WorldCat Identities

Carr, John S.

Works: 22 works in 45 publications in 1 language and 108 library holdings
Genres: Academic theses 
Roles: Author
Publication Timeline
Most widely held works by John S Carr
Field testing of a lightweight relocatable structure in a temperate environment by A Kao( Book )

4 editions published in 1985 in English and held by 60 WorldCat member libraries worldwide

This report described field tests of a commercially available, off-the-shelf, lightweight relocatable structure (LRS) system selected for possible military use in a theater of operations. A panelized system manufactured by Kelly Klosure, Inc. was selected to determine the constructibility, durability, an habitability of the building system. The first stage tests were conducted in a desert environment (Fort Irwin, CA) and stage II tests were conducted in a temperate environment (Fort Leonard Wood, MO). The results of stage I tests are documented in U.S. Army Constructibility of the building varies, depending on size. The tests confirm that the 20-ft-wide X 8-ft-high buildings can be erectd manually by unskilled troop labor using only hand tools. However, for 12-ft-high structure assembled using 4-X 8-ft panels, and for 12-ftu-high structures on elevated foundation/baseplates, a creane is need to help assembled components for the erection. Elevated foundation/baseplates greatly increase construction difficulty and contra and construction times. Keywords include: Buikdings; Light weight relocatable structures; Portable shelters; Ft. Leonard Wood; Temperate regions
Radioactive isotopes in mineral dressing research by England) Atomic Energy Research Establishment (Harwell( Book )

4 editions published in 1952 in Undetermined and English and held by 6 WorldCat member libraries worldwide

Evaluation of existing condition rating procedures for civil works structures and facilities by Enno Koehn( Book )

2 editions published in 1986 in English and held by 5 WorldCat member libraries worldwide

Time for training : Report of a survey of day care training needs in the Glasgow area by John S Carr( Book )

2 editions published in 1991 in English and held by 4 WorldCat member libraries worldwide

Tayside dementia services planning survey by John S Carr( Book )

1 edition published in 1992 in English and held by 3 WorldCat member libraries worldwide

Hot H2O Emission and Evidence for Turbulence in the Disk of a Young Star( )

2 editions published in 2004 in English and held by 3 WorldCat member libraries worldwide

We report on the detection and analysis of hot rovibrational H2O emission from SVS 13, a young stellar object previously known to have strong CO overtone band head emission. Modeling of the high-resolution infrared spectrum shows that the H2O emission is characterized by temperatures of 1500 K, significantly lower than the temperatures that characterize the CO band head emission. The widths of the H2O lines are also found to be smaller than those of the CO lines. We construct a disk model of the emission that reproduces the CO and H2O spectrum. In this model, the H2O lines originate at somewhat larger disk radii (0.3 AU) than the CO overtone lines (0.1 AU). We find that the H2O abundance is about a factor of 10 lower than the calculated chemical equilibrium abundance. Large, approximately transonic, local line broadening is required to fit the profile of the CO band head. If this velocity dispersion is identified with turbulence, it is of significant interest regarding the transport of angular momentum in disks. Large local broadening is also required in modeling CO overtone emission from other young stellar objects, suggesting that large turbulent velocities may be characteristic of the upper atmospheres of the inner disks of young stars
Gaseous Inner Disks( Book )

2 editions published in 2007 in English and held by 2 WorldCat member libraries worldwide

As the likely birthplaces of planets and an essential conduit for the buildup of stellar masses, inner disks are of fundamental interest in star and planet formation. Studies of the gaseous component of inner disks are of interest because of their ability to probe the dynamics, physical and chemical structure, and gas content of this region. We review the observational and theoretical developments in this field, highlighting the potential of such studies to, e.g., measure inner disk truncation radii, probe the nature of the disk accretion process, and chart the evolution in the gas content of disks. Measurements of this kind have the potential to provide unique insights on the physical processes governing star and planet formation
Stellar and Circumstellar Properties of the Pre-Main-Sequence Binary GV Tau From Infrared Spectroscopy( Book )

2 editions published in 2008 in English and held by 2 WorldCat member libraries worldwide

We report spatially resolved spectroscopy of both components of the low-mass pre-main-sequence binary GV Tau. High-resolution spectroscopy in the K and L bands is used to characterize the stellar properties of the binary and to explore the nature of the circumstellar environment. We find that the southern component, GV Tau S, is a radial velocity variable, possibly as a result of an unseen low-mass companion. The strong warm gaseous HCN absorption reported previously by Gibb and coworkers toward GV Tau S was not present during the epoch of our observations. Instead, we detect warm (500 K) molecular absorption with similar properties toward the northern infrared companion, GV Tau N. At the epoch of our observations, the absorbing gas toward GV Tau N was approximately at the radial velocity of the GV Tau molecular envelope, but it was redshifted with respect to the star by ~13 km s(exp-1). One interpretation of our results is that GV Tau N is also a binary and that most of the warm molecular absorption arises in a circumbinary disk viewed close to edge-on
The First Stellar Abundance Measurements in the Galactic Center: The M Supergiant IRS 7( Book )

2 editions published in 2000 in English and held by 2 WorldCat member libraries worldwide

The first measurement of the photospheric abundances in a star at the Galactic center are presented. A detailed abundance analysis of the Galactic center M2 supergiant IRS 7 was carried out using high-resolution near-infrared echelle spectra. The Fe abundance for IRS 7 was found to be close to solar, [Fe/H] = 0.02 +/- 0.13, and nearly identical to the Fe abundance we obtained for the nearby M supergiants alpha Ori and VV Cep. Analysis of the first and second overtone lines of CO was used to derive an effective temperature of 3600 +/- 230 K, a microturbulent velocity of 3.0 +/- 0.3 km s(exp -1), and a carbon abundance log e (C) = 7.78 +/- 0.13, or [C/H] = -0.77. In addition, we find a high depletion of 0.74 +/- 0.32 dex in O and an enhancement of 0.92 +/- 0.18 dex in N. These abundances are consistent with the dredge-up of CNO cycle products but require deep mixing in excess of that predicted by standard models for red supergiants. In light of our measured solar Fe abundance for IRS 7, we discuss other indicators of metallicity at the Galactic center, the interpretation of low-resolution near-infrared spectra of late-type giants and supergiants, including the need for caution in using such spectra as measures of metallicity, and the evolution of massive young stars at the Galactic center. We suggest the possibility that rapid stellar rotation is common for stars formed under conditions in the Galactic center, and that extra internal mixing induced by high rotation rates, rather than evolution at high metallicity, is the explanation for many of the unusual properties of the hot emission-line stars in the Galactic center
Gas at the Inner Disk Edge( Book )

2 editions published in 2007 in English and held by 2 WorldCat member libraries worldwide

Infrared molecular spectroscopy is a key tool for the observation of gas in the innermost region of disks around T Tauri stars. In this contribution, we examine how infrared spectroscopy of CO can be used to study the inner truncation region of disks around T Tauri stars. The inferred inner gas radii for T Tauri star disks are compared to the inner dust radii of disks, to the expectations of models for disk truncation, and to the orbital distribution of short-period extra-solar planets
High-Resolution Infrared Spectroscopy of Protoplanetary Disks( Book )

2 editions published in 2005 in English and held by 2 WorldCat member libraries worldwide

High-resolution spectroscopy at near and mid-infrared wavelengths can provide important and unique information about protoplanetary disks around young stars. In particular infrared molecular spectroscopy is a good diagnostic of gas in the planet-forming regions of disks within tilde 10 AU of the star. Data on the physical conditions gas content structure and chemistry of inner disks can be obtained through the analysis of velocity-resolved line profiles
The Revised elderly persons disability scale (REPDS) : applications training guide by John S Carr( Book )

1 edition published in 1997 in English and held by 2 WorldCat member libraries worldwide

From Stars to Superplanets: The Low-Mass Initial Mass Function in the Young Cluster IC 348( Book )

2 editions published in 2000 in English and held by 2 WorldCat member libraries worldwide

We investigate the low-mass population of the young cluster IC 348 down to the deuterium-burning limit, a fiducial boundary between brown dwarf and planetary mass objects, using a new and innovative method for the spectral classification of late-type objects. Using photometric indices, constructed from HST/NICMOS narrowband imaging, that measure the strength of the 1.9 micron water band, we determine the spectral type and reddening for every M-type star in the field, thereby separating cluster members from the interloper population. Due to the efficiency of our spectral classification technique, our study is complete from approximately 0.7 to 0.015 solar mass. The mass function derived for the cluster in this interval, dN/ d log M varies as M(exp 0.5), is similar to that obtained for the Pleiades, but appears significantly more abundant in brown dwarfs than the mass function for companions to nearby Sunlike stars. This provides compelling observational evidence for different formation and evolutionary histories for substellar objects formed in isolation versus as companions. Because our determination of the IMF is complete to very low masses, we can place interesting constraints on the role of physical processes such as fragmentation in the star and planet formation process and the fraction of dark matter in the Galactic halo that resides in substellar objects
Gas in the Terrestrial Planet Region of Disks: CO Fundamental Emission from T Tauri Stars( Book )

2 editions published in 2003 in English and held by 2 WorldCat member libraries worldwide

We report the results of a high-resolution spectroscopic survey for CO fundamental emission from T Tauri stars. CO fundamental emission is frequently detected, with the likely origin of the emission in the circumstellar disk. An initial assessment of the line profiles indicates that the emission region includes the equivalent of the terrestrial planet region of our solar system, a result that suggests the utility of CO fundamental emission as a probe of disks at planet formation distances. Since fundamental emission is detected frequently from both close binary and apparently single stars, it appears that both low column density regions, such as disk gaps, and temperature inversion regions in disk atmospheres can produce significant emission. The estimated excitation temperature of the emitting gas is unexpectedly warm for the disk radii that they appear to probe. Thus, the surface gaseous component of inner disks may be significantly warmer than the surface dust component. We also detect CO emission from a transitional T Tauri star. Because fundamental emission from CO and its isotopes is sensitive to a wide range of gas masses, CO fundamental emission may prove useful in measuring the residual gas content of dissipating disks. This may be an effective way to explore the gas dissipation timescale in inner disks and to thereby place constraints on the timescale for giant planet formation
Evidence for Residual Material in Accretion Disk Gaps: CO Fundamental Emission from the T Tauri Spectroscopic Binary DQ Tauri( Book )

2 editions published in 2001 in English and held by 2 WorldCat member libraries worldwide

We present the discovery of CO fundamental rovibrational emission from the classical T Tauri spectroscopic binary DQ Tau. The high-resolution infrared echelle spectra reveal emission lines from both the gamma = 1 and gamma = 2 vibrational levels with line widths of roughly 70 km s(exp -1). The average CO excitation temperature is approximately 1200 K. We model the spectra as arising from gas in Keplerian rotation about the center of mass of the binary. The disk model requires gas with an average surface density of 5x10(exp -4) g sq cm that extends outward to 0.5 plus or minus 0.1 AU and inward to at least 0.1 AU from the center of mass. The radial extent for the emitting gas is close to the predicted size of the gap in the DQ Tau accretion disk that is expected to be dynamically cleared by the binary. We interpret these results, and previous modeling of DQ TauSs spectral energy distribution, as evidence for a small amount (̃10(exp 10) M circle dot solar of diffuse material residing within the optically thin disk gap. Thus, dynamical clearing has not been completely efficient in the DQ Tau binary. We suggest that the material is associated with a flow from the circumbinary disk which feeds the ongoing accretion at the stellar surfaces
Stellar Iron Abundances at the Galactic Center( Book )

2 editions published in 2000 in English and held by 2 WorldCat member libraries worldwide

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 2.5 pc of the Galactic center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution K-band spectra, taken with CSHELL at the NASA Infrared Telescope Facility. We determine the iron abundance by detailed abundance analysis, performed with the spectral synthesis program MOOG. The mean [Fe/H] of the GC stars is determined to be near solar, [Fe/H]=+0.12 +/- 0.22. Our analysis is a differential analysis, as we have observed and applied the same analysis technique to 11 cool, luminous stars in the solar neighborhood with similar temperatures and luminosities as the GC stars. The mean [Fe/H] of the solar neighborhood comparison stars, [Fe/H] = 0.03 +/- 0.16, is similar to that of the GC stars. The width of the GC [Fe/H] distribution is found to be narrower than the width of the [Fe/H] distribution of Baade's window in the bulge but consistent with the width of the [Fe/H] distribution of giant and supergiant stars in the solar neighborhood
CO Fundamental Emission from V836 Tauri( Book )

2 editions published in 2008 in English and held by 2 WorldCat member libraries worldwide

We present high-resolution 4.7 micron CO fundamental spectroscopy of V836 Tau, a young star with properties that are between those of classical and weak T Tauri stars and which may be dissipating its circumstellar disk. We find that the CO line profiles of V836 Tau are unusual in that they are markedly double-peaked, even after correcting for stellar photospheric absorption in the spectrum. This suggests that the CO emission arises from a restricted range of disk radii (<0.5 AU), in contrast to the situation for most classical T Tauri stars, where the CO emission extends out to much larger radii (1 2AU). We discuss whether the outer radius of the emission in V836 Tau results from the physical truncation of the disk or an excitation effect. We also explore how either of these hypotheses may bear on our understanding of disk dissipation in this system
Studies of contact angles on oxidized copper minerals by John S Carr( )

2 editions published in 1948 in English and held by 2 WorldCat member libraries worldwide

"Effective flotation of an ore is the result of several factors: selection of suitable reagents; the proper combination of reagents, processing conditions of the operation proper such as time intervals involved and the machinery used. To focus the investigation on a specific field it was decided to investigate in some detail the behaviour of the more popular collectors toward oxidized copper minerals. This investigation was carried out chiefly by applying contact-angle measurements as obtained with the various collectors on the basic carbonate and oxide copper minerals. This basic information was desirable before carrying out actual flotation tests. There was little information of this kind available in published literature. The contact angles for ethyl and amyl xanthates, some mercaptans and sodium oleate were determined. The effect of sulphidization with sodium sulphide of the oxidized minerals in conjunction with the sulphydrate collectors, was investigated. The test work indicated that contrary to the experience with sulphide minerals, the contact angle for a given collector was influenced by the mineral used, carbonates as compared with the oxide, also a higher concentration of collector was necessary to yield contact as compared with sulphide minerals"--Introduction, leaves 1-2
An evaluation of the design of specialist residential care units for people with dementia by M Kelly( Book )

2 editions published in 1995 in English and held by 1 WorldCat member library worldwide

Evidence for residual material in accretion disk gaps : CO fundamental emission from the T Tauri spectroscopic binary DQ Tau by John S Carr( Book )

1 edition published in 2000 in English and held by 1 WorldCat member library worldwide

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English (39)