Physical Sciences and Mathematics Commons^™

The Paradox Of Ideology, Justin Schwartz

Justin Schwartz

A standard problem with the objectivity of social scientific theory in particular is that it is either self-referential, in which case it seems to undermine itself as ideology, or self-excepting, which seem pragmatically self-refuting. Using the example of Marx and his theory of ideology, I show how self-referential theories that include themselves in their scope of explanation can be objective. Ideology may be roughly defined as belief distorted by class interest. I show how Marx thought that natural science was informed by class interest but not therefore necessarily ideology. Capitalists have an interest in understanding the natural world (to a …

Toxicokinetics And Metabolism Of Aniline And 4-Chloroaniline In Medaka (Oryzias Latipes), Steven P. Bradbury, Julia M. Dady, Patrick N. Fitzsimmons, Michelle M. Voit, Dean E, Hammermeister, Russell J. Erickson

Steven P. Bradbury

The in vivo toxicokinetics and in vitro hepatic microsomal metabolism of (14C)aniline and (14C)4-chloroaniline in medaka (Oryzias latipes) were investigated to provide a basis upon which to interpret the toxicological responses of small aquarium fish to aniline derivatives. During static aqueous exposures of up to 320 min, parent equivalents failed to reach steady state and results from depuration studies clearly demonstrated biphasic elimination. Due to low elimination rates, 40 to 20% of absorbed aniline and 4-chloroaniline doses, respectively, remained within the fish through 330 min postexposure. Based on an analysis of excreted metabolites, N-acetylation was the dominant route of in …

A Non-Invasive Neurotoxicity Assay Using Larval Medaka, Steven P. Bradbury, Dave Featherstone, Charles D. Drewes, Joel R. Coats

Steven P. Bradbury

We present a method for non-invasive electrophysiological analysis of rapid escape responses in intact, freely behaving larval medaka (Oryzias latipes) before and after short-term exposure to environmental toxicants. Recordings are obtained as a larval medaka swims in a small chamber of water above pairs of recording electrodes etched onto a printed circuit board. When the chamber is briefly vibrated by a sinusoidal pulse from a speaker attached to the grid, a stereotyped Mauthner cell-initiated escape response is evoked. The following parameters were quantified from recordings: 1) Mauthner axon conduction velocity, 2) delay between Mauthner axon spike and motoneuron spike in …

Tables Of Coincidence Orientations For Ordered Tetragonal L Lo Alloys For A Range Of Axial Ratios, Abha Singh, Alexander H. King

Alexander H. King

In this paper we develop and apply techniques for computation of CSL, DSCL and step-vector data for grain boundaries in tetragonal materials for a range of axial ratios. This has application to L10 alloys including TiA1, which is a candidate for lightweight high-temperature structural applications. Our results are compared with others and found to be more accurate and complete. We provide data for a wider range of axial ratios than those considered by previous workers. We have also derived equivalent quaternions for tetragonal crystals in tetragonal-crystal coordinates and listed conditions for selecting a unique reduced rotation in tetragonal-crystal coordinates so …

A Geometrical Rationalization Of The Special Properties Of The 14° [001] Grain Boundary In Yba2cu3o7−Δ, Alexander H. King, Abha Singh

Alexander H. King

14° [001] tilt grain boundaries in YBa2Cu3O7−δ have been found to exhibit anomalously good superconducting critical currents, associated with magnetic flux pinning, although no special interfacial structure has heretofore been associated with this misorientation. We present an analysis of the geometry of the grain boundary in question and show that it can correspond to a special interface, within the definition of constrained lattice coincidence, which may lead to new understanding of the superconducting behavior of grain boundaries. Our analysis shows that the tetragonal‐to‐orthorhombic phase transformation may have important effects upon grain boundary structure and properties, indicating new approaches to producing …

Doping And Pressure Studies On Ybbipt, A. Lacerda, R. Movshovich, M. F. Hundley, Paul C. Canfield, D. Arms, G. Sparn, J. D. Thompson, Z. Fisk, N. E. Philips, H.-R. Ott

Paul C. Canfield

The compound YbBiPt exhibits an extremely large low‐temperature C/T (γ∼8 J K−2 mol−1/Yb) which, if due solely to a renormalized effective mass, would make this material the heaviest correlated electron system known to date. In the Kondo model, the very large γ corresponds to a small characteristic energy scale that is expected to be pressure dependent. We have studied the effect of chemical pressure on YbBiPt single crystals by heat‐capacity measurements on Y and Lu‐doped samples. We have also made preliminary low‐temperature measurements under hydrostatic pressure of the heat capacity (300 mK≤T≤2 K, up to 8 kbar) and resistance (30 …

Nqr Study Of Local Structure And Cooling Rate‐Dependent Superconductivity In La2cuo4+Δ, A. P. Reyes, E. T. Ahrens, P. C. Hammel, J. D. Thompson, Paul C. Canfield, Z. Fisk, R. H. Heffner, J. E. Schirber

Paul C. Canfield

Preliminary results of structural studies in oxygen‐annealed La2CuO4+δ(δ∼0.03) using 139La nuclear quadrupole resonance (NQR) spectroscopy are reported. Superconducting critical temperatures were found to depend on the rate of cooling through a narrow temperature range near 195 K. Analysis of the 139La NQR spectra reveal that lanthanum atoms in the oxygen‐rich metallic region occupy two sites having different local environments. One site has a structural configuration closely related to the stoichiometric oxygen‐poor compound. The second appears only below 200 K and exhibits a large shift and broad distribution of NQR frequency ν Q . Shifts in ν Q in the vicinity …

Field Experiments In A Fractured Clay Till: 2. Solute And Colloid Transport, Larry Mckay, Robert W. Gillham, John A. Cherry

Larry McKay

A field tracer experiment was conducted in a lateral flow field in the weathered and highly fractured upper 6 m of a 40-m-thick clay-rich till plain in southwestern Ontario. In the upper 3 m where fractures are closely spaced (<0.13 m) the advancing front (C/C0 = 0.01) of the nonreactive solute tracers, bromide and 18O, migrated at rates of 0.01 to 0.07 m/d, over distances of 4 and 6 m and under a lateral hydraulic gradient of 0.24. In this same zone, two strains of colloid-sized bacteriophage tracers migrated at rates of 2 to >5 m/d. Simulations with a discrete fracture/porous matrix flow and transport model, which used the cubic law for flow in fractures, showed that diffusion of the solutes, but not the much larger colloids, into the matrix pore water between fractures is sufficient to cause the observed difference in solute and colloid transport rates. Transport-derived and hydraulic conductivity-derived fracture aperture values …

Field Experiments In A Fractured Clay Till: 1. Hydraulic Conductivity And Fracture Aperture, Larry Mckay, John A. Cherry, Robert W. Gillham

Larry McKay

Field values of horizontal hydraulic conductivity measured in the upper 1.5–5.5 m of a weathered and fractured clay-rich till were strongly influenced by smearing around piezometer intakes, which occurs during augering, and by the physical scale of the measuring device. Values measured in conventional augered piezometers were typically 1–2 orders of magnitude lower than those measured in piezometers designed to reduce smearing. Measurements of hydraulic conductivity in small-scale seepage collectors or piezometers, which typically intersect fewer than 10 fractures, vary over a much greater range, 10−10 to 10−6 m/s, than large-scale values based on infiltration into 5.5-m-deep trenches which intersect …

Uniqueness Of Radial Solutions Of Semilinear Elliptic Equations, Man Kam Kwong, Yi Li

Yi Li

E. Yanagida recently proved that the classical Matukuma equation with a given exponent has only one finite mass solution. We show how similar ideas can be exploited to obtain uniqueness results for other classes of equations as well as Matukuma equations with more general coefficients.

Radial Symmetry Of Positive Solutions Of Nonlinear Elliptic Equations In Rn, Yi Li, Wei-Ming Ni

Yi Li

No abstract provided.

On The Positive Solutions Of The Matukuma Equation, Yi Li

Yi Li

No abstract provided.

Quantam Wave Turbulence, Alejandro Garcia, M. Haeri, S. Putterman, P. Roberts

Alejandro Garcia

The nonlinear quantum kinetic equation for the interaction of sound waves is solved via analytic and numerical techniques. In the classical regime energy cascades to higher frequency (ω) according to the steady-state power law ω-3/2. In the quantum limit, the system prefers a reverse cascade of energy which follows the power law ω-6. Above a critical flux, a new type of spectrum appears which is neither self-similar nor close to equilibrium. This state of nonlinear quantum wave turbulence represents a flow of energy directly from the classical source to the quantum degrees of freedom.

Timestamp Semantics And Representation., Curtis Dyreson, Richard T. Snodgrass

Curtis Dyreson

Many database Management systems and operating systems provide support for time values. At the physical level time values are known as timestamps. A timestamp has a physical realization and a temporal interpretation. The physical realization is a pattern of bits while the temporal interpretation is the meaning of each bit pattern, that is, the time each pattern represents. All previous proposals defined timestamps in terms of seconds. However, as we show, there are at least seven definitions of this fundamental time unit. We propose a more precise temporal interpretation, the time-line clock, that constructs a time-line by using different well-defined …

Proton‐Donor Properties Of Water And Ammonia In Van Der Waals Complexes. Be–H2o And Be–Nh3, G. Chalasinski, M. M. Szczesniak, Steve Scheiner

Steve Scheiner

The potential energy surfaces (PES) of Be–H₂O and Be–NH₃ are studied with particular attention to characterization of proton‐donor properties of water and ammonia. Calculations were performed by means of both supermolecular and intermolecular Møller Plesset perturbation theory. The Be–H₂O PES reveals two van der Waals minima: the C_2v minimum (D_e=176 cm⁻¹, R_e=6.5 bohr), and the H‐bonded minimum (D_e=161 cm⁻¹, R_e=7.5 bohr), separated by a barrier of 43 cm⁻¹ at the T‐shaped configuration. The Be–NH₃ PES reveals only …

Accounting For Saturation Effects In Pulsed Infrared Laser Excited Photothermal Spectroscopy, Stephen E. Bialkowski

Stephen E. Bialkowski

Equations that relate photothermal lens focal lengths and photothermal deflection angles to saturation absorption coefficients are derived. These equations are derived for two-level absorbers with both homogeneously and inhomogeneously broadened transitions. Initial and time-dependent photothermal lens signals are calculated. Equations describing the zero-time signals are exact to within the simplifying assumptions of the derivation, while the time-dependent signals are approximate. The approximation is performed by the use of a finite series of Gaussian functions to model the temperature change profile distorted by nonlinear absorption. The excitation irradiance-dependent signal behavior for rectangular and exponential excitation pulse time profiles for homogeneously and …

F-Region Plasma Drifts Over Arecibo: Solar Cycle, Seasonal And Magnetic Activityeffects, Bela G. Fejer

Bela G. Fejer

We have used Arecibo incoherent scatter measurements from 1981 to 1990 to determine the characteristics of low-latitude F region plasma drifts. The measurements show large day-to-day variability even during magnetically quiet periods. The average poleward/perpendicular plasma drifts do not change significantly with season and solar cycle except in the midnight-morning sector. The zonal drifts show clear solar cycle and seasonal effects. The afternoon-nighttime eastward drifts increase with solar flux; the westward drifts in the early morning-afternoon sector show a large increase from summer to winter but are independent of solar activity. The two perpendicular velocity components also respond differently to …

Beam Collapse As An Explanation Foranomalous Ocular Damage, James A. Powell, J. V. Moloney, A. C. Newell, R. A. Albanese

James A. Powell

The basic mathematical phenomena relevant to ocular damage caused by ultrashort laser pulses are discussed with the use of mathematical results and numerical modeling. The primary effects of nonlinear self-focusing and beam collapse are examined in the ocular safety context. Finite-time material response and group-velocity dispersion are discussed as possible mitigating factors. An argument is presented that indicates that the initial stages of beam collapse are essentially two-dimensional. Experiments are suggested that might help distinguish the most important contributing factors in the damage regime. The numerical methodology is detailed in an appendix.

Intelligent, Integrated, Interactive Design, David Brown, R. Sisson, D. Zenger, J. Bausch, J. O'Shaughnessy

David C. Brown

No abstract provided.

Anomalies For Pedestrians, Br Holstein

Barry R Holstein

The subject of anomalies, i.e., quantum mechanical symmetry breaking, is addressed using only basic quantum mechanics. Examples from different areas of physics are examined

Synthesis And Structure Of A Product, Formed During Dna Nicking With A Cyclometallated Nuclease, Consisting Of An Adenine Bridging Two Palladium(Ii) Complexes., J. Suggs, Michael Du\Ube, Michael Nichols

Michael A Nichols

Journal of the Chemical Society, Chemical Communications

Study Of The Violation Of Parity In Nuclear Beta-Decay Via A Relative Beta-Polarization Measurement With Polarized In-107 Nuclei, N Severijns, R Prieels, M Allet, J Camps, P Demoor, J Deutsch, F Gimenonogues, Br Holstein, Bh King, O Naviliatcuncici, I Pepe, Pa Quin, P Schuurmans, R Siebelink, W Vanderpoorten, J Vanhaverbeke, L Vanneste, J Wouters

Barry R Holstein

No abstract provided.

Implementation Of The Surface Mining Control And Reclamation Act In Pennsylvania: A Decade Later, John Dernbach

John C. Dernbach

No abstract provided.

Solvable Quantum Mechanical Examples Of Broken Supersymmetry, Asim Gangopadhyaya

Asim Gangopadhyaya

Application Of Square Wave Voltammetry For Electrochemical Detection In Gradient Elution Hplc, John Roush, Mark Anderson

Mark R. Anderson

The utility of square-wave voltammetry with a conventionally sized indicator electrode for use in the detection of gradient elution HPLC applications is demonstrated. A redesigned electrochemical detector cell, based upon a type of wall-jet design, provides more efficient potential control and allows the voltammetric detection. The minimum detectable quantity and linear dynamic range for the new detector design were found to be 13pg and 5 orders of magnitude, respectively, comparable to other electrochemical detectors. In the separation of a test mixture containing hydroquinone. bromohydroquinone, catechol, resorcinol, and phenylhydroquinone baseline resolution of all five components is obtained in 12 minutes using …

Quantum Correlations And 3 Body Decays At A Phi-Factory, Jf Donoghue, Br Holstein, Af Perez

Barry R Holstein

No abstract provided.

Visualization Of Particulant Foulant Layer Formation In Microfiltration, R. Wakeman, Caroline Lubert

Caroline P Lubert

No abstract provided.

Phenomenographic Research And The Measurement Of Understanding: An Investigation Of Students' Conceptions Of Speed, Distance And Time, P Ramsden, Geoff Masters, Andrew Stephanou, E Walsh, E Martin

Prof Geoff Masters AO

No abstract provided.

Physics Students' Understanding Of Relative Speed: A Phenomenographic Study, Eleanor Walsh, Gloria Dall'alba, John Bowden, Elaine Martin, Ference Marton, Geoff Masters, Paul Ramsden, Andrew Stephanou

Prof Geoff Masters AO

It is important that students of physics develop both quantitative and qualitative understanding of physical concepts and principles. Although accuracy and reliability in solving quantitative problems is necessary, a qualitative understanding is required in applying concepts and principles to new problems and in real-life situations. If students are not able to understand what underlies quantitative problem-solving procedures nor interpret the solution in physical terms, it is questionable whether they have developed an adequate understanding of physics. The research reported here is part of a larger phenomenographic study that is concerned with the assessment of physics students' understanding of some basic …

The Other Ninety-Six Percent, John C. Dernbach

John C. Dernbach

No abstract provided.