264 research outputs found
HEAT TRANSFER TO A MIST FLOW. Technical Report No. 5
An experimental and analytical study was made of the heat-transfer characteristics of a mist flow of steam and water droplets flowing vertically upward in a round tube. A simplified analytical model, based on momentum, mass, and energy considerations, was developed which shows qualitatively that severe temperature fluctuations are characteristic of such flows under constant-wall heat-flux conditions. The experimental data showed that the analytical model gave a fairly accurate qualitative description of the tube-wall temperature variation with length. The analysis of the data seemed to indicate that the assumptions of equilibrium between phases and constant values for the mass- transfer coefficient for droplets were incorrect. (auth
Biological remodelling: Stationary energy, configurational change, internal variables and dissipation
Remodelling is defined as an evolution of microstructure or variations in the
configuration of the underlying manifold. The manner in which a biological
tissue and its subsystems remodel their structure is treated in a continuum
mechanical setting. While some examples of remodelling are conveniently
modelled as evolution of the reference configuration (Case I), others are more
suited to an internal variable description (Case II). In this paper we explore
the applicability of stationary energy states to remodelled systems. A
variational treatment is introduced by assuming that stationary energy states
are attained by changes in microstructure via one of the two mechanisms--Cases
I and II. An example is presented to illustrate each case. The example
illustrating Case II is further studied in the context of the thermodynamic
dissipation inequality.Comment: 24 pages, 4 figures. Replaced version has corrections to typos in
equations, and the corresponding correct plot of the solution--all in Section
AN INVESTIGATION OF CERTAIN THERMODYNAMIC AND TRANSPORT PROPERTIES OF WATER AND WATER VAPOR IN THE CRITICAL REGION
An accurate knowledge of thermodynamic and transport properties of water in the critical region is required in order to analyze future power cycles, nuclear reactor configurations, and other types of heat transfer apparatus. Preliminnry investigations showed that this was rot possible with presently existing tabulations. Experimentel data from volumetric viscosity and thermal conductivity studies were therefore selected and retabulated. Smoothings of these data are described and, for the first time, a tabulation at close intervals of pressure and temperature of the volumetric data is possible for steam in the critical region. A graphical presentation is given of volumetric data from 700 to 750 deg F. An important result of this study was that excellent agreement existed between the many P-V-T measurements for this substance even though some of the data was obtained many years ago. Differences occurring between the tabulated data of various steam tables were found to arise from the use of inexact equations of state or interpolation techniques rather than from faulty primary data. New P-V-T data were derived from measurements of other investigators, by a graphical technique and it is estimated that it yielded pressure values accurate to some five parts in ten thousand except in the subcooled liquid region (for specific volumes below 0.040 ftsup 3/lb), where the uncertainty may be some twenty parts in ten thousand. Study of the existing thermal conductivity and viscosity data suggests that the Russian work is the most consistent. However, it appears that the empirical equations proposed for interpolation do not adequately represent the data in the critical region. No attempt has been made to derive thermodynamic functions or to analyze the transport data. (auth
A Preliminary Report on Unique Hail and Tornadic Storm Observations in Central Illinois and Eastern Indiana on 3 April 1974
published or submitted for publicationis peer reviewedOpe
The Ursinus Weekly, October 30, 1975
16 U.C. seniors named to Who\u27s who • Prof. presides • U.C. Founder\u27s Day to honor church • Dr. Isaac Asimov named speaker • Editorial: Ursinus\u27 infirmary is ailing! • Letters to the editor: Soccer regrets; Speaking out; Resident vs. day; An open letter to Richard J. Whatley • Newest P.E. prof • Visitor notes strange customs • Renowned sculptor presents project • Forum review: Lisa A. Richette speaks at Ursinus • Ursinus wins! • We\u27re no. 1! • Between inningshttps://digitalcommons.ursinus.edu/weekly/1044/thumbnail.jp
Using sparse categorical principal components to estimate asset indices: new methods with an application to rural southeast asia
PRIFPRI3; DCA; ISI; 4 Transforming Agricultural and Rural EconomiesDSG
Spontaneous Basilar Membrane Oscillation and Otoacoustic Emission at 15 kHz in a Guinea Pig
A spontaneous otoacoustic emission (SOAE) measured in the ear canal of a guinea pig was found to have a counterpart in spontaneous mechanical vibration of the basilar membrane (BM). A spontaneous 15-kHz BM velocity signal was measured from the 18-kHz tonotopic location and had a level close to that evoked by a 14-kHz, 15-dB SPL tone given to the ear. Lower-frequency pure-tone acoustic excitation was found to reduce the spontaneous BM oscillation (SBMO) while higher-frequency sound could entrain the SBMO. Octave-band noise centered near the emission frequency showed an increased narrow-band response in that frequency range. Applied pulses of current enhanced or suppressed the oscillation, depending on polarity of the current. The compound action potential (CAP) audiogram demonstrated a frequency-specific loss at 8 and 12Â kHz in this animal. We conclude that a relatively high-frequency spontaneous oscillation of 15Â kHz originated near the 15-kHz tonotopic place and appeared at the measured BM location as a mechanical oscillation. The oscillation gave rise to a SOAE in the ear canal. Electric current can modulate level and frequency of the otoacoustic emission in a pattern similar to that for the observed mechanical oscillation of the BM.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41384/1/10162_2004_Article_4045.pd
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