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Articles 4921 - 4950 of 4978

Full-Text Articles in Physical Sciences and Mathematics

Flow Injection Sample Introduction For Atomic-Absorption Spectrometry: Applications Of A Simplified Model For Dispersion, Julian Tyson, A. B. Idris Jan 1981

Flow Injection Sample Introduction For Atomic-Absorption Spectrometry: Applications Of A Simplified Model For Dispersion, Julian Tyson, A. B. Idris

Chemistry Department Faculty Publication Series

No abstract provided.


Flow Injection Techniques In Atomic Absorption Spectrometry, Julian Tyson Jan 1981

Flow Injection Techniques In Atomic Absorption Spectrometry, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Centers Of Polymer Research; Polymer Science In Kyoto, Japan, Otto Vogl, A. Nakajima Jan 1981

Centers Of Polymer Research; Polymer Science In Kyoto, Japan, Otto Vogl, A. Nakajima

Otto Vogl

No abstract provided.


Synoptic Climatology Of The Western United States In Relation To Climatic Fluctuations During The Twentieth Century, R. G. Barry, G. Kiladis, Raymond S. Bradley Jan 1981

Synoptic Climatology Of The Western United States In Relation To Climatic Fluctuations During The Twentieth Century, R. G. Barry, G. Kiladis, Raymond S. Bradley

Raymond S Bradley

An objectively derived catalogue of daily pressure patterns for 11199-1974 has been prepared for the western United States. The temperature and precipitation characteristics of the major types are described and a more detailed analysis for Colorado in extreme cold and warm months shows that the sign of the anomalies for each type is generally consistent with expectation hased Oil the prohable airflow patterns. A regression analysis of type frequencies versus temperature and precipitation anomalies for 1899--1970 at stations east and west of the Continental Divide in the Rocky Mountain states shows that useful explanation of variance is obtained only for …


Structure-Factor Measurements In 4he At Saturated Vapor Pressure For 1.38<~T<~4.24 K, Robert Hallock, H. N. Robkoff Jan 1981

Structure-Factor Measurements In 4he At Saturated Vapor Pressure For 1.38<~T<~4.24 K, Robert Hallock, H. N. Robkoff

Robert Hallock

We present the results of measurements of the liquid structure factor, S(k), for liquid 4He at saturated vapor pressure at seven temperatures between 1.38 and 4.24 K over the momentum-transfer range k<~5.1 Å-1. The results are compared with previous measurements carried out by both x-ray and neutron scattering techniques. Comparison with recent theoretical work emphasizes the importance of higher-order correlations and more realistic potentials in the description of the liquid. Measurements in the vicinity of the λ transition document a loss in spatial order as the liquid is cooled through Tλ.


Phase Separation In 3he-4he Mixture Films, Robert Hallock, F. M. Ellis, M. D. Miller, R. A. Guyer Jan 1981

Phase Separation In 3he-4he Mixture Films, Robert Hallock, F. M. Ellis, M. D. Miller, R. A. Guyer

Robert Hallock

We report detailed observations of the propagation of third sound in 3He-4He mixture films as a function of temperature and 3He concentration. The data are consistent with a simple model for the film and we conclude that thin 3He-4He mixture films exhibit nearly complete phase separation.


Associative Search Network: A Reinforcement Learning Associative Memory, Andrew G. Barto, Richard S. Sutton, Peter S. Brouwer Jan 1981

Associative Search Network: A Reinforcement Learning Associative Memory, Andrew G. Barto, Richard S. Sutton, Peter S. Brouwer

Computer Science Department Faculty Publication Series

An associative memory system is presented which does not require a "teacher" to provide the desired associations. For each input key it conducts a search for the output pattern which optimizes an external payoff or reinforcement signal. The associative search network (ASN) combines pattern recognition and function optimization capabilities in a simple and effective way. We define the associative search problem, discuss conditions under which the associative search network is capable of solving it, and present results from computer simulations. The synthesis of sensory-motor control surfaces is discussed as an example of the associative search problem.


Centers Of Polymer Research; Polymer Science In Silesia, Poland:Gliwice, Zabrze, Otto Vogl, W. Pradellok Dec 1980

Centers Of Polymer Research; Polymer Science In Silesia, Poland:Gliwice, Zabrze, Otto Vogl, W. Pradellok

Emeritus Faculty Author Gallery

No abstract provided.


Centers Of Polymer Research; Polymer Science In Silesia, Poland:Gliwice, Zabrze, Otto Vogl, W. Pradellok Dec 1980

Centers Of Polymer Research; Polymer Science In Silesia, Poland:Gliwice, Zabrze, Otto Vogl, W. Pradellok

Otto Vogl

No abstract provided.


Polymer Science In Lodz, Poland, Otto Vogl, P. Kubisa Nov 1980

Polymer Science In Lodz, Poland, Otto Vogl, P. Kubisa

Emeritus Faculty Author Gallery

No abstract provided.


Polymer Science In Lodz, Poland, Otto Vogl, P. Kubisa Nov 1980

Polymer Science In Lodz, Poland, Otto Vogl, P. Kubisa

Otto Vogl

No abstract provided.


Secular Fluctuations Of Temperature In The Rocky Mountain States And A Comparison With Precipitation Fluctuations, Raymond S. Bradley Jul 1980

Secular Fluctuations Of Temperature In The Rocky Mountain States And A Comparison With Precipitation Fluctuations, Raymond S. Bradley

Raymond S Bradley

Fluctuations of temperature in the Rocky Mountain states of Idaho. Montana. Wyoming. Colorado and Utah are analyzed forthe period 1891-1978. Prior to 1891. data forthis area are too sparse to make meaningful generalizations. After screening temperature data for homogeneity. selected records are used to map seasonal mean temperature departures from 1941-70 means. In all seasons. mean temperatures were higher by 1-I.soC during the last 40 years compared to the previous 40-50 years. However. spring and fall temperatures have been declining since the period maximum in the late 1930·s. Pentad mean winter and summer temperatures show a statistically significant temperature increase …


Fluid-Structure-Factor Measurements In 4he For 5.5<=T<=7.0 K, Robert Hallock, D. A. Ewen, H. N. Robkoff May 1980

Fluid-Structure-Factor Measurements In 4he For 5.5<=T<=7.0 K, Robert Hallock, D. A. Ewen, H. N. Robkoff

Robert Hallock

We report precise measurements of the structure factor S(k) as a function of the momentum transfer k for 4He at T=5.5 and 6.5 K in the density range 10<~ρ<~155 kg/m3. No theoretical predictions that can be tested against the data are available. The recent theoretical work by Bruch et al. at T=7.0 K, ρ=69.6 kg/m3 is in only limited agreement with our experimental data at T=7.0 K, ρ=69.0 kg/m3.


Third Sound And The Decay Of Persistent Currents In Unsaturated 3he-4he Films, Robert Hallock May 1980

Third Sound And The Decay Of Persistent Currents In Unsaturated 3he-4he Films, Robert Hallock

Robert Hallock

We report the observation of metastable currents in unsaturated 3He-4He-mixture films. The decay rate of these currents is found to be an increasing function of 3He concentration in the film. A simple model for the role of the 3He, adequate to explain our observations of the concentration dependence of the third-sound velocity, does not agree with the measured decay rates.


Analytical Aspects Of Absorption Spectroelectrochemistry At A Platinum Electrode- Ii: Quantitative Basis And Study Of Organic Compounds, Julian Tyson, T. S. West Jan 1980

Analytical Aspects Of Absorption Spectroelectrochemistry At A Platinum Electrode- Ii: Quantitative Basis And Study Of Organic Compounds, Julian Tyson, T. S. West

Chemistry Department Faculty Publication Series

No abstract provided.


Centers Of Polymer Research; Polymer Science And Technology In The Ddr, Otto Vogl Dec 1979

Centers Of Polymer Research; Polymer Science And Technology In The Ddr, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.


Centers Of Polymer Research; Polymer Science And Technology In The Ddr, Otto Vogl Dec 1979

Centers Of Polymer Research; Polymer Science And Technology In The Ddr, Otto Vogl

Otto Vogl

No abstract provided.


The Differential Capacitance Of Magnetite, Julian Tyson Jan 1979

The Differential Capacitance Of Magnetite, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Analytical Aspects Of Absorption Spectroelectrochemistry At A Platinum Electrode- I Study Of Metal Ions, Julian Tyson, T. S. West Jan 1979

Analytical Aspects Of Absorption Spectroelectrochemistry At A Platinum Electrode- I Study Of Metal Ions, Julian Tyson, T. S. West

Chemistry Department Faculty Publication Series

No abstract provided.


The Activities Of The Education And Training Group Of The Analytical Division Of The Chemical Society, D. Thorburn Burns, Julian Tyson Jan 1979

The Activities Of The Education And Training Group Of The Analytical Division Of The Chemical Society, D. Thorburn Burns, Julian Tyson

Chemistry Department Faculty Publication Series

No abstract provided.


Temperature Dependent Spatial Order In Superfluid And Normal 4he, Robert Hallock, H. N. Robkoff, D. A. Ewen Jan 1979

Temperature Dependent Spatial Order In Superfluid And Normal 4he, Robert Hallock, H. N. Robkoff, D. A. Ewen

Robert Hallock

Measurements of the structure factor S(k) for 4He at constant density above and below Tλ are reported. The results show a clear loss of spatial order on cooling through Tλ. Application of the theory of Cummings, Hyland, and Rowlands to the data allows a measurement of the condensate fraction for He II.


Behavior Of Persistent Currents Under Conditions Of Strong Decay, Robert Hallock, D. T. Ekholm Jan 1979

Behavior Of Persistent Currents Under Conditions Of Strong Decay, Robert Hallock, D. T. Ekholm

Robert Hallock

We report observations of the decay of persistent currents of thin superfluid 4He films for which the superfluid velocity deviates strongly from the previously observed logt behavior. We present data which document the evolution of this behavior as a function of film thickness. The Iordanskii-Langer-Fisher theory does not accurately describe our observation


Recent Climatic Fluctuations Of The Canadian High Arctic And Their Significance For Glaciology, Raymond S. Bradley, John England Jan 1978

Recent Climatic Fluctuations Of The Canadian High Arctic And Their Significance For Glaciology, Raymond S. Bradley, John England

Raymond S Bradley

Various measures of the character of ablation season conditions in the Canadian High Arctic (north of 74°N) are discussed based on an analysis of daily climatic data from Alert, Eureka, Isachsen, Resolute, and Thule. Melting degree day totals appear to be the most useful index of "summer warmth." An abrupt change in the summer climate of the region occurred around 1963164. Various indices indicate a marked decrease in summer temperature after 1963. During the same period, annual precipitation in the north and northwest has increased. Glacier mass balance is strongly controlled by summer climate; in particular, annual melting degree day …


Former Ice Shelves In The Canadian High Arctic, John England, Raymond S. Bradley, G. H. Miller Jan 1978

Former Ice Shelves In The Canadian High Arctic, John England, Raymond S. Bradley, G. H. Miller

Raymond S Bradley

ABSTRACT. Moraines deposited by the outermost ice advance across Judge Daly Promontory, northeastern Ellesmere Island, reflect thin, topographically controlled ice lobes extending to sea-level. The termini of two ice lobes were investigated and both produced ice shelves where they flowed into isostatically depressed embayments along western Kennedy Channel. Morphological evidence for these ice shelves occurs at the entrance to these valleys where steeply descending lateral moraines become abruptly horizontal for 2 km. In addition, both the horizontal moraines and associated pro-glacial terraces are fossiliferous downvalley from the apparent grounding line. Based on the differences in elevation between the horizontal moraines …


Direct Observation Of Pulsed Third Sound Mass Displacement Waves In Unsaturated Superfluid 4he Films, Robert Hallock, J. S. Brooks, F. M. Ellis Jan 1978

Direct Observation Of Pulsed Third Sound Mass Displacement Waves In Unsaturated Superfluid 4he Films, Robert Hallock, J. S. Brooks, F. M. Ellis

Robert Hallock

We report direct observation of pulsed third-sound film thickness oscillations in unsaturated superfluid 4He films using a capacitance technique. Simultaneous measurements of accompanying temperature oscillations allow the first study of the relative amplitudes of these oscillations and the results are in reasonable agreement with the theory of Bergman although some discrepancies are noted.


Environmental Change And Cultural Change In The Eastern Canadian Arctic During The Last 5000 Years, R. G. Barry, Wendy H. Arundale, J. T. Andrews, Raymond S. Bradley Jan 1977

Environmental Change And Cultural Change In The Eastern Canadian Arctic During The Last 5000 Years, R. G. Barry, Wendy H. Arundale, J. T. Andrews, Raymond S. Bradley

Raymond S Bradley

Archaeological research suggests that cultural changes in the Canadian Arctic are closely linked to environmental changes. Current knowledge of postglacial climate and marine conditions in the eastern Canadian Arctic- an area demonstrably sensitive to small fluctuations in these conditions-is reviewed in the context of the prehistoric cultural sequence. Most of the major cultural events since 4500 BP appear to correlate well with the paleoclimatic conditions inferred from environmental data, although specific causal mechanisms cannot be documented. The expansions of Arctic Small Tool tradition (ASTt) and later of the Thule people seem to be related to warmer climatic conditions, whereas the …


Saturated Superfluid 4he Film Flow: Characteristic Oscillations Induced By Persistent Circulation, Robert Hallock, R. K. Galkiewicz Jan 1977

Saturated Superfluid 4he Film Flow: Characteristic Oscillations Induced By Persistent Circulation, Robert Hallock, R. K. Galkiewicz

Robert Hallock

We report observations of characteristic reservoir oscillations induced by persistent circulation in saturated 4He films for several different geometries. The shape of the oscillation structure appears to be in qualitative agreement with the predictions of Campbell. Within the constraints imposed by theoretical approximations and uncertainties in the experimental parameters, the quantitative agreement is satisfactory.


Experiments On The Attenuation Of Third Sound In Saturated Superfluid Helium Films, Robert Hallock, K. L. Telschow, R. K. Galkiewicz Dec 1976

Experiments On The Attenuation Of Third Sound In Saturated Superfluid Helium Films, Robert Hallock, K. L. Telschow, R. K. Galkiewicz

Robert Hallock

Upper limits of the attenuation of third sound in saturated superfluid 4He films have been measured in three separate experiments. Our observations at frequencies from 0.1 to 200 Hz indicate that the attenuation in these thick films is substantially lower than would be inferred from the only previous experiment done on saturated films. We observe the third-sound velocity to have the temperature dependence predicted by Bergman.


Secular Changes Of Precipitation In The Rocky Mountain States, Raymond S. Bradley May 1976

Secular Changes Of Precipitation In The Rocky Mountain States, Raymond S. Bradley

Raymond S Bradley

Long-term preCIpitation records from Montana, Idaho, Wyoming, Utah and western Colorado were obtained and carefully screened for missing data and station relocations. Each record was divided into five seasonal series and tested for homogeneity. Most of theunhomogeneous records were for the winter season, whereas there were fewest for summer and late summer seasons. Those seasonal records considered to be homogeneous were then used to examine the spatial variation of precipitation anomalies decade by decade (1891-1900, 1901-1910, etc.) from 1941-70 averages. Areas of statistically significant anomalies were identified. Generally, precipitation was high in the 1890's, 1910's and/or 1920's, 1940's and 1960's. …


Film Thinning In He Ii At Temperatures Above 1.1k, Robert Hallock, E. B. Flint Mar 1975

Film Thinning In He Ii At Temperatures Above 1.1k, Robert Hallock, E. B. Flint

Robert Hallock

We have made measurements of the velocity-dependent film thinning in saturated films of He II over the temperature range 1.1