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1

Transferable Output ASCII Data (TOAD) File Format Description.  

National Technical Information Service (NTIS)

Described is a format for writing ASCII data on a file to facilitate its transfer from one computer system to another. The TOAD format conforms to all ANSI FORTRAN 77 standards. There are two advantages in using the TOAD format. First, TOAD files are of t...

B. Bingel D. Hammond

1987-01-01

2

File-Format Program For Transferable Output ASCII Data  

NASA Technical Reports Server (NTRS)

TOAD utilities machine-independent and require minimal central memory. Transferable Output ASCII Data (TOAD) file-format computer program facilitates transfer of data files from one computer installation to another. TOAD files preferred type and record length, easy to edit, read, and write on magnetic tape or transfer across communications networks. Applications programs write TOAD files directly and conform to all ANSI FORTRAN 77 standards.

Bingle, Bradford

1988-01-01

3

Transferable Output ASCII Data (TOAD) file format description  

NASA Technical Reports Server (NTRS)

Described is a format for writing ASCII data on a file to facilitate its transfer from one computer system to another. The TOAD format conforms to all ANSI FORTRAN 77 standards. There are two advantages in using the TOAD format. First, TOAD files are of the preferred type and record length to make them easy to edit, read from and write on magnetic tape, or transfer across communications networks. Secondly, application programs, using the TOAD format to write computational results, are more portable and the answer files easier to postprocess. TOAD utility software is listed in an appendix.

Bingel, Bradford; Hammond, Dana

1987-01-01

4

A quantitative model of ground-water flow during formation of tabular sandstone uranium deposits  

Microsoft Academic Search

Tabular sandstone uranium deposits constitute the largest uranium resource type in the United States. A major point of contention has been the nature and direction of the groundwater flow. This paper presents a quantitative simulation of regional ground-water flow during uranium deposition in the Westwater Canyon Member and Jackpile Sandstone Member of the Upper Jurassic Morrison Formation in the San

Sanford

2009-01-01

5

Transferable Output ASCII Data (TOAD) gateway: Version 1.0 user's guide  

NASA Technical Reports Server (NTRS)

The Transferable Output ASCII Data (TOAD) Gateway, release 1.0 is described. This is a software tool for converting tabular data from one format into another via the TOAD format. This initial release of the Gateway allows free data interchange among the following file formats: TOAD; Standard Interface File (SIF); Program to Optimize Simulated Trajectories (POST) input; Comma Separated Value (TSV); and a general free-form file format. As required, additional formats can be accommodated quickly and easily.

Bingel, Bradford D.

1991-01-01

6

Formation of tabular single-domain magnetite induced by Geobacter metallireducens GS-15.  

PubMed

Distinct morphological characteristics of magnetite formed intracellularly by magnetic bacteria (magnetosome) are invoked as compelling evidence for biological activity on Earth and possibly on Mars. Crystals of magnetite produced extracellularly by a variety of bacteria including Geobacter metallireducens GS-15, thermophilic bacteria, and psychrotolerant bacteria are, however, traditionally not thought to have nearly as distinct morphologies. The size and shape of extracellular magnetite depend on the culture conditions and type of bacteria. Under typical CO(2)-rich culture conditions, GS-15 is known to produce superparamagnetic magnetite (crystal diameters of approximately <30 nm). In the current study, we were able to produce a unique form of tabular, single-domain magnetite under nontraditional (low-CO(2)) culture conditions. This magnetite has a distinct crystal habit and magnetic properties. This magnetite could be used as a biosignature to recognize ancient biological activities in terrestrial and extraterrestrial environments and also may be a major carrier of the magnetization in natural sediments. PMID:15525704

Vali, Hojatollah; Weiss, Benjamin; Li, Yi-Liang; Sears, S Kelly; Kim, Soon Sam; Kirschvink, Joseph L; Zhang, Chuanlun L

2004-11-16

7

Geochemical properties of the water-snow-ice complexes in the area of Shokalsky glacier, Novaya Zemlya, in relation to tabular ground-ice formation  

NASA Astrophysics Data System (ADS)

Tabular (massive) ground ice in periglacial areas of the Russian Arctic (Barents and Kara Sea coasts) is considered to be a remnant of past glacial epochs and is thus used as proof of the glacial extent. In this paper, we argue that the origin of these tabular ice bodies, which can be used as archives of specific climatic conditions and periglacial environments, is intra-sedimentary (migration/intrusion). The objective of this study is to establish geochemical benchmarks describing the ice formation from atmospheric moisture and compare them with geochemical data of tabular ground ice. Shokalsky glacier on Novaya Zemlya (NZ), on the east coast of the Barents Sea, was chosen as a possible moisture source for the formation of tabular ground ice at the key section 'Shpindler' on Yugorsky peninsula, on the south coast of the Kara Sea. Tabular ice in the Shpindler section was compared to the Shokalsky glacier ice in both isotope/geochemical and structural aspects. In general, the hydrochemical properties of glacier ice at NZ and ground ice from Shpindler are closely correlated, while stable-isotope, microelemental and microbiological properties are substantially different. It was concluded that glacier ice most likely participated in the formation of tabular ground ice, but only as a source of refrozen meltwater.

Leibman, M. O.; Arkhipov, S. M.; Perednya, D. D.; Savvichev, A. S.; Vanshtein, B. G.; Hubberten, H. W.

8

SEGY to ASCII: Conversion and Plotting Program  

USGS Publications Warehouse

This report documents a computer program to convert standard 4 byte, IBM floating point SEGY files to ASCII xyz format. The program then optionally plots the seismic data using the GMT plotting package. The material for this publication is contained in a standard tar file (of99-126.tar) that is uncompressed and 726 K in size. It can be downloaded by any Unix machine. Move the tar file to the directory you wish to use it in, then type 'tar xvf of99-126.tar' The archive files (and diskette) contain a NOTE file, a README file, a version-history file, source code, a makefile for easy compilation, and an ASCII version of the documentation. The archive files (and diskette) also contain example test files, including a typical SEGY file along with the resulting ASCII xyz and postscript files. Requirements for compiling the source code into an executable are a C++ compiler. The program has been successfully compiled using Gnu's g++ version 2.8.1, and use of other compilers may require modifications to the existing source code. The g++ compiler is a free, high quality C++ compiler and may be downloaded from the ftp site: ftp://ftp.gnu.org/gnu Requirements for plotting the seismic data is the existence of the GMT plotting package. The GMT plotting package may be downloaded from the web site: http://www.soest.hawaii.edu/gmt/

Goldman, Mark R.

1999-01-01

9

Geochemical properties of the water-snow-ice complexes in the area of Shokalsky glacier, Novaya Zemlya, in relation to tabular ground-ice formation  

Microsoft Academic Search

Tabular (massive) ground ice in periglacial areas of the Russian Arctic (Barents and Kara Sea coasts) is considered to be a remnant of past glacial epochs and is thus used as proof of the glacial extent. In this paper, we argue that the origin of these tabular ice bodies, which can be used as archives of specific climatic conditions and

M. O. Leibman; S. M. Arkhipov; D. D. Perednya; A. S. Savvichev; B. G. Vanshtein; H. W. Hubberten

2005-01-01

10

AstroAsciiData: Table Handling in Python  

NASA Astrophysics Data System (ADS)

Tabulated character strings and numbers in text files are one of the most widespread data exchange format in astronomy and science in general. Presented here is version 1.0 of the Python module AstroAsciiData. This module is a lightweight framework that provides convenient access to table data and supports the common chore of writing scripts to read, manipulate and write the data. Well-formed tables are automatically parsed and transformed into objects, which allows a very convenient and intuitive data manipulation. Version 1.0 of the AstroAsciiData module uses metadata stored in the header of the ubiquitous SExtractor output catalogues and provides transformations to other data formats such as FITS or HTML.

Haase, J.; Kümmel, M.

2007-10-01

11

AstroAsciiData: Table Handling in Python  

Microsoft Academic Search

Tabulated character strings and numbers in text files are one of the most widespread data exchange format in astronomy and science in general. Presented here is version 1.0 of the Python module AstroAsciiData. This module is a lightweight framework that provides convenient access to table data and supports the common chore of writing scripts to read, manipulate and write the

J. Haase; M. Kümmel

2007-01-01

12

SEGY to ASCII Conversion and Plotting Program 2.0  

USGS Publications Warehouse

INTRODUCTION SEGY has long been a standard format for storing seismic data and header information. Almost every seismic processing package can read and write seismic data in SEGY format. In the data processing world, however, ASCII format is the 'universal' standard format. Very few general-purpose plotting or computation programs will accept data in SEGY format. The software presented in this report, referred to as SEGY to ASCII (SAC), converts seismic data written in SEGY format (Barry et al., 1975) to an ASCII data file, and then creates a postscript file of the seismic data using a general plotting package (GMT, Wessel and Smith, 1995). The resulting postscript file may be plotted by any standard postscript plotting program. There are two versions of SAC: one version for plotting a SEGY file that contains a single gather, such as a stacked CDP or migrated section, and a second version for plotting multiple gathers from a SEGY file containing more than one gather, such as a collection of shot gathers. Note that if a SEGY file has multiple gathers, then each gather must have the same number of traces per gather, and each trace must have the same sample interval and number of samples per trace. SAC will read several common standards of SEGY data, including SEGY files with sample values written in either IBM or IEEE floating-point format. In addition, utility programs are present to convert non-standard Seismic Unix (.sux) SEGY files and PASSCAL (.rsy) SEGY files to standard SEGY files. SAC allows complete user control over all plotting parameters including label size and font, tick mark intervals, trace scaling, and the inclusion of a title and descriptive text. SAC shell scripts create a postscript image of the seismic data in vector rather than bitmap format, using GMT's pswiggle command. Although this can produce a very large postscript file, the image quality is generally superior to that of a bitmap image, and commercial programs such as Adobe Illustrator? can manipulate the image more efficiently.

Goldman, Mark R.

2005-01-01

13

Transferable Output ASCII Data (TOAD) editor version 1.0 user's guide  

NASA Technical Reports Server (NTRS)

The Transferable Output ASCII Data (TOAD) editor is an interactive software tool for manipulating the contents of TOAD files. The TOAD editor is specifically designed to work with tabular data. Selected subsets of data may be displayed to the user's screen, sorted, exchanged, duplicated, removed, replaced, inserted, or transferred to and from external files. It also offers a number of useful features including on-line help, macros, a command history, an 'undo' option, variables, and a full compliment of mathematical functions and conversion factors. Written in ANSI FORTRAN 77 and completely self-contained, the TOAD editor is very portable and has already been installed on SUN, SGI/IRIS, and CONVEX hosts.

Bingel, Bradford D.; Shea, Anne L.; Hofler, Alicia S.

1991-01-01

14

Bit-Parallel ASCII Code Artificial Numeric Keypad.  

National Technical Information Service (NTIS)

Seven integrated circuits and a voltage regulator are combined with twelve reed relays to allow the ASCII encoded numerals 0 through 9 and characters ''.'' and R or S to momentarily close switches to an applications device, simulating keypad switch closur...

G. M. Hale

1981-01-01

15

Chapter 6. Tabular data and graphical images in support of the U.S. Geological Survey National Oil and Gas Assessment-East Texas basin and Louisiana-Mississippi salt basins provinces, Jurassic Smackover interior salt basins total petroleum system (504902), Travis Peak and Hosston formations.  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on the CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Geological Survey (U.S.)

2006-01-01

16

Comparative Analysis of ASCII and XML Logging Systems.  

National Technical Information Service (NTIS)

This research compares XML and ASCII based event logging systems in terms of their storage and processing efficiency. XML has been an emerging technology, even for security. Therefore, it is researched as a logging system with the mitigation of its verbos...

E. Hanington

2010-01-01

17

Graphic and tabular expressions of Bayes' theorem.  

PubMed

Bayes' theorem, as applied to the interpretation of diagnostic tests, is reexpressed as a two-step transformation. This allows for the construction of graphic and tabular expressions of this important principle. PMID:3574019

Benish, W A

1987-01-01

18

Taiwan Ascii and Idl_save Data Archives (AIDA) for THEMIS  

NASA Astrophysics Data System (ADS)

THEMIS (Time History of Events and their Macroscopic Interactions during Substorms) is a satellite mission that aims to determine where and how substorms are triggered. The space research team in Taiwan has been involved in data promotion and scientific research. Taiwan Ascii and Idl_save Data Archives (AIDA) for THEMIS is the main work of the data promotion. Taiwan AIDA is developed for those who are not familiar with the Interactive Data Language (IDL) data analysis and visualization software, and those who have some basic IDL concepts and techniques and want more flexibilities in reading and plotting the THEMIS data. Two kinds of data format are stored in Taiwan AIDA: one is ASCII format for most users and the other is IDL SAVE format for IDL users. The public can download THEMIS data in either format through the Taiwan AIDA web site, http://themis.ss.ncu.edu.tw/e_data_download.php. Taiwan AIDA provides (1) plasma data including number density, average temperature, and velocity of ions and electrons, (2) magnetic field data, and (3) state information including the position and velocity of five THEMIS probes. On the Taiwan AIDA web site there are two data-downloading options. The public can download a large amount of data for a particular instrument in the FTP equivalent option; the public can also download all the data for a particular date in the Data Search option.

Lee, B.; Hsieh, W.; Shue, J.; Angelopoulos, V.; Glassmeier, K. H.; McFadden, J. P.; Larson, D.

2008-12-01

19

A Retrofit Network Intrusion Detection System for MODBUS RTU and ASCII Industrial Control Systems  

Microsoft Academic Search

MODBUS RTU\\/ASCII Snort is software to retrofit serial based industrial control systems to add Snort intrusion detection and intrusion prevention capabilities. This article discusses the need for such a system by describing 4 classes of intrusion vulnerabilities (denial of service, command injection, response injection, and system reconnaissance) which can be exploited on MODBUS RTU\\/ASCII industrial control systems. The article provides

Thomas Morris; Rayford Vaughn; Yoginder Dandass

2012-01-01

20

A heuristic block coordinate descent approach for controlled tabular adjustment  

Microsoft Academic Search

One of the main concerns of national statistical agencies (NSAs) is to publish tabular data. NSAs have to guarantee that no private information from specific respondents can be disclosed from the released tables. The purpose of the statistical disclosure control field is to avoid such a leak of private information. Most protection techniques for tabular data rely on the formulation

José A. González; Jordi Castro

2011-01-01

21

Users' guide for the tabular display report generator program (TABDIS)  

NASA Technical Reports Server (NTRS)

The tabular display report generator (TABDIS) program is described. The program functions as a document generation tool that provides tabular displays of data stored on a data file which has been generated by a user program. The main features of the program are outlined and all necessary inputs are detailed.

Braley, D. M.

1980-01-01

22

Abstraction Based Automated Test Generation from Formal Tabular Requirements Specifications  

Microsoft Academic Search

\\u000a We propose an automated approach for generating tests from formal tabular requirements specifications, such as SCR specifications.\\u000a The technique is based on counterexample guided abstraction refinement and the use of SMT solving. Moreover, in order to effectively\\u000a perform automated test generation, we take advantage of particular characteristics of tabular requirements descriptions to\\u000a aid the abstraction and abstraction refinement processes. The

Renzo Degiovanni; Pablo Ponzio; Nazareno Aguirre; Marcelo Frias

23

Tabular Interface for Automated Verification of Event-Based Dialogs.  

National Technical Information Service (NTIS)

In this report, we investigate the feasibility of a tabular interface for the specification and analysis of event-based dialogues. These dialogues are used to define high-level descriptions of interactive systems, and they are based on Olsen's Proposition...

H. M. Wang G. Abowd

1994-01-01

24

Satellite Monitoring of Giant Tabular Icebergs (Abstract Only).  

National Technical Information Service (NTIS)

A summary of a study reporting the monitoring of several giant tabular icebergs that have recently broken off the southern ice shelves is presented. Geosat radar altimetry is used to produce a contour map of the ice shelf before and after the calving of t...

S. Laxon C. G. Rapley G. Davies

1992-01-01

25

Consistent thermodynamic derivative estimates for tabular equations of state  

Microsoft Academic Search

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce

Gary A. Dilts

2006-01-01

26

37 CFR 1.824 - Form and format for nucleotide and/or amino acid sequence submissions in computer readable form.  

Code of Federal Regulations, 2010 CFR

...Terminator: ASCII Carriage Return plus ASCII Line Feed. (4) Compact disc: Format: ISO 9660 or High Sierra Format. (5) Magneto Optical Disk: Size/Storage Specifications: 5.25 inch, 640 Mb. (d) Computer readable forms that are submitted...

2009-07-01

27

MCNP/X TRANSPORT IN THE TABULAR REGIME  

SciTech Connect

The authors review the transport capabilities of the MCNP and MCNPX Monte Carlo codes in the energy regimes in which tabular transport data are available. Giving special attention to neutron tables, they emphasize the measures taken to improve the treatment of a variety of difficult aspects of the transport problem, including unresolved resonances, thermal issues, and the availability of suitable cross sections sets. They also briefly touch on the current situation in regard to photon, electron, and proton transport tables.

HUGHES, H. GRADY [Los Alamos National Laboratory

2007-01-08

28

From tabular to rhombohedral dolomite crystals in Zechstein 2 dolostones from Scharzfeld (SW Harz/Germany): A case study with combined CL and EBSD investigations  

NASA Astrophysics Data System (ADS)

Tabular dolomite crystals found within dolomite rhombs have been investigated by cathodoluminescence (CL) microscopy and spectroscopy combined with electron backscatter diffraction (EBSD) for the first time. The dolomites formed in the Upper Permian Stassfurt Carbonate Ca2 at the southern margin of the German/Polish Zechstein Basin. Cathodoluminescence petrography of the dolostone succession revealed that the dolomites developed in four phases. Electron backscatter diffraction analysis reveals tabular crystal growth during the two first generations, while the last two generations are characterized by rhombohedral crystal shapes. The tabular dolomite cement crystals and their microcrystalline equivalents in matrix and components have a stoichiometric composition with good to very good lattice ordering. Manganese and iron contents of the tabular crystals are low and their carbon and oxygen isotope composition confirms an early diagenetic dolomite formation under marine-evaporitic conditions from precursor carbonates of Upper Permian age. CL spectroscopy reveals that the tabular dolomite generation 1 has a very high percentage of Mn 2+ on the Ca lattice position which results in a visually yellowish-green CL emission. Although relatively increased Mn 2+ contents at the Ca lattice position appear to be rather common in evaporitic dolomites the combination of a tabular crystal shape and a preferred input of Mn 2+ at the Ca lattice position is a remarkable phenomenon. As tabular dolomite crystals so far are exclusively reported from evaporitic diagenetic settings they could be the result of a high Mg/Ca ratio which blocks c-axis orientated growth of dolomite crystal. The occurrence of well ordered dolomite of which the geochemical zoning can be studied in such detail is rare for the earliest, synsedimentary stages of dolomite formation in marine environments, because these early stages commonly consist of not or badly ordered Ca-dolomites. A primary geochemical zoning of such dolomite usually gets lost during stabilisation and transformation to better ordering and stoichiometry.

Gillhaus, Axel; Richter, Detlev K.; Götte, Thomas; Neuser, Rolf D.

2010-07-01

29

Chapter 2: Tabular Data and Graphical Images in Support of the U.S. Geological Survey National Oil and Gas Assessment - The Wind River Basin Province  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on this CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files) because of the number and variety of platforms and software available.

Klett, T. R.; Le, P. A.

2007-01-01

30

CAP: A Computer Code for Generating Tabular Thermodynamic Functions from NASA Lewis Coefficients  

NASA Technical Reports Server (NTRS)

For several decades the NASA Glenn Research Center has been providing a file of thermodynamic data for use in several computer programs. These data are in the form of least-squares coefficients that have been calculated from tabular thermodynamic data by means of the NASA Properties and Coefficients (PAC) program. The source thermodynamic data are obtained from the literature or from standard compilations. Most gas-phase thermodynamic functions are calculated by the authors from molecular constant data using ideal gas partition functions. The Coefficients and Properties (CAP) program described in this report permits the generation of tabulated thermodynamic functions from the NASA least-squares coefficients. CAP provides considerable flexibility in the output format, the number of temperatures to be tabulated, and the energy units of the calculated properties. This report provides a detailed description of input preparation, examples of input and output for several species, and a listing of all species in the current NASA Glenn thermodynamic data file.

Zehe, Michael J.; Gordon, Sanford; McBride, Bonnie J.

2001-01-01

31

CAP: A Computer Code for Generating Tabular Thermodynamic Functions from NASA Lewis Coefficients. Revised  

NASA Technical Reports Server (NTRS)

For several decades the NASA Glenn Research Center has been providing a file of thermodynamic data for use in several computer programs. These data are in the form of least-squares coefficients that have been calculated from tabular thermodynamic data by means of the NASA Properties and Coefficients (PAC) program. The source thermodynamic data are obtained from the literature or from standard compilations. Most gas-phase thermodynamic functions are calculated by the authors from molecular constant data using ideal gas partition functions. The Coefficients and Properties (CAP) program described in this report permits the generation of tabulated thermodynamic functions from the NASA least-squares coefficients. CAP provides considerable flexibility in the output format, the number of temperatures to be tabulated, and the energy units of the calculated properties. This report provides a detailed description of input preparation, examples of input and output for several species, and a listing of all species in the current NASA Glenn thermodynamic data file.

Zehe, Michael J.; Gordon, Sanford; McBride, Bonnie J.

2002-01-01

32

Summer Decay Processes in a Large Tabular Iceberg  

NASA Astrophysics Data System (ADS)

Summer Decay Processes in a Large Tabular Iceberg Peter Wadhams (1), Till J W Wagner(1) and Richard Bates(2) (1) Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK (2) Scottish Oceans Institute, School of Geography and Geosciences, University of St Andrews, St. Andrews, Scotland KY16 9AL We present observational results from an experiment carried out during July-August 2012 on a giant grounded tabular iceberg off Baffin Island. The iceberg studied was part of the Petermann Ice Island B1 (PIIB1) which calved off the Petermann Glacier in NW Greenland in 2010. Since 2011 it has been aground in 100 m of water on the Baffin Island shelf at 69 deg 06'N, 66 deg 06'W. As part of the project a set of high resolution GPS sensors and tiltmeters was placed on the ice island to record rigid body motion as well as flexural responses to wind, waves, current and tidal forces, while a Waverider buoy monitored incident waves and swell. On July 31, 2012 a major breakup event was recorded, with a piece of 25,000 sq m surface area calving off the iceberg. At the time of breakup, GPS sensors were collecting data both on the main berg as well as on the newly calved piece, while two of us (PW and TJWW) were standing on the broken-out portion which rose by 0.6 m to achieve a new isostatic equilibrium. Crucially, there was no significant swell at the time of breakup, which suggests a melt-driven decay process rather than wave-driven flexural break-up. The GPS sensors recorded two disturbances during the hour preceding the breakup, indicative of crack growth and propagation. Qualitative observation during the two weeks in which our research ship was moored to, or was close to, the ice island edge indicates that an important mechanism for summer ablation is successive collapses of the overburden from above an unsupported wave cut, which creates a submerged ram fringing the berg. A model of buoyancy stresses induced by such rams indicates that they may have the capability through their moment arm of breaking off moderate-sized bergs, which may be the mechanism through which our smaller berg calved.

Wadhams, P.; Wagner, T. M.; Bates, R.

2012-12-01

33

Log ASCII Standard (LAS) Files for Geophysical (Gamma Ray) Wireline Well Logs and Their Application to Geologic Cross Section C-C' Through the Central Appalachian Basin  

USGS Publications Warehouse

U.S. Geological Survey (USGS) regional geologic cross section C-C' (Ryder and others, 2008) displays key stratigraphic intervals in the central Appalachian basin. For this cross section, strata were correlated by using descriptions of well cuttings and gamma ray well log traces. This report summarizes the procedures used to convert gamma ray curves on paper well logs to the digital Log ASCII (American Standard Code for Information Interchange) Standard (LAS) format using the third-party software application Neuralog. The procedures could be used with other geophysical wireline logs also. The creation of digital LAS files from paper well logs by using Neuralog is very helpful, especially when dealing with older logs with limited or nonexistent digital data. The LAS files from the gamma ray logs of 11 wells used to construct cross section C-C' are included in this report. They may be downloaded from the index page as a single ZIP file.

Trippi, Michael H.; Crangle, Robert D., Jr.

2009-01-01

34

Geosites inventory of the northwestern Tabular Middle Atlas of Morocco  

NASA Astrophysics Data System (ADS)

Across the northwestern Tabular Middle Atlas of Morocco there are many examples of landscapes, rocks and fossils that provide key evidence of a particular moment or period in Earth history. Such Earth heritage sites are important for educating the general public in environmental matters. They also serve as tools for demonstrating sustainable development and for illustrating methods of site conservation as well as remembering that rocks, minerals, fossils, soils, landforms form an integral part of the natural world. The significance of certain sites for aesthetic or tourism reasons is obvious. There are numerous geosites, which could contribute to effective exploitation of geotourism, often in conjunction with ecotourism. The strategy employed to such sites involves close consultation with all communities in the vicinity of the respective geosite and is not only aimed at tourism and education, but also at sustainable improvement of the infrastructure of the people of this area. Geological heritage sites, properly managed, can generate employment and new economic activities, especially in regions in need of new or additional sources of income.

El Wartiti, Mohamed; Malaki, Amina; Zahraoui, Mohamed; El Ghannouchi, Abdelilah; di Gregorio, Felice

2008-07-01

35

Consistent thermodynamic derivative estimates for tabular equations of state  

NASA Astrophysics Data System (ADS)

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. The consistency condition is important for the computation of various dimensionless parameters of an EOS that may involve derivatives of up to second order which are important for the development of more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a table interface based on the tuned regression method, which is derived from a constrained local least-squares regression technique. It is applied to several SESAME EOS showing how the consistency and stability conditions can be satisfied to round-off while computing first and second derivatives with demonstrated second-order convergence. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the method is apparently two orders of magnitude slower, due to the fact that every evaluation requires solving an 11-dimensional nonlinear system. Application is made to the computation of the fundamental derivative.

Dilts, Gary A.

2006-06-01

36

Consistent thermodynamic derivative estimates for tabular equations of state.  

PubMed

A valid fluid equation of state (EOS) must satisfy the thermodynamic conditions of consistency (derivation from a free energy) and stability (positive sound speed squared). Numerical simulations of compressible fluid flow for realistic materials require a tabular EOS, but typical software interfaces to such tables based on polynomial or rational interpolants may enforce the stability conditions, but do not enforce the consistency condition and its derivatives. The consistency condition is important for the computation of various dimensionless parameters of an EOS that may involve derivatives of up to second order which are important for the development of more sensitive artificial viscosities and Riemann solvers that accurately model shock structure in regions near phase transitions. We describe a table interface based on the tuned regression method, which is derived from a constrained local least-squares regression technique. It is applied to several SESAME EOS showing how the consistency and stability conditions can be satisfied to round-off while computing first and second derivatives with demonstrated second-order convergence. An improvement of 14 orders of magnitude over conventional derivatives is demonstrated, although the method is apparently two orders of magnitude slower, due to the fact that every evaluation requires solving an 11-dimensional nonlinear system. Application is made to the computation of the fundamental derivative. PMID:16907020

Dilts, Gary A

2006-06-01

37

A Study of Graphical and Tabular Displays and Their Interaction with Environmental Complexity  

Microsoft Academic Search

Since most interactive systems use either graphical or tabular displays, this experiment contrasts the effectiveness of the two displays in making the production scheduling decision in low and intermediate levels of environmental complexity. The study concludes that tabular aids outperform the graphical aids in environments with low complexity, replicating an earlier study. In intermediate complexity environments, the graphical aids outperform

William Remus

1987-01-01

38

Fast Registration of Tabular Document Images Using the Fourier-Mellin Transform  

Microsoft Academic Search

A new technique is presented for quickly identifying global affine transformations applied to tabular document images, and to correct for those transformations. This technique, based on the Fourier-Mellin transform, is used to register (align) a set of tabular documents to each other. Each component of the affine transform is handled separately, which dramatically reduces the total parameter space of the

Luke A. D. Hutchison; William A. Barrett

2004-01-01

39

Preliminary investigation of the elemental variation and diagenesis of a tabular uranium deposit, La Sal Mine, San Juan County, Utah  

USGS Publications Warehouse

Ore in the La Sal mine, San Juan County, Utah, occurs as a typical tabular-type uranium deposit of the-Colorado Plateau. Uranium-vanadium occurs in the Salt Wash Member of the Jurassic Morrison Formation. Chemical and petrographic analyses were used to determine elemental variation and diagenetic aspects across the orebody. Vanadium is concentrated in the dark clay matrix, which constitutes visible ore. Uranium content is greater above the vanadium zone. Calcium, carbonate carbon, and lead show greater than fifty-fold increase across the ore zone, whereas copper and organic carbon show only a several-fold increase. Large molybdenum concentrations are present in and above the tabular layer, and large selenium concentrations occur below the uranium zone within the richest vanadium zone. Iron is enriched in the vanadium horizon. Chromium is depleted from above the ore and strongly enriched below. Elements that vary directly with the vanadium content include magnesium, iron, selenium, zirconium, strontium, titanium, lead, boron, yttrium, and scandium. The diagenetic sequence is as follows: (1) formation of secondary quartz overgrowths as cement; (2) infilling and lining of remaining pores with amber opaline material; (3) formation of vanadium-rich clay matrix, which has replaced overgrowths as well as quartz grains; (4) replacement of overgrowths and detrital grains by calcite; (5) infilling of pores with barite and the introduction of pyrite and marcasite.

Brooks, Robert A.; Campbell, John A.

1976-01-01

40

Genesis of the tabular-type vanadium-uranium deposits of the Henry Basin, Utah  

USGS Publications Warehouse

Tabular-type vanadium-uranium deposits occur in fluvial sandstones of the Salt Wash Member of the Morrison Formation of Late Jurassic age The mineralized intervals and the weakly mineralized lateral extensions are bounded both above and below by zones rich in dolomite cement. Carbon isotope values of dolomite cements indicate that at least two sources of carbon existed. One source appears to be the same as that which formed the bedded carbonates in the evaporites in the Tidwell Member of the Morrison Formation stratigraphically below the mineralized interval. The second carbon source is typical of terrestrially deposited carbonates generally associated with meteoric water-dominated environments. Oxygen isotope values of these dolomites show the same trend of isotopically light values above the mineralized interval and isotopically heavier values in and below that interval; they indicate that two isotopically distinct fluids were involved in the mineralizing process. Some aspects of the origin of gangue and ore phases are explainable on the basis of processes which occurred solely within the saline fluid, but key aspects of ore genesis involved the interaction of the saline and meteoric waters. It is postulated that the solution interface migrated vertically within the stratigraphic section. -from Authors

Northrop, H. R.; Goldhaber, M. B.

1990-01-01

41

Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections Through the Central Appalachian Basin  

USGS Publications Warehouse

Introduction The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and synthetic seismic profiles (Kulander and Ryder, 2005). Commonly, well logs are easier to visualize, manipulate, and interpret when available in a digital format. In recent geologic cross sections E-E' and D-D', constructed through the central Appalachian basin (Ryder, Swezey, and others, in press; Ryder, Crangle, and others, in press), gamma ray well log traces and lithologic logs were used to correlate key stratigraphic intervals (Fig. 1). The stratigraphy and structure of the cross sections are illustrated through the use of graphical software applications (e.g., Adobe Illustrator). The gamma ray traces were digitized in Neuralog (proprietary software) from paper well logs and converted to a Log ASCII Standard (LAS) format. Once converted, the LAS files were transformed to images through an LAS-reader application (e.g., GeoGraphix Prizm) and then overlain in positions adjacent to well locations, used for stratigraphic control, on each cross section. This report summarizes the procedures used to convert paper logs to a digital LAS format using a third-party software application, Neuralog. Included in this report are LAS files for sixteen wells used in geologic cross section E-E' (Table 1) and thirteen wells used in geologic cross section D-D' (Table 2).

Crangle, Robert D., Jr.

2007-01-01

42

Chapter 3: Tabular Data and Graphical Images in Support of the U.S. Geological Survey National Oil and Gas Assessment - Western Gulf Province, Smackover-Austin-Eagle Ford Composite Total Petroleum System (504702)  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on this CD-ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Klett, T. R.; Le, P. A.

2006-01-01

43

Using visual cues for extraction of tabular data from arbitrary HTML documents  

Microsoft Academic Search

We describe a method to extract tabular data from web pages. Rather than just analyzing the DOM tree, we also exploit visual cues in the rendered version of the document to extract data from tables which are not explicitly marked with an HTML table element. To detect tables, we rely on a variant of the well-known X-Y cut algorithm as

Bernhard Krüpl; Marcus Herzog; Wolfgang Gatterbauer

2005-01-01

44

PERFORMANCE DIFFERENCES IN THE USE OF GRAPHIC AND TABULAR DISPLAYS OF MULTIVARIATE DATA  

Microsoft Academic Search

It has been suggested that gmphically displayed multivariate data help decision makers better understand information thy are called on to analyze This study compam judgments made from one recently suggested multivariate display technique with judgments made from traditional tabular displays of financial figures Significant differcnces in task performance are found to be related both to differences in the stimulus sets

David B. MacKay; Angelina Villarreal

1987-01-01

45

Fourier-Mellin registration of line-delineated tabular document images  

Microsoft Academic Search

Image registration (or alignment) is a useful preprocessing tool for assisting in manual data extraction from handwritten forms, as well as for preparing documents for batch OCR of specific page regions. A new technique is presented for fast registration of lined tabular document images in the presence of a global affine transformation, using the Discrete Fourier--Mellin Transform (DFMT). Each component

Luke A. D. Hutchison; William A. Barrett

2006-01-01

46

Automated recognition and extraction of tabular fields for the indexing of census records  

NASA Astrophysics Data System (ADS)

We describe a system for indexing of census records in tabular documents with the goal of recognizing the content of each cell, including both headers and handwritten entries. Each document is automatically rectified, registered and scaled to a known template following which lines and fields are detected and delimited as cells in a tabular form. Whole-word or whole-phrase recognition of noisy machine-printed text is performed using a glyph library, providing greatly increased efficiency and accuracy (approaching 100%), while avoiding the problems inherent with traditional OCR approaches. Constrained handwriting recognition results for a single author reach as high as 98% and 94.5% for the Gender field and Birthplace respectively. Multi-author accuracy (currently 82%) can be improved through an increased training set. Active integration of user feedback in the system will accelerate the indexing of records while providing a tightly coupled learning mechanism for system improvement.

Clawson, Robert; Bauer, Kevin; Chidester, Glen; Pohontsch, Milan; Kennard, Douglas; Ryu, Jongha; Barrett, William

2013-01-01

47

Evaluation of Cathode-Ray Tube protection for the electronic tabular display subsystem (ETABS) engineering model  

NASA Astrophysics Data System (ADS)

This report describes the safety evaluation of the 25-inch (diagonal) rectangular cathode-ray tube (CRT) that is used in the engineering model of the Electronic Tabular Display Subsystem (ETABS). An evaluation of ETABS will be performed at the Federal Aviation Administration (FAA) Technical Center for possible application in FAA Air Route Traffic Control Centers (ARTCC). The safety evaluation included standard industry pressure testing and special implosion testing on 12 CRT samples. Eleven of the twelve CRT samples satisfactorily met the safety requirements for both the pressure and implosion testing. One CRT cracked when subjected to 45 pounds per square inch (psi) of air pressure; however, the CRT did not implode. The 25-inch rectangular CRT will therefore provide a high degree of safety for use in each of the two tabular displays of the ETABS engineering model.

Wilson, A. R.

1981-09-01

48

Significant Effects of Confinement and Catalysis in Formation of Tabular Structures from Peapod Structures  

NASA Astrophysics Data System (ADS)

A large number of experimental and theoretical studies have been reported on buckyballs-containing nanotubes (a.k.a. peapod) structures since the discovery of these materials. It was observed that self- assembled buckyballs with nearly uniform centre-to-centre distances and resemble a nanoscopic peapod. The endofullerenes coalesce into longer capsules by either the electron irradiation or thermal annealing. We applied the recently developed Reactive Force Field (ReaxFF) to study the growth dynamic process starting from C60-buckyball/nanotube peapod structures. We found that the space confinement provided by the single wall nanotube encapsulating the buckyballs, is of critical importance on the coalescence reaction. Furthermore, we also simulated the effects of a Ni-particles on the coalescence process and found a significant reduction on the reaction initiation temperature in the presence of these catalysts. One related quantity is the energy barrier of forming a 4-member ring between adjacent buckyballs. We chose both corannulenes (C20H10) and C60 to compute this energy barrier from quantum mechanic and ReaxFF. The good agreement between these two methods encouraged us to investigate the effect of catalysis on this energy barrier. It turned out that this barrier is lowered by 40% with the aid of catalysis. The piece of research work can help the community to gain better understanding of the complicated growth process in fullerene systems.

Su, Haibin

2005-03-01

49

Modification of the regional stress field by magma intrusion and formation of tabular granitic plutons  

NASA Astrophysics Data System (ADS)

Granitic intrusions typically have large aspect ratios, with an horizontal major axis about 4-8 times the vertical one. Combined structural and geophysical (gravity) data allows distinction between two main types of plutons. Flat-floored plutons (the most represented) are rather thin (3-4 km) and extend in every horizontal direction with a gently dipping floor toward several root zones. These contrast with the thick (>10 km) wedge-shaped plutons, more elongated in one direction with a few root zones. We interpret the shape of flat-floored plutons as the result of a switch in the stress pattern caused by the emplacement of magma. Magma is preferentially emplaced into the plane ( ?1- ?2) perpendicular to the least principal stress component ( ?3). This plane is initially vertical, except for compressional conditions. This dilation causes a local re-organization of the stress field, by increasing the minor and intermediate principal stress components. When they overcome the lithostatic load, a drastic change in the orientation of the opening plane results, switching from vertical to horizontal. This constitutes a change from vertically-oriented, dike-shaped intrusions to sub-horizontal laccoliths. Crustal anisotropies (vertical faults or horizontal zones of different rheology) also contribute to modify the shape of the intrusions. The continual exchange of the intermediate stress components also explains the rounded shape of intrusions in strongly extended regions. Our analysis suggests that the concept of magmas rising to a level of neutral buoyancy is not applicable to many settings. Rather, we suggest that the feedback between displacements resulting from magma intrusion and the local stress pattern controls the geometry of magma emplacement.

Vigneresse, Jean-Louis; Tikoff, Basil; Améglio, Laurent

1999-02-01

50

Time-dependent Behaviour of Deep Level Tabular Excavations in Hard Rock  

Microsoft Academic Search

Summary   Although hard rock is not usually associated with large creep deformation, significant time-dependent behaviour is observed\\u000a in the tabular excavations of the South African gold mines. Time-dependent closure data was collected in stopes of the Ventersdorp\\u000a Contact Reef and Vaal Reef. This data typically consists of a primary closure phase after blasting, followed by a steady-state\\u000a closure phase. This

D. F. Malan

1999-01-01

51

Deriving Tabular Event-Based Specifications from Goal-Oriented Requirements Models  

Microsoft Academic Search

Goal-oriented methods are increasingly popular for elaborating software requirements. They provide systematic support for incrementally building intentional, structural and operational models of the software and its environment together with various techniques for early analysis, e.g., to manage conflicting goals or anticipate abnormal environment behaviors that prevent goals from being achieved. On the other hand, tabular event-based methods are well-established for

Renaud De Landtsheer; Emmanuel Letier; Axel Van Lamsweerde

2003-01-01

52

Multibet 1.0: A Proposal for an ASCII Translation and a Set of Names for Extended IPA Notation, and Unibet 1.0: A Proposal for a Single-Character Translation of IPA for English.  

ERIC Educational Resources Information Center

Two articles propose two systems for American Standard Code for Information Interchange (ASCII) translations of the International Phonetic Alphabet (IPA): Multibet 1.0 and Unibet 1.0. Multibet 1.0 consists of a set of names and a set of ASCII translations for the letters and diacritics of the 1979 version of the "Principles of the International…

MacWhinney, Brian; Marengo, Kathy

1986-01-01

53

Hydrogeology of an ancient arid closed basin: implications for tabular sandstone-hosted uranium deposits  

USGS Publications Warehouse

Hydrogeologic modeling shows that tabular-type uranium deposits in the Grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat. -Author

Sanford, R. F.

1990-01-01

54

A Simple Tool for Integration and Differentiation of Tabular Values in Microsoft Excel  

NASA Astrophysics Data System (ADS)

There are many software alternatives for analyzing experimental data in our physics teaching. I prefer to use Excel® because of its flexibility and widespread use elsewhere in our society. Whatever our students will work with in their future career, they almost certainly will have access to a spreadsheet. For a long time I have missed a tool for integrating and differentiating tabular values in Excel. For every new version I thought it would appear, but it did not. Such a tool could also be useful if you analyze data from other sources than your own experiment, for example, data from the Internet. Therefore, I have written a simple tool that can be integrated seamlessly into Excel as an add-in. It is written in Excels powerful macro language Microsoft Visual Basic for Applications. The tool can be downloaded online1 and there are two versions of it: one for Excel 2003 and one for Excel 2007/2010.

Haugland, Ole Anton

2011-12-01

55

Tabular data and graphical images in support of the U.S. Geological Survey National Oil and Gas Assessment--San Juan Basin Province (5022): Chapter 7 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado  

USGS Publications Warehouse

This chapter describes data used in support of the process being applied by the U.S. Geological Survey (USGS) National Oil and Gas Assessment (NOGA) project. Digital tabular data used in this report and archival data that permit the user to perform further analyses are available elsewhere on this CD–ROM. Computers and software may import the data without transcription from the Portable Document Format files (.pdf files) of the text by the reader. Because of the number and variety of platforms and software available, graphical images are provided as .pdf files and tabular data are provided in a raw form as tab-delimited text files (.tab files).

Klett, T. R.; Le, P. A.

2013-01-01

56

Tabular water properties interface for Hydra-TH : CASL THM.CFD.P6.03 milestone report.  

SciTech Connect

Completion of the CASL L3 milestone THM.CFD.P6.03 provides a tabular material properties capability to the Hydra code. A tabular interpolation package used in Sandia codes was modified to support the needs of multi-phase solvers in Hydra. Use of the interface is described. The package was released to Hydra under a government use license. A dummy physics was created in Hydra to prototype use of the interpolation routines. Finally, a test using the dummy physics verifies the correct behavior of the interpolation for a test water table. 3

Carpenter, John H.; Belcourt, Noel

2013-04-01

57

The table lens: merging graphical and symbolic representations in an interactive focus+context visualization for tabular information  

Microsoft Academic Search

We present a new visualization, called the Table Lens, for visualizing and making sense of large tables. The visual- ization uses a focus+context (fisheye) technique that works effectively on tabular information because it allows display of crucial label information and multiple distal focal areas. In addition, a graphical mapping scheme for depicting table contents has been developed for the most

Ramana Rao; Stuart K. Card

1994-01-01

58

Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer  

NASA Astrophysics Data System (ADS)

Knowledge of iceberg locations is important for safety reasons as well as for understanding many geophysical and biological processes. Originally designed to measure wind speed and direction over the ocean, SeaWinds is a microwave scatterometer that operates at 13.4 GHz (Ku-band) on the QuikSCAT satellite. Radar measurements from SeaWinds are collected and processed on a daily basis using resolution-enhancement techniques to produce daily radar images. Because icebergs scatter microwave energy more than sea ice and sea water, icebergs are detected as high-backscatter targets surrounded by lower-backscatter regions in daily SeaWinds images. As a result, iceberg positions are determined in real-time and a time-series of iceberg positions is maintained in an Antarctic iceberg database by Brigham Young University's Microwave Earth Remote Sensing (MERS) laboratory. Since SeaWinds operates independent of both solar illumination and cloud cover and has a large daily spatial coverage, this paper demonstrates that SeaWinds is an excellent platform to detect and track large tabular icebergs. These icebergs are generally larger than 5 km and are typically characterized as a rough ice plateau above the surrounding sea water or sea ice. The number of icebergs tracked in the MERS Antarctic iceberg database is found to be generally greater than the number of icebergs tracked by the National Ice Center. The movement patterns of all icebergs detected by SeaWinds are also analyzed and 90% of icebergs are found to travel a counter-clockwise path around Antarctica and accumulate in the Weddell and Scotia Seas. Iceberg detection and tracking is demonstrated via multiple case studies that highlight icebergs C-19a and A-22a using the MERS database and through real-time operational support of the 2005, 2008, and 2009 NSF Antarctic cruises. Iceberg positions are validated by using collocated high-resolution satellite imagery and by navigating the NSF ships to physically intercept several large tabular icebergs in the Weddell and Scotia Seas.

Stuart, K. M.; Long, D. G.

2011-06-01

59

Calcium-doped ceria/titanate tabular functional nanocomposite by layer-by-layer coating method  

SciTech Connect

Ca-doped ceria (CDC)/tabular titanate (K{sub 0.8}Li{sub 0.27}Ti{sub 1.73}O{sub 4}, TT) UV-shielding functional nanocomposite with fairly uniform CDC coating layers was prepared through a polyelectrolyte-associated layer-by-layer (LbL) coating method. TT with lepidocrocite-like layered structure was used as the substrate, poly (diallyldimethylammonium chloride) (PDDA) was used as a coupling agent, CDC nanoparticles were used as the main UV-shielding component. CDC/TT nanocomposites with various coating layers of CDC were obtained through a multistep coating process. The phases were studied by X-ray diffraction. The morphology and coating quality were studied by scanning electron microscopy and element mapping of energy dispersive X-ray analysis. The oxidation catalytic activity, UV-shielding ability and using comfort were characterized by Rancimat test, UV-vis spectra and dynamic friction test, respectively. CDC/TT nanocomposites with low oxidation catalytic activity, high UV-shielding ability and good using comfort were finally obtained. - Graphical abstract: Through the control of surface charge of particles calcium-doped ceria/titanate composites with low oxidation catalytic activity, higher UV-shielding ability and excellent comfort was obtained by a facile layer-by-layer coating method.

Liu, Xiang W., E-mail: lxwluck@gmail.co [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Suita (Japan); Devaraju, M.K.; Yin, Shu; Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Suita (Japan)

2010-07-15

60

Calcium-doped ceria/titanate tabular functional nanocomposite by layer-by-layer coating method  

NASA Astrophysics Data System (ADS)

Ca-doped ceria (CDC)/tabular titanate (K 0.8Li 0.27Ti 1.73O 4, TT) UV-shielding functional nanocomposite with fairly uniform CDC coating layers was prepared through a polyelectrolyte-associated layer-by-layer (LbL) coating method. TT with lepidocrocite-like layered structure was used as the substrate, poly (diallyldimethylammonium chloride) (PDDA) was used as a coupling agent, CDC nanoparticles were used as the main UV-shielding component. CDC/TT nanocomposites with various coating layers of CDC were obtained through a multistep coating process. The phases were studied by X-ray diffraction. The morphology and coating quality were studied by scanning electron microscopy and element mapping of energy dispersive X-ray analysis. The oxidation catalytic activity, UV-shielding ability and using comfort were characterized by Rancimat test, UV-vis spectra and dynamic friction test, respectively. CDC/TT nanocomposites with low oxidation catalytic activity, high UV-shielding ability and good using comfort were finally obtained.

W. Liu, Xiang; Devaraju, M. K.; Yin, Shu; Sato, Tsugio

2010-07-01

61

Intra-colonial response to Acroporid ``white syndrome'' lesions in tabular Acropora spp. (Scleractinia)  

NASA Astrophysics Data System (ADS)

‘White syndrome’ is considered to be the most prevalent coral disease on the Great Barrier Reef, characterised by rapid rates of lesion progression and high levels of colony mortality. This study investigated the production and translocation of photoassimilates towards white syndrome lesions (WSLs) and artificially inflicted lesions in healthy and diseased colonies of tabular Acropora spp. to determine the intra-colonial response to white syndrome using 14C labelling. Translocation of 14C labelled photoassimilates was preferentially orientated away from active WSLs, with minimal 14C activity observed in the lesion borders, whilst artificial lesions (ALs) created directly opposite WSL borders showed significantly higher 14C activity, suggesting active translocation of photoassimilates for tissue regeneration. Transport of photoassimilates in healthy coral colonies was preferentially oriented towards ALs with a higher perimeter-area ratio, although translocation towards WSL boundaries was minimal even though the lesion perimeter was often the width of the colony (>200 cm). We suggest that the preferential orientation of photoassimilates away from WSLs may represent a deliberate strategy by the colony to induce a ‘shutdown reaction’ in order to preserve intra-colonial resources within areas of the colony that are more likely to survive and recover.

Roff, G.; Hoegh-Guldberg, O.; Fine, M.

2006-05-01

62

Tabular Water Properties Interface for Hydra-TH: CASL THM.CFD.P6.03 Milestone Report, Computational Shock and Multiphysics, Severe Accident Analysis.  

National Technical Information Service (NTIS)

Completion of the CASL L3 milestone THM.CFD.P6.03 provides a tabular material properties capability to the Hydra code. A tabular interpolation package used in Sandia codes was modified to support the needs of multi-phase solvers in Hydra. Use of the inter...

J. H. Carpenter N. Belcourt

2013-01-01

63

Cumulative radiation effect. Part VI: simple nomographic and tabular methods for the solution of practical problems.  

PubMed

In five previous papers, the concept of the Cumulative Radiation Effect (CRE) has been presented as a scale of accumulative sub-tolerance radiation damage. The biological effect generated in normal connective tissue by fractionated or continuous radiation therapy given in any temporal arrangement is described by the CRE on a unified scale of assessment, so that a unique value of the CRE describes a specific level of radiation effect. The basic methods of evaluating CREs were shown in these papers to facilitate a full understanding of the fundamental aspects of the CRE-system, but these methods can be time-consuming and tediuous for complex situations. In this paper, simple nomographic and tabular methods for the solution of practical problems are presented. An essential feature of solving a CRE problem is firstly to present it in a concise and readily appreciated form, and, to do this, nomenclature is introduced to describe schedules and regimes as compactly as possible. Simple algebraic equations are derived to describe the CRE achieved by multi-schedule regimes. In these equations, the equivalence conditions existing at the junctions between schedules are not explicit and the equations are based on the CREs of the constituent schedules assessed individually without reference to their context in the regime as a whole. This independent evaluations of CREs for each schedule results in a considerable simplification in the calculation of complex problems. The calculations are further simplified by the use of suitable tables and nomograms, so that the mathematics involved is reduced to simple arithmetical operations which require at the most the use of a slide rule but can be done by hand. The order of procedure in the presentation and calculation of CRE problems can be summarised in an evaluation procedure sheet. The resulting simple methods for solving practical problems of any complexity on the CRE-system are demonstrated by a number of examples. PMID:856533

Kirk, J; Gray, W M; Watson, E R

1977-01-01

64

Noise-Tolerant Hyperspectral Signature Classification in Unresolved Object Detection with Adaptive Tabular Nearest Neighbor Encoding  

NASA Astrophysics Data System (ADS)

Accurate spectral signature classification is a crucial step in the nonimaging detection and recognition of spaceborne objects. In classical hyperspectral recognition applications, especially where linear mixing models are employed, signature classification accuracy depends on accurate spectral endmember discrimination. In selected target recognition (ATR) applications, previous non-adaptive techniques for signature classification have yielded class separation and classifier refinement results that tend to be suboptimal. In practice, the number of signatures accurately classified often depends linearly on the number of inputs. This can lead to potentially severe classification errors in the presence of noise or densely interleaved signatures. In this paper, we present an enhancement of an emerging technology for nonimaging spectral signature classification based on a highly accurate, efficient search engine called Tabular Nearest Neighbor Encoding (TNE). Adaptive TNE can optimize its classifier performance to track input nonergodicities and yield measures of confidence or caution for evaluation of classification results. Unlike neural networks, TNE does not have a hidden intermediate data structure (e.g., a neural net weight matrix). Instead, TNE generates and exploits a user-accessible data structure called the agreement map (AM), which can be manipulated by Boolean logic operations to effect accurate classifier refinement through programmable algorithms. The open architecture and programmability of TNE's pattern-space (AM) processing allows a TNE developer to determine the qualitative and quantitative reasons for classification accuracy, as well as characterize in detail the signatures for which TNE does not obtain classification matches, and why such mis-matches occur. In this study AM-based classification has been modified to partially compensate for input statistical changes, in response to performance metrics such as probability of correct classification (Pd) and rate of false detections (Rfa). Adaptive TNE can thus achieve accurate signature classification in the presence of time-varying noise, closely spaced or interleaved signatures, and imaging system optical distortions. We analyze classification accuracy of closely spaced spectral signatures adapted from a NASA database of space material signatures. Additional analysis pertains to computational complexity and noise sensitivity, which are superior to non-adaptive TNE or Bayesian techniques based on classical neural networks.

Schmalz, M.; Key, G.

65

MISR Conversion to ASCII Routines  

... These routines are written in Exelis Visual Information Solutions IDL programming language. They can be run either with a licensed ... with IDL and is available from  Exelis Visual Information Solutions . The IDL VM software can be downloaded from this site or ordered ...

2013-04-01

66

Comparison of Neural Networks and Tabular Nearest Neighbor Encoding for Hyperspectral Signature Classification in Unresolved Object Detection  

NASA Astrophysics Data System (ADS)

Accurate and computationally efficient spectral signature classification is a crucial step in the nonimaging detection and recognition of spaceborne objects. In classical hyperspectral recognition applications using linear mixing models, signature classification accuracy depends on accurate spectral endmember discrimination [1]. If the endmembers cannot be classified correctly, then the signatures cannot be classified correctly, and object recognition from hyperspectral data will be inaccurate. In practice, the number of endmembers accurately classified often depends linearly on the number of inputs. This can lead to potentially severe classification errors in the presence of noise or densely interleaved signatures. In this paper, we present an comparison of emerging technologies for nonimaging spectral signature classfication based on a highly accurate, efficient search engine called Tabular Nearest Neighbor Encoding (TNE) [3,4] and a neural network technology called Morphological Neural Networks (MNNs) [5]. Based on prior results, TNE can optimize its classifier performance to track input nonergodicities, as well as yield measures of confidence or caution for evaluation of classification results. Unlike neural networks, TNE does not have a hidden intermediate data structure (e.g., the neural net weight matrix). Instead, TNE generates and exploits a user-accessible data structure called the agreement map (AM), which can be manipulated by Boolean logic operations to effect accurate classifier refinement algorithms. The open architecture and programmability of TNE's agreement map processing allows a TNE programmer or user to determine classification accuracy, as well as characterize in detail the signatures for which TNE did not obtain classification matches, and why such mis-matches occurred. In this study, we will compare TNE and MNN based endmember classification, using performance metrics such as probability of correct classification (Pd) and rate of false detections (Rfa). As proof of principle, we analyze classification of multiple closely spaced signatures from a NASA database of space material signatures. Additional analysis pertains to computational complexity and noise sensitivity, which are superior to Bayesian techniques based on classical neural networks. [1] Winter, M.E. "Fast autonomous spectral end-member determination in hyperspectral data," in Proceedings of the 13th International Conference On Applied Geologic Remote Sensing, Vancouver, B.C., Canada, pp. 337-44 (1999). [2] N. Keshava, "A survey of spectral unmixing algorithms," Lincoln Laboratory Journal 14:55-78 (2003). [3] Key, G., M.S. SCHMALZ, F.M. Caimi, and G.X. Ritter. "Performance analysis of tabular nearest neighbor encoding algorithm for joint compression and ATR", in Proceedings SPIE 3814:115-126 (1999). [4] Schmalz, M.S. and G. Key. "Algorithms for hyperspectral signature classification in unresolved object detection using tabular nearest neighbor encoding" in Proceedings of the 2007 AMOS Conference, Maui HI (2007). [5] Ritter, G.X., G. Urcid, and M.S. Schmalz. "Autonomous single-pass endmember approximation using lattice auto-associative memories", Neurocomputing (Elsevier), accepted (June 2008).

Schmalz, M.; Ritter, G.; Key, R.

67

supraHex: an R/Bioconductor package for tabular omics data analysis using a supra-hexagonal map.  

PubMed

Biologists are increasingly confronted with the challenge of quickly understanding genome-wide biological data, which usually involve a large number of genomic coordinates (e.g. genes) but a much smaller number of samples. To meet the need for data of this shape, we present an open-source package called 'supraHex' for training, analysing and visualising omics data. This package devises a supra-hexagonal map to self-organise the input data, offers scalable functionalities for post-analysing the map, and more importantly, allows for overlaying additional data for multilayer omics data comparisons. Via applying to DNA replication timing data of mouse embryogenesis, we demonstrate that supraHex is capable of simultaneously carrying out gene clustering and sample correlation, providing intuitive visualisation at each step of the analysis. By overlaying CpG and expression data onto the trained replication-timing map, we also show that supraHex is able to intuitively capture an inherent relationship between late replication, low CpG density promoters and low expression levels. As part of the Bioconductor project, supraHex makes accessible to a wide community in a simple way, what would otherwise be a complex framework for the ultrafast understanding of any tabular omics data, both scientifically and artistically. This package can run on Windows, Mac and Linux, and is freely available together with many tutorials on featuring real examples at http://supfam.org/supraHex. PMID:24309102

Fang, Hai; Gough, Julian

2014-01-01

68

Tabular comparisons of the Flynn Creek impact crater, United States, Steinheim impact crater, Germany and Snowball explosion crater, Canada  

NASA Technical Reports Server (NTRS)

A tabular outline of comparative data is presented for 340 basic dimensional, morphological, and structural parameters and related aspects for three craters of the flat-floored, central uplift type, two of which are natural terrestrial impact craters and one is a large-scale experimental explosion crater. The three craters are part of a general class, in terms of their morphology and structural deformation that is represented on each of the terrestrial planets including the moon. One of the considered craters, the Flynn Creek Crater, was formed by a hypervelocity impact event approximately 360 m.y. ago in what is now north central Tennessee. The impacting body appears to have been a carbonaceous chondrite or a cometary mass. The second crater, the Steinheim Crater, was formed by an impact event approximately 14.7 m.y. ago in what is now southwestern Germany. The Snowball Crater was formed by the detonation of a 500-ton TNT hemisphere on flat-lying, unconsolidated alluvium in Alberta, Canada.

Roddy, D. J.

1977-01-01

69

Graphical and tabular summaries of decay characteristics for once-through PWR, LMFBR, and FFTF fuel cycle materials. [Spent fuel, high-level waste fuel can scrap  

SciTech Connect

Based on the results of ORIGEN2 and a newly developed code called ORMANG, graphical and summary tabular characteristics of spent fuel, high-level waste, and fuel assembly structural material (cladding) waste are presented for a generic pressurized-water reactor (PWR), a liquid-metal fast breeder reactor (LMFBR), and the Fast Flux Test Facility (FFTF). The characteristics include radioactivity, thermal power, and toxicity (water dilution volume). Given are graphs and summary tables containing characteristic totals and the principal nuclide contributors as well as graphs comparing the three reactors for a single material and the three materials for a single reactor.

Croff, A.G.; Liberman, M.S.; Morrison, G.W.

1982-01-01

70

MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies  

Microsoft Academic Search

STD 11, RFC 822 defines a message representation protocol specifying considerable detail about message headers, but which leaves the message content, or message body, as flat ASCII text. This document redefines the format of message bodies to allow multi- part textual and non-textual message bodies to be represented and exchanged without loss of information. This is based on earlier work

N. Borenstein; N. Freed

71

14 CFR 331.23 - In what format must applications be submitted?  

Code of Federal Regulations, 2010 CFR

14 Aeronautics and Space 4 2010-01-01 2010-01-01 false In what format must applications be submitted...addition, you may submit financial and accounting tabular data in Excel spreadsheet format, utilizing a 3.5â³ floppy disk,...

2010-01-01

72

Summary of Findings Tables: Presenting the Main Findings of Cochrane Complementary and Alternative Medicine-related Reviews in a Transparent and Simple Tabular Format  

PubMed Central

The systematic review is widely accepted as the most reliable and objective method for evaluating the effects of healthcare interventions, including complementary and alternative medicine (CAM) therapies. Systematic reviews use explicit, transparent, and well-documented methods to find, evaluate, and synthesize the best available research studies related to a specific research question. Systematic reviews of healthcare treatment typically have focused on randomized controlled trials (RCTs) because RCTs are widely regarded as the study design providing the most reliable estimates of a healthcare treatment's effects. Systematic reviewers aim to evaluate and appraise relevant RCTs using objective and reproducible methods to provide an unbiased assessment of the evidence for a given therapy. Systematic reviews sometimes include a meta-analysis, the quantitative combining (pooling) of results from similar but separate RCTs to obtain an overall effect estimate.

2012-01-01

73

The far field effect of ice shelf calving: the oceanographic effect of the decay of large tabular icebergs at South Georgia  

NASA Astrophysics Data System (ADS)

South Georgia is a small island approximately 190 x 30 km within the Antarctic Circumpolar Current in the South Atlantic. It is surrounded by a continental shelf which extends typically more than 50 km from the coast and has an average depth ~200 m, although there are deeper submarine canyons. It is downstream of the Antarctic Peninsula and satellite observations have frequently shown that very large tabular icebergs which originate in the Bellingshausen and Weddell Seas, for example B10A, A22B and A38, reach the island. Once there they ground on the relatively wide and extensive shelf. Occasionally they can pass the island and continue their drift and decay in the open ocean of the Antarctic Circumpolar Current however, for many, such as A38 (~300 Gt), the region around the island is effectively the graveyard. When this happens potentially very large volumes of meteoric water are deposited onto the shelf of the island and there are consequent large effects on the regional hydrography. The island has been for many decades a long term study site for cross disciplinary work and from 2002-2006 two oceanographic moorings recorded physical parameters including temperature, salinity and water velocity in the region. This time period encompasses the period of A38’s demise. The effects of the melt water addition are clear in the regional situation and here we present melt rate calculations from both tidal forcing and background hydrography on the tabular icebergs, and consequent impacts of the significant freshwater addition at this isolated site.

Brandon, M. A.; Enderlein, P.; Murphy, E.

2010-12-01

74

DataUp 2.0: Improving On a Tool For Helping Researchers Archive, Manage, and Share Their Tabular Data  

NASA Astrophysics Data System (ADS)

There are many barriers to data management and sharing among earth and environmental scientists; among the most significant are a lack of knowledge about best practices for data management, metadata standards, or appropriate data repositories for archiving and sharing data. Last year we developed an open source web application, DataUp, to help researchers overcome these barriers. DataUp helps scientists to (1) determine whether their file is CSV compatible, (2) generate metadata in a standard format, (3) retrieve an identifier to facilitate data citation, and (4) deposit their data into a repository. With funding from the NSF via a supplemental grant to the DataONE project, we are working to improve upon DataUp. Our main goal for DataUp 2.0 is to ensure organizations and repositories are able to adopt and adapt DataUp to meet their unique needs, including connecting to analytical tools, adding new metadata schema, and expanding the list of connected data repositories. DataUp is a collaborative project between the California Digital Library, DataONE, the San Diego Supercomputing Center, and Microsoft Research Connections.

Strasser, C.; Borda, S.; Cruse, P.; Kunze, J.

2013-12-01

75

14 CFR 331.23 - In what format must applications be submitted?  

Code of Federal Regulations, 2010 CFR

...supporting financial documents must be submitted in hard copy. In addition, you may submit financial and accounting tabular data in Excel spreadsheet format, utilizing a 3.5â³ floppy disk, compact disk, or flash memory device, and doing so may expedite...

2009-01-01

76

Sentinel lymph node biopsy for breast cancer using methylene blue dye manifests a short learning curve among experienced surgeons: a prospective tabular cumulative sum (CUSUM) analysis  

PubMed Central

Background The benefits of sentinel lymph node biopsy (SLNB) for breast cancer patients with histologically negative axillary nodes, in whom axillary lymph node dissection (ALND) is thereby avoided, are now established. Low false negative rate, certainly with blue dye technique, mostly reflects the established high inherent accuracy of SLNB and low axillary nodal metastatic load (subject to patient selection). SLN identification rate is influenced by volume, injection site and choice of mapping agent, axillary nodal metastatic load, SLN location and skill at axillary dissection. Being more subject to technical failure, SLN identification seems to be a more reasonable variable for learning curve assessment than false negative rate. Methylene blue is as good an SLN mapping agent as Isosulfan blue and is much cheaper. Addition of radio-colloid mapping to blue dye does not achieve a sufficiently higher identification rate to justify the cost. Methylene blue is therefore the agent of choice for SLN mapping in developing countries. The American Society of Breast Surgeons recommends that, for competence, surgeons should perform 20 SLNB but admits that the learning curve with a standardized technique may be "much shorter". One appropriate remedy for this dilemma is to plot individual learning curves. Methods Using methylene blue dye, experienced breast surgeons performed SLNB in selected patients with breast cancer (primary tumor < 5 cm and clinically negative ipsilateral axilla). Intraoperative assessment and completion ALND were performed for standardization on the first 13 of 24 cases. SLN identification was plotted for each surgeon on a tabular cumulative sum (CUSUM) chart with sequential probability ratio test (SPRT) limits based on a target identification rate of 85%. Results The CUSUM plot crossed the SPRT limit line after 8 consecutive, positively identified SLN, signaling achievement of an acceptable level of competence. Conclusion Tabular CUSUM charting, based on a justified choice of parameters, indicates that the learning curve for SLNB using methylene blue dye is completed after 8 consecutive, positively identified SLN. CUSUM charting may be used to plot individual learning curves for trainee surgeons by applying a proxy parameter for failure in the presence of a mentor (such as failed SLN identification within 15 minutes).

East, Jeffrey M; Valentine, Christopher SP; Kanchev, Emil; Blake, Garfield O

2009-01-01

77

Directory interchange format manual, version 3.0  

NASA Technical Reports Server (NTRS)

The Directory Interchange Format (DIF) is a data structure used to exchange directory level information about data sets among information systems. The format consists of a number of fields that describe the attributes of a directory entry and text blocks that contain a descriptive summary of and references for the directory entry. All fields and the summary are preceded by labels identifying their contents. All values are ASCII character strings. The structure is intended to be flexible, allowing for future changes in the contents of directory entries.

1990-01-01

78

MIME (Multipurpose Internet Mail Extensions): Mechanisms for Specifying and Describing the Format of Internet Message Bodies  

Microsoft Academic Search

RFC 822 defines a message representation protocol which specifies considerable detailabout message headers, but which leaves the message content, or message body, as flatASCII text. This document redefines the format of message bodies to allow multi-parttextual and non-textual message bodies to be represented and exchanged without loss ofinformation. This is based on earlier work documented in RFC 934 and RFC

N. Borenstein; N. Freed

1992-01-01

79

Origin and significance of organic matter in uranium deposits of Morrison Formation, San Juan Basin, New Mexico  

Microsoft Academic Search

Primary uranium orebodies in the Morrison Formation of the San Juan Basin, New Mexico, consist of submicroscopic coffinite in a matrix of dark-colored structureless carbonaceous matter that impregnates and partially replaces the Morrison sandstones. Recognizable carbonized plant fragments are also abundant both in and near ore. The orebodies are elongated, lenticular or tabular masses; they are oriented parallel to paleochannel

Squyres

1980-01-01

80

The Algoma-type iron-formations of the Nigerian metavolcano-sedimentary schist belts  

Microsoft Academic Search

Field relationships as well as petrographical and geochemical considerations form the basis of a model for the origin of the protoliths of the iron-formations and the associated phyllitic host rock of the Palaeoproterozoic schist belts of northern Nigeria. The iron-formations which consist of both the magnetite-subfacies and silicatefacies occur as relatively small, sporadic tabular bodies throughout the belts. They are

A. Mücke; A. Annor; U. Neumann

1996-01-01

81

Ichnology of Lower Jurassic beach deposits in the Shemshak Formation at Shahmirzad, southeastern Alborz Mountains, Iran  

Microsoft Academic Search

A 19 m thick package of well-sorted lowermost Jurassic (Hettangian-Lower Sinemurian?) sandstones within the Shemshak Formation\\u000a of the southeastern Alborz Mountains displays features characteristic of foreshore to upper shoreface environments such as\\u000a tabular bedding, low-angle lamination, trough cross-stratification, parting lineation, and oscillation ripples. In contrast\\u000a to most other beach successions recorded in the literature the sandstones contain a trace fossil assemblage

Franz T. Fürsich; Markus Wilmsen; Kazem Seyed-Emami

2006-01-01

82

Documentation for ASCII Text Data Files - SEER Datasets  

Cancer.gov

SEER is an authoratitive source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.

83

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: Basin Characteristics, 2002 Geospatial_Data_Presentation_Form: tabular digital data  

USGS Publications Warehouse

This tabular data set represents basin characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River Basins (MRBs, Crawford and others, 2006). These characteristics are reach catchment shape index, stream density, sinuosity, mean elevation, mean slope and number of road-stream crossings. The source data sets are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011) and the U.S. Census Bureau's TIGER/Line Files (U.S. Census Bureau,2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-Atlantic (MRB1), South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great basin (MRB6), the Pacific Northwest (MRB7) river basins, and California (MRB8).

Wieczorek, Michael E.; LaMotte, Andrew E.

2010-01-01

84

Tabular Equation of State for Gold  

NASA Astrophysics Data System (ADS)

A new, Sesame-type equation of state (EOS) is described for gold, suitable for use in hydrodynamic calculations. The EOS is tabulated on a rectangular temperature-and- density grid, spanning densities from 0 -- 29 g/cc, temperatures from 0 -- 85,000 K, and extending up to pressures of 1000 GPa. It is constructed using the standard decomposition of the pressure into a static-lattice cold curve, a thermal nuclear contribution, and a thermal electronic contribution. The cold curve is derived from a combination of empirical data and density functional theory, the thermal nuclear contribution from the Johnson model, and the thermal electronic contribution using Thomas-Fermi-Dirac theory. Pressures, internal energies, and Helmholtz free energies are tabulated as functions of temperature and density. Predictions for the room-temperature isotherm, principal Hugoniot, thermal expansion, heat capacity, and vapor pressure are compared with experimental data and with the EOS currently available in the Sesame library (Sesame 2700).

Boettger, Jonathan; Honnell, Kevin; Peterson, Jeffrey; Greeff, Carl; Crockett, Scott

2011-06-01

85

Tabular equation of state for gold  

NASA Astrophysics Data System (ADS)

A new, SESAME-type equation of state (EOS) , suitable for use in hydrodynamic calculations, is described for gold. Pressures, internal energies, and Helmholtz free energies are tabulated on a rectangular temperature-and-density grid, spanning densities from 0 - 36 g/cc, temperatures from 0 - 800 eV, and extending up to pressures of 800 GPa. The EOS is constructed using the standard decomposition of the pressure into a static-lattice cold curve, a thermal nuclear contribution, and a thermal electronic contribution. The cold curve is derived from existing diamond-anvil-cell measurements, the thermal nuclear contribution from the Johnson model, and the thermal electronic contribution using Thomas-Fermi-Dirac theory. Predictions of the new EOS (SESAME 2705) for the cold curve, roomtemperature isotherm, principal Hugoniot, thermal expansion, heat capacity, melt line, and vapor pressure compare favorably with experimental data and are superior to the EOS currently available in the SESAME library (SESAME 2700).

Boettger, Jonathan; Honnell, Kevin G.; Peterson, Jeffrey H.; Greeff, Carl; Crockett, Scott

2012-03-01

86

Directory interchange format manual, version 4.0  

NASA Technical Reports Server (NTRS)

The Directory Interchange Format (DIF) is a data structure used to exchange directory-level information about data sets among information systems. In general the format consists of a number of fields that describe the attributes of a directory entry and text blocks that contain a descriptive summary of and references for the directory entry. All fields and the summary are preceded by labels identifying their contents. All values are ASCII character strings. The structure is intended to be flexible, allowing for future changes in the contents of directory entries. The manual is structured as follows: section 1 is a general description of what constitutes a directory entry; section 2 describes the content of the individual fields within the data structure, together with some examples. Also included in the six appendices is a description of the syntax used within the examples; samples of the directory interchange format applied to different data sets; the allowable discipline keywords; a current list of valid location keywords; a list of allowable parameter keywords; a list of acronyns and a glossary of terms used; and a description of the Standard Formatted Data Unit header, which may be added to the front of a DIF file to identify the file as a registered standard format.

1991-01-01

87

The digital geologic map of Wyoming in ARC/INFO format  

USGS Publications Warehouse

This geologic map was prepared as part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Wyoming (Love and Christiansen, 1985). Consequently, the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the State base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1985 geologic map. Descriptors: The Digital Geologic Map of Wyoming in ARC/INFO Format Open-File Report 94-0425

Green, G. N.; Drouillard, P. H.

1994-01-01

88

BOREAS TF-9 SSA-OBS Branch Level Flux Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-9 team collected data that describe carbon dioxide and water vapor fluxes from foliage at the BOREAS SSA-OBS site from 07-April through 23-November-1996. The data are available in tabular ASCII files.

Rayment, Mark B.; Jarvis, Paul G.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

89

BOREAS RSS-8 BIOME-BGC Model Simulations at Tower Flux Sites in 1994  

NASA Technical Reports Server (NTRS)

BIOME-BGC is a general ecosystem process model designed to simulate biogeochemical and hydrologic processes across multiple scales (Running and Hunt, 1993). In this investigation, BIOME-BGC was used to estimate daily water and carbon budgets for the BOREAS tower flux sites for 1994. Carbon variables estimated by the model include gross primary production (i.e., net photosynthesis), maintenance and heterotrophic respiration, net primary production, and net ecosystem carbon exchange. Hydrologic variables estimated by the model include snowcover, evaporation, transpiration, evapotranspiration, soil moisture, and outflow. The information provided by the investigation includes input initialization and model output files for various sites in tabular ASCII format.

Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

2000-01-01

90

Rectangular subsonic jet flow field measurements  

NASA Technical Reports Server (NTRS)

Flow field measurements are presented of 3 subsonic rectangular cold air jets. The 3 cases presented had aspect ratios of 1 x 2, 1 x 4 at a Mach number of 0.09 and an aspect ratio of 1 x 2 at a Mach number of 0.9. All measurements were made using a 3-D laser Doppler anemoneter system. The presented data includes the mean velocity vector, all Reynolds stress tensor components, turbulent kinetic energy and velocity correlation coefficients. The data is presented in tabular and graphical form. No analysis of the measured data or comparison to other published data is made. All tabular data are available in ASCII format on MS-DOS compatible disks.

Morrison, Gerald L.; Swan, David H.

1989-01-01

91

Facies architecture and depositional environments of the Upper Cretaceous Kaiparowits Formation, southern Utah  

NASA Astrophysics Data System (ADS)

The Kaiparowits Formation is an unusually thick package of Upper Cretaceous (late Campanian) strata exposed in Grand Staircase-Escalante National Monument of southern Utah, USA. The formation was deposited within the rapidly subsiding Cordilleran foreland basin as part of a thick clastic wedge derived from sources in the Sevier orogenic belt, thrust sheets in southeastern Nevada and southern California, and the Mogollon slope in southwestern Arizona. Channel systems in the Kaiparowits Formation shifted from northeastward to southeastward flow over time, and for a short period of time, sea level rise in the Western Interior Seaway resulted in tidally influenced rivers and/or estuarine systems. Thick floodbasin pond deposits, large suspended-load channels, and poorly developed, hydromorphic paleosols dominate the sedimentary record, and all are suggestive of a relatively wet, subhumid alluvial system. This is supported by extremely rapid sediment accumulation rates (41 cm/ka), and high diversity and abundance of aquatic vertebrate and invertebrate fossils. Facies and architectural analysis was performed on the Kaiparowits Formation, resulting in the identification of nine distinct facies associations: 1) intraformational conglomerate, 2) mollusc-shell conglomerate, 3) major tabular sandstone, 4) major lenticular sandstone, 5) minor tabular and lenticular sandstone, 6) finely laminated, calcareous siltstone, 7) inclined heterolithic sandstone and mudstone, 8) sandy mudstone, and 9) carbonaceous mudstone. These facies associations are interpreted as: 1) channel lags, 2) rare channel-hosted storm beds, 3) meandering channels, 4) anastomosing channels, 5) crevasse splays and crevasse channels, 6) lakes, 7) tidally influenced fluvial and/or estuarine channels, 8) mud-dominated floodplains, and 9) swamps and oxbow lakes. Based on this analysis, the formation is subdivided into three informal units, representative of gross changes in alluvial architecture, including facies stacking patterns, sandstone/mudstone ratios, and interpreted channel morphology. Alluvial architecture and stacking patterns in the Kaiparowits Formation were controlled by a combination of allogenic controls, most significantly tectonics followed by climate and eustasy.

Roberts, Eric M.

2007-04-01

92

Drop Formation  

NSDL National Science Digital Library

This site from the University of BristolâÂÂs Mathematics department contains an explanation of drop formation and its applications. A description of studies of drop separation and its applications in medicine and technology are provided. The site also contains photographs, including a series of images showing the formation of a satellite drop.

2010-03-25

93

Soil Formation  

NSDL National Science Digital Library

Humans use soil for their daily needs but do not sufficiently take account of its slow formation and fast loss. Discover the amazing geology of soil formation and the basic rock and soil types.Although soil seems the end product from weathering rocks, it is merely a stage in the gigantic cycle of mineral recycling by the movement of tectonic plates.

2008-07-24

94

Regolith Formation  

NSDL National Science Digital Library

In this three-part activity, learners use food to determine the effects of wind, sandblasting and water on regolith (dust) formation and deposition on Earth. Then, learners simulate regolith formation on the Moon by meteorite bombardment, an activity best completed outdoors.

Nasa

1997-01-01

95

CURSA: Catalog and Table Manipulation Applications  

NASA Astrophysics Data System (ADS)

The CURSA package manipulates astronomical catalogs and similar tabular datasets. It provides facilities for browsing or examining catalogs; selecting subsets from a catalog; sorting and copying catalogs; pairing two catalogs; converting catalog coordinates between some celestial coordinate systems; and plotting finding charts and photometric calibration. It can also extract subsets from a catalog in a format suitable for plotting using other Starlink packages such as PONGO. CURSA can access catalogs held in the popular FITS table format, the Tab-Separated Table (TST) format or the Small Text List (STL) format. Catalogs in the STL and TST formats are simple ASCII text files. CURSA also includes some facilities for accessing remote on-line catalogs via the Internet. It is part of the Starlink software collection (ascl:1110.012).

Davenhall, A. C.

2014-05-01

96

Star Formation  

NASA Astrophysics Data System (ADS)

Stars are one of the most important constituents of the Universe, and understanding their formation is crucial to many areas of astrophysics. Stars form from dense molecular gas, and they tend not to form in isolation. Stars often form in binary and multiple systems, and these systems tend to form in clusters with 102-105 members. Stars also form with a wide range of masses, from substellar brown dwarfs with masses < 0. 1 M ? to massive stars > 100 M ?, and wherever stars form the distribution of their masses seems always to be the same. This chapter will review our current understanding of star formation from cold gas to young star clusters.

Goodwin, Simon

97

Planet Formation  

NASA Astrophysics Data System (ADS)

1. Historical notes on planet formation Bodenheimer; 2. The formation and evolution of planetary systems Bouwman et al.; 3. Destruction of protoplanetary disks by photoevaporation Richling, Hollenbach and Yorke; 4. Turbulence in protoplanetary accretion disks Klahr, Rozyczka, Dziourkevitch, Wunsch and Johansen; 5. The origin of solids in the early solar system Trieloff and Palme; 6. Experiments on planetesimal formation Wurm and Blum; 7. Dust coagulation in protoplanetary disks Henning, Dullemond, Wolf and Dominik; 8. The accretion of giant planet cores Thommes and Duncan; 9. Planetary transits: direct vision of extrasolar planets Lecavelier des Etangs and Vidal-Madjar; 10. The core accretion - gas capture model Hubickyj; 11. Properties of exoplanets Marcy, Fischer, Butler and Vogt; 12. Giant planet formation: theories meet observations Boss; 13. From hot Jupiters to hot Neptures … and below Lovis, Mayor and Udry; 14. Disk-planet interaction and migration Masset and Kley; 15. The Brown Dwarf - planet relation Bate; 16. From astronomy to astrobiology Brandner; 17. Overview and prospective Lin.

Klahr, Hubert; Brandner, Wolfgang

2011-02-01

98

Formation Control  

Microsoft Academic Search

This paper deals with vision-based localization for leader- follower formation control. Each unicycle robot is equipped with a panoramic camera that only provides the view angle to the other robots. The localization problem is studied using a new observability condition valid for general nonlinear systems and based on the extended output Jacobian. This allows us to identify those robot motions

Gian Luca Mariottini; Fabio Morbidi; Domenico Prattichizzo; Nicholas Vander Valk; Nathan Michael; George Pappas; Kostas Daniilidis

99

Pattern formation in magma dynamics: The oscillatory instability  

NASA Astrophysics Data System (ADS)

The extraction of partial melt from planetary interiors is the key mechanism that links surface observations to the structure and processes in the interior. Outcrops of mantle materials (ophiolites) show a striking tabular or channel-like pattern of almost pure dunite imbedded in residual harzburgite and lherzolite matrices. Viscous deformation of the solid matrix and the reactive porous flow of the buoyant melt may give rise to instabilities that lead to the formation of channel-like patterns. We present an extended physicochemical hydrodynamic model that explicitly computes the chemical depletion of the solid matrix as well as the chemical and mechanic interactions between the deforming matrix and the reacting melt. We present linear stability results and high-resolution high-accuracy numerical simulations. Two distinct types of instability are observed: a channeling instability similar to that reported by Aharonov et al. (1995) and a new oscillatory or wave-like instability. The oscillatory instability leads to dynamic checkerboard patterns in the melt fraction (porosity) and compaction rate that migrate upwards in the upwelling column. The numerical simulations show progressive chemical depletion along the vertical nodal lines of the checkerboard pattern and may offer an alternative explanation for the formation of the dunite channels. A parameter study suggests that the oscillatory instability may play an important role for melt migration beneath the mid-ocean ridge. references: Aharonov, E., J. Whitehead, P. Kelemen, and M. Spiegelman (1995), Channeling instability of upwelling melt in the mantle, J. Geophys. Res., 100(B10), 20433-20450.

Hesse, M. A.; Schiemenz, A.; Liang, Y.; Parmentier, E.

2009-12-01

100

Electronic factors for K-shell-electron conversion probability and electron-positron pair formation probability in electric monopole transitions  

NASA Astrophysics Data System (ADS)

This paper presents, in tabular form, the electronic factors Omega /sub K, pi/(Z,k) of the electric monopole transition probability associated with the internal conversion of an electron from the atomic K shell (IC;K) and with the internal pair formation (IPF;pi). The Omega /sub pi/ values are calculated by taking the nuclear Coulomb effects into account. The corrections to Omega /sub K/ due to finite nuclear size and bound-state atomic screening are not included in the present calculations. The calculated ratio of the K-shell-electron conversion probability to the electron-positron pair formation probability is found to be in good agreement with the available experimental data for Z is equal to or less than 40.

Passoja, A.; Salonen, T.

1986-04-01

101

Galaxy formation  

PubMed Central

It is argued that within the standard Big Bang cosmological model the bulk of the mass of the luminous parts of the large galaxies likely had been assembled by redshift z ? 10. Galaxy assembly this early would be difficult to fit in the widely discussed adiabatic cold dark matter model for structure formation, but it could agree with an isocurvature version in which the cold dark matter is the remnant of a massive scalar field frozen (or squeezed) from quantum fluctuations during inflation. The squeezed field fluctuations would be Gaussian with zero mean, and the distribution of the field mass therefore would be the square of a random Gaussian process. This offers a possibly interesting new direction for the numerical exploration of models for cosmic structure formation.

Peebles, P. J. E.

1998-01-01

102

ANTIBODY FORMATION  

PubMed Central

Injection of a sufficient dose of bacteriophage ?X 174 into guinea pigs results in the formation of rapidly sedimenting antibody molecules (19S), and later, slowly sedimenting molecules (7S). Above a threshold dose of antigen, the relative rate of 19S formation is maximal and dose-independent; below this dose, slower relative rates are obtained. The time for doubling the serum 19S level is as short as 6 to 8 hours, suggesting that the absolute rate of antibody formation per cell is increasing in addition to proliferation of antibody-producing cells. Synthesis of 19S after injection of 1010 ?X virtually ceases at 10 days after which 19S antibody activity disappears from the circulation with a half-life of approximately 24 hours. A second injection of ?X on day 5 or 9 prolongs 19S synthesis, indicating that antigen not only can regulate the relative rate, but also is essential for continued synthesis of 19S. 19S synthesis is also prolonged in guinea pigs by injection of ?X with endotoxin or by 400 r whole body x-irradiation 24 hours after injection of phage into rabbits. The primary 7S response is not detected until approximately 1 week after immunization and relative rates are antigen-dependent. Primary 7S synthesis can continue for many months and leads to preparation for a secondary antibody response (immunological memory) during which only 7S is detected. In contrast, in animals that form precipitating 19S without detectable 7S, a second injection of phage 1 month later results in a second 19S response which closely resembles the first. These findings have led to the suggestion that formation of 19S does not lead to persisting immunological memory.

Uhr, Jonathan W.; Finkelstein, Martin S.

1963-01-01

103

Fossil formation  

NSDL National Science Digital Library

The National Science Education Standards Life Science Content Standard mentions that fossils indicate extinct species and contribute to an understanding of evolution and diversity. The Earth and Space Sciences Content Standard tells us they provide clues about past environments. But what is a fossil? How does it form? The processes can be complex. An understanding of fossil formation will enable accurate student conceptions of related science concepts including methods of science in geology, paleontology, and evolution.

University, Staff A.

2008-03-07

104

16 CFR 4.2 - Requirements as to form, and filing of documents other than correspondence.  

Code of Federal Regulations, 2010 CFR

...in ASCII format, WordPerfect, or Microsoft Word). Except as otherwise provided...in ASCII format, WordPerfect, or Microsoft Word). (2) The first page of the...in ASCII format, WordPerfect, or Microsoft Word) by e-mail, as the...

2009-01-01

105

Sedimentology of tidally deposited Miocene Bear Lake formation, Alaskan Peninsula  

SciTech Connect

The Miocene Bear Lake Formation - chiefly sandstone, shale, and conglomerate - crops out on the Alaskan Peninsula between Port Heiden and Pavlof Bay. As thick as 1600 m in outcrop and 2368 m in subsurface, the Bear Lake Formation appears to have been deposited mostly by tidal processes in a semi-enclosed back-arc basin that was bordered to the southeast by volcanic uplands of the Aleutian arc. To the northeast, the basin originally extended beneath Britstol Bay as part of the North Aleutian basin. The Bear Lake Formation, which rests unconformably on Oligocene volcanogenic sedimentary rocks and is unconformably overlain by Pliocene volcanic rocks, contains few, if any, interbedded volcanic rocks. Sandstone of the Bear Lake Formation contains more quartz, locally as much as 65%, than most Tertiary strata of the Alaska Peninsula. Rounded clasts of granitic rocks as large as 25 cm were probably derived from large batholithic complexes to the southeast. Sandstone beds are characterized by large-scale trough and tangential tabular cross-strata, herringbone cross-strata, shale drapes on cross-strata, reactivation surfaces, channeling, superposition of small-scale cross-strata or current ripple markings on large-scale cross-strata with reversal flow directions, scattered megafossils, local coquinas, and local burrows that include Ophiomorpha. Shaly sequences are characterized by flaser bedding, current and oscillation ripple markings, starved ripple markings, abundant small-scale bioturbation, load coasts, abundant mica and plant fragments, and synsedimentary slumps. Coarse-grained fluvial deposits at the base and fine-grained marine shelf deposits at the top of many sections suggest deposition during a major transgression, possibly as a result of subsidence of the Aleutian arc during an interval of relative volcanic quiescene.

Nilsen, T.H.

1985-04-01

106

Formation of the Upper Cretaceous cherts in northeastern Sinai, Egypt  

NASA Astrophysics Data System (ADS)

The Upper Cretaceous cherts in northeast Sinai, Egypt are found as nodules, tabular sheets and continuous beds within the carbonate dominated successions. They occur in the Halal, Wata and Matulla Formations and become a very conspicuous constituent in the Sudr Chalk. The chert framework is typical of all interstratal structures and is of two types: spotted and brecciated forms. The chert is classified into a fossiliferous and nonfossiliferous variety. The first is likely either to form packstone-grainstone fabrics or to form wackestone fabrics. The packstone-grainstone fabric is interpreted as replacing platform carbonate deposits at relatively lower energy but in an oxygenated environment while the wackestone fabric chert replaces low energy deep water carbonates. This Upper Cretaceous silica cycle was dominated by inorganic reactions involving dissolved silica, and there is much evidence of secondary diagenetic silicification. This process would have started in early diagenesis as opal-A, opal-C and opal-CT precipitated from interstitial waters. Quartz represents the end product of recrystallisation. This transformation from metastable to stable silica phases is explained as a solid-solid diagenetic reaction as emphasised by ?18O. The nodular cherts have formed in coastal mixing zones with opal-CT and quartz supersaturation and calcite undersaturation. The source of silica of the deep water cherts cannot be explained by this mixing zone model and needs further study. On the other hand, there is no evidence of deposition of layered amorphous silica in either shallow or deep environments.

Genedi, Adel

1998-02-01

107

PROLOG Implementation of a Tabular Bottom-Up Recognizer.  

National Technical Information Service (NTIS)

A 'double-dotted' algorithm of parsing and recognizing for context free grammars not necessarily in Chomsky normal form has been developed recently by one of the authors (see PB90-211996). The algorithm is essentially parallel. The present note is devoted...

P. Kruszynski J. P. M. de Vreught

1991-01-01

108

Developments in south Texas in 1979. [Tabular data and map  

Microsoft Academic Search

The South Texas report includes 58 counties in Texas Railroad Districts 1, 2, and 4 and parts of the Texas offshore. District 1 exploration activity increased 8.9% from 1978. However, the success rate was down from 30.7% in 1978 to 23.1% for this year. Drilling for Upper Cretaceous pays was the focus of activity in 1979. Average well depth was

Fergeson

1980-01-01

109

MHD simulations of MTF implosions with tabular EOS and conductivities  

Microsoft Academic Search

Magnetized target fusion (MTF) is a pulsed approach that compresses magnetized fuel to achieving burning hydrogen plasma conditions. The compression in one MTF-scenario comes from uses a conducting liner that is imploded due to the action of high electrical currents that flow on the outer surface of the liner. This implosion compresses and heats a dense, warm magnetized deuterium or

R. J. Faehl; W. L. Atchison; I. R. Lindemuth

2003-01-01

110

Consistent thermodynamic derivative estimates for tabular equations of state  

Microsoft Academic Search

Numerical simulations of compressible fluid flows require an equation of\\u000astate (EOS) to relate the thermodynamic variables of density, internal energy,\\u000atemperature, and pressure. A valid EOS must satisfy the thermodynamic\\u000aconditions of consistency (derivation from a free energy) and stability\\u000a(positive sound speed squared). When phase transitions are significant, the EOS\\u000ais complicated and can only be specified in

Gary A. Dilts

2006-01-01

111

Population Change and California's Future. Detailed Tabular Projections.  

ERIC Educational Resources Information Center

This document consists entirely of 132 tables which present statistics on the projected population size of 12 racial and ethnic groups in California: non-Hispanic Whites; Blacks; Hispanics; Chinese; Filipinos; Asian Indians; Japanese; Koreans; Southeast Asians; Vietnamese; Other Asians; and other groups. An accompanying report deals with these…

Bouvier, Leon F.; Martin, Philip

112

Spatial data in geographic information system format on agricultural chemical use, land use, cropping practices in the United States  

USGS Publications Warehouse

The spatial data in geographic information system format described in this report consist of estimates for all counties in the conterminous United States of the annual use of 96 herbicides in 1989; annual sales of nitrogen fertilizer, in tons, for 1985-91; and agricultural expenses, land use, chemical use, livestock holdings, and cropping practices in 1987. The source information, originally in tabular form, is summarized as digital polygon attribute data in the 18 geographic information system spatial data layers (coverages) provided. The information in these coverages can be used in estimating regional agricultural-chemical use or agricultural practices and in producing visual displays and mapping relative rates of agricultural-chemical use or agricultural practices across broad regions of the United States.

Battaglin, W. A.; Goolsby, D. A.

1995-01-01

113

BOREAS RSS-3 Reflectance Measured from a Helicopter-Mounted Barnes MMR  

NASA Technical Reports Server (NTRS)

The BOREAS RSS-3 team acquired helicopter-based radiometric measurements of forested sites with a Barnes MMR. The data were collected in 1994 during the three BOREAS IFCs at numerous tower and auxiliary sites in both the NSA and SSA. The 15-degree FOV of the MMR yielded approximately 79-m ground resolution from an altitude of 300 m. The MMR has seven spectral bands that are similar to the Landsat TM bands, ranging from the blue region to the thermal. The data are stored in tabular ASCII files. The data are stored in tabular ASCII files.

Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Walthall, Charles L.; Loechel, Sara; deColstoun, Eric Brown

2000-01-01

114

ASCII based transcription systems for languages with the Arabic script: the case of Persian  

Microsoft Academic Search

We discuss transcription systems needed for automated spoken language processing applications in languages such as Persian that use the Arabic script for writing. The work is described in the context of a speech-to-speech translation system development for English and Persian. This system can easily be modified for Arabic, Dari, Urdu and any other language that uses the Arabic script. The

Shadi Ganjavi; Panayiotis G. Georgiou; Shrikanth Narayanan

2003-01-01

115

MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text  

Microsoft Academic Search

Status of this Memo This RFC specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the \\

K. Moore

116

Converting 80-character ASCII IGES sequential files into more conveniently accessible direct-access files  

Microsoft Academic Search

One of the main drawbacks of the Initial Graphics Exchange Specification (IGES) is the difficulty of accessing and retrieving the required information stored in the IGES files. This is because IGES files created by CAD systems are sequential. This paper describes a module, called “readiges”, which is a general-purpose software package for re-storing IGES files in more conveniently accessible direct-access

M. Kalta; B. J. Davies

1993-01-01

117

Realistic MHD Simulations of Formation of Sunspot-like Structures and Comparison with Observations  

NASA Astrophysics Data System (ADS)

The process of formation of magnetic structures such as sunspot and pores in the turbulent convection zone is still enigma. However, the recent progress in numerical radiative MHD simulations provides clues about the possible mechanism of magnetic field accumulation in spontaneously formed stable structures. Implementation of sub-grid turbulent models in our "SolarBox" code, gives us the possibility to model more accurately turbulent properties, and reproduce the dynamics of the magnetized plasma. The code takes into account non-ideal (tabular) EOS, effects of ionization, chemical composition, radiation, turbulence and magnetic field. Our simulation results show an important role of vortices, which create local cavity of pressure and are associated with strong converging flows under the surface, during the initial stage of the spontaneous structure formation. The resulting structure represents a compact self-organized concentration of strong magnetic field, reaching ~6 kG in the interior, and ~1.5 kG on the surface. It has a cluster-like internal structurization, and is maintained by strong downdrafts extending into the deep layers. We discuss the role of turbulent MHD dynamics in this mechanism, and compare the simulation results with observations of the sunspot formation process during a magnetic flux emergence, from the Solar Dynamics Observatory and Hinode.

Kitiashvili, I. N.; Kosovichev, A. G.; Mansour, N. N.; Wray, A. A.

2010-12-01

118

Initial development and performance evaluation of a process for formation of dense carbon by pyrolysis of methane  

NASA Technical Reports Server (NTRS)

The three steps in pyrolytic carbon formation are: (1) gaseous hydrocarbon polymerization and aromatic formation; (2) gas-phase condensation and surface adsorption/impingement of polyaromatic hydrocarbon; and (3) final dehydration to carbon. The structure of the carbon in the various stages of formation is examined. The apparatuses and experimental procedures for the pyrolysis of methane in a 60 cm long quartz reactor tube at temperatures ranging from 1400-1600 K are described. The percentage of carbon converted and its density are calculated and tabularly presented. The results reveal that dense carbon formation is maximized and soot eliminated by this procedure. It is observed that conversion efficiency depends on the composition of the inlet gas and conversion increases with increasing temperature. Based on the experimental data a three-man carbon reactor subsystem (CRS) is developed; the functions of the Sabatier Methanation Reactor, two carbon formation reactors and fluid handling components of the CRS are analyzed. The CRS forms 16 kg of carbon at a rate of 0.8 kg/day for 20 days in a two percent volume density quartz wool packing at temperature of 1500-1600 K.

Noyes, G. P.; Cusick, R. J.

1985-01-01

119

Treatment of sandstone formations  

Microsoft Academic Search

A method of treating a subterranean sandstone formation with an aqueous acid solution containing hydrofluoric acid is described. The reaction rate of the acid with the formation is retarded and substantial penetration of the formation with active acid results. When the hydrofluoric acid solution contacts the sandstone formation, siliceous minerals and clay in the formation are dissolved, thereby increasing the

J. A. Knox; R. M. Lasater

1974-01-01

120

RAMPRF: A program for synchronous acceleration  

SciTech Connect

We describe a family of standard FORTRAN programs that calculate bucket-related quantities as a function of time during acceleration, assuming it is adiabatic. The members of the family are distinguished by the type of input: One family member takes energy and total peak voltage as a function of time; another takes momentum and bucket area as a function of time, etc. The input is in free-format tabular form. The output is in standard ASCII form, in multi-column tables and x-y listings appropriate for plotting. Bunch-related quantities, such as energy spread and space-charge tune spread, are also calculated assuming that the bunches have a specified longitudinal emittance, and are small and matched to the bucket. Sample excitation curves for the SSC's low energy booster are presented. 4 refs., 2 figs.

Furman, M.A.

1991-05-01

121

BOREAS RSS-17 Stem, Soil, and Air Temperature Data  

NASA Technical Reports Server (NTRS)

The BOREAS RSS-17 team collected several data sets in support of its research in monitoring and analyzing environmental and phenological states using radar data. This data set consists of tree bole and soil temperature measurements from various BOREAS flux tower sites. Temperatures were measured with thermistors implanted in the hydroconductive tissue of the trunks of several trees at each site and at various depths in the soil. Data were stored on a data logger at intervals of either 1 or 2 hours. The majority of the data were acquired between early 1994 and early 1995. The primary product of this data set is the diurnal stem temperature measurements acquired for selected trees at five BOREAS tower sites. The data are provided in tabular ASCII format. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Zimmerman, Reiner; McDonald, Kyle C.; Way, JoBea; Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Smith, David E. (Technical Monitor)

2000-01-01

122

Capital Punishment 1997  

NSDL National Science Digital Library

Recently released by the US Department of Justice's Bureau of Justice Statistics, this report presents capital punishment data for 1997 as well as preliminary data on executions in 1998. The report finds that in 1997, 3,335 men and women were on death row in 34 states, and during the year, seventeen states executed 74 prisoners -- all male -- with half of the executions occurring in Texas. Tabular data in the report display prisoners' sex, race, education, marital status, age, and method of execution, and the time between the imposition of the death sentence and execution. The report also includes historical tables that provide data on the 4,291 prisoners executed in the US between 1930 and 1997. The report is available in .pdf and ASCII format. Spreadsheets may be downloaded as a .zip file.

1999-01-01

123

mmView: a web-based viewer of the mmCIF format  

PubMed Central

Background Structural biomolecular data are commonly stored in the PDB format. The PDB format is widely supported by software vendors because of its simplicity and readability. However, the PDB format cannot fully address many informatics challenges related to the growing amount of structural data. To overcome the limitations of the PDB format, a new textual format mmCIF was released in June 1997 in its version 1.0. mmCIF provides extra information which has the advantage of being in a computer readable form. However, this advantage becomes a disadvantage if a human must read and understand the stored data. While software tools exist to help to prepare mmCIF files, the number of available systems simplifying the comprehension and interpretation of the mmCIF files is limited. Findings In this paper we present mmView - a cross-platform web-based application that allows to explore comfortably the structural data of biomacromolecules stored in the mmCIF format. The mmCIF categories can be easily browsed in a tree-like structure, and the corresponding data are presented in a well arranged tabular form. The application also allows to display and investigate biomolecular structures via an integrated Java application Jmol. Conclusions The mmView software system is primarily intended for educational purposes, but it can also serve as a useful research tool. The mmView application is offered in two flavors: as an open-source stand-alone application (available from http://sourceforge.net/projects/mmview) that can be installed on the user's computer, and as a publicly available web server.

2011-01-01

124

Comparison of abundances of chemical elements in mineralized and unmineralized sandstone of the Brushy Basin Member of the Morrison Formation, Smith Lake District, Grants uranium region, New Mexico  

USGS Publications Warehouse

Statistical treatment of analytical data from the Mariano Lake and Ruby uranium deposits in the Smith Lake district, New Mexico, indicates that organic carbon, arsenic, barium, calcium, cobalt, copper, gallium, iron, lead, manganese, molybdenum, nickel, selenium, strontium, sulfur, vanadium, yttrium, and zirconium are concentrated along with uranium in primary ore. Comparison of the Smith Lake data with information from other primary deposits in the Grants uranium region and elsewhere in the Morrison Formation of the Colorado Plateau suggests that these elements, with the possible exceptions of zirconium and gallium and with the probable addition of aluminum and magnesium, are typically associated with primary, tabular uranium deposits. Chemical differences between the Ruby and Mariano Lake deposits are consistent with the interpretation that the Ruby deposit has been more affected by post-mineralization oxidizing solutions than has the Mariano Lake deposit.

Pierson, C. T.; Spirakis, C. S.; Robertson, J. F.

1983-01-01

125

BOREAS TGB-9 Above-canopy NMHC at SSA-OBS, SSA-OJP, and SSA-OA Sites  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-9 team collected data in order to inventory and quantify the anthropogenic and biogenic NMHCs over the BOREAS study areas. This data set contains concentration and mixing ratio values for several NMHCs collected at the BOREAS SSA from 27-May-1994 to 15-Sep-1994. The data are provided in tabular ASCII files.

Keiser, B. N.; Niki, H.; Young, V. L.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

126

BOREAS TF-9 SSA-OBS Tower Flux, Meteorological, and Soil Temperature Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-9 team collected energy, carbon dioxide, and water vapor flux data at the BOREAS SSA-OBS site during the growing season of 1994 and most of the year for 1996. From the winter of 1995 to 1996, soil temperature data were also collected and provided. The data are available in tabular ASCII files.

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Massheder, Jonathan M.; Moncrieff, John B.; Rayment, Mark B.; Jarvis, Paul G.

2000-01-01

127

BOREAS TF-8 NSA-OJP Tower Flux, Meteorological, and Soil Temperature Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-8 team collected energy, CO2, and water vapor flux data at the BOREAS NSA-OJP site during the growing season of 1994 and most of the year for 1996. The data are available in tabular ASCII files.

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Moore, Kathleen E.; Fitzjarrald, David R.

2000-01-01

128

BOREAS TF-7 SSA-OBS Tower Flux and Meteorological Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-7 team collected meteorological data as well as energy, carbon dioxide, water vapor, methane, and nitrous oxide flux data at the BOREAS SSA-OBS site. The data were collected from 24-May to 19-Sep-1994. The data are available in tabular ASCII files.

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Pattey, Elizabeth; Desjardins, Raymond L.

2000-01-01

129

BOREAS TF-4 SSA-YJP Tower Flux, Meteorological, and Canopy Condition Data  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-4) team collected energy, carbon dioxide, and water vapor flux data at the BOREAS Southern Study Area-Young Jack Pine (SSA-YJP) site during the growing season of 1994. In addition, meteorological data were collected both above and within the canopy. The data are available in tabular ASCII files.

Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

130

BOREAS TF-5 SSA-OJP Tower Flux and Meteorological Data  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-5) team collected tower flux data at the BOREAS Southern Study Area Old Jack Pine (SSA-OJP) site through the growing season of 1994. The data are available in tabular ASCII files.

Baldocchi, Dennis; Vogel, Christoph; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

131

BOREAS TF-1 SSA-OA Understory Flux, Meteorological, and Soil Temperature Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-1 team collected energy, carbon dioxide, and momentum flux data under the canopy along with meteorological and soils data at the BOREAS SSA-OA site from mid-October to mid-November of 1993 and throughout all of 1994. The data are available in tabular ASCII files.

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Black, T. Andrew; Chen, Z.; Nesic, Zoran

2000-01-01

132

BOREAS TF-1 SSA-OA Tower Flux, Meteorological, and Soil Temperature Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-1 team collected energy, carbon dioxide, and momentum flux data above the canopy along with meteorological and soils data at the BOREAS SSA-OA site from mid-April to the end of the year for 1996. The data are available in tabular ASCII files.

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Black, T. Andrew; Chen, Z.; Nesic, Zoran

2000-01-01

133

BOREAS TGB-10 Volatile Organic Carbon Data over the SSA  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured VOC concentrations. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files.

Westberg, Hal; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Hall, Brad; Jackson, Andrea V.

2000-01-01

134

BOREAS RSS-2 Extracted Reflectance Factors Derived from ASAS Imagery  

NASA Technical Reports Server (NTRS)

The BOREAS RSS-2 team derived atmospherically corrected bidirectional reflectance factor means from multispectral, multiangle ASAS imagery for small homogeneous areas near several BOREAS sites. The ASAS imagery was acquired from the C-130 aircraft platform in 1994 and 1996. The data are stored in tabular ASCII files.

Russell, C.; Hall, Forrest G. (Editor); Nickerson, Jaime (Editor); Dabney, P.; Kovalick, W.; Graham, D.; Bur, Michael; Irons, James R.; Tierney, M.

2000-01-01

135

BOREAS TF-6 SSA-YA Surface Energy Flux and Meteorological Data  

NASA Technical Reports Server (NTRS)

The BOREAS TF-6 team collected surface energy flux and meteorology data at the SSA-YA site. The data characterize the energy flux and meteorological conditions at the site from 18-Jul to 20-Sep-1994. The data set does not contain any trace gas exchange measurements. The data are available in tabular ASCII files.

Bessemoulin, Pierre; Puech, Dominique; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

136

The digital geologic map of Colorado in ARC/INFO format  

USGS Publications Warehouse

This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

Green, Gregory N.

1992-01-01

137

The digital geologic map of Colorado in ARC/INFO format, Part A. Documentation  

USGS Publications Warehouse

This geologic map was prepared as a part of a study of digital methods and techniques as applied to complex geologic maps. The geologic map was digitized from the original scribe sheets used to prepare the published Geologic Map of Colorado (Tweto 1979). Consequently the digital version is at 1:500,000 scale using the Lambert Conformal Conic map projection parameters of the state base map. Stable base contact prints of the scribe sheets were scanned on a Tektronix 4991 digital scanner. The scanner automatically converts the scanned image to an ASCII vector format. These vectors were transferred to a VAX minicomputer, where they were then loaded into ARC/INFO. Each vector and polygon was given attributes derived from the original 1979 geologic map. This database was developed on a MicroVAX computer system using VAX V 5.4 nd ARC/INFO 5.0 software. UPDATE: April 1995, The update was done solely for the purpose of adding the abilitly to plot to an HP650c plotter. Two new ARC/INFO plot AMLs along with a lineset and shadeset for the HP650C design jet printer have been included. These new files are COLORADO.650, INDEX.650, TWETOLIN.E00 and TWETOSHD.E00. These files were created on a UNIX platform with ARC/INFO 6.1.2. Updated versions of INDEX.E00, CONTACT.E00, LINE.E00, DECO.E00 and BORDER.E00 files that included the newly defined HP650c items are also included. * Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Descriptors: The Digital Geologic Map of Colorado in ARC/INFO Format Open-File Report 92-050

Green, Gregory N.

1992-01-01

138

Structure Formation in Astrophysics  

NASA Astrophysics Data System (ADS)

Part I. Physical Processes and Numerical Methods Common to Structure Formations in Astrophysics: 1. The physics of turbulence E. Levêque; 2. The numerical simulation of turbulence W. Schmidt; 3. Numerical methods for radiation magnetohydrodynamics in astrophysics R. Klein and J. Stone; 4. The role of jets in the formation of planets, stars, and galaxies R. Banerjee, R. Pudritz and R. Ouyed; 5. Advanced numerical methods in astrophysical fluid dynamics A. Hujeirat and F. Heitsch; Part II. Structure and Star Formation in the Primordial Universe: 6. New frontiers in cosmology and galaxy formation challenges for the future R. Ellis and J. Silk; 7. Galaxy formation physics T. Abel, G. Bryan and R. Teyssier; 8. First stars formation, evolution, feedback effects V. Bromm, A. Ferrara and A. Heger; Part III. Contemporary Star and Brown Dwarf Formation: a) Cloud Formation and Fragmentation: 9. Diffuse interstellar medium and the formation of molecular clouds P. Hennebelle, M. Mac Low and E. Vazquez-Semadeni; 10. The formation of distributed and clustered stars in molecular clouds T. Megeath, Z. -Y. Li and A. Nordlund; b) Core Fragmentation and Star Formation: 11. The formation and evolution of prestellar cores P. André, S. Basu and S. Inutsuka; 12. Models for the formation of massive stars; Part IV. Protoplanetary Disks and Planet Formation M. Krumholz and I. Bonnell: 13. Observational properties of disks and young stellar objects G. Duchêne, F. Ménard, J. Muzzerolle and S. Mohanty; 14. Structure and dynamics of protoplanetary disks C. Dullemond, R. Durisen and J. Papaloizou; 15. Planet formation and evolution theory and observation Y. Alibert, I. Baraffe, W. Benz, G. Laughlin and S. Udry; 16. Planet formation assembling the puzzle G. Wurm and T. Guillot; Part V. Summary: 17. Open issues in small- and large-scale structure formation R. Klessen and M. Mac Low; 18. Final word E. Salpeter.

Chabrier, Gilles

2011-02-01

139

Structure Formation in Astrophysics  

NASA Astrophysics Data System (ADS)

Part I. Physical Processes and Numerical Methods Common to Structure Formations in Astrophysics: 1. The physics of turbulence E. Levêque; 2. The numerical simulation of turbulence W. Schmidt; 3. Numerical methods for radiation magnetohydrodynamics in astrophysics R. Klein and J. Stone; 4. The role of jets in the formation of planets, stars, and galaxies R. Banerjee, R. Pudritz and R. Ouyed; 5. Advanced numerical methods in astrophysical fluid dynamics A. Hujeirat and F. Heitsch; Part II. Structure and Star Formation in the Primordial Universe: 6. New frontiers in cosmology and galaxy formation challenges for the future R. Ellis and J. Silk; 7. Galaxy formation physics T. Abel, G. Bryan and R. Teyssier; 8. First stars formation, evolution, feedback effects V. Bromm, A. Ferrara and A. Heger; Part III. Contemporary Star and Brown Dwarf Formation: a) Cloud Formation and Fragmentation: 9. Diffuse interstellar medium and the formation of molecular clouds P. Hennebelle, M. Mac Low and E. Vazquez-Semadeni; 10. The formation of distributed and clustered stars in molecular clouds T. Megeath, Z. -Y. Li and A. Nordlund; b) Core Fragmentation and Star Formation: 11. The formation and evolution of prestellar cores P. André, S. Basu and S. Inutsuka; 12. Models for the formation of massive stars; Part IV. Protoplanetary Disks and Planet Formation M. Krumholz and I. Bonnell: 13. Observational properties of disks and young stellar objects G. Duchêne, F. Ménard, J. Muzzerolle and S. Mohanty; 14. Structure and dynamics of protoplanetary disks C. Dullemond, R. Durisen and J. Papaloizou; 15. Planet formation and evolution theory and observation Y. Alibert, I. Baraffe, W. Benz, G. Laughlin and S. Udry; 16. Planet formation assembling the puzzle G. Wurm and T. Guillot; Part V. Summary: 17. Open issues in small- and large-scale structure formation R. Klessen and M. Mac Low; 18. Final word E. Salpeter.

Chabrier, Gilles

2009-01-01

140

Interstratified arkosic and volcanic rocks of the Miocene Spanish Canyon Formation, Alvord Mountain area, California: descriptions and interpretations  

USGS Publications Warehouse

The Spanish Canyon Foundation in the Alvord Mountain area, California, varies from about 50 to 120 m thick and records the interstratification of arkosic sandstone and conglomerate with tuffaceous deposits and lava flows. In the lower third of the formation, arkosic sandstone and conglomerate are interstratified with tuffaceous deposits. Some tuffs might have been deposited as primary, nonwelded to partially welded ignimbrites or fallout tephra. Many of the tuffaceous deposits represent redeposited material that formed tuffaceous sandstone, and many of these deposits contain arkosic grains that represent mixing of different source matieral. Arkosic sandstone, and especially conglomerate (some with maximum clast lengths up to 1 m), represent intermittent incursions of coarser plutoniclastic fan deposits into other finer grained and mostly volcaniclastic basin deposits. After deposition of the 18.78 Ma Peach Spring Tuff, the amount of tuffaceous material decreased. The upper two-thirds of the formation has arkosic sandstone and conglomerate interstratified with two olivine basalt lave flows. locally, conglomerate clasts in this part of the section have maximum lengths up to 1 m. Many tuffaceous and arkosic sandstone beds of the Spanish Canyon Formation have tabular to broad (low-relief) lenticular geometry, and locally, some arkosic conglomerate fills channels as much as 1.5 m deep. These bedforms are consistent with deposition in medial to distal alluvial-fan or fluvial environments; some finer-grained deposits might have formed in lacustrine environments.

Buesch, David C.

2014-01-01

141

Significance of microbialites, calcimicrobes, and calcareous algae in reefal framework formation from the Silurian of Gotland, Sweden  

NASA Astrophysics Data System (ADS)

The structure of stromatoporoid-tabulate coral reefs from the Mid- to Upper Silurian of Gotland includes complex microbialite and algal framework fabric. Non-skeletal microbialites show variable fabrics, structures, and morphologies ranging from largely non-laminated, peloidal, irregular masses to well-laminated stromatolite crusts, indicated by convex upwardly oriented overgrowth structures, trichome-like arrangement of peloids and intergrowth with skeletal calcimicrobes and metazoans. Non-skeletal microbialites contribute to framework formation during different stages in the Högklint reef development as well as in the marginal, or flanking beds of stromatoporoid-coral patch reefs in the Tofta Formation. In addition to non-skeletal microbialites, calcimicrobes (mainly Rothpletzella) and coralline algae ( Graticula gotlandica) substantially contribute to framework formation in reefs from the Högklint and the lower Hamra Formation. Depending on the occurrence pattern and abundance of microbialites, calcimicrobes, and calcareous algae, four framework types can be differentiated based on the environmental setting. Type (1)—a tabular stromatoporoid and non-skeletal microbialite framework, characteristic for lower and intermediate parts of the Högklint reefs, developed in slightly deeper, lower energy, fully marine conditions. Type (2)—a graticulacean-microbial/calcimicrobial framework, typically developed in the upper and top parts of the Högklint reefs, marking shallow, moderate to highly agitated water. Type (3)—a stromatolite- Coenites framework, being part of the reef development in the Tofta Formation. Stromatolites formed in sheltered, partly restricted parts of stromatoporoid-coral patch reef complexes. Type (4)—a stromatoporoid-calcimicrobial framework, forming relatively small reef bodies in the lower Hamra Formation, situated in a highly agitated, very shallow, open marine environment. These examples indicate that microbial crusts, calcimicrobes, and graticulacean algae were more important contributors to framework formation in Silurian metazoan reefs than previously thought.

Nose, Martin; Schmid, Dieter U.; Leinfelder, Reinhold R.

2006-12-01

142

Star Formation in Galaxies  

NASA Technical Reports Server (NTRS)

Topics addressed include: star formation; galactic infrared emission; molecular clouds; OB star luminosity; dust grains; IRAS observations; galactic disks; stellar formation in Magellanic clouds; irregular galaxies; spiral galaxies; starbursts; morphology of galactic centers; and far-infrared observations.

1987-01-01

143

Advanced Formation Flight Control.  

National Technical Information Service (NTIS)

In this thesis, the formation flight control problem is continued from four previous theses. Automatic formation flight involves controlling multiple aircraft equipped with standard Mach-hold, altitude hold, and heading-hold autopilots to maintain a desir...

M. J. Veth

1994-01-01

144

Optimal Formation Flight Control.  

National Technical Information Service (NTIS)

Automatic formation flight involves controlling multiple wing aircraft equipped with standard Mach-hold, altitude-hold, and heading-hold autopilots in order to maintain a desired position relative to a lead aircraft throughout formation maneuvers. Changes...

S. B. McCamish

1995-01-01

145

The Format Dilemma.  

ERIC Educational Resources Information Center

Reports results of a survey of public libraries that investigated trends in audiovisual materials. Highlights include format issues; audiobooks; media budgets for various formats; video collections; DVDs; circulation; collection sizes; music CDs; and future possibilities. (LRW)

Oder, Norman

2002-01-01

146

Close Formation Flight Control.  

National Technical Information Service (NTIS)

In this research the close formation flight control problem is addressed. The formation consists of a lead and wing aircraft, where the wing flies in close formation with the lead, such that the lead's vortices produce aerodynamic coupling effects, and a ...

A. W. Proud

1999-01-01

147

Autonomous formation flight  

Microsoft Academic Search

This article describes an approach to close-formation flight of autonomous aircraft. A standard LQ-based structure was synthesized for each vehicle and for formation position error control using linearized equations of motion and a lifting line model of the aircraft wake. We also consider the definition of a formation management structure, capable of dealing with a variety of generic transmission and

F. Giulietti; L. Pollini; M. Innocenti

2000-01-01

148

Medical image file formats.  

PubMed

Image file format is often a confusing aspect for someone wishing to process medical images. This article presents a demystifying overview of the major file formats currently used in medical imaging: Analyze, Neuroimaging Informatics Technology Initiative (Nifti), Minc, and Digital Imaging and Communications in Medicine (Dicom). Concepts common to all file formats, such as pixel depth, photometric interpretation, metadata, and pixel data, are first presented. Then, the characteristics and strengths of the various formats are discussed. The review concludes with some predictive considerations about the future trends in medical image file formats. PMID:24338090

Larobina, Michele; Murino, Loredana

2014-04-01

149

Tropical cyclone formation  

SciTech Connect

The physics of tropical cyclone formation is not well understood, and more is known about the mature hurricane than the formative mechanisms that produce it. It is believed part of the reason for this can be traced to insufficient upper-level atmospheric data. Recent observations suggest that tropical cyclones are initiated by asymmetric interactions associated with migratory upper-level potential vorticity disturbances and low-level disturbances. Favored theories of cyclones formation, however, focus on internal processes associated with cumulus convection and/or air-sea interaction. This work focuses on external mechanisms of cyclone formation and, using both a two- and three-dimensional moist geostrophic momentum model, investigates the role of upper-level potential vorticity disturbances on the formation process. A conceptual model of tropical cyclone formation is proposed, and implications of the theory are discussed. 71 refs., 5 figs., 1 tab.

Montgomery, M.T.; Farrell, B.F. (Harvard Univ., Cambridge, MA (United States))

1993-01-15

150

DBP formation during chloramination  

Microsoft Academic Search

Batch experiments were conducted on three diverse water sources to study the formation of dissolved organic halogen (DOX), trihalomethanes (THMs), haloacetic acids (HAAs), and cyanogen halides (CNX) during chloramination. The authors used preformed chloramines to examine the effect of pH, mass ratio of chlorine to ammonia-nitrogen (Cl? to N), and bromide concentration on disinfection by-product (DBP) formation. Formation of specific

Alicia C. Diehl; Gerald E. Speitel Jr.; James M. Symons; Stuart W. Krasner; Cordelia J. Hwang; Sylvia E. Barrett

2000-01-01

151

Flash Open File Format  

NSDL National Science Digital Library

Macromedia has released the file format specification for its Flash (discussed in the April 11, 1997 Scout Report) multimedia web tool. Flash allows web developers to create vector based graphics and animation. By making the format (.swf) available, Macromedia hopes to establish it as a standard for vector graphics and animation. The company claims it will "submit the format specification to a recognized Internet standards organization." In addition to providing the file format specification, the site provides Flash related news releases, a Flash FAQ, and a vector graphics white paper.

152

Three Dimensional Formation Flight Control.  

National Technical Information Service (NTIS)

Automating the control of an aircraft flying in formation necessitates the extension of the theory of formation flight control to allow for three dimensional maneuvers. The formation was modeled as a two-aircraft, leader and wingspan, formation. Both airc...

J. K. Hall

2000-01-01

153

Entering the Formative Years  

ERIC Educational Resources Information Center

This article discusses formative assessment--classroom strategies that ensure students are understanding music concepts. Unlike summative assessments (end-of-process evaluations like final exams, SATs, or auditions), formative assessments need to be non-threatening, helpful, and most of all, effective. The process starts with a teacher…

Powers, Keith

2011-01-01

154

Ribbed moraine formation  

Microsoft Academic Search

Ribbed (Rogen) moraines are conspicuous landforms found in interior parts of formerly glaciated areas. Two major theories for ribbed moraine formation have been suggested in recent years: (i) the shear and stack theory, which explains ribbed moraine formation by shearing and stacking of till slabs or englacially entrained material during compressive flow, followed by basal melt-out of transverse moraine ridges,

Clas Hättestrand; Johan Kleman

1999-01-01

155

Formative Assessment Probes  

ERIC Educational Resources Information Center

Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

Eberle, Francis; Keeley, Page

2008-01-01

156

Delayed ettringite formation  

Microsoft Academic Search

Delayed ettringite formation (DEF) can damage concrete that has experienced a temperature above about 70°C. Claims that slow release of sulfate from the clinker can have a similar effect in concrete not thus heated are unsupported. Chemical and microstructural aspects of DEF are reviewed. Expansion results from formation of ettringite crystals of submicrometre size in the paste, the larger crystals

H. F. W Taylor; C Famy; K. L Scrivener

2001-01-01

157

Formation of giant planets  

NASA Astrophysics Data System (ADS)

We present calculations of giant planet formation based on extended core-accretion planet formation models taking into account disk structure and evolution and migration of the protoplanet. We show that these models lead to giant planet formation timescales compatible with disk lifetimes. Using these models, we show that we can reproduce the bulk internal structure of Jupiter and Saturn, as well as the enrichment in volatile species measured in situ by the Galileo probe (for Jupiter), and from the Earth (for Saturn). We then apply these models to the formation of the three Neptune mass planet system recently discovered by the HARPS collaboration (Lovis et al. 2006), and show that the two outer planets are likely to have accreted large amounts of water ice during their formation. Finally, the comparison with the extrasolar planets will be presented by C. Mordasini (this meeting, abstract EPSC2006-A-00672) using a Monte-Carlo approach.

Alibert, Y.; Mordasini, C.; Benz, W.

158

Formation of Planetesimals.  

National Technical Information Service (NTIS)

Formation of planetesimals is discussed. The following subject areas are covered: (1) nebular structure; (2) aerodynamics of the solid bodies in the nebula; (3) problems with gravitational instability; (4) particle growth by coagulation; properties of fra...

S. J. Weidenschilling

1991-01-01

159

Formation of Hurricanes  

NSDL National Science Digital Library

This is a picture inquiry based lesson for students to explore the formation of hurricanes. Groups of three students will observe and explain trends found in a picture and share ideas with their peers.

Morgan, Amber

2012-08-10

160

Revised nomenclature and stratigraphic relationships of the Fredericksburg Complex and Quantico Formation of the Virginia Piedmont  

USGS Publications Warehouse

The Fredericksburg Complex, in part a migmatitic terrane in northeast Virginia, is subdivided on the basis of lithology, as well as aeromagnetic and aeroradiometric data, into two metamorphic suites. These suites are separated by the northeast-trending Spotsylvania lineament, a rectilinear geophysical feature that is probably the trace of an old fault zone. East of the lineament, the Po River Metamorphic Suite, of Proterozoic Z and (or) early Paleozoic age, consists dominantly of biotite gneiss, generally augen gneiss, and lesser amounts of hornblende gneiss and mica schist. West of the Spotsylvania lineament is the Ta River Metamorphic Suite, composed mostly of amphibolite and amphibole gneiss. However, to the southwest, along its strike belt, the Ta River contains abundant biotite gneiss and mica schist. Both the Ta River and Po River contain abundant foliated granitoid and pegmatoid bodies as concordant tabular masses and as crosscutting dikes; these rocks are considered part of the Ta River and Po River Metamorphic Suites. The amphibolitic Holly Corner Gneiss is interpreted to be a western allochthonous equivalent of the Ta River. Both the Ta River and Holly Corner are considered to be coeval, eastern, distal facies of the Lower Cambrian(?) Chopawamsic Formation. The Paleozoic Falls Run Granite Gneiss intrudes the Ta River Metamorphic Suite and the Holly Corner Gneiss; locally the Falls Run is interpreted to have been transported westward with the Holly Corner after intrusion. The Quantico Formation, in the core of the Quantico-Columbia synclinorium, rests with angular unconformity along its northwest and southeast limbs, respectively, on the Chopawamsic Formation and the Ta River Metamorphic Suite. The Quantico Formation is assigned the same Late Ordovician age and similar stratigraphic position as the Arvonia Slate of the Arvonia syncline. The youngest rocks of the area are the granitoid and pegmatoid bodies of the Falmouth Intrusive Suite. They consist of several generations of chiefly dikes and sills that are intrusive into the Fredericksburg Complex and into the Quantico Formation. Granitoid rocks also form small plutons. The Falmouth is isotopically dated as Carboniferous in age. Some of the metavolcanic rocks of the Evington Group and part of the amphibolite gneiss and amphibolite of the Hatcher Complex, named by W. B. Brown in 1969, are probably coeval with the Chopawamsic Formation and hence equivalents of the Ta River Metamorphic Suite and the Holly Corner Gneiss. The biotitic gneiss and granitoid rocks east of the Spotsylvania lineament in the Dillwyn area are considered to be coeval with the Po River Metamorphic Suite.

Pavlides, Louis

1980-01-01

161

Plant Formate Dehydrogenase  

SciTech Connect

The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

John Markwell

2005-01-10

162

Display formats manual  

NASA Technical Reports Server (NTRS)

The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

Runnels, R. L.

1973-01-01

163

Palaeoenvironmental analysis of the Late Proterozoic Nagthat Formation, NW Kumaun Lesser Himalaya, India  

NASA Astrophysics Data System (ADS)

The Late Proterozoic Nagthat Formation (˜ 750 m) of the Jaunsar Group exhibits extensive development of multistoried medium- to thick-bedded sandstone, impersistent conglomerate (pebbly beds) and siltstone-shale. It represents a shoreface to a proximal inner-shelf deposit, developed under the dominant influence of tidal and occasional storm conditions. The major lithofacies recognised are the following. (a) The coarse-grained siliciclastic facies (CGS), represented by discontinuous beds of coarse-grained sandstone with lenses of conglomerates. The important sedimentary features observed in this facies are medium- to large-scale trough, tabular cross-stratifications and crudely graded conglomerates etc. The coarse-grained sandstone is frequently punctuated by numerous broadly undulatory or locally more or less flat erosional surfaces. A proximal shoreface environmental set-up has been assigned to this facies. (b) The interbedded medium- to fine-grained siliciclastic facies (IMFS), consisting of decimetre- to metre-thick alternations of medium- to fine-grained subarkosic to sublithic arenite with subordinate quartz arenite and quartz wacke. The striking sedimentary features are the herringbone cross-stratification and rare hummocky cross-stratification (HCS). The rareness of the HCS suggests a frequent reworking of storm-laden sediments by fair-weather processes in the intermediate shoreface zone. (c) The fine-grained siliciclastic facies (FGS) represented by parallel to cross-laminated silty sandstone and shale, is interpreted as the distal shoreface to proximal inner-shelf deposit. The study of these facies reveals the three prominent associations, viz., fining upward CGS-IMFS-FGS and CGS-FGS, and coarsening upward FGS-IMFS. The first two facies associations have resulted mainly from tidal activity, whereas the last one provides evidence of storm activity. The overall coarsening upward stratigraphic sequence suggests gradual shallowing of the basin and thus indicates a prograding behaviour of the Nagthat Formation.

Ghosh, Sumit K.

1991-04-01

164

Contaminant Transport in the Highly Heterogeneous Sedimentary Formation at Canadian Forces Base Borden, Ontario, Canada  

NASA Astrophysics Data System (ADS)

Based on results of detailed geostatistical characterization of a sand quarry located two km from the Stanford-Waterloo site at Canadian Forces Base Borden, Ontario, Canada, and evaluation of material properties at this site, we show that the succession is highly heterogeneous with variance of log-conductivity as large as 17.9. The main goal of the present research is to identify key parameters that would impact solute plume transport, and especially tailing, through this formation. The identification, accomplished through modeling, is based on sensitivity analyses. The heterogeneity model adopted here is a special case of a general multi-indicator model, which has been extensively used in the past in stochastic modeling of plume transport and tailing in heterogeneous formations. The present model contains four types of randomly placed 3D oblate ellipsoidal inclusions (e.g. geological lenses) that represent different materials found at the site: gravel, lenticular sands, tabular sands, and clay. Inclusion sizes and volume fractions are determined through indicator geostatistical analysis. A constant hydraulic conductivity and linear sorption distribution coefficient are assigned to each type of inclusion for each simulation. Plume transport and tailing are quantified using break-through curves for a set of equally spaced control planes. Sensitivity analyses of the effect of inclusion sizes, volume fractions and properties on break-through curves are conducted to quantify contaminant tailing and to identify key parameters influencing the tailing. The preliminary results indicate that slow advection and diffusion through clay lenses are the main causes of the plume spreading and can produce plume tailing for several decades or longer.

Maghrebi, M.; Jankovic, I.; Allen-King, R. M.; Weissmann, G. S.; Rabideau, A. J.

2013-12-01

165

Autonomous Formation Flight  

NASA Technical Reports Server (NTRS)

NASA's Strategic Plan for the Aerospace Technology Enterprise includes ambitious objectives focused on affordable air travel, reduced emissions, and expanded aviation-system capacity. NASA Dryden Flight Research Center, in cooperation with NASA Ames Research Center, the Boeing Company, and the University of California, Los Angeles, has embarked on an autonomous-formation-flight project that promises to make significant strides towards these goals. For millions of years, birds have taken advantage of the aerodynamic benefit of flying in formation. The traditional "V" formation flown by many species of birds (including gulls, pelicans, and geese) enables each of the trailing birds to fly in the upwash flow field that exists just outboard of the bird immediately ahead in the formation. The result for each trailing bird is a decrease in induced drag and thus a reduction in the energy needed to maintain a given speed. Hence, for migratory birds, formation flight extends the range of the system of birds over the range of birds flying solo. The Autonomous Formation Flight (AFF) Project is seeking to extend this symbiotic relationship to aircraft.

Schkolnik, Gerard S.; Cobleigh, Brent

2004-01-01

166

Formation of the earth  

NASA Technical Reports Server (NTRS)

The origin of the earth is discussed in the context of the formation of the sun and the planets, and a standard model for such a formation assuming gravitational instability in a dense interstellar molecular cloud is outlined, along with the most significant variant of the model in which the loss of the nebular gas occurred after the formation of the earth. The formation of the sun and solar nebulae is addressed, and the coagulation of grains and the formation of small planetesimals are covered, along with the gravitational accumulation of planetesimals into planetary embryos and final stages of accumulation - embryos of planets. It is pointed out that the final stage of accumulation consists of the collision of these embryos; because of their large size, particularly after their further growth, these collisions represent giant impacts. It is concluded that the earth was initially an extremely hot and melted planet, surrounded by a fragile atmosphere and subject to violent impacts by bodies of the size of Ceres and even the moon.

Wetherill, George W.

1990-01-01

167

GenBank at Los Alamos: User manual, training guide, and reference manual for the ASCII AWB  

SciTech Connect

The GenBank project at Los Alamos collects nucleotide sequence submissions from the biological research community. This work includes the processing of data received in several different forms as well as maintenance and quality control on those submissions. This manual explains the procedures involved in that work for both Los Alamos GenBank staff and off-site users. The GenBank database stores annotated DNA sequences. This manual contains the procedures for depositing these sequences into the database. There are two ways to do this. Either the sequence arrives at GenBank as a submission and is entered by the database staff or the sequence is directly entered by an off-site user. The Annotator's WorkBench (AWB), which is a database browsing and editing tool, is used in both cases. This manual is for GenBank staff and off-site users of the GenBank database at the Los Alamos National Laboratory. It contains an introduction and tutorials for AWB, as well as procedures for entering sequences either as submissions or as data directly deposited by an off-site user. Instructions for all of these are found in Chapters 2 through 4. The introduction to AWB is in Chapter 2. Instructions for submission handling are in Chapter 3. Instructions for entering sequence information are in Chapter 4. Off-site users should look at section 4.3 for instructions on entering a sequence. In addition, the manual describes various in-house curatorial tasks that are part of maintaining the database, as well as the procedures and conventions for annotating sequences. The procedures for annotation and review are in Chapters 5 and 6. The description of in-house curator's tasks is in Chapter 7. The appendices contain: Annotation conventions, two reference chapters on AWB and other utility programs, a complete list of all the forms, fields, and commands in AWB and descriptions of other (non-AWB) software utilities used by database staff.

Reese, G.C.; Keen, G.M.; Gilna, P.; Cinkosky, M.J.

1993-03-15

168

Family formation and urbanization.  

PubMed

"This article will deal with two stages in the family life course: formation of the couple through marriage, and the birth of successive children.... We shall investigate whether migration into or out of a metropolitan area modifies the formation of the family, and conversely whether the different stages in family formation modify migration behaviour....First, using a nonparametric approach, we shall consider the sequence of events throughout an individual's life-course, and thereby demonstrate how the occurrence of one life-event alters the probability of the occurrence of others." Next, a semiparametric approach is used to analyze the impact of variables such as educational level, occupational level, and social class on marriage, fertility, and migration. The geographic focus is on France. PMID:12157901

Courgeau, D

1989-09-01

169

Formation of tectonic peperites from alkaline magmas intruded into wet sediments in the Beiya area, western Yunnan, China  

USGS Publications Warehouse

Tertiary (3.78 Ma to 3.65 Ma) biotite-K-feldspar porphyritic bodies intrude Tertiary, poorly consolidated lacustrine sedimentary rocks in the Beiya mineral district in southwestern China. The intrusives are characterized by a microcrystalline and vitreous-cryptocrystalline groundmass, by replacement of some tabular K-feldspar phenocrysts with microcrystalline chlorite and calcite, and by Fe-rich rings surrounding biotite phenocrysts. Peculiar structures, such as contemporary contact faults and slickensides, ductile shear zones and flow folds, foliation and lineations, tension fractures, and banded and boudin peperites, are developed along the contact zones of the intrusives. These features are related to the forceful intrusion of the alkaline magmas into the wet Tertiary sediments. The partially consolidated magmas were deformed and flattened by continued forceful magma intrusion that produced boudinaged and banded peperites. These peperites characterized by containing oriented deformation fabrics are classified as tectonic peperites as a new type of peperite, and formation of these tectonic peperites was related to fracturing of magmas caused by forceful intrusion and shear deformation and to contemporary migration and injection of fluidized sediments along fractures that dismembered the porphyritic magma. Emplacement of the magma into the wet sediments in the Beiya area is interpreted to be related to a large pressure difference rather than to the buoyancy force. ?? 2007 Elsevier Ltd. All rights reserved.

Xu, X. -W.; Cai, X. -P.; Zhong, J. -Y.; Song, B. -C.; Peters, S. G.

2007-01-01

170

An Upper Turonian fine-grained shallow marine stromatolite bed from the Muñecas Formation, Northern Iberian Ranges, Spain  

NASA Astrophysics Data System (ADS)

A fine-grained stromatolite bed, laterally continuous on the kilometer scale and with small synoptic relief, crops out in the Muñecas Formation in the Northern Iberian Ranges. The Muñecas Fm. was deposited during the late Turonian on a shallow water platform in the Upper Cretaceous intracratonic Iberian basin. The stromatolite bed has a tabular to domed biostromal macrostructure. Its internal mesostructure consists of planar, wavy to hemispherical stromatoids that display a broad spectrum of microstructures, including dense micrite, bahamite peloids, peloidal to clotted microfabrics, irregular micritic-wall tubes, which are suggestive of algae and filamentous microframeworks, which are suggestive of filamentous cyanobacteria. Various stromatolite growth stages have been linked to the dominance of different accretion processes. The accretion of the entire fine-grained stromatolite involves a complex mosaic of processes: trapping and binding of quartz-silt grains and bahamites, which form the agglutinated parts of some laminae, and microbially induced precipitation, which forms spongiostromic and micritic laminae. Tubiform and filamentous microframeworks resembling porostromatate or skeletal stromatolitic growth were also recognized. Laser ICP-MS measurements of Al, Si, Mg, Mn, Sr, S and Fe were analyzed to detect the influence of siliciclastic inputs and major trends during stromatolite accretion. Carbon and oxygen isotopic compositions from the stromatolite and associated facies were used to identify possible microbial signatures. These data describes a unique and well-preserved example of a shallow marine Upper Turonian fine-grained stromatolite.

Rodríguez-Martínez, M.; Sánchez, F.; Walliser, E. O.; Reitner, J.

2012-07-01

171

Neoproterozoic banded iron formations  

Microsoft Academic Search

Two epochs of the formation of ferruginous quartzites—Archean-Paleoproterozoic (3.2–1.8 Ga) and Neoproterozoic (0.85–0.7 Ga)—are\\u000a distinguished in the Precambrian. They are incommensurable in scale: the Paleoproterozoic Kursk Group of the Kursk Magnetic\\u000a Anomaly (KMA) extends over 1500 km, whereas the extension of Neoproterozoic banded iron formations (BIF) beds does not exceed\\u000a a few tens of kilometers. Their thickness is up to

A. V. Ilyin

2009-01-01

172

Primary Radiation Damage Formation  

SciTech Connect

The physical processes that give rise to changes in the microstructure, and the physical and mechanical properties of materials exposed to energetic particles are initiated by essentially elastic collisions between atoms in what has been called an atomic displacement cascade. The formation and evolution of this primary radiation damage mechanism are described to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the primary variables cascade energy and irradiation temperature are discussed, along with a range of secondary factors that can influence damage formation.

Stoller, Roger E [ORNL

2012-01-01

173

Wotsit's File Format Collection  

NSDL National Science Digital Library

Wotsit's File Format Collection, provided by Paul Oliver, features a very large number of file formats. These include JPEG image files, wave sound files, Rich Text files, and common database and word-processing files such as Paradox and Wordperfect. Documents collected or linked at the site are primarily either original specifications from the creator or an improved version of the original. All of the specifications are very technical and are directed towards programmers. Users can subscribe to a mailing list for notification of site updates.

174

Isolating Triggered Star Formation  

SciTech Connect

Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.

Barton, Elizabeth J.; Arnold, Jacob A.; /UC, Irvine; Zentner, Andrew R.; /KICP, Chicago /Chicago U., EFI; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

2007-09-12

175

Cave Formation: Kane Cave  

NSDL National Science Digital Library

This video documents an experiment conducted in Kane Cave, Wyoming, to see if microbes that inhabit the cave could actually be contributing to the cave-formation process. Adapted from a NOVA broadcast, the segment is four minutes and twelve seconds in length.

2010-11-25

176

Oil Formation and Trapping  

NSDL National Science Digital Library

This animation shows the successive stages in the formation of an oil reserve. In View 1, organic material settles, is buried, and is transformed by heat and pressure into oil. In View 2 an oil trap is formed: the area folds into an anticline, and oil migrates and accumulates in the anticline crest.

Marshak, Stephen; Company, W. W.

177

Formation of planetesimals  

NASA Technical Reports Server (NTRS)

Formation of planetesimals is discussed. The following subject areas are covered: (1) nebular structure; (2) aerodynamics of the solid bodies in the nebula; (3) problems with gravitational instability; (4) particle growth by coagulation; properties of fractal aggregates; and (5) coagulation and settling of fractal aggregates.

Weidenschilling, Stuart J.

1991-01-01

178

Promoting habit formation  

Microsoft Academic Search

Habits are automatic behavioural responses to environmental cues, thought to develop through repetition of behaviour in consistent contexts. When habit is strong, deliberate intentions have been shown to have a reduced influence on behaviour. The habit concept may provide a mechanism for establishing new behaviours, and so healthy habit formation is a desired outcome for many interventions. Habits also however

Phillippa Lally; Benjamin Gardner

2011-01-01

179

Wound-Periderm Formation  

Microsoft Academic Search

Herbivores, and particularly chewing insects, cause substantial damage to the plant. In addition to lost tissue, there are great concerns of pathogen invasion and water loss at the site of the attack. One of the plant’s defense strategies is the formation of wound periderm at the boundaries of the invaded or damaged region to isolate it from non-wounded healthy tissue.

Idit Ginzberg

180

Localized Bluetooth Scatternet Formation  

Microsoft Academic Search

This paper addresses the problem of scatternet formation algorithm for multi-hop Bluetooth based personal area and ad hoc network, with minimal communication overhead. Nodes are assumed to know their position and are able to establish connections with any of the neighboring nodes. We first pro- pose a new sparse subgraph, namely, partial Delaunay triangulation (PDT), which can be constructed efficiently

XIANG-YANG LI

181

Supernova induced star formation  

Microsoft Academic Search

The evidence for the triggering of star formation by shocks from expanding supernova shells is examined with special emphasis on the solar system. It is shown that the recently discovered isotopic anomalies, mainly in Ti, can serve as the best signature for this purpose. It is suggested that the discovery of correlated anomalies in Ti, Fe, and Ca will give

S. Ramadurai

1986-01-01

182

The Formation of Trihalomethanes.  

ERIC Educational Resources Information Center

Reviewed are a number of factors important in the formation of trihalomethanes (THM) including the nature of aquatic humus and the influences of preozonation, bromide, pH, and chlorine. A brief investigation is also conducted into the kinetics of the THM reaction. Several major research needs are represented. (CS)

Trussell, R. Rhodes; Umphres, Mark D.

1978-01-01

183

Energetics of Core Formation  

Microsoft Academic Search

The loss of gravitational energy on core formation is calculated for the case of simple unmixing of two components, whose equations of state are found from the present density distribution. Without allowance for thermal expansion, the mean energy available for heating is 600 eal\\/g; with an approximate allowance for thermal expansion, this is re- dueed to 400 eal\\/g, which is

Francis Birch

1965-01-01

184

Formation of Giant Planets.  

National Technical Information Service (NTIS)

Under the support of NASA Origins grant, we studied the formation of gaps in protoplanetary disks due the tidal interaction between a fully grown protoplanet and protostellar disk. The result of this study is published in the Astrophysical Journal, (vol 5...

D. Lin

1999-01-01

185

Document Format Recognition.  

National Technical Information Service (NTIS)

This study is primarily concerned with methods for analyzing the format of pages from technical journals, and means for automatically processing the textual and graphic material on these pages for input to a computer which is to perform textual data proce...

S. B. Gray

1965-01-01

186

Computational Star Formation (IAU S270)  

NASA Astrophysics Data System (ADS)

1. Historical introduction; 2. Individual star formation: observations; 3. Low-mass star formation: observations; 4. Individual star formation: theory; 5. Formation of clusters: observations; 6. Formation of clusters: theory; 7. Numerical methods: MHD; 8. Numerical methods: radiative dynamics; 9. Local star formation processes; 10. Star formation feedback; 11. Star formation on galactic scales; 12. Special purpose hardware; 13. Computational methods; 14. Radiation diagnostics of star formation; 15. Large scale star formation; 16. Cosmological star formation; 17. Computational star formation: Summary; Index.

Alves, João.; Elmegreen, Bruce G.; Girart, Josep M.; Trimble, Virginia

2011-05-01

187

Pattern formation during vasculogenesis  

PubMed Central

Vasculogenesis, the assembly of the first vascular network, is an intriguing developmental process that yields the first functional organ system of the embryo. In addition to being a fundamental part of embryonic development, vasculogenic processes also have medical importance. To explain the organizational principles behind vascular patterning, we must understand how morphogenesis of tissue level structures can be controlled through cell behavior patterns that, in turn, are determined by biochemical signal transduction processes. Mathematical analyses and computer simulations can help conceptualize how to bridge organizational levels and thus help in evaluating hypotheses regarding the formation of vascular networks. Here we discuss the ideas that have been proposed to explain the formation of the first vascular pattern: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and sprouting guided by cell-cell contacts.

Czirok, Andras; Little, Charles D.

2012-01-01

188

Tetrahedron Formation Control  

NASA Technical Reports Server (NTRS)

This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include (1) targeting to a fixed tetrahedron location and orientation, and (2) rotating and translating the tetrahedron. The number of impulsive maneuvers can also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the NASA Goddard Magnetospheric Multi-Scale (MMS) mission to compute preliminary formation control fuel requirements.

Petruzzo, Charles; Guzman, Jose

2004-01-01

189

Cosmological structure formation  

NASA Technical Reports Server (NTRS)

A summary of the current forefront problem of physical cosmology, the formation of structures (galaxies, clusters, great walls, etc.) in the universe is presented. Solutions require two key ingredients: (1) matter; and (2) seeds. Regarding the matter, it now seems clear that both baryonic and non-baryonic matter are required. Whether the non-baryonic matter is hot or cold depends on the choice of seeds. Regarding the seeds, both density fluctuations and topological defects are discussed. The combination of isotropy of the microwave background and the recent observations indicating more power on large scales have severly constrained, if not eliminated, Gaussian fluctuations with equal power on all scales, regardless of the eventual resolution of both the matter and seed questions. It is important to note that all current structure formation ideas require new physics beyond SU(3) x SU(2) x U(1).

Schramm, David N.

1991-01-01

190

Formation of bacterial nanocells  

NASA Astrophysics Data System (ADS)

Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

Vainshtein, Mikhail; Kudryashova, Ekaterina; Suzina, Natalia; Ariskina, Elena; Voronkov, Vadim

1998-07-01

191

Cave Formation: Biogeochemical Cycles  

NSDL National Science Digital Library

This video explores the role of biogeochemical cycles in the formation of caves. It discusses a radical new theory that identifies sulfuric acid as a cave-forming agent. The video, adapted from a NOVA broadcast, identifies the source of the sulfuric acid, which, unlike carbonic acid, the typical cave-forming agent, does not readily form in nature. The segment is 5 minutes and forty seconds in length.

2011-07-28

192

Drumlin Formation Library Work  

NSDL National Science Digital Library

Students will individually produce a written introduction for a paper about the presence of drumlins on Mars - this introduction describes different models for drumlin formation on earth. To prepare for this assignment, students work in groups to do library research to find and read articles. The groups summarize their findings for each other. Each student then writes an introduction incorporating material from all the groups. Designed for a geomorphology course Uses geomorphology to solve problems in other fields

Anders, Alison M.

193

Nicotine and amyloid formation  

Microsoft Academic Search

The major protein constituents of amyloid deposits in Alzheimer’s disease (AD) are the 40-residue ?-amyloid (A?) (1–40) peptide and the 42-residue A?(1–42) peptide. The A?(1–42) is more pathogenic and produced in greater quantities in familial forms of AD. A major goal of research is to uncover a suitable inhibitor that either slows down or inhibits A? formation (?-amyloidosis). During ?-amyloidosis,

Hong Zeng; Yongbo Zhang; Li-Jun Peng; Haiyan Shao; Nanda K. Menon; Jing Yang; Arthur R. Salomon; Robert P. Freidland; Michael G. Zagorski

2001-01-01

194

Cave Formation: Biogeochemical Cycles  

NSDL National Science Digital Library

This video explores the role of biogeochemical cycles in the formation of caves. It discusses a radical new theory that identifies sulfuric acid as a cave-forming agent. The video, adapted from a NOVA broadcast, identifies the source of the sulfuric acid, which, unlike carbonic acid, the typical cave-forming agent, does not readily form in nature. The segment is 5 minutes and forty seconds in length.

195

Sedimentology and lithofacies of the Eocene Skookumchuk Formation in the Centralia coal mine, southwest Washington  

SciTech Connect

The late middle to late Eocene Skookumchuck Formation is well exposed in highwalls of the Centralia mine, southwest Washington. Three coal zones and intervening sandstone-rich successions occur in a 220-m-thick interval that extends from below the Smith to above the Tono No. 1 coal beds. The Smith-Big Dirty, Lower-Upper Thompson, and Tono No.`s. 1-2 coal zones contain coal beds that range from 0.5 to 15 m thick. The coal beds are interbedded with coarsening-upward units of mudstone, siltstone, and sandstone that are burrowed, flaser-and lenticular-bedded, mud-draped in their lower part, and rippled, wavy bedded, and tabular crossbedded (with reactivation surfaces) in their upper part. These coarsening-upward units are commonly overlain erosionally by fining-upward beds of trough-crossbedded, rippled, burrowed, and rooted sandstones. Coal formed in low-lying peat mires above mean high tide levels. Two discrete facies occur in the sandstone-rich successions between the coal zones. The first facies consists of very fine to coarse grained sandstones that have sharply defined bases and tops and are heavily bioturbated, horizontally bedded, trough crossbedded, hummocky bedded, and rippled. The second facies of the sandstone-rich successions consists of sandstone, siltstone, and mudstone beds with common ripple lamination, lenticular and flaser bedding, trough crossbedding, biotrubation, bivalve fossils, and root marks. Upward thinning of coal beds is consistent with deposition during a major transgression. These coals formed in mires of the tidally influenced coastal plain in the Centralia mine area, in contrast to coals elsewhere in Washington that accumulated in mires of the fluvial- and distributary-channel-influenced coastal plain. The Northcraft volcanic center to the east probably deflected fluvial drainages of the coastal plain to the north and south.

Flores, R.M.; Johnson, S.Y. [Geological Survey, Denver, CO (United States)

1995-04-01

196

Terrestrial planet formation.  

PubMed

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

Righter, K; O'Brien, D P

2011-11-29

197

[Synapse formation and regeneration].  

PubMed

Synapse formation is probably the key process in neural development allowing signal transmission between nerve cells. As an interesting model of synapse maturation, we considered first the neuromuscular junction (NMJ), whose development is particularly dependent on intercellular interactions between the motor nerve and the skeletal muscle. Nerve and muscle have distinct roles in synaptic compartment differentiation. The initial steps of this differentiation and motor endplate formation require several postsynaptic molecular agents including agrin, the tyrosine kinase receptor MuSK and rapsyn. The agrin or motoneuron dependence of this process continues to be debated while the following steps of axonal growth and postsynaptic apparatus maintenance essentially depend on neuronal agrin and a neuron-specific signal dispersing ectopic AChR aggregate remainders, possibly mediated by acetylcholine itself. Neuregulin is essentially involved in Schwann's cell survival and guidance for axonal growth. In this paper, we will discuss the similarities between Central Nervous System (CNS) synaptic formation and Motor innervation. The limited ability of the CNS to create new synapses after nervous system injury will be then discussed with a final consideration of some new strategies elaborated to circumvent the limitations of lesion extension processes. PMID:19230939

d'Houtaud, S; Sztermer, E; Buffenoir, K; Giot, J-P; Wager, M; Bauche, S; Lapierre, F; Rigoard, P

2009-03-01

198

Flocks and Formations  

NASA Astrophysics Data System (ADS)

Given a large number (the "flock") of moving physical objects, we investigate physically reasonable mechanisms of influencing their orbits in such a way that they move along a prescribed course and in a prescribed and fixed configuration (or "in formation"). Each agent is programmed to see the position and velocity of a certain number of others. This flow of information from one agent to another defines a fixed directed (loopless) graph in which the agents are represented by the vertices. This graph is called the communication graph. To be able to fly in formation, an agent tries to match the mean position and velocity of his neighbors (his direct antecedents on the communication graph) to his own. This operation defines a (directed) Laplacian on the communication graph. A linear feedback is used to ensure stability of the coherent flight patterns. We analyze in detail how the connectedness of the communication graph affects the coherence of the stable flight patterns and give a characterization of these stable flight patterns. We do the same if in addition the flight of the flock is guided by one or more leaders. Finally we use this theory to develop some applications. Examples of these are: flight guided by external controls, flocks of flocks, and some results about flocks whose formation is always oriented along the line of flight (such as geese).

Veerman, J. J. P.; Lafferriere, G.; Caughman, J. S.; Williams, A.

2005-12-01

199

Tetrahedron Formation Control  

NASA Technical Reports Server (NTRS)

Spacecraft flying in tetrahedron formations are excellent instrument platforms for electromagnetic and plasma studies. A minimum of four spacecraft - to establish a volume - is required to study some of the key regions of a planetary magnetic field. The usefulness of the measurements recorded is strongly affected by the tetrahedron orbital evolution. This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include targeting to a fixed tetrahedron orientation, rotating and translating the tetrahedron and/or varying the initial and final times. The number of impulsive maneuvers citn also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the Magnetospheric Multiscale Mission (MMS) to compute preliminary formation control fuel requirements.

Guzman, Jose J.

2003-01-01

200

Ribbed moraine formation  

NASA Astrophysics Data System (ADS)

Ribbed (Rogen) moraines are conspicuous landforms found in interior parts of formerly glaciated areas. Two major theories for ribbed moraine formation have been suggested in recent years: (i) the shear and stack theory, which explains ribbed moraine formation by shearing and stacking of till slabs or englacially entrained material during compressive flow, followed by basal melt-out of transverse moraine ridges, and (ii) the fracturing theory, according to which ribbed moraines form by fracturing of frozen pre-existing till sheets, at the transition from cold- to warm-based conditions under deglaciating ice sheets. In this paper, we present new data on the distribution of ribbed moraines and their close association with areas of frozen-bed conditions under ice sheets. In addition, we show examples of ribbed moraine ridges that fit together like a jig-saw puzzle. These observations indicate that fracturing and extension of a pre-existing till sheet may be a predominant process in ribbed moraine formation. In summary, we conclude that all described characteristics of ribbed moraines are compatible with the fracturing theory, while the shear and stack theory is hampered by an inability to explain many conspicuous features in the distribution pattern and detailed morphology of ribbed moraines. One implication of the fracturing theory is that the distribution of ribbed moraines can be used to reconstruct the extent of areas that underwent a change from frozen-bed to thawed-bed conditions under former ice sheets.

Hättestrand, Clas; Kleman, Johan

201

Terrestrial planet formation  

PubMed Central

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (?106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Righter, K.; O'Brien, D. P.

2011-01-01

202

Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures  

Microsoft Academic Search

STD 11, RFC 822, defines a message representation protocol specifying considerable detail about US-ASCII message headers, and leaves the message content, or message body, as flat US-ASCII text. This set of documents, collectively called the Multipurpose Internet Mail Extensions, or MIME, redefines the format of messages to allow for (1) textual message bodies in character sets other than US-ASCII,

J. Klensin

1996-01-01

203

Model of kimberlite formation  

NASA Astrophysics Data System (ADS)

The critical goals in recognizing the nature of kimberlites are to find out: (1) the primary composition of melt of these rocks and (2) the principal processes of evolution of primary composition of kimberlites while ascending from mantle depth towards earth surface. Suppose, that the primary composition of kimberlite melt-fluid was in fact the composition of asthenosphere melt geochemically being close to alkaline-basalt (Hi-µ) saturated with high CO2. The genetic relation of kimberlites with basaltoids is indicated by a spatial and temporal affinity of their formation (Carlson et al, 2006; Lehmann et al, 2010; Tappe et al, 2012), similarity of the pattern of incompatible elements distribution, presence of megacryst minerals in alkaline basaltoids, Pyr-Alm garnet included, and finally, model calculation of parent melt composition for low-Cr megacryst minerals; it showed this composition to be typical for the alkaline basaltoid (Jones, 1980). At the asthenosphere level there was differentiation of basaltoid melt-fluid which was responsible for formation of its different parts with varying melt to fluid ratio and possibly varying content of alkalis (K2O). The outbreak of asthenosphere substance through lithosphere mantle proceeded by different scenarios: (a) With a noticeable dominance of fluid component kimberlites were formed by the capture and contamination of high-Mg, high-Cr rocks of lithosphere mantle that caused formation of high-Mg kimberlites. That corresponds to model of Russell (2012). (b) With a considerable proportion of melt phase depending on saturation in fluid there formed magnesium-ferriferous and ferriferous-titaniferous petrochemical types of kimberlites. There is no doubt that in formation of these kimberlite types the contamination of lithosphere material was the case, at the much lower level than in formation of high-Mg kimberlites. This model logically explains steady differences of petrochemistry of kimberlites making up clusters of different pipes, fields of pipes and even province. The model clarifies presence or absence of low-Cr, high-Ti megacryst association of minerals, with its crystallization proceeding in the melt phase of asthenosphere source of kimberlites. The role of hybridism in kimberlite emplacement is vivid in considering the features of composition of breccias and massive kimberlites composing pipe and dyke bodies of Kuoiksky field, in particular Obnazhennaya pipe. The former compared to massive varieties the kimberlites show much higher contents of SiO2, MgO and much lower CaO and CO2. Massive varieties of kimberlites are more ferriferous and titaniferous. The onset of breccias formation should evidently be attributed to the time of passing kimberlite melt-fluid through the lithosphere mantle. It is triggered by the processes of disintegration and capture of its rocks. Considering the composition of mantle xenoliths captured by the ascending flow of kimberlite mantle-fluid, the onset of the hybridization process should be referred to the boundary of asthenosphere and mantle lithosphere. The most deep-seated xenoliths are deformed lherzolites, which experienced the direct metasomatic effect of asthenosphere melt (Nixon, Boyd, 1973; Burgess & Harte, 2004). The hybrid nature of kimberlites assumes both the mechanic capture of fragmented material of lithosphere mantle and its inevitable partial assimilation causing a significant change of primary melt composition.

Kostrovitsky, Sergey; Fiveyskaya, Lyudmila

2013-04-01

204

Ultrarelativistic black hole formation.  

PubMed

We study the head-on collision of fluid particles well within the kinetic energy dominated regime (? = 8 to 12) by numerically solving the Einstein-hydrodynamic equations. We find that the threshold for black hole formation is lower (by a factor of a few) than simple hoop conjecture estimates, and, moreover, near this threshold two distinct apparent horizons first form postcollision and then merge. We argue that this can be understood in terms of a gravitational focusing effect. The gravitational radiation reaches luminosities of 0.014 c(5)/G, carrying 16 ± 2% of the total energy. PMID:23521246

East, William E; Pretorius, Frans

2013-03-01

205

Adiabatic Halo Formation  

SciTech Connect

In a high intensity circular accelerator the synchrotron dynamics introduces a slow modulation in the betatronic tune due to the space-charge tune depression. When the transverse motion is non-linear due to the presence of multipolar effects, resonance islands move in the phase space and change their amplitude. This effect introduces the trapping and detrapping phenomenon and a slow diffusion in the phase space. We apply the neo-adiabatic theory to describe this diffusion mechanism that can contribute to halo formation.

Bazzani, A.; Turchetti, G.; Benedetti, C.; Rambaldi, S.; Servizi, G. [Physics Department University of Bologna, INFN Bologna, via Irnerio 46 40126 Bologna Italy (Italy)

2005-06-08

206

Interstellar chemistry: polycyanoacetylene formation  

SciTech Connect

Two opposing views are given for the formation of interstellar polycyanoacetylenes. One theory states that the carbon chains are formed by ion-molecule reactions in the gas phase. The opposing theory is that the polycyanoacetylenes are produced by fragmentation of polymerized cyanoacetylenes formed on grains. Each author states his reasons why he believes in his theory over the opposing theory. However, both authors agree that cyanopolyacetylenes are produced in nature in the absence of ion-molecule chemistry, i.e., the star IRC +10216. (SC)

Anders, E. (Univ. of Chicago, IL); Hayatsu, R.

1981-11-06

207

Modeling river delta formation  

PubMed Central

A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi River.

Seybold, Hansjorg; Andrade, Jose S.; Herrmann, Hans J.

2007-01-01

208

Particle Formation in Dextran Solutions.  

National Technical Information Service (NTIS)

The study indicated that temperature variation and the isolation of droplets of solution predispose to particle formation in bottled dextran solutions. Particle formation induced by temperature variation during short storage periods can be prevented by si...

R. A. Ewald, A. A. Young, W. H. Crosby

1964-01-01

209

Fuel spill reports-Format  

NSF Publications Database

Title : Fuel spill reports-Format Type : Antarctic EAM NSF Org: OD / OPP Date : February 05, 1991 ... Action Memorandum (Threshold for Fuel Spill Reports/Format for Fuel Spill Reports) To: Files (S.7 - ...

210

Automation of Formation Flight Control.  

National Technical Information Service (NTIS)

The research contained in this thesis explores the concepts of Automated Formation Flight Control documented in three previous AFIT theses. The generic formation analyzed consists of a Leader and Wingman, with the Wingman referencing its maneuvers off of ...

V. P. Reyna

1994-01-01

211

Method for measuring pollutant formation  

NASA Technical Reports Server (NTRS)

Diagnostic methods for determining an instantaneous rate of pollutant formation in a combustion system are based on measurement of chemiluminescence intensity generated simultaneously with the formation of the pollutant. The chemiluminescent signal is generated by an analog reaction which occurs in parallel with a key step in the formation of a specific pollutant of interest. The connection between the analog reaction and the pollution reaction is such that the chemiluminescent signal indicates the local, instantaneous formation rate of the pollutant of interest.

Annen, Kurt (Inventor); Stickler, David B. (Inventor)

2001-01-01

212

Formative Assessment: Simply, No Additives  

ERIC Educational Resources Information Center

Among the types of assessment the closest to daily reading instruction is formative assessment. In contrast to summative assessment, which occurs after instruction, formative assessment involves forming judgments frequently in the flow of instruction. Key features of formative assessment include identifying gaps between where students are and…

Roskos, Kathleen; Neuman, Susan B.

2012-01-01

213

Bone formation by cancer metastases  

Microsoft Academic Search

The formation of heterotopic bone tissue in malignant tumors or in their metastases is extremely rare. In a 60 years old male patient with bronchogenic carcinoma (adenocarcinoma) extensive bone formation was observed within multiple metastases in the skeletal muscles. On the basis of the microscopic findings, the mechanism of bone formation by malignant tumors is discussed. Obviously, proliferation of local

U. Bettendorf; W. Remmele; H. Laaff

1976-01-01

214

Formative assessment: a critical review  

Microsoft Academic Search

This paper covers six interrelated issues in formative assessment (aka, ‘assessment for learning’). The issues concern the definition of formative assessment, the claims commonly made for its effectiveness, the limited attention given to domain considerations in its conceptualisation, the under?representation of measurement principles in that conceptualisation, the teacher?support demands formative assessment entails, and the impact of the larger educational system.

Randy Elliot Bennett

2011-01-01

215

Star formation and molecular clouds  

NASA Technical Reports Server (NTRS)

Several differnt stages can be discerned within the star formation process. Star formation can be considered to start when a molecular cloud fragments into many clumps. Many different physical processes are likely to play an important role in star formation, including self-gravity, magnetic fields, rotation, winds, and radiation transport. The current knowledge on some of these processes are reviewed.

Tielens, Alexander G. G. M.

1988-01-01

216

Biofilm formation by haloarchaea.  

PubMed

A fluorescence-based live-cell adhesion assay was used to examine biofilm formation by 20 different haloarchaea, including species of Halobacterium, Haloferax and Halorubrum, as well as novel natural isolates from an Antarctic salt lake. Thirteen of the 20 tested strains significantly adhered (P-value ?< 0.05) to a plastic surface. Examination of adherent cell layers on glass surfaces by differential interference contrast, fluorescence and confocal microscopy showed two types of biofilm structures. Carpet-like, multi-layered biofilms containing micro- and macrocolonies (up to 50 ?m in height) were formed by strains of Halobacterium salinarum and the Antarctic isolate t-ADL strain DL24. The second type of biofilm, characterized by large aggregates of cells adhering to surfaces, was formed by Haloferax volcanii DSM 3757T and Halorubrum lacusprofundi DL28. Staining of the biofilms formed by the strongly adhesive haloarchaeal strains revealed the presence of extracellular polymers, such as eDNA and glycoconjugates, substances previously shown to stabilize bacterial biofilms. For Hbt. salinarum DSM 3754T and Hfx. volcanii DSM 3757T , cells adhered within 1 day of culture and remained viable for at least 2 months in mature biofilms. Adherent cells of Hbt. salinarum DSM 3754T showed several types of cellular appendages that could be involved in the initial attachment. Our results show that biofilm formation occurs in a surprisingly wide variety of haloarchaeal species. PMID:23057712

Fröls, Sabrina; Dyall-Smith, Mike; Pfeifer, Felicitas

2012-12-01

217

Collagen fibril formation.  

PubMed Central

Collagen is most abundant in animal tissues as very long fibrils with a characteristic axial periodic structure. The fibrils provide the major biomechanical scaffold for cell attachment and anchorage of macromolecules, allowing the shape and form of tissues to be defined and maintained. How the fibrils are formed from their monomeric precursors is the primary concern of this review. Collagen fibril formation is basically a self-assembly process (i.e. one which is to a large extent determined by the intrinsic properties of the collagen molecules themselves) but it is also sensitive to cell-mediated regulation, particularly in young or healing tissues. Recent attention has been focused on "early fibrils' or "fibril segments' of approximately 10 microns in length which appear to be intermediates in the formation of mature fibrils that can grow to be hundreds of micrometers in length. Data from several laboratories indicate that these early fibrils can be unipolar (with all molecules pointing in the same direction) or bipolar (in which the orientation of collagen molecules reverses at a single location along the fibril). The occurrence of such early fibrils has major implications for tissue morphogenesis and repair. In this article we review the current understanding of the origin of unipolar and bipolar fibrils, and how mature fibrils are assembled from early fibrils. We include preliminary evidence from invertebrates which suggests that the principles for bipolar fibril assembly were established at least 500 million years ago.

Kadler, K E; Holmes, D F; Trotter, J A; Chapman, J A

1996-01-01

218

Deep water formation  

NASA Technical Reports Server (NTRS)

Some simple arguments on plumes of dense water and filling boxes were given. What determines the time for a large-scale environment to be modified by the injection of dense water at its edge is the mass flux, not the buoyancy flux. However, it is the denser buoyancy flux, when there are several competing plumes (e.g., the Mediterranean outflow versus the Denmark Strait outflow) that determines which plume will provide the bottom water for that ocean basin. It was noted that the obvious laboratory experiment (rotate a pie-shaped annulus, and heat/cool it on the surface) had never been performed. Thus, to some extent our belief that deep convection is somehow automatic at high latitudes to close off some ill-defined meridional circulation has never been tested. A summary of deep convection was given. The two fundamental formation mechanisms were shown. Of the two, it is open-ocean convection which forms the water which supplies the Denmark Strait overflow -- in all likelihood, as formation in the Greenland Sea remains stubbornly unobserved. But it is the slope convection which finally creates North Atlantic deep water, following the Denmark Strait overspill.

Killworth, P. D.

1984-01-01

219

Granular Crater Formation  

NASA Astrophysics Data System (ADS)

This project characterizes crater formation in a granular material by a jet of gas impinging on a granular material, such as a retro-rocket landing on the moon. We have constructed a 2D model of a planetary surface, which consists of a thin, clear box partially filled with granular materials (sand, lunar and Mars simulants...). A metal pipe connected to a tank of nitrogen gas via a solenoid valve is inserted into the top of the box to model the rocket. The results are recorded using high-speed video. We process these images and videos in order to test existing models and develop new ones for describing crater formation. A similar set-up has been used by Metzger et al.footnotetextP. T. Metzger et al. Journal of Aerospace Engineering (2009) We find that the long-time shape of the crater is consistent with a predicted catenary shape (Brandenburg). The depth and width of the crater both evolve logarithmically in time, suggesting an analogy to a description in terms of an activated process: dD/dt = A (-aD) (D is the crater depth, a and A constants). This model provides a useful context to understand the role of the jet speed, as characterized by the pressure used to drive the flow. The box width also plays an important role in setting the width of the crater.

Clark, Abe; Behringer, Robert; Brandenburg, John

2009-11-01

220

Bubble formation in microgravity  

NASA Technical Reports Server (NTRS)

Two KC-135 flight campaigns have been conducted to date which are specifically dedicated to study bubble formation in microgravity. The first flight was conducted during March 14-18, 1994, and the other during June 20-24, 1994. The results from the June 1994 flight have not been analyzed yet, while the results from the March flight have been partially analyzed. In the first flight three different experiments were performed, one with the specific aim at determining whether or not cavitation can take place during any of the fluid handling procedures adopted in the shuttle bioprocessing experiments. The other experiments were concerned with duplicating some of the procedures that resulted in bubble formation, namely the NCS filling procedure and the needle scratch of a solid surface. The results from this set of experiments suggest that cavitation did not take place during any of the fluid handling procedures. The results clearly indicate that almost all were generated as a result of the breakup of the gas/liquid interface. This was convincingly demonstrated in the scratch tests as well as in the liquid fill tests.

Antar, Basil N.

1994-01-01

221

LISA satellite formation control  

NASA Astrophysics Data System (ADS)

The joint ESA-NASA Laser Interferometer Space Antenna (LISA) mission consists of a triangular formation of three satellites aiming at detecting gravitational waves. In linear approximation the LISA satellites describe a circle around a reference point, maintaining a fixed position with respect to each other. The reference point, the center of the triangle, orbits the Sun in a circular orbit, trailing the Earth at twenty degrees. In reality the distance between the satellites will vary by about one to two percent and the angle between the arms of the antenna will vary by about 0.5° over the course of one year for the nominal LISA satellite configuration. For measurement accuracy it is desirable that the pointing offset of the telescopes be kept small. This makes it necessary to actuate the telescopes or to control the formation. It was assumed that the LISA satellites are equipped with six ?N engines that would allow to keep the two cubical proof masses within each satellite in almost perfect free fall. It was found that control forces up to about 700 ?N are required for maintaining the absolute triangular LISA formation, leading to unacceptable excursions of the proof masses from free fall. However, these forces compensate predominantly very low frequency variations of the arm lengths and angles of the triangle, which are then to be compensated by the telescope actuators. The variations are outside the aimed LISA measurement bandwidth (10 -4-0.1 Hz). In addition, the effect of thruster noise, orbit determination errors and orbit injection errors was examined. The effect of these error sources on the arm lengths and orientation angles between the LISA satellites was assessed both in open loop and in closed loop, where the closed loop was based on a proportional-derivative (PD) controller. It was found that orbit determination errors of the order of a few km in position and a few mm/s in velocity lead to negligible closed loop control forces. In addition, orbit injection errors of the order of 10 km in position and 1 cm/s in velocity could be eliminated after a few days when thrusting at levels of 200-500 ?N. Even for a high estimated level of thruster noise below 10 -4 Hz (equivalent to about 2 ?N random thrusts once an hour), the closed loop controller effectively reduced the effect on the angles of the triangle to below 30 nrad.

Bik, J. J. C. M.; Visser, P. N. A. M.; Jennrich, O.

222

STILTS: Starlink Tables Infrastructure Library Tool Set  

NASA Astrophysics Data System (ADS)

The STIL Tool Set is a set of command-line tools based on STIL, the Starlink Tables Infrastructure Library. It deals with the processing of tabular data; the package has been designed for, but is not restricted to, astronomical tables such as object catalogues. Some of the tools are generic and can work with multiple formats (including FITS, VOTable, CSV, SQL and ASCII), and others are specific to the VOTable format. In some ways, STILTS forms the command-line counterpart of the GUI table analysis tool TOPCAT. The package is robust, fully documented, and designed for efficiency, especially with very large datasets. Facilities offered include: format conversion crossmatching plotting column calculation and rearrangement row selections data and metadata manipulation and display sorting statistical calculations histogram calculation data validation VO service access A powerful and extensible expression language is used for specifying data calculations. These facilities can be put together in very flexible and efficient ways. For tasks in which the data can be streamed, the size of table STILTS can process is effectively unlimited. For other tasks, million-row tables usually do not present a problem. STILTS is written in pure Java (J2SE1.5 or later), and can be run from the command line or from Jython, or embedded into java applications. It is released under the GPL.

Taylor, Mark

2011-05-01

223

Ferricyanide-humate formation  

NASA Astrophysics Data System (ADS)

We studied the complexation of ferricyanide ion by humic substances (HS) at acidic, neutral and basic pH by means of cyclic voltammetry (CV) and UV-visible spectroscopy. The CV measurements carried out at pH 3.5 and 7 showed that the first addition of HS (0.05 mg mL^{-1} of organic carbon) to ferricyanide solution caused a shift of both cathodic and anodic peak potentials together with a depression of the corresponding peak currents. After successive addition of HS further depression of peak currents were observed. Experiments perfonned at pH 12.5 showed no changes in peak current and peak potential after addition of HS. These results suggested the formation of ferricyanide-HS complexes at pH 3.5 and 7 and were confirmed by UV-Vis spectra recorded in concomitance to voltammetric measurements.

Leita, L.; Petruzzelli, G.; Fornasier, F.

2003-05-01

224

Glass formation in microgravity  

NASA Technical Reports Server (NTRS)

An account is given of containerless glass-forming experiments conducted aboard the Space Shuttle in 1985, using a single-axis acoustic levitator furnace apparatus. An attempt was made to obtain quantitative evidence for the suppression of heterogeneous nucleation/crystallization in containerless melts under microgravity conditions, as well as to study melt homogenization in the absence of gravity-driven convection and assess the feasibility of laser fusion target glass microsphere preparation with a microgravity apparatus of the present type. A ternary calcia-gallia-silica glass thus obtained indicated a 2-3-fold increase in glass-formation tendency for this material composition in microgravity, by comparison with 1g.

Ray, C. S.; Day, D. E.

1987-01-01

225

Pattern Formation in Materials  

NASA Astrophysics Data System (ADS)

Pattern formation is ubiquitous in nature, from sand ripples formed by wind to the development of a complex biological organism with different organs and a central nervous system. In the realm of materials, patterns are formed invariably when matter is transformed between different solid, liquid or gaseous states far from thermodynamic equilibrium. Material failure is itself mediated by the propagation of cracks that form intricate patterns. Understanding how patterns form and evolve is key to design materials with desired properties and to optimize their performance and safety. This talk will discuss recent progress made to understand three distinct class of patterns including the highly branched snow-flake-like dendritic patterns formed during the solidification process, polycrystalline patterns shaped by grain boundaries, and crack patterns.

Karma, Alain

2011-04-01

226

Dust Formation in Macronovae  

NASA Astrophysics Data System (ADS)

We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

Takami, Hajime; Nozawa, Takaya; Ioka, Kunihito

2014-07-01

227

Chorionic Villi Formation  

NSDL National Science Digital Library

This FlashTM animation depicts morphogenesis of chorionic villi. It begins by displaying a cross section through the three layers of the chorion, with a maternal sinusoid expanding through the syncyciotrophoblast. Clicking causes the lesson to progress through a stepwise display of the formation of stem, terminal, primary, secondary and tertiary villi, with the intervillous space and outer trophoblastic shell. The lesson ends with an explanation of how the chorionic villi of the placenta mediate diffusion between the fetal and maternal circulatory systems. A back button allows users to jump to previous scenes, a rate button allows them to toggle between fast and slow modes, and a text button allows them to toggle explanatory text on and off.

PhD Jack D Thatcher (West Virginia School of Osteopathic Medicine Structural Biology)

2010-11-29

228

Pine Island Iceberg Formation  

NSDL National Science Digital Library

This animation is a sequence showing the formation of the Pine Island iceberg and the glacial seaward flow upstream from the crack. It is a series of MISR images from the Terra satellite on top of the continental Radarsat view of Antarctica. The Pine Island Glacier is the largest discharger of ice in Antarctica and the continents fastest moving glacier. Even so, when a large crack formed across the glacier in mid 2000, it was surprising how fast the crack expanded, 15 meters per day, and how soon the resulting iceberg broke off, mid-November, 2001. This iceberg, called B-21, is 42 kilometers by 17 kilometers and contains seven years of glacier outflow released to the sea in a single event.

Perkins, Lori; Bindschadler, Bob; Diner, Dave

2002-01-10

229

Dityrosine formation in calmodulin  

SciTech Connect

Ultraviolet (280-nm) irradiation of bovine brain calmodulin results in calcium-dependent changes in its fluorescence emission spectrum. These consist of a decline in the intrinsic tyrosine fluorescence of the protein and the appearance of a new emission maximum at 400 nm. Chromatography of irradiated calmodulin, using Ultrogel AcA 54 and phenyl-agarose columns, yields several distinctive fractions. One of these, representing 2.8% of the total recovered protein and 53% of the total fluorescence emission at 400 nm, was selected for detailed characterization. Analyses performed on acid hydrolysates reveal the presence of dityrosine, a derivative of tyrosine known for its fluorescence near 400 nm, at the level of 0.59-0.89 mol per 16,700 g of protein. Sodium dodecyl sulfate gel electrophoresis experiments demonstrate two components of apparent molecular weights 14,000 (80%) and 16,000 (20%). Observations on the effects of UV irradiation on the thrombic fragments of calmodulin and on related calcium binding proteins (rabbit skeletal muscle troponin C, bovine cardiac troponin C, and parvalbumin) support the interpretation that dityrosine formation in calmodulin results from the intramolecular cross-linking of Tyr-99 and Tyr-138. The dityrosine-containing photoproduct of calmodulin is unable to stimulate the p-nitrophenyl phosphatase activity of calcineurin under standard assay conditions. Smooth muscle myosin light chain kinase binds the derivative about 280-fold less effectively than it binds native calmodulin. Of several metal ions tested, only Cd/sup 2 +/ approaches Ca/sup 2 +/ in its ability to promote the appearance of the 400-nm emission band during UV irradiation of calmodulin. Mn/sup 2 +/ and Cu/sup 2 +/ appear to inhibit dityrosine formation.

Malencik, D.A.; Anderson, S.R.

1987-02-10

230

A Generic Data Exchange Scheme Between FITS Format and C Structures  

NASA Astrophysics Data System (ADS)

A flexible and efficient scheme allowing arbitrary FITS Binary and ASCII Tables to be converted to arbitrary C structures at run-time is presented. This scheme has been successfully implemented and used with \\htmllink{Shiva}{http://www- sdss.fnal.gov:8000/shiva/doc/www/shiva.home.html} (Survey Human Interface and Visualization Environment), a package developed by Fermilab for the analysis of Sloan Digital Sky Survey data.

Peng, W.; Nicinski, T.

231

BOREAS TGB-4 NSA-BVP Tower Flux and Meteorological Data  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB-4) team measured the exchange of heat, water, and CO2 between a boreal forest beaver pond and the atmosphere in the Northern Study Area (NSA) for the ice-free period of BOREAS. The data cover the period of 28-May to 18-Sep-1994. The data are available in tabular ASCII files.

Roulet, Nigel T.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Conrad, Sara K. (Editor)

2000-01-01

232

BOREAS TF-2 SSA-OA Tethersonde Meteorological and Ozone Data  

NASA Technical Reports Server (NTRS)

The BOReal Ecosystem-Atmosphere Study Tower Flux-2 (BOREAS TF-2) team collected meteorological and ozone measurements from instruments mounted below a tethered balloon. These data were collected at the Southern Study Area Old Aspen (SSA-OA) site to extend meteorological and ozone measurements made from the flux tower to heights of 300 m. The tethersonde operated during the fall of 1993 and the spring, summer, and fall of 1994. The data are available in tabular ASCII files.

Arnold, A. James; Mickle, Robert E.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

233

BOREAS TF-4 CO2 and CH4 Chamber Flux Data from the SSA  

NASA Technical Reports Server (NTRS)

The BOREAS TF-4 team measured fluxes of CO2 and CH4 across the soil-air interface in four ages of jack pine forest at the BOREAS SSA during August 1993 to March 1995. Gross and net flux of CO2 and flux of CH4 between soil and air are presented for 24 chamber sites in mature jack pine forest, 20-year-old, 4-year-old, and clear cut areas. The data are stored in tabular ASCII files.

Anderson, Dean; Striegl, Robert; Wickland, Kimberly; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

2000-01-01

234

BOREAS RSS-11 Ground Network of Sunphotometer Measurements  

NASA Technical Reports Server (NTRS)

The BOREAS RSS-11 team operated a network of five automated (Cimel) and two hand-held (Miami) solar radiometers from 1994 to 1996 during the BOREAS field campaigns. The data provide aerosol optical depth measurements, size distribution, phase function, and column water vapor amounts over points in northern Saskatchewan and Manitoba, Canada. The data are useful for the correction of remotely sensed aircraft and satellite images. The data are provided in tabular ASCII files.

Markham, Brian L.; Hall, Forrest G. (Editor); Nickerson, Jaime (Editor); Schafer, Joel; Smith, David E. (Technical Monitor)

2000-01-01

235

BOREAS TF-1 SSA-OA Weekly Tower CH4 and N2O Flux  

NASA Technical Reports Server (NTRS)

The BOREAS TF-1 team collected various trace gas and energy flux data in its efforts to characterize the temporal energy and gas exchanges that occurred over the SSA-OA site. This data set contains methane (CH4) and nitrous oxide (N2O) fluxes that were measured at the BOREAS SSA-OA site. These fluxes were measured from 16-Apr to 16-Sep-1994. The data were averaged to weekly values and are available in tabular ASCII files.

Thurtell, George; Edwards, Grant; Simpson, George; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

236

BOREAS TGB-1 NSA SF6 Chamber Flux Data  

NASA Technical Reports Server (NTRS)

The BOREAS TGB-1 team made several chamber and tower measurements of trace gases at sites in the BOREAS NSA. This data set contains sulfur hexafluoride (SF6) dark chamber flux measurements at the NSA-OJP and NSA-YJP sites from 16-May through 13-Sep-1994. Gas samples were extracted approximately every 7 days from dark chambers and analyzed at the NSA lab facility. The data are provided in tabular ASCII files.

Crill, Patrick; Varner, Ruth K.; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

237

County-based estimates of nitrogen and phosphorus content of animal manure in the United States for 1982, 1987, and 1992  

USGS Publications Warehouse

names that correspond to the FIPS codes. 2. Tabular component - Nine tab-delimited ASCII lookup tables of animal counts and nutrient estimates organized by 5-digit state/county FIPS (Federal Information Processing Standards) code. Another table lists the county names that correspond to the FIPS codes. The use of trade names is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey.

Puckett, Larry; Hitt, Kerie; Alexander, Richard

1998-01-01

238

The roles of organic matter in the formation of uranium deposits in sedimentary rocks  

Microsoft Academic Search

Because reduced uranium species have a much smaller solubility than oxidized uranium species and because of the strong association of organic matter (a powerful reductant) with many uranium ores, reduction has long been considered to be the precipitation mechanism for many types of uranium deposits. Organic matter may also be involved in the alterations in and around tabular uranium deposits,

Charles S. Spirakis

1996-01-01

239

Gas formation. Formation temperatures of thermogenic and biogenic methane.  

PubMed

Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a "clumped isotope" technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models. PMID:24970083

Stolper, D A; Lawson, M; Davis, C L; Ferreira, A A; Santos Neto, E V; Ellis, G S; Lewan, M D; Martini, A M; Tang, Y; Schoell, M; Sessions, A L; Eiler, J M

2014-06-27

240

Star formation in elliptical galaxies  

NASA Astrophysics Data System (ADS)

In this paper we anticipate part of the results of a recent study by the Padova group to cast light on the formation and evolution of elliptical galaxies by means of N-body TSPH simulations including star formation, feed-back and chemical evolution. Particular attention is paid here to the case of dwarf spheroidals of the Local Group which, thanks to their proximity and modern ground-based and space instrumentation, can be resolved into single stars so that independent determinations of their age and star formation history can be derived. Dwarf galaxies are known to exhibit complicated histories of star formation ranging from a single very old episode to a series of bursts over most of the Hubble time. By understanding the physical process driving star formation in these objects, we might be able to infer the mechanism governing star formation in more massive elliptical galaxies.

Chiosi, Cesare

241

Gaining Insight into Star Formation: Resolved Star Formation Laws  

NASA Astrophysics Data System (ADS)

Until recently astronomers have used star formation laws to measure the star formation rate and star formation efficiency of galaxies only on global scales because of the poor resolution of available data. What I am now capable of producing is a spatially resolved star formation law that can provide direct insight into the physical processes that govern star formation and assess the short-term nature of bursts of star formation and the longer-term nature of larger-scale events that can dictate the global distribution of stars and the ultimate fate of a galaxy as a whole. I am using exquisite narrowband optical data from a variety of sources, including the Hubble Space Telescope, and Kitt Peak National Observatory, etc., in conjunction with infrared data from the Spitzer Infrared Nearby Galaxy Survey and the Spitzer Local Volume Legacy survey, neutral gas data from The HI Nearby Galaxy Survey, and molecular gas data from the Berkeley-Illinois-Maryland Association Survey of Nearby Galaxies, to provide star formation rates and star formation efficiencies on previously inaccessible small spatial scales across a suite of galaxies that represent a range of star formation environments and scales. My sample includes 18 spiral galaxies ranging from 2.1 to 15.1 Mpc in distance and offers a large range of morphological types (i.e. a large range of star formation environments). I am using these data to test different models of star formation modes under a variety of physical conditions and relate the variations I observe to the known local physical conditions and the associated star formation histories for each locale within each galaxy.This is the heart of the matter - that the nature and evolution of the local physical environment intimately influences how stars can form, how quickly and how massive those stars are allowed to form, and as a result how they shape the local conditions for subsequent star formation. It is this tracking of the stellar ecology that is vital for insight into the star formation process, but also to understand the conditions that can result in star and planet formation, or conversely what conditions prevent this. Such an analysis is only possible with the kind of datasets I am producing.

Liebst, Kelley; Scowen, Paul A.

2014-06-01

242

Bead lightning formation  

SciTech Connect

Formation of beaded structures in triggered lightning discharges is considered in the framework of both magnetohydrodynamic (MHD) and hydrodynamic instabilities. It is shown that the space periodicity of the structures can be explained in terms of the kink and sausage type instabilities in a cylindrical discharge with anomalous viscosity. In particular, the fast growth rate of the hydrodynamic Rayleigh-Taylor instability, which is driven by the backflow of air into the channel of the decaying return stroke, dominates the initial evolution of perturbations during the decay of the return current. This instability is responsible for a significant enhancement of the anomalous viscosity above the classical level. Eventually, the damping introduced at the current channel edge by the high level of anomalous viscous stresses defines the final length scale of bead lightning. Later, during the continuing current stage of the lightning flash, the MHD pinch instability persists, although with a much smaller growth rate that can be enhanced in a M-component event. The combined effect of these instabilities may explain various aspects of bead lightning.

Ludwig, G.O.; Saba, M.M.F. [Associated Plasma Laboratory, National Space Research Institute, 12227-010, Sao Jose dos Campos, SP (Brazil); Division of Space Geophysics, National Space Research Institute, 12227-010, Sao Jose dos Campos, SP (Brazil)

2005-09-15

243

ARTIST tape output formats  

NASA Astrophysics Data System (ADS)

The format of the ARTIST data and raw data records written to magnetic tape are described. The contents of each record type are fully explained making possible an unpacking of the data for subsequent analysis. A new generation of modern ionosondes is now being deployed world wide. These are the University of Lowell Center for Atmospheric Research (ULCAR) Digisonde 256 and AN/FMQ-12 DISS systems. The Digisonde 256 network will provide a consistent data set of ionospheric parameters that are automatically scaled in real time. The automated stations output the standard ionospheric parameters, the h'N(f) traces with amplitudes and Doppler frequencies, and the electron density profiles. There are currently 32 systems in operation or are close to being installed. The global station distribution is very uneven, the majority of sites lying in the northern hemisphere, and there are no equatorial stations. Nevertheless this network provides an extensive data base of ionospheric parameters in digital form, making it easy to process and analyze the data in terms of average diurnal variations, storms, and irregularities. This data base will be invaluable for the testing of global ionosphere models.

Tang, Jane; Dozois, Claude G.; Gamache, Robert R.

1990-07-01

244

Formation of "bound  

NASA Astrophysics Data System (ADS)

During degradation of organic pollutants in soil, metabolites, microbial biomass, CO2and "bound" residues ("non-extractable" residues in soil organic matter) are formed. Enhanced transformation of these contaminants into "bound" residues has been proposed as an alternative remediation method for polluted soils. However, this kind of residues may pose a potential risk for the environment due to their chemical structure and possible remobilization under different conditions. Therefore particular attention is given actually to "bound" residues. Part of these non-extractable residues may be "biogenic," because microorganisms use the carbon from the pollutant to form their biomass components (fatty acids, amino acids, amino sugars), which subsequently may be incorporated into soil organic matter. Furthermore, the CO2 originating from mineralization of xenobiotics, can be re-assimilated by microorganisms and also incorporated into "biogenic residue". The hazard posed by "bound" residues may be overestimated because they are "biogenic" (contain microbial fatty acids and amino acids). The knowledge about the pathways of "biogenic residue" formation is necessary for a proper assessment of the fate of tested pollutants and their turnover in the soil environment. Moreover, these data are needed to establish the realistic degradation rates of the contaminants in soil. The main objectives of this study are: to quantify the extent of "biogenic residue" (fatty acids, amino acids, amino sugars) formation during the degradation of a model pollutant (2,4-dichlorophenoxyacetic acid = 2,4-D) and during CO2 assimilation by microorganisms and to evaluate which components are mainly incorporated into "bound" residues. To investigate the extent of "biogenic residue" formation in soil during the degradation of 2,4-D, experiments with either 14C-U-ring and 13C6-2,4-D or carboxyl-14C 2,4-D were performed. The incubation experiments were performed according to OECD test guideline 307, in the dark, at constant temp 20Ë? C (+/-2Ë? C) and with intermittent aeration. During incubation, the mineralization was quantified and soil samples were analyzed for the presence of both "biogenic residues" and remaining 2,4-D. Mineralization of 2,4-D in both experiments was very high. However, the 14CO2 evolution was higher from carboxyl-14C 2,4-D than from 14C-ring 2,4-D. After 7 days of incubation, 30% of initial amount of 14C in soil contaminated with 14C-ring 2,4-D was mineralized, whereas 40% of total radioactivity was evolved as CO2after 4 days from soil incubated with 14C-carboxyl 2,4-D. The amount of extractable 2,4-D residues was very low in both experiments (14C-ring 2,4-D: 2% and 14C-carboxyl 2,4-D: 1%). The soil incubated with 14C-ring 2,4-D contained 60% of "non-extractable" residues of 2,4-D after 7 days, while the amount of these residues in soil contaminated with 14C-carboxyl 2,4-D reached 50% of the initial radioactivity in the tested system 4 days after application. More "biogenic residues" were formed in soil spiked with 14C-U-ring 2,4-D (10%) than in soil with carboxyl 14C 2,4-D (7%). Both 2,4-D and CO2-derived C were incorporated mainly into microbial amino acids (9.5% at day 7 and 7.0% at day 4, respectively). After 7 days of incubation, 0.5% of initial applied radioactivity in system was found in microbial lipids in the soil contaminated with 14C-ring 2,4-D. Only 0.1% of the total radioactivity was incorporated into lipids in soil treated with 14C-carboxyl 2,4-D on day 4 after application. Thin Layer Chromatography identified the microbial lipids containing the radioactivity as phosphatidylethanolamine, a phospholipid typical for microorganisms. The amount of microbial lipids (which corresponds to phospholipids) in both cases decreased with time; this can be explained by the death of the microbial biomass. To the best of our knowledge, this is the first report on the formation of &qu

Nowak, K.; Kästner, M.; Miltner, A.

2009-04-01

245

Large Format Radiographic Imaging  

SciTech Connect

Radiographic imaging continues to be a key diagnostic in many areas at Los Alamos National Laboratory (LANL). Radiographic recording systems have taken on many form, from high repetition-rate, gated systems to film recording and storage phosphors. Some systems are designed for synchronization to an accelerator while others may be single shot or may record a frame sequence in a dynamic radiography experiment. While film recording remains a reliable standby in the radiographic community, there is growing interest in investigating electronic recording for many applications. The advantages of real time access to remote data acquisition are highly attractive. Cooled CCD camera systems are capable of providing greater sensitivity with improved signal-to-noise ratio. This paper begins with a review of performance characteristics of the Bechtel Nevada large format imaging system, a gated system capable of viewing scintillators up to 300 mm in diameter. We then examine configuration alternatives in lens coupled and fiber optically coupled electro-optical recording systems. Areas of investigation include tradeoffs between fiber optic and lens coupling, methods of image magnification, and spectral matching from scintillator to CCD camera. Key performance features discussed include field of view, resolution, sensitivity, dynamic range, and system noise characteristics.

J. S. Rohrer; Lacey Stewart; M. D. Wilke; N. S. King; S. A Baker; Wilfred Lewis

1999-08-01

246

Galactic and extragalactic star formation  

SciTech Connect

This book present new technology that allows the linking of the physics of local star forming regions to the global star forming properties of galaxies. Galactic star formation and examination of the processes of formation of nearby stars are addressed. Focus is on bipolar outflows and circumstellar disks. Larger scale phenomena in molecular clouds are then discussed, followed by reviews of star formation across the Milky Way.

Pudritz, R.E. (Minnesota Univ., Minneapolis, MN (USA). Heat Transfer Lab.); Fich, M. (Waterloo Univ., ON (Canada))

1988-01-01

247

Energy saving in flight formation.  

PubMed

Many species of large bird fly together in formation, perhaps because flight power demands and energy expenditure can be reduced when the birds fly at an optimal spacing, or because orientation is improved by communication within groups. We have measured heart rates as an estimate of energy expenditure in imprinted great white pelicans (Pelecanus onocrotalus) trained to fly in 'V' formation, and show that these birds save a significant amount of energy by flying in formation. This advantage is probably a principal reason for the evolution of flight formation in large birds that migrate in groups. PMID:11607019

Weimerskirch, H; Martin, J; Clerquin, Y; Alexandre, P; Jiraskova, S

2001-10-18

248

"Translating" between survey answer formats?  

PubMed Central

Survey research remains the most popular source of market knowledge, yet researchers have not yet established one consistent technique for measuring responses. Some market research companies offer respondents two answer options; others five or seven. Some answer formats use middle points on the answer scales, others do not. Some formats verbalize all answer options, some only the endpoints. The wide variety of answer formats that market research companies and academic researchers use makes comparing results across studies virtually impossible. This study offers guidance for market researchers by presenting empirical translations for the answer formats they most commonly use, thus enabling easier comparisons of results.

Dolnicar, Sara; Grun, Bettina

2013-01-01

249

Formative Assessment Probes: Is It a Rock? Continuous Formative Assessment  

ERIC Educational Resources Information Center

A lesson plan is provided for a formative assessment probe entitled "Is It a Rock?" This probe is designed for teaching elementary school students about rocks through the use of a formative assessment classroom technique (FACT) known as the group Frayer Model. FACT activates students' thinking about a concept and can be used to…

Keeley, Page

2013-01-01

250

Medusae Fossae Formation  

NASA Technical Reports Server (NTRS)

An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. In the Mars Orbiter Camera (MOC) image shown on the right, the crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

The MOC image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The context image (left; the best Viking view of the area; VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

1998-01-01

251

Gravity Data for the State of Washington.  

National Technical Information Service (NTIS)

Washington state gravity data in ASCII format are contained on a 9-track magnetic tape described in this report. The tape was written at a density of 1600 BPI and contains one file of 24,526 records of 80 ASCII characters each. The data consists of statio...

C. Finn

1985-01-01

252

Feasible formations of multi-agent systems  

Microsoft Academic Search

Formations of multi-agent systems, such as satellites and aircraft, require that individual agents satisfy their kinematic equations while constantly maintaining inter-agent constraints. In this paper, we develop a systematic framework for studying formations of multiagent systems. In particular, we consider undirected formations for centralized formations and directed formations for decentralized formations. In each case, we determine differential geometric conditions that

Paulo Tabuada; George J. Pappas; Pedro Lima

2001-01-01

253

Calcification, Storm Damage and Population Resilience of Tabular Corals under Climate Change  

PubMed Central

Two facets of climate change–increased tropical storm intensity and ocean acidification–are expected to detrimentally affect reef-building organisms by increasing their mortality rates and decreasing their calcification rates. Our current understanding of these effects is largely based on individual organisms’ short-term responses to experimental manipulations. However, predicting the ecologically-relevant effects of climate change requires understanding the long-term demographic implications of these organism-level responses. In this study, we investigate how storm intensity and calcification rate interact to affect population dynamics of the table coral Acropora hyacinthus, a dominant and geographically widespread ecosystem engineer on wave-exposed Indo-Pacific reefs. We develop a mechanistic framework based on the responses of individual-level demographic rates to changes in the physical and chemical environment, using a size-structured population model that enables us to rigorously incorporate uncertainty. We find that table coral populations are vulnerable to future collapse, placing in jeopardy many other reef organisms that are dependent upon them for shelter and food. Resistance to collapse is largely insensitive to predicted changes in storm intensity, but is highly dependent on the extent to which calcification influences both the mechanical properties of reef substrate and the colony-level trade-off between growth rate and skeletal strength. This study provides the first rigorous quantitative accounting of the demographic implications of the effects of ocean acidification and changes in storm intensity, and provides a template for further studies of climate-induced shifts in ecosystems, including coral reefs.

Madin, Joshua S.; Hughes, Terry P.; Connolly, Sean R.

2012-01-01

254

Results of open pararenal abdominal aortic aneurysm repair: Tabular review of the literature.  

PubMed

Open surgical repair of complex abdominal aortic aneurysms requires more extensive dissection and aortic clamping above the renal or mesenteric arteries. Although results of open surgical series have shown variation, morbidity and mortality is higher compared with infrarenal aortic aneurysm repair. Potential complications include renal insufficiency, mesenteric ischemia, multisystem organ failure, and death. Although endovascular treatment with fenestrated and branched endografts might potentially decrease the risk of complications and mortality, its role is not yet defined and the technology is not widely available. Issues related to durability of the procedure and secondary interventions might limit its application to patients with higher risk or those with hostile anatomy. This article summarizes the clinical results of open surgical repair of pararenal abdominal aortic aneurysms to provide a benchmark for comparison with results of endovascular treatment, using fenestrated and branched techniques. PMID:21172590

Tallarita, Tiziano; Sobreira, Marcone L; Oderich, Gustavo S

2011-01-01

255

ARI Survey of Army Recruits 1984: Tabular Description of NPS Army National Guard Accessions.  

National Technical Information Service (NTIS)

The ARI Survey of Army Recruits (more commonly known as the New Recruits Survey (NRS)) is conducted to obtain information on the characteristics, enlistment motivations, attitudes, and knowledge of recruits at the point of their initial entry into the U.S...

J. F. Celeste J. B. Davis D. C. Garver V. F. Nieva V. F. Ramsey

1986-01-01

256

1988 Troop Program Unit Attritee Research Project: Tabular Descriptions of the Army National Guard.  

National Technical Information Service (NTIS)

The 1988 Troop Program Unit (TPU) attritee research project forms a part of the FY87-88 U.S. Army Reserve (USAR) Personnel Research Strategy to enhance retention in the Total Army. The purpose of the survey was to identify the causes of early attrition fr...

A. C. Theisen R. M. Bray

1990-01-01

257

Kinematic and seismic analysis of giant tabular iceberg breakup at Cape Adare, Antarctica  

NASA Astrophysics Data System (ADS)

Satellite imagery reveals that a series of large icebergs (B15B in April 2001, C19 in June 2003, and B15A in October 2005) broke up or fractured while exiting the Ross Sea in a narrowly defined area off Cape Adare, Antarctica. Examination of recent swath-mapped bathymetric observations revealed that the principle agent of these breakups is a previously unknown 9 km long ridge with minimum depths of 215 m that we call Davey Shoal. Satellite imagery shows that the icebergs are driven into the shoal by coastal currents that converge over the narrow continental shelf. One of the icebergs, the 120 km by 30 km B15A, was instrumented with a seismograph, GPS, and fluxgate compass. This instrumentation provided a unique opportunity to establish the details of the iceberg kinematics that were not revealed by satellite imagery alone and to correlate seismic events observed both on the iceberg and in the far field during breakup. B15A fractured from multiple strikes against Davey Shoal and the adjacent Possession Islands; these strikes were driven by the combination of tidal currents and the coastal mean flow. The periods of iceberg-sourced seismic radiation were correlated with the strikes. The iceberg- and land-based seismic signals showed that the iceberg fracture, its sliding across the shoals, and the ice-on-ice stick-slip contacts among the postbreakup iceberg fragments generated the strong chaotic and harmonic tremor episodes that were observed at distances as far as the South Pole, where these signals propagated as seismically coupled hydroacoustic T phases.

Martin, Seelye; Drucker, Robert; Aster, Richard; Davey, Fred; Okal, Emile; Scambos, Ted; Macayeal, Douglas

2010-06-01

258

The Tabular Mode: Not Just Another Way To Represent a Function.  

ERIC Educational Resources Information Center

Reports on two investigations examining students' thinking processes with regard to functions. Concludes that students often relied on a table or some variation of a table as a cognitive link advancing the development of their reasoning about underlying function relationships. (Author/MM)

Hines, Ellen; Klanderman, David B.; Khoury, Helen

2001-01-01

259

LIMAT: a computer program for least-squares inversion of magnetic anomalies over long tabular bodies  

NASA Astrophysics Data System (ADS)

A popular method for the inversion of magnetic anomalies in total vertical or horizontal field over thin sheet thick dike and vertical fault is presented. The magnetic anomaly over thin sheet may be expressed as a polynomial of the form FX2+ C1FX+ C2F+ C3X3+ C4X2+ C5X+ C6 The initial parameters of the source are obtained from the coefficients C1,C2,…, C6 by inverting a 6×6 matrix. The thick dike and the vertical fault are an ensemble of thin sheets. So the same initial solution obtained for the thin sheet model can be used for the thick dike and the vertical fault. Besides, in this method the computer calculates the initial solution by using all the discrete magnetic anomaly values and the corresponding distances as an input. The initial solution thus obtained is modified in an iterative process using non-linear least-squares regression by employing Marquardt's algorithm. The regional value that is subjective in manual interpretation is also adjusted in this method to obtain a close fit. A computer program in FORTRAN 77 is presented and used to interpret synthetic and practical data and the efficacy of the results are discussed.

Raju, D. Ch. Venkata

2003-02-01

260

Construction of a wide-range tabular equation of state for copper  

SciTech Connect

A global equation of state (EOS) for copper has been constructed, ranging from densities of 10/sup -3/--10/sup 3/ Mg/m/sup 3/ and from ambient temperatures to 5 x 10/sup 4/ eV (1 eV = 11604.5 K). Six different theoretical models were used: a soft sphere liquid model at low temperatures below melt density; an ionization equilibrium model based on a modified Saha method at moderate temperatures in expansion; a nonideal plasma theory for high temperatures; a modified Thomas--Fermi--Kirzhnits model in compression; rigorous electron band theory for the zero degree isotherm; and a semiempirical model in the solid-liquid-vapor region. Assembly of the EOS will be described. Agreement with existing experimental data is good.

Trainor, K.S.

1983-05-01

261

Developments in West Coast area in 1979. [Tabular data and maps  

Microsoft Academic Search

New-field discoveries in California were down in 1979 from the previous year. The total exploratory footage drilled was slightly lower, but the total number of successful exploratory wells was up 19% from 1978. One new oil field and 5 new gas field discoveries were reported in California. None of these discoveries appear to be of major size. During 1979, hydrocarbons

R. C. Blaisdell; T. W. Dignes

1980-01-01

262

Science Sampler: Formative assessment guideposts  

NSDL National Science Digital Library

A formative assessment can provide a snapshot of what a student knows and is able to do. Use this approach to close the gap between what is known and what needs to be known through informative feedback. Explore the use of formative assessments with navigational help from these six guideposts.

Ayala, Carlos

2005-01-01

263

Mediating Among Diverse Data Formats.  

National Technical Information Service (NTIS)

The growth of the Internet and other global networks has made large quantities of data available in a wide variety of formats. Unfortunately, most programs are only able to interpret a small number of formats, and cannot take advantage of data in unfamili...

J. Ockerbloom

1998-01-01

264

Information-Theoretic Image Formation  

Microsoft Academic Search

The emergent role of information theory in image formation is surveyed. Unlike the subject of information-theoretic communication theory, information-theoretic imaging is far from a mature subject. The possible role of information theory in prob- lems of image formation is to provide a rigorous framework for defining the imaging problem, for defining measures of optimality used to form estimates of images,

Joseph A. O'sullivan; Richard E. Blahut; Donald L. Snyder

1998-01-01

265

Formative Assessment: A Critical Review  

ERIC Educational Resources Information Center

This paper covers six interrelated issues in formative assessment (aka, "assessment for learning"). The issues concern the definition of formative assessment, the claims commonly made for its effectiveness, the limited attention given to domain considerations in its conceptualisation, the under-representation of measurement principles in that…

Bennett, Randy Elliot

2011-01-01

266

Morse theory and formation control  

Microsoft Academic Search

Formation shape control for a collection of point agents is concerned with devising decentralized control laws which will ensure that the formation will move so that certain inter-agent distances assume prescribed values. A number of algorithms based on steepest descent of an error function have been suggested for various problems, and all display the existence of incorrect equilibria, though often

Brian D. O. Anderson

2011-01-01

267

Formation of the solar system  

Microsoft Academic Search

The overall evolution of the solar system is discussed in terms of what is called the Kyoto model. Starting from the formation of the solar nebula, a multistep process is followed in detail, including growth and sedimentation of dust grains in the nebula, formation of planetesimals due to fragmentation of a dust layer, radial migration and accumulation of planetesimals to

C. Hayashi; K. Nakazawa; Y. Nakagawa

1985-01-01

268

Tooth formation - delayed or absent  

MedlinePLUS

Delayed or absent tooth formation; Teeth - delayed or absent formation ... The timing of the first appearance of teeth varies. Most infants get their first tooth between 6 and 9 months, although earlier or later eruption may be normal. In some cases, ...

269

Pattern Formation Using Multiple Robots  

Microsoft Academic Search

Pattern formation is one of typical problems in the field of multi-robot cooperation. It can be applied to complex application scenarios such as region coverage and path exploration. Compare to traditional multi-robot coordination algorithm, the method based on swarm robots to solve the issue of pattern formation has better scalability and dynamic adaptability and robustness. In this demo, we propose

Jun Zeng; Daoyong Liu; Alei Liang; Haibing Guan

2009-01-01

270

Professional Development through Formative Evaluation  

ERIC Educational Resources Information Center

Formative evaluation and its associated methodology of reflection on practice are used extensively in academic staff development. In reflecting on formative evaluation processes in both more traditional and newer programmes conducted at a university of technology, a number of variables reported in the literature were observed to have influenced…

Nsibande, Rejoice; Garraway, James

2011-01-01

271

Pellicle formation in Shewanella oneidensis  

PubMed Central

Background Although solid surface-associated biofilm development of S. oneidensis has been extensively studied in recent years, pellicles formed at the air-liquid interface are largely overlooked. The goal of this work was to understand basic requirements and mechanism of pellicle formation in S. oneidensis. Results We demonstrated that pellicle formation can be completed when oxygen and certain cations were present. Ca(II), Mn(II), Cu(II), and Zn(II) were essential for the process evidenced by fully rescuing pellicle formation of S. oneidensis from the EDTA treatment while Mg (II), Fe(II), and Fe(III) were much less effective. Proteins rather than DNA were crucial in pellicle formation and the major exopolysaccharides may be rich in mannose. Mutational analysis revealed that flagella were not required for pellicle formation but flagellum-less mutants delayed pellicle development substantially, likely due to reduced growth in static media. The analysis also demonstrated that AggA type I secretion system was essential in formation of pellicles but not of solid surface-associated biofilms in S. oneidensis. Conclusion This systematic characterization of pellicle formation shed lights on our understanding of biofilm formation in S. oneidensis and indicated that the pellicle may serve as a good research model for studying bacterial communities.

2010-01-01

272

Formation of the Outer Planets  

Microsoft Academic Search

Models of the origins of gas giant planets and ‘ice’ giant planets are discussed and related to formation theories of both smaller objects (terrestrial planets) and larger bodies (stars). The most detailed models of planetary formation are based upon observations of our own Solar System, of young stars and their environments, and of extrasolar planets. Stars form from the collapse,

Jack J. Lissauer

2005-01-01

273

Galaxy Collisions and Star Formation  

Microsoft Academic Search

We present a brief overview of some recent observations of colliding galaxies and relevant numerical simulations. These are compared, and details of the locations and history of collision induced star formation are explored, with possible application to star formation at earlier epochs.

Susan A. Lamb; Nathan C. Hearn

2000-01-01

274

Galaxy Collisions and Star Formation  

Microsoft Academic Search

We present a brief overview of some recent observations of colliding galaxies\\u000aand relevant numerical simulations. These are compared, and details of the\\u000alocations and history of collision induced star formation are explored, with\\u000apossible application to star formation at earlier epochs.

Susan A. Lamb; Nathan C. Hearn

2000-01-01

275

The Apennine Bench Formation revisited  

NASA Technical Reports Server (NTRS)

The Apennine Bench Formation consists of pre-mare light plains materials that crop out south of the crater Archimedes, inside the Imbrium basin. This material was ascribed to either impact or volcanic origins. The characteristics of Apollo 15 KREEP basalts and the Apennine Bench Formation are reviewed to determine whether their characteristics are compatible with a volcanic origin.

Spudis, P. D.; Hawke, B. R.

1985-01-01

276

Formation of interstellar anions  

NASA Astrophysics Data System (ADS)

Formation of interstellar anions: M.L. Senent. The recent detection of negative charged species in the ISM1 has instigated enthusiasm for anions in the astrophysical community2. Many of these species are new and entail characterization. How they are formed in astrophysical sources is a question of major relevance. The anion presence in ISM was first predicted theoretically on the basis of electron affinities and on the negative linear chain molecular stabilities. Although very early, they were considered in astrochemical models3-4, their discovery is so recent because their abundances seem to be relatively low. These have to be understood in terms of molecular stabilities, reaction probabilities and radiative and collisional excitations. Then, we present our theoretical work on even carbon chains type Cn and CnH (n=2,4,6) focused to the understanding of anion abundances. We use highly correlated ab initio methods. We performed spectroscopic studies of various isomers that can play important roles as intermediates5-8. In previous papers9-10, we compared C2H and C2H- collisional rates responsible for observed line intensities. Actually, we study hydrogen attachment (Cn +H ? CnH and Cn- +H ? CnH-) and associative detachment processes (Cn- +H ? CnH +e-) for 2, 4 and 6 carbon atom chains11. [1] M.C.McCarthy, C.A.Gottlieb, H.Gupta, P.Thaddeus, Astrophys.J, 652, L141 (2006) [2] V.M.Bierbaum, J.Cernicharo, R.Bachiller, eds., 2011, pp 383-389. [3] A. Dalgarno, R.A. Mc Cray, Astrophys.J,, 181, 95 (1973) [4] E. Herbst E., Nature, 289, 656 (1981); [5] H.Massó, M.L.Senent, P.Rosmus, M.Hochlaf, J.Chem.Phys., 124, 234304 (2006) [6] M.L.Senent, M.Hochlaf, Astrophys. J. , 708, 1452(2010) [7] H.Massó, M.L.Senent, J.Phys.Chem.A, 113, 12404 (2009) [8] D. Hammoutene, M.Hochlaf, M.L.Senent, submitted. [9] A. Spielfiedel, N. Feautrier, F. Najar, D. ben Abdallah, F. Dayou, M.L. Senent, F. Lique, Mon.Not.R.Astron.Soc., 421, 1891 (2012) [10] F.Dumouchel, A, Spielfieldel , M.L.Senent, N.Feautrier, Chem. Phys. Lett., 533, 6 (2012) [11] M.L.Senent, M.Hochlaf, submitted

Senent, Maria Luisa

2012-05-01

277

The formation of Pangea  

NASA Astrophysics Data System (ADS)

The making of Pangea is the result of large-scale amalgamation of continents and micro-continents, which started at the end of the Neoproterozoic with the formation of Gondwana. As pieces were added to Gondwana on its South-American, Antarctica and Australia side, ribbon-like micro-continents were detached from its African and South-Chinese side: Cadomia in the late Neoproterozoic, Avalonia and Hunia in the Ordovician, Galatia in the Devonian and Cimmeria in the Permian. Cadomia was re-accreted to Gondwana, but the other ribbon-continents were accreted to Baltica, North-China, Laurussia or Laurasia. Finding the origin of these numerous terranes is a major geological challenge. Recently, a global plate tectonic model was developed together with a large geological/geodynamic database, at the Lausanne University, covering the last 600 Ma of the Earth's history. Special attention was given to the placing of Gondwana derived terranes in their original position, using all possible constraints. We propose here a solution for the Variscan terranes, another paper deals with the Altaids. The Galatian super-terrane was detached from Gondwana in the Devonian, during the opening of Paleotethys, and was quickly separated into four sub-terranes that started to by-pass each other. The leading terranes collided at the end of the Devonian with the Hanseatic terrane detached from Laurussia. In the Carboniferous, Gondwana started to impinge onto the amalgamated terranes, creating the Variscan chain and the Pangean super-continent. East of Spain Paleotethys remained opened until the Triassic, subducting northward under Laurasia. Roll-back of the Paleotethyan slab triggered the collapse of most of the European Variscan orogen, which was replaced by series of Permian rifts, some of them becoming oceanized back-arc basins during the Triassic. Major force changes at the Pangean plate limits at the end of the Triassic provoked its break-up, through the opening of the proto-Caribbean, central-Atlantic, Alpine-Tethys oceanic seaways.

Stampfli, G. M.; Hochard, C.; Vérard, C.; Wilhem, C.; vonRaumer, J.

2013-05-01

278

21 CFR 100.1 - Petitions requesting exemption from preemption for State or local requirements.  

Code of Federal Regulations, 2013 CFR

...standard format, such as ASCII format. (Petitioners interested in submitting a disk should contact the Center for Food Safety and Applied Nutrition for details.) (3) Petitions for exemption from preemption for a State requirement...

2013-04-01

279

Star formation rates and starbursts  

NASA Astrophysics Data System (ADS)

Understanding star formation rates in galaxies requires understanding both the rate at which molecular clouds form and the efficiency of star formation in these clouds. The efficiency of star formation is probably limited mainly by the destruction of star-forming clouds by ionization, and molecular clouds probably form by a combination of large-scale gravitational instabilities and cloud accretion processes. These hypotheses lead to quantitative predictions that agree well with observational estimates of both the efficiency of star formation and the timescale for converting gas into stars. The predicted timescale depends mainly on the surface density of gas in a galaxy, and the predicted star formation rate per unit area is proportional to the square of the gas surface density, similar to the original Schmidt law. A burst of star formation requires an exceptionally high gas surface density; this results in both a short timescale and a high efficiency for star formation. The gas feeding a starburst must be assembled rapidly into the starburst region, and this requires a violent large-scale disturbance to the interstellar medium in a galaxy, such as that produced by a tidal interaction or merger with another galaxy.

Larson, Richard B.

280

Antihydrogen Formation using Cold Plasmas  

SciTech Connect

Antihydrogen, the antimatter counterpart of the hydrogen atom, can be formed by mixing cold samples of antiprotons and positrons. In 2002 the ATHENA collaboration succeeded in the first production of cold antihydrogen. By observing and imaging the annihilation products of the neutral, non-confined, antihydrogen atoms annihilating on the walls of the trap we can observe the production in quasi-real-time and study the dynamics of the formation mechanism. The formation mechanism strongly influences the final state of the formed antihydrogen atoms, important for future spectroscopic comparison with hydrogen. This paper briefly summarizes the current understanding of the antihydrogen formation in ATHENA.

Madsen, N.; Bowe, P.D.; Hangst, J.S. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Amoretti, M.; Carraro, C.; Macri, M.; Testera, G.; Variola, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, I-16146 Genova (Italy); Amsler, C.; Johnson, I.; Pruys, H.; Regenfus, C. [Physik-Institut, Zuerich University, CH-8057 Zurich (Switzerland); Bonomi, G.; Bouchta, A.; Doser, M.; Kellerbauer, A.; Landua, R. [PH Department, CERN, Geneva (Switzerland); Cesar, C.L. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21945-970 (Brazil); Charlton, M.; Joergensen, L.V. [Department of Physics, University of Wales Swansea, Swansea SA2 8PP (United Kingdom)] [and others

2004-10-20

281

Dynamics of rock varnish formation  

SciTech Connect

Our studies of rock varnish from the southwestern United States suggest that the Mn-phase in rock varnish has neither the chemistry nor the crystal structure of birnessite. Rather, the Mn-rich phase is non-crystalline and contains Ba, Ca, Fe, Al, and P. Unknowns concerning the formation of this non-crystalline Mn phase must be resolved before researchers are able to define chemical parameters of rock varnish formation based upon conditions of formation of the Mn phase. 6 refs., 9 figs.

Raymond, R. Jr.; Reneau, S.L.; Guthrie, G.D. Jr.; Bish, D.L.; Harrington, C.D.

1991-01-01

282

Holographic grating formation in photopolymers  

NASA Astrophysics Data System (ADS)

We introduce a model describing real-time grating formation in holographic photopolymers, assuming that the diffusion of free monomers is much faster than the grating formation. This model, which combines polymerization kinetics with results from coupled-wave theory, indicates that the grating formation time depends sublinearly on the average holographic recording intensity and the beam intensity ratio controls the grating index modulation at saturation. We validate the model by comparing its predictions with the results of experiments in which DuPont HRF-150X001 photopolymer was used.

Piazzolla, Sabino; Jenkins, B. Keith

1996-07-01

283

Amyloid beta mediates memory formation  

PubMed Central

The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid ? (1–42) peptide (A?[1–42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated, endogenous A? in normal hippocampi mediates learning and memory formation. Furthermore, hippocampal injection of picomolar concentrations of exogenous A?(1–42) enhances memory consolidation. Correlative data suggest that A? peptides may exert their function via nicotinic acethylcoline receptors. Hence, A? peptides, including A?(1–42), play an important physiological role in hippocampal memory formation.

Garcia-Osta, Ana; Alberini, Cristina M.

2009-01-01

284

The physics of planetesimal formation  

NASA Technical Reports Server (NTRS)

Physical processes involved in the planetesimal formation are discussed with special attention given to the nature of aerodynamic interactions between solid bodies and gas in the solar nebula. It is emphasized that the model of planetesimal formation by gravitational instability of a dust layer yields predictions that are simple but almost certainly wrong. It is suggested instead that the formation of planetesimals began with the process of coagulation of grains into larger aggregates, and that gravitational forces became more important than gas drag only after objects as large as many meters in diameter had formed.

Weidenschilling, Stuart J.; Donn, Bertram D.; Meakin, Paul

1989-01-01

285

Energetic condition for carbyne formation  

NASA Astrophysics Data System (ADS)

Although hypothesized in the carbon phase diagram, a general criterion to explain the formation of sp bonded carbon chains (carbynes) is lacking. We propose an energetic approach to explain carbyne formation in two conceptually simple configurations in which impact events play a major role, namely, in ancient meteorite craters and in the synthesis of cluster-assembled carbon films. For both configurations the calculated energies per particle equal each other. In one case pressure and temperature values match the carbyne region in the carbon phase diagram. A threshold range of 130-180 eV particle -1 is suggested as an energetic condition for carbyne formation.

Lamperti, A.; Ossi, P. M.

2003-07-01

286

Dissipative processes in galaxy formation.  

PubMed Central

A galaxy commences its life in a diffuse gas cloud that evolves into a predominantly stellar aggregation. Considerable dissipation of gravitational binding energy occurs during this transition. I review here the dissipative processes that determine the critical scales of luminous galaxies and the generation of their morphology. The universal scaling relations for spirals and ellipticals are shown to be sensitive to the history of star formation. Semiphenomenological expressions are given for star-formation rates in protogalaxies and in starbursts. Implications are described for elliptical galaxy formation and for the evolution of disk galaxies.

Silk, J

1993-01-01

287

Germline cyst formation in Drosophila.  

PubMed

In a wide variety of organisms, gametes develop within clusters of interconnected germline cells called cysts. Four major principles guide the construction of most cysts: synchronous division, a maximally branched pattern of interconnection between cells, specific changes in cyst geometry, and cyst polarization. The fusome is a germline-specific organelle that is associated with cyst formation in many insects and is likely to play an essential role in these processes. This review examines the cellular and molecular processes that underlie fusome formation and cyst initiation, construction, and polarization in Drosophila melanogaster. The studies described here highlight the importance of cyst formation to the subsequent development of functional gametes. PMID:9442902

de Cuevas, M; Lilly, M A; Spradling, A C

1997-01-01

288

Constraining Corona Formation on Venus  

NASA Astrophysics Data System (ADS)

We model the formation of off-rift coronae at Parga Chasma in order to understand how Venus loses its heat. We find the data required to make proper comparisons between models and observations is lacking.

Piskorz, D.; Elkins-Tanton, L. T.; Smrekar, S. E.

2014-05-01

289

Full Capability Formation Flight Control.  

National Technical Information Service (NTIS)

The subject of automatic formation flight control is of current interest to the development of Unmanned Aerial Vehicles (UAV). Previous control approaches have been refined in this work to allow more robust maneuvering and to include a fourth control para...

R. K. Osteroos

2005-01-01

290

Formation of the Solar System  

NSDL National Science Digital Library

This chapter from an online astronomy course briefly describes the formation of the solar system from an accretionary disk. Links to additional resources, a homework assignment, and a quiz are included.

Barnes, Joshua

291

Metamorphism and Metamorphic Formation & Deformation  

NSDL National Science Digital Library

This presentation on metamorphis and metamorphic formation was created by Martin Streck of Portland State University. The lesson provides an overview on the deformation of metamorphic rocks and minerals and includes helpful diagrams and images.

Streck, Martin

2008-04-25

292

Optimal Reconfiguration of Tetrahedral Formations.  

National Technical Information Service (NTIS)

The problem of minimum-fuel formation reconfiguration for the Magnetospheric Multi- Scale (MMS) mission is studied. This reconfiguration trajectory optimization problem can be posed as B nonlinear optimal control problem. In this research, this optimal co...

G. Huntington S. P. Hughes

2003-01-01

293

Method for treating underground formations  

SciTech Connect

Disclosed is a method for treating subterranean formations such as underground petroleum-containing formations penetrated by a well, and particularly a formation penetrated by a producing well which formation contain a plurality of zones, one or more of which are producing petroleum and one or more of which are producing water. The treatment selectively reduces the permeability of the water-producing intervals without adversely affecting the permeability of the oil producing intervals, thereby reducing the production of water and reducing the water-oil ratio of the fluid being produced from the well. The treatment method involves introducing an effective amount of a liquid comprising a hydrocarbon having dispersed therein an unhydrated water swellable clay such as bentonite, a sodium montmorillonite. The clay swells on contacting water in the water-producing intervals and plugs or reduces the permeability of the flow channels in the water-producing intervals.

Noles, J.R.; Walker, C.O.; White, N.F.

1981-04-14

294

Vertical formations demand unique treatments  

SciTech Connect

In the US midcontinent area, major thrust faults trap large quantities of hydrocarbons in the down-thrown fault block. As exploration of these thrust fault structures continues, the application of extended reach and horizontal well bores will increase. Formations in deep structures are apt to have lower porosity and permeability than the currently developed thrust faults and thus, require fracture stimulation. In addition, the portion of the formation closest to the fault may be subjected to folding resulting in a vertical formation penetrated by a horizontal well bore. Low porosity and vertical bedding were encountered in the City of Lawton No. 1-34, an 18,088-ft wildcat (14,627-ft TVD) in Caddo County, Oklahoma. This article details methods to overcome the obstacles that well bore and formation geometry present to fracture stimulation operations in the 17,714-ft (14,614-ft TVD) Britt sand.

Fairchild, K. [Fina Oil and Chemical Co., Midland, TX (United States)

1996-04-01

295

Cosmic strings and galaxy formation  

NASA Technical Reports Server (NTRS)

The cosmogonical model proposed by Zel'dovich and Vilenkin (1981), in which superconducting cosmic strings act as seeds for the origin of structure in the universe, is discussed, summarizing the results of recent theoretical investigations. Consideration is given to the formation of cosmic strings, the microscopic structure of strings, gravitational effects, cosmic string evolution, and the formation of galaxies and large-scale structure. Simulation results are presented in graphs, and several outstanding issues are listed and briefly characterized.

Bertschinger, Edmund

1989-01-01

296

Flight Formation of Multiple UAVs  

Microsoft Academic Search

\\u000a To conclude the whole monograph, we feature respectively in Chaps. 10 and 11 the applications of the unmanned rotorcraft systems constructed. More specifically, in Chap. 10, we present some basic results\\u000a on flight formation and collision avoidance of multiple unmanned systems. We adopt the leader-follower pattern to maintain\\u000a a fixed geometrical formation while navigating the unmanned rotorcraft following certain trajectories. In order

Guowei Cai; Ben M. Chen; Tong Heng Lee

297

Thiol isomerases in thrombus formation.  

PubMed

Protein disulfide isomerase (PDI), ERp5, and ERp57, among perhaps other thiol isomerases, are important for the initiation of thrombus formation. Using the laser injury thrombosis model in mice to induce in vivo arterial thrombus formation, it was shown that thrombus formation is associated with PDI secretion by platelets, that inhibition of PDI blocked platelet thrombus formation and fibrin generation, and that endothelial cell activation leads to PDI secretion. Similar results using this and other thrombosis models in mice have demonstrated the importance of ERp5 and ERp57 in the initiation of thrombus formation. The integrins, ?IIb?3 and ?V?3, play a key role in this process and interact directly with PDI, ERp5, and ERp57. The mechanism by which thiol isomerases participate in thrombus generation is being evaluated using trapping mutant forms to identify substrates of thiol isomerases that participate in the network pathways linking thiol isomerases, platelet receptor activation, and fibrin generation. PDI as an antithrombotic target is being explored using isoquercetin and quercetin 3-rutinoside, inhibitors of PDI identified by high throughput screening. Regulation of thiol isomerase expression, analysis of the storage, and secretion of thiol isomerases and determination of the electron transfer pathway are key issues to understanding this newly discovered mechanism of regulation of the initiation of thrombus formation. PMID:24677236

Furie, Bruce; Flaumenhaft, Robert

2014-03-28

298

Diagenetic Microcrystalline Opal Varieties from the Monterey Formation, CA: HRTEM Study of Structures and Phase Transformation Mechanisms  

NASA Technical Reports Server (NTRS)

Microcrystalline opal varieties form as intermediary precipitates during the diagenetic transformation of biogenically precipitated non-crystalline opal (opal-A) to microquartz. With regard to the Monterey Formation of California, X-ray powder diffraction studies have shown that a decrease in the primary d-spacing of opal-CT toward that of cristobalite occurs with increasing diagenesis. The initial timing of opal-CT/quartz formation and the value of the primary opal-CT d-spacing, are influenced by the sediment. lithology. Transmission electron microscopy methods (CTEM/HRTEM) were used to investigate the structure of the diagenetic phases and establish transformation mechanisms between the varieties of microcrystalline opals in charts and porcelanites from the Monterey Formation. HRTEM images revealed that the most common fibrous varieties of microcrystalline opals contain varying amounts of structural disorder. Finite lamellar units of cristobalite-and tridymite-type. layer sequences were found to be randomly stacked in a direction perpendicular to the fiber axis. Disordered and ordered fibers were found to have coprecipitated within the same radial fiber bundles that formed within the matrix of the Most siliceous samples. HRTEM images, which reveal that the fibers within radial and lepispheric fiber bundles branch non-crystallographically, support an earlier proposal that microspheres in chert grow via a spherulitic growth mechanism. A less common variety of opal-CT was found to be characterized by non-parallel (low-angle) stacking sequences that often contain twinned lamellae. Tabular-shaped crystals of orthorhombic tridymite (PO-2) were also identified in the porcelanite samples. A shift in the primary d-spacing of opal-CT has been interpreted as an indication of solid-state ordering g toward a predominantly cristobalite structure, (opal-C). Domains of opal-C were identified as topotactically-oriented overgrowths on discrete Sections of opal-CT fibers and as lamellar domains within relict opal-CT fibers. These findings indicate that the type of transformation mechanism depends upon the primary structural characteristics of the authigenic opaline. varieties that are in turn influenced by the sediment lithology.

Cady, Sherry L.; Wenk, H.-R.; DeVincenzi, Don (Technical Monitor)

1994-01-01

299

Compaction localization in the porous carbonates of Bolognano Formation (Majella Mountain, Italy)  

NASA Astrophysics Data System (ADS)

Recent field-based papers documented the presence of bed-parallel compaction bands within two different carbonate lithofacies (16%>porosity>33%) belonging to the Oligo-Miocene Bolognano Formation. Based upon field and thin section analyses, the aforementioned structural elements, which consist of narrow tabular bands characterized by a local porosity reduction, were interpreted as burial-related structures that accommodate volumetric strain by means of grain rotation/sliding, grain crushing, intergranular pressure solution and pore collapse. Aimed at constraining the pressure conditions at which compaction bands develop, and at investigating the rock anisotropy (e.g. grain and pore size/shape and cement amount/type) that may promote compaction localization in the studied carbonates, we carried out a set of triaxial compression experiments under dry conditions and room temperature, at confining pressures ranging between 5 and 35 MPa. The deformed specimens, characterized by a porosity comprised between 26% and 31%, were cored out from a large hand sample collected from the carbonate lithofacies more densely affected by natural compaction bands. During the deformation, the samples displayed a shear-enhanced compaction behavior and strain hardening, associated with various patterns of strain localization (i.e. compactive shear bands and compaction bands). The brittle ductile transition was observed at 12.5 MPa of confining pressure, and the pressure conditions at which compaction bands nucleate were constrained. A positive correlation between confining pressure increase and the angular value formed by individual deformation band and the major principal stress was observed. In addition, to the aforementioned experiments, we also performed triaxial compression tests on specimens cored at different orientations with respect to the sedimentary bedding (i.e. perpendicular, parallel and at 45 deg.), at 25 MPa of confining pressure. Focusing at the angle formed by individual deformation bands and the major principal compression direction, we conclude that it is strongly influenced by the original rock anisotropy, hence by the angle between the major principal compression direction and bedding orientation, clearly shown by the grain alignment and rock laminations.

Cilona, A.; Faulkner, F. R.; Baud, P.; Rustichelli, A.; Tondi, E.; Agosta, F.

2012-04-01

300

Compaction localization in the porous carbonates of Bolognano Formation (Majella Mountain, Italy)  

NASA Astrophysics Data System (ADS)

Recent field-based papers documented the presence of bed-parallel compaction bands within two different carbonate lithofacies (16%>porosity>33%) belonging to the Oligo-Miocene Bolognano Formation. Based upon field and thin section analyses, the aforementioned structural elements, which consist of narrow tabular bands characterized by a local porosity reduction, were interpreted as burial-related structures that accommodate volumetric strain by means of grain rotation/sliding, grain crushing, intergranular pressure solution and pore collapse. Aimed at constraining the pressure conditions at which compaction bands develop, and at investigating the rock anisotropy (e.g. grain and pore size/shape and cement amount/type) that may promote compaction localization in the studied carbonates, we carried out a set of triaxial compression experiments under dry conditions and room temperature, at confining pressures ranging between 5 and 35 MPa. The deformed specimens, characterized by a porosity comprised between 26% and 31%, were cored out from a large hand sample collected from the carbonate lithofacies more densely affected by natural compaction bands. During the deformation, the samples displayed a shear-enhanced compaction behavior and strain hardening, associated with various patterns of strain localization (i.e. compactive shear bands and compaction bands). The brittle ductile transition was observed at 12.5 MPa of confining pressure, and the pressure conditions at which compaction bands nucleate were constrained. A positive correlation between confining pressure increase and the angular value formed by individual deformation band and the major principal stress was observed. In addition, to the aforementioned experiments, we also performed triaxial compression tests on specimens cored at different orientations with respect to the sedimentary bedding (i.e. perpendicular, parallel and at 45 deg.), at 25 MPa of confining pressure. Focusing at the angle formed by individual deformation bands and the major principal compression direction, we conclude that it is strongly influenced by the original rock anisotropy, hence by the angle between the major principal compression direction and bedding orientation, clearly shown by the grain alignment and rock laminations. Quantitative microstructural and petrophysical analyses, aimed at assessing the spatial distribution of micro-cracks as well as measuring the 3D porosity, were carried out on both deformed and pristine carbonates by integrating microscope and x-ray tomography techniques.

Baud, P.; Cilona, A.; Faulkner, D. R.; Rustichelli, A.; Tondi, E.; Agosta, F.; Vinciguerra, S.; Arzilli, F.

2012-12-01

301

The dynamics of latifundia formation.  

PubMed

Land tenure inequity is a major social problem in developing nations worldwide. In societies, where land is a commodity, inequities in land tenure are associated with gaps in income distribution, poverty and biodiversity loss. A common pattern of land tenure inequities through the history of civilization has been the formation of latifundia [Zhu?ngyuán in chinese], i.e., a pattern where land ownership is concentrated by a small fraction of the whole population. Here, we use simple Markov chain models to study the dynamics of latifundia formation in a heterogeneous landscape where land can transition between forest, agriculture and recovering land. We systematically study the likelihood of latifundia formation under the assumption of pre-capitalist trade, where trade is based on the average utility of land parcels belonging to each individual landowner during a discrete time step. By restricting land trade to that under recovery, we found the likelihood of latifundia formation to increase with the size of the system, i.e., the amount of land and individuals in the society. We found that an increase of the transition rate for land use changes, i.e., how quickly land use changes, promotes more equitable patterns of land ownership. Disease introduction in the system, which reduced land profitability for infected individual landowners, promoted the formation of latifundia, with an increased likelihood for latifundia formation when there were heterogeneities in the susceptibility to infection. Finally, our model suggests that land ownership reforms need to guarantee an equitative distribution of land among individuals in a society to avoid the formation of latifundia. PMID:24376597

Chaves, Luis Fernando

2013-01-01

302

Isolated star formation: from cloud formation to core collapse.  

PubMed

The formation of stars is one of the most fundamental problems in astrophysics, as it underlies many other questions, on scales from the formation of galaxies to the formation of the solar system. The physical processes involve the turbulent behavior of a partially ionized medium containing a non-uniform magnetic field. Current debate centers around the time taken for turbulence to decay and the relative importance of the roles played by magnetic fields and turbulence. Technological advances such as millimeter-wave cameras have made possible observations of the temperature and density profiles, and statistical calculations of the lifetimes, of objects collapsing under their own self-gravity and those on the verge of collapse. Increased computing power allows more complex models to be made that include magnetic and turbulent effects. No current model can reproduce all of the observations. PMID:11778038

Ward-Thompson, Derek

2002-01-01

303

An XML portable chart format.  

PubMed

The clinical chart remains the fundamental record of outpatient clinical care. As this information migrates to electronic form, there is an opportunity to create standard formats for transmitting these charts. This paper describes work toward a Portable Chart Format (PCF) that can represent the relevant aspects of an outpatient chart. The main goal of the format is to provide a packaging medium for outpatient clinical charts in a transfer of care scenario. A secondary goal is to support the aggregation of comparable clinical data for outcomes analysis. The syntax used for PCF is Extended Markup Language (XML), a W3C standard. The structure of the PCF is based on a clinically relevant view of the data. The data definitions and nomenclature used are based primarily on existing clinical standards. PMID:9929315

Chueh, H C; Raila, W F; Berkowicz, D A; Barnett, G O

1998-01-01

304

Granuloma Formation in Pulmonary Sarcoidosis  

PubMed Central

Sarcoidosis is a granulomatous disorder of unknown cause, affecting multiple organs, but mainly the lungs. The exact order of immunological events remains obscure. Reviewing current literature, combined with careful clinical observations, we propose a model for granuloma formation in pulmonary sarcoidosis. A tight collaboration between macrophages, dendritic cells, and lymphocyte subsets, initiates the first steps toward granuloma formation, orchestrated by cytokines and chemokines. In a substantial part of pulmonary sarcoidosis patients, granuloma formation becomes an on-going process, leading to debilitating disease, and sometimes death. The immunological response, determining granuloma sustainment is not well understood. An impaired immunosuppressive function of regulatory T cells has been suggested to contribute to the exaggerated response. Interestingly, therapeutical agents commonly used in sarcoidosis, such as glucocorticosteroids and anti-TNF agents, interfere with granuloma integrity and restore the immune homeostasis in autoimmune disorders. Increasing insight into their mechanisms of action may contribute to the search for new therapeutical targets in pulmonary sarcoidosis.

Broos, Caroline E.; van Nimwegen, Menno; Hoogsteden, Henk C.; Hendriks, Rudi W.; Kool, Mirjam; van den Blink, Bernt

2013-01-01

305

Deposit formation in hydrocarbon fuels  

NASA Technical Reports Server (NTRS)

The hydrocarbon fuels RP-1, commercial-grade propane, JP-7 and chemically pure propane were subjected to tests in a high pressure fuel coking apparatus in order to evaluate their thermal decomposition limits and carbon deposition rates in heated copper tubes. A fuel thermal stability parametric evaluation was conducted at 136-340 atmospheres, bulk fuel velocities of 6-30 m/sec, and tube wall temperatures of 422-811 K, and the effect of inside wall material on deposit formation was evaluated in tests using nickel-plated tubes. Results show RP-1 deposit formation at wall temperatures between 600 and 800 K, with peak deposit formation near 700 K. Substitution of deoxygenated JP-7 for RP-1 showed no improvement, and the carbon deposition rates for propane fuels were found to be higher than those of either of the kerosene fuels. Nickel plating of the tube walls significantly reduced RP-1 carbon deposition rates.

Roback, R.; Szetela, E. J.; Spadaccini, L. J.

1982-01-01

306

Structure formation in active networks  

NASA Astrophysics Data System (ADS)

Structure formation and constant reorganization of the actin cytoskeleton are key requirements for the function of living cells. Here we show that a minimal reconstituted system consisting of actin filaments, crosslinking molecules and molecular-motor filaments exhibits a generic mechanism of structure formation, characterized by a broad distribution of cluster sizes. We demonstrate that the growth of the structures depends on the intricate balance between crosslinker-induced stabilization and simultaneous destabilization by molecular motors, a mechanism analogous to nucleation and growth in passive systems. We also show that the intricate interplay between force generation, coarsening and connectivity is responsible for the highly dynamic process of structure formation in this heterogeneous active gel, and that these competing mechanisms result in anomalous transport, reminiscent of intracellular dynamics.

Köhler, Simone; Schaller, Volker; Bausch, Andreas R.

2011-06-01

307

Computational Modeling of Microabscess Formation  

PubMed Central

Bacterial infections can be of two types: acute or chronic. The chronic bacterial infections are characterized by being a large bacterial infection and/or an infection where the bacteria grows rapidly. In these cases, the immune response is not capable of completely eliminating the infection which may lead to the formation of a pattern known as microabscess (or abscess). The microabscess is characterized by an area comprising fluids, bacteria, immune cells (mainly neutrophils), and many types of dead cells. This distinct pattern of formation can only be numerically reproduced and studied by models that capture the spatiotemporal dynamics of the human immune system (HIS). In this context, our work aims to develop and implement an initial computational model to study the process of microabscess formation during a bacterial infection.

Pigozzo, Alexandre Bittencourt; Macedo, Gilson Costa; Weber dos Santos, Rodrigo; Lobosco, Marcelo

2012-01-01

308

Mathematical Models for Somite Formation  

PubMed Central

Somitogenesis is the process of division of the anterior–posterior vertebrate embryonic axis into similar morphological units known as somites. These segments generate the prepattern which guides formation of the vertebrae, ribs and other associated features of the body trunk. In this work, we review and discuss a series of mathematical models which account for different stages of somite formation. We begin by presenting current experimental information and mechanisms explaining somite formation, highlighting features which will be included in the models. For each model we outline the mathematical basis, show results of numerical simulations, discuss their successes and shortcomings and avenues for future exploration. We conclude with a brief discussion of the state of modeling in the field and current challenges which need to be overcome in order to further our understanding in this area.

Baker, Ruth E.; Schnell, Santiago; Maini, Philip K.

2009-01-01

309

Formation Flying In Highly Elliptical Orbits Initializing the Formation  

NASA Technical Reports Server (NTRS)

In this paper several methods are examined for initializing formations in which all spacecraft start in a common elliptical orbit subsequent to separation from the launch vehicle. The tetrahedron formation used on missions such as the Magnetospheric Multiscale (MMS), Auroral Multiscale Midex (AMM), and Cluster is used as a test bed Such a formation provides full three degrees-of-freedom in the relative motion about the reference orbit and is germane to several missions. The type of maneuver strategy that can be employed depends on the specific initial conditions of each member of the formation. Single-impulse maneuvers based on a Gaussian variation-of-parameters (VOP) approach, while operationally simple and intuitively-based, work only in a limited sense for a special class of initial conditions. These 'tailored' initial conditions are characterized as having only a few of the Keplerian elements different from the reference orbit. Attempts to achieve more generic initial conditions exceed the capabilities of the single impulse VOP. For these cases, multiple-impulse implementations are always possible but are generally less intuitive than the single-impulse case. The four-impulse VOP formalism discussed by Schaub is examined but smaller delta-V costs are achieved in our test problem by optimizing a Lambert solution.

Mailhe, Laurie; Schiff, Conrad; Hughes, Steven

2000-01-01

310

Conductive Anodic Filament (CAF) Formation  

NASA Astrophysics Data System (ADS)

Conductive anodic filament (CAF) is a failure mode in printed wiring boards (PWBs) which occurs under high humidity and high voltage gradient conditions. The filament, a copper salt, grows from anode to cathode along the epoxy-glass interface. Ready and Turbini (2000) identified this copper salt as the Cu 2(OH)3Cl, atacamite compound. This work has investigated the influence of polyethylene glycol (PEG) and polyethylene propylene glycol (PEPG) fluxing agents on the chemical nature of CAF. For coupons processed with PEPG flux, with and without chloride, a copper-chloride containing compound was formed in the polymer matrix. This compound was characterized using x-ray photoelectron spectroscopy (XPS) as CuCl and an electrochemical mechanism for the formation of the chloride-containing CAF has been proposed. For PEG flux, with and without chloride, it has been shown that CAF only formed, but no copper containing compound formed in the matrix. It appears for PEG fluxed coupons, a PEG-Cu-Cl complex forms, binds the available Cu and acts as a barrier to the formation of CuCl in the polymer matrix. Meeker and Lu Valle (1995) have previously proposed that CAF failure is best represented by two competing reactions -- the formation of a copper chloride corrosion compound (now identified as Cu2(OH)3Cl) and the formation of innocuous trapped chlorine compounds. Since no evidence of any trapped chloride compounds has been found, we propose that the formation of CAF is best represented by a single non-reversible reaction. For coupons processed with a high bromide-containing flux, bromide containing CAF was created and characterized using transmission electron microscopy (TEM) to be Cu2(OH)3Br. In addition, a copper-containing compound was formed in the polymer matrix and characterized using XPS as CuBr. An electrochemical mechanism for the formation of bromide-containing CAF has been proposed based on the XPS data.

Caputo, Antonio

311

Pattern formation in the geosciences  

PubMed Central

Pattern formation is a natural property of nonlinear and non-equilibrium dynamical systems. Geophysical examples of such systems span practically all observable length scales, from rhythmic banding of chemical species within a single mineral crystal, to the morphology of cusps and spits along hundreds of kilometres of coastlines. This article briefly introduces the general principles of pattern formation and argues how they can be applied to open problems in the Earth sciences. Particular examples are then discussed, which summarize the contents of the rest of this Theme Issue.

Goehring, Lucas

2013-01-01

312

Adaptive Optics and Star Formation  

NASA Astrophysics Data System (ADS)

In this contribution I will briefly review the growing impact adaptive optics is having on the field of star formation. The volume of interesting scientific papers published to date is by far too large for this paper to be even close to be a complete review (but see Ménard, Lai & Dumas 2004). Instead, I will present a few recent results to show topics in star formation where adaptive optics has had a significant impact lately. These selected topics include the search and characterisation of accretion disks, the surveys to measure the binary fraction among the various pre-main sequence populations, and the search for low-mass and substellar companions.

Ménard, François

313

Star formation and extinct radioactivities  

NASA Technical Reports Server (NTRS)

An assessment is made of the evidence for the existence of now-extinct radioactivities in primitive solar system material, giving attention to implications for the early stages of sun and solar system formation. The characteristics of possible disturbances in dense molecular clouds which can initiate the formation of cloud cores is discussed, with emphasis on these disturbances able to generate fresh radioactivities. A one-solar mass red giant star on the asymptotic giant branch appears to have been the best candidate to account for the short-lived extinct radioactivities in the early solar system.

Cameron, A. G. W.

1984-01-01

314

Star formation across galactic environments  

NASA Astrophysics Data System (ADS)

I present here parallel investigations of star formation in typical and extreme galaxies. The typical galaxies are selected to be free of active galactic nuclei (AGN), while the extreme galaxies host quasars (the most luminous class of AGN). These two environments are each insightful in their own way; quasars are among the most violent objects in the universe, literally reshaping their host galaxies, while my sample of AGN-free star-forming galaxies ranges from systems larger than the Milky Way to small galaxies which are forming stars at unsustainably high rates. The current paradigm of galaxy formation and evolution suggests that extreme circumstances are key stepping stones in the assembly of galaxies like our Milky Way. To test this paradigm and fully explore its ramifications, this dual approach is needed. My sample of AGN-free galaxies is drawn from the KPNO International Spectroscopic Survey. This Halpha-selected, volume-limited survey was designed to detect star-forming galaxies without a bias toward continuum luminosity. This type of selection ensures that this sample is not biased toward galaxies that are large or nearby. My work studies the KISS galaxies in the mid- and far-infrared using photometry from the IRAC and MIPS instruments aboard the Spitzer Space Telescope. These infrared bands are particularly interesting for star formation studies because the ultraviolet light from young stars is reprocessed into thermal emission in the far-infrared (24mum MIPS) by dust and into vibrational transitions features in the mid-infrared (8.0mum IRAC) by polycyclic aromatic hydrocarbons (PAHs). The work I present here examines the efficiencies of PAH and thermal dust emission as tracers of star-formation rates over a wide range of galactic stellar masses. I find that the efficiency of PAH as a star-formation tracer varies with galactic stellar mass, while thermal dust has a highly variable efficiency that does not systematically depend on galactic stellar mass. Complementing this study of normal star-forming galaxies, my study of quasar host galaxies utilizes narrow- and medium-band images of eight Palomar-Green (PG) quasars from the WFPC2 and NICMOS instruments aboard the Hubble Space Telescope. Using images of a point-spread function (PSF) star in the same filters, I subtract the PSF of the quasar from each of the target images. The residual light images clearly show the host galaxies of the respective quasars. The narrow-band images were chosen to be centered on the Hbeta, [O II ], [O III], and Paalpha emission lines, allowing the use of line ratios and luminosities to create extinction and star formation maps. Additionally, I utilize the line-ratio maps to distinguish AGN-powered line emission from star formation powered line emission with line-diagnostic diagrams. I find star formation in each of the eight quasar host galaxies in my study. The bulk star-formation rates are lower than expected, suggesting that quasar host galaxies may be dynamically more advanced than previously believed. Seven of the eight quasar host galaxies in this study have higher-than-typical mass-specific star-formation rates. Additionally, I see evidence of shocked gas, supporting the hypotheses presented in earlier works that suggest that AGN activity quenches star formation in its host galaxy by disrupting its gas reservoir.

Young, Jason

315

Massive star formation: new results  

NASA Astrophysics Data System (ADS)

In the past year several new observations with important implications for massive star formation (MSF) have been obtained. Among these were the detection of UC H II region precursor candidates at 350 ?m and the discovery of many hard X-ray point sources in the Orion and W3 MSF region. These observations are summarized below.

Churchwell, Ed

316

Study of Yttrium Hydroxide Formation.  

National Technical Information Service (NTIS)

A study was made of yttrium hydroxide formation in sulphuric acid, chlorine and nitric acid solutions by means of the solubility method, measurement of pH and equilibrium solution electroconductivity, apparent residue volume, and x-ray phase analysis. It ...

I. M. Polyashkov N. V. Mal'kevich I. A. Grishin

1973-01-01

317

The Theory of Planetary Formation  

NSDL National Science Digital Library

This website offers an audio of a lecture on the theory of planetary formation. There is also an option to use a viewgraph if you do not have real audio player. The site also provides a detailed written summary of the audio lecture.

Cassen, Patrick

2010-08-06

318

Coalition Formation Among Autonomous Agents  

Microsoft Academic Search

Coalitions of agents can work more effectively than individual agents in many multi-agent settings. Determining which coalitions should form (i.e., what agents should work together) is a difficult problem that is typically solved by some kind of centralised planner. As the number of agents grows, however, reliance on a central authority becomes increasingly impractical. This paper formalises the coalition formation

Steven P. Ketchpel

1993-01-01

319

Amyloid Beta Mediates Memory Formation  

ERIC Educational Resources Information Center

The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

Garcia-Osta, Ana; Alberini, Cristina M.

2009-01-01

320

Geometric Cooperative Control of Formations.  

National Technical Information Service (NTIS)

Robots in a team are modeled as particles which obey simple, second order dynamics. The whole team can be viewed as a deformable body with changing shape and orientation. Jacobi shape theory is applied to model such a formation. The configuration space of...

F. Zhang

2004-01-01

321

Formation of Clastic Sedimentary Rocks  

NSDL National Science Digital Library

This animation traces the formation of sedimentary rock. It starts at a beach environment where sea water minerals cement sand grains together. The animation concludes with a real microscopic image of sandstone showing both mineral grains and cement. The animation can be paused and rewound to stress important points.

2010-01-01

322

Montezuma Formation of Costa Rica  

Microsoft Academic Search

The Montezuma Formation of the Nicoya Peninsula is one of the better known Neogene stratigraphic units of the Pacific side of Costa Rica. Past workers have reported its age to be Miocene-Pliocene or Miocene-Quaternary, and its environment of deposition to be inner shelf. The planktonic foraminiferal record of the unit in the type locality, however, places it firmly in the

W. H. McKee; B. K. Sen Gupta

1985-01-01

323

Technology Enhanced Distributive Formative Evaluation  

ERIC Educational Resources Information Center

Quality assurance in instructional development demands an exhaustive formative evaluation effort and applied testing. Unfortunately, this process is expensive and requires large numbers of user testers with characteristics similar to the intended audience. This article presents a procedure for increasing the efficiency of quality assurance efforts…

Moore, David Richard

2008-01-01

324

CCF: The Common Communication Format.  

ERIC Educational Resources Information Center

The purpose of the Common Communication Format (CCF) is to provide a detailed and structured method for recording a number of mandatory and optional data elements in a computer-readable bibliographic record for exchange purposes between two or more computer-based systems. However, it can also be useful within non-computerized bibliographic…

Simmons, Peter, Ed.; Hopkinson, Alan, Ed.

325

Electrodeposit Formation in Solid Electrolytes  

Microsoft Academic Search

Devices based on polarity-dependent switching in solid electrolytes show great promise as next generation memory and perhaps even logic devices. These elements operate by the formation of robust but reversible electrodeposited conducting pathways which can be grown and dissolved at low voltage and current. Although such devices have been well characterized, little has been presented on the exact growth mechanism

Michael N. Kozicki; Cynthia Ratnakumar; Maria Mitkova

2006-01-01

326

Pattern formation during fracture dissolution  

Microsoft Academic Search

A number of experimental and numerical studies of dissolution in fractured and porous rocks have established that the evolving topography of the pore space depends strongly on the fluid flow and mineral dissolution rates. Remarkably, there exists a wide parameter range in which positive feedback between fluid transport and mineral dissolution leads to the spontaneous formation of pronounced channels, frequently

P. Szymczak; T. Ladd

2009-01-01

327

Stereotype Formation: Biased by Association  

Microsoft Academic Search

We propose that biases in attitude and stereotype formation might arise as a result of learned differences in the extent to which social groups have previously been predictive of behavioral or physical properties. Experiments 1 and 2 demonstrate that differences in the experienced predictiveness of groups with respect to evaluatively neutral information influence the extent to which participants later form

Mike E. Le Pelley; Stian J. Reimers; Guglielmo Calvini; Russell Spears; Tom Beesley; Robin A. Murphy

2010-01-01

328

Formation of artificial ionospheric ducts  

Microsoft Academic Search

It is well known that strong electron heating by a powerful HF-facility can lead to the formation of electron and ion density perturbations that stretch along the magnetic field line. Those density perturbations can serve as ducts for ELF waves, both of natural and artificial origin. This paper presents the first experimental evidence of plasma modifications associated with ion outflows

G. M. Milikh; K. Papadopoulos; H. Shroff; C. L. Chang; T. Wallace; E. V. Mishin; M. Parrot; J. J. Berthelier

2008-01-01

329

Formation control with collision avoidance  

Microsoft Academic Search

We present a formation flight control strategy featuring a collision avoidance scheme. The control algorithm is based on a Sliding Mode controller. The controller sliding surfaces account for aircraft maneuvering limitations, restricting the required velocities to a feasible set. Further, the relative position between vehicles affects the sliding surfaces shape, enabling collision avoidance. The control method derivation is based on

Ricardo Bencatel; Mariam Faied; Joao Sousa; Anouck R. Girard

2011-01-01

330

A Bluetooth scatternet formation algorithm  

Microsoft Academic Search

A Bluetooth ad hoc network can be formed by interconnecting piconets into scatternets. The constraints and properties of Bluetooth scatternets present special challenges in forming an ad hoc network efficiently. We present and analyse a new randomized distributed algorithm for Bluetooth scatternet formation. We prove that our algorithm achieves O(log n) time complexity and O(n) message complexity. We show that:

Ching Law; Kai-Yeung Siu

2001-01-01

331

Distributed Bluetooth scatternet formation algorithm  

Microsoft Academic Search

Bluetooth is a short range communication technology in which devices communicate in a master-slave fashion within a piconet. Several piconets interconnect via gateway devices to form a scatternet. This paper introduces a greedy approach to scatternet tree and mesh formation which tries to minimize the number of piconets at each iterative step. The protocol is distributed, rapidly converging and incurs

Vikas P. Verma; Amit A. Chandak

2003-01-01

332

Formative Assessment: A Cybernetic Viewpoint  

ERIC Educational Resources Information Center

This paper considers alternative assessment, feedback and cybernetics. For more than 30 years, debates about the bi-polarity of formative and summative assessment have served as surrogates for discussions about the workings of the mind, the social implications of assessment and, as important, the role of instruction in the advancement of learning.…

Roos, Bertil; Hamilton, David

2005-01-01

333

Pattern formation outside of equilibrium  

Microsoft Academic Search

A comprehensive review of spatiotemporal pattern formation in systems driven away from equilibrium is presented, with emphasis on comparisons between theory and quantitative experiments. Examples include patterns in hydrodynamic systems such as thermal convection in pure fluids and binary mixtures, Taylor-Couette flow, parametric-wave instabilities, as well as patterns in solidification fronts, nonlinear optics, oscillatory chemical reactions and excitable biological media.

M. C. Cross; P. C. Hohenberg

1993-01-01

334

Biofilm Formation by Candida dubliniensis  

Microsoft Academic Search

Candida dubliniensis is an opportunistic yeast closely related to Candida albicans that has been recently implicated in oropharyngeal candidiasis in human immunodeficiency virus-infected patients. Most manifes- tations of candidiasis are associated with biofilm formation, with cells in biofilms displaying properties dramatically different from free-living cells grown under normal laboratory conditions. Here, we report on the development of in vitro models

GORDON RAMAGE; KACY VANDE WALLE; BRIAN L. WICKES

2001-01-01

335

Formation of the outer planets  

Microsoft Academic Search

A discussion is given of a number of physical processes which were probably important during the formation of the outer planets if these formed from a gaseous solar nebula in which magnetic effects were not important. Arguments are given that large-scale gravitational instabilities in the solar nebula did not occur. Qualitative consideration is given to the conditions in which dynamical

A. G. W. Cameron

1973-01-01

336

Brain gangliosides and memory formation  

Microsoft Academic Search

It is generally accepted that the process of molecular facilitation of neuronal circuits by means of stabilization of synaptic contacts represents the structural basis for memory formation. At the distinct zone of synaptic contact the following basic events occur: alterations of the electrical field strength at the outer surface of synaptic membranes, conformational changes of membrane-bound functional proteins (ion channels,

Hinrich Rahmann

1995-01-01

337

Mechanisms of polymeric film formation.  

PubMed

Polymeric films are applied to solid dosage forms for decorative, protective, and functional purposes. These films are generally applied by a spray atomization process, where the polymer is sprayed onto the solid substrate. The mechanism by which films are formed is dependent on whether the polymer is in the dissolved or dispersed state. For solutions, film formation occurs as the solvent evaporates, since the polymer chains are intimately mixed. Film formation from polymeric dispersions, however, requires the coalescence of individual polymer spheres and interpenetration of the polymer chains. Films prepared from polymeric dispersions exhibit a minimum film forming temperature and processing conditions must exceed this temperature in order to form the film. In addition, these systems generally require post-coating storage in temperature and humidity controlled environments to ensure complete polymer coalescence. Incomplete coalescence can lead to significant changes in drug release over time. This review article highlights the basic science principles involved in film formation from both polymeric solutions and dispersions and the variables that influence these film formation processes. PMID:23305867

Felton, Linda A

2013-12-01

338

Vertical formations demand unique treatments  

Microsoft Academic Search

In the US midcontinent area, major thrust faults trap large quantities of hydrocarbons in the down-thrown fault block. As exploration of these thrust fault structures continues, the application of extended reach and horizontal well bores will increase. Formations in deep structures are apt to have lower porosity and permeability than the currently developed thrust faults and thus, require fracture stimulation.

1996-01-01

339

VLBI Data Interchange Format (VDIF).  

National Technical Information Service (NTIS)

One important outcome of the 7th International e-VLBI Workshop in Shanghai in June 2008 was the creation of a task force to study and recommend a universal VLBI data format that is suitable for both on-the-wire e-VLBI data transfer, as well as direct disk...

A. Whitney C. Phillips M. Kettenis M. Sekido

2010-01-01

340

Chevrons formation in laminar erosion  

NASA Astrophysics Data System (ADS)

When eroded by laminar free-surface flows, granular substrates may generate a rich variety of natural patterns. Among them are dunes, similar to the ones observed by Charru and Hinch in a Couette cell (Charru F, Hinch EJ ; Ripple formation on a particle bed sheared by a viscous liquid. Part 1. Steady flow ; JOURNAL OF FLUID MECHANICS 550: 111-121 MAR 10 2006). Chevron-shaped instabilities as those found on the sea-shore, can also be observed, sometimes in competition against dunes formation. These were first pointed out by Daerr et al. when pulling a plate covered with granular material out of a bath of water (Daerr A, Lee P, Lanuza J, et al. ; Erosion patterns in a sediment layer ; PHYSICAL REVIEW E 67 (6): Art. No. 065201 Part 2 JUN 2003). Both instabilities can grow in laminar open-channel flows, an experimental set-up which is more easily controlled. The mechanisms leading to the formation of these patterns are investigated and compared. Whereas dunes formation requires vertical inertia effects, we show that chevrons may result from the non-linear evolution of bars instability, which may grow even in purely viscous flows.

Devauchelle, Olivier; Josserand, Christophe; Lagree, Pierre-Yves; Zaleski, Stephane; Nguyen, Khanh-Dang; Malverti, Luce; Lajeunesse, Eric

2007-11-01

341

Stereotype Formation: Biased by Association  

ERIC Educational Resources Information Center

We propose that biases in attitude and stereotype formation might arise as a result of learned differences in the extent to which social groups have previously been predictive of behavioral or physical properties. Experiments 1 and 2 demonstrate that differences in the experienced predictiveness of groups with respect to evaluatively neutral…

Le Pelley, Mike E.; Reimers, Stian J.; Calvini, Guglielmo; Spears, Russell; Beesley, Tom; Murphy, Robin A.

2010-01-01

342

Pattern Formation in Active Fluids  

Microsoft Academic Search

We discuss pattern formation in active fluids in which active stress is regulated by diffusing molecular components. Nonhomogeneous active stress profiles create patterns of flow which transport stress regulators by advection. Our work is motivated by the dynamics of the actomyosin cell cortex in which biochemical pathways regulate active stress. We present a mechanism in which a single diffusing species

Justin S. Bois; Frank Jülicher; Stephan W. Grill

2011-01-01

343

Heteronuclear Diatomic Molecular Orbital Formation  

NSDL National Science Digital Library

Here is a set of movies that demonstrates heteronuclear diatomic molecular orbital formation. The orbitals start at a distance where there is little or no interatomic interaction and move to the appropriate bond distance. Orbital phase is shown by the different colors.

344

Memory formation by neuronal synchronization.  

PubMed

Cognitive functions not only depend on the localization of neural activity, but also on the precise temporal pattern of activity in neural assemblies. Synchronization of action potential discharges provides a link between large-scale EEG recordings and cellular plasticity mechanisms. Here, we focus on the role of neuronal synchronization in different frequency domains for the subsequent stages of memory formation. Recent EEG studies suggest that synchronized neural activity in the gamma frequency range (around 30-100 Hz) plays a functional role for the formation of declarative long-term memories in humans. On the cellular level, gamma synchronization between hippocampal and parahippocampal regions may induce LTP in the CA3 region of the hippocampus. In order to encode spatial locations or sequences of multiple items and to guarantee a defined temporal order of memory processing, synchronization in the gamma frequency range has to be accompanied by a stimulus-locked phase reset of ongoing theta oscillations. Simultaneous gamma- and theta-dependent plasticity leads to complex learning rules required for realistic declarative memory formation. Subsequently, consolidation of declarative memories may occur via replay of newly acquired patterns in so-called sharp wave-ripple complexes, predominantly during slow-wave sleep. These irregular bursts induce longer lasting forms of synaptic plasticity in output regions of the hippocampus and in the neocortex. In summary, synchronization of neural assemblies in different frequency ranges induces specific forms of cellular plasticity during subsequent stages of memory formation. PMID:16545463

Axmacher, Nikolai; Mormann, Florian; Fernández, Guillen; Elger, Christian E; Fell, Juergen

2006-08-30

345

Biofilm Formation by Pneumocystis spp.? †  

PubMed Central

Pneumocystis spp. can cause a lethal pneumonia in hosts with debilitated immune systems. The manner in which these fungal infections spread throughout the lung, the life cycles of the organisms, and their strategies used for survival within the mammalian host are largely unknown, due in part to the lack of a continuous cultivation method. Biofilm formation is one strategy used by microbes for protection against environmental assaults, for communication and differentiation, and as foci for dissemination. We posited that the attachment and growth of Pneumocystis within the lung alveoli is akin to biofilm formation. An in vitro system comprised of insert wells suspended in multiwell plates containing supplemented RPMI 1640 medium supported biofilm formation by P. carinii (from rat) and P. murina (from mouse).Dramatic morphological changes accompanied the transition to a biofilm. Cyst and trophic forms became highly refractile and produced branching formations that anastomosed into large macroscopic clusters that spread across the insert. Confocal microscopy revealed stacking of viable organisms enmeshed in concanavalin A-staining extracellular matrix. Biofilms matured over a 3-week time period and could be passaged. These passaged organisms were able to cause infection in immunosuppressed rodents. Biofilm formation was inhibited by farnesol, a quorum-sensing molecule in Candida spp., suggesting that a similar communication system may be operational in the Pneumocystis biofilms. Intense staining with a monoclonal antibody to the major surface glycoproteins and an increase in (1,3)-?-d-glucan content suggest that these components contributed to the refractile properties. Identification of this biofilm process provides a tractable in vitro system that should fundamentally advance the study of Pneumocystis.

Cushion, Melanie T.; Collins, Margaret S.; Linke, Michael J.

2009-01-01

346

Dust Formation in Brown Dwarfs  

NASA Astrophysics Data System (ADS)

Brown Dwarfs provide favorable conditions for the gas-solid phase transition since in its atmosphere low temperatures with high densities are combined. Observations of unexpectedly weak molecular absorption bands indicate the existence of dust in their atmospheres. Considering stability arguments, high temperature compounds like CaTiO3, Fe2-xSixO4 or Al2O_3 are expected to form first. Another argument for the formation of heterogeneous dust is given by the wide variety of molecular species of comparable abundances in an oxygen-rich gas. The description of the formation of such heterogeneous particles, however, is still a matter of debate since the nominal molecules are only present in negligible amounts or even completely absent in the gas phase. Furthermore, the formation of solid particles has to proceed via the formation of seed particles which is followed by the growth towards macroscopic sizes. Thereby, a large supersaturation has to be achieved which results in a considerable gap between typical nucleation temperatures and the sublimation temperatures of plane solid. Promising astrophysical seed candidates are (TiO2N and (Fe)N clusters which appears in appropriate amounts in oxygen-rich gases; Fe seeds maybe even more favorable in the densest regions of the atmospheres (nH > 1019cm-3). In this presentation, the efficiency of nucleation and the stability of solid compounds are examined for a typical atmosphere of a Brown Dwarf in comparison to M dwarfs and Jupiter-like planets. We additionally present first results of numerical calculations for Brown Dwarf atmospheres including a detailed time-dependent, phase non-equilibrium description of the formation of core-mantel grains. Dust properties like the amount and the sizes of the solid particles are thereby a result of the calculation.

Lüttke, M.; Helling, Ch.; John, M.; Jeong, K. S.; Woitke, P.; Sedlmayr, E.

347

Sedimentary pyrite formation: An update  

NASA Astrophysics Data System (ADS)

Sedimentary pyrite formation during early diagenesis is a major process for controlling the oxygen level of the atmosphere and the sulfate concentration in seawater over geologic time. The amount of pyrite that may form in a sediment is limited by the rates of supply of decomposable organic matter, dissolved sulfate, and reactive detrital iron minerals. Organic matter appears to be the major control on pyrite formation in normal (non-euxinic) terrigenous marine sediments where dissolved sulfate and iron minerals are abundant. By contrast, pyrite formation in non-marine, freshwater sediments is severely limited by low concentrations of sulfate and this characteristic can be used to distinguish ancient organic-rich fresh water shales from marine shales. Under marine euxinic conditions sufficient H 2S is produced that the dominant control on pyrite formation is the availability of reactive iron minerals. Calculations, based on a sulfur isotope model, indicate that over Phanerozoic time the worldwide average organic carbon-to-pyrite sulfur ratio of sedimentary rocks has varied considerably. High C/S ratios during Permo-Carboniferous time can be explained by a shift of major organic deposition from the oceans to the land which resulted in the formation of vast coal swamps at that time. Low C/S ratios, compared to today, during the early Paleozoic can be explained in terms of a greater abundance of euxinic basins combined with deposition of a more reactive type of organic matter in the remaining oxygenated portions of the ocean. The latter could have been due to lower oceanic oxygen levels and/or a lack of transportation of refractory terrestrial organic matter to the marine environment due to the absence of vascular land plants at that time.

Berner, Robert A.

1984-04-01

348

Method of fracturing a geological formation  

DOEpatents

An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

1990-01-01

349

Formation of Molecular Clouds and Initial Conditions of Star Formation  

NASA Astrophysics Data System (ADS)

Using three-dimensional magnetohydrodynamic simulations, including the effects of radiative cool- ing/heating, chemical reactions, self-gravity and thermal conduction, we investigate the formation of molecular clouds in the multi-phase interstellar medium. We consider the formation of molecular clouds due to accretion of HI clouds as suggested by recent observations. Our simulations show that the initial HI medium is piled up behind the shock waves induced by accretion flows. Since the accreting medium is highly inhomogeneous as a consequence of thermal instability, a newly formed molecular cloud becomes very turbulent owing to the development of the Richtmyer-Meshkov instability. The kinetic energy of the turbulence dominates the thermal, magnetic, and gravitational energies. However, the kinetic energy measured using CO-fraction-weighted density is comparable to the other energies, once the CO molecules are sufficiently formed as a result of UV shielding. This suggests that the true kinetic energy of turbulence in molecular clouds as a whole can be much larger than the kinetic energy of turbulence estimated by using line widths of molecular emission. We find that dense clumps in the molecular cloud show the following evolution: the typical plasma beta of the clumps is roughly constant; the size-?locity dispersion relation follows Larson's law, irrespective of the density; and the clumps evolve into magnetically supercritical cores by clump-clump collisions. These statistical properties would represent the initial conditions of star formation.

Inoue, Tsuyoshi

2013-07-01

350

Laser beam pulse formatting method  

DOEpatents

A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

1994-08-09

351

Laser beam pulse formatting method  

DOEpatents

A method for formatting a laser beam pulse (20) using one or more delay loops (10). The delay loops (10) have a partially reflective beam splitter (12) and a plurality of highly reflective mirrors (14) arranged such that the laser beam pulse (20) enters into the delay loop (10) through the beam splitter (12) and circulates therein along a delay loop length (24) defined by the mirrors (14). As the laser beam pulse (20) circulates within the delay loop (10) a portion thereof is emitted upon each completed circuit when the laser beam pulse (20) strikes the beam splitter (12). The laser beam pulse (20) is thereby formatted into a plurality of sub-pulses (50, 52, 54 and 56). The delay loops (10) are used in combination to produce complex waveforms by combining the sub-pulses (50, 52, 54 and 56) using additive waveform synthesis.

Daly, Thomas P. (Livermore, CA); Moses, Edward I. (Livermore, CA); Patterson, Ralph W. (Livermore, CA); Sawicki, Richard H. (Danville, CA)

1994-01-01

352

Rapid gas hydrate formation process  

DOEpatents

The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

2013-01-15

353

Exospore formation in Methylosinus trichosporium.  

PubMed Central

Formation of exospores in Methylosinus trichosporium was examined by electron microscopy; serial sectioning was used to visualize the shape and location of the developing exospore in relation to the vegetative cell. The initial stage was the formation of a budlike enlargement on one end of the vegetative cell. The enlargement was surrounded by the exospore capsule, and the cell wall was continuous around both the cell and the developing exospore. A constriction occurred in the area where the budlike structure was attached to the vegetative cell, and the constriction continued to form until the immature exospore was detached from the vegetative cell. The cup-shaped immature exospore was surrounded by the exospore capsule, which appeared to hold the exospore close to the vegetative cell. After separation from the vegetative cell, the immature exospore developed further by forming the exospore wall and by becoming spherical. Images

Titus, J A; Reed, W M; Pfister, R M; Dugan, P R

1982-01-01

354

The dynamics of city formation*  

PubMed Central

This paper examines city formation in a country whose urban population is growing steadily over time, with new cities required to accommodate this growth. In contrast to most of the literature there is immobility of housing and urban infrastructure, and investment in these assets is taken on the basis of forward-looking behavior. In the presence of these fixed assets cities form sequentially, without the population swings in existing cities that arise in current models, but with swings in house rents. Equilibrium city size, absent government, may be larger or smaller than is efficient, depending on how urban externalities vary with population. Efficient formation of cities with internalization of externalities involves local government intervention and borrowing to finance development. The paper explores the institutions required for successful local government intervention.

Henderson, J. Vernon; Venables, Anthony J.

2013-01-01

355

Engineering biofilm formation and dispersal  

PubMed Central

Anywhere water is in the liquid state, bacteria will exist as biofilms, which are complex communities of cells cemented together. Although frequently associated with disease and biofouling, biofilms are also important for engineering applications, such as bioremediation, biocatalysis and microbial fuel cells. Here we review approaches to alter genetic circuits and cell signaling toward controlling biofilm formation, and emphasize utilizing these tools for engineering applications. Based on a better understanding of the genetic basis of biofilm formation, we find that biofilms may be controlled by manipulating extracellular signals and that they may be dispersed using conserved intracellular signals and regulators. Biofilms could also be formed at specific locations where they might be engineered to make chemicals or treat human disease.

Wood, Thomas K.; Hong, Seok Hoon; Ma, Qun

2011-01-01

356

Cycling Behavior and Memory Formation  

PubMed Central

Circadian research has spent considerable effort in the determining clock output pathways, including identifying both physiological and behavioral processes that demonstrate significant time-of-day variation. Memory formation and consolidation represent notable processes shaped by endogenous circadian oscillators. To date, very few studies on memory mechanisms have considered potential confounding effects of time-of-day and the organism’s innate activity cycles (e.g., nocturnal, diurnal, or crepuscular). The following studies highlight recent work describing this interactive role of circadian rhythms and memory formation, and were presented at a minisymposium at the 2009 annual meeting of the Society for Neuroscience. The studies illustrate these time-of-day observations in a variety of behavioral paradigms and model organisms, including olfactory avoidance conditioning in Drosophila, long-term sensitization in Aplysia, active-avoidance conditioning in Zebrafish, and classical fear conditioning in rodents, suggesting that the circadian influence on memory behavior is highly conserved across species. Evidence also exists for a conserved mechanistic relationship between specific cycling molecules and memory formation, and the extent to which proper circadian cycling of these molecules is necessary for optimal cognitive performance. Studies describe the involvement of the core clock gene period, as well as vasoactive intestinal peptide, melatonin, and the cAMP/MAPK (cAMP/mitogen-activated protein kinase) cascade. Finally, studies in humans describe evidence for alterations in cognitive performance based on an interaction between sleep–wake homeostasis and the internal circadian clock. Conservation of a functional relationship between circadian rhythms with learning and memory formation across species provides a critical framework for future analysis of molecular mechanisms underlying complex behavior.

Gerstner, Jason R.; Lyons, Lisa C.; Wright, Kenneth P.; Loh, Dawn H.; Rawashdeh, Oliver; Eckel-Mahan, Kristin L.; Roman, Gregg W.

2014-01-01

357

Union formation in fragile families  

Microsoft Academic Search

In this article, we use data from a new longitudinal survey—the Fragile Families and Child Wellbeing Study—to examine union\\u000a formation among unmarried parents who have just had a child together. We used multinomial logistic regression to estimate\\u000a the effects of economic, cultural\\/interpersonal, and other factors on whether (relative to having no romantic relationship)\\u000a parents are romantically involved and living apart,

Marcia Carlson; Sara Mclanahan; Paula England

2004-01-01

358

Biofilm formation on oral piercings  

Microsoft Academic Search

Summary  PURPOSE: Biofilms on oral piercings might serve as a bacterial reservoir in the host and lead to bacteraemia and even septic\\u000a complications. The use of piercing materials less susceptible to biofilm accumulation could contribute to alleviation of problems.\\u000a The present study aimed to assess biofilm formation on four commercially available, surface characterized piercing materials\\u000a in vitro (polytetrafluoroethylene, titanium, stainless steel,

Ines Kapferer; Christoph Steiner; Ulrike Beier; Natalia Schiefermeier; Markus Nagl; Frederik Klauser

2010-01-01

359

Crystal sedimentation and stone formation  

Microsoft Academic Search

Mechanisms of crystal collision being the first step of aggregation (AGN) were analyzed for calcium oxalate monohydrate (COM)\\u000a directly produced in urine. COM was produced by oxalate titration in urine of seven healthy men, in solutions of urinary macromolecules\\u000a and in buffered distilled water (control). Crystal formation and sedimentation were followed by a spectrophotometer and analyzed\\u000a by scanning electron microscopy.

Johannes Markus Baumann; Beat Affolter; Rolf Meyer

2010-01-01

360

Molecular mechanisms of memory formation  

Microsoft Academic Search

Studies with neonate chicks, trained on a passive avoidance task, suggest that at least two shorter-term memory stages precede\\u000a long-term, protein synthesis-dependent memory consolidation. Posttetanic neuronal hyperpolarization arising from two distinct\\u000a mechanisms is postulated to underlie formation of these two early memory stages. Maintenance of the second of these stages\\u000a may involve a prolonged period of hyperpolarization brought about by

K. T. Ng; M. E. Gibbs; S. F. Crowe; G. L. Sedman; F. Hua; W. Zhao; B. O'Dowd; N. Rickard; C. L. Gibbs; E. Syková; J. Svoboda; P. Jendelová

1991-01-01

361

Contrail formation in aircraft wakes  

Microsoft Academic Search

The process of the formation and early evolution of a condensation trail (`contrail') in the near field of an aircraft wake was numerically studied by means of a mixed Eulerian\\/Lagrangian two-phase flow approach. Large-eddy simulations were used for the carrier phase, while, for the dispersed phase, a Lagrangian particle tracking method was used, coupled with a microphysics model to account

Roberto Paoli; Jerome Hélie; Thierry Poinsot

2004-01-01

362

Central control of bone formation  

Microsoft Academic Search

Vertebrates constantly remodel bone to maintain a constant bone mass. Bone remodeling comprises two phases: bone resorption\\u000a by the osteoclasts followed by bone formation by the osteoblasts. Although the prevailing view about the control of bone remodeling\\u000a is that it is an autocrine\\/paracrine phenomenon, the bone resorption arm of bone remodeling is under a tight endocrine control.\\u000a To date little

Shu Takeda; Gerard Karsenty

2001-01-01

363

Membrane adhesion and domain formation  

Microsoft Academic Search

We review theoretical results for the adhesion-induced phase behavior of biomembranes. The focus is on models in which the membranes are represented as discretized elastic sheets with embedded adhesion molecules. We present several mechanism that lead to the formation of domains during adhesion, and discuss the time-dependent evolution of domain patterns obtained in Monte-Carlo simulations. The simulated pattern dynamics has

Thomas R. Weikl; Reinhard Lipowsky

2007-01-01

364

Seminoe 3, a tidally influenced lowstand wedge and its relationships with subjacent highstand and overlying transgressive deposits, Haystack Mountains Formation, Cretaceous Western Interior, Wyoming (USA)  

NASA Astrophysics Data System (ADS)

The Campanian Haystack Mountains Formation (Wyoming, USA) consists of a series of deltaic/estuarine and shoreface sandstone tongues stacked in basinward-stepping units separated by shale intervals. Regional analysis indicates that the tongues have a distinctive two-tiered architecture: (a) a lower sandbody with bioturbated and hummocky strata of wave-dominated shoreface origin; and (b) an erosively based upper unit with bioturbated to tabular cross-bedded sandstones. This study focuses on a single tongue, Seminoe 3, which crops out in a 40 km long continuous dip-oriented exposure. In its landward reaches (westwards) the tongue consists of a thin unit of offshore-transitional to lower shoreface deposits. In the central part of the exposure it becomes thicker and consists of a cross-bedded wedge which truncates the shoreface deposits and pinches out by downlap eastwards onto a thick, westward migrating, shoreface lithosome (spit), probably developed on the margin of a wave-dominated delta. Detailed correlation and mapping of bounding surfaces indicate that the shoreface and spit lithosomes were deposited in a forced regressive mode during falling relative sea-level. The overlying cross-bedded lithosome, is a lowstand wedge which prograded over an incised topography created during the early stage of sea-level lowstand. A large embayment is suggested to have developed during the highstand/forced regressive phase, with shoreline and spit deposits prograding from opposing sides. Significant erosion and truncation occurred during the lowstand phase, as well as a basinward shift of facies onto the shelf and the pre-existing spit deposits. In the early stage of transgression the embayment was drowned, and a tide-dominated, estuarine environment was established. The resulting cross-bedded wedge displays an aggrading to prograding stacking pattern of parasequences with the uppermost portion exhibiting a retrogradational pattern, as a consequence of the reworking operated by the transgression.

Mellere, Donatella

1996-06-01

365

Pattern formation in optical resonators  

NASA Astrophysics Data System (ADS)

We review pattern formation in optical resonators. The emphasis is on 'particle-like' structures such as vortices or spatial solitons. On the one hand, similarities impose themselves with other fields of physics (condensed matter, phase transitions, particle physics, fluds/super fluids). On the other hand the feedback is led by the resonator mirrors to bi- and multi-stability of the spatial field structure, which is the basic ingredient for optical information processing. The spatial dimension or the 'parallelism' is the strength of optics compared to electronics (and will have to be employed to fully use the advantages optics offers in information processing). But even in the 'serial' processing tasks of telecoms (e.g. information buffering) spatial resonator solitons can do better than the schemes proposed so far—including 'slow light'. Pattern formation in optical resonators will likely be the key to brain-like information processing like cognition, learning and association; to complement the precise but limited algorithmic capabilities of electronic processing. But even in the short term it will be useful for solving serial optical processing problems. The prospects for technical uses of pattern formation in resonators are one motivation for this research. The fundamental similarities with other fields of physics, on the other hand, inspire transfer of concepts between fields; something that has always proven fruitful for gaining deeper insights or for solving technical problems.

Weiss, C. O.; Larionova, Ye

2007-02-01

366

Clumpy disc and bulge formation  

NASA Astrophysics Data System (ADS)

We present a set of hydrodynamical/N-body controlled simulations of isolated gas-rich galaxies that self-consistently include supernova (SN) feedback and a detailed chemical evolution model, both tested in cosmological simulations. The initial conditions are motivated by the observed star-forming galaxies at z ˜ 2-3. We find that the presence of a multiphase interstellar media in our models promotes the growth of disc instability favouring the formation of clumps which, in general, are not easily disrupted on time-scales compared to the migration time. We show that stellar clumps migrate towards the central region and contribute to form a classical-like bulge with a Sérsic index, n > 2. Our physically motivated SN feedback has a mild influence on clump survival and evolution, partially limiting the mass growth of clumps as the energy released per SN event is increased, with the consequent flattening of the bulge profile. This regulation does not prevent the building of a classical-like bulge even for the most energetic feedback tested. Our SN feedback model is able to establish self-regulated star formation, producing mass-loaded outflows and stellar age spreads comparable to observations. We find that the bulge formation by clumps may coexist with other channels of bulge assembly such as bars and mergers. Our results suggest that galactic bulges could be interpreted as composite systems with structural components and stellar populations storing archaeological information of the dynamical history of their galaxy.

Perez, Josefa; Valenzuela, Octavio; Tissera, Patricia B.; Michel-Dansac, Leo

2013-11-01

367

Stellar Metallicity and Planet Formation  

NASA Astrophysics Data System (ADS)

We describe results from two independent analyses of the [Fe/H] abundance of stars in two separate planet search programs. For the Keck, AAT, and Lick (KAL) planet search program, we determined stellar parameters spectroscopically. Results for the CORALIE and KAL both show a similar steep increase in the fraction of stars with known planets as stellar [Fe/H] increase. This planet metallicity correlation is a key observational constraint on the formation and evolution of giant planets. We rule out changes in velocity precision as the cause of the correlation. By comparing stars with different convection zone depths (along and off the main-sequence), we rule out chemical enrichment by accretion as the origin of the correlation. Most known planets have migrated inwards since formation. The end point of migration does not depend on stellar [Fe/H], but it is still possible that migration occurs only above some metallicity threshold. The planet-metallicity correlation is consistent with core-accretion scenarios of giant planet formation.

Valenti, J.; Fischer, D.

2008-04-01

368

Rock Cycle: Environments of Formation  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Rocks SciPack. It provides an in-depth exploration of the conditions and environment required during the formation of igneous, sedimentary, and metamorphic rocks. Igneous rock forms from the cooling and crystallization of magma. Sometimes the magma reaches Earth's surface and cools quickly; sometimes it does not reach the surface and thus cools slowly. Rocks at Earth's surface are subjected to processes of weathering and erosion, producing sediments as they are broken down. Sedimentary rock is formed when sediments are buried and solidified through various processes. Sedimentary rock buried deep enough may be transformed into metamorphic rock or melted down to magma. Rock formed deep within the crust (either igneous or metamorphic) may be forced up again to become land surface and even mountains by the forces that drive the motion of Earth's plates. Subsequently, this new rock too will erode. Learning Outcomes:� Realize that different rocks have specific origins, and that they are the product of any number of processes.� Identify the processes through which igneous, sedimentary, and metamorphic rock form.� Explain the role of intermediary materials such as sediment and magma in the formation of different kinds of rock.� Provide an overarching description of the steps in the rock cycle, the formation of sedimentary rock, the re-forming of rock by heat and pressure, and the process by which re-formed rock can return to the surface.

National Science Teachers Association (NSTA)

2006-11-01

369

Formation of Outer Planets: Overview  

NASA Technical Reports Server (NTRS)

An overview of current theories of planetary formation, with emphasis on giant planets is presented. The most detailed models are based upon observation of our own Solar System and of young stars and their environments. Terrestrial planets are believe to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. According to the prevailing core instability model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the growing giant cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk disspates. The primary questions regarding the core instability model is whether planets with small cores can accrete gaseous enveloples within the lifetimes of gaseous protoplanetary disks. The main alternative giant planet formation model is the disk instability model, in which gaseous planets form directly via gravitational instabilities within protoplanetary disks. Formation of giant planets via gas instability has never been demonstrated for realistic disk conditions. Moreover, this model has difficulty explaining the supersolar abundances of heavy elements in Jupiter and Saturn, and it does not explain the orgin of planets like Uranus and Neptune.

Lissauer, Jack

2003-01-01

370

SCALE FORMATION IN CHRYSOPHYCEAN ALGAE  

PubMed Central

The cell wall of the marine chrysophycean alga Pleurochrysis scherfellii is composed of distinct wall fragments embedded in a gelatinous mass. The latter is a polysaccharide of pectic character which is rich in galactose and ribose. These wall fragments are identified as scales. They have been isolated and purified from the vegetative mother cell walls after zoospore formation. Their ultrastructure is described in an electron microscope study combining sectioning, freeze-etch, and negative staining techniques. The scales consist of a layer of concentrically arranged microfibrils (ribbons with cross-sections of 12 to 25 x 25 to 40 A) and underlying radial fibrils of similar dimensions. Such a network-plate is densely coated with particles which are assumed to be identical to the pectic component. The microfibrils are resistant to strong alkaline treatment and have been identified as cellulose by different methods, including sugar analysis after total hydrolysis, proton resonance spectroscopical examination (NMR spectroscopy) of the benzoylated product, and diverse histochemical tests. The formation and secretion of the scales can be followed along the maturing Golgi cisternae starting from a pronounced dilated "polymerization center" as a completely intracisternal process which ends in the exocytotic extrusion of the scales. The scales reveal the very same ultrastructure within the Golgi cisternae as they do in the cell wall. The present finding represents the first evidence on cellulose formation by the Golgi apparatus and is discussed in relation to a basic scheme for cellulose synthesis in plant cells in general.

Brown, R. Malcolm; Franke, Werner W.; Kleinig, Hans; Falk, Heinz; Sitte, Peter

1970-01-01

371

Modeling of Dynamic FRC Formation  

NASA Astrophysics Data System (ADS)

We have developed a 2-D resistive MHD code, Lamy Ridge, to simulate the entire FRC formation process in Tri Alpha's C2 device, including initial formation, translation, merging and settling into equilibrium. Two FRC's can be created simultaneously, and then translated toward each other so that they merge into a single FRC. The code couples the external circuits around the formation tubes to the partially ionized plasma inside. Plasma and neutral gas are treated as two fluids. Dynamic and energetic equations, which take into account ionization and charge exchange, are solved in a time advance manner. The geometric shape of the vessel is specified by a set of inputs that defines the boundaries, which are handled by a cut-cell algorithm in the code. Multiple external circuits and field coils can be easily added, removed or relocated through individual inputs. The design of the code is modular and flexible so that it can be applied to future devices. The results of the code are in reasonable agreement with experimental measurements on the C2 device.

Mok, Yung; Barnes, Dan; Dettrick, Sean

2010-11-01

372

Supernova Feedback in Galaxy Formation  

NASA Astrophysics Data System (ADS)

The hierarchical model of galaxy formation is known to suffer from the ``over-cooling'' problem: the high efficiency of radiative cooling results in too much baryonic matter in a condensed phase (namely, cold gas or stars) when compared to observations. A solution proposed by many authors (see Springel & Hernquist 2003; Fujita et al. 2004; Rasera & Teyssier 2005) is feedback due to supernova (SN) driven winds or active galactic nuclei. Modeling SN feedback by direct injection of thermal energy usually turns out to be inefficient in galaxy-scale simulations, due to the quasi-instantaneous radiation of the SN energy. To avoid this effect, we have developed a new method to incorporate SN feedback in cosmological simulations: using temporary test particles, we reproduce explicitly a local Sedov blast wave solution in the gas distribution. We have performed several self-consistent runs of isolated Navarro, Frenk, & White (1996, hereafter NFW) halos with radiative cooling, star formation, SN feedback and metal enrichment using the adaptive mesh refinement code RAMSES (Teyssier 2002). We have explored the influence of SN feedback on the formation and the evolution of galaxies with different masses. We have studied the efficiency of the resulting galactic winds, as a function of the mass of the parent halo.

Dubois, Y.; Teyssier, R.

2008-06-01

373

Uranium favorability of part of the Raleigh Quadrangle, North Carolina  

Microsoft Academic Search

Part of the Raleigh, North Carolina, 1° by 2° quadrangle was evaluated to identify geologic environments favorable for uranium. Tabular sandstone deposits may occur in the Triassic basins where the Cumnock Formation interfingers with the Sanford Formation. The uranium deposits may have formed where humic and fulvic acids were expelled from lacustrine sediments to form tabular humate deposits. Later, uranium

R. T. Chew; C. M. Hacke

1982-01-01

374

Formate auxotroph of Methanobacterium thermoautotrophicum Marburg.  

PubMed Central

A formate-requiring auxotroph of Methanobacterium thermoautotrophicum Marburg was isolated after hydroxylamine mutagenesis and bacitracin selection. The requirement for formate is unique and specific; combined pools of other volatile fatty acids, amino acids, vitamins, and nitrogen bases did not substitute for formate. Compared with those of the wild type, cell extracts of the formate auxotroph were deficient in formate dehydrogenase activity, but cells of all of the strains examined catalyzed a formate-carbon dioxide exchange activity. All of the strains examined took up a small amount (200 to 260 mumol/liter) of formate (3 mM) added to medium. The results of the study of this novel auxotroph indicate a role for formate in biosynthetic reactions in this methanogen. Moreover, because methanogenesis from H2-CO2 is not impaired in the mutant, free formate is not an intermediate in the reduction of CO2 to CH4.

Tanner, R S; McInerney, M J; Nagle, D P

1989-01-01

375

Outlook: Testing Planet Formation Theories  

NASA Astrophysics Data System (ADS)

The discovery of the first planetary companion to a solar-type star by Mayor and Queloz (1995) launched the extrasolar planetary systems era. Observational and theoretical progress in this area has been made at a breathtaking pace since 1995, as evidenced by this workshop. We now have a large and growing sample of extrasolar gas giant planets with which to test our theories of their formation and evolution. The two competing theories for the formation of gas giant planets, core accretion and disk instability, appear to have testable predictions: (i) Core accretion seems to require exceptionally long-lived disks, implying that gas giants should be somewhat rare, while disk instability can occur in even the shortest-lived disk, implying that gas giants should be abundant. The ongoing census of gas giants by the spectroscopic search programs will determine the frequency of gas giants on Jupiter-like orbits within the next decade. (ii) Core accretion takes millions of years to form gas giants, while disk instability forms gaseous protoplanets in thousands of years. Determining the epoch of gas giant planet formation by searching for astrometric wobbles indicative of gas giant companions around young stars with a range of ages (˜ 0.1 Myr to ˜ 10 Myr) should be possible with the Space Interferometry Mission (SIM). (iii) Core accretion would seem to be bolstered by a higher ratio of dust to gas, whereas disk instability occurs equally well for a range of dust opacities. Determining whether a high primordial metallicity is necessary for gas giant planet formation can be accomplished by spectroscopic and astrometric searches for gas giants around metal-poor stars. Eventually, ice giant planets will be detectable as well. If ice giants are found to be much more frequent that gas giants, this may imply that core accretion occurs, but usually fails to form a gas giant. Terrestrial planets will be detected through photometry by Kepler and Eddington, astrometry by SIM, and imaging by Terrestrial Planet Finder and Darwin. Ultimately these detections will clarify the process of Earth formation by collisional accumulation, the only contending theory.

Boss, A. P.

376

Formation mechanisms of metal colloids  

NASA Astrophysics Data System (ADS)

Highly dispersed uniform metallic particles are widely used in various areas of technology and medicine and are likely to be incorporated into many other applications in the future. It is commonly accepted that size, shape and composition of the particles represent critical factors in most applications. Thus, understanding the mechanisms of formation of metal particles and the ways to control the physical (e.g. shape, size) and chemical (e.g. composition) properties is of great importance. In the current research, the formation of uniform silver spheres is investigated experimentally. The parameters that influence the formation of silver particles when concentrated iso-ascorbic acid and silver-polyamine complex solutions are rapidly mixed were studied in the absence of dispersants. We found that by varying the nature of the amine, temperature, concentration of reactants, silver/amine molar ratio, and the nature of the silver salt, the size of the resulting silver particles can be varied in a wide range (0.08--1.5 microm). The silver particles were formed by aggregation of nanosize subunits as substantiated by both electron microscopy and X-ray diffraction techniques and by the vivid rapid color changes during the chemical precipitation process. From the practical standpoint, the goal of this research was to prepare well dispersed spherical silver particles having a relatively smooth surface and a diameter of about 1 microm to satisfy the demands of the current electronic materials market. A two stage particle growth model previously developed to explain the narrow size distribution occurring in synthesis of gold spheres was applied to the present experimental system, and the parameters that control the size distribution characteristics were identified. The kinetic parameter required to match the final particle size was found to be in agreement with the one used previously in modeling formation of gold spheres, suggesting that similar kinetics governs the aggregation process. Furthermore, the two-stage particle growth model was used to account for the effects of solvent viscosity and temperature on the particle properties, particularly their size. As an application of the above mentioned study, the aggregation process that led to the formation of large silver spheres was used to deposit in a controlled manner layers of silver and other metals (Ni, Au) onto various metallic and non-metallic substrates. In the final section of this thesis methods to form nanosized primary particle strictly through diffusional growth are described. The highly crystalline metallic particles of various sizes and composition prepared provide performance characteristics that are complementary to the polycrystalline metallic particles described in the preceding sections.

Halaciuga, Ionel

377

Formation of the hurricane eye  

NASA Astrophysics Data System (ADS)

This dissertation consists of three distinct studies which investigate aspects of eye formation. The first study reviews eye phenomenon in a variety of vortices ranging from simple vortices to the menagerie of geophysical vortices, emphasizing similarities and differences to the eyes formed in hurricanes. The hurricane eye is found to be a paradoxical structure imposed by conservation of angular momentum and the boundaries of the vortex. A comprehensive definition for hurricane eye formation is proposed and various eye formation mechanisms are summarized. The next study presents a simple theoretical argument to isolate the conditions under which a tropical cyclone can rapidly develop a warm-core thermal structure and subsequently approach a steady state. The theoretical argument is based on the balanced vortex model and, in particular, on the associated transverse circulation equation and the geopotential tendency equation. The transverse circulation and the temperature tendency in a tropical vortex depend not only on the diabatic forcing, but also on the spatial distributions of the static stability, the baroclinity, and the inertial stability. The vortex response to diabatic heating depends critically on whether the heating occurs in the low inertial stability region outside the radius of maximum wind or in the high inertial stability region inside the radius of maximum wind. This result suggests that rapid intensification is favored for storms which have at least some of the eyewall convection inside the radius of maximum wind. The development of an eye partially removes diabatic heating from the high inertial stability region of the storm center, yet rapid intensification may continue if the eyewall heating continues to become more efficient. As the warm core matures and static stability increases over the inner core, conditions there become less favorable for deep upright convection and the storm tends to approach a steady state. The final study characterizes the kinematic and thermodynamic changes that occur before, during, and after the initial eye formations of a broad set of Atlantic tropical cyclones. To obtain the requisite structure and intensity parameters, a new data set has been synthesized from the Vortex Data Messages transmitted by routine aircraft reconnaissance from 1989--2008. Intensity ranges are determined for the times when the eye/eyewall structure first appears in aircraft radar and infrared satellite imagery. The mean intensity at which an eye is first observed in both aircraft or satellite imagery is found to be 58 kt, somewhat lower than reported in previous studies. Changes about the time of eye formation are examined for intensity, the radius of maximum winds, the minimum Rossby radius of deformation, eye temperature and dew point temperature depression. Storms are found to intensify most rapidly near the time of eye formation, especially when a persistent eye is observed in infrared satellite imagery. Many storms which are forming eyes are found to undergo a substantial and rapid contraction in the radius of maximum winds during the 24-h period before the eye is observed; once the eye is present, this contraction slows or ceases. Strong warming at lower levels (850 or 700 hPa) of the eye is not observed to correlate well with the time in which the eye is first observed. Finally, observations suggest that the dynamical heating efficiency of the resulting eyewall increases even as the physical scale of the efficient heating region decreases. This allows the storm to continue intensifying even though the total inner core diabatic heating may decrease. The answer to why some storms fail to form eyes may shed light on whether eye formation is a stochastic process involving constructive and destructive mesoscale interactions---or whether it is a manifold attractor of the system sometimes stymied by an unfavorable environment.

Vigh, Jonathan L.

378

Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections through the Central Appalachian Basin.  

National Technical Information Service (NTIS)

The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and s...

R. D. Crangle

2007-01-01

379

14 CFR 302.603 - Contents of complaint or request for determination.  

Code of Federal Regulations, 2010 CFR

...versions, or in such other format as may be specified by notice in the Federal Register: Microsoft Word (or RTF), Word Perfect, Ami Pro, Microsoft Excel, Lotus 123, Quattro Pro, or ASCII tab-delineated files. Parties should...

2010-01-01

380

Total Petroleum Hydrocarbons (TPH): ToxFAQs  

MedlinePLUS

... Some PDF files may be electronic conversions from paper copy or other electronic ASCII text files. This ... format errors. Users are referred to the original paper copy of the toxicological profile for the official ...

381

Science and Technology Pocket Data Book: 1994  

NSF Publications Database

... & Technology Pocket Data Book: 1994 - ASCII text files (.htm) - - Word Perfect 5.1 file (.wp5) - ... different formats. NSF 94-323 Contents, All text, & List of other Publications The National R&D ...

382

Basin scale evolution of formation waters: a diagenetic and formation water study of the Triassic Chaunoy Formation, Paris Basin  

Microsoft Academic Search

Formation waters and their movements within basins are commonly attributed with responsibility for patterns of cementation and porosity-loss within reservoirs and aquifers. It is thus important to understand when and how waters move in the subsurface. We have studied the evolution and movement of formation water in the Triassic Chaunoy Formation of the Paris Basin, NW Europe to define the

R. H Worden; M. L Coleman; J-M Matray

1999-01-01

383

The formation of cluster galaxies  

NASA Astrophysics Data System (ADS)

In this work I sought to understand the formation and evolution of galaxies. Specifically, I studied three key aspects of galaxy formation: star formation, mass assembly, and structural evolution. Past research has shown that the formation of a galaxy is strongly coupled to its local environment (i.e. the local galaxy density). Therefore, I studied the evolution of cluster galaxies because clusters are the highest density environments that exist in the universe. In turn, the observational results found herein form a foundation upon which to test theories of galaxy formation in the densest environments. I used the latest sample of galaxy clusters from the Bootes region to measure the near-infrared luminosity function (NIR LF) of cluster galaxies from 0 < z < 2 and estimate the primary epoch of star formation for massive cluster galaxies. I found that massive cluster galaxies formed the bulk of their stars at zf ˜ 2.5, that they evolved passively at z ? 1.3, and that they deviated from passive evolution at higher redshifts. This latter observation suggested that massive cluster galaxies were actively assembling their final stellar masses at z > 1.3. I used deeper IRAC imaging to study the NIR LF of high redshift cluster galaxies (1 < z < 1.5) with focus on the properties of faint (i.e. low mass) galaxies. I found no evidence for evolution of the LF for low mass cluster galaxies out to the highest redshifts studied, which suggested that the cluster galaxy population was in place at high redshift. Finally, I calculated the evolution of the size-mass relationship (SMR) of cluster galaxies as a function of morphology for the high redshift cluster sample. I found that apparent evolution of the SMR can be partially explained by the progenitor bias, but that there was a missing population of large, massive cluster galaxies. These galaxies were either be accreted by clusters at lower redshifts, or the cluster galaxy population underwent size-evolution to account for their presence at low redshift. I developed two new programs to aid in my research as well as future research in this field. I created EzGal, a program which extracts observables (magnitudes, k-corrections, stellar masses, mass-to-light ratios, etc...) from standard stellar population synthesis (SPS) models. This simplified comparisons of observations to many different model sets, and simplified comparison of different model sets to each other. I used EzGal to quantitatively compare various model sets and estimate SPS model uncertainty, and recovered the well known result that SPS models agree best in the optical for old stellar populations, but disagree substantially for intermediate age stellar populations in the NIR. The latter uncertainty was caused by the presence of thermally pulsating AGB stars, which are poorly understood observationally but contribute substantially to the NIR light of a stellar population. I also created the Python Galaxy Fitter (PyGFit), a program which measures PSF matched photometry from crowded imaging with disparate PSFs and resolutions. This enabled accurate measurement of spectral energy distributions (SEDs) in crowded cluster fields.

Mancone, Conor L.

384

On-Going Galaxy Formation  

NASA Astrophysics Data System (ADS)

We investigate the process of galaxy formation as can be observed in the only currently forming galaxies - the so-called Tidal Dwarf Galaxies, hereafter TDGs - through observations of the molecular gas detected via its CO (Carbon Monoxide) emission. These objects are formed of material torn off of the outer parts of a spiral disk due to tidal forces in a collision between two massive galaxies. Molecular gas is a key element in the galaxy formation process, providing the link between a cloud of gas and a bona fide galaxy. We have detected CO in 8 TDGs (Braine, Lisenfeld, Duc and Leon, 2000: Nature 403, 867; Braine, Duc, Lisenfeld, Charmandaris, Vallejo, Leon and Brinks: 2001, A&A 378, 51), with an overall detection rate of 80%, showing that molecular gas is abundant in TDGs, up to a few 108 M ?. The CO emission coincides both spatially and kinematically with the HI emission, indicating that the molecular gas forms from the atomic hydrogen where the HI column density is high. A possible trend of more evolved TDGs having greater molecular gas masses is observed, in accord with the transformation of HI into H2. Although TDGs share many of the properties of small irregulars, their CO luminosity is much greater (factor ˜ 100) than that of standard dwarf galaxies of comparable luminosity. This is most likely a consequence of the higher metallicity (?sim 1/3 solar) of TDGs which makes CO a good tracer of molecular gas. This allows us to study star formation in environments ordinarily inaccessible due to the extreme difficulty of measuring the molecular gas mass. The star formation efficiency, measured by the CO luminosity per H? flux, is the same in TDGs and full-sized spirals. CO is likely the best tracer of the dynamics of these objects because some fraction of the HI near the TDGs may be part of the tidal tail and not bound to the TDG. Although uncertainties are large for individual objects, as the geometry is unknown, our sample is now of eight detected objects and we find that the ‘dynamical’ masses of TDGs, estimated from the CO line widths, seem not to be greater than the ‘visible’ masses (HI + H2 + a stellar component). Although higher spatial resolution CO (and HI) observations would help reduce the uncertainties, we find that TDGs require no dark matter, which would make them the only galaxy-sized systems where this is the case. Dark matter in spirals should then be in a halo and not a rotating disk. Most dwarf galaxies are dark matter-rich, implying that they are not of tidal origin. We provide strong evidence that TDGs are self-gravitating entities, implying that we are witnessing the ensemble of processes in galaxy formation: concentration of large amounts of gas in a bound object, condensation of the gas, which is atomic at this point, to form molecular gas and the subsequent star formation from the dense molecular component.

Braine, Jonathan; Duc, P.-A.; Lisenfeld, U.; Charmandaris, V.; Vallejo, O.; Leon, S.; Brinks, E.

2002-07-01

385

Micelle formation of sodium hyodeoxycholate.  

PubMed

Sodium hyodeoxycholate (NaHDC) is the main component of hog bile salts, which play a role in the absorption of sparingly soluble materials in the intestinal solution. The biosurfactant has an amphiphilic molecular structure, similar to that of ursodeoxycholate from bear gallbladder. Micelle formation from hyodeoxycholate was studied at 308.2K using pyrene fluorescence probe to determine critical micelle concentrations (cmc) at various NaCl concentrations. The change in the fluorescence spectrum peak ratios with NaHDC concentration indicated two steps for bile salt aggregation. The first step was the formation of small micelles (cmc) at 5mM, and the second step was the formation of stable aggregates at 14 mM in aqueous solution. The aggregation of hyodeoxycholate, analyzed using the stepwise association model, was found to grow its aggregation number from 4 to 7 with increasing concentration. The aggregation number in aqueous solution was also confirmed by the static light scattering method. The average measured aggregation number of the micelles was 6.7. The micellar size was relatively small as measured by either method, but it was covered by general aggregation number of human bile salts. The degree of counterion binding to the micelles, determined using a sodium ion-selective electrode, was ca. 0.5 for the NaHDC micelles. This value was relatively high among typical bile salts. Moreover, the solubilization capacity of the NaHDC micelles was assessed using cholesterol. It became clear that NaHDC micelles hardly solubilized cholesterol compared to typical human bile salts. The maximum solubilization by NaHDC was equivalent only to that by sodium ursodeoxycholate. PMID:23665117

Matsuoka, Keisuke; Takagi, Kaede; Honda, Chikako

2013-01-01

386

Sequential star formation in Cassiopeia  

NASA Astrophysics Data System (ADS)

Massive stars (M ? 9 M_{?}) are usually formed in OB associations, consisting of one or more not very massive open clusters and a halo of scattered young stars. The study of these open clusters can provide clues about how stellar formation proceeds from the parent molecular clouds. We present first results on a project to understand sequential star formation mechanisms in OB associations. We have chosen associations Cas OB4, Cas OB5 and Cas OB7, close to the Cassiopeia constellation, at l = 110°-125°. Previous determinations of their distance provided very similar values for them all, and placed them on the Perseus Arm. This study aims at improved distance and age determinations using new spectroscopic observations and existing photometry. The goal is to investigate whether the clusters in Cas OB4, Cas OB5 and Cas OB7 are separate entities or can be enclosed in a global common OB association. If associated,we will check for evidence of induced star formation. We preselected about 100 stars from 12 clusters, based on photometric criteria. Long-slit spectra were taken with the Intermediate Dispersion Spectrograph at the Isaac Newton Telescope (2.5 m), located in La Palma's Observatorio del Roque de los Muchachos. We used the R632V grating, to achieve a spectral coverage between 3500 Å and 5500 Å and spectral resolution of 0.90 Å px^{-1}. The observed spectra have been used to determine the spectral type and luminosity class of the sample stars. The spectral classification yields the stellar properties (from calibrations), and will enable the reconstruction of the HR-diagram. We present in this poster newly discovered B-type stars in two selected clusters.

Velasco, S.; García, M.; Negueruela, I.

2013-05-01

387

Microbial Formation of Manganese Oxides  

PubMed Central

Microbial manganese oxidation was demonstrated at high Mn2+ concentrations (5 g/liter) in bacterial cultures in the presence of a microalga. The structure of the oxide produced varied depending on the bacterial strain and mode of culture. A nonaxenic, acid-tolerant microalga, a Chlamydomonas sp., was found to mediate formation of manganite (?-MnOOH). Bacteria isolated from associations with crude cultures of this alga grown in aerated bioreactors formed disordered ?-MnO2 from Mn2+ at concentrations of 5 g/liter over 1 month, yielding 3.3 g of a semipure oxide per liter. All algal-bacterial cultures removed Mn2+ from solution, but only those with the highest removal rates formed an insoluble oxide. While the alga was an essential component of the reaction, a Pseudomonas sp. was found to be primarily responsible for the formation of a manganese precipitate. Medium components—algal biomass and urea—showed optima at 5.7 and 10 g/liters, respectively. The scaled-up culture (50 times) gave a yield of 22.3 g (53 mg/liter/day from a 15-liter culture) of semipure disordered ?-MnO2, identified by X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy, and had a manganese oxide O/Mn ratio of 1.92. The Mn(IV) content in the oxide was low (30.5%) compared with that of mined or chemically formed ?-MnO2 (ca. 50%). The shortfall in the bacterial oxide manganese content was due to biological and inorganic contaminants. FTIR spectroscopy, transmission electron microscopy, and electron diffraction studies have identified manganite as a likely intermediate product in the formation of disordered ?-MnO2.

Greene, Anthony C.; Madgwick, John C.

1991-01-01

388

Digital Formats for Content Reproductions  

NSDL National Science Digital Library

This small document, though designed mainly to aid entrants in the Library of Congress/Ameritech Digital Library Competition, is also an updated inside look at the procedures used to create the digital images in LOC's National Digital Library Program, particularly its famous American Memory digital collection. The report details the standards used by the Library in digitization of images, text, maps, sound files, and movies. While these are not necessarily universal standards, few institutions or individuals have more experience than LOC in these endeavors. Digital Formats will be of great value to anyone interested in digitizing library collections.

389

Petrophysical evaluation of subterranean formations  

DOEpatents

Methods and systems are provided for evaluating petrophysical properties of subterranean formations and comprehensively evaluating hydrate presence through a combination of computer-implemented log modeling and analysis. Certain embodiments include the steps of running a number of logging tools in a wellbore to obtain a variety of wellbore data and logs, and evaluating and modeling the log data to ascertain various petrophysical properties. Examples of suitable logging techniques that may be used in combination with the present invention include, but are not limited to, sonic logs, electrical resistivity logs, gamma ray logs, neutron porosity logs, density logs, NRM logs, or any combination or subset thereof.

Klein, James D; Schoderbek, David A; Mailloux, Jason M

2013-05-28

390

The formation of pyridine haemochromogen  

PubMed Central

1. Titration of haem with pyridine in alkaline media of low ionic strength yields a true pyridine haemochromogen, compound III, at very low concentrations of pyridine. 2. Graphical analysis of this titration gives the first spectrophotometric evidence for a dimeric haem. 3. Compound III is unstable and tends to aggregate to a second compound, compound II, whose formation is enhanced under those conditions favourable to hydrophobic bonding. 4. At higher concentrations of pyridine, compound II is dispersed to yield the classical pyridine haemochromogen, compound I, whose spectral properties are essentially those of pyridine haemochromogen in a non-aqueous medium.

Gallagher, W. A.; Elliott, W. B.

1965-01-01

391

The formation of interstellar jets  

NASA Technical Reports Server (NTRS)

The formation of interstellar jets by convergence of supersonic conical flows and the further dynamical evolution of these jets are investigated theoretically by means of numerical simulations. The results are presented in extensive graphs and characterized in detail. Strong radiative cooling is shown to result in jets with Mach numbers 2.5-29 propagating to lengths 50-100 times their original widths, with condensation of swept-up interstellar matter at Mach 5 or greater. The characteristics of so-called molecular outflows are well reproduced by the simulations of low-Mach-number and quasi-adiabatic jets.

Tenorio-Tagle, G.; Canto, J.; Rozyczka, M.

1988-01-01

392

Transcriptional control of adipocyte formation  

PubMed Central

A detailed understanding of the processes governing adipose tissue formation will be instrumental in combating the obesity epidemic. Much progress has been made in the last two decades in defining transcriptional events controlling the differentiation of mesenchymal stem cells into adipocytes. A complex network of transcription factors and cell-cycle regulators, in concert with specific transcriptional coactivators and corepressors, respond to extracellular stimuli to activate or repress adipocyte differentiation. This review summarizes advances in this field, which constitute a framework for potential antiobesity strategies.

Farmer, Stephen R.

2007-01-01

393

Formation Flying and Deformable Instruments  

SciTech Connect

Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

Rio, Yvon [CEA/IRFU/Sap, CEA Saclay, 91191 Gif sur Yvette (France)

2009-05-11

394

Wormhole formation in dissolving fractures  

NASA Astrophysics Data System (ADS)

We investigate the dissolution of artificial fractures with three-dimensional, pore-scale numerical simulations. The fluid velocity in the fracture space was determined from a lattice Boltzmann method, and a stochastic solver was used for the transport of dissolved species. Numerical simulations were used to study conditions under which long conduits (wormholes) form in an initially rough but spatially homogeneous fracture. The effects of flow rate, mineral dissolution rate, and geometrical properties of the fracture were investigated, and the optimal conditions for wormhole formation were determined.

Szymczak, P.; Ladd, A. J. C.

2009-06-01

395

Carbonate formation in Marslike environments  

NASA Technical Reports Server (NTRS)

A finely ground basaltic rock subjected to Marslike temperatures, atmospheric pressures and compositions and UV-rich illumination has provided a simulation system for studying carbonate growth in the Martian regolith. Growth rates of about 10 to the 12th or 13th power molecules per cu cm per sec are observed with or without the presence of liquid-phase water. The role of UV illumination in the photochemistry of water, a process which influences chemical alteration activity, is discussed. The study suggests that carbonate formation is an important aspect of Martian chemical weathering and that it provides a major chemical reservoir for outgassed carbon dioxide.

Booth, M. C.; Kieffer, H. H.

1978-01-01

396

Zonal flow as pattern formation  

SciTech Connect

Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows, and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the wavelength of the zonal flows is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.

Parker, Jeffrey B.; Krommes, John A. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2013-10-15

397

Electrochemical formation of field emitters  

DOEpatents

Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area.

Bernhardt, Anthony F. (Berkeley, CA)

1999-01-01

398

Branch formation during organ development  

PubMed Central

Invertebrates and vertebrates use branching morphogenesis to build epithelial trees to maximize the surface area of organs within a given volume. Several molecular regulators of branching have recently been discovered, a number of which are conserved across different organs and species. Signals that control branching at the cellular and tissue levels are also starting to emerge, and are rapidly unveiling the physical nature of branch development. Here we discuss the molecular, cellular and physical processes that govern branch formation and highlight the major outstanding questions in the field.

Gjorevski, Nikolce; Nelson, Celeste M.

2010-01-01

399

Common Biometric Exchange Formats Framework (CBEFF).  

National Technical Information Service (NTIS)

This specification, the Common Biometric Exchange Formats Framework, is an augmented and revised version of the original CBEFF, the Common Biometric Exchange File Format, published in January 2001 as NISTIR 6529. This version, NISTIR 6529-A, was developed...

B. Struif C. J. Tilton F. L. Podio J. S. Dunn L. Reinert

2004-01-01

400

Negative ion formation processes: A general review  

SciTech Connect

The principal negative ion formation processes will be briefly reviewed. Primary emphasis will be placed on the more efficient and universal processes of charge transfer and secondary ion formation through non-thermodynamic surface ionization. 86 refs., 20 figs.

Alton, G.D.

1990-01-01

401

External Resource: The Formation of the Moon  

NSDL National Science Digital Library

This Windows to The Universe webpage explores the formation of the Moon. Topics: Moon surface, planetismals, Period of Late Heavy Bombardment, Moon core and mantle, lunar Maria, collisional ejection theory, capture theory, co-formation theory.

1900-01-01

402

Gas-Phase Infrared; JCAMP Format  

National Institute of Standards and Technology Data Gateway

SRD 35 NIST/EPA Gas-Phase Infrared; JCAMP Format (PC database for purchase)   This data collection contains 5,228 infrared spectra in the JCAMP-DX (Joint Committee for Atomic and Molecular Physical Data "Data Exchange") format.

403

SAR polar format implementation with MATLAB.  

SciTech Connect

Traditional polar format image formation for Synthetic Aperture Radar (SAR) requires a large amount of processing power and memory in order to accomplish in real-time. These requirements can thus eliminate the possible usage of interpreted language environments such as MATLAB. However, with trapezoidal aperture phase history collection and changes to the traditional polar format algorithm, certain optimizations make MATLAB a possible tool for image formation. Thus, this document's purpose is two-fold. The first outlines a change to the existing Polar Format MATLAB implementation utilizing the Chirp Z-Transform that improves performance and memory usage achieving near realtime results for smaller apertures. The second is the addition of two new possible image formation options that perform a more traditional interpolation style image formation. These options allow the continued exploration of possible interpolation methods for image formation and some preliminary results comparing image quality are given.

Martin, Grant D.; Doerry, Armin Walter

2005-11-01

404

Complex Formation between Dimethyl Methylphosphonate and Hexafluoroisopropanol.  

National Technical Information Service (NTIS)

A solvent/water partitioning method was used to measure the complex formation between dimethyl methylphosphonate (DMMP) and hexafluoroisopropanol (HFIP). The highest formation constant was obtained when n-hexane was used as the partitioning solvent. Other...

D. C. Leggett

1990-01-01

405

XML Format for SESAME and LEOS  

SciTech Connect

The objective of this document is to describe the XML format used by LLNL and LANL to represent the equation-of-state and related material information in the LEOS and SESAME data libraries. The primary purpose of this document is to describe a specific XML format for representing EOS data that is tailored to the nature of the underlying data and is amenable to conversion to both legacy SESAME and LEOS binary formats. The secondary purpose is to describe an XML format that lends itself to a 'natural' representation in a binary file format of the SESAME, pdb or hdf5 form so that this format and related tools can be used for the rapid and efficient development and implementation of prototype data structures. This document describes the XML format only. A working knowledge of LEOS and SESAME formats is assumed.

Durrenberger, J K; Neely, J R; Sterne, P A

2009-04-29

406

Formation of the terrestrial planets from planetesimals  

NASA Technical Reports Server (NTRS)

Formation of the terrestrial planets from planetesimals is discussed. The following subject areas are covered: (1) formation of the original planetesimals; (2) growth of planetesimals into planetary embryos; and (3) growth of runaway planetary embryos into terrestrial planets.

Wetherill, George W.

1991-01-01

407

Formative Assessment - Part I and Part II  

NSDL National Science Digital Library

In these podcasts, Kate Garrison, Manager of Products and services for Professional Development with Measured Progress, describes formative assessment as a verb, not a noun - a process whereby students and teachers maintain ongoing conversation about learning, formative assessment is key to student achievement. Kate Garrison debunks 5 myths about formative assessment in the first of this 2-part discussion. In the second, she discusses the culture of formative assessment.

2009-06-04

408

Treating nahcolite containing formations and saline zones  

DOEpatents

A method for treating a nahcolite containing subsurface formation includes removing water from a saline zone in or near the formation. The removed water is heated using a steam and electricity cogeneration facility. The heated water is provided to the nahcolite containing formation. A fluid is produced from the nahcolite containing formation. The fluid includes at least some dissolved nahcolite. At least some of the fluid is provided to the saline zone.

Vinegar, Harold J

2013-06-11

409

Galaxy interactions and star formation: Results of a survey of global H-alpha emission in spiral galaxies in 8 clusters  

NASA Technical Reports Server (NTRS)

Kennicutt and Kent (1983) have shown that the global H alpha emission from a spiral galaxy is an indicator of the formation rate of massive stars. Moss, Whittle and Irwin (1988) have surveyed two clusters (Abell 347 and 1367) for galaxies with H alpha emission using a high dispersion objective prism technique. The purpose of the survey is to investigate environmental effects on star formation in spiral galaxies, and in particular to ascertain whether star formation is enhanced in cluster spirals. Approximately 20 percent of CGCG galaxies were detected in emission. Two plates of excellent quality were obtained for each of the two clusters, and galaxies were only identified to have emission if this was detected on both plates of a plate pair. In this way, plate flaws and other spurious identifications of emission could be rejected, and weak emission confirmed. The results of this survey have been discussed by Moss (1987). The detected galaxies are of types SO-a and later. The frequency with which galaxies are detected in emission increases towards later morphological type as expected (cf. Kennicutt and Kent 1983). There is no evidence of any dependence of the frequency of detected emission on the absolute magnitude of the galaxy (cf. Moss and Whittle 1990), but there is a strong correlation between a disturbed morphological appearance of the galaxy and the detection of emission. Furthermore it is found that the emission is more centrally concentrated in those galaxies which show a disturbed morphology. It may be noted that the objective prism plate gives a spectrum of a 400 A region around rest wavelength H alpha, but superposed on this is the H alpha emission from the galaxy which, because the light is essentially monochromatic, results in a true two-dimensional image of the H alpha distribution. The visual appearance of the emission on the prism plates was classified according to its diffuseness on a 5 point scale (very diffuse, diffuse, intermediate, compact, and very compact). In tabular form, the relation is shown between this classification and a morphologically disturbed appearance for the galaxy.

Moss, C.

1990-01-01

410

Lower Eocene alluvial paleosols (Willwood Formation, Northwest Wyoming, U.S.A.) and their significance for paleoecology, paleoclimatology, and basin analysis  

USGS Publications Warehouse

The lower Eocene Willwood Formation of northwest Wyoming is a 700 m thick accumulation of alluvial floodplain and channel mudstones and sandstones, nearly all of which show paleopedogenic modifications. Pedogenesis of Willwood sandstones is indicated by taproot and vertebrate and invertebrate bioturbation, early local cementation by calcium carbonate, and thin illuviation cutans on clastic grains. Pedogenesis in Willwood mudstones is indicated by plant bioturbation, insect and other invertebrate burrow casts and lebensspuren; free iron, aluminum, and manganese mobilization, including hydromorphic gleying; sesquioxide and calcareous glaebule formation in lower parts of the solum; presence of clay-rich and organic carbon-rich zones; and well differentiated epipedons and albic and spodic horizons. Probable A horizons are also locally well developed. Occurrence of variegated paleosol units in thick floodplain mudstone deposits and their association with thin, lenticular, and unconnected fluvial sandstones in the Willwood Formation of the central and southeast Bighorn Basin suggest that these soils formed during times of rapid sediment accumulation. The tabular geometry and lateral persistence of soil units as well as the absence of catenization indicate that Willwood floodplains were broad and essentially featureless. All Willwood paleosols were developed on alluvial parent materials and are complex in that B horizons of younger paleosols were commonly superimposed upon and mask properties of suspected A and B horizons of the next older paleosols. The soils appear to be wet varieties of the Spodosol and Entisol groups (aquods and ferrods, and aquents, respectively), though thick, superposed and less mottled red, purple, and yellow paleosols resemble some ultisols. Most Willwood paleosols resemble warm temperate to subtropical alluvial soils that form today under alternating wet and dry conditions and (or) fluctuating water tables. The up-section decrease in frequency of gley mottles, increase in numerical proportion and thickness of red versus orange coloration, and increase in abundance of calcrete glaebules indicate better drained soils and probably drier climate in late Willwood time. This drying is believed to be related to creation of rain shadows and spacing of rainfall (but not necessarily decrease in absolute rainfall) due to progressive tectonic structural elevation of the mountainous margins of the Bighorn Basin. ?? 1981.

Bown, T. M.; Kraus, M. J.

1981-01-01

411

An RTP Payload Format for MIDI  

Microsoft Academic Search

The Real-Time Protocol (RTP) is an extensible transport for sending media streams over Internet Protocol packet networks. We describe a new payload format that extends RTP to transport MIDI (the Musical Instrument Digital Interface command language). The payload format encodes all commands that may legally appear on a MIDI 1.0 DIN cable. The format is suitable for interactive applications (such

John Lazzaro; John Wawrzynek

2004-01-01

412

Magnetic Model Trap Formation of Volyn  

Microsoft Academic Search

In the article technique of magnetic modelling trap formation of Volyn (north-west Ukraine) is considered. It is investigated magnetic properties of rock trap formation, anomalous magnetic field and connection of these parameters with a technique of maning model. The model of a magnetic field was made. The comparative analysis with others trap formations of the world was carried out. Introduction

M. V. Yusypiv

2004-01-01

413

Sox9 is required for cartilage formation  

Microsoft Academic Search

Chondrogenesis results in the formation of cartilages, initial skeletal elements that can serve as templates for endochondral bone formation. Cartilage formation begins with the condensation of mesenchyme cells followed by their differentiation into chondrocytes. Although much is known about the terminal differentiation products that are expressed by chondrocytes, little is known about the factors that specify the chondrocyte lineage. SOX9

Weimin Bi; Jian Min Deng; Zhaoping Zhang; Richard R. Behringer; Benoit de Crombrugghe

1999-01-01

414

Star formation - From OB associations to protostars  

Microsoft Academic Search

A scenario for early stellar formation is presented, based on the current understanding of global processes (such as spiral density waves, sequential star formation, the dynamic evolution of OB associations and clusters and the initial mass function) and the formation and early evolution of individual objects. Studies of the early dynamical evolution of OB associations support the contention that the

Charles J. Lada

1987-01-01

415

Transfer of Training with Formation Flight Trainer.  

ERIC Educational Resources Information Center

The present research was conducted to determine transfer of practice from a formation simulator to actual aircraft flight for the wing aircraft component of the formation flying task. Evidence in support of positive transfer was obtained by comparing students trained in the formation simulator with students who were essentially untrained and with…

Reid, Gary B.; Cyrus, Michael L.

416

Formation Control Laws for Autonomous Flight Vehicles  

Microsoft Academic Search

The problem of aircraft formation dynamics and control is investigated from the viewpoint of formation architecture. Three different formation structures, leader-wingman, virtual leader and behavioral approaches are introduced. A comparative study is made using an unified approach through a suitable control law based on the dynamic inversion approach

Martina Chiaramonti; Fabrizio Giulietti; G. Mengali

2006-01-01

417

Approaches to vision-based formation control  

Microsoft Academic Search

This paper implements several methods for performing vision-based formation flight control of multiple aircraft in the presence of obstacles. No information is communicated between aircraft, and only passive 2-D vision information is available to maintain formation. The methods for formation control rely either on estimating the range from 2-D vision information by using extended Kalman Filters or directly regulating the

Eric N. Johnson; Anthony J. Calise; Ramachandra Sattigeri; Yoko Watanabe; Venkatesh Madyastha

2004-01-01

418

Research on missile formation control system  

Microsoft Academic Search

The control system of missile formation flight is described. In this paper, the missile formation flight controller and BTT intelligence missile outer-loop controller are interested. A combination of proportion and differential control of the position error is used in the designing of the missile formation flight controller to generate the control command for the single missile. The missile outer-loop controller

Naigang Cui; Changzhu Wei; Jifeng Guo; Biao Zhao

2009-01-01

419

Dynamic and control issues of formation flight  

Microsoft Academic Search

Two aspects of formation flight are addressed in this paper: dynamic modeling and formation control. In formation flight aircraft dynamics are coupled by aerodynamic effects due to the vortices leaving the lifting surfaces, such as changes in lift and drag forces and lateral\\/directional effects that do not appear in a steady-level ‘isolated’ flight. These aerodynamic effects are properly modeled with

Fabrizio Giulietti; Mario Innocenti; Marcello Napolitano; Lorenzo Pollini

2005-01-01

420

Decentralized formation control of autonomous mobile robots  

Microsoft Academic Search

Control of vehicle formations is an area of great interest that requires knowhow from several scientific areas such as control theory, vision, communication system, etc. In this work, several approaches to maintain a formation of vehicles are explained and tested. In this paper, the approach towards formation control is achieved through position based visual servoing (PBVS). In PBVS, a cartesian

Edwin Carvalho; Miguel Pedro Silva; Carlos Cardeira

2009-01-01

421

On new UAV formation flight control system  

Microsoft Academic Search

Combining Kalman filter with PID controller is applied to design UAV (Unmanned Air Vehicles) formation flight control system. It contains Kalman&PID controllers of speed and pitch angle for UAV. According to characteristic of UAV formation flight?» the PID parameters were adjusted to realize control stability of UAV in formation flight. The simulation results verify the validity and feasibility of the

Peng Zhang; Zhendong Liu

2011-01-01

422

Borehole flexural modes in anisotropic formations  

Microsoft Academic Search

A perturbation method of solution is an efficient way of analyzing elastic wave propagation along a borehole in anisotropic formations. The perturbation model allows one to calculate changes in the modal dispersion curves caused by the differences in elastic constants between the anisotropic formation of interest and a reference, or unperturbed, isotropic formation. The equivalent isotropic constants in the reference

Bikash K. Sinha; S. K. Chang; A. N. Norris

1994-01-01

423

Method of fracture acidizing a well formation  

Microsoft Academic Search

A method of fracture acidizing underground well formations is described. High-capacity flow channels are created and sustained in the formation, particularly in the area adjacent to the well bore, without the use of propping materials. The steps of the method are (1) inducing fractures in the formation, (2) contacting the faces of the fractures with acid while maintaining the fractures

J. A. Knox; S. E. Fredrickson

1973-01-01

424

Method of fracture acidizing a well formation  

Microsoft Academic Search

A method is described for fracture acidizing underground well formations so that the production of oil and gas is increased. High capacity flow channels are created and sustained in the formation, particularly in the area adjacent to the well bore. The method is based on the discovery that high capacity flow channels are formed in formation, if an induced fracture

J. A. Knox; S. E. Fredrickson

1974-01-01

425

A fast formation process for lithium batteries  

Microsoft Academic Search

The formation process presently used in the manufacture of lithium-ion batteries includes the solid electrolyte interface (SEI) growth process and another process for lithium intercalation into carbon. The latter process is both time and energy consuming. This study proposes a new concepts that can shorten the formation time by narrowing the potential range and bypassing the intercalation step during formation.

Hsiang-Hwan Lee; Yung-Yun Wang; Chi-Chao Wan; Mo-Hua Yang; Hung-Chun Wu; Deng-Tswen Shieh

2004-01-01

426

A new PICL trace file format  

SciTech Connect

A trace file format is described that will be used in future releases of the Portable Instrumented Communication Library (PICL) and ParaGraph. The new format provides improved support for tracing and profiling PICL communication primitives and user-defined events. The new format is also easily extended and may be useful in other instrumentation packages and performance visualization tools.

Worley, P.H.

1992-10-01

427

Tight oil or gas formation fracturing process  

Microsoft Academic Search

A process for fracturing tight oil or gas formations is described. A band of small holes is drilled into the oil or gas formation from a well borehole, so that more explosive or hydraulic fracturing fluids can be placed at a selected depth and positioned to provide more lifting and fracturing force on the oil or gas formation. The holes

Driver

1974-01-01

428

Formative Assessment: Responding to Your Students  

ERIC Educational Resources Information Center

This "how-to" book on formative assessment is filled with practical suggestions for teachers who want to use formative assessment in their classrooms. With practical strategies, tools, and examples for teachers of all subjects and grade levels, this book shows you how to use formative assessment to promote successful student learning. Topics…

Tuttle, Harry Grover

2009-01-01

429

Surfactant effects on gas hydrate formation  

Microsoft Academic Search

Micellar solutions were found to increase gas hydrate formation rate and alter formation mechanism for ethane and natural gas hydrates. A critical micellar concentration (CMC) of sodium dodecyl sulfate water solution was found to be 242 ppm at hydrate-forming conditions, where CMC was best determined by hydrate induction time. At surfactant concentrations above the CMC, hydrate formation rates in a

Y. Zhong; R. E. Rogers

2000-01-01

430

Formation of Magnesium Silicide by Mechanical Alloying  

Microsoft Academic Search

Elemental Mg and Si powders were mechanically alloyed in a planetary ball mill. The formation of magnesium silicide as well as the formation of magnesium oxide and hydride in the milled powders was studied in detail by X-ray diffraction and scanning differential calorimetry. It was found that direct formation of the magnesium silicide, Mg2Si, occurred after 10 hours of milling

Xiaoping Niu; Li Lu

1997-01-01

431

GXL: Toward a Standard Exchange Format  

Microsoft Academic Search

This paper describes ongoing work toward the devel- opment of a standard software exchange format (SEF), for exchanging information among tools that analyze com- puter programs. A particular exchange format called GXL (Graph Exchange Language) is proposed. GXL can be viewed as a merger of well known formats (e. g. GraX, PRO- GRES, RPA, RSF, and TA) for exchanging typed,

Richard C. Holt; Andreas Winter; Andy Schiirr

2000-01-01

432

Tube Formation in Nanoscale Materials  

PubMed Central

The formation of tubular nanostructures normally requires layered, anisotropic, or pseudo-layered crystal structures, while inorganic compounds typically do not possess such structures, inorganic nanotubes thus have been a hot topic in the past decade. In this article, we review recent research activities on nanotubes fabrication and focus on three novel synthetic strategies for generating nanotubes from inorganic materials that do not have a layered structure. Specifically, thermal oxidation method based on gas–solid reaction to porous CuO nanotubes has been successfully established, semiconductor ZnS and Nb2O5nanotubes have been prepared by employing sacrificial template strategy based on liquid–solid reaction, and an in situ template method has been developed for the preparation of ZnO taper tubes through a chemical etching reaction. We have described the nanotube formation processes and illustrated the detailed key factors during their growth. The proposed mechanisms are presented for nanotube fabrication and the important pioneering studies are discussed on the rational design and fabrication of functional materials with tubular structures. It is the intention of this contribution to provide a brief account of these research activities.

2008-01-01

433

Beaver assisted river valley formation  

USGS Publications Warehouse

We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in-channel beaver dams. Our data show a 1.7-m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient-rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de-watered following the dam breach by high stream flows, protecting the deposited sediment from future re-mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re-occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. ?? 2010 John Wiley & Sons, Ltd.

Westbrook, C. J.; Cooper, D. J.; Baker, B. W.

2011-01-01

434

Montezuma Formation of Costa Rica  

SciTech Connect

The Montezuma Formation of the Nicoya Peninsula is one of the better known Neogene stratigraphic units of the Pacific side of Costa Rica. Past workers have reported its age to be Miocene-Pliocene or Miocene-Quaternary, and its environment of deposition to be inner shelf. The planktonic foraminiferal record of the unit in the type locality, however, places it firmly in the Lower Pliocene (Globorotalia margaritae zones). Furthermore, benthic such as Bolivina interjuncta var. bicostata, Epistominella exigua, and E. pacifica indicate that the sedimentation occurred at depths no shallower than the outermost shelf. No drastic faunal turnovers are observed within the formation; a cluster analysis of various Neogene samples from the Nicoya Peninsula and other Pacific areas of Costa Rica demonstrate an overall uniformity of the Montezuma fauna. The frequency trends of certain species, particularly of Epistominella exigua, however, suggest a transgression, the assemblage in the upper part of the section definitely representing upper bathyal depths. Judging by the present elevation of Montezuma outcrops, this part of Costa Rica has been uplifted at least 300 meters in the past 5 m.y.

McKee, W.H.; Sen Gupta, B.K.

1985-01-01

435

Dynamical ? models of structure formation  

NASA Astrophysics Data System (ADS)

Models of structure formation with a cosmological constant ? provide a good fit to the observed power spectrum of galaxy clustering. However, they suffer from several problems. Theoretically, it is difficult to understand why the cosmological constant is so small in Planck units. Observationally, while the power spectra of cold dark matter plus ? models have approximately the right shape, the COBE-normalized amplitude for a scale-invariant spectrum is too high, requiring galaxies to be antibiased relative to the mass distribution. Attempts to address the first problem have led to models in which a dynamical field supplies the vacuum energy, which is thereby determined by fundamental physics scales. We explore the implications of such dynamical ? models for the formation of large-scale structure. We find that there are dynamical models for which the amplitude of the COBE-normalized spectrum matches the observations. We also calculate the cosmic microwave background anisotropies in these models and show that the angular power spectra are distinguishable from those of standard cosmological constant models.

Coble, Kimberly; Dodelson, Scott; Frieman, Joshua A.

1997-02-01

436

Recent concepts in plaque formation.  

PubMed

Dental plaque is an adherent, bacterial film, and is the main pathological agent for periodontal diseases. The formation of dental plaque can occur both supragingivally and subgingivally. The development of plaque is a three-step process. Following the formation of a pellicle, pioneer micro-organisms will adhere to it, proliferate and form colonies. The final stage involves the aggregation of filamentous organisms and spirochetes into a cohesive biofilm. Many products of the plaque bacteria reach the subepithelial tissue, causing inflammatory responses such as increased vascularity and leukocyte diapedesis. Both supragingival and subgingival plaque may form a hard, mineralized mass called calculus. The surface of calculus harbours bacteria, which may exacerbate the inflammatory responses. An effective oral antiseptic must be active against a wide range of Gram-positive and Gram-negative bacterial species, including streptococci and fusobacteria. Ideally, an effective agent would also penetrate the plaque biofilm. Data show that essential oil and chlorhexidine mouthwashes have the broadest antimicrobial effects. PMID:12787195

Bernimoulin, J-P

2003-01-01

437

Coring in deep hardrock formations  

SciTech Connect

The United States Department of Energy is involved in a variety of scientific and engineering feasibility studies requiring extensive drilling in hard crystalline rock. In many cases well depths extend from 6000 to 20,000 feet in high-temperature, granitic formations. Examples of such projects are the Hot Dry Rock well system at Fenton Hill, New Mexico and the planned exploratory magma well near Mammoth Lakes, California. In addition to these programs, there is also continuing interest in supporting programs to reduce drilling costs associated with the production of geothermal energy from underground sources such as the Geysers area near San Francisco, California. The overall progression in these efforts is to drill deeper holes in higher temperature, harder formations. In conjunction with this trend is a desire to improve the capability to recover geological information. Spot coring and continuous coring are important elements in this effort. It is the purpose of this report to examine the current methods used to obtain core from deep wells and to suggest projects which will improve existing capabilities. 28 refs., 8 figs., 2 tabs.

Drumheller, D.S.

1988-08-01

438

Cooper Pair Formation in Acenes  

NASA Astrophysics Data System (ADS)

We have measured the ratio of doubly to singly charged molecular parent ions of benzene, naphthalene, anthracene, and pyrrole over a wide range of photon energies. About 40 eV above the double-ionization threshold, the first three of the above molecules exhibit a hump of very similar shape and magnitude in the double-to-single photoionization ratio, which we attribute to the formation and emission of an electron Cooper pair from a free molecule. Our results suggest that the de Broglie wave of this highly correlated pair of electrons forms a closed loop in the system of overlapping ? bonds with a wavelength that matches the distance between neighboring carbon atoms. Pyrrole with its pentagonal structure does not allow the formation of a closed de Broglie wave and, thus, does not exhibit a hump in the ratio. Photoelectron measurements indicate the break-up of the emitted Cooper pair by two electron peaks sitting on top of the mainly U-shaped double-ionization continuum in support of our interpretation.

Hartman, Tim; Jurani?, Pavle; Collins, Kelly; Reilly, Bethany; Appathurai, Narayana; Whitfield, Scott B.; Wehlitz, Ralf

2012-06-01

439

Multiresolution FOPEN SAR image formation  

NASA Astrophysics Data System (ADS)

This paper presents a new technique for FOPEN SAR (foliage penetration synthetic aperture radar) image formation of Ultra Wideband UHF radar data. Planar Subarray Processing (PSAP) has successfully demonstrated the capability of forming multi- resolution images for X and Ka band radar systems under MITRE IR&D and the DARPA IBC program. We have extended the PSAP algorithm to provide the capability to form strip map, multi- resolution images for Ultra Wideband UHF radar systems. The PSAP processing can accommodate very large SAR integration angles and the resulting very large range migration. It can also accommodate long coherent integration times and wide swath coverage. Major PSAP algorithm features include: multiple SAR sub-arrays providing different look angles at the same image area that can enable man-made target responses to be distinguished from other targets and clutter by their angle dependent specular characteristics, the capability to provide a full resolution image in these and other selected areas without the processing penalty of full resolution in non required areas, and the capability to include angle-dependent motion compensation within the image formation process.

Dipietro, Robert C.; Fante, Ronald L.; Perry, Richard P.; Soumekh, Mehrdad; Tromp, Laurens D.

1999-08-01

440

Dilatational band formation in bone  

PubMed Central

Toughening in hierarchically structured materials like bone arises from the arrangement of constituent material elements and their interactions. Unlike microcracking, which entails micrometer-level separation, there is no known evidence of fracture at the level of bone’s nanostructure. Here, we show that the initiation of fracture occurs in bone at the nanometer scale by dilatational bands. Through fatigue and indentation tests and laser confocal, scanning electron, and atomic force microscopies on human and bovine bone specimens, we established that dilatational bands of the order of 100 nm form as ellipsoidal voids in between fused mineral aggregates and two adjacent proteins, osteocalcin (OC) and osteopontin (OPN). Laser microdissection and ELISA of bone microdamage support our claim that OC and OPN colocalize with dilatational bands. Fracture tests on bones from OC and/or OPN knockout mice (OC?/?, OPN?/?, OC-OPN?/?;?/?) confirm that these two proteins regulate dilatational band formation and bone matrix toughness. On the basis of these observations, we propose molecular deformation and fracture mechanics models, illustrating the role of OC and OPN in dilatational band formation, and predict that the nanometer scale of tissue organization, associated with dilatational bands, affects fracture at higher scales and determines fracture toughness of bone.

Poundarik, Atharva A.; Diab, Tamim; Sroga, Grazyna E.; Ural, Ani; Boskey, Adele L.; Gundberg, Caren M.; Vashishth, Deepak

2012-01-01

441

Virialization Heating in Galaxy Formation  

SciTech Connect

In a hierarchical picture of galaxy formation virialization continually transforms gravitational potential energy into kinetic energies in the baryonic and dark matter. For the gaseous component the kinetic, turbulent energy is transformed eventually into internal thermal energy through shocks and viscous dissipation. Traditionally this virialization and shock heating has been assumed to occur instantaneously allowing an estimate of the gas temperature to be derived from the virial temperature defined from the embedding dark matter halo velocity dispersion. As the mass grows the virial temperature of a halo grows. Mass accretion hence can be translated into a heating term. We derive this heating rate from the extended Press Schechter formalism and demonstrate its usefulness in semi-analytical models of galaxy formation. Our method is preferable to the traditional approaches in which heating from mass accretion is only modeled implicitly through an instantaneous change in virial temperature. Our formalism can trivially be applied in all current semi-analytical models as the heating term can be computed directly from the underlying merger trees. Our analytic results for the first cooling halos and the transition from cold to hot accretion are in agreement with numerical simulations.

Wang, P. (KIPAC, Menlo Park); Abel, T. (Santa Barbara, KITP)

2007-01-17

442

A formulation of stability for spacecraft formations  

NASA Technical Reports Server (NTRS)

A formulation of stability for a set of spacecraft in formation flight is presented. First, a formation is defined in a precise mathematical form in terms of control interactions. Then, stability is formulated based on input-to-output stability with respect to a partitioning of the formation dynamics. This formulation of stability is shown to be useful in characterizing disturbance propagation in the formation as a function of the partition interconnection topology, and also in analyzing the robustness of sensing, communication, and control topologies. Stability results are presented for hierarchical, cyclic, and disturbance attenuating formations.

Acikmese, Ahmet Behcet; Hadaegh, Fred Y.; Scharf, Daniel P.; Ploen, Scott R.

2005-01-01

443

Thin Structure Formation in an Accretion Disk's Magnetosphere  

NASA Astrophysics Data System (ADS)

We examine the behavior of the magnetic field lines in a magnetically linked star--disk system. The rotation of the accretion disk with respect to the central star causes the field lines to twist up and inflate dramatically on the rotation period time scale. Our main goal is to see under which conditions the expanding field lines could form a thin current sheet in the magnetosphere above the disk, as the twist angle is increased. In order to investigate this question, we develop a simple analytical model based on the force-free Grad-Shafranov equation. This model enables us to estimate the angular width of the current concentration region in terms of the twist angle of the field lines. We observe that thin structures in the magnetosphere may form in the case of a nonuniformly rotating disk, in particular, for field lines attached to the disk in the region where the twist angle varies rapidly with radius (e.g., at the inner edge of the disk). We discuss the relevance of our findings to the possibility of magnetic reconnection above the disk, as well as some other astrophysical implications. Work supported by ASCII/Alliances Center for Astrophysical Thermonuclear Flashes under DOE subcontract B341495.

Uzdensky, D. A.

2001-05-01

444

The HI/Star Formation Connection  

NASA Astrophysics Data System (ADS)

There have been many observational programs exploring the connection between the HI distribution and the presence of star formation in galaxies. Since the molecular phase of the ISM is most closely associated with star formation, the results of these investigations depend greatly on the type of galaxy being observed. For low mass, low metallicity galaxies, where the molecular gas in only found associated with the densest concentrations of HI, the correlation between HI maxima and star formation is very good. For high mass, high metallicity galaxies, star formation correlates strongly with densest concentrations of molecular gas, and the majority of the HI gas can be unrelated to star formation. Understanding the HI/star formation connection requires observations of the quality being produced by the THINGS program. The THINGS sample is especially promising due to the abundance and quality of the ancillary observational databases. As a forward look, I pose the question: How many galaxies do we need to observe with this quality of data in order to answer our fundamental questions concerning the star formation process? An important part of the answer is that we need to carefully study those galaxies and regions of galaxies which do not show current star formation in order to understand the absence of star formation as well as the presence of star formation. I describe a method of recreating star formation histories of galaxies over the last ~500 Myr which will help us to understand how the gas has come to its present state.

Skillman, Evan D.

2008-08-01

445

Formation Flying for Distributed InSAR  

NASA Technical Reports Server (NTRS)

We consider two spacecraft flying in formation to create interferometric synthetic aperture radar (InSAR). Several candidate orbits for such in InSar formation have been previously determined based on radar performance and Keplerian orbital dynamics. However, with out active control, disturbance-induced drift can degrade radar performance and (in the worst case) cause a collision. This study evaluates the feasibility of operating the InSAR spacecraft as a formation, that is, with inner-spacecraft sensing and control. We describe the candidate InSAR orbits, design formation guidance and control architectures and algorithms, and report the (Delta)(nu) and control acceleration requirements for the candidate orbits for several tracking performance levels. As part of determining formation requirements, a formation guidance algorithm called Command Virtual Structure is introduced that can reduce the (Delta)(nu) requirements compared to standard Leader/Follower formation approaches.

Scharf, Daniel P.; Murray, Emmanuell A.; Ploen, Scott R.; Gromov, Konstantin G.; Chen, Curtis W.

2006-01-01

446

Mean depths of line formation  

NASA Astrophysics Data System (ADS)

A straightforward reasonable physical definition of a mean depth is effected by means of the expectation value used in mathematical statistics. The real atmosphere is replaced by a fixed layer situated at the mean depth of line formation from which the observed intensity or flux emerges. Applied to the emergent line depression it is not possible to define a fixed depth but a thickness of an absorbing layer forming the absorption line. These two values have a different physical meaning and must not be confused with one another. The mean depth is calculated approximately by taking the arithmetic mean of the depths weighted with the absorption along the path outwards. This immediately leads to the well known Eddington/Barbier method.

Gussmann, E. A.

447

Supercoil formation in DNA denaturation.  

PubMed

We generalize the Poland-Scheraga model to the case of a circular DNA, taking into account the twisting of the two strains around each other. Guided by recent single-molecule experiments on DNA strands, we assume that the torsional stress induced by denaturation enforces the formation of supercoils whose writhe absorbs the linking number expelled by the loops. Our model predicts that when the entropy parameter of a loop satisfies c2, a first-order denaturation transition is consistent with our model and may take place in the actual system, as in the case with no supercoils. These results are in contrast with other treatments of circular DNA melting where denaturation is assumed to be accompanied by an increase in twist rather than writhe on the bound segments. PMID:19658646

Kabakçio?lu, A; Orlandini, E; Mukamel, D

2009-07-01

448

Lunar and terrestrial crust formation  

NASA Astrophysics Data System (ADS)

Planetary crusts may be accreted, produced in primordial differentiation, or built up piecemeal by serial magmatism. The existence of old, polygenetic, laterally heterogeneous, partial melt rocks in the lunar highlands suggests that the moon produced its early crust by serial magmatism. This view can be reconciled with lunar Eu anomalies, previously thought to support the magma ocean model of crust formation, if complications in the fractionation of mare basalts are recognized. Phase equilibrium and magmatic density information for mare basalts suggest a model in which plagioclase fractionation can occur even though plagioclase is not a near-liquidus phase. The cryptic fractionation of clinopyroxene in MORB provides a precedent for this model. The necessity for a lunar magma ocean is questioned, but a role for a terrestrial magma ocean of sorts at depths is suggested.

Walker, D.

1983-11-01

449

Foam formation in low gravity  

NASA Technical Reports Server (NTRS)

An apparatus that produced the first polyurethane foam in low gravity has been described. The chemicals were mixed together in an apparatus designed for operation in low gravity. Mixing was by means of stirring the chemicals with an electric motor and propeller in a mixing chamber. The apparatus was flown on Consort 1, the first low-gravity materials payload launched by a commercial rocket launch team. The sounding rocket flight produced over 7 min of low gravity during which a polyurethane spheroidal foam of approximately 2300 cu cm was formed. Photographs of the formation of the foam during the flight show the development of the spheroidal form. This begins as a small sphere and grows to approximately a 17-cm-diam spheroid. The apparatus will be flown again on subsequent low-gravity flights.

Wessling, Francis C.; Mcmanus, Samuel P.; Matthews, John; Patel, Darayas

1990-01-01

450

Polar cap formation on Ganymede  

NASA Technical Reports Server (NTRS)

Since thermal migration is not an effective mechanism for water transport in the polar regions at the Galilean satellites, some other process must be responsible for the formation of Ganymede's polar caps. It is proposed that Ganymede's polar caps are the optical manifestation of a process that began with the distribution of an ice sheet over the surface of Ganymede. The combined processes of impact gardening and thermal migration led, in regions at latitudes less than 40 to 45 deg., to the burial of some fraction of this ice, the migration of some to the polar caps margins, and a depletion of free ice in the optical surface. At higher latitudes, no process was effective in removing ice from the optical surface, so the remanants of the sheet are visible today.

Pilcher, C. B.; Shaya, E. J.

1985-01-01

451

Structural aspects of amyloid formation.  

PubMed

Amyloid fibrils are highly organized and generally insoluble protein aggregates rich in ? secondary structure that can be formed by a wide range of sequences. They have been the object of intense scrutiny because their formation has been associated with a number of neurodegenerative disorders such as Alzheimer's, Parkinson's, Huntington's, and Creutzfeldt-Jakob's diseases. As a consequence of these efforts, much is now known about the properties of proteins that render them prone to form amyloid fibrils, about the mechanism of fibrillation, about the molecular structures of the fibrils, and about the forces that stabilize them. The relationship between the structural properties of the monomeric protein and those of the corresponding aggregate has been, in particular, intensively studied. In this chapter, we will provide an account of current knowledge on this intriguing relationship and provide the reader with key references about this topic. PMID:23663966

Salvatella, Xavier

2013-01-01

452

Statoconia formation in molluscan statocysts  

NASA Technical Reports Server (NTRS)

The gravity sensors of all molluscs phylogenetically below the cephalopods are spherical organs called statocysts. The wall of the sphere contains mechanosensory cells whose sensory cilia project into the lumen of the cyst. The lumen is filled with fluid and dense "stones", the statoconia or statoliths, which sink under the influence of gravity to load, and stimulate, those receptor cells which are at the bottom. The statoconia of Aplysia californica are shown to be calcified about a lamellar arrangement of membranes. Similar lamellar membrane arrangements are seen within the receptor cells, and their possible role in the formation of the statoconia is discussed. SEM of unfixed statoconia reveals plate-like crystallization on their surface. Elemental analysis shows a relatively high Sr content, which is of interest, since others have recently reported that Sr is required in the culture medium of several laboratory reared molluscs in order for the statoconia to develop.

Wiederhold, M. L.; Sheridan, C. E.; Smith, N. K.

1986-01-01

453

Solids formation on filtrate neutralization  

SciTech Connect

The Separations Technology Laboratory was requested to study what happens when a filtrate solution, which will be a F B-Line product, is neutralized with sodium hydroxide. The primary concern was the formation of solids that could cause damage in pump seals, resulting in their failure. The results of these experiments indicate that under process conditions, granular, crystalline sodium fluoride will be produced by rapid neutralization of the filtrate solution with 50% NaOH plus a 25 volume percent excess. Postprecipitation of sodium oxalate-sodium fluoride and its accumulation can occur over a three-week storage period of the neutralized filtrate. Such solids could pose operational problems from pump seal abrasion and potential failure caused by them.

Holcomb, H.P.

1988-05-26

454

Meander formation in supraglacial streams  

NASA Astrophysics Data System (ADS)

Meandering streams on the surface of glaciers are similar in planform geometry to meanders in alluvial and bedrock rivers, despite fundamental differences in the mechanisms and timescales of incision. We develop depth-averaged conservation equations for flow in such supraglacial channels with erodible boundaries and solve the linear stability problem for harmonic perturbations to an initially straight channel. Meander formation in supraglacial streams is driven by channel curvature, which enhances heat production and heat transfer to the surrounding ice at bend apexes. This leads to enhanced melting and lateral channel migration, with near constant channel width maintained by the competition of lateral erosion and broadscale ablation of the glacier surface. We find that meandering occurs for a wide but finite range of hydraulic and thermal parameters in both subcritical and supercritical flows and that meanders usually propagate downstream. Predicted meander wavelengths are in general agreement with an empirical scaling between supraglacial channel width and meander wavelength derived from glacial environments worldwide.

Karlstrom, Leif; Gajjar, Parmesh; Manga, Michael

2013-09-01

455

Nanofiber formation of hydroxylpropylcellulose (HPC).  

PubMed

The aggregative behaviors of hydroxypropylcellulose (HPC) molecules in aqueous solution and on substrates have been observed by employing laser light scattering (LLS) and, after deposition on a mica surface, atomic force microscopy (AFM). LLS studies showed that the HPC molecules formed large aggregates through self-association when the concentration of the solution was above the critical concentration c(t). AFM measurements revealed that when a dilute aqueous solution of HPC molecules was deposited onto a mica substrate at a temperature below its lower critical solution temperature (LCST) thin nanofibers were formed with a height of 0.9 nm, whereas thick nanofibers were formed when an aqueous solution of HPC molecules was deposited onto a substrate above its LCST. Furthermore, the growth of nanofibers led to the formation of fan structures. PMID:16921540

Yan, Lifeng; Lin, Wei; Bangal, Prakriti R

2006-07-14

456

Opinion formation in laggard societies  

NASA Astrophysics Data System (ADS)

We introduce a statistical-physics model for opinion dynamics on random networks where agents adopt the opinion held by the majority of their direct neighbors only if the fraction of these neighbors exceeds a certain threshold, pu. We find a transition from total final consensus to a mixed phase where opinions coexist amongst the agents. The relevant parameters are the relative sizes in the initial opinion distribution within the population and the connectivity of the underlying network. As the order parameter we define the asymptotic state of opinions. In the phase diagram we find regions of total consensus and a mixed phase. As the "laggard parameter" pu increases the regions of consensus shrink. In addition we introduce rewiring of the underlying network during the opinion formation process and discuss the resulting consequences in the phase diagram.

Klimek, P.; Lambiotte, R.; Thurner, S.

2008-04-01

457

Electrochemical formation of field emitters  

DOEpatents

Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays is disclosed. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area. 12 figs.

Bernhardt, A.F.

1999-03-16

458

The Science of Galaxy Formation  

NASA Astrophysics Data System (ADS)

Our knowledge of the Universe remains discovery-led: in the absence of adequate physics-based theory, interpretation of new results requires a scientific methodology. Commonly, scientific progress in astrophysics is motivated by the empirical success of the “Copernican Principle”, that the simplest and most objective analysis of observation leads to progress. A complementary approach tests the prediction of models against observation. In practise, astrophysics has few real theories, and has little control over what we can observe. Compromise is unavoidable. Advances in understanding complex non-linear situations, such as galaxy formation, require that models attempt to isolate key physical properties, rather than trying to reproduce complexity. A specific example is discussed, where substantial progress in fundamental physics could be made with an ambitious approach to modelling: simulating the spectrum of perturbations on small scales.

Gilmore, Gerard

2009-03-01

459

Selective formation of tungsten nanowires  

PubMed Central

We report on a process for fabricating self-aligned tungsten (W) nanowires with polycrystalline silicon core. Tungsten nanowires as thin as 10 nm were formed by utilizing polysilicon sidewall transfer technology followed by selective deposition of tungsten by chemical vapor deposition (CVD) using WF6 as the precursor. With selective CVD, the process is self-limiting whereby the tungsten formation is confined to the polysilicon regions; hence, the nanowires are formed without the need for lithography or for additional processing. The fabricated tungsten nanowires were observed to be perfectly aligned, showing 100% selectivity to polysilicon and can be made to be electrically isolated from one another. The electrical conductivity of the nanowires was characterized to determine the effect of its physical dimensions. The conductivity for the tungsten nanowires were found to be 40% higher when compared to doped polysilicon nanowires of similar dimensions.

2011-01-01

460

Pseudoaneurysm formation in infective endocarditis.  

PubMed

Left ventricular pseudoaneurysms that develop in the setting of infective endocarditis are believed to result from remodeling of extravalvular abscesses. The high pressure generated by the left ventricle is thought to dissect into the abscess causing it to form a characteristic sac-like protuberance readily recognized echocardiographically. Left ventricular pseudoaneurysms most often arise from abscesses in the mitral-aortic intervalvular fibrosa and protrude external to the aorta. Less often, as described herein, they arise from abscesses external the posterior mitral annulus and project into the posterior interventricular groove. Perforation may result in camo-cameral or aorto-cameral fistula formation, as well as fistulous communication with the pericardial space. PMID:23906264

Silbiger, Jeffrey J; Krasner, Andrew; Chikwe, Joanna; Marino, Thomas; Mathewkutty, Shiny; Marcali, Marian; Edebohls, Brian; Kamran, Mazullah

2013-11-01