed at different branches of the arterial network. Numerical examples and simulations verify the major theoretical results and the feasibility of the method.
An Identification Method With Direct Acquisition of Reduced Order Model From a Steplike Response
Authors: Kosaka Manabu , Uda Hiroshi , Shibata Hiroshi
Published: March 2005

In this paper, we propose a deterministic off-line identification method performed by using input and output data with a constant steady-state output response. The method can directly acquire any order of reduced model without knowing the real order of a plant, in such a way that the intermediate parameters are uniquely determined so as to be orthogonal with respect to 0-N-tuple integral values of output error and irrelevant to the unmodeled dynamics. From the intermediate parameters, the co-efficients of a rational transfer function are calculated. In consequence, the method can be executed for any linear single-input single-output plant without knowing or estimating its order at the beginning. The effectiveness of the method is illustrated by numerical simulations and also by applying it to a two-mass system.
Home-experimental demonstrations of Hart’s frictional force rotator
Authors: Crawford Frank S.
Published: March 2005

A block, pushed steadily across the slope of a plane inclined to the horizontal at less than the critical angle, describes a straight-line trajectory having a direction independent of velocity. If instead the block is projected across the slope and then allowed to slide freely, it stops after describing a curved trajectory. For different initial velocities the stopping points all lie on the same straight line. For small inclinations of the plane this stopping-point line makes an angle with the direction of constant elevation that is just half the angle that the trajectory of the steadily pushed block makes with that direction.
Remark on the isotropic form of the Schwarzschild interior metric
Authors: Buchdahl H. A.
Published: March 2005

In the course of determining the Schwarzschild interior solution in isotropic coordinates it turns out that to a given density and coordinate radius there in general correspond two possible spheres which have distinct masses and distinct physical radii. This situation is here described in detail.
Electronic Cavendish device
Authors: Crandall R. E.
Published: March 2005

The Cavendish torsion–balance method of detecting gravitational forces, while elegant and highly educational, is difficult to arrange as a lecture demonstration. The chief reason for this is the large settling time for torque-induced rotation. Described here is an apparatus in which the torsion bar does not appreciably rotate. A simple electronic servomechanism is used to maintain rotational equilibrium as an external mass is introduced. The resulting servo correction voltage is proportional to the torque induced by gravity. This effect can be observed in tens of seconds.
The AIM 65 microcomputer as an aid to data collection in general physics laboratory experiments
Authors: Curd Steven E. , Geilker Charles D.
Published: March 2005

An efficient general-purpose microcomputer program for acquisition of time-occurrence data in the general physics laboratory using the AIM 65 is described. Many phenomena requiring periodic data taking up to 500 kHz can be investigated. The minimal hardware interfacing is presented.
Solitons in undergraduate laboratory
Authors: Bettini Alessandro , Minelli Tullio A. , Pascoli Donatella
Published: March 2005

Teaching nonlinear phenomena, from an experimental point of view, in a laboratory for undergraduates in physics has been a motivating experience. We report in this paper on an advanced undergraduate laboratory on solitons in water. After recalling the main aspects of the theory and the principal characteristics of the solitons, the experimental apparatus is described and the results obtained by some students are discussed. A systematic check of the properties of solitons is obtained. An overall evaluation of the laboratory is given at the end.
Death in a hot tub: The physics of heat stroke
Authors: Bartlett Albert A. , Braun Thomas J.
Published: March 2005

High environmental temperature and/or vigorous physical work will tend to cause a person’s body temperature to rise. In an attempt to maintain a normal body temperature of 37°C the body then increases its rate of dissipation of heat by mechanisms that involve large increases in the blood flow to the skin. When there is an increase in the fraction of the blood that flows to the skin, the fraction available to other organs will decrease. A decreased flow to the brain can cause unconsciousness or death. The basic elements of this competition can be represented in terms of a simple dc circuit. Here is an example where the elements of dc circuit theory can be coupled with basic concepts of thermodynamics to help demonstrate the complimentarity of different branches of physics and to help students in elementary physics courses to gain an improved understanding of an important physiological situation. Examples of this type seem to be absent from many of our texts for introductory courses in physics.
Numerical solutions of Van der Pol’s equation
Authors: Drish William F. , Wild Walter J.
Published: March 2005

A qualitative picture of the solution to Van der Pol’s equation, using rough phase plane plots, is obtained prior to using the Taylor and Modified Euler (TAME) method to obtain more exact phase plane plots. The character of the solution, which is a relaxation oscillation, is discussed. Finally, an application of Van der Pol’s equation to a dc motor–generator hookup is given.
Clock synchronization, a universal light speed, and the terrestrial red-shift experiment
Authors: Macdonald Alan Lang
Published: March 2005

This paper (i) gives necessary and sufficient conditions that clocks in an inertial lattice can be synchronized, (ii) shows that these conditions do not imply a universal light speed, and (iii) shows that the terrestrial red-shift experiment provides evidence that clocks in a small inertial lattice in a gravitational field can be synchronized.
Study of Fresnel diffraction fields with the use of television technique
Authors: Marek S. , Śniadek B.
Published: March 2005

A modified method for the study of Fresnel diffraction fields during lectures in physics is proposed. Television technique is applied. The outputs of a television camera are connected simultaneously to a television set and an oscilloscope. The oscilloscope permits the viewing of the light intensity distributions in the individual diffraction fringes of the patterns observed on the television screen.
Cost per million BTU of solar heat, insulation, and conventional fuels
Authors: Cohen Bernard L.
Published: March 2005

The cost per million BTU is calculated for insulation (useful heat saved) and for flat plate solar collector systems applied to space heating of houses and to water heating. Results are compared with cost per million BTU from conventional sources.
Small oscillations which are not harmonic
Authors: Ronveaux A.
Published: March 2005

We present an elementary situation where the anharmonicity of a periodic motion is related to the vanishing value of the kinetic part at equilibrium. A solid rolling on a horizontal plane and having zero curvature at equilibrium, realizes that condition. This study emphasizes the importance of nonanalytic potential V( x)=xα 1<α<2.
An undergraduate α-particle time-of-flight experiment for determining the mean excitation energy for electronic stopping power of Al, Cu, Ag, and Au
Authors: Desmarais D. , Duggan J. L.
Published: March 2005

A student experiment is presented in which α-particle time-of-flight measurements as well as direct α energy measurements are used to determine electronic stopping power parameters. For the time-of-flight measurements, α particles from a 244Cm source are allowed to pass through a 14.6-μm ΔE detector, then a foil, and finally come to rest in an E detector. The time-of-flight signals are obtained from the ΔE and E detectors. The measured energies and velocities are then used to determine Bloch’s constant in the Bethe stopping power theory for Al, Cu, Ag, and Au. These student results are then compared to the theory. In order to show the feasibility of this technique for other measurements, a 252Cf source is used to produce a fission fragment time-of-flight spectrum. The time resolution for the α group is 1.17 ns and that of the fission fragment light group is 1.68 ns.
Atomic spectroscopy and holography: A combined laboratory experiment at the intermediate undergraduate level
Authors: Bates Harry E.
Published: March 2005

Holography is a new and exciting field that has found many applications in physics and engineering. Atomic spectroscopy has been the experimental cornerstone of modern physics and chemistry. This paper reports on an intermediate undergraduate laboratory experiment that combines fundamental ideas and techniques of both fields. The student utilizes holographic techniques to make a small sinusoidal diffraction grating and then uses this grating to analyze the spectrum of hydrogen. The Rydberg constant can be determined from the wavelength, the angle between the laser beams used to make the grating, and the observed diffractions angles of lines of the Balmer series.
Constraints
Authors: van Kampen N. G. , Lodder J. J.
Published: March 2005

The constraints of classical mechanics are idealizations of stiff elastic forces. They can be derived from such forces in the limit of infinite stiffness, but this derivation presents some difficulties and the limit has to be taken carefully. In statistical mechanics it is no longer possible to idealize stiff potentials by constraints, not even approximately, except under a special and unrealistic restriction on the form of those elastic forces. In quantum mechanics the limit in general does not exist unless the same unrealistic condition is satisfied.
Physical interpretation of the Lorentz–Dirac equation
Authors: Glass E. N. , Huschilt J. , Szamosi G.
Published: March 2005

An interpretation of the Lorentz–Dirac equation, and its first iterated version, is presented. The interpretation is based on the work of Teitelboim involving the bound and radiated four-momentum of an accelerated charge.
Relativistic invariance and Zitterbewegung
Authors: Lock James A.
Published: March 2005

We examine the question of what it is about the structure of relativistic quantum mechanics that causes the nonintuitive phenomenon of the Zitterbewegung of particle position to exist. Further, we examine various assumptions concerning the measurement process which are implicit in the observation of Zitterbewegung.
On the sudden expansion of an infinite square well
Authors: Cordes J. G. , Kiang D. , Nakajima H.
Published: March 2005

It is shown that most initial states, upon sudden expansion of the wall of an infinite square well, lead to an infinite dispersion in the energy. Circumstances under which ΔE remains finite and constant are discussed. The situation with respect to a macroscopic system is examined.
A simple derivation of high-field mobility and transverse diffusion coefficient
Authors: Panat P. V. , Paranjape B. V.
Published: March 2005

We present an elementary derivation of high-field ion mobility and the transverse diffusion coefficient. Our results compare favorably with the Monte Carlo investigations of Skullerud. The results are applicable when the ion drift velocity vd is much larger than the thermal velocities of the neutrals and ions. Our results are simple enough to be useful for quick estimates of the high-field mobility and the diffusion coefficient is useful for various mass ratios.
Variational principle for the problem of small oscillations
Authors: Salas Brito A. L.
Published: March 2005

The problem of the motions of a system in the neighborhood of one of the orbits of the same system is formulated using a variational principle. The linearized equations of motion of the deviations from the orbit are obtained from it. As an example of the use of this approach the conditions for the stability of a plane orbit are derived.
Classical free-energy densities for harmonic chains: A pedagogic application of the transfer integral technique
Authors: Henry B. I. , Oitmaa J.
Published: March 2005

The classical free-energy density for both a monatomic and a diatomic chain of particles with harmonic coupling between nearest neighbors is calculated using (i) the transfer integral technique and (ii) real-space renormalization. It is shown that the results agree with the classical limit of the well-known quantum-mechanical free-energy densities for these chains.
Equation with the many fathers. The Klein–Gordon equation in 1926
Authors: Kragh Helge
Published: March 2005

In this essay I discuss the origin and early development of the first relativistic wave equation, known as the Klein–Gordon equation. In 1926 several physicists, among them Klein, Fock, Schrödinger, and de Broglie, announced this equation as a candidate for a relativistic generalization of the usual Schrödinger equation. In most of the early versions the Klein–Gordon equation was connected with the general theory of relativity. Klein and some other physicists attempted to express quantum mechanics within a five-dimensional unified theory, embracing general relativity as well as electrodynamics. Although this ambitious attempt attracted some interest in 1926, its impact on the mainstream of development in quantum mechanics was virtually nil.
Precession of elliptic orbits
Authors: Sivardière Jean
Published: March 2005

We present some applications of the Runge–Lenz invariants for the Kepler and harmonic oscillator problems. The precession rate of the elliptic orbits is calculated for various perturbations of the Kepler and harmonic potentials.
Force on a dielectric slab inserted into a parallel-plate capacitor
Authors: Margulies S.
Published: March 2005

A common example from intermediate-level electromagnetic theory, the calculation of the force acting on a dielectric slab partially inserted into a parallel-plate capacitor, is examined in detail. The physical origin of the force, ignored in most textbooks, is shown to be due to the fringe field. The standard textbook calculation, in which the fringe field is explicitly ignored, is examined. An analysis which includes the presence of the fringe field indicates that the standard result is valid, but under conditions other than those generally presented.
The Poynting vector in a transformer
Authors: Lorrain Paul
Published: March 2005

In any transformer the Poynting vector E×H points away from the primary winding into the field, and from the field into the secondary winding. The Poynting vector results from the superposition of the E=−∂A/∂t field associated with the changing magnetic flux and the H fields of the currents in the windings.
Resource Letter: XRA-1 X-ray astronomy
Authors: Canizares Claude R.
Published: March 2005

This Resource Letter provides a guide to the literature on x-ray astronomy. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of somewhat more specialized nature; and the letter A indicates rather specialized or advanced material. An asterisk (*) indicates those articles to be included in an accompanying reprint book.
Classroom simulation of the coupled motion of piano strings
Authors: Curzon F. L.
Published: March 2005

The movement of doubled strings is simulated on a device, described in the paper, which permits the main features of the motion to be seen in the classroom. When the strings move up and down together, the motion is heavily damped. For antisymmetric motion the damping rate is much smaller (the Weinreich mechanism). A simple model of the mechanism is discussed as it applies to the simulator. A less restricted solution of the coupled equations of motion is given in the Appendix.
Light distribution near the focal point of a two-dimensional lens
Authors: Marsh James S.
Published: March 2005

The distribution of light in the focal region of a lens in two dimensions is calculated in terms of the Fresnel integral. The result is a comparatively simple but very good analog for the focal region of a three-dimensional lens discussed by Born and Wolf. In particular the cigar-shaped channel through which the light penetrates the focal plane appears in the two-dimensional as well as the three-dimensional case.
How Olympic records depend on location
Authors: McFarland Ernie
Published: March 2005

The summer Olympics at Mexico City in 1968 produced a number of anomalous records in track and field, some of which can be explained by the effects of low air density and gravity at Mexico City, while others were the result of outstanding athletic performances.
A simple solution of the two-dimensional relativistic Kepler problem
Authors: Bruce Stanley A.
Published: March 2005

A two-dimensional electron is described by an appropriate spin 1/2 bi-dimensional Dirac equation. The special case of a hydrogenic atom in two dimensions is solved in order to obtain its energy spectrum and the total spread of its fine structure levels.
Argand diagrams, harmonic oscillators, and record-playing tonearms
Authors: Piccard Richard D.
Published: March 2005

The complex analysis of the driven, damped, harmonic oscillator is reviewed for the specific case that the driving force is produced by ‘‘wiggling the other end of the spring,’’ a case which many find intuitively appealing. The solution is examined using the Cartesian and polar presentations in the complex plane. The record-playing tonearm is particularly suited as a ‘‘practical example’’ because it naturally leads to a question that is much easier to answer in terms of the Argand diagram: What will the cartridge output be?
Why Ampère did not discover electromagnetic induction
Authors: Williams L. Pearce
Published: March 2005

In 1832, after Michael Faraday had announced his discovery of electromagnetic induction, Andre-Marie Ampère claimed that he had actually discovered the induction of one current by another in 1822. In fact, he had, but did not really publish the fact at that time. This article explores the reasons for Ampère’s failure to lay claim to a discovery that would have guaranteed him scientific immortality.
Special relativity completed: The source of some 2s in the magnitude of physical phenomena
Authors: Strandberg M. W. P.
Published: March 2005

Some factors of 2 relate predictions made of relativistic systems by the special and the general theory. Conventional wisdom often assigns the source of the factors of 2 to complicated kinematical effects of general relativity. It is pointed out that special relativity plus the complete form of the equivalence postulate can be made into a logical structure which allow them, in a heuristic manner, to predict not only local effects, but also some global effects described by the general theory. Calculation of the gravitational deflection of light and the precession of the perihelion of planets using special relativity with the complete equivalence postulate makes the origin of some 2s simple to understand. From the time of Minkowski on, the requirements and constraints on the theory of relativity have been demonstrated using group theoretical arguments. The general observation is made that physics teaching would be improved in the persuasiveness of its epistemology if the properties of physical systems which are displayed by the group theory of representations played a larger role in the physics curriculum.
From wave to geometrical optics
Authors: Gauthier N. , Rochon P. , Racey T. J.
Published: March 2005

The problem of diffraction by a long perfectly reflecting cylinder of radius R which is illuminated by light of wave vector k is considered from the standpoint of the scalar theory of light. The transition to geometrical optics is shown to occur as kR→∞ and a comparison between the present predictions and those of Maxwell’s theory is made.
A summer program for high school physics teachers
Authors: Heller Patricia A. , Hobbie Russell K. , Jones Roger S.
Published: March 2005

In the summer of 1985 we ran a workshop for high school physics teachers, sponsored by the National Science Foundation under its program of Honors Workshops for Pre-College Teachers of Science and Mathematics. The summer experience consisted of a five-week workshop and a four-week industrial experience. The teachers had a wide variety of backgrounds and needs, which were accommodated in the workshop. This paper describes how the workshop was run, what activities were successful, and where we encountered problems.
The time–asymmetry paradox
Authors: Hurley James
Published: March 2005

The fundamental laws of microscopic physics are time-reversal invariant. The laws governing the behavior of macroscopic systems are not time-reversal invariant. If macroscopic systems are collections of microscopic components, how do we reconcile this dichotomy?
The dynamically shifted oscillator
Authors: Hartmann W. M.
Published: March 2005

The dynamically shifted oscillator is described by an equation of motion which includes both a Hookian restoring force and a nonlinear force which depends only upon the sign of the displacement. Exact expressions are obtained for the amplitude-dependent frequency and for the displacement waveform. The theory is applied to the study of the vibrations of the two-point librator and of the spring doorstop.
Justifying the simple diode equation
Authors: Moloney Michael J.
Published: March 2005

In elementary texts, derivations of the equation I=I0[exp(qV/kT)−1] (the ‘‘simple diode’’ equation) all depend on conditions valid when no current flows, an apparently contradictory situation. Because introductory texts justify this only qualitatively, it is desirable to do an explicit calculation which explores the limits of the equation when current actually does flow—a procedure carried out in this paper by manipulating the current density equations and integrating them across the space-charge layer (SCL). The calculation shows the ‘‘simple diode equation’’ to be valid if the width of the SCL is small compared to the diffusion length of either an elecron or a hole. This implies relatively few collisions in the SCL and thus clarifies why SCL recombination may also be neglected in the ‘‘simple diode’’ regime.
A dimerized Kronig–Penney model
Authors: Goñi Alejandro R. , Rojo Alberto G. , Martinez E. N.
Published: March 2005

We find the band structure of a dimerized Kronig–Penney model, and show its relationship to both periodicity and the transmission coefficient of the dimer, whose resonances lead to the vanishing of some of the band gaps as the dimerization varies.
Path-integral quantization of constrained Hamiltonian dynamical system: A pedagogical example
Authors: Sengupta Manan
Published: March 2005

The concept of constrained Hamiltonian dynamical systems and their quantization, introduced by Dirac, constitutes one of the most fundamental contributions to the development of the canonical formalism in recent times. Dirac’s concepts were later incorporated into the path-integral formulation of quantum mechanics by Faddeev, which played an important role in understanding some subtle aspects in the quantization of non-Abelian gauge theory. An example is given from nonrelativistic quantum mechanics which illustrates the formalism through simple analogy.
Maxwellian distribution versus Rayleigh distribution
Authors: Menon V. J. , Agrawal D. C.
Published: March 2005

The inverse problem of deducing the molecular velocity distribution from a given density function is solved analytically. The results corresponding to two physically interesting systems viz. Maxwellian and Rayleigh gases are compared.
Laboratory demonstrations through the use of a general purpose correlator
Authors: Basano L. , Ottonello P.
Published: March 2005

We describe a concise introduction to the correlation of continuous signals based on a series of demonstrations performed with the aid of a new low-cost correlator. The significant novelty of this instrument is that, unlike previous versions, it is able to correlate both continuous and pulsed signals. It may therefore be employed as a teaching aid in the student laboratory for introductory demonstration experiments in random noise theory and in photoelectron statistics.
On Feynman’s formula for the electromagnetic field of an arbitrarily moving charge
Authors: Janah A. R. , Padmanabhan T. , Singh T. P.
Published: March 2005

A simple derivation of Feynman’s formula for the electromagnetic field of an arbitrarily moving charge, starting from Maxwell’s equations, is presented. Feynman’s formula is also related to the standard expressions for the fields of a moving charge.
Semiclassical approximation and exact evaluation of the propagator for a harmonic oscillator with time-dependent frequency
Authors: Natividade César P.
Published: March 2005

The propagator for a one-dimensional harmonic oscillator with time-dependent frequency is calculated exactly by the semiclassical approximation method.
Kinetic illustration for thermalization
Authors: Berger Jorge
Published: March 2005

A detailed self-consistent kinetic model is studied, which is a suitable idealization for the thermalization process of a gas in a container. Thermalization is due to collisions against a wall that is in thermal motion. The present situation is an opposite extreme to the ideal gas considered by Boltzmann. An exact equation is obtained for the time evolution of the gas distribution. The results illustrate the existing general theories and clarify the difficulties that arose in a previous work.
Semiclassical treatment of the periodic potential
Authors: Holstein Barry R.
Published: March 2005

The use of a general periodic potential is addressed using both semiclassical path integral and instanton techniques. Identical band structure is shown to result from either approach.
Culvert whistlers revisited
Authors: Crawford Frank S.
Published: March 2005

A geometric explanation is given for the culvert whistler demonstration. The method is applied to the echo tube at the San Francisco Exploratorium. (AIP)
Dielectric slab in a parallel-plate condenser
Authors: Utreras-Díaz Constantino A.
Published: March 2005

The problem of a dielectric slab inside a parallel-plate capacitor is considered from the point of view of a simple force calculation. The usual method of presenting this problem, found in most textbooks, is via energy considerations. The method presented here allows corrections to the well-known result to be obtained.
The amazing many colored relativity engine
Authors: Mermin N. David
Published: March 2005

A simple microcomputer program is described that makes beginning students think relativistically about elementary space and time measurements. The program allows such students to perform their own gedanken experiments to learn the consequences a clock synchronization convention has for measurements of the lengths or speeds of moving objects and the rates of moving clocks. To use the program requires no knowledge of physics, algebra, or geometry.
Demonstrating superconductivity at liquid nitrogen temperatures
Authors: Early E. A. , Seaman C. L. , Yang K. N. , Maple M. B.
Published: March 2005

This article describes two demonstrations of superconductivity at the boiling temperature of liquid nitrogen (77 K) using the 90 K superconductor YBa2Cu3O7−δ(δ≊0.2). Both demonstrations involve the repulsion of a permanent magnet by a superconductor due to the expulsion of the magnetic field from the interior of the latter. In the first demonstration, the repulsion is manifested in the separation of a permanent magnet and a superconductor that are suspended from separate threads, while in the second it results in the levitation of a permanent magnet above a flat superconducting disk.
Experience with videotaped problem solutions for introductory physics courses
Authors: Johnson Walter H.
Published: March 2005

The results of a project at the University of Minnesota to test the usefulness of videotaped solutions of physics problems for students in introductory courses will be described. The system employed to make these videotapes and the videotaping procedures will be reviewed. Student evaluations of this form of teaching aid will be included.
Rounded spikes of kompeitoh and scaling relations
Authors: Murai Nobuyuki , Nakata Tomoichi
Published: March 2005

Kompeitoh is sugar candy, a piece of which has many remarkable rounded spikes. A one-dimensional model of kompeitoh is presented using the Monte Carlo method to investigate how the spikes develop in the production process. Scaling relations are revealed, which ensure approximate geometrical similarity in its growth. Its shape is expected to be round without spikes after enough time has elapsed.
Gauge invariance and quantization
Authors: Holstein Barry R.
Published: March 2005

Quantizing theories such as quantum electrodynamics that contain a gauge invariance are discussed via a simple pedagogical example. Canonical and path integral quantization methods are compared.
Acoustical numerology and lucky equal temperaments
Authors: Hall Donald E.
Published: March 2005

Equally tempered musical scales with N steps per octave are known to work especially well in approximating justly tuned intervals for such values as N=12, 19, 31, and 53. A quantitative measure of the closeness of such fits is suggested, in terms of the probabilities of coming as close to randomly chosen intervals as to the justly tuned targets. When two or more harmonic intervals are considered simultaneously, this involves a Monte Carlo evaluation of the probabilities. The results can be used to gauge how much advantage the special values of N mentioned above have over others. This article presents the rationale and method of computation, together with illustrative results in a few of the most interesting cases. References are provided to help relate these results to earlier works by music theorists.
The calculation of second-order terms in time-dependent perturbation theory
Authors: Moretti Paolo
Published: March 2005

Considering second-order terms in time-dependent perturbation expansions, the role of the nonresonant part is pointed out and explained using a simple property of the generalized function ζ(x); the results are shown to be independent of the preparation function f(t).
Some thoughts on introductory physics courses
Authors: French A. P.
Published: March 2005

The main features of standard introductory courses for prospective scientists and engineers are reviewed and criticized. The argument is made that concern with content should be drastically reduced, and that the main emphasis should be placed on physics as a process for exploring and interpreting the real world.
Adiabatic and nonadiabatic processes in classical and quantum mechanics
Authors: Maris Humphrey J. , Xiong Quan
Published: March 2005

The problem of two coupled pendulums, one of which has a length that varies with time so that the pendulum passes through resonance with the other is considered. An expression is derived for the amount of energy transferred between the pendulums as a function of the rate of change of the length and the strength of the coupling spring. This is done by making a connection with the quantum mechanical two-level system.