Observations of a Unique Type of ULF Waves by Low-Latitude Space Technology Five Mission
We report a unique type of ULF waves observed by low-altitude Space Technology 5 (ST-5)
2011-01-01
the earth observer - Earth Observing System - NASA
of satellite, aircraft and ground-based observations. In ..... swarm traps by Utah Department of Food and Agriculture (DAF) personnel. Preliminary Results ..... the 150th anniversary of the book's publication and the 200th anniversary of Darwin's birth. ...... cold war submarine missions to find that Arctic Ocean ...
The search for decaying Dark Matter
We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry ...
2009-01-01
Development of a Long-Range Gliding Underwater Vehicle ...
... investigates the convergence of three main areas of UUV development; mission ... with an improved low-cost embedded-system robot controller, to ...
2008-09-01
European Space Power Conference
International Nuclear Information System (INIS)
To support the Space Exploration Initiative (SEI), a study was performed to investigate power system alternatives for the rover vehicles and servicers that were subsequently generated for each of these rovers and servicers, candidate power sources incorporating various power generation and energy storage technologies were identified. The technologies were those believed most appropriate to the SEI missions, and included solar, electrochemical, and isotope systems. The candidates were characterized with respect to system mass, deployed area, and volume. For each of the missions a preliminary selection was made. Results of this study depict the available power sources in light of mission requirements as they are currently defined.
1991-09-02
Fiscal year 1996 U.S. Department of Energy, Richland Operations Office Site summary baseline
International Nuclear Information System (INIS)
The technical baseline is a hierarchical description of the Hanford Site cleanup mission. This technical baseline does not address the science, technology, or economic transition missions. It begins with a definition of the existing conditions at the Hanford Site, provides a description of the end product or mission accomplishments at completion, presents a statement of the major requirements and constraints that must be observed during the performance of the mission, and provides a statement of the top-level strategic approach to accomplish the mission. Mission-level interfaces are also described. This information is further defined hierarchically in increasing levels of detail. This definition is composed of the following major elements: functions that are key task descriptions; requirements that are the measurable standards to which the ...
2009-06-01
Energy Technology Data Exchange (ETDEWEB)
The PAMELA (a Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics) space mission has been launched on-board the Resurs-DK1 satellite on June 15{sup th} 2006 from the Baikonur cosmodrome, in Kazakhstan. PAMELA is a particle spectrometer designed to study charged particles in the cosmic radiation with special focus on the investigation of the nature of dark matter, by mean of the measure of the cosmic-ray antiproton and positron spectra over the largest energy range ever achieved.
2009-03-15
Geosynchronous orbit magnetopause crossings
Energy Technology Data Exchange (ETDEWEB)
In this study we extend the analysis of magnetopause crossings observed with Magnetospheric Plasma Analyzer measurements to examine a much larger statistical data set. This study examines 39 maiznetosheath/LLBL intervals from 79 spacecraft-months of observations: these observations were taken from a survey of data from the start of each spacecraft mission and extending through March 1993. In contrast to the previous findings, we find no evidence for a significant dawn/dusk asymmetry in geosynchronous magnetopause crossings.
1994-07-01
The Effect of Lunar-like Satellites on the Orbital Infrared Light Curves of Earth-analog Planets
We investigate the influence of lunar-like satellites on the infrared orbital light curves of Earth-analog extra-solar planets. Such light curves will be obtained by NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions as a consequence of repeat observations to confirm the companion status of a putative planet. We use an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from planet-satellite systems over a full orbital period (one year). The satellites are assumed to lack an atmosphere, have a low thermal inertia like that of the Moon and span a range of plausible radii. The planets are assumed to have thermal and orbital properties that mimic those of the Earth while their obliquities and orbital longitudes of inferior conjunction remain free parameters. Even if the gross thermal properties of the planet can be independently constrained (e.g. via spectroscopy or visible-wavelength ...
2008-01-01
Oral histories at the Hanford Nuclear Reservation
Energy Technology Data Exchange (ETDEWEB)
The founding of the Hanford Engineering Works to produce plutonium is described. The 45-year defense mission has now been replaced with a peaceful mission, that of being the first site for massive cleanup of the 45-year nuclear waste. In order to establish a remedial investigation and feasibility plan, a process of discovery named the Technical Baseline Report must be performed; the task of this process is to discover all that is known about a proposed cleanup site (what the waste was, where did it go). When none of the documentation can answer the question, oral history is utilized. Some of the problems associated with the conduct of oral history interviews are described, particularly Hanford`s legacy of secrecy.
1992-03-01
Java Mission Evaluation Workstation System
The Java Mission Evaluation Workstation System (JMEWS) is a collection of applications designed to
2006-01-01
Kepler Mission Stellar and Instrument Noise Properties
Kepler Mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination ...
2011-01-01
RECENT ACTIVITIES AT THE CENTER FOR SPACE NUCLEAR RESEARCH FOR DEVELOPING NUCLEAR THERMAL ROCKETS
Energy Technology Data Exchange (ETDEWEB)
Nuclear power has been considered for space applications since the 1960s. Between 1955 and 1972 the US built and tested over twenty nuclear reactors/ rocket-engines in the Rover/NERVA programs. However, changes in environmental laws may make the redevelopment of the nuclear rocket more difficult. Recent advances in fuel fabrication and testing options indicate that a nuclear rocket with a fuel form significantly different from NERVA may be needed to ensure public support. The Center for Space Nuclear Research (CSNR) is pursuing development of tungsten based fuels for use in a NTR, for a surface power reactor, and to encapsulate radioisotope power sources. The CSNR Summer Fellows program has investigated the feasibility of several missions enabled by the NTR. The potential mission benefits of a nuclear rocket, historical achievements of the previous programs, and recent investigations into alternatives ...
2001-09-01
Mission Science Calibration and Validation Plan - SMAP
Nov 16, 2010 ... In situ observations are usually made point-wise and the problem in using ...... also discussion of adaptive filtering in Section 4.1.2 of the L4_SM ...... L2-SR -265 SMAP shall provide a Level 1C radar sigma-0 product ...
CORONAL OBSERVATIONS OF CMEs Report of Working Group A
imaging of the solar corona began in 1960 via a primitive pinhole camera on a ... IR wavelengths. Such data help us to study in detail the pre-eruptive ...... Schematic picture of flare loops, CME, and the current sheet between ..... As part of NASA's Living With a Star (LWS) program the planned Sentinel mission ...
Energy Technology Data Exchange (ETDEWEB)
In this paper the possibility of configuring a water cooled Nuclear Thermal Propulsion (NTP) rocket, based on a Particle Bed Reactor (PBR) is investigated. This rocket will be used to operate on water obtained from near earth objects. The conclusions reached in this paper indicate that it is possible to configure a PBR based NTP rocket to operate on water and meet the mission requirements envisioned for it. No insurmountable technology issues have been identified.
1993-06-01
Energy Technology Data Exchange (ETDEWEB)
The Buried Waste Integrated Demonstration (BWID) is a program of the Department of Energy (DOE) Office of Technology Development whose mission is to evaluate different new and existing technologies and determine how well they address DOE community waste remediation problems. Twenty-three Technical Task Plans (TTPs) have been identified to support this mission during FY-92; 10 of these have identified some support requirements when demonstrations take place. Section 1 of this report describes the tasks supported by BWID, determines if a technical demonstration is proposed, and if so, identifies the support requirements requested by the TTP Principal Investigators. Section 2 of this report is an evaluation identifying facility characteristics of existing Idaho National Engineering Laboratory (INEL) facilities that may be considered for use in BWID technology demonstration activities.
1992-04-01
National Aeronautics and Space Administration (NASA)
NASA's Glory spacecraft is equipped to survey and map aerosols in Earth's atmosphere during a mission marking the return to flight of the Taurus XL rocket.
2011-02-22
Energy Technology Data Exchange (ETDEWEB)
The present study treats only the collective risk of ex-utero leukaemia associated with the routine releases of the nuclear industrial installations of the North Cotentin (0.0009 cases over the considered period) the uncertainty on the contribution to the collective risk of the incidents and the accidents of the nuclear installations (notably the drilling of the pipe of release in sea arisen in 1979-1980 and the fire of the waste silo on January 6. 1981, for the reprocessing plant of La Hague has not been considered. Only 45% of the risk are taken into account by the study. Every calculated value remains very inferior to the number of leukemia cases observed (4 cases observed for two expected cases) and to the risk of radioinduced leukemia any merged exposure sources, that is to say 0.84 cases. It appears thus not very probable that the nuclear installations of the North - Cotentin can explain the tendency to the excess of ...
2003-03-15
European Space Agency announces contest to "Name the Cluster Quartet"
1. Contest rules The European Space Agency (ESA) is launching a public competition to find the most suitable names for its four Cluster II space weather satellites. The quartet, which are currently known as flight models 5, 6, 7 and 8, are scheduled for launch from Baikonur Space Centre in Kazakhstan in June and July 2000. Professor Roger Bonnet, ESA Director of Science Programme, announced the competition for the first time to the European Delegations on the occasion of the Science Programme Committee (SPC) meeting held in Paris on 21-22 February 2000. The competition is open to people of all the ESA member states (*). Each entry should include a set of FOUR names (places, people, or things from history, mythology, or fiction, but NOT living persons). Contestants should also describe in a few sentences why their chosen names would be appropriate for the four Cluster II satellites. The winners will be those which are considered most suitable and relevant for the Cluster II ...
2000-02-01
The GEOFLOW experiment missions in the Fluid Science Laboratory on ISS
The GEOFLOW I experiment has been successfully performed on the International Space Sta-tion (ISS) in 2008 in the Columbus module in order to study the stability, pattern formation and transition to turbulence in a viscous incompressible fluid layer enclosed in two concentric co-rotating spheres subject to a radial temperature gradient and a radial volumetric force field. The objective of the study is the experimental investigation of large scale astrophysical and geophysical phenomena in spherical geometry stipulated by rotation, thermal convections and radial gravity fields. These systems include earth outer core or mantle convection, differen-tial rotation effects in the sun, atmosphere of gas planets as well as a variety of engineering applications. The GEOFLOW I experimental instrument consists of an experiment insert for operation in the Fluid Science Laboratory, which is part of the Columbus Module of the ISS. It was first launched in February 2008 together ...
2010-01-01
... an endocrinologist here and am part of the Diabetes and Endocrinology Associates here at Shawnee Mission Medical ... also an endocrinologist and a member of the Diabetes and Endocrinology Associates here at Shawnee Mission Medical ...
Integrated Mission Specification and Task Allocation for Robot ...
... for team sizes ranging from 2 to 6 robots. ... intercep- tion mission, a robot must overtake a ... of unmanned underwater vehicles (UUV), unmanned aerial ...
2011-05-14
Challenges and Solutions to Producing a Useful High Resolution Soil Moisture Product
Information about surface soil moisture conditions is of critical importance to real-world applications such as agricultural production, water resource management, flood prediction, fire prediction, water supply, military mobility, etc.. Near-surface soil moisture is currently available from non-ideal sensor configuration observations, and two missions targeted at measuring near-surface soil moisture with ideal sensor configuration are expected before the end of the decade (the European Space Agency (ESA), Soil Moisture and Ocean Salinity (SMOS) mission, and the National Aeronautics and Space Administration (NASA), Hydrospheric states "Hydros" mission). Though remote sensing can make spatially comprehensive measurements of surface soil moisture, it cannot provide information on the entire land surface hydrologic system, and the measurements represent only a snap shot in time. Alternatively, land ...
2005-05-01
Radial velocities, dynamics of stars and nebulosities with GAIA and VLT-GIRAFFE
This document is divided in two parts. The first part deals with the radial velocities (RV) distributions for B-type stars and nebulosities observed with the VLT-GIRAFFE in the Large and Small Magellanic Clouds towards the open clusters NGC2004 and NGC330. Thanks to the resolution of GIRAFFE spectra, we found that the RV distribution for the nebulosities in the LMC is bi-modal. This bi-modality can be interpreted, in term of dynamics, by the expansion of the LMC4 superbubble. The second part deals with the GAIA space mission and the determination of the radial velocities by using Radial Velocity Spectrometer (RVS) spectra. The methods to determine the radial velocities are presented as well as preliminary results on simulated RVS spectra.
2008-01-01
International Nuclear Information System (INIS)
The IAEA Assessment of Safety Significant Events Team (ASSET) report presents the results of an ASSET team's assessment of their investigation of the effectiveness of the plant for prevention of incidents since 1990 at Zaporozhe nuclear power plant. The results, conclusions and suggestions presented herein reflect the views of the ASSET experts. They are provided for consideration by the responsible authorities in Ukraine. The ASSET team's views presented in this report are based on visits to the plant, on review of documentation made available by the operating organization and on discussions with utility personnel. The report is intended to enhance operational safety at Zaporozhe by proposing improvements to the policy for the prevention of incidents at the plant. The report includes, as a usual practice, the official response of the operating organization as well as of the regulatory body to the ASSET recommendations. Figs.
2003-11-01
Five Special Types of Orbits Around Mars
The abstract is additional with repect to the paper published in JGCD. Ordinary Earth satellites are usually placed into five categories of special orbits: sun-synchronous orbits, orbits at the critical inclination, frozen orbits, repeating ground track orbits, and geostationary orbits. This paper investigates their counterparts around Mars and examines the basic nature of these orbits, which are of special interest for missions conducted around Mars, including Mars reconnaissance. Mars' gravity field is much more complicated, with relatively smaller J2, compared to Earth's, which makes the behaviors of these Martian orbits different from those of Earth. Analytical formulations and numerical simulations are used to analyze these Martian orbits and compare them with their Earth counterparts. First, mean element theory is employed to describe variations of orbital elements and give the constraint conditions for achieving these special orbits. ...
2011-01-01
International Nuclear Information System (INIS)
Nuclear forensic science has become increasingly important for global nuclear security. However, many current laboratory analysis techniques are based on methods developed without the imperative for timely analysis that underlies the post-detonation forensics mission requirements. Current analysis of actinides, fission products, and fuel-specific materials requires time-consuming chemical separation coupled with nuclear counting or mass spectrometry. High-temperature gas-phase separations have been used in the past for the rapid separation of newly created elements/isotopes and as a basis for chemical classification of that element. We are assessing the utility of this method for rapid separation in the gas-phase to accelerate the separations of radioisotopes germane to post-detonation nuclear forensic investigations. The existing state of the art for thermo chromatographic separations, and its applicability to nuclear forensics, will be ...
2011-07-01
The Development of a Neutral Particle Detector for Observations of the Thermosphere
One of the least understood regions of the upper atmosphere is the thermosphere, principally due to the difficulty of making observations. The neutral atmosphere is known to be highly variable, and its composition and density varies by several orders of magnitude due to solar activity, diurnal cycles, latitude, geomagnetic activity, and gravity waves. In the past, most in-situ measurements of the neutral atmosphere have utilized detectors that are dependent on arrival angle and energy accommodation of incoming species, so that information related to nascent velocity distribution and reactive species abundances is often masked. This paper will review design concepts and laboratory tests related to the development of a novel open-ionizer, neutral particle detector for space environment measurements which can overcome these limitations. The sensor features a very large field-of-view suitable for sounding rocket missions. This time-of-flight ...
2006-12-01
Onboard Systems Record Unique Videos of Space Missions - NASA
May 1, 2011 ... Onboard Systems Record Unique Videos of Space Missions ... Corporation, An artist's rendering of LCROSS launching toward the Moon .... Station (ISS) as part of the Commercial Orbital Transportation Services program. ...
... York, 7/15/2008) Cancers Adrenal Gland Cancer Laparoscopic Adrenalectomy (Shawnee Mission Medical Center, Shawnee Mission, KS, ... MN, 1/24/2007) Colorectal Cancer Advances in Laparoscopic Colorectal Surgery (Charles E. Schmidt College of Biomedical ...
The Mission, Organization, and Functions of US Army Rear ...
... counseling, some training, and assure the general health and welfare of the command. ... publications, promotions, OERs/NCOER's (Officer Efficiency ...
1992-06-07
Saturn's Recycling Rings - Cassini Solstice Mission - NASA
Dec 12, 2007 ... This is an artist concept of a close-up view of Saturn's ring particles.
Mission losses were incurred by an early warning satellite and a Milstar-2 communications satellite when their launch vehicles malfunctioned, the first, ...
... 9 Integrated Battle Management System Data Link Architecture Common Mission Planring System MILSTAR and SATCOMs Common Aviation ...
1993-05-17
Force Protection and Mission Accomplishment in Bosnia and ...
... Khobar Towers bombing in three ways. The first was to revaluate the force posture in the Arabian Gulf region. This led to ...
2011-05-13
Abstracts by Mission Directorate - NASA
A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, ...
ALOS satellite imagery utilizations for safeguards
International Nuclear Information System (INIS)
This paper introduces examples of satellite imageries analysis and utilizations for safeguards activities. Recently, many kinds of satellite imageries are available in the world i.e., high-spatial resolution, multi- and hyper-spectral, multi-function, and multi-polarization radars. The problem is that how to obtain the required information from these digital images. The Japan Aerospace Exploration Agency (JAXA) has successfully launched the Advanced Land Observing Satellite (ALOS, the nickname is 'Daichi') on 24th January, 2006. The mission objectives are cartography, regional observation, disaster monitoring etc. ALOS has three instruments, PRISM, AVNIR-2, and PALSAR, to achieve these objectives. An overview of ALOS is provided. ALOS follows the Japanese Earth Resources Satellite- 1 (JERS-1) and the Advanced Earth Observing Satellite (ADEOS) and utilizes advanced land-observing ...
2006-10-16
Routine environmental audit of the Y-12 Plant, Oak Ridge, Tennessee
Energy Technology Data Exchange (ETDEWEB)
This report documents the results of the routine environmental audit of the Oak Ridge Y-12 Plant (Y-12 Plant), Anderson County, Tennessee. During this audit, the activities conducted by the audit team included reviews of internal documents and reports from previous audits and assessments; interviews with U.S. Department of Energy (DOE), State of Tennessee regulatory, and contractor personnel; and inspections and observations of selected facilities and operations. The onsite portion of the audit was conducted August 22-September 2, 1994, by the DOE Office of Environmental Audit (EH-24), located within the Office of Environment, Safety and Health (EH). DOE 5482.1 B, {open_quotes}Environment, Safety, and Health Appraisal Program,{close_quotes} establishes the mission of EH-24 to provide comprehensive, independent oversight of DOE environmental programs on behalf of the Secretary of Energy. The ultimate goal of EH-24 is enhancement of environmental ...
1994-09-01
Missionary education in West Africa: a study of pedagogical ambition
British Library Electronic Table of Contents (United Kingdom)
The history of the North German Mission Society (established 1836 in Hamburg) and its activity on the West African coast (from 1847 onwards among the Ewe, in what is now Ghana and Togo where it was and still is known as the 'Bremen Mission') mirrors neatly the various phases of the idea of 'mission': its composite motivation (Enlightenment, humanism and Pietism); the rejection of a narrow denominationalism (though the management of the mission was from 1850 onwards in the hands of the society's Bremen branch which belonged to the Reformed tradition); the entanglement of mission and overseas trade; the ambivalent attitude towards imperialism; the shaping of the missionary process as a profoundly educational one; the growing independence of the African church when the German missionaries wer...
2011-01-01
CRC handbook of NASA future missions and payloads
Energy Technology Data Exchange (ETDEWEB)
The author presents a detailed and quantitative description of all of the programs, systems, sensors and experiments associated with the next 30 years of space endeavors by the National Aeronautics and Space Administration. Derived from the fifth issue of the NASA Space Systems Technology Model, the missions and payloads are categorized by applications area: solar system exploration, astrophysics, earth sciences, communications, space transportation and utilization of the space environment. Far-term missions are described as opportunity missions and landmark missions, for the distant future. Technology requirements are collected by discipline: power, propulsion, materials, structures, information systems, navigation, guidance and control. Payload technology requirements are organized by instrument sensing range. This information defines in quantitative terms, the opportunities and limits for future ...
1986-01-01
Energy Technology Data Exchange (ETDEWEB)
In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major ...
1996-04-01
Ion Langmuir waves in a nonneutral plasma
Energy Technology Data Exchange (ETDEWEB)
A nonneutral /sup 7/Li/sup +/ ion plasma is described in which ion Langmuir waves are observed for the first time. The properties of these waves near the Brillouin density limit are investigated.
1981-01-05
Search for Extra-Terrestrial planets: The DARWIN mission - Target Stars and Array Architectures
The DARWIN mission is an Infrared free flying interferometer mission based on the new technique of nulling interferometry. Its main objective is to detect and characterize other Earth-like planets, analyze the composition of their atmospheres and their capability to sustain life, as we know it. DARWIN is currently in definition phase. This PhD work that has been undertaken within the DARWIN team at the European Space Agency (ESA) addresses two crucial aspects of the mission. Firstly, a DARWIN target star list has been established that includes characteristics of the target star sample that will be critical for final mission design, such as, luminosity, distance, spectral classification, stellar variability, multiplicity, location and radius of the star. Constrains were applied as set by planet evolution theory and mission architecture. Secondly, a number of alternative ...
2005-01-01
45 CFR 1703.202 - Provisions under which a meeting may be closed.
...identity of a confidential source and, in the case of...lawful national security intelligence investigation, confidential...only by the confidential source, (v) Disclose investigative...exercise its authority to open to public observation...requires that the meeting be...
2010-10-01
The magnetic spectrometer PAMELA for the study of cosmic antimatter in space
Energy Technology Data Exchange (ETDEWEB)
In the framework of the RIM (Russian Italian mission) program, PAMELA is the experiment devoted to the accurate measurement of the positron and antiproton spectra from the very low energy thresh-old of 100 MeV up to more than 50 GeV, and to hunt antinuclei with sensitivity better than 10{sup -7} in the helium/helium ratio. A permanent magnet equipped by microstrip silicon sensors, measures the particle momentum with MDR=400 GV/c on GF=25 cm{sup 2} sr. An accurate ToF system, a 19 X{sub o} deep imaging calorimeter, an aerogel Cherenkov counter and a TRD detector complement the spectrometer in order an efficient e{sup +-}/p{sup +-} separation and some light isotope identification capability. The PAMELA experiment will be carried out on a 700 km high polar orbit, on board of the Earth-observation meteor-3A satellite, to be launched at the end of 1988.
1995-09-01
Observing the Sunyaev-Zel'dovich Effect Closer to Home
Hot gas trapped in a dark matter halo will produce a decrement in the surface brightness of the microwave background, the Sunyaev-Zel'dovich (SZ) effect. While massive clusters produce the strongest central SZ decrements, we point out that a local galaxy halo, specifically the halo of M31, may be one of the brightest integrated SZ sources in the sky. For various realistic gas distributions consistent with current X-ray limits, we show that the integrated SZ decrement from M31 will be comparable to decrements already detected in more distant sources, provided its halo contains an appreciable quantity of hot gas. A measurement of this decrement would provide direct information on the mass, spatial distribution and thermodynamic state of hot gas in a low-mass halo, and could place important constraints on current models of galaxy formation. Detecting such an extended (~ 10 degree), low-amplitude signal will be challenging, but should be possible with all-sky SZ maps from satellite ...
2003-01-01
Observation of the Far-ultraviolet Continuum Background with SPEAR/FIMS
We present the general properties of the far-ultraviolet (FUV; 1370-1720A) continuum background over most of the sky, obtained with the Spectroscopy of Plasma Evolution from Astrophysical Radiation instrument (SPEAR, also known as FIMS), flown aboard the STSAT-1 satellite mission. We find that the diffuse FUV continuum intensity is well correlated with N_{HI}, 100 $\\mu$m, and H-alpha intensities but anti-correlated with soft X-ray. The strongest correlation is with the H-alpha emission, and the correlation of the diffuse background with the direct stellar flux is weaker than the correlation with other parameters. The continuum spectra are relatively flat. However, a weak softening of the FUV spectra toward some sight lines, mostly at high Galactic latitudes, is found not only in direct-stellar but also in diffuse background spectra. The diffuse background is relatively softer that the direct stellar spectrum. We also find that the diffuse FUV background averaged ...
2010-01-01
International Nuclear Information System (INIS)
The authors report on observations of plasma wave turbulence generated during electron beam injections, spacecraft potential variations, and neutral gas emissions of the CHARGE 2 sounding rocket experiment. The payload was flown in a mother/daughter configuration, with the two sub-payloads electrically connected by an insulated, conducting tether. While tethered, the two platforms were separated, drifting apart in a direction perpendicular to both the magnetic field and to the spacecraft velocity, reaching a maximum distance of 426 m at the end of the flight. The mother carried a high-voltage (HV) system (0-460 V), biasing the mother negative relative to the daughter. The operation of the HV bias system simulated the motional emf induced in larger orbiting space structures like the Tethered Satellite System 1 (TSS 1) space shuttle mission scheduled for the spring of 1992. In addition, the mother carried an electron beam accelerator (1 keV, 0-46 ...
The genesis solar-wind sample return mission
Energy Technology Data Exchange (ETDEWEB)
The compositions of the Earth's crust and mantle, and those of the Moon and Mars, are relatively well known both isotopically and elementally. The same is true of our knowledge of the asteroid belt composition, based on meteorite analyses. Remote measurements of Venus, the Jovian atmosphere, and the outer planet moons, have provided some estimates of their compositions. The Sun constitutes a large majority, > 99%, of all the matter in the solar system. The elemental composition of the photosphere, the visible 'surface' of the Sun, is constrained by absorption lines produced by particles above the surface. Abundances for many elements are reported to the {+-}10 or 20% accuracy level. However, the abundances of other important elements, such as neon, cannot be determined in this way due to a relative lack of atomic states at low excitation energies. Additionally and most importantly, the isotopic composition of the Sun cannot be determined astronomically ...
2009-01-01
Masses of Neutron Stars in High-Mass X-ray Binaries with Optical Astrometry
Determining the type of matter that is inside a neutron star (NS) has been a long-standing goal of astrophysics. Despite this, most of the NS equations of state (EOS) that predict maximum masses in the range 1.4-2.8 solar masses are still viable. Most of the precise NS mass measurements that have been made to date show values close to 1.4 solar masses, but a reliable measurement of an over-massive NS would constrain the EOS possibilities. Here, we investigate how optical astrometry at the microarcsecond level can be used to map out the orbits of High-Mass X-ray Binaries (HMXBs), leading to tight constraints on NS masses. While previous studies by Unwin and co-workers and Tomsick and co-workers discuss the fact that the future Space Interferometry Mission should be capable of making such measurements, the current work describes detailed simulations for 6 HMXB systems, including predicted constraints on all orbital parameters. We find that the ...
2010-01-01
Statistical study of pulsar rotational braking
International Nuclear Information System (INIS)
Pacini (1973) has considered basic theoretical expectations regarding the magnetic dipole radiation and unipolar induction of pulsars, taking into account observational results. The present investigation is concerned with the difference between the two braking mechanisms. Attention is also given to a statistical study involving a comparison of the two braking mechanisms with observations. The study makes use of the observational data for the distribution of apparent beamwidth, and a geometrical method. The obtained results agree with the theory of magnetic dipole radiation.
Using Multiple Unmanned Systems for a Site Security Task
Energy Technology Data Exchange (ETDEWEB)
Unmanned systems are often used to augment the ability of humans to perform challenging tasks. While the value of individual unmanned vehicles have been proven for a variety of tasks, it is less understood how multiple unmanned systems should be used together to accomplish larger missions such as site security. The purpose of this paper is to discuss efforts by researchers at the Idaho National Laboratory (INL) to explore the utility and practicality of operating multiple unmanned systems for a site security mission. This paper reviews the technology developed for a multi-agent mission and summarizes the lessons-learned from a technology demonstration.
2009-04-01
Analysis of tritium mission FMEF/FAA fuel handling accidents
Energy Technology Data Exchange (ETDEWEB)
The Fuels Material Examination Facility/Fuel Assembly Area is proposed to be used for fabrication of mixed oxide fuel to support the Fast Flux Test Facility (FFTF) tritium/medical isotope mission. The plutonium isotope mix for the new mission is different than that analyzed in the FMEF safety analysis report. A reanalysis was performed of three representative accidents for the revised plutonium mix to determine the impact on the safety analysis. Current versions computer codes and meterology data files were used for the analysis. The revised accidents were a criticality, an explosion in a glovebox, and a tornado. The analysis concluded that risk guidelines were met with the revised plutonium mix.
1997-11-18
Characteristics of inertia gravity waves associated with convection are investigated in the lower stratosphere using high-resolution radiosonde data observed from 18 June to 15 July of 2005 and 2007 in Korea. Three-dimensional ray-tracing model and reanalysis data are used to investigate the propagation and the sources of the observed waves. The observed waves associated with convections are discriminated based on the existence of convections when and where the rays reach the average height range of convective clouds. Waves observed in 2005 and 2007 show similar spectral characteristics, but wave energy in 2007 is significantly larger than in 2005. The observed waves propagate from three source regions: the northeastern, southeastern, and western regions around Korea. They show preferential propagation directions based on their sources, and ...
2011-08-01
Year 2000 Computing Issues Related to the Defense Fuels ...
... manual efforts by DESC and the Defense Finance and Accounting Service would ... in serious mission and financial impacts on DLA, DESC, the ...
1999-05-17
Waste generation and pollution prevention progress fact sheet: West Valley Demonstration Project
Energy Technology Data Exchange (ETDEWEB)
This Fact Sheet presents the mission of the West Valley Demonstration Project and information on the 1994 pollution prevention and recycling accomplishments.
1994-12-31
Waste generation and pollution prevention progress fact sheet: Savannah River Site
Energy Technology Data Exchange (ETDEWEB)
This Fact Sheet provides the mission of the Savannah River Site and information on 1994 pollution prevention and recycling accomplishments.
1994-12-31
View larger image for ISS022-E-26137 - Earth Sciences and Image ...
The Asarco-Mission complex (image left) is an active producer of copper and molybdenum (important in making steel and other metal alloys), ...
VOLUME I11 IMISSION SYSTEM PERFORMANCE - NASA Technical Report ...
Nov 8, 2010 ... Ihring Mission 11, the radiation dosimetry measurement system functioned normally and provided data on the Earth's trapped radiation belts ...
United States Space Activities - NASA
Mission losses were incurred by an early warning satellite and a Milstar-2 communications satellite when their launch vehicles malfunctioned, the first, ...
Typhoon Aere : Image of the Day - NASA Earth Observatory
Aug 25, 2004 ... The Tropical Rainfall Measuring Mission or TRMM satellite provided this image of Typhoon Aere over the western Philippine Sea as it was ...
This certifies that the face of Flat Granny ... - Face in Space - NASA
This certifies that the face of Flat Granny has flown in space aboard the Space Shuttle Discovery on mission STS-. 133 from February 24 - March 9, 2011. ...
The Role of Military Workingn> Dogs in Low Intensity Conflict
... 8 Page 15. Military working Dogs. Dogs that are required by the using DOD Component for a specific purpose, mission, or combat capability. ...
1990-02-01
Single Manager for DoD Military Working Dog Program
... C. DEFINITION Military Working Dogs. Dogs that are required by the using Dol) Component for a specific purpose, mission, or combat capability. ...
1983-09-07
Science Directed Spacecraft Autonomy for Mars Missions - detail
The rapidly growing field of remote sensing is beginning to supply massive amounts of high resolution imagery of the earth and other planets. ...
Remote Sensor Systems for Unmanned Planetary Missions
instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...
No. 292-M:11/18/94:Tandem Thrust 95, a Joint Task Force Fie
... The mission of Tandem Thrust is to employ a joint task force headquarters and appropriate forces in a realistic training exercise. ...
Navy Requirements for Controlling Multiple Off-Board Robots ...
... less humans have to do to operate a robot. ... Robots can help human operators with the increase ... important mission outlined by the UUV master plan. ...
2007-06-01
NIMH Expands Public Health Education Effort to Reach Latino Men...
health research agency, NIMH is dedicated to reducing the burden of mental and behavioral disorders through research on mind, brain, and behavior. As part of that mission, NIMH...
2011-09-24
NASA Sets Launch Dates for Remaining Space Shuttle Missions
Jul 7, 2008 ... HOUSTON -- Following a detailed, integrated assessment, NASA selected ... in the center that provides a 360-degree view around the station. ...
N8530000 - NASA Technical Report Server (NTRS)
Automated RMS operation and OMV propul sian control as in Reference Mission 1. Automated transport provisions on MPF (e.g.,. Lazy-Susan concept) ...
Jupiter Solar Mission Alternative Feasibility Study
Because of its direct energy conversion techniques, AMTEC is the front runner today. However, because these systems are now only in the preliminary design ...
Information Technology - NASA Science
Mar 15, 2011 ... Information Technology. NCCS Discover Supercomputer. Science mission data collection, analysis and simulations pose unprecedented computer ...
Space Network Ku-band service. ... Completed GLAST mission schedule and budget assessment .... Utilize Ku band SN link (TDRSS) for science data return ...
EUROPEAN SPACE AGENCY Extension of the SOHO Mission
closure of the BISON network, GOLF and VIRGO will remain the only instruments ...... Faraday Cup solar wind instrument as described in Ipavich et al (1998). ...
DARWIN mission proposal to ESA
The discovery of extra-solar planets is one of the greatest achievements of modern astronomy. There are now more than 200 such objects known, and the recent detection of planets with masses approximately 5 times that of Earth demonstrates that extra-solar planets of low mass exist. In addition to providing a wealth of scientific information on the formation and structure of planetary systems, these discoveries capture the interest of both scientists and the wider public with the profound prospect of the search for life in the Universe. We propose an L-type mission, called Darwin, whose primary goal is the study of terrestrial extrasolar planets and the search for life on them. By its very nature, Darwin advances the first Grand Theme of ESA Cosmic Vision. Accomplishing the mission objectives will require collaborative science across disciplines ranging from planet formation and atmospheres to chemistry and biology, and these disciplines will ...
2007-01-01
DARPA's Airland Battle Management Program and USAF's ...
... Accession Number : ADP005426. Title : DARPA's Airland Battle Management Program and USAF's Tactical Expert Mission Planner (TEMPLAR),. ...
1986-02-01
Cloud Computing at JPL | JPL Mission Planning and Execution
He said, I had heard of Cloud Computing when I was in grad school, but they had presentations on it at EclipseCon. I was sold that it was something that ...
CESAREAN SECTION SHAWNEE MISSION MEDICAL CENTER MERRIAM, KANSAS March 13, 2008 00:00:09 ANNOUNCER: Tonight you will experience the miracle of birth during ...
CESAREAN SECTION SHAWNEE MISSION MEDICAL CENTER MERRIAM, KANSAS March 13, 2008 00:00:09 ANNOUNCER: Tonight you will experience the miracle of birth during a live ...
Baldwin, Tony Marcel - Goddard Library Repository
Schmidlin F, Morrison B, Baldwin T, Moore P, Northam E. NASA AFRICAN MONSOON MULTIDISCIPLINARY ANALYSES MISSION: BALLOON-BORNE RADIOSONDE RESULTS FROM CAPE ...
"Z1-36453'. - NASA Technical Reports Server
nitrogen, which has always been called a nerve gas. BIOCHEMICAL PROGRAM . 4. Some of the biochemical data for the Apollo 7 to 13 missions are ...
Observation of stochastic resonance near a subcritical bifurcation
Energy Technology Data Exchange (ETDEWEB)
A hysteretic subcritical period-doubling bifurcation is observed in the nonlinear strain dynamics of a magnetostrictive oscillator. The dynamic strain response of the magnetostrictive oscillator was observed with a high-resolution fiber optic interferometer. The effects of low-frequency modulation and band-limited stochastic fluctuations on such a bifurcation are investigated. Power spectral density measurements show that for an optimal value of externally injected noise the signal-to-noise ratio of a low-frequency modulation signal is enhanced by greater than 14 dB, thus indicating the first experimental observation of stochastic resonance near a bistable period-doubling bifurcation. 10 refs., 7 figs.
1993-01-01
Leveraging limited research and development (R&D) resources in the public sector
Energy Technology Data Exchange (ETDEWEB)
Mission-directed public-sector research facilities are experiencing increasingly severe budget environments while seeing expanding missions and responsibilities. In an effort to identify research leveraging methodologies an information search was conducted in conjunction with some efforts to find the proper links to systems engineering fundamentals. The result is an initial model for use in a pre-concept/phase-1 engineering design organization, with a goal of improving the organizations performance.
1996-12-01
Initial Evaluation of USAF Security Forces Distributed Mission Training (SecForDMT).
United States Air Force security forces have a central role in force protection. Their missions include military police services, installation security, air base defense, military working dog functions, and combat arms training and maintenance. Surveys in...
2004-01-01
Energy Technology Data Exchange (ETDEWEB)
The mission of the Heavy Water portion of D Area (or 400 Area) at SRS is to purify the site inventory of heavy water for storage in the Reactor Areas for future DOE missions.
1996-01-01
A consortium of four institutions, based at Western Michigan University, was to plan a Research and Development Center on Student Testing, Evaluation, and Standards Setting. The four consortium sites are Boston College, the Dallas Independent School District, the University of Kansas, and Western Michigan University. This report is a final performance report for the planning grant made to Western Michigan University by the National Institute of Education. The first section provides a summary of the planning activities actually conducted under the grant. It includes a description of particular problems and successes, a list of participants and their affiliations, and an evaluation report for the planning project. The second section is a technical report on the Research and Development (R and D) mission for the Center. It updates the mission and strategy statement contained in the planning grant application and includes an agenda, with ...
1985-09-01
Draft Strategic Laboratory Missions Plan. Volume II
International Nuclear Information System (INIS)
This volume described in detail the Department's research and technology development activities and their funding at the Department's laboratories. It includes 166 Mission Activity Profiles, organized by major mission area, with each representing a discrete budget function called a Budget and Reporting (B ampersand R) Code. The activities profiled here encompass the total research and technology development funding of the laboratories from the Department. Each profile includes a description of the activity and shows how the funding for that activity is distributed among the DOE laboratories as well as universities and industry. The profiles also indicate the principal laboratories for each activity, as well as which other laboratories are involved. The information in this volume is at the core of the Strategic Laboratory Mission Plan. It enables a reader to follow funds from the Department's appropriation to a specific ...
2004-06-07
Energy Technology Data Exchange (ETDEWEB)
This experiment is carried out in the series of the investigation on the damage mechanism of carbon steel. In this paper, the damage situation is considered by structure observations. The test were carried out in 600degC-1200degC temperature range, in blowing an argon gas. The reagents are Na{sub 2}O, Na{sub 2}O{sub 2} and NaOH. From structure observations, the holes are observed on the surface of iron-base material in some test conditions. This result is indicated that the selective reaction occurs. The selective reaction is more obvious as the time exposed to the high temperature is longer. It is considered that the selective reaction occurs after the chemical reaction between iron-base material and sodium compound. The areas, in which Mn-concentration is higher, are observed in products on the surface of specimen. (author)
1997-07-01
NOAA ESRL Marine and Air-Sea Interaction Working Group
Climate Observations Joint Air-Sea Monsoon Investigation: JASMINE Nauru '99 NTAS PACS SHEBA STRATUS VOCALS WHOTS Data Cruises Tropical Eastern Pacific Synthesis The Research...
2011-10-15
UK PubMed Central (United Kingdom)
The purpose of this study was to investigate whether genetically determined properties of muscle metabolism contribute to the exceptional physical endurance of world-class distance runners. ATP, phosphocreatine,...Full Text Available
1988-12-01
Endurance time is joint-specific: A modelling and meta-analysis investigation
UK PubMed Central (United Kingdom)
Static task intensity–endurance time (ET) relationships (e.g. Rohmert's curve) were first reported decades ago. However, a comprehensive meta-analysis to compare experimentally-observed...Full Text Available
2010-01-01
Investigation of three red giants observed in the CoRoT seismo field
Three red giants (HD 49566 (G5III), HD 169370 (K0III) and HD 169751 (K2III)) have been observed in the CoRoT seismo field and additional ground-based spectra have been acquired. We present preliminary results of a detailed study of these stars using the observational constraints from the spectra and CoRoT data, and models from the YREC stellar evolution code.
2011-01-01
Thermal Protection Materials Technology for NASA's Exploration Systems Mission Directorate
To fulfill the President s Vision for Space Exploration - successful human and robotic missions between the Earth and other solar system bodies in order to explore their atmospheres and surfaces - NASA must reduce trip time, cost, and vehicle weight so that payload and scientific experiment capabilities are maximized. As a collaboration among NASA Centers, this project will generate products that will enable greater fidelity in mission/vehicle design trade studies, support risk reduction for material selections, assist in optimization of vehicle weights, and provide the material and process templates for development of human-rated qualification and certification Thermal Protection System (TPS) plans. Missions performing aerocapture, aerobraking, or direct aeroentry rely on technologies that reduce vehicle weight by minimizing the need for propellant. These missions use the destination planet s ...
2005-01-01
Tank waste remediation system retrieval and disposal mission key enabling assumptions
Energy Technology Data Exchange (ETDEWEB)
An overall systems approach has been applied to develop action plans to support the retrieval and immobilization waste disposal mission. The review concluded that the systems and infrastructure required to support the mission are known. Required systems are either in place or plans have been developed to ensure they exist when needed. The review showed that since October 1996 a robust system engineering approach to establishing integrated Technical Baselines, work breakdown structures, tank farm structure and configurations and work scope and costs has been established itself as part of the culture within TWRS. An analysis of the programmatic, management and technical activities necessary to declare readiness to proceed with execution of the mission demonstrates that the system, people and hardware will be on line and ready to support the private contractors. The systems approach included defining the retrieval and ...
1998-01-05
Energy Technology Data Exchange (ETDEWEB)
Experimental investigation was carried out for friction factor and heat transfer coefficient in the case of a rotating tube with a twisted-tape insert for heat transfer augmentation. The data obtained were compared with existing data for a stationary tube with a twisted-tape insert. It has been observed that the enhancement in heat transfer offsets the rise in friction factor due to rotation, with respect to a plain tube under stationary conditions. A correlation has been proposed for the data obtained.
1995-04-01
Zero-G two phase flow regime modeling in adiabatic flow
Energy Technology Data Exchange (ETDEWEB)
Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow streams. The ...
1993-01-15
Zero-G two phase flow regime modeling in adiabatic flow
International Nuclear Information System (INIS)
Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A ampersand M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow ...
1993-01-10
NPOESS Interface Data Processing Segment (IDPS) Hardware
The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and ...
2008-12-01
Energy Technology Data Exchange (ETDEWEB)
The Materials & Fuel Complex (MFC) facilities 799 Sodium Processing Facility (a single building consisting of two areas: the Sodium Process Area (SPA) and the Carbonate Process Area (CPA), 799A Caustic Storage Area, and 770C Nuclear Calibration Laboratory have been declared excess to future Department of Energy mission requirements. Transfer of these facilities from Nuclear Energy to Environmental Management, and an associated schedule for doing so, have been agreed upon by the two offices. The prerequisites for this transfer to occur are the removal of nonexcess materials and chemical inventory, deinventory of the calibration source in MFC-770C, and the rerouting and/or isolation of utility and service systems. This report provides a description of the current physical condition and any hazards (material, chemical, nuclear or occupational) that may be associated with past operations of these facilities. This information will document conditions at time of ...
2009-11-01
An integrated nuclear electro-thermal engine concept for geostationary missions
International Nuclear Information System (INIS)
A preliminary design for a nuclear electric 'Space Tug' is proposed for use in conjunction with the American Space Shuttle for high energy missions. The vehicle would employ a SNAP 10A/2 or SNAP 8 nuclear reactor derivative for its power supply and slush hydrogen as the working fluid for the electrothermal thrusters. A thermodynamic conversion cycle would be employed for electrical power generation, for which the hydrogen working fluid would perform the duty of the heat sink. The cycle would eliminate the need for heavy waste radiators and improve the overall thermal efficiency. The vehicle promises a considerable payload advantage over a chemical recoverable Tug for geostationary missions. (orig.).
1974-10-14
Energy Technology Data Exchange (ETDEWEB)
The design of a reaction cell which permits the investigation of the sorption kinetics of microcomponents without separation of the phases under automated condition has been described. The use of thin-layer inorganic sorbents obtained by depositing films of a sorbing substance from aqueous solutions on flat substrates of small thickness makes it possible to determine the extent of sorption even at small values in the case of /beta/ emitters with a low energy and /alpha/ emitters. Detailed observation of the kinetics of isotopic exchange in the CdS-/sup 115m/Cd-HNO/sub 3/ system has made it possible to reveal at least four stages in the process during the time of observation.
1988-09-01
Thermal diffusion by Brownian motion induced fluid stress
The Ludwig-Soret effect, the migration of a species due to a temperature gradient, has been extensively studied without a complete picture of its cause emerging. Here we investigate the dynamics of DNA and spherical particles sub jected to a thermal gradient using a combination of Brownian dynamics and the lattice Boltzmann method. We observe that the DNA molecules will migrate to colder regions of the channel, an observation also made in the experiments of Duhr, et al[1]. In fact, the thermal diffusion coefficient found agrees quantitatively with the experimental value. We also observe that the thermal diffusion coefficient decreases as the radius of the studied spherical particles increases. Furthermore, we observe that the thermal fluctuations-fluid momentum flux coupling induces a gradient in the stress which leads to thermal migration in both systems.
2007-01-01
Observation of dust stream formation produced by low current, high voltage cathode spots
International Nuclear Information System (INIS)
Macroparticle acceleration driven by low current, high voltage cathode spots has been investigated for potential applications ranging from micrometeoroid simulation to nanoparticle deposition/implantation. Acceleration by this process was observed to occur when nanometer and micrometer-sized particles were exposed to a high voltage pulse in the presence of a plasma discharge. The applied negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provide the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. Cathode spot behavior was also documented. The particle impact craters observed at the surface of downstream witness badges were documented using scanning electron microscopy and light microscopy. The observed impacts suggest the presence of energetic ...
2004-04-01
Universal Camouflage for the Future Warrior.
Due to increased deployments with varied missions and new technologies/advanced threats against U.S. Soldiers, a clear need arose for developing camouflage pattern(s) to enhance the Warfighter's survivability' on the modern battlefield. Based on these tec...
2004-01-01
T Plant secondary containment and leak detection upgrades
Energy Technology Data Exchange (ETDEWEB)
The W-259 project will provide upgrades to the 2706-T/TA Facility to comply with Federal and State of Washington environmental regulations for secondary containment and leak detection. The project provides decontamination activities supporting the environmental restoration mission and waste management operations on the Hanford Site.
1995-10-19
Strategic planning for information management: what are the deliverables?
UK PubMed Central (United Kingdom)
This paper describes the deliverables framework developed by Vanderbilt University Medical Center (VUMC) in its IAIMS planning process. The key deliverables include: visions for the future; mission,...Full Text Available
1995-01-01
Peter Frampton Talks to Station Crew
National Aeronautics and Space Administration (NASA)
Rocker Peter Frampton and his band are introduced by astronaut Ron Garan to Commander Mike Fossum and Flight Engineers Satoshi Furukawa and Sergei Volkov aboard the International Space Station during a visit to Mission Control in Houston.
2011-10-17
Meet the NASA Scientists and Engineers Andrea ... - Aura - NASA
Equipped with terahertz sensors, the Aura mission will see far more ... We introduce you to a few amazing individuals, all sharing the dubious title of rocket scientist . And a ..... similar thing happens with incoming light. Astronomers call it the ...
In Their Own Words: Charlie Bolden
National Aeronautics and Space Administration (NASA)
NASA Administrator Charles Bolden, who flew four space shuttle missions, talks about how space travel changed his life and how he applies his astronaut training to his work as the head of the space agency.
2011-10-19
Energy Technology Data Exchange (ETDEWEB)
With the November 1989 formation of the Office of Technology Development (OTD) within the Office of Environmental Restoration and Waste Management (EM) came the responsibility to develop programs to ensurethat enough trained and educated people would be available to support the achievement of EM's 30-year goal. This mission responsibility derives from public policy and Departmental environmental management requirements. Within DOE, urgency to move forward resulted from the assumptions (1) that the current workforce was insufficiently prepared for the transition from a production mission to a mission of environmental compliance and cleanup; and (2) that, given current trends and forecasts, the national education infrastructure was unlikely to yield the scientists, engineers, and technicians to meet future DOE workforce needs, especially in the case of women and minorities who, projected to make up two-thirds of the ...
1992-01-01
Hanford Site environmental report for calendar year 1989
Energy Technology Data Exchange (ETDEWEB)
This report is a summary of the environmental status of the Hanford Site in 1989. It includes descriptions of the Site and its mission, the status of compliance with environmental regulations, planning and activities to accomplish compliance, environmental protection and restoration activities, and environmental monitoring. 97 refs., 67 figs., 14 tabs.
1990-05-01
Gestational Hypertension and Preeclampsia
... Mission Research Local Events Advocacy Professional Resources Privacy policy Welcome Back! Use your existing or March for ... or email address Password Forgot username/password Privacy policy Welcome Back! Enter your e-mail address to ...
GSFC Information Systems Technology Developments Supporting the Vision for Space Exploration.
The Vision for Space Exploration will guide NASA's future human and robotic space activities. The broad range of human and robotic missions now being planned will require the development of new system-level capabilities enabled by emerging new technologie...
2005-01-01
Frequently Asked ... - Precipitation Measurement Missions - NASA
... say for sure if the signal is coming from hail, lots of graupel, or some other hydrometeor . ... Precipitation forms when cloud droplets or ice particles in clouds grow and .... A landslide is the movement of rock, debris, or earth down a slope. ...
Expedition crew rotation highlights upcoming shuttle mission
Feb 23, 2001 ... Florida, as an F-16 weapons separation engineer with .... new era of space-based research aboard the International Space. Station. ..... the Web at: http://www. aiaa.org/calen- dar/index.hfm?cal=1&cfp=1 ...
Discovery Dispatch - Discovery Program - NASA
funded these sensors as the first Discovery Mission of. Opportunity, part of the ... aboard a Russian Soyuz rocket. .... the Swedes on other projects, mainly sounding rocket projects. ..... incoming applications for the Fellowship Program, fielding ...
Comparison of the UHF Follow-on and MILSTAR Satellite Communication Systems.
The author compares the UHF Follow-on and MILSTAR satellite communication systems. The comparison uses an analytical hierarchy process. Although the two systems have been tasked with different missions, a comparison of cost, capability, and orbit is condu...
1991-01-01
... Author: Vets With A Mission Subjects: vietnam, vietnam war, warfare DeweyClass: 959.7043 Resource ... Subjects: vietnam, vietnam war DeweyClass: 959.7 Resource type: bibliography, index World Travel ...
8:00am - Jack Marburger's Remarks to the Committee - NASA
Aug 5, 2009 ... and the intelligence community as well. The subsequent process was carried ..... The source of this criticism ranges from concern over technical capability to .... universe with both human and robotic missions, and open ...
5 - NASA Technical Reports Server
The mission includes a reflected solar instrument retrieving at-sensor .... incoming solar radiation. This direct aerosol radiative forcing (DARF) ... examining the behavior of geosynchronous rocket bodies and non-stabilized payloads as ...
...undertake missions and tasks (on either a...Secretary of Defense to task the DoD Components...the Chairman of the Joint Chiefs of Staff any commitment of military forces assigned to the Unified... (9) Military forces employed in MSCA...approval from higher headquarters, local military...
2010-07-01
Field investigation of radio network usage at the dismounted infantry section level
The Soldier Information Requirements Technology Demonstration (SIREQ TD) project is an experimentation program to identify technologies that significantly enhance the performance of our future soldiers. One of the study series involved a 2 x 2 factorial comparison of the benefits of digital maps over paper maps, and the use of radios vs. no radios. Thirty-two Canadian regular force infantry soldiers performed force-on-force tactical assault missions in wooded terrain, with each soldier participating in all four test conditions. The radios were configured to operate in 4 subnets: 1 channel for each of the 2 Assault Groups (4 soldiers on a channel); a Section Commander/2IC channel; and an all-users channel. Note that in the no-radio conditions soldiers still operated the press-to-talk switch to allow recording of communications, but the speaker volume was set to zero. All communications were date/time stamped, identified as to the user and channel, and the audio was ...
2006-06-01
Effect of elevated temperatures on the performance of an InP cell illuminated by a selective emitter
Energy Technology Data Exchange (ETDEWEB)
The thermophotovoltaic (TPV) option was not selected for further deep space mission technology development in NASA for several reasons. Chief among them was the large radiator required to keep the photovoltaic cells at a sufficiently low operating temperature. This led to significant integration problems with the spacecraft and limited sensor view angles. It is clear that the issue of cell temperature is crucial for space applications because of radiator size and system impact. Many efforts have focused on matching cell band gap to appropriate emitters in the 1 to 2 {mu}m range, resulting in band gaps in the 0.5 to 0.8 eV range. However, low band gaps lead to low open circuit voltages ({approximately}0.25 to 0.45 V) caused by high intrinsic carrier concentrations (n{sub i}{sup 2}). Thus, in order to obtain high performance. Photovoltaic cell temperatures must be kept near room temperature. This leads to the inevitable consequence of very large radiators for space ...
1999-03-01
Robotics and teleoperator-controlled devices
International Nuclear Information System (INIS)
This paper presents a rationale for and a summary of tasks and missions to which mobile and stationary robots and other teleoperator-controlled devices could be assigned in response to the accidental release of radioactive and other hazardous/toxic materials to the environment. Many of these vehicles and devices currently support operation and maintenance of nuclear power plants and other nuclear industry facilities. This paper also discusses specific missions for these devices at the Three Mile Island and Chernobyl nuclear power plant sites at the time of the accidents. Also discussed is the status of devices under development for future applications, as well as research on robotics.
British Library Electronic Table of Contents (United Kingdom)
This forum showcases the work of a variety of different heritage-based centers, organizations, and projects dedicated to research, education, and preservation of tangible and intangible forms of cultural heritage. The descriptions of these centers demonstrate the diversity of heritage work being done today. The centers and projects described in the forum vary in their contexts, missions, and outcomes. Highlighted in the forum are preservation organizations, university-based heritage centers, and a global collaborative cultural heritage project. Each organization in the forum provides information about their missions and goals, their approaches or methods to heritage work, and a brief description of some of their initiatives.
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
In the framework of the negotiations on the climatic changes, beginning at Rio in 1992, the France received an UN conference from the 4 to 15 of september 2000. This conference determined the necessary actions for the Kyoto protocol validation. This document presents in two part the program of these days. The first part is devoted to the world government policy and the second part defines the french actions decided to fight against the climatic change. A glossary of the main terms adapted to the climatic change domain, is also provided. (A.L.B.)
2000-07-01
Energy Technology Data Exchange (ETDEWEB)
The results of an investigation on the production of Group IIA atomic and molecular negative ion beams formed in a cesium-sputter negative ion source are presented. The sputtering material was formed by pressing pellets of stoichiometric mixtures of the Group IIA element carbonates and 10% copper powder. Negative ions of several alkaline-earth elements and their oxides have been observed. Beam intensities as high as 180 pA have been observed for Sr{sup -}and 20 nA for SrO{sup -}. (orig.).
1996-09-11
International Nuclear Information System (INIS)
The results of an investigation on the production of Group IIA atomic and molecular negative ion beams formed in a cesium-sputter negative ion source are presented. The sputtering material was formed by pressing pellets of stoichiometric mixtures of the Group IIA element carbonates and 10% copper powder. Negative ions of several alkaline-earth elements and their oxides have been observed. Beam intensities as high as 180 pA have been observed for Sr"-and 20 nA for SrO"-. (orig.).
1996-09-01
Magnetic fluctuations in paramagnetic Mn{sub 0.81}Ni{sub 0.19}
Energy Technology Data Exchange (ETDEWEB)
Magnetic fluctuations present in the paramagnetic Mn{sub 0.81}Ni{sub 0.19} system have been investigated by measuring inelastic magnetic neutron scattering from a single crystal at temperatures of 450, 585 and 700 K. Antiferromagnetic correlations are observed to be present at all the temperatures studied. The spectral width of the magnetic scattering has been observed to increase with temperature, while the spatial range of the magnetic correlations is seen to decrease as the temperature is raised. The wave-vector-dependent susceptibility is found to follow a Curie-Weiss law near the (1 0 0) position, in agreement with theoretical predictions.
2006-11-15
LC-MS characterization of metoclopramide photolysis products
British Library Electronic Table of Contents (United Kingdom)
The aim of this study was to investigate the photodegradation of the antiemetic drug metoclopramide. Metoclopramide aqueous solutions were photoirradiated at 254nm under argon atmosphere. Irradiated metoclopramide solutions were analyzed by high performance liquid chromatography-ion trap mass spectrometry in order to characterize photolysis products. Rapid decrease in metoclopramide purity, following first-order kinetic, was observed following irradiation. The structures of 18 photolysis products were tentatively identified based on their mass spectra and fragmentation. The main degradation mechanism was scission of the chlorine which could be followed by polymerization of the resulting products since dimeric and trimeric products were observed.
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
The transformation of Pd/Si to Pd{sub 2}Si/Si is investigated using depth-resolved positron annihilation, x-ray diffraction and Auger electron spectroscopy studies. The observed defect-sensitive positron S-parameter value of 1.022-1.054 indicates the existence of divacancies across the silicide/silicon interface and Si substrate region. Our experimental observation of vacancy defects is consistent with the model proposed for excess vacancy generation across the interface consequent to Si diffusion. (letter to the editor)
2003-11-26
The electron-capture processes of highly stripped ions of Fq+ (q=6,7,8) and Neq+ (q=7,8,9) in collisions with He atom were investigated using the energy-gain spectroscopy technique. A single dominant peak is observed in most of the energy-gain spectra except for the Ne7+ and Ne9+ spectra, in which two peaks are observed corresponding to the one-electron capture process into levels with different principal quantum number n.
1984-03-01
Effects of top-quark anomalous decay couplings at {gamma}{gamma} colliders
Energy Technology Data Exchange (ETDEWEB)
Most general tbW couplings were investigated in the process {gamma}{gamma} {yields} tt-bar {yields} l{sup {+-}}X for unpolarized photon beams. The double angular and energy distribution of the lepton was calculated and an optimal-observable analysis on it was carried out for the SM tt-bar production mechanism. It was also shown that the leptonic angular distribution is insensitive to non-standard tbW vertex. That means that observation of non-standard effects indicates existence of some new physics in the production part.
2002-11-01
Effects of top-quark anomalous decay couplings at #gamma##gamma# colliders
International Nuclear Information System (INIS)
Most general tbW couplings were investigated in the process #gamma##gamma# #-># tt-bar #-># l"#+-#X for unpolarized photon beams. The double angular and energy distribution of the lepton was calculated and an optimal-observable analysis on it was carried out for the SM tt-bar production mechanism. It was also shown that the leptonic angular distribution is insensitive to non-standard tbW vertex. That means that observation of non-standard effects indicates existence of some new physics in the production part.
2002-11-01
Spatial fluorescence cross correlation spectroscopy by means of a spatial light modulator
Spatial Fluorescence Cross Correlation Spectroscopy is a rarely investigated version of Fluorescence Correlation Spectroscopy, in which the fluorescence signals from differ-ent observation volumes are cross-correlated. In the reported experiments, two observation volumes, typically shifted by a few $\\mu$m, are produced, with a Spatial Light Modulator and two adjustable pinholes. We illustrated the feasibility and potentiality of this technique by: i) measuring molecular flows, in the range 0.2 - 1.5 $\\mu$m/ms, of solutions seeded with fluorescent nanobeads or rhodamine molecules (simulating active transport phenomenons); ii) investigating the perme-ability of phospholipidic membrane of Giant Unilamellar Vesicles versus hydrophilic or hydrophobic molecules (in that case the laser spots were set on both sides of the mem-brane). Theoretical descriptions are proposed together with a discussion about FCS ...
2008-01-01
Lorentz transmission electron microscopy investigation of magnetically patterned Co/Pt multilayers
Energy Technology Data Exchange (ETDEWEB)
The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5-6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.
2000-08-01
1991 ice jamming along the Saint John River: a case study
Energy Technology Data Exchange (ETDEWEB)
Field investigations of major and damaging ice jamming on the Saint John River at Dickey, Maine , and at Sainte-Anne de-Madawaska, New Brunswick, in 1991, were described. The investigations included measurement of water surface profiles and shear wall heights at both sites. The measurements were supplemented by information from local observers and data collection agencies. Using a simplified equilibrium analysis, ice jam thickness and water level at the Dickey site was found to be generally in agreement with observed values. At Sainte-Anne-de-Madawaska sufficient data was obtained to construct and calibrate the numerical model RIVJAM which determined the configuration of the jam in nonequilibrium reaches. Use of the model enabled the successful reproduction of a measured water profile along the jam and the prediction of the approximate thickness of the jam, which was generally less than the measured ...
1996-04-01
Energy Technology Data Exchange (ETDEWEB)
The general objective of this workshop is to investigate and discuss methods by which uncertainties in mass balance models for toxics in the Great Lakes may be reduced. As described by the workshop prospectus, this paper is focused on problems of reducing (and quantifying) uncertainty as they relate to in situ field observations/system response measurements for the establishment of initial conditions, boundary conditions, calibration/confirmation data sets, and model post-audit data sets.'' I have taken this description to refer not only to the evaluation of uncertainty in the field observations themselves, but also to the uncertainty associated the analyses of in situ observations as they interact in the overall modeling process. Thus, I will be concerned here with quantification and reduction of uncertainty both (1) as they may be applied to descriptions of the system that is being ...
1991-01-01
One-electron reduction of chloroperoxidase by radiolytically generated electrons
Energy Technology Data Exchange (ETDEWEB)
Upon irradiation of aqueous ethylene glycol/water solutions of native chloroperoxidase (CPO) with {sup 60}Co-gamma rays at 77K one observes the one-electron reduction of the enzyme active site by radiolytically generated thermolyzed electrons. In the present study the first absorption spectrum of a low-spin ferrous form of CPO is reported which has peaks at 438, 532 and 563 nm, similar to those observed previously for cytochrome P-450. All previously described ferrous forms of CPO are high spin. In order to observe the final results of the CPO reaction with electrons, the spectral changes of native enzyme after room temperature-gamma-irradiation have also been investigated. Evidence of changes is also presented probably connected with disruption of the tertiary structure of enzyme, correlated with decrease of enzyme activity.
1990-05-16
One-electron reduction of chloroperoxidase by radiolytically generated electrons
International Nuclear Information System (INIS)
Upon irradiation of aqueous ethylene glycol/water solutions of native chloroperoxidase (CPO) with "6"0Co-gamma rays at 77K one observes the one-electron reduction of the enzyme active site by radiolytically generated thermolyzed electrons. In the present study the first absorption spectrum of a low-spin ferrous form of CPO is reported which has peaks at 438, 532 and 563 nm, similar to those observed previously for cytochrome P-450. All previously described ferrous forms of CPO are high spin. In order to observe the final results of the CPO reaction with electrons, the spectral changes of native enzyme after room temperature-gamma-irradiation have also been investigated. Evidence of changes is also presented probably connected with disruption of the tertiary structure of enzyme, correlated with decrease of enzyme activity.
1990-05-01
Luminescence properties of Ca- and Yb-codoped SiAlON phosphors
International Nuclear Information System (INIS)
Luminescence properties of SiAlON phosphors codoped with Ca and Yb were investigated by changing the host lattice composition. These modifications of the host lattice were obtained by replacing Si-N bonds by Al-N and Al-O bonds. Their photoluminescence (PL) and cathodoluminescence (CL) properties were measured and compared with each other. PL allows observing the influence of the host lattice modifications by measuring wider areas. CL can excite all luminescent centers, in particular the UV luminescence centers, even if their amount is small. Thus, two additional peaks in the ultraviolet and infrared regions were observed in CL, which is not observed by PL. This work suggests that the combination of PL and CL gives more understanding about the luminescence of SiAlON phosphors, in particular the role of the secondary phases on their properties.
2008-01-15
Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET
Energy Technology Data Exchange (ETDEWEB)
During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.
1994-07-01
Influence of weather on the behaviour of outdoor-wintered beef cattle in Scandinavia
British Library Electronic Table of Contents (United Kingdom)
The aim of the present investigation was to study the effect of weather and available protection on the behaviour of outdoor-wintered beef cattle (Bos taurus). A herd of 78-85 cattle head was studied during four winter months in the Southwest of Sweden. Protection was offered by coniferous forest situated on and around the 12ha pasture, which we divided into protection categories. During 240h we observed 10 cows and 10 heifers as focal animals (each 3h/month) during day time and adjusted observation times to the altitude of the sun. Close to the animals and at an unprotected spot of the pasture we measured temperature, wind speed and solar radiation and combined these variables to a single measure called Wind Chill Temperature (WCT). During observations the animals were in the forest in 12...
2011-01-01
We present high-precision time-series photometry of the classical delta Scuti star HD 144277 obtained with the MOST (Microvariability and Oscillations of STars) satellite in two consecutive years. The observed regular frequency patterns are investigated asteroseismologically. HD 144277 is a hot A-type star that is located on the blue border of the classical instability strip. While we mostly observe low radial order modes in classical delta Scuti stars, HD 144277 presents a different case. Its high observed frequencies, i.e., between 59.9c/d (693.9 microHz) and 71.1c/d (822.8microHz), suggest higher radial orders. We examine the progression of the regular frequency spacings from the low radial order to the asymptotic frequency region. Frequency analysis was performed using Period04 and SigSpec. The results from the MOST observing runs in 2009 and 2010 were compared to each other. ...
2011-01-01
We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu W through the angular and energy spectrum of the secondary leptons. Within the narrow-width approximation, a semi-analytical study of the secondary lepton energy-angle double distribution is considered. Utility of observables derived from this is demonstrated by considering the anomalous coupling, delta-kappa-gamma. Results of our investigation for typical ILC machine considered at Ecm = 300-1000 GeV re-affirms potential of this collider as a precision machine.
2011-01-01
SRP Baseline Hydrogeologic Investigation, Phase 3
Energy Technology Data Exchange (ETDEWEB)
The SRP Baseline Hydrogeologic Investigation was implemented for the purpose of updating and improving the knowledge and understanding of the hydrogeologic systems underlying the SRP site. Phase III, which is discussed in this report, includes the drilling of 7 deep coreholes (sites P-24 through P-30) and the installation of 53 observation wells ranging in depth from approximately 50 ft to more than 970 ft below the ground surface. In addition to the collection of geologic cores for lithologic and stratigraphic study, samples were also collected for the determination of physical characteristics of the sediments and for the identification of microorganisms.
1988-08-01
Energy Technology Data Exchange (ETDEWEB)
Since 1983, about 600 research projects received a total of DM 250 million public funds for the following tasks: - Development of scientific fundamentals for monitoring and observation of forest decline and its ecological and economic consequences. - Investigation of the cause-effect relationship of forest damage, with particular regard to the involvement of the various compartments of the forest ecosystem and to the contribution of different pollutants. - Development of the scientific fundamentals required for forestry measures to accompany the air pollution abatement measures. The investigations comprised both laboratory and field tests. The findings and conclusion are summarized. (orig./MG).
1988-12-01
Considerations for the next Compton telescope mission
International Nuclear Information System (INIS)
A high resolution Compton telescope has been identified by the Gamma Ray Astronomy Program Working Group (GRAPWG) as the highest priority major mission in gamma ray astrophysics following GLAST. This mission should provide 25-100 times improved sensitivity, relative to CGRO and INTEGRAL, for MeV gamma ray lines. It must have good performance for narrow and broad lines and for discrete and diffuse emissions. Several instrumental approaches are being pursued to achieve these goals. We discuss issues relating to this mission including alternative detector concepts, instrumental configurations, and background reduction techniques. We have pursued the development of position-sensitive solid-state detectors (Ge, Si) for a high spectral resolution Compton telescope mission. A #approx#1 m2 germanium Compton telescope of position-sensitive germanium detectors was the basis for one of the GRAPWG concepts. ...
2000-04-12
International Nuclear Information System (INIS)
The investigation of important wear processes in the railway technique, especially the differentiation of the parameters influencing the wear process, requires extensive test programmes and thus high resolving methods to determine the wear. Radiometric methods enable considerably greater measuring accuracy with the help of the activation of materials than an observation of measurement or measuring changes. (orig./LH).
1975-04-03
Theory of bistability in the face-pumped laser with bimolecular recombination
Steady-state and transient behavior of the longitudinally pumped semiconductor laser is theoretically investigated by using a rate-equation model with distributed gain and photon density. Conditions necessary for bistable operation are derived. Dependencies of such major switching characteristics as turn-on and turn-off powers, delay, and rise times on laser parameters are examined. Influences of spontaneous radiation, impurities, and Auger recombination are studied. The results offer an explanation for the observed nonlinear behavior of face-pumped lasers.
1987-01-01
The formation of counterrotating cores in elliptical galaxies
International Nuclear Information System (INIS)
The mechanism proposed by Kormendy (1984) for the formation of counterrotating cores in elliptical galaxies is investigated using self-consistent numerical simulations of mergers between a high- and a low-luminosity elliptical galaxies. The conditions for a counterrotation to appear are determined, observational properties of the remnants are described, and the evolution of the structural and kinematic parameters of the larger galaxy is analyzed. It is shown that a counterrotation results only when the merging orbits are retrograde, due to a large change in the secondary spin during the merger. 36 refs.
Strong WW scattering at photon linear colliders
Energy Technology Data Exchange (ETDEWEB)
We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma}{yields}ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson. ((orig.)).
1995-02-01
Strong WW scattering at photon linear colliders
Energy Technology Data Exchange (ETDEWEB)
We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma} {yields} ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson.
1994-06-01
Radioprotective effect of fish products
International Nuclear Information System (INIS)
New fish cans were prepared in the Institute of Fish Industry, Burgas (BG), containing pectin and additives. A biological experimental study was conducted to investigate the decontaminating effect of the new products. The results demonstrated no decontaminating effect in relation to radiocesium and radiostrontium. A pronounced prophylactic effect was observed in case of external irradiation, judged by endogenous spleen colonies. (author).
1993-12-02
PWR FISSION PRODUCT ACTIVITY LEVELS
Recent radiochemical investigations of the PWR reactor coolant have corfirmed earlier observations that the level of activities of 33 m Cs/sup 138/, 2.8 hr Kr , and 8.1 day 1/sup 131/ are more than ten times higher than those predicted for the estimated U contamination of the Zircaloy cladding. The present fission product activity levels have not, as yet, presented any problems in the PWR. (W.L.H.)
1958-05-01
International Nuclear Information System (INIS)
Mutual influence of phosphorus and carbon on the tendency to integranular corrosion (IGC) of tempered austenitic stainless steels in boiling solutions of 65% HNO_3 and 27% of HNO_3+40 g/l Cr"6"+ was investigated. It is ascertained that under the action of carbon additions susceptibility of phosphorus-containing steels to IGC increases considerably in pure nitric acid and decreases in nitric acid containing the oxidant. Possible reasons for the effects observed are discussed.
1990-01-01
Energy Technology Data Exchange (ETDEWEB)
The long-range correlation properties in the hourly time variability of geochemical signals measured in a 70 m depth well at Triponzo (Umbria region), are investigated by the detrended fluctuation analysis (DFA). DFA is a data processing method that allows for the detection of scaling behaviors in observational time series even in the presence of non-stationarities. The procedure adopted has allowed for the unambiguous identification of possible correlations among the recorded signals and local earthquakes.
2004-07-01
Intrinsic and extrinsic crossluminescence in ionic crystals
Energy Technology Data Exchange (ETDEWEB)
Intrinsic crossluminescence (CRL) of CsBr, CsCl, and of BaF{sub 2} was investigated with electron-beam and synchrotron radiation excitation. From the CRL spectra, the excitation spectra and the reflectivity, energy level schemes were deduced. Extrinsic CRL was observed changing either the initial (CsCl:Br{sup -}) or the final (RbCl:Cs{sup +}; KCl:Cs{sup +}) state of CRL by doping. (author).
1991-01-01
Intrinsic and extrinsic crossluminescence in ionic crystals
International Nuclear Information System (INIS)
Intrinsic crossluminescence (CRL) of CsBr, CsCl, and of BaF_2 was investigated with electron-beam and synchrotron radiation excitation. From the CRL spectra, the excitation spectra and the reflectivity, energy level schemes were deduced. Extrinsic CRL was observed changing either the initial (CsCl:Br"-) or the final (RbCl:Cs"+; KCl:Cs"+) state of CRL by doping. (author).
1990-09-03
Energy Technology Data Exchange (ETDEWEB)
The influence of MeV electrons irradiation on the gate oxide layers of hydrogenated polysilicon thin film transistors (TFTs) was investigated by measuring gate leakage currents and threshold voltages. The experimental data revealed a decrease of oxide trap density and increase of positive oxide charge. Improvement in the interface roughness and in the oxide quality near the bottom interface was observed.
2006-02-15
International Nuclear Information System (INIS)
The influence of MeV electrons irradiation on the gate oxide layers of hydrogenated polysilicon thin film transistors (TFTs) was investigated by measuring gate leakage currents and threshold voltages. The experimental data revealed a decrease of oxide trap density and increase of positive oxide charge. Improvement in the interface roughness and in the oxide quality near the bottom interface was observed.
2006-02-01
Evolution of a horizontal branch Population II star with total mass 0.63 Msub solar
The theoretical evolution of a horizontal branch star of Population II is followed through the helium burning in the core phase and is compared with the results given by other investigators. The m- fluence of different physics and interpolation schemes in the opacity tables is discussed. Some thoughts are given on the explanation of the erratic period variations observed in some of the RR Lyrae variables in the globular clusters. (auth)
1973-01-01
Energy Technology Data Exchange (ETDEWEB)
The electrochemical oxidation as a method to destroy drug residues like Aspirin {sup trademark}, tetracycline or gentamicin in water was investigated with C-Anode (modified by manganese oxides) and Pt Anode. The mechanism of Aspirin {sup trademark} and tetracycline oxidation and the influence of the biocide effect was observed using GC-MS and three different microbiological tests. In general the biological availability increases with progressive oxidation of the antibiotics. (orig.)
2003-07-01
Effect of ultrasonic energy on Mn-Zn ferrite powder behavior
Energy Technology Data Exchange (ETDEWEB)
Effect of ultrasonic-wave irradiation on the Mn-Zn ferrite powder suspension prepared by solid-state reaction and alcoholic dehydration methods was investigated. Size, distribution, and morphology of the powders prepared at different temperatures were examined, as a function of irradiation time. It was observed that the powders were reduced in size by ultrasonic energy through distinct routes. 8 refs., 7 figs., 1 tab.
1999-07-01
Determination of the /sup 242m/Am nuclear moments
Energy Technology Data Exchange (ETDEWEB)
The hyperfine structure of Am atoms was investigated in an atomic beam by laser spectroscopy. The observed splittings were evaluated with respect to the magnetic dipole and electric quadrupole moments of /sup 242m/Am. The results are: ..mu../sub I/(/sup 242m/Am) = +0.97(5) nm, Q(/sup 242m/Am) = +6.5(2.0) b.
1988-07-01
Current applications of magnetic resonance in coal liquefaction research
Energy Technology Data Exchange (ETDEWEB)
Some applications of magnetic resonance in coal liquefaction research described briefly are: (1) investigation of the nature of carbon deposits on used coal-liquefaction catalysts, (2) determination of the fate of hydrogen during coal liquefaction, and (3) observation of transient free radicals during coal pyrolysis. The first two applications make use of cross-polarization /sup 13/C magnetic resonance combined with magic angle spinning, and the third application is an electron spin resonance study. (BLM)
1982-01-01
Coir fibre toxicity: in vivo and in vitro studies.
The biological activity of coir fibre, coir ash and their components were investigated in vitro by measuring the haemolytic activity and macrophage cytotoxicity. In vivo studies carried out by injecting guinea pigs intratracheally with coir fibres resulted in resolving granulomas. The observed haemolytic activity and macrophage cytotoxicity was more marked with coir ash compared with coir fibres. Chemical analysis of coir ash revealed the presence of toxic chemical constituents in appreciable amounts. PMID:6283694
1982-03-01
Carbide transformations in a gamma/gamma-prime nickel alloy during prolonged aging
Energy Technology Data Exchange (ETDEWEB)
Carbide reactions occurring in a precipitation-hardening gamma/gamma-prime Ni-Cr alloy during prolonged high-temperature aging are investigated experimentally. It is found that the decomposition of primary MC carbides, which is accompanied by the precipitation of M23C6 particles, may lead to void nucleation and growth. The effect of carbide transformations on the residual properties of the material at temperatures above the equicohesion temperature is observed at the late stages of aging only. 6 references.
1988-08-01
Boron uphill diffusion during ultrashallow junction formation
International Nuclear Information System (INIS)
The recently observed phenomenon of boron uphill diffusion during low-temperature annealing of ultrashallow ion-implanted junctions in silicon has been investigated. It is shown that the effect is enhanced by preamorphization, and that an increase in the depth of the preamorphized layer reduces uphill diffusion in the high-concentration portion of boron profile, while increasing transient enhanced diffusion in the tail. The data demonstrate that the magnitude of the uphill diffusion effect is determined by the proximity of boron and implant damage to the silicon surface.
2003-05-26
Explosive performance on the non-proliferation experiment
Energy Technology Data Exchange (ETDEWEB)
The non-proliferation experiment, originally called the chemical kiloton experiment, was planned and executed by Lawrence Livermore National Laboratory to investigate the seismic yield relationship and distinguishing seismic signals between a nuclear event and a large mass conventional explosion. The Los Alamos National Laboratory planned and conducted experiments to further their studies of the source function for signals observed seismically. Since all investigations were contingent on the performance of the emplaced chemical explosive, an array of diagnostic measurements was fielded in the emplaced explosive. The CORRTEX system was used to investigate the explosive initiation and to determine the detonation velocities in multiple levels and in numerous directions. A description of the CORRTEX experiments fielded, a review of the data obtained and some interpretations of the data are reported.
1994-03-01
Dewatering press liquor derived from orange production by forward osmosis
British Library Electronic Table of Contents (United Kingdom)
In this investigation, a forward osmosis (FO) dewatering process is evaluated as an alternative for dewatering orange peel press liquor. The press liquor is concentrated by removing water via osmosis into a concentrated ''draw solution'' across a polymeric cellulose acetate membrane. For this investigation, the draw solution consisted of sodium chloride at two different concentrations (2M and 4M). These draw solutions were used to concentrate synthetic press liquor. Concentration factors up to 3.7 resulted when using a 4M NaCl draw solution and the synthetic press liquor. Also during this investigation, fouling behavior was observed and the mechanisms of fouling elucidated through a systematic approach. This approach identified the key components of the press liquor that were primarily res...
2011-01-01
Study of the Smith-Purcell effect in the relativistic regime
International Nuclear Information System (INIS)
We propose to investigate the spontaneous emission of radiation arising out of the interaction of a relativistic electron beam with a metallic grating (the Smith-Purcell effect). The work will concentrate, primarily, in the 50-120 #mu#m part of the infrared spectrum and will be an extension of the work begun by the Oxford-Dartmouth-Essex collaboration; one of the early objectives of the project will be to develop a quantitative understanding of the power spectrum of the emitted radiation over a wide range of emission angles. In particular, the limits of relativistic peaking of forward directed emission will be investigated. The electron beam will be produced by laser irradiation of a metallic cathode in the terminal of a small Van de Graff accelerator located in the Technische Universitaet, Muenchen. Beam energies will be in the range of 2 - 4 MeV. Initial tests on photoproduction of electrons have yielded 10 mA pulses with a width of about 20 ...
1995-08-21
Solar-powered unmanned aerial vehicles
Energy Technology Data Exchange (ETDEWEB)
An analysis was performed to determine the impact of various power system components and mission requirements on the size of solar-powered high altitude long endurance (HALE)-type aircraft. The HALE unmanned aerial vehicle (UAV) has good potential for use in many military and civil applications. The primary power system components considered in this study were photovoltaic (PV) modules for power generation and regenerative fuel cells for energy storage. The impact of relevant component performance on UAV size and capability were considered; including PV module efficiency and mass, power electronics efficiency, and fuel cell specific energy. Mission parameters such as time of year, flight altitude, flight latitude, and payload mass and power were also varied to determine impact on UAV size. The aircraft analysis method used determines the required aircraft wing aspect ratio, wing area, and total mass based on maximum endurance or minimum ...
1996-12-31
International Nuclear Information System (INIS)
Extra-terrestrial exploration and development missions of the next century will require reliable, low-mass power generation modules of 100 kW_e and more. These modules will be required to support both fixed-base and manned rover/explorer power needs. Low insolation levels at and beyond Mars and long periods of darkness on the moon make solar conversion less desirable for surface missions. For these missions, a closed Brayton cycle energy conversion system coupled with a reactor heat source is a very attractive approach. The authors conducted parametric studies to assess optimized system design trends for nuclear-Brayton systems as a function of operating environment and user requirements. The inherent design flexibility of the closed Brayton cycle energy conversion system permits ready adaptation of the system to future design constraints. This paper describes a dramatic contrast between system designs requiring man-rated ...
1990-08-12
Beyond Ada - generating Ada code from equational specifications
Energy Technology Data Exchange (ETDEWEB)
Real-time mission-oriented embedded systems are much more difficult to design than ordinary software systems. They require highly reliable and efficient implementations to satisfy mission and time constraints imposed by the applications. The Ada language was designed to facilitate real-time-system software development. However, for many programmers the size and complexity of Ada itself are of concern. In the assertive programming paradigm, computations are specified as sets of assertions about properties of the solution, and not as a sequence of procedural steps. Solving procedures are automatically generated from the assertive description. Real-time programming for mission-oriented systems is supported by equational languages in which assertions are expressed as algebraic equations. Programs written in equational languages are concise, free from implementation details, and easily amenable to verification and parallel ...
1987-01-01
Research on Dynamic Neutron Radiography in HANARO
Energy Technology Data Exchange (ETDEWEB)
Neutron radiography is a non-destructive test method to examine a material by using the dependency of neutron attenuation on the nuclear characteristics of the atoms composing the object material. There are two categories of neutron radiography; static neutron radiography and dynamic neutron radiography. The static neutron radiography is a technique to observe a standing object by using a camera or a film cassette. The dynamic neutron radiography(DNR) is a technique to observe a moving object usually by using a camera. Depending on the camera frame rate, the dynamic neutron radiography is categorized into the real time neutron radiography(RTNR) and the high speed neutron radiography(HSNR). The frame rate for RTNR is 30 frames/s and that for HSNR is usually more that 500 frames/sec. Thus, RTNR is good for observing time-averaged phenomena and HSNR is good for observing instantaneous phenomena. DNR is a ...
2005-07-01
Research on Dynamic Neutron Radiography in HANARO
International Nuclear Information System (INIS)
Neutron radiography is a non-destructive test method to examine a material by using the dependency of neutron attenuation on the nuclear characteristics of the atoms composing the object material. There are two categories of neutron radiography; static neutron radiography and dynamic neutron radiography. The static neutron radiography is a technique to observe a standing object by using a camera or a film cassette. The dynamic neutron radiography(DNR) is a technique to observe a moving object usually by using a camera. Depending on the camera frame rate, the dynamic neutron radiography is categorized into the real time neutron radiography(RTNR) and the high speed neutron radiography(HSNR). The frame rate for RTNR is 30 frames/s and that for HSNR is usually more that 500 frames/sec. Thus, RTNR is good for observing time-averaged phenomena and HSNR is good for observing instantaneous phenomena. DNR is a ...
2005-10-27
Irradiation hardening of reduced activation martensitic steels
International Nuclear Information System (INIS)
Irradiation response on the tensile properties of 9Cr-2W steels has been investigated following FFTF/MOTA irradiations at temperatures between 646 and 873 K up to doses between 10 and 59 dpa. The largest irradiation hardening accompanied by the largest decrease in the elongation is observed for the specimens irradiated at 646 K at doses between 10 and 15 dpa. The irradiation hardening appears to saturate at a dose of around 10 dpa at the irradiation temperature. No hardening but softening was observed in the specimens irradiated at above 703 K to doses of 40 and 59 dpa. Microstructural observation by transmission electron microscope (TEM) revealed that the dislocation loops with the a left angle 100 right angle type Burgers vector and small precipitates which were identified to be M_6C type carbides existed after the irradiation at below 703 K. As for the void formation, the average size of voids ...
High variability in Vela X-1: giant flares and off states
We investigate the spectral and temporal behavior of the high mass X-ray binary Vela X-1 during a phase of high activity, with special focus on the observed giant flares and off states. INTEGRAL observed Vela X-1 in a long almost uninterrupted observation for two weeks in 2003 Nov/Dec. The data were analyzed with OSA 7.0 and FTOOLS 6.2. We derive the pulse period, light curves, spectra, hardness ratios, and hardness intensity diagrams, and study the eclipse. In addition to an already high activity level, Vela X-1 exhibited several intense flares, the brightest ones reaching a maximum intensity of more than 5 Crab in the 20-40 keV band and several off states where the source was no longer detected by INTEGRAL. We determine the pulse period to be 283.5320+/-0.0002 s, which is stable throughout the entire observation. Analyzing the eclipses provided an improvement in the ephemeris. ...
2008-01-01
Venus surface power and cooling systems
British Library Electronic Table of Contents (United Kingdom)
A mission to the surface of Venus would have high scientific value, but most electronic devices and sensors cannot operate at the 450degreeC ambient surface temperature of Venus. Power and cooling systems were analyzed for Venus surface operation. A radioisotope power and cooling system was designed to provide electrical power for a probe operating on the surface of Venus. For a mission duration of substantial length, the use of thermal mass to maintain an operable temperature range is likely impractical, and active refrigeration may be required to keep components at a temperature below ambient. Due to the high thermal convection of the high-density atmosphere, the heat rejection temperature was assumed to be at a 500degreeC radiator temperature, 50degreeC above ambient. The radioisotope S...
2007-01-01
The engineering institute of Los Alamos National Laboratory
Energy Technology Data Exchange (ETDEWEB)
Los Alamos National Laboratory (LANL) and the University of California, San Diego (UCSD) have taken the unprecedented step of creating a collaborative, multi-disciplinary graduate education program and associated research agenda called the Engineering Institute. The mission of the Engineering Institute is to develop a comprehensive approach for conducting LANL mission-driven, multidisciplinary engineering research and to improve recruiting, revitalization, and retention of the current and future staff necessary to support the LANL' s national security responsibilities. The components of the Engineering Institute are (1) a joint LANL/UCSD degree program, (2) joint LANL/UCSD research projects, (3) the Los Alamos Dynamic Summer School, (4) an annual workshop, and (5) industry short courses. This program is a possible model for future industry/government interactions with university partners.
2008-01-01
Report on definitional mission: Hungary gas-fired power plants. Export trade information
Energy Technology Data Exchange (ETDEWEB)
The U.S. Trade and Development Program (TDP) had received a request from the Hungarian Electricity Board (MVMT) for assistance in support of a feasibility study program to: (1) install new generation capability based on gas/oil fired combined cycle power plants, and (2) retrofit/refurbish a number of aging coal and oil fired steam plants. A Definitional Mission (DM) recommends that TDP fund the requested feasibility studies for new gas/oil fired combined cycle capabilities discussed in the Terms of Reference (TOR). Hungary will need to install significant new power capacity between now and the end of the century. Gas/oil fired combined cycle plants present probably the only option to install capacity rapidly. There is an opportunity for U.S. firms to supply technology and services with respect to these advanced power generation technologies.
1991-02-28
International Nuclear Information System (INIS)
This paper reviews the state of the art of silicon-germanium technology and assesses the problems of building thermoelectric modules in Europe, based upon silicon-germanium alloys, for use in multihundred watt radio-isotope thermoelectric generator. The generator developed in the United States for the International Solar Polar mission has been used as a reference system. The essential features of an alternative system, which employs thermocouples fabricated from improved silicon-germanium alloys based upon a design by the Fairchild Space and Electronics Company, is also described. It is concluded that although the fabrication of reliable electrical contacts will present a major problem, the technology is available in Europe to build thermoelectric modules similar to those developed for the International Solar Polar mission. (orig.).
Particle and X-ray damage in pn-CCDs
Energy Technology Data Exchange (ETDEWEB)
The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.
2000-01-11
Health and Safety Research Division progress report for the period April 1, 1987--September 30, 1988
Energy Technology Data Exchange (ETDEWEB)
The mission of the Health and Safety Research Division (HASRD) is to provide a sound scientific basis for the measurement and assessment of human health impacts of radiological and chemical substances. Our approach to fulfilling this mission is to conduct a broad program of experimental, theoretical, and field research based on a strong foundation of fundamental physical studies that blend into well-established programs in life sciences. Topics include biomedical screening techniques, biological and chemical sensors, risk assessment, health hazards, dosimetry, nuclear medicine, environmental pollution monitoring, electron-molecule interactions, interphase physics, surface physics, data base management, environmental mutagens, carcinogens, and tetratogens.
1989-03-01
Federal Geothermal Research Program Update Fiscal Year 1999
Energy Technology Data Exchange (ETDEWEB)
The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal and Wind Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office of Geothermal and Wind Technologies. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 1999. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal and Wind Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed ...
2004-02-01
Western Area Power Administration (Western) is a power marketing agency of the US Department of Energy, with jurisdiction in 15 western states. The Salt Lake City Area (SLCA) of Western performs the agency`s mission in parts of Colorado, New Mexico, Texas, Utah, Arizona, Wyoming, and Nevada. As part of its mission, Western owns, operates, and maintains a system of transmission lines for transmitting bulk electrical energy from points of generation to and between delivery points. Part of that system in southwestern Colorado includes the Blue Mesa-Curecanti and Blue Mesa-Salida 115-kV transmission lines. Western proposes to conduct maintenance and improve its access roads for these two transmission lines. This paper discusses the impacts to the existing environment as well as the environmental consequences resulting from the maintenance and construction that is proposed.
1993-07-01
Cleaning up DOE`s weapons sites: Issues of organization and management
Energy Technology Data Exchange (ETDEWEB)
Many Department of Energy facilities across the United States are seriously contaminated with radioactive and other hazardous wastes. Decades of focus on weapons production and inadequate attention to long-term solutions for dealing with those wastes have resulted in tremendous problems. The Department of Energy recognizes the seriousness of those problems and is addressing them. In some cases existing management systems are being used to accomplish the new mission of environmental cleanup, and in other cases new systems have been created to help carry out that mission. Widespread criticism of those efforts to data are evidence that the management systems being used may not be appropriate for the job. In particular, it appears that some management systems aren`t producing desired results because they are not well aligned with the people and tasks for whom they are intended, and these issues are discussed in this report.
1994-04-01
International Nuclear Information System (INIS)
Autoionizing and Auger transitions in atomic manganese and samarium have been experimentally investigated by observation of the ejected electrons in the energy region 0 to 40 eV following electron impact excitation with incident beams in the energy range 15-500 eV. Seventy-four spectral features are tabulated for manganese and a number of new assignments have been made based on pseudo-relativistic Hartree-Fock calculations and quantum defect analysis. A similar study of samarium reveals only a number of broad features in the ejected-electron energy range 8-10 eV. Three features have been observed consistently in the ejected-electron spectrum of samarium and assigned by comparison with previous work. (author).
Properties of low residual stress silicon oxynitrides used as a sacrificial layer
Energy Technology Data Exchange (ETDEWEB)
Low residual stress silicon oxynitride thin films are investigated for use as a replacement for silicon dioxide (SiO{sub 2}) as sacrificial layer in surface micromachined microelectrical-mechanical systems (MEMS). It is observed that the level of residual stress in oxynitrides is a function of the nitrogen content in the film. MEMS film stacks are prepared using both SiO{sub 2} and oxynitride sacrificial layers. Wafer bow measurements indicate that wafers processed with oxynitride release layers are significantly flatter. Polycrystalline Si (poly-Si) cantilevers fabricated under the same conditions are observed to be flatter when processed with oxynitride rather than SiO{sub 2} sacrificial layers. These results are attributed to the lower post-processing residual stress of oxynitride compared to SiO{sub 2} and reduced thermal mismatch to poly-Si.
2000-01-04
Propagation of Surface Ripples on Pyrochlore Single Crystals Induced by Ion Beam Bombardment
Energy Technology Data Exchange (ETDEWEB)
The morphological evolution of ripples formed on the surface of Cd2Nb2O7 pyrochlore single crystals by focused ion beam (FIB) bombardment was investigated using in situ electron microscopy. At high ion fluences and off-normal bombardment angles, faceted surface ripples with a terrace-like structure were observed. The ripple propagation direction was oriented along the projected ion beam direction at incident angles ranging from 35 to 65 following high-dose ion bombardment. One side of the terrace was found to be perpendicular to the incident ion beam direction, while the other side was parallel to the ion beam. The terrace propagation velocity and direction were determined and interpreted on the basis of this asymmetric structure. A model based on the propagation of a shock wave that effectively self-selects a stable slope, was developed in order to explain the observed faceted ripple formation.
2009-08-01
Probing the origin of inertia behind spacetime deformation
To investigate the origin and nature of inertia, we introduce a new concept of hypothetical 2D, so-called, "master-space" (MS), subject to certain rules. The MS, embedded in the background 4D-spacetime, is an indispensable individual companion to the particle of interest, without relation to every other particle. We argue that a deformation/(distortion of local internal properties) of MS is the origin of inertia. With this perspective in sight, we construct the alternative relativistic theory of inertia (RTI), which allows to compute the relativistic inertial force acting on an arbitrary point-like observer due to its "absolute acceleration". We go beyond the hypothesis of locality with an emphasis on distortion of MS, which allows to improve essentially the standard metric and other relevant geometrical structures related to the noninertial reference frame of an arbitrary accelerated observer. We compute the inertial force ...
2011-01-01
POP bioaccumulation in macroinvertebrates of alpine freshwater systems
International Nuclear Information System (INIS)
This study serves to investigate the uptake of POPs in the different trophic levels (scrapers, collectors, predators, shredders) of macroinvertebrate communities sampled from a glacial and a non-glacial stream in the Italian Alps. The presented results show that the contaminant concentrations in glacial communities are generally higher compared to those from non-glacial catchments, highlighting the importance of glaciers as temporary sinks of atmospherically transported pollutants. Moreover, the data also suggests that in mountain systems snow plays an important role in influencing macroinvertebrate contamination. The main chemical uptake process to the macroinvertebrates is considered to be bioconcentration from water, as similar contaminant profiles were observed between the different trophic levels. The role of biomagnification/bioaccumulation is thought to be absent or negligible. The enrichment of chemicals observed in ...
2009-12-01
Microstructure characterization and tensile properties of b phase containing TiAl pancake
British Library Electronic Table of Contents (United Kingdom)
The microstructure and tensile properties of Ti-44Al-6V-3Nb-0.3Y (at.%) alloy after canned forging were investigated. SEM results showed that the TiAl pancake exhibits inhomogeneous microstructure, which can be ascribed to the temperature drop and friction between billet and outer pack during forging, as well as the intrinsic anisotropy of lamellar colony. By means of TEM observation and EBSD analysis, the microstructure in the dominant area of the pancake was further characterized. This deformation area consists of 87.7% content of g grains plus some refined lamellar colonies and the rest of B2 grains. The grain size ranges between 1mm and 8.5mm. High-angle boundaries dominate the deformation microstructure, several substructures and twins are observed as well. Additionally, current forge...
2011-01-01
Measurement of the dark matter velocity anisotropy profile in galaxy clusters
Dark matter particles form halos that contribute the major part of the mass of galaxy clusters. The formation of these cosmological structures have been investigated both observationally and in numerical simulations, which have confirmed the existence of a universal mass profile. However, the dynamic behaviour of dark matter in halos is not as well understood. We have used observations of 16 equilibrated galaxy clusters to show that the random velocities of dark matter particles are larger on average along the radial direction than along the tangential, and that the magnitude of this velocity anisotropy is radially varying. Our measurement implies that the collective behaviour of dark matter particles is fundamentally different from that of normal particles and the radial variation of the anisotropy velocity agrees with the predictions of numerical simulation.
2008-01-01
Magnetic layer formation on plasma nitrided CoCrMo alloy
British Library Electronic Table of Contents (United Kingdom)
In this study structural and magnetic character of the expanded austenite phase (gN) layer formed on a medical grade CoCrMo alloy by a low-pressure Radio-Frequency plasma nitriding process was investigated. The formation of the expanded austenite phase is facilitated at a substrate temperature near 400^oC for 1, 2, 4, 6 and 20h under a gas mixture of 60% N2-40% H2. The magnetic state of the gN layers was determined by a surface sensitive technique, magneto-optic Kerr effect (MOKE), and with a scanning probe microscope in magnetic force mode (MFM). Strong evidence for the ferromagnetic nature of the gN-(Co,Cr,Mo) phase is provided by the observation of stripe domain structures and the hysteresis loops. The ferromagnetic state for the gN phase observed here is mainly linked to large lattice ...
2011-01-01
MAGIC Telescope observations of high energy gamma-rays from globular cluster M13
Energy Technology Data Exchange (ETDEWEB)
Globular clusters are quite compact (size {proportional_to}10 pc) objects distributed spherically around the galaxy. They contain about 10{sup 5}-10{sup 6} mostly old stars. The number of millisecond pulsars in typical globular cluster is expected to be large (of the order of 100). We investigate the possible mechanism of production of high energy gamma-rays in those objects. Part of the wind energy of pulsars (energy conversion factor) is converted into relativistic leptons. Those leptons can upscatter in inverse Compton process low energy starlight and CMB photons and produce gamma-rays. MAGIC is an Imaging Atmospheric Cerenkov Telescopes located at Canary island of La Palma. We present results and discussion of the MAGIC observations of globular cluster M13.
2008-07-01
Isomeric states and spin polarization in A approx. 90 nuclei
Energy Technology Data Exchange (ETDEWEB)
The observed inhibition of M4 transitions in A approx. 90 nuclei has represented a long standing theoretical problem. In particular by calculating first- and second-order configuration mixing contributions to the inhibited M4 lifetimes of /sup 89/Y and /sup 87/Sr, it is found that the first-order perturbative treatment of the residual interaction usually used in shell-model calculations is unjustified in this case. Using random-phase approximation techniques, the renormalization effects of collective (''giant'') M4 resonances in /sup 88/Sr on the low energy M4 transitions in /sup 89/Y and /sup 87/Sr are investigated. It is concluded that the observed retardation of M4 lifetimes in these nuclei is consistent with the manifestation of nuclear spin polarization.
1980-04-01
Is hyperhomocysteinemia an Alzheimer's disease (AD) risk factor, an AD marker, or neither?
British Library Electronic Table of Contents (United Kingdom)
Alzheimer's disease (AD) is the most common form of neurodegenerative disease. The vast majority cases of AD are sporadic, without clear cause, and a combination of environmental and genetic factors has been implicated. The hypothesis that homocysteine (Hcy) is a risk factor for AD was initially prompted by the observation that patients with histologically confirmed AD had higher plasma levels of Hcy, termed hyperhomocysteinemia (HHcy), than age-matched controls. Most evidence accumulated so far implicates HHcy as a risk factor for AD onset, but there are also conflicting results. In this review we summarize reports on the relationship between HHcy and AD from epidemiological investigations, including observational studies and randomized controlled clinical trials. We also examine recent i...
2011-01-01
International Nuclear Information System (INIS)
Nano indentation analysis and transmission electron microscopy observation were performed to investigate a microstructural evolution and its influence on the hardening behavior in Fe-Cr alloys after an irradiation with 8 MeV Fe4+ ions at room temperature. Nano indentation analysis shows that an irradiation induced hardening is generated more considerably in the Fe-15Cr alloy than in the Fe-5Cr alloy by the ion irradiation. TEM observation reveals a significant population of the a0 dislocation loops in the Fe-15Cr alloy and an agglomeration of the 1/2a0 dislocation loops in the Fe-5Cr alloy. The results indicate that the a0 dislocation loops will act as stronger obstacles to a dislocation motion than 1/2a0 dislocation loops.
2008-11-01
Investigations of microstructure of thin TbFeCo films by high-resolution electron microscopy
International Nuclear Information System (INIS)
High-resolution electron microscope observations confirm the presence of small crystallites in thin TbFeCo films protected by Si_3N_4 overcoats. Selected area electron diffraction patterns in top-view projection indicate that the crystals have a face-centered-cubic structure. Microscope analysis reveals grain growth following annealing of these protected thin films at 200 degree C in vacuum, and Kerr measurements yield large reductions in coercivity relative to the room-temperature value. The typical grain size visible in top-view observations increases from about 3 nm in the as-deposited samples to about 30 nm after annealing at 200 degree C for 36 h while the static coercivity, H_c, drops by about 40%. The fcc structure of the crystals is retained after annealing.
Energy Technology Data Exchange (ETDEWEB)
In order to promote environmental damage monitoring and environmental impacts assessment caused by mining in China, the most significant project that uses advanced Earth Observation technology to assess environmental impacts caused by mining, namely MINEO (assessment and monitoring the environmental impact of mining activities in Europe using advanced Earth Observation technology) was introduced and its enlightenment to China were investigated. It was proposed that an integrated technical framework of monitoring environmental impacts caused by mining be designed, quantitative inversion of biological and environmental parameters from RS data be emphasised, hyperspectral Remote Sensing be applied, RS and GIS be integrated with professional models, multi-object applications of RS be implemented, and related standards and specification be drawn up based on typical case study sites. 23 refs., 1 fig.
2008-01-15
Influence of annealing on the microstructure of commercial Mg alloy AZ31 after mechanical forming
International Nuclear Information System (INIS)
The microstructure of commercial rolled magnesium alloy AZ31B (nominal composition Mg-3Al-0.9Zn-0.15Mn in wt.%) was investigated with the help of light microscopy, electron backscatter diffraction (EBSD) and X-ray diffraction technique after annealing in the temperature range from room temperature (RT) to 400 deg. C. Tensile tests at RT were performed to show the influence of the microstructure on mechanical properties. Static recrystallization (SRX) was observed during annealing of as-received alloy at and above 150 deg. C. Twins play an important role during SRX and serve as nucleation sites and preferred paths for growth of grains. The strong basal texture caused by rolling was weakened by SRX. Significant differences in the stress strain curves were observed for as-received and annealed specimens.
2006-09-25
First observation of psi(2S)-->K_S K_L
The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\\pm 0.47 \\pm 0.48)\\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\\pi^+\\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.
2003-01-01
Extracellular matrix of plant callus tissue visualized by ESEM and SEM
British Library Electronic Table of Contents (United Kingdom)
Actinidia deliciosa endosperm-derived callus culture is stable over a long period of culture. This system was used to investigate the ultrastructure of extracellular matrix occurring in morphogenic tissue. Specimens were prepared by different biological techniques (chemical fixation, liquid nitrogen fixation, glycerol substitution, critical-point drying, lyophilization) and observed by scanning electron microscopy (SEM). Fresh and wet samples were analyzed with the use of environmental scanning electron microscopy (ESEM). Extracellular matrix was observed on the surface of cell clusters as a membranous layer or reticulated network, shrunken or wrinkled, depending on the procedure. Generally, shrunken membranous layers with a globular appearance and fibrils were noted after critical-point d...
2010-01-01
Embryo-damage induced nucleation of microcracks in an aluminum alloy under impact loading
Energy Technology Data Exchange (ETDEWEB)
The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced ...
1995-06-01
Effect of recoil implantation of oxygen on boron enhanced diffusion in silicon
International Nuclear Information System (INIS)
In device fabrication, dopants are frequently implanted into silicon through silicon dioxide masks. A consequence of this technique is the co-implantation of recoiled oxygen into the substrate. This study investigates the effect of recoiled oxygen on the widely observed transient enhanced boron diffusion. Comparison of the spreading resistance profiles of annealed through-oxide and directly implanted samples reveals that transient enhanced diffusion of boron can be suppressed by the former process. Continued annealing of the through-oxide implanted silicon recovers the enhanced diffusion of boron. This behavior is believed to be due to precipitation of recoiled oxygen. The mechanisms leading to the above observations are discussed and transmission electron microscopy support presented. 11 refs., 5 figs.
1989-04-25
Drift- or Fluctuation-Induced Ordering and Self-Organization in Driven Many-Particle Systems
According to empirical observations, some pattern formation phenomena in driven many-particle systems are more pronounced in the presence of a certain noise level. We investigate this phenomenon of fluctuation-driven ordering with a cellular automaton model of interactive motion in space and find an optimal noise strength, while order breaks down at high(er) fluctuation levels. Additionally, we discuss the phenomenon of noise- and drift-induced self-organization in systems that would show disorder in the absence of fluctuations. In the future, related studies may have applications to the control of many-particle systems such as the efficient separation of particles. The rather general formulation of our model in the spirit of game theory may allow to shed some light on several different kinds of noise-induced ordering phenomena observed in physical, chemical, biological, and socio-economic systems (e.g., attractive and ...
2002-01-01
Energy Technology Data Exchange (ETDEWEB)
Bioremediation technology is being evaluated for use on the Kwajalein Atoll, which is located in the Republic of the Marshall Islands. The study was undertaken by the Oak Ridge National Laboratory (ORNL) on behalf of the US Army Kwajalein Atoll (USAKA). During February of 1991, a team from ORNL and The University of Tennessee (UT) visited the USAKA. In addition to making on-site observations regarding microbial abundance and distribution of petroleum contaminants, they brought back to Oak Ridge various soil and water samples for detailed analyses. This report documents the biological studies of these samples and presents observations made during the period from February to April of 1991 by investigators at ORNL, UT, and the Oak Ridge Associated Universities.
1992-05-01
Asymptotic Safety, Asymptotic Darkness, and the hoop conjecture in the extreme UV
Assuming the hoop conjecture in classical general relativity and quantum mechanics, any observer who attempts to perform an experiment in an arbitrarily small region will be stymied by the formation of a black hole within the spatial domain of the experiment. This behavior is often invoked in arguments for a fundamental minimum length. Extending a proof of the hoop conjecture for spherical symmetry to include higher curvature terms we investigate this minimum length argument when the gravitational couplings run with energy in the manner predicted by asymptotically safe gravity. We show that argument for the mandatory formation of a black hole within the domain of an experiment fails. Neither is there a proof that a black hole doesn't form. Instead, whether or not an observer can perform measurements in arbitrarily small regions depends on the specific numerical values of the couplings near the UV fixed point. We further ...
2010-01-01
A micro-alloyed ferritic steel strengthened by nanoscale precipitates
British Library Electronic Table of Contents (United Kingdom)
A ferritic steel with finely dispersed precipitates was investigated to reveal the fundamental strengthening mechanisms. The steel has a yield strength of 760MPa, approximately three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels, and its ultimate tensile strength reaches 850MPa with an elongation-to-failure value of 18%. Using energy dispersive X-ray spectroscopy (EDXS) and transmission electron microscope (TEM), fine carbides TiC with an average diameter of 10nm were observed in the ferrite matrix of the 0.08%Ti steel, and some cubic M23C6 precipitates were also observed at the grain boundaries and the interior of the grains. The finely dispersed TiC precipitates in the matrix provide matrix strengthening. The estimated magnitude of precipitation ...
2011-01-01
The static indentation behavior of composite sandwich panels with thin quasi-isotropic skins
The quasi-static normal indentation of sandwich panels with quasi-isotropic laminated composite skins and honeycomb or foam cores, by spherical indentors, has been investigated using experiments and finite element analysis. The experimental program emphasized the effects of indentor size on the resulting load indentation responses, failure mechanisms in the skin and the core, and the measurement of contact areas between indentor and the target. The sandwich panels were indented up to the initiation of skin fracture and the resulting contact data was used to characterize contact power laws. A non-linear finite element model was developed based on the experimental observations to systematically explore the indentation behavior of diverse sandwich configurations and to investigate the contact pressure distributions. The finite element model was used as an experimental tool in the development of a simple non-dimensional ...
2001-01-01
Waste management at Los Alamos: Protecting our environment
Energy Technology Data Exchange (ETDEWEB)
This report consists of a broad overview of activities at Los Alamos National Laboratory (LANL). The following topics are discussed: The growth of the waste management group; what we do today; the mission of the waste management group; the liquid waste treatment section; the radioactive liquid waste project office; the chemical waste section; the radioactive waste section; and the technical support section.
1993-11-01
Secretary Cheney's 1990 Annual Report to the President and the Congress established the requirement for the Unified Commanders in Chief to be prepared for Third World conflict involving roles and missions requiring, 'mobile, highly ready, well equipped fo...
1990-01-01
Third SEI Technical Interchange: Proceedings. [Space Exploration Initiative
Given here are the proceedings of the 3rd Space Exploration Initiative (SEI) Technical Interchange. Topics covered include the First Lunar Outpost (FLO), the Lunar Resource Mapper, lunar rovers, lunar habitat concepts, lunar shelter construction analysis, thermoelectric nuclear power systems for SEI, cryogenic storage, a space network for lunar communications, the moon as a solar power satellite, and off-the-shelf avionics for future SEI missions.
1992-01-01
National Aeronautics and Space Administration (NASA)
The second in a series of flights to assemble the Japanese segment of the International Space Station saw the mammoth Kibo module delivered to the complex complements of Discovery and its crew on the STS-124 mission. Kibo, the Japanese word for u201chopeu201d would house dozens of experiments and serve as a platform for external payloads brought to the complex on subsequent Shuttle flights and the Japanese u201cKounotoriu201d H-2 Transfer Vehicle cargo ship.
2011-07-10
Planning and operational considerations for units utilizing military workingn> dogs.
Military working dogs are rapidly becoming integral to military operations. While they bring many valuable capabilities to the battlefield, it is important that Special Operations leaders consider canine team capabilities and requirements when planning missions. Careful logistical and operational planning can optimize the health, performance, and readiness of the working dog while protecting the safety and well-being of the team members working with them. We also offer recommendations for medical treatment of dog bites. PMID:19813342
2009-01-01
Lee Oral History, January 16, 2008 - Johnson Space Center
Jan 16, 2008 ... home town, and awards, as well as the ground personnel. .... I was also awarded six air medals, which were given based on the number of missions ..... We took these projects from birth to grave. .... Japanese sonar on their submarine. About that time another airplane dropped a bomb ...
Laser weapons. II - Strategic laser weapons
Potential strategic missions for laser weapons, particularly those involving space-based lasers, are discussed. The functions of space-based lasers and the history of their conceptual development are summarized, and the problems of implementing such systems, including the building of a suitable laser and power source, and resolving the problem of optics, are discussed. Ongoing development programs are described, and the contrasting views of the necessity and usefulness of strategic laser systems are set forth.
1982-07-01
Energy Technology Data Exchange (ETDEWEB)
U.S. Department of Energy (DOE) Policy 450.4, Safety Management System Policy commits to institutionalizing an Integrated Safety Management System (ISMS) throughout the DOE complex as a means of accomplishing its missions safely. DOE Acquisition Regulation 970.5204-2 requires that contractors manage and perform work in accordance with a documented safety management system.
2000-01-10
International Nuclear Information System (INIS)
The mission of the Waste Management Institute is two-fold: (1) to enhance awareness and understanding of waste problems and their management in our society and, (2) to provide leadership in research, instruction and outreach to improve the quality of life on a global scale and protect the environment.
1993-10-11
Information systems definition architecture
Energy Technology Data Exchange (ETDEWEB)
The Tank Waste Remediation System (TWRS) Information Systems Definition architecture evaluated information Management (IM) processes in several key organizations. The intent of the study is to identify improvements in TWRS IM processes that will enable better support to the TWRS mission, and accommodate changes in TWRS business environment. The ultimate goals of the study are to reduce IM costs, Manage the configuration of TWRS IM elements, and improve IM-related process performance.
1996-06-20
Hybrid electric vehicles TOPTEC
Energy Technology Data Exchange (ETDEWEB)
This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.
1994-06-21
Fission fragment rockets: A new frontier
Energy Technology Data Exchange (ETDEWEB)
A new reactor concept is described which would enable fission fragments to be continuously extracted from the reactor. Such a reactor has the potential of enabling extremely energetic and ambitious deep space missions. In this talk the basic physics issues involved in the operation of this type of reactor are outlined, and some possible applications to space exploration are described. 3 refs., 2 figs., 3 tabs.
1989-04-01
Environmental interactions working group report
Energy Technology Data Exchange (ETDEWEB)
Interactions between spacecraft systems and the space charged particle environment are reviewed and recommendations are presented for both near-term and far-term research considerations. Transient environment models, large space structures, solar and nuclear power systems/environment interactions, single event upsets, material degradation, and planetary missions are addressed.
1984-04-01
Activity report 2001; Rapport annuel d'activite 2001
Energy Technology Data Exchange (ETDEWEB)
The DED, Department of the Wastes Studies, part of the Direction of the Nuclear Energy of the CEA, regroups knowledge in the domain of the chemistry, the biochemistry, the process measures and simulation engineering applied to the radioactive wastes management. This annual report presents for the year 2001 the missions, the organization, the scientific collaborations, the research programs and the publications of the Department. (A.L.B.)
2001-07-01
Mission, threat and capabilities adaptations in the twenty-first century continue to change the tasks assigned to U.S. Army Infantry units. Traditional infantry tactical training does not prepare U.S. infantry forces for many of the tasks required in cont...
2003-01-01
Hydrogen synthesis via combustion of fuel-rich natural gas/air mixtures at elevated pressure
Energy Technology Data Exchange (ETDEWEB)
Combustion of extremely fuel-rich ({phi}=4) methane/air mixtures at elevated pressures is investigated as a potential means to generate molecular hydrogen by non-catalytic partial oxidation. This system is investigated both computationally and experimentally. The computations use a perfectly-stirred reactor model and an explicit methane cool-flame mechanism to investigate the effects of reactor parameters on reaction time and product composition. Under adiabatic conditions, such mixtures are predicted to autoignite at low temperatures {approx}700 K for pressures exceeding 8.5 atm. Above 15 atm, conversion to products is complete in roughly 1 s. The dependence of reaction time and hydrogen yield is investigated as a function of inlet temperature, system pressure, and flame equivalence ratio. Actual product yields are measured in a tube reactor facility, and many of the predictions of the model, including ...
2005-07-01
Failure analysis of CO_2 anti-freezing heater at Daya Bay Nuclear Power Station
International Nuclear Information System (INIS)
In this paper, an investigation was performed on a failure pressure vessel, which was as an anti-freezing heater for General Gas Storage and Distribution (SGZ) system. Evident and serious deformation was observed on the body of the vessel. A metallurgical investigation was conducted to establish the mechanism and cause of deformation of the anti-freezing heater at Daya Bay PWR station in China. The investigation, which was performed on specimens cut from the most serious area deformed of the vessel, included macroscopic examination and microscopy examination. The results of the examinations showed that some lamellar pearlite in the microstructure were already spheroidized. It was confirmed that the vessel was operated at high temperature. Stress analysis for the vessel was conducted. And it was confirmed that, in ideal conditions, the vessel would be deformed at around 420 C. The overall results of the ...
2002-09-23
Transformation kinetics and microstructures of Ti17 titanium alloy during continuous cooling
International Nuclear Information System (INIS)
We have investigated the microstructure evolutions in the Ti17 near #beta# titanium alloy during heat treatments. The phase transformation has first been studied experimentally by combining X-ray diffraction analysis, electrical resistivity and microscopy observations. From a series of isothermal treatments, a IT diagram has been determined, which takes into account the different morphologies. Then, a Johnson-Mehl-Avrami-Kolmogorov (JMAK) model has been successfully used to describe the phase transformation kinetics during either isothermal or cooling treatments. Finally, the coupling of the JMAK model to the finite element software ZeBuLoN allowed us to investigate the evolution of the spatial distribution of the different morphologies during the cooling of an aircraft engine shaft disk after forging.
2007-03-15
British Library Electronic Table of Contents (United Kingdom)
Nylon copolymer (PA6, 66) and ethylene propylene diene (EPDM) blends with and without compatibilizer were prepared by melt mixing using Brabender Plasticorder. The thermal stability of nylon copolymer (PA6, 66)/ethylene propylene diene rubber (EPDM) blends was studied using thermogravimetric analysis (TGA). The morphology of the blends was investigated using scanning electron microscopy (SEM). In this work, the effects of blend ratio and compatibilisation on thermal stability and crystallinity were investigated. The incorporation of EPDM rubber was found to improve the thermal stability of nylon copolymer. The kinetic parameters of the degradation process were also studied. A good correlation was observed between the thermal properties and phase morphology of the blends. By applying Coats ...
2008-01-01
The relationship between income and environment in Turkey: Is there an environmental Kuznets curve?
British Library Electronic Table of Contents (United Kingdom)
In this study, we investigate the relationship between income and environmental quality for Turkey at two levels. First, the relationship between the CO2 emissions and per capita income is examined by the help of a time series model using cointegration techniques. In the second stage, the relationship between income and air pollution is investigated by using PM10 and SO2 measurements in Turkish provinces. In this part of the study panel data estimation techniques are utilized. The time series model covers 1968-2003, and the panel data model covers 1992-2001 including observations from 58 provinces. A monotonically increasing relationship between CO2 and income is found in the long-run according to time series analysis. On the other hand, panel data analysis indicates an N-shape relationshi...
2009-01-01
Polarity of prismatic facets delimiting WC grains in WC-Co alloys
British Library Electronic Table of Contents (United Kingdom)
This study reports a determination of the polarity of WC facets in WC-Co alloys sintered at the liquid state. In these alloys, WC grains are delimited by basal facets and two sets of {101 0} prismatic facets, one set of facets being much more developed than the other. A variation of the shape is observed as a function of the composition of the alloy. High resolution transmission electron microscopy is used to investigate the polarity of the prismatic facets owing to the typical triangular patterns appearing on the images. The effect of the composition is investigated using two alloys with different carbon potentials and one containing VC and Cr3C2 as grain growth inhibitors. The interpretation of the images shows that in all cases, the same set of prismatic planes is favoured.
2010-01-01
Mammary carcinogenesis in the rat after low-dose irradiation
International Nuclear Information System (INIS)
Carcinogenesis is now generally recognized to be an important detrimental effect in man after low dose irradiation. The carcinogenic action of ionizing radiation is clearly demonstrated after exposure to relatively high doses (in excess of 0.5 Gy) but for lower dose levels reliable direct observations are not available. With the introduction of special protocols for the performance of large scale screening programs by mammography the average absorbed dose in glandular tissue in the average breast can be restricted to a value of 3 mGy per mammogram. The risk for tumor induction after exposure to these low doses can never be established from human epidemiology. In order to investigate the risk of repeated exposure to small dose of ionizing radiation the induction of mammary tumors has been investigated in rats of the WAG/Rij strain after single and fractionated irradiations with gamma-rays. (author). 8 refs., 3 figs.
1992-07-12
Laser surface modification for aqueous corrosion resistance
International Nuclear Information System (INIS)
Laser surface modification can lead to formation of a novel microstructure on the surface of a material resulting in improved surface properties. During the past one and half decades, a number of investigations have been reported on laser surface modification techniques for improving the corrosion resistance of various materials. This paper reviews various work reported on utilising laser modification techniques for enhancing the aqueous corrosion resistance of materials. The laser surface modification work carried out on materials like stainless steels, C-steels, low alloy steels and non-ferrous materials such as Zr, Zn, Al, Ni, Mg and their alloys has been covered in the review. General features observed in improving the corrosion resistance after laser processing have been discussed and scope for future investigations in this field has been highlighted. (author). 97 refs., 15 figs., 5 tabs.
Energy Technology Data Exchange (ETDEWEB)
In globulitic gray iron (3.6 wt.% C, 2.4 wt.% Si and 0.45 wt.% Mn) the decomposition of austenite into bainite is investigated in real time using a new method based on neutron scattering. During the phase transformation transmission spectra of thermal neutrons are continuously recorded containing specific Bragg edges. Thus, the transformation is followed in-situ time resolved by evaluating the relative (micro)structural fractions of the transforming phases from the heights of the corresponding Bragg edges. The progression of the transformation is described and the results are discussed. The observed late time deviations from the Avrami law are explained by residual stresses of the second kind (homogeneous microstresses), which occur during the transformation because of the different specific volumes of the phases. ((orig.))
1994-11-30
International Nuclear Information System (INIS)
In globulitic gray iron (3.6 wt.% C, 2.4 wt.% Si and 0.45 wt.% Mn) the decomposition of austenite into bainite is investigated in real time using a new method based on neutron scattering. During the phase transformation transmission spectra of thermal neutrons are continuously recorded containing specific Bragg edges. Thus, the transformation is followed in-situ time resolved by evaluating the relative (micro)structural fractions of the transforming phases from the heights of the corresponding Bragg edges. The progression of the transformation is described and the results are discussed. The observed late time deviations from the Avrami law are explained by residual stresses of the second kind (homogeneous microstresses), which occur during the transformation because of the different specific volumes of the phases. ((orig.)).
1994-11-01
International Nuclear Information System (INIS)
The Moessbauer emission spectrum of "2"4"1Am metal was investigated for influences of radiation self damage. Samples were kept continuously for 230 h at 4.2 K and spectra were taken each 10 to 20 h. No change in f-factor was observed, while the linewidth increased monotonically and reached saturation after approximately 180 h. The original width could be reproduced by a brief warming to room temperature. The increase in width reflects the change in quadrupole interaction due to the creation of lattice defects. The constancy of the f-factor indicates that the basic crystalline structure is retained.
Intertemporal risk-return trade-off in foreign exchange rates
British Library Electronic Table of Contents (United Kingdom)
We investigate the intertemporal risk-return trade-off of foreign exchange (FX) rates for ten currencies quoted against the USD. For each currency, we use three risk measures simultaneously that pertain to that currency; its realized volatility, its realized skewness, and its value-at-risk. We apply monthly FX excess returns and risk measures calculated from daily observations. We find that there is a significant contemporaneous risk-return trade-off for the currencies under investigation. There is no evidence of noncontemporaneous risk-return trade-off. We pay special attention to the risk-return trade-off during the recent financial crisis.
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Dynamic testing of a phosphoric acid-based high temperature PEM fuel cell shows a peculiar phenomenon. A certain current loss is observed after temperature cycling at constant voltage. This loss is incidentally recovered by applying a cell voltage spike to open circuit voltage. Experimental investigations into temperature, cell voltage, and ageing effects show that this phenomenon might occur due to the orientation of the adsorbed phosphate species on the platinum catalyst surface. Along with some supporting literature and experimental results, a hypothesis is presented in order to explain this occurrence. Phosphoric acid adsorption hysteresis on platinum catalyst due to temperature cycling could cause the temporary cell current loss. Electrode potential-dependent molecule symmetr...
2011-01-01
Emissions and efficiency from production cooktop burners firing natural gas
Energy Technology Data Exchange (ETDEWEB)
Investigations were conducted on the range of emission rates of NO, NO[sub 2], CO and hydrocarbons, and the thermal efficiencies produced by each burner on three production cookers, supplied by different Australian manufacturers. It was found that the emissions and efficiencies were markedly affected by (1) the thermal input, both with and without a load on the burner, and (2) the load-height to flame-length ratio, with a load on the burner. The effect of hydrocarbon leakage into the secondary/dilution air was investigated, to explain the observed correlation of hydrocarbon emission rate with dilution air flow. The hydrocarbons were found to arise from two sources: -leakage from the stabilisation ports at the base of the burner, which was found to be significant at the higher thermal input; -incomplete combustion of the fuel in the premix, which was the dominant source of hydrocarbons emissions at the lower thermal input. ...
1994-12-01
Contribution of climatic and anthropogenic effects to the hydric deficit of peatlands
British Library Electronic Table of Contents (United Kingdom)
Abstract The present study makes use of a detailed water balance to investigate the hydrological status of a peatland with a basal clay-rich layer overlying an aquifer exploited for drinking water. The aim is to determine the influence of climate and groundwater extraction on the water balance and water levels in the peatland. During the two-year period of monitoring, the hydrological functioning of the wetland showed a hydric deficit, associated with a permanent unsaturated layer and a deep water table. At the same time, a stream was observed serving as a recharge inflow instead of draining the peatland, as usually described in natural systems. Such conditions are not favourable for peat accumulation. Field investigations show that the clay layer has a high hydraulic conductivity (from 11...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Tri layer hybrid composites of oil palm empty fruit bunches (EFB) and jute fibres was prepared by keeping oil palm EFB as skin material and jute as the core material and vice versa. The chemical resistance, void content and tensile properties of oil palm EFB/Jute composites was investigated with reference to the relative weight of oil palm EFB/Jute, i.e. 4:1, the fibre loading was optimized and different layering pattern were investigated. It is found from the chemical resistance test that all the composites are resistant to various chemicals. It was observed that marked reduction in void content of hybrid composites in different layering pattern. From the different layering pattern, the tensile properties were slightly higher for the composite having jute as skin and oil palm EFB as core ...
2011-01-01
Bandgap properties of the indium sulfide thin-films grown by co-evaporation
British Library Electronic Table of Contents (United Kingdom)
In the present study the optical properties of co-evaporated indium sulfide thin films are investigated. Before being optically characterized, the composition as well as the crystalline properties of the film have been checked with the help of energy dispersive spectroscopy (EDX) and X-Ray diffraction (XRD) analyses. The optical absorption coefficient ? of this indium sulfide film has been deduced from reflectivity R(?) and transmission T(?) measurements. The fit of the curve representing ?(h?) suggests that the ?-In2S3 has an indirect bandgap of 2.01?eV. Density functional theory (DFT) calculations are performed on this indium sulfide compound, using TB-LMTO code. Through these band structure investigations, an indirect bandgap is predicted as observed experimentally. The top of the valen...
2009-01-01
Association of brain cancer with dental x-rays and occupation in Missouri
International Nuclear Information System (INIS)
This investigation of a brain cancer cluster in Missouri used two approaches to investigate associations with potential risk factors. In a case-control study in a rural town, we interviewed surrogates of cases and controls about potential risk factors. We found a statistically significant positive association of brain cancer with reported exposure to dental x-rays. Occupation was not associated with the cluster in the rural town. In a standardized proportional mortality study for the state of Missouri, we calculated the observed and expected proportion of brain cancers by occupation and industry in Missouri decedents. We found that motor vehicle manufacturers, beauty shop workers, managers and administrators, elementary school teachers, and hairdressers and cosmetologists had significantly elevated proportions of brain cancer. Brain tumors are inconsistently associated with occupation in the literature. Further study of ...
1991-01-01
International Nuclear Information System (INIS)
Charge carrier profiles are measured for boron implanted into silicon (E = 30 keV, dose range 5 x 10"1"5 to 2 x 10"1"6 B/cm"2) after rapid isothermal annealing using halogen lamps. Maximum temperatures between 1000 and 1300 "0C and holding times at T/sub max/ of 5 and 20 s are used for the annealing treatment. In a few additional experiments flash lamp annealing at 1350 "0C (pulse duration 20 ms) is investigated. By comparison of the experimental profiles with computer simulations using the SUPREM II program transient enhanced diffusion of boron could be detected in all investigated cases. Maximum charge carrier concentrations above the equilibrium solubility of boron are observed and are discussed. (author).
Energy Technology Data Exchange (ETDEWEB)
Installation of new Shortwave Spectrometer for permanent operation at SGP - In May 2006 the new ShortWave Spectrometer (SWS) was installed in the Optical Trailer at the Southern Great Plains Central Facility SGP on 27 April 2006. The SWS began full operation 28 April 2006 and has run continuously to the present. Over 25 GB of spectra has been collected, calibrated and archived. 3-D radiative transfer simulations - Retrieved fields of cloud optical thickness and effective radius to from the MODIS Airborne Simulator were used to reproduce 3D cloud fields that were used a input to 3D radiative transfer simulations and then compared with simultaneous Solar Spectral Flux Radiometer (SSFR) spectral irradiance measurements. The influence of both horizontal and vertical cloud structure, using accurate versus approximated optical properties in the radiative transfer model on the modeled irradiance was examined, as was the influence of using the full phase function versus using approximations of ...
2009-05-26
Energy Technology Data Exchange (ETDEWEB)
Molar excess volumes, V{sup E}, molar excess enthalpies, H{sup E}, and speeds of sound data, u, of chloroform (i) + aniline or o-toluidine (j) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes of mixing, {kappa}{sub S}{sup E} have been determined by employing speed of sound data. Topological investigations of V{sup E} data reveals that aniline, chloroform and o-toluidine are associated entities and these (i + j) mixtures contain a 1:1 molecular complex. The IR studies lend further support to the nature and extent of interaction for the proposed molecular entity in the mixtures. H{sup E} and {kappa}{sub S}{sup E} values have also been calculated by employing Moelwyn-Huggins concept [Polymer 12 (1971) 387] taking topology of the constituents of the mixtures. It has been observed that calculated H{sup E} and {kappa}{sub S}{sup E} values compare well with their corresponding experimental ...
2008-05-30
International Nuclear Information System (INIS)
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound data, u, of chloroform (i) + aniline or o-toluidine (j) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes of mixing, ?SE have been determined by employing speed of sound data. Topological investigations of VE data reveals that aniline, chloroform and o-toluidine are associated entities and these (i + j) mixtures contain a 1:1 molecular complex. The IR studies lend further support to the nature and extent of interaction for the proposed molecular entity in the mixtures. HE and ?SE values have also been calculated by employing Moelwyn-Huggins concept [Polymer 12 (1971) 387] taking topology of the constituents of the mixtures. It has been observed that calculated HE and ?SE values compare well with their corresponding experimental values. The observed VE, HE and ?SE data have also been ...
2008-05-30
We investigate the physics of the lightest CP-even MSSM Higgs boson at the Tevatron, the LHC, a linear e+e- collider, a gamma gamma collider and a mu+mu- collider. The analysis is performed in the three most prominent soft SUSY-breaking scenarios, mSUGRA, mGMSB and mAMSB. For all colliders the observability and parameter regions with suppressed production cross sections (compared to a SM Higgs boson with the same mass) are investigated. For the lepton and photon colliders the potential is analyzed of precision measurements of the branching ratios of the light CP-even Higgs boson for obtaining indirect bounds on the mass of the CP-odd Higgs boson and the high-energy parameters of the soft SUSY-breaking scenarios. In regions of the parameter space where the LHC can detect the heavy Higgs bosons, precision measurements of the properties of the light Higgs boson at the linear collider can provide valuable information for ...
2003-01-01
The entomopathogenic nematode (EPN), Steinernema feltiae, is a commonly occurring nematode in the soil in Ireland. Consequently, we have conducted investigations as to the utility of this species as a candidate organism for the detection of chromium in Irish soils. These experiments have demonstrated that S. feltiae can survive and reproduce in the presence of high concentrations of chromium VI. It was observed that concentrations as high as 1000 ppm have little effect on the ability of this organism to produce large numbers of progeny. Nematodes were not observed to reproduce above 1800 ppm. However, an increase in development times for the nematode in vivo was noted at concentrations of 400 ppm upwards. This paper also illustrates the effects upon the beta-tubulin genes within nematode populations exposed to chromium VI in vivo. DNA sequencing has shown that elevated levels of variations occur among the population ...
2008-07-18
Spatial Damping of Propagating Kink Waves Due to Resonant Absorption: Effect of Background Flow
Observations show the ubiquitous presence of propagating magnetohydrodynamic (MHD) kink waves in the solar atmosphere. Waves and flows are often observed simultaneously. Due to plasma inhomogeneity in the perpendicular direction to the magnetic field, kink waves are spatially damped by resonant absorption. The presence of flow may affect the wave spatial damping. Here, we investigate the effect of longitudinal background flow on the propagation and spatial damping of resonant kink waves in transversely nonuniform magnetic flux tubes. We combine approximate analytical theory with numerical investigation. The analytical theory uses the thin tube (TT) and thin boundary (TB) approximations to obtain expressions for the wavelength and the damping length. Numerically, we verify the previously obtained analytical expressions by means of the full solution of the resistive MHD eigenvalue problem beyond the TT ...
2011-01-01
Observational approach implementation guidance: Year-end report
Energy Technology Data Exchange (ETDEWEB)
It is generally recognized that the Remedial Investigation/Feasibility Study (RI/FS) process can be time-consuming and costly. To expedite the process, the Environmental Protection Agency, through the National Contingency Plan and Office of Solid Waste and Emergency Response (OSWER) Directives, has promoted streamlining'' the RI/FS. The concept of streamlining is directly applicable to Resource Conservation and Recovery Act (RCRA) Remedial Facility Investigation/Corrective Measure Study (RFI/CMS) as well. The US Department of Energy's (DOE's) environmental restoration process promises to be lengthy and expensive: therefore, the Office of Environmental Restoration (EM-40) believes that it is to incorporate streamlining into RI/FS and RFI/CMS efforts across the DOE complex. The Office of Program Support (EM-43) has asked Pacific Northwest Laboratory (PNL) to provide presentations and workshops on streamlining ...
1992-06-01
Environmental Research Database
ObjectivesThe overall scientific aim of this project is, through development of an appropriate numerical modelling tool, to identify and investigate the mechanisms that control the current observed rapid thinning and acceleration of Greenland outlet glaciers and to investigate their likely future behaviour in the context of climate warming. This aim is addressed through the four major specific objectives below. These objectives build on each and therefore the order of priority is driven by the order in wh [continued...]DescriptionCurrently, the Greenland ice sheet is undergoing rapid changes in the coastal regions which have been attributed to a general warming trend to the regions climate over the last decade. Several of the narrow and fast flowing outlet glaciers that drain the ice sheet into the sea are observed to have accelerated their flow and thinned. For instance, Jakobshavn Isbrae on the West ...
2008-01-31
Investigation of lubrication in natural joints by neutron reflectometry
Energy Technology Data Exchange (ETDEWEB)
Despite their high medical relevance, the principles of lubrication in natural joints are still unclear. It is generally accepted, that the presence of hyaluronic acid (HA), the main component of the synovial liquid, plays an important role for the low friction observed. Furthermore, it is assumed that surface active lipids participate in the lubrication. Using a model system of lipid bilayers deposited on a polyelectrolyte (PE) cushion and in contact with HA solution, we started to investigate the effects of pressure and shear forces, as experienced by natural joints, on the internal structure of the SiO{sub 2}/PE/lipid/HA interface and the bulk HA solution by neutron reflectometry (NR), complemented by in situ ellipsometry and quartz crystal microbalance (QCM-D) measurements. Only on positively charged polyelectrolyte surfaces, the successful build-up of the model system could be demonstrated. By NR, the existence of an irreversibly absorbed, ...
2007-07-01
Effect of dysprosium doping on the optical properties of SrS:Dy,Cl phosphor
International Nuclear Information System (INIS)
The fundamental optical properties of dysprosium (Dy) doped strontium sulfide bulk samples for various dopant concentrations from 0.1 to 1.0 at.% were investigated by X-ray diffraction (XRD), electron paramagnetic resonance spectroscopy (EPR), room temperature photoluminescence (PL), photoluminescence excitation (PLE) and diffuse reflectance spectroscopy (DRS). Investigations by electron paramagnetic resonance yielded the state of Dy in the sample as Dy3+. An additional ESR line due to F+ center was observed. The PL emission spectrum consisted of several intense lines and a number of weaker ones which were identified as transitions between energy levels of Dy3+. The optimum doping concentration for maximum intensity was found to be 0.25 at.%. Blue shift of the absorption edge energy and red shift of the PLE spectrum were observed with increasing doping concentration. The former is due to Burstein-Moss ...
2010-08-13
Energy Technology Data Exchange (ETDEWEB)
Molar excess volumes, V{sup E}, molar excess enthalpies, H{sup E}, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, {kappa}{sub S}{sup E} of (i + j) mixtures. The observed V{sup E}, H{sup E} and {kappa}{sub S}{sup E} data have been analyzed in terms of Graph theory. The analysis of V{sup E} data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that V{sup E}, H{sup E} and {kappa}{sub S}{sup E} values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
2008-09-15
International Nuclear Information System (INIS)
Molar excess volumes, VE, molar excess enthalpies, HE, and speeds of sound, u, of o-toluidine (i) + cyclohexane or n-hexane or n-heptane (j) binary mixtures have been determined over entire range of composition at 308.15 K. Speeds of sound data have been utilized to predict isentropic compressibility changes of mixing, ?SE of (i + j) mixtures. The observed VE, HE and ?SE data have been analyzed in terms of Graph theory. The analysis of VE data by Graph theory reveals that o-toluidine exists as an associated molecular entity and (i + j) mixtures contain 1:1 molecular complex. It has been observed that VE, HE and ?SE values calculated by Graph theory compare well with their corresponding experimental values. The observed data have also been analyzed in term of Flory theory.
2008-09-15
THE EVOLUTION OF CLOUD CORES AND THE FORMATION OF STARS
International Nuclear Information System (INIS)
For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences of these oscillations on the evolution of the cores and the interpretation of their observations. We find that the pulsation energy helps support the cores and that the dissipation of this energy can lead toward instability and star formation. In this picture, the core lifetimes are limited by the pulsation-decay timescales, dominated by non-linear mode-mode coupling, and on the order of #approx =# few x 10"5-10"6 yr. Notably, this is similar to what is required to explain the relatively low rate of conversion of cores into stars. For cores with large-amplitude oscillations, dust continuum observations may appear asymmetric or irregular. As a consequence, some of the cores that would be classified as super-critical may be dynamically stable when ...
2010-09-20
Energy Technology Data Exchange (ETDEWEB)
Burnup calculations with SARC system were carried out to analyse the effects of plutonium build-up on criticality of MTR type research reactor PARR-1 using several WIMSD libraries based on evaluated nuclear data files ENDFB-VI.8, JEF-2.2, JEFF-3.1 and JENDL-3.2. For equilibrium core of the reactor, it was found that a net reactivity of more than 3.5 mk is induced due to build-up of plutonium isotopes during depletion. The plutonium credit amounts to 3% of the length of equilibrium cycle. From the analysis of actinide production in the core during burnup, it was observed that in most of the cases, the amounts of actinides obtained using various cross section libraries agree fairly with each other, however, significant differences were observed for {sup 238}Pu, {sup 241}Pu, {sup 242m}Am, {sup 243}Am, {sup 242}Cm and {sup 244}Cm for some libraries. The actinide chain analysis was conducted to investigate the reasons for the ...
2006-12-15
Non-equilibrium modelling of an oxygen-plasma cutting torch
International Nuclear Information System (INIS)
A two-temperature, axi-symmetric, chemical non-equilibrium model has been developed for an oxygen-plasma cutting torch in two dimensions to obtain distributions of different plasma quantities inside the torch. Apart from mass, momentum and potential conservation equations, separate energy balance equations are considered for electrons and heavy particles. The ?-? model has been used to account for turbulence. Non-equilibrium properties required for fluid dynamic simulations are obtained from a non-equilibrium property code that includes chemical non-equilibrium. The results show distributions of temperature, velocity, pressure, potential, current density and different species densities inside the plasma torch for an arc current of 200 A. Plasma pressure inside the torch varies from several atmospheres to near-atmospheric pressure. It has been observed that the electron and the heavy particle temperatures differ less near the axis of the torch and appreciably near ...
2007-04-07
International Nuclear Information System (INIS)
This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr"3"+ doped ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red emissions were observed with a laser diode (LD ...
2004-04-15
Nanoporous structure formations on germanium surfaces by focused ion beam irradiations
International Nuclear Information System (INIS)
The formation of porous structures of nanometre size (nanoporous structures) on germanium (Ge) surfaces by focused ion beam (FIB) irradiations was investigated using various FIB conditions such as ion species, irradiation energies, total fluences, fluence rates, and incident angles. FIB-irradiated regions were observed using a scanning electron microscope and an atomic force microscope. It is found that, using a focused Ga ion beam (Ga FIB) at an energy of 100 keV, the irradiated Ge surface swelled up to ion fluence of 2 x 10"1"7 cm"-"2 with nanoporous structures and then was etched for larger fluences. The shape of swollen nanoporous structures depended on the fluence rate and the incident angle of the Ga FIB. However, such porous structures were observed neither for low-energy (15-30 keV) FIB irradiations using Si and Au ions nor for high-energy (200 keV), heavy ion (Au) irradiation. These ...
2007-11-07
Multi-wavelength observations of the young binary system Haro 6-10: The case of misaligned discs
Context. We present a multi-wavelength, high-resolution observational survey of the young binary system Haro 6-10 (GV Tau, IRAS 04263+2426), which is harbouring one of the few known infrared companions. Aims. The primary goal of this project is to determine the physical and geometrical properties of the circumstellar and circumbinary material in the Haro 6-10 system. Methods. High-resolution optical (HST/WFPC2) and near-infrared (VLT/NACO) images in different bands were analysed to investigate the large-scale structures of the material around the binary.Mid-infrared interferometry (VLTI/MIDI) and spectroscopy (TIMMI2 at the 3.6m ESO telescope) were carried out to determine the structure and optical depth of the circumstellar material around the individual components. Results. The multi-wavelength observations suggest that both components of the binary system Haro 6-10 are embedded in a common envelope. The measured ...
2011-01-01
Magnetic and structural investigation of magnetic thin films with obliquely deposited underlayers
An in-plane uniaxial magnetic anisotropy has been observed in thin Co films normally deposited onto obliquely sputtered Ta and Pt underlayers. Associated with this anisotropy is an augmented easy axis coercivity. The in-plane easy axis is, in most cases, perpendicular to the incident deposition plane. Microstructural results indicate that grains are well connected along the magnetic easy axis but are separated by long continuous voids along the hard axis, which is ascribed to a geometric shadowing effect due to the oblique incidence deposition of the underlayer. Hence, the magnetic anisotropy mimics the film growth anisotropy. It is therefore believed that the observed magnetic properties are due to magnetostatic shape anisotropy effects. In-plane coercivity and anisotropy field are shown to increase with underlayer deposition angle, underlayer thickness and magnetic layer thickness. The choice of capping layer is also ...
2002-01-01
We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z=0.413) selected from the FIRST/2MASS Red Quasar survey. For this AGN, a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and HST images revealed a very disturbed host galaxy morphology. Contrary to classical, optically-selected quasars, the X-ray properties of red (i.e. with J-Ks> 1.7 and R-Ks> 4) broad line quasars are still quite unexplored, although there is a growing consensus that, due to moderate obscuration, these objects can offer a unique view of spectral components typically swamped by the AGN light in normal, blue quasars. The XMM-Newton observation discussed here has definitely confirmed the complexity of the X-ray spectrum revealing the presence of a cold (or mildly-ionized) absorber with Nh ~10^{22} cm^-2 along the line of sight to the nucleus and a Compton reflection component accompanied ...
2010-01-01
Influence of second phase particles on fracture toughness in AZ31 magnesium alloys
Energy Technology Data Exchange (ETDEWEB)
Three kinds of thin AZ31 wrought magnesium alloys sheets were used in order to investigate the influence of the second phase particles on fracture toughness. From the theoretical model, the ratio of {lambda}{sub p}/d{sub p} would be estimated 5 {proportional_to} 6. On the other hand, from the microstructural observation, average particle spacing on each material was sample A: 13.1 {mu}m, sample B: 14.1, and sample C: 12 {mu}. In addition, average particle size on each sample was sample A: 2.1, sample B: 1.9, and sample C: 2.3 {mu}m. Therefore, the ratio of {lambda}{sub p}/d{sub p} calculated from fracture surface observation would be predicted 6 {proportional_to} 7. In comparison with the result of the prediction by theoretical analysis was in good agreement with the result of fracture toughness observation. It was found that the variation in plane-strain fracture toughness on AZ31 were affected by both ...
2004-07-01
High Spatial Resolution Optical and Radio Imagery of the Circumbinary Environment
In this review, I concentrate on describing observations of spatially resolved emission in symbiotic stars at sub-arcsecond scales. In some of the closer objects, the highest resolutions discussed here correspond to linear dimensions similar to the supposed binary separation. A total of 17 stars well accepted as symbiotics are now observed to show sub-arcsecond structure, almost twice the number at the time of the last review in 1987. Furthermore, we now have access to HST imagery to add to radio interferometry. From such observations we can derive fundamental parameters of the central systems, investigate the variation of physical parameters across the resolved nebulae and probe the physical mechanisms of mass loss and interactions between ejecta and the circumstellar medium. Suggestions for future work are made and the potential of new facilities in both the radio and optical domains is described. ...
2004-01-01
Excess of seminomas observed in Vietnam service U.S. military workingn> dogs.
During the Vietnam War, US military working dogs served with their companion dog handlers in close proximity, sharing common exposures to war-related activity, many zoonotic infectious agents, chemical pesticides, phenoxy herbicides, and extensive use of therapeutic drugs. To gain insight into the effects of the Vietnam experience, we investigated the occurrence of neoplasms in military working dogs based on standard necropsy examination by the Armed Forces Institute of Pathology. We observed that these dogs experienced significant elevated risks for testicular seminoma and, independently, testicular dysfunction. Experimental evidence shows testicular dysfunction and impaired spermatogenesis in laboratory animals exposed to phenoxy herbicides, dioxin, or tetracycline, and antibiotic used extensively in military working dogs in Vietnam. Because an unexplained significant decrease in sperm quality in Vietnam veterans has been ...
1990-06-20
International Nuclear Information System (INIS)
The purpose of this research is to investigate the micro-mechanism of deformation behavior of metallic glasses. We report the results of direct observations of short-range and medium-range structural change during tensile deformation of metallic glasses by high energy X-ray diffraction method. Cu50Zr50 and Ni30Zr70 metallic glass samples in the ribbon shape (1.5 mm width and 25 ?m) were made by using rapid quenching method. Tensile deformation added to the sample was made by using special equipment adopted for measuring the high energy X-ray diffraction. The peaks in pair distribution function g(r) for Cu50Zr50 and N30iZr70 metallic glasses move zigzag into front and into rear during tensile deformation. These results of direct observation on atomic distribution change for Cu50Zr50 and Ni30Zr70 metallic glass ribbons during tensile deformation suggest that the micro-relaxations occur.
2009-08-26
Energy Technology Data Exchange (ETDEWEB)
The performance of more than 3,000 offshore platforms in the Gulf of Mexico was observed during the passage of Hurricane Andrew in August 1992. This event provided an opportunity to test the procedures used for platform analysis and design. A global bias was inferred for overall platform capacity and loads in the Andrew Joint Industry Project (JIP) Phase 1. It was predicted that the pile foundations of several platforms should have failed, but did not. These results indicated that the biases specific to foundation failure modes may be higher than those of jacket failure modes. The biases in predictions of foundation failure modes were therefore investigated further in this study. The work included capacity analysis and calibration of predictions with the observed behavior for 3 jacket platforms and 3 caissons using Bayesian updating. Bias factors for two foundation failure modes, lateral shear and overturning, were ...
1996-12-31
Energy Technology Data Exchange (ETDEWEB)
Transient enhanced diffusion of phosphorus in silicon has been investigated for implants below and above the threshold for a complete amorphization. Rapid thermal processes (electron beam) and conventional furnaces have been used for the annealing. In the case of implants below amorphization, a strong enhanced diffusion, proportional to the amount of damage produced, has been observed. The extent of the phenomenon is practically independent of the damage depth position. In contrast to this, the formation of extended defects at the original amorphous-crystalline interface makes the diffusivity strongly dependent on depth in the case of post-amorphized samples. No enhanced diffusion effect is observed if the dopant is confined in the amorphous layer, while a remarkable increase in the diffusivity is detected for the dopant located in the crystalline region beyond the amorphous-crystalline interface. Damage distribution after ...
1989-03-01
A focused ion beam (FIB) technique was applied to cross-sectional specimen preparation to observe an interface between a plasma sprayed coating and an aluminum (Al) substrate by transmission electron microscopy (TEM). The surface of the sprayed coating film has a roughness of several tens of microns. Sputter rates for the coating film and the substrate are greatly different. The rough surface and the difference in sputter rate cause problems in making TEM specimens with smooth side walls. The top surface of the coating film was planerized by the FIB before fabricating the TEM specimen. The interfaces were investigated by TEM and energy-dispersive X-ray (EDX) analysis. The TEM observation revealed that there is a 10 nm thick amorphous layer at the interface between the coating film and substrate. The coating film consists of two kinds of sublayers with bright and dark contrast. The bright contrast sublayers were amorphous ...
2000-05-01
Alignments, additivity, and signature inversion in odd-odd "1"7"0Ta: A comprehensive high-spin study
International Nuclear Information System (INIS)
High-spin states (I < or approx. 50(#Planck constant#/2#pi#)) of the odd-odd nucleus "1"7"0Ta have been investigated with the "1"2"4Sn("5"1V,5n) reaction. The resolving power of Gammasphere has allowed for the observation of eleven rotational bands (eight of which are new) and over 430 transitions (#approx#350 of which are new) in this nucleus. Many interband transitions have been observed such that the relative spins and excitation energies of the 11 bands have been established. This is an unusual circumstance in an odd-odd study. Configurations have been assigned to most of these bands based upon features such as alignment properties, band crossings, B(M1)/B(E2) ratios, and the additivity of Routhians. A systematic study of the frequency at which normal signature ordering occurs in the #pi#h_9_/_2#nu#i_1_3_/_2 band has been performed and it is found that its trend is opposite to that observed in ...
2010-06-01
The effects of packaging materials on microbe population in irradiated traditional herbal medicines
International Nuclear Information System (INIS)
Microbial population and moisture content of traditional herbal medicines contaminated with 3 kinds of aerobic microbes, packed in 5 kinds of plastic packaging materials, followed by irradiation at minimum dose of 5 kGy and stored for 6 months were investigated. The highest reduction of microbial counts during storage was observed on samples packed in polyethylene bags. All of packaging materials used were found to be impermeable to microbes and water vapour. Radiation and packaging materials used acted synergistically to inactivate microbes durind storage. The microbial counts decreased as much as 2 to 4 log cycles during storage. (author).
The AMPTE program's contribution to studies of the solar wind-magnetosphere-ionosphere interaction
Energy Technology Data Exchange (ETDEWEB)
The Active Magnetospheric Particle Tracer Explorers (AMPTE) program provided important information on the behavior of clouds of plasma artificially injected into the solar wind and the earth's magnetosphere. Now that the releases are over, data from the satellites are being analyzed to investigate the processes by which the ambient solar wind mass, momentum, and energy are transferred to the magnetosphere. Work in progress at APL indicates that the solar wind is much more inhomogeneous than previously believed, that the solar wind constantly buffets the magnetosphere, and that ground observers may remotely sense these interactions as geomagnetic pulsations. 8 refs.
1990-12-01
Texture development of AZ31 magnesium alloy during ECAE processing
Energy Technology Data Exchange (ETDEWEB)
Mg-3%Al-1%Zn (AZ31) alloy was subjected to ECAE processing at 523 and 573 K. Microstructure observation and texture analysis were carried out using optical microscope and SEM-EBSD technique in order to investigate the process of microstructural changes including texture development during ECAE processing. Grain refinement during ECAE processing is enhanced by dynamic continuous recrystallization. The texture of the ECAE-processed AZ31 alloy specimens change with ECAE processing temperature, and the textural changes relate to deformation mechanisms that change with ECAE processing temperature. (orig.)
2003-07-01
Synthesis and scintillation properties of GdCl_3:Ce"3"+ (Gd_1_-_xCe_xCl_3_,x = 0.005-0.08)
International Nuclear Information System (INIS)
Single crystals of GdCl_3 doped with different concentrations of Ce"3"+ have been grown using the Bridgman-Stockbarger technique and their luminescence and scintillation properties were investigated. The luminescence spectrum of GdCl_3:Ce"3"+ is complex and consists of two bands with maxima at 350 nm and 370 nm. The maximal light yield in GdCl_3:Ce"3"+ was observed at #approx#1 mol% of Ce"3"+ (more than 38 000 ph/MeV).
2009-07-08
Sustaining integrated technology in undergraduate mathematics
British Library Electronic Table of Contents (United Kingdom)
The effective integration of technology into the teaching and learning of mathematics remains one of the critical challenges facing contemporary tertiary mathematics. This article reports on some significant findings of a wider study investigating the use of technology in undergraduate mathematics. It first discusses a taxonomy developed to describe and compare technology use within individual courses and departments that identifies a complex range of factors, summarized under six defining characteristics of an integrated technology mathematics curriculum (ITMC). An instrument for a simple comparison of technology use employing the elements of this taxonomy is provided. It then presents evidence gathered from an observational study of technology implementation at The University of Auckland...
2011-01-01
Superplastic behaviour in Ti-3Al-4V
International Nuclear Information System (INIS)
Superplastic deformation behavior in an alpha + beta titanium alloy Ti-3A-4V has been investigated by using the method of cross head speed cycling in the temperature range 750-910 /sup 0/C. On the basis of flow stress-strain rate-strain rate sensitivity data, the alloy was found to be superplastic in the entire temperature range studied. Optimum superplasticity was observed in the strain-rate range 3 x 10/sup -5/ sec./sup -1/ to 6 x 10/sup -5/ and at the highest temperature of 910 deg. C. (author).
Superconductivity in irradiated A-15 compounds at low fluences. I. Neutron-irradiated V_3Si
International Nuclear Information System (INIS)
The behavior of the superconducting transition temperature T/sub c/ of single-crystal and polycrystalline V_3Si was investigated as a function of low-fluence neutron irradiation. It is found that the initial degradation of T/sub c/ is sample-dependent, some specimens showing no degradation in T/sub c/ up to a fluence of 2 x 10"1"8 n/cm"2. This and many other earlier observations on low-fluence behavior are explained in terms of a recently proposed model of radiation damage in A-15 compounds.
Study of d+#ALPHA# system in kinematically complete experiment at 27,2 MeV #alpha#-particle energy
International Nuclear Information System (INIS)
The "2H(#alpha#,p#alpha#)n reaction was investigated in a kinematically complete experiment with a #alpha#-beam at energy 27.2 MeV.The "5He excited state was observed and its parameters were determinate.Coincidence spectra were fitted by contribution of sequential decay through the "5He ground and excited states.The best agreement with the data was obtained assuming the following "5He excited state parameters: E_a_n=2.8 MeV #GAMMA#=2.5 MeV.
International Nuclear Information System (INIS)
Atoms in very high Rydberg states, 100 approx-lt n approx-lt 1100, are used to investigate electron-molecule interactions at electron energies extending down to a few microelectronvolts. At such energies the cross section for electron capture by CCl_4 is observed to vary inversely with electron velocity, indicative of an s-wave process. Studies with the polar target CH_3Cl suggest that dipole-supported states may be important in inelastic electron-polar molecule scattering at very low electron energies.
International Nuclear Information System (INIS)
A study of stress corrosion cracking susceptibility of Zircaloy-4 in chloride-containing aqueous methanolic media is presented. The influence of water content is investigated in the 5-100 vol. % water range. The dependence of stress corrosion cracking on potential is evidenced. A close correlation is established with pitting susceptibility determined by a statistical analysis of induction times. A correlation with the repassivation potential is observed in the water-rich solutions. In the low water content solutions, two repassivation curves are determined according to the experimental technique. Pit morphology and fractography show a transition from aqueous to organic media. (author).
Strain softening and hardening effects in Ti-6Al-4V during high temperature deformation
International Nuclear Information System (INIS)
Effect of strain and temperature on high temperature deformation properties of an alpha + beta titanium alloy Ti-6Al-4V has been investigated in the temperature range 800 to 910 deg. C by using the method of cross head speed cycling. On the basis of flow stress strain rate-strain rate sensitivity data and microstructural studies of the undeformed and deformed regions of tensile test pieces, both strain introduced hardening and softening effects were observed during the course of deformation which could be associated with grain coarsening and refining respectively. (author)
Strain induced hardening in Ti-3Al-4V at 910 deg. C
International Nuclear Information System (INIS)
High temperature deformation behavior of an alpha + beta titanium alloy Ti-3Al-4V has been investigated at 910 deg. C. by using the method of cross head speed cycling. On the basis of flow stress, strain rate and strain rate sensitivity data, the alloy was found to exhibit strain hardening at this temperature which resulted in degradation in superplastic properties of the alloy. A high beta-phase volume fraction and grain-growth in both alpha and beta phases were considered responsible for the observed hardening effect. (author)
Species dependence of the emittances of sputter-generated negative ion beams
Energy Technology Data Exchange (ETDEWEB)
We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum analysed /sup 28/Si/sup -/, /sup 58/Ni/sup -/ and /sup 197/Au/sup -/ ion beams generated by caesium ion sputtering. The high-resolution emittance measurement techniques employed in this work have enabled us to estimate the energy spreads of these ion beams; differences in the widths of the energy distributions are the origin of the observed differences in emittances of the ion beams investigated. (author).
1989-04-14
Simulation of DNA electrophoresis through microstructures
British Library Electronic Table of Contents (United Kingdom)
The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E 25 V/cm for the mobility of l-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an expl...
2007-01-01
Resistance of radiation-induced tropical wood-polymer composites to fungal degradation
Energy Technology Data Exchange (ETDEWEB)
The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.
1987-01-01
The results of a study conducted by Working Group 10 of the AGARD Fluid Dynamics Panel to investigate the limits of boundary layer methods, both the integral and field type formulations, for calculating three-dimensional turbulent separated flow are presented. Test cases used to assess the boundary layer calculations included the DFLVR prolate spheroid at angle of attack and the NASA-Ames Wing C. Comparisons between boundary layer calculations and experimental data are presented for these test cases along with observations, conclusions, and recommendations.
1990-05-01
International Nuclear Information System (INIS)
Lithium orthosilicate (Li_4SiO_4) powder was synthesized by the solid-state reaction of lithium oxide with amorphous silica, and the effects of fabrication parameters on the structural characteristics of the product were investigated. Processing considerations such as milling media, drying technique, calcination time and temperature, pressing behavior, sintering time and temperatures, and impurity concentration were addressed. The initial powder particle size was observed to be important in achieving high sintered density, with densities as high as 98% TD achieved with a particle size of approximately 1 #mu#m. 9 refs., 6 figs.
1988-04-10
International Nuclear Information System (INIS)
Phase transformations in TiD_#approx#_0_._7_5 subjected to high-pressure treatment were investigated by simultaneous real-time measurements of neutron diffraction and small-angle neutron scattering. The neutron spectra were taken on heating the samples in temperature ranges 100 to 300 K and 300 to 870 K. A sequence of structural transitions was observed, which involves 7 different phases and intermediate states with hcp, fcc, fco or bcc metal sublattices and hydrogen atoms. 30 refs., 9 figs., 1 tab.
1992-09-01
Energy Technology Data Exchange (ETDEWEB)
Methylmethacrylate polymerisation in the presence of 4 wt% butadiene-acrylonitrile rubber was carried out at fixed dose-rate and temperature. The effect of irradiation was investigated with respect to the mechanical and dynamic-mechanical properties in the solid state. A general increase of the 'compatibilisation' on irradiation is obtained. In fact both rubber and polymethylmethacrylate glass transition temperatures, determined through dynamic-mechanical analysis, reveal the presence of strong interactions between the components. Furthermore an improvement of the mechanical tensile properties of the blends is observed when irradiation is continued after polymerisation, at least until a certain absorbed dose.
2001-12-01
International Nuclear Information System (INIS)
Periosteal Ewing's sarcoma is an uncommon, but well documented origin of this malignant condition with radiography signs, different from intramedullary growing tumours. Imaging modalities like CT or MRI supply proof of macroscopically intact endosteal cortical surface and free medullary cavity in long bones affected by this periosteal type of malignancy. Definite confirmation is valid after a careful microscopic investigation of the resected specimen. The prognosis of this type of Ewing's sarcoma may be favourable than that of the central type. Early diagnosis and therapy are thus essential. A clinical survey of six observations is given. (orig.).
Energy Technology Data Exchange (ETDEWEB)
To utilize ethanol from agricultural residue as a fuel in diesel engines, a dual-fuel engine was developed. The engine, which was equipped with a system to electrically control diesel and alcohol flow rates, met basic requirements of a tractor engine, including engine speed control and setting of the torque curve. However, engine knock due to alcohol was a significant drawback. A diesel injection pump with a timing and flow rate control system was adapted, and the effect of injection timing on combustion and performance was investigated. It was observed that the timing control was effective in reducing engine knock caused by rapid alcohol combustion. (author)
1996-04-01
NMR study of one-dimensional ionic conductor with hollandite-type structure (IV) Rb-priderite
International Nuclear Information System (INIS)
Conduction properties of Rb"+ ion in Rb-Al-priderite and K"+ ion and Rb"+ ion in (K,Rb)-Al-priderite, were investigated by NMR using "2"7Al in the framework as a probe. Size effect was observed remarkably in the activation energies. Frequency dependence of T_1 in Rb-Al-priderite at a low temperature indicates that the relaxation behavior of "2"7Al in Rb-Al-priderite can be described by the continuum model. Barrier height distributions and 'attempt frequencies' in both samples obtained by a curve-fitting method are discussed in comparison with those of K-Al-priderite. (orig.).
1985-08-18
Magnetic fluctuation measurement in Sino United Spherical Tokamak plasma
International Nuclear Information System (INIS)
To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)
2007-07-01
Magnetic behavior in defect-perovskites RTa{sub 3}O{sub 9} (R=Nd,Eu and Ho)
Energy Technology Data Exchange (ETDEWEB)
Magnetic behavior in three compounds RTa{sub 3}O{sub 9} (R = Nd, Eu and Ho) with defect-perovskite structures has been investigated by DC magnetic susceptibility. The susceptibility of NdTa{sub 3}O{sub 9} shows strong influence of crystal field. For EuTa{sub 3}O{sub 9} a typical Van Vleck paramagnetism has been observed. HoTa{sub 3}O{sub 9} obeys a Curie-Weiss law above 20 K. (orig.) 8 refs.
1998-01-01
Self-magnetically insulated, high-voltage transmission lines are used in inertial confinement fusion particle accelerators in order to transmit power from the vacuum insulator to the diode. This paper describes a time-dependent 2-D code (MITL) for calculating (for planar or triplate geometries) the motion of test electrons through the tapered input or output convolutes of such lines. MITL results show that the electron canonical momentum in the direction of the flow changes as the electron passes through the convoluted geometry; it is suggested that these electrons lead to losses observed in long self-magnetically insulated lines.
1979-01-01
Landslides affecting sedimentary characteristics of reservoir basin
British Library Electronic Table of Contents (United Kingdom)
Typhoons Aere (2004) and Matsa (2005) caused high nephelometric turbidity in the Shihmen reservoir in northern Taiwan, jeopardizing the operation of the reservoir for several days, and ultimately impacting the living conditions and economy of the downstream residents. The torrential rains caused landslides and debris flows in upland areas, and flowed into riverbeds, likely contributing significantly to the suspended sediment yields in the reservoir. This investigation elucidates how upland landslides affect sediment attributes in the reservoir basin. Study methods including field observations, spatial analysis in GIS and aerial photo interpretation are adopted to trace the sediment sources and contributing factors to the landslide. Torrential rains induced landslides and debris-flows uplan...
2010-01-01
Knock limitations of methane-air mixtures in a turbocharged dual-fuel engine
Energy Technology Data Exchange (ETDEWEB)
Knock limitations are investigated using natural gas, with diesel pilot ignition, as a fuel for the 3406 DI-TA Caterpillar diesel engine. Thermodynamic properties at TDC are generated by computer and compared with experimental results. Exhaust emissions are analyzed. A comparison is made of dual-fuel operation relative to diesel. Observations are made to determine the onset of knock. The onset of knock is characterized as a function of engine speed, load, inlet manifold temperature, and air-fuel ratio (A/F). The conditions at the inset of knock are determined using cylinder pressure data. The most efficient operating range is determined with knock avoidance as a prime parameter.
1987-01-01
International Nuclear Information System (INIS)
It has been found out that 30HGSNA steel undergo cracking under action of stresses in aqueous solutions containing oxygen, while it show high resistance in deoxidated solutions. The purpose of such phenomena is the existence of sulfur inclusions in steel which are a centers of denting corrosion. That points acting as a stresses concentrators where pH factor decreases including hydrogen formation and its absorption in the metal. That mechanism is the main purpose of brittle steel cracking observed in oxygen rich solutions. (author).
1995-05-17
Interaction between flavonoid, quercetin and surfactant aggregates with different charges
British Library Electronic Table of Contents (United Kingdom)
The interactions of flavonoid, quercetin with sodium dodecyl sulfate (anionic surfactant) and cetyltrimethyl ammonium bromide (cationic surfactant) micelles were investigated. The average location site of quercetin in different micelles was determined by the cyclic voltammetry method with the aid of molecular optimization. The interaction parameters of quercetin with micelles of different charges such as binding constant K and normal binding energy DG were calculated. Furthermore, the morphologic change of the SDS and CTAB spherical micelles and rod-like micelles upon their interaction with quercetin was also observed.
2006-01-01
Influence of scattering on superluminescence in composites dye solution ? nanoparticles
British Library Electronic Table of Contents (United Kingdom)
Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the optical properties of the laser beam propagation channel are transformed when low-power (20?mW) cw laser radiation passes through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle density in the laser beam center, on which diffraction of laser radiation is observed.
2011-01-01
Influence of scattering on superluminescence in composites dye solution - nanoparticles
Spectral and energy luminescence characteristics of R6G dye solutions in ethanol with addition of Ag nanoparticle suspensions in different aggregate states are experimentally investigated. It is demonstrated that incorporation of non-aggregated and aggregated nanoparticles causes the superluminescence thresholds in R6G solutions to decrease. It is established that the optical properties of the laser beam propagation channel are transformed when low-power (20 mW) cw laser radiation passes through the suspension of nanoparticles. This is manifested through the occurrence of a region with enhanced nanoparticle density in the laser beam center, on which diffraction of laser radiation is observed.
2011-09-01
Gravitational Waves from Collapsing Domain Walls
We study the production of gravitational waves from cosmic domain walls created during phase transition in the early universe. We investigate the process of formation and evolution of domain walls by running three dimensional lattice simulations. If we introduce an approximate discrete symmetry, walls become metastable and finally disappear. We calculate the spectrum of gravitational waves produced by collapsing metastable domain walls. Extrapolating the numerical results, we find the signal of gravitational waves produced by domain walls whose energy scale is around 10^10-10^12GeV will be observable in the next generation gravitational wave interferometers.
2010-01-01
Engineering electromagnetic response of composite terahertz metamaterial with broken symmetry
We proposed and numerically investigated the influence of spatial symmetry on the terahertz frequency region response of composite planar metamaterials based on deformed split ring resonators. Compared with the original simple structures, the composite metamaterials with different spatial symmetries exhibited exotic electromagnetic properties. The electromagnetic response of a specific configuration with C4 symmetry was identical to the structure with simple lattice. Especially, for configurations with broken symmetry, very sharp Drude-like resonances with high quality factor were observed. The electric field and current distribution associated the resonances were analyzed for deep understanding of the underlying physical properties.
2011-09-01
International Nuclear Information System (INIS)
Nanoindentation was performed on a Mo-alloy single crystal to investigate effects of focused ion beam (FIB) milling on mechanical behavior. On a non-FIB-milled surface, pop-ins were observed on all load-displacement curves corresponding to a transition from elastic to plastic deformation. Similar pop-ins were not detected on surfaces subjected to FIB milling. This difference indicates that FIB milling introduces damage that obviates the need for dislocation nucleation during subsequent deformation. A second effect of FIB milling is that it increased the surface hardness. Together, these effects could be the source of the size effects reported in the literature on micropillar tests.
2007-09-10
International Nuclear Information System (INIS)
Polymer composites are used in numerous applications. In spite of this fact, new developments are still under way to explore in other field of application of these materials and to tailor their properties for more extreme condition. A particular emphasis is focused on fillers content is summarized. Some steps towards the functionally graded materials are illustrated. The FT-IR spectroscopic studies revealed the information about curing of epoxy with fillers. It was observed that mechanical properties like tensile strength, hardness etc get enhanced up with filler contents. The effect of the different formulations were investigated and discussed for optimum process condition. (author)
1398-01-01
Damage mechanism in high temperature fatigue of alloy 800 H
Energy Technology Data Exchange (ETDEWEB)
In order to investigate the influence of grain boundary cavities on the life time of Alloy 800 H various fatigue tests have been performed at 800/sup 0/C. Cavity formation has been observed only in asymmetrical tests. Compared to the corresponding symmetrical tests, the cyclic life time is shorter. As the cavitation damage increases, the ratio of life times in vacuum and in air steadily decreases from an initial value of 5. In extreme cases it can reach a value close to 1. In this case, cavitation damage dominates over the usual damage mechanism, which is cracks from the surface.
1986-09-01
Corrosion and protection of magnesium alloy AZ31D by a new conversion coating
Energy Technology Data Exchange (ETDEWEB)
A chromium-free conversion coating for magnesium alloys were described. The conversion coating could be obtained when AZ31D magnesium alloy was immersed in a solution containing a manganese salt, phosphate and an inhibitor. Corrosion resistance of the chemical conversion coating was evaluated by anodizing polarization curve and salt immersion. XRD analysis showed that the conversion coating was mainly composed of Mn{sub 3}(PO{sub 4}){sub 2}. The morphology of the coating is observed by using SEM. The effect of electrolyte pH and concentration of inhibitor on coating growth are investigated. (orig.)
2003-07-01
Energy Technology Data Exchange (ETDEWEB)
Hydrogenolysis reactions of a mixture of coal liquid and coal liquefaction residue were carried out using red mud - sulfur or Co-Mo/Al{sub 2}O{sub 3} catalyst. The effect of deashing treatment of coal liquefaction residue were also investigated. Notable synergistic effects such as the increase of n-hexane soluble and the decrease of dichloromethane insoluble were observed only with the hydrogenolysis of the basic fraction of coal liquid and nondeashed coal liquefaction residue using red mud-sulfur catalyst. 4 refs., 2 figs., 2 tabs.
1994-12-31
Aqueous radioactive waste bituminization
International Nuclear Information System (INIS)
The bituminzation of decontamination and ion exchange resin stripping wastes with four grades of asphalt was investigated to determine the effects of asphalt type on the properties of the final products. All waste forms deformed readily under light loads indicating they would flow if not restrained. It was observed in all cases that product leaching rates increased as the hardness of the asphalt used to treat the waste increased. If bituminization is adopted for any Ontario Hydro aqueous radioactive wastes they should be treated with soft asphalt to obtain optimum leaching resistance and mechanical stability during interim storage should be provided by a corrosion resistant container.
5049-01-01
Application of the neutron television fluoroscopic system to neutron computed tomography
Energy Technology Data Exchange (ETDEWEB)
Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).
1984-10-01
Application of the neutron television fluoroscopic system to neutron computed tomography
Energy Technology Data Exchange (ETDEWEB)
Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter.
1984-10-01
British Library Electronic Table of Contents (United Kingdom)
We have measured the frequency-dependent dielectric function of semi-crystalline polybutylene terephthalate (PBT) in the terahertz region between 100?GHz and approximately 2.8?THz. A characteristic band is observed around 2.38?THz. The intensity of this band is a good indicator of the degree of crystallinity of the different samples. A potential assignment of this band is proposed, based on the comparison with spectroscopic data of the structurally very similar polyethylene terephtalate (PET). Furthermore, the frequency-dependent index of refraction of PBT reveals more insight about the morphology and different thermal history of the samples under investigation.
2011-01-01
An influence of ion bombardment on plasma nitriding process of Ti6Al14V alloy at 843 K temperature
International Nuclear Information System (INIS)
This work presents results of investigations on d.c. glow discharge nitriding of #alpha#+#beta# Ti-6Al-4V titanium alloy. The treatment was performed at 843 K in nitrogen-hydrogen atmosphere, pressure 300 Pa. Special attention was paid to nitriding mechanism and determination of the role of ion bombarding in nitriding process of titanium alloys. Produced as a result of d.c. plasma nitriding surface layers were subjected to macroscopic observations, microstructure studies, microhardness testing and X-ray analysis. (author)
2004-06-20
An application of the neutron television fluoroscopic system to neutron computed tomography
International Nuclear Information System (INIS)
Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).
1984-10-01
Adiabatic Rormation of a Matched-beam Distribution for an Alternating-gradient Quadrupole Lattice
Energy Technology Data Exchange (ETDEWEB)
The formation of a quasiequilibrium beam distribution matched to an alternating-gradient quadrupole focusing lattice by means of the adiabatic turn-on of the oscillating focusing field is studied numerically using particle-in-cell simulations. Quiescent beam propagation over several hundred lattice periods is demonstrated for a broad range of beam intensities and vacuum phase advances describing the strength of the oscillating focusing field. Properties of the matched-beam distribution are investigated. In particular, self-similar evolution of the beam density profile is observed over a wide range of system parameters. The numerical simulations are performed using the WARP particle-in-cell code.
2010-02-02
AAR in concrete of Asejire spillway (OYO state - Nigeria)
Energy Technology Data Exchange (ETDEWEB)
The Asejire dam at Ibadan, Nigeria was constructed in the late sixties for the purpose of providing water for the city of Ibadan (presently about 4,5 million inhabitants). It is located on the Oshun river approximately fifteen miles from the city. In 1982 cracks were observed on the wing walls and although these continued to develop, no attempt was made at that time to investigate their causes and no repair was carried out. In 1989 the SGI ENGINEERING Group of Geneva, Switzerland was appointed as the consultant for the complete refurbishment of the Asejire water scheme. The consortium Degremont-Poat-Clemessy was awarded the contract for the project. The African Development Bank and the Nigerian Government have provided the loan to finance the project.
1995-12-31
A review of the probabilistic aspects of localized corrosion
Energy Technology Data Exchange (ETDEWEB)
Localized corrosion has a stochastic character by nature. This character leads to an observed random behavior: fluctuations of the free potential, fluctuations of the current when a constant potential is maintained. This random signal, which is similar to an electric noise, can be analyzed either in the time domain by counting the events or in the frequency domain by measuring the power spectral density of the electrochemical noise. The experimental techniques developed for investigating the localized corrosion on the probabilistic point of view, i.e., statistical counting and power spectral density measurements, are discussed. Then the experimental results reported in the literature are reviewed in order to see what kind of parameters are accessible and how they can be related to the localized corrosion processes.
1990-04-01
Energy Technology Data Exchange (ETDEWEB)
Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis. Methods: At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda. Results and conclusion: The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor ...
2006-08-15
Laser flash effects on chromatic discrimination in monkeys. Final report, April 1986-June 1987
Energy Technology Data Exchange (ETDEWEB)
Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown ...
1987-10-01
International Nuclear Information System (INIS)
Little clinical evidence has been provided to show the minimization of radiation resistance of tumors using high linear energy transfer radiation. We therefore investigated the radiobiological and molecular pathological aspects of carbon beam therapy. A total of 27 patients with squamous cell carcinoma (SCC) of the cervix were treated using a carbon beam and 50 control patients with SCC of the cervix using a photon beam. The expression of Ki-67, p53, and p27 proteins before radiotherapy and 5 and 15 days after therapy initiation were investigated using immunohistochemistry. Similar changes were observed in Ki-67 labeling index (LI) and p53 LI during carbon and photon beam therapies. However, for carbon beam therapy, the mean p27 LI significantly decreased from 25.2% before treatment to 18.6% on the 5th day after treatment initiation, followed by a significant increase to 36.1% on the 15th day. In contrast, for photon beam ...
2008-09-01
International Nuclear Information System (INIS)
Development and deployment of small-scale nuclear power reactors and their maintenance, monitoring, and control are part of the mission under the Small Modular Reactor (SMR) program. The objectives of this NERI-consortium research project are to investigate, develop, and validate advanced methods for sensing, controlling, monitoring, diagnosis, and prognosis of these reactors, and to demonstrate the methods with application to one of the proposed integral pressurized water reactors (IPWR). For this project, the IPWR design by Westinghouse, the International Reactor Secure and Innovative (IRIS), has been used to demonstrate the techniques developed under this project. The research focuses on three topical areas with the following objectives. Objective 1 - Develop and apply simulation capabilities and sensitivity/uncertainty analysis methods to address sensor deployment analysis and small grid stability issues. Objective 2 - Develop and test an ...
2009-02-23
Radiation damage and hardening of molybdenum in 29 MeV alpha particle straggling zone
International Nuclear Information System (INIS)
Technique, allowing to investigate straggling zone (full braking) from high-energy charged particles in detail, is described. Experimental results on investigation of efective structure, created in polycrystalline molybdenum (99.97%) within 29 MeV alpha-particles straggling zone for fluences from 3.8x10"1"9 up to 3.7x10"2"1 #alpha#/m"2 by methods of microhardness (H_#mu#, X-ray structural analysis (#DELTA#a/a) and transparent electron microscopy (TEM), are presented. It is determined, that for doses from 3.8x10"2"0 #alpha#/m"2 and higher, at #approx#6 MeV energy, molybdenum ''softening'' is observed, H_#mu# curve within straggling zone is well described by alloyage calculated profile. #DELTA#a/a measurements within straggling zone are well described by damage profile. TEM-investigations have shown the developed defective structure even within molybdenum ''softening'' range.
Heat and momentum transport in self-sustained oscillatory viscous flows
Energy Technology Data Exchange (ETDEWEB)
Heat and momentum transport in self-sustained oscillatory viscous flows is investigated by direct numerical simulation using the spectral element method. Above a critical Reynolds number, these flows bifurcate to a time-periodic, self-sustained oscillatory state. Traveling waves are observed, even at moderately low Reynolds numbers, inducing self-sustained oscillations that result in very well-mixed flows, which, in turn, lead to convective heat transfer augmentation. These oscillatory states are investigated and correlations between the time- and space-averaged Nusselt and Reynolds numbers are obtained. The transport phenomena of heat and momentum due to the oscillatory components of the flow are analyzed by looking at the phase portraits of velocity and temperature, investigating the behavior of the terms involving their fluctuations, as well as considering the correlation coefficients between the ...
1992-11-01
Energy Technology Data Exchange (ETDEWEB)
It was to be investigated why inexplicable cracking occurred in plain stainless austenitic steel pipes of heat exchangers in discrete sites of the inner surface exposed to acid even with anodic corrosion protection, and what countermeasures must be taken. The following materials were investigated: X 6 CrNiTi 18 10 and X 6 CrNiMoTi 17 12 2. The influence of mechanical vibrations on passive film formation and destruction was investigated in unconstrained pipes and pipes constrained at one end in conditions of anodic protection at frequencies of 0 to 160 Hz and temperatures of 98 to 130 degrees Centigrade in 98% sulphuric acid. The authors were unable to reconstruct the cracks observed in practical operation in anodically protected heat exchanger pipes of stainless austenitic steel. (orig./MM). 5 refs., 2 tabs., 71 figs.
1990-09-20
Strategic principles workshops: Discussion drafts and workshop notes
Energy Technology Data Exchange (ETDEWEB)
The Office of Civilian Radioactive Waste-Management in the Department of Energy (DOE) is responsible for disposing of this nation`s spent fuel and high-level radioactive waste in a manner that protects the health and safety of the public and the quality of the environment. Although embodied in the Federal repository program that began with studies in the late 1950s, this mission was explicitly established by the Nuclear Waste Policy Act of 1982 and reaffirmed by the Nuclear Waste Policy Amendments Act of 1987. To fulfill our mission, we are developing a waste management system consisting of a geologic repository for permanent disposal deep beneath the surface of the earth, a facility for monitored retrievable storage, and a system for transporting the waste. This discussion draft was developed to help involve parties affected by or interested in the waste-management program in the formulation of the basic principles on which the program will be ...
1991-09-01
Energy Technology Data Exchange (ETDEWEB)
Test Area North (TAN) was a site of the Aircraft Nuclear Propulsion (ANP) Project of the U.S. Air Force and the Atomic Energy Commission. Its Cold War mission was to develop a turbojet bomber propelled by nuclear power. The project was part of an arms race. Test activities took place in five areas at TAN. The Assembly & Maintenance area was a shop and hot cell complex. Nuclear tests ran at the Initial Engine Test area. Low-power test reactors operated at a third cluster. The fourth area was for Administration. A Flight Engine Test facility (hangar) was built to house the anticipated nuclear-powered aircraft. Experiments between 1955-1961 proved that a nuclear reactor could power a jet engine, but President John F. Kennedy canceled the project in March 1961. ANP facilities were adapted for new reactor projects, the most important of which were Loss of Fluid Tests (LOFT), part of an international safety program for commercial power reactors. Other projects ...
2005-02-01
Energy Technology Data Exchange (ETDEWEB)
The mission of the Emerging Technologies thrust area at Lawrence Livermore National Laboratory is to help individuals establish technology areas that have national and commercial impact, and are outside the scope of the existing thrust areas. We continue to encourage innovative ideas that bring quality results to existing programs. We also take as our mission the encouragement of investment in new technology areas that are important to the economic competitiveness of this nation. In fiscal year 1992, we have focused on nine projects, summarized in this report: (1) Tire, Accident, Handling, and Roadway Safety; (2) EXTRANSYT: An Expert System for Advanced Traffic Management; (3) Odin: A High-Power, Underwater, Acoustic Transmitter for Surveillance Applications; (4) Passive Seismic Reservoir Monitoring: Signal Processing Innovations; (5) Paste Extrudable Explosive Aft Charge for Multi-Stage Munitions; (6) A Continuum Model for Reinforced Concrete ...
1993-03-01
Double-Edge Molecular Measurement of Lidar Wind Profiles in the VALID Campaign
We have developed a transportable container based direct detection Doppler lidar based on the double-edge molecular technique. The pulsed solid state system was built at the University of Geneva. It was used to make range resolved measurements of the atmospheric wind field as part of the VALID campaign at the Observatoire de Haute Provence in Provence, France in July 1999. Comparison of our lidar wind measurements, which were analyzed without knowledge of the results of rawinsonde measurements made under the supervision of ESA, show good agreement with these rawinsondes. These are the first Doppler lidar field measurements made with an eyesafe direct detection molecular-based system at 355 nm and serve as a demonstrator for future spaceborne direct detection wind systems such as the Atmospheric Dynamics mission. Winds are an important contributor to sea surface temperature measurements made with the Tropical Rainfall Measuring Mission (TRMM) ...
2000-01-01
Development of a phoswich detector to detect neutrons in the charged-particle mixed field
Energy Technology Data Exchange (ETDEWEB)
Manned-space missions bring an exposure due to corpuscular radiations of which nature is quite different from what we encounter in the ground environment. In the space environment, many secondaries are produced through interactions of cosmic ray primaries with the spacecraft wall and other surrounding materials. Among this large variety of radiation components in the space, the contribution of neutrons to the radiation exposure of astronauts has remained to be studied. Up to today, efforts to measure neutron dose equivalent have been made using passive detector systems. Considering uncertainties involved in current measurements and estimations of high energy neutrons, and their increasing importance for future manned missions, it is necessary to measure neutron spectrum in the spacecraft under realistic conditions. The neutron spectra have never been measured on board a spacecraft, because the neutron measurement requires to discriminate ...
1997-07-01
Defense Threat Reduction Agency Radiochemical Needs
International Nuclear Information System (INIS)
The United States Government (USG) first developed nuclear forensics-related capabilities to analyze radiological and nuclear materials, including underground nuclear test debris and interdicted materials. Nuclear forensics is not a new mission for Department of Defense (DoD). The department's existing nuclear forensics capability is the result of programs that span six (6) decades and includes activities to assess foreign nuclear weapons testing activities, monitor and verify nuclear arms control treaties, and to support intelligence and law enforcement activities. Today, nuclear forensics must support not only weapons programs and nuclear smuggling incidents, but also the scientific analysis and subsequent attribution of terrorists' use of radiological or nuclear materials/devices. Nuclear forensics can help divulge the source of origin of nuclear materials, the type of design for an interdicted or detonated device, as well as the pathway of the materials or ...
2009-08-19
Cleanup at Los Alamos National Laboratory - the challenges - 9493
Energy Technology Data Exchange (ETDEWEB)
This paper provides an overview of environmental cleanup at the Los Alamos National Laboratory (LANL) and some of the unique aspects and challenges. Cleanup of the 65-year old Department of Energy Laboratory is being conducted under a RCRA Consent Order with the State of New Mexico. This agreement is one of the most recent cleanup agreements signed in the DOE complex and was based on lessons learned at other DOE sites. A number of attributes create unique challenges for LANL cleanup -- the proximity to the community and pueblos, the site's topography and geology, and the nature of LANL's on-going missions. This overview paper will set the stage for other papers in this session, including papers that present: Plans to retrieve buried waste at Material Disposal Area B, across the street from oen of Los Alamos' commercial districts and the local newspaper; Progress to date and joint plans with WIPP for disposal of the remaining inventory of ...
2008-01-01
A preliminary stage configuration for a low pressure nuclear thermal rocket (LPNTR)
Energy Technology Data Exchange (ETDEWEB)
A low pressure nuclear thermal rocket (LPNTR) is configured to meet the requirements of a nuclear stage for manned Mars exploration. Safety, reliability and performance are given equal consideration in selecting the stage configuration. Preliminary trade studies are conducted to size the engine thrust and determine the thrust chamber pressure. A weight breakdown and mechanical configuration for the selected LPNTR concept are defined. A seven engine stage configuration is selected which gives a two engine out capability and eliminates the need for engine gimbaling. The stage can be ground assembled and launched as a unit including tankage for trans Earth injection and Earth orbital capture. The tankage is configured to eliminate the need for an inert shield. The small engine will be cheaper to develop than a single engine providing full thrust, and will be compatible with stages for Earth orbital, Lunar and deep space missions. Mission analyses ...
1990-01-01
Effect of pitting corrosion on local strength of hold frames of bulk carriers (1st report)
Energy Technology Data Exchange (ETDEWEB)
Firstly, pitting corrosion observed on hold frames in cargo holds of bulk carriers which exclusively carry coal and iron ore has been investigated in detail. It was shown that the shape of the corrosion pits observed on them is a circular cone and the ratio of the diameter to the depth is in the range between 8 to 1 and 10 to 1, which is different from the trend observed for the bottom shell of the oil tanker where the ratio is in the range between 4 to 1 and 6 to 1. Secondly, a series of tensile tests has been conducted to investigate the effect of pitting corrosion on tensile strength of members. It was pointed out that the tensile strength decreases gradually and the total elongation decreases drastically with the increase of the thickness loss due to pitting corrosion. The reduction of the tensile strength of the members with pitting corrosion is larger than that of members with ...
2004-09-01
The U.S. Support Program to IAEA Safeguards - How It Works
Energy Technology Data Exchange (ETDEWEB)
The U.S. Support Program to International Atomic Energy Agency (IAEA) Safeguards (USSP) was established in 1977 to transfer US technology and expertise to assist the IAEA Department of Safeguards because its limited budget and scope would not allow for R&D activities and the procurement of specialized or customized equipment. Over the years, the USSP and the Department of Safeguards have worked together continuously to develop and improve processes for requesting, selecting, and managing projects that support the Safeguards verification mission. This paper will discuss the main USSP processes for accepting and processing Safeguards requests, and managing and reporting task progress.
2008-07-13
SKA in VLBI Impact on Studies of Small Scale Structures in Active Galactic Nuclei
We discuss the advantages which the next generation interferometer SKA (the Square Kilometer Array) will bring for Very Long Baseline Interferometry (VLBI) at centimeter wavelengths. With a sensitivity to micro-Jy level flux density, a brightness temperature limit of about 10.000 K, and an expected dynamic range in future VLBI maps of better than 1.000.000, the impact of SKA on the research of compact extragalactic radio sources and their energetic jets will be very strong. We discuss some consequences, including a possible combination of SKA with future space VLBI missions.
1999-01-01
SIMON Host Computer System requirements and recommendations
Energy Technology Data Exchange (ETDEWEB)
Development Service Order {number_sign}90025 requested recommendations for computer hardware, operating systems, and software development utilities based on current and future SIMON software requirements. Since SIMON`s main objective is to be dispatched on missions by an operator with little computer experience, ``user friendly`` hardware and software interfaces are required. Other design criteria include: a fluid software development environment, and hardware and operating systems with minimal maintenance requirements. Also, the hardware should be expandable; extra processor boards should be easily integrated into the existing system. And finally, the use of well established standards for hardware and software should be implemented where practical.
1990-11-29
Energy Technology Data Exchange (ETDEWEB)
This document outlines the significant accomplishments of fiscal year 1998 for the Tank Waste Remediation System (TWRS) Project Hanford Management Contract (PHMC) team. Opportunities for improvement to better meet some performance expectations have been identified. The PHMC has performed at an excellent level in administration of leadership, planning, and technical direction. The contractor has met and made notable improvement of attaining customer satisfaction in mission execution. This document includes the team`s recommendation that the PHMC TWRS Performance Expectation Plan evaluation rating for fiscal year 1998 be an Excellent.
1998-09-04
Nuclear propulsion systems for orbit transfer based on the particle bed reactor
International Nuclear Information System (INIS)
The technology of nuclear direct propulsion orbit transfer systems based on the Particle Bed Reactor (PBR) is described. A 200 megawatt illustrative design is presented for LEO to GEO and other high #DELTA#V missions. The PBR-NOTV can be used in a one-way mode with the shuttle or an expendable launch vehicle, e.g., the Titan 34D7, or as a two-way reusable space tug. In the one-way mode, payload capacity is almost three times greater than that of chemical OTV's. PBR technology status is described and development needs outlined.
1987-01-12
Midwest Superconductivity Consortium: 1994 Progress report
Energy Technology Data Exchange (ETDEWEB)
The mission of the Midwest Superconductivity Consortium, MISCON, is to advance the science and understanding of high {Tc} superconductivity. During the past year, 27 projects produced over 123 talks and 139 publications. Group activities and interactions involved 2 MISCON group meetings (held in August and January); with the second MISCON Workshop held in August; 13 external speakers; 79 collaborations (with universities, industry, Federal laboratories, and foreign research centers); and 48 exchanges of samples and/or measurements. Research achievements this past year focused on understanding the effects of processing phenomena on structure-property interrelationships and the fundamental nature of transport properties in high-temperature superconductors.
1995-01-01
Melter system technology testing for Hanford Site low-level tankwaste vitrification
Energy Technology Data Exchange (ETDEWEB)
Following revisions to the Tri-Party Agreement for Hanford Site cleanup, which specified vitrification for Complete melter feasibility and system operability immobilization of the low-level waste (LLW) tests, select reference melter(s), and establish reference derived from retrieval and pretreatment of the radioactive LLW glass formulation that meets complete systems defense wastes stored in 177 underground tanks, commercial requirements (June 1996). Available melter technologies were tested during 1994 to 1995 as part of a multiphase program to select reference Submit conceptual design and initiate definitive design technologies for the new LLW vitrification mission.
1996-05-03
Idaho National Laboratory 2013-2022 Ten-Year Site Plan
Energy Technology Data Exchange (ETDEWEB)
The Idaho National Laboratory (INL) Ten-Year Site Plan (TYSP) describes the strategy for accomplishing the long-term objective of transforming the laboratory to meet Department of Energy (DOE) national nuclear research and development (R&D) goals, as outlined in DOE strategic plans. The plan links R&D mission goals and INL core capabilities with infrastructure requirements (single- and multi-program), establishs the 10-year end-state vision for INL complexes, and identifies and prioritizes infrastructure needs and capability gaps. The TYSP serves as the basis for documenting and justifying infrastructure investments proposed as part of the FY 2013 budget formulation process.
2011-06-01
Hermetically sealed aluminum electrolytic capacitor
Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, much larger and heavier packages of tantalum capacitors are used. A hermetically sealed aluminum capacitor has been developed under NASA-MSFC SBIR contracts. This capacitor contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated at 250 to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and low internal pressure. Electrolyte chemistry and seal engineering concepts will be discussed.
1995-04-01
Conversion of selected military forces to the use of metric measurement units
Conversion of the United States military to the International System of measurement units is in the very early stages. Little formal planning has been done to articulate the management required to complete the conversion of operational Army and Air Force units. For those operational forces tasked to provide continuous combat readiness throughout metrication, management problems associated with the conversion are particularly difficult because of the nature of these assigned missions. This is the case for the 82nd Airborne Division ready brigade force (DRB) and the Military Airlift Command (MAC) strategic airlift system operating the C-141 and C-5A aircraft.
1976-06-01
Connectivity in the Astronomy Digital Library
The Astrophysics Data System (ADS) provides an extensive system of links between the literature and other on-line information. Recently, the journals of the American Astronomical Society (AAS) and a group of NASA data centers have collaborated to provide more links between on-line data obtained by space missions and the on-line journals. Authors can now specify which data sets they have used in their article. This information is used by the participants to provide the links between the literature and the data. The ADS is available at: http://ads.harvard.edu
2006-01-01
Coal Corporation of Victoria. Annual report 1989-90. [Australia - Victoria
Energy Technology Data Exchange (ETDEWEB)
The Coal Corporation of Victoria's mission is to initiate, facilitate and co-ordinate brown coal-based developments, other than for electricity generation, to provide maximum long-term benefits to Victoria including new jobs, new technology, new investment and new products, within sound environmental parameters. The marketing of brown coal products is vigorously undertaken to provide the financial and business base for the Corporation. This report contains a review of the Corporation's activities and achievements during 1989/90.
1990-01-01
PAMELA is a space telescope orbiting around the Earth since June 2006. The scientific objectives addressed by the mission are the measurement of the antiprotons and positrons spectra in cosmic rays, the hunt for anti-nuclei as well as the determination of light nuclei fluxes from Hydrogen to Oxygen in a wide energy range and with very high statistics. In this paper the charge discrimination capabilities of the PAMELA Time-Of-Flight system for light nuclei, determined during a beam test calibration, will be presented.
2008-01-01
International Nuclear Information System (INIS)
Full text: Lung cancer is responsible for most of the cancer related deaths and calls for new approaches to control the menace. In the present study chemopreventive efficacy of curcumin and quercetin was investigated against benzo(a)pyrene (BP) induced lung carcinogenesis. The mice were segregated into five groups which included normal control, BP treated, BP+curcumin treated, BP+quercetin treated and BP+curcumin+quercetin treated groups. The morphological and histological analyses of tumor nodules confirmed lung carcinogenesis, after 22 weeks of single i.p. injection of BP at a dose of 100 mg/Kg body weight to mice. Tumor incidence and tumor multiplicity were observed to be 88% and 1.75, respectively in the BP treated mice. A statistically significant increase in the uptake of "3H thymidine indicative of increased DNA synthesis which in turn is the marker of uncontrolled cancer cell proliferation, was observed in the lung ...
Trends in robotics: A summary of the Department of Energy`s critical technology roadmap
Energy Technology Data Exchange (ETDEWEB)
Technology roadmaps serve as pathways to the future. They call attention to future needs for research and development; provide a structure for organizing technology forecasts and programs; and help communicate technological needs and expectations among end users and the research and development (R and D) community. Critical Technology roadmaps, of which the Robotics and Intelligent Machines (RIM) Roadmap is one example, focus on enabling or cross-cutting technologies that address the needs of multiple US Department of Energy (DOE) offices. Critical Technology roadmaps must be responsive to mission needs of the offices; must clearly indicate how the science and technology can improve DOE capabilities; and must describe an aggressive vision for the future of the technology itself. The RIM Roadmap defines a DOE research and development path for the period beginning today, and continuing through the year 2020. Its purpose is to identify, select and develop objectives ...
1998-08-10
The Center for Environmental Technology Innovative Technology Screening Process
Energy Technology Data Exchange (ETDEWEB)
The Center for Environmental Technology`s (CET) mission is to provide a fully integrated system for accelerated evaluation, development, commercialization, and public acceptance of creative environmental solutions which match the foremost demands in today`s environmentally sensitive world. In short, CET will create a means to provide quick, effective solutions for environmental needs. To meet this mission objective, CET has created a unique and innovative approach to eliminating the usual barriers in developing and testing environmental technologies. The approach paves the way for these emerging, cutting-edge technologies by coordinating environmental restoration and waste management activities of industry, universities, and the government to: efficiently and effectively transfer technology to these users, provide market-driven, cost-effective technology programs to the public and DOE, and aid in developing innovative ideas by initiating ...
1995-02-01
Oak Ridge National Laboratory Waste Management Plan, fiscal year 1994. Revision 3
Energy Technology Data Exchange (ETDEWEB)
US Department of Energy (DOE) Order 5820.2A was promulgated in final form on September 26, 1988. The order requires heads of field organizations to prepare and to submit updates on the waste management plans for all operations under their purview according to the format in Chap. 6, {open_quotes}Waste Management Plan Outline.{close_quotes} These plans are to be submitted by the DOE Oak Ridge Operations Office (DOE-ORO) in December of each year and distributed to the DP-12, ES&H-1, and other appropriate DOE Headquarters (DOE-HQ) organizations for review and comment. This document was prepared in response to this requirement for fiscal year (FY) 1994. The Oak Ridge National Laboratory (ORNL) waste management mission is reduction, collection, storage, treatment, and disposal of DOE wastes, generated primarily in pursuit of ORNL missions, in order to protect human health and safety and the environment. In carrying out this ...
1993-12-01
Oak Ridge National Laboratory Core Competencies
Energy Technology Data Exchange (ETDEWEB)
A core competency is a distinguishing integration of capabilities which enables an organization to deliver mission results. Core competencies represent the collective learning of an organization and provide the capacity to perform present and future missions. Core competencies are distinguishing characteristics which offer comparative advantage and are difficult to reproduce. They exhibit customer focus, mission relevance, and vertical integration from research through applications. They are demonstrable by metrics such as level of investment, uniqueness of facilities and expertise, and national impact. The Oak Ridge National Laboratory (ORNL) has identified four core competencies which satisfy the above criteria. Each core competency represents an annual investment of at least $100M and is characterized by an integration of Laboratory technical foundations in physical, chemical, and materials sciences; biological, ...
1994-12-01
Modeling human risk: Cell & molecular biology in context
Energy Technology Data Exchange (ETDEWEB)
It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high ...
1997-06-01
GOCE, Satellite Gravimetry and Antarctic Mass Transports
In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity ...
2011-03-01
Design and integration of a solar AMTEC power system with an advanced global positioning satellite
Energy Technology Data Exchange (ETDEWEB)
A 1,200-W solar AMTEC (alkali metal thermal-to-electric conversion) power system concept was developed and integrated with an advanced global positioning system (GPS) satellite. The critical integration issues for the SAMTEC with the GPS subsystems included (1) packaging within the Delta 2 launch vehicle envelope, (2) deployment and start-up operations for the SAMTEC, (3) SAMTEC operation during all mission phases, (4) satellite field of view restrictions with satellite operations, and (5) effect of the SAMTEC requirements on other satellite subsystems. The SAMTEC power system was compared with a conventional planar solar array/battery power system to assess the differences in system weight, size, and operations. Features of the design include the use of an advanced multitube, vapor anode AMTEC cell design with 24% conversion efficiency, and a direct solar insolation receiver design with integral LiF salt canisters for energy storage to generate power during the ...
1996-12-31
Accelerating the disposition of transuranic waste from LANL - 9495
Energy Technology Data Exchange (ETDEWEB)
Los Alamos National Laboratory (LANL) was established during World War II with a single mission -- to design and build an atomic bomb. In the 65 years since, nuclear weapons physics, design and engineering have been the Laboratory's primary and sustaining mission. Experimental and process operations -- and associated cleanout and upgrade activities -- have generated a significant inventory of transuranic (TRU) waste that is stored at LANL's Technical Area 54, Material Disposal Area G (MDA G). When the Waste Isolation Pilot Plant (WIPP) opened its doors in 1999, LANL's TRU inventory totaled about 10,200 m{sup 3}, with a plutonium 239-equivalent curie (PE Ci) content of approximately 250,000 curies. By December 2008, a total of about 2,300 m3 (61,000 PE Ci) had been shipped to WIPP from LANL. This has resulted in a net reduction of about 1,000 m{sup 3} of TRU inventory over that time frame. This paper presents progress ...
2009-01-01
An observational and modeling study was performed over the Arabian Gulf region to investigate the coastal circulations and aerosol transport in the area. Climatological data and observations from the United Arab Emirates' Unified Aerosol Experiment were used to develop a better understanding of the complex meteorological processes in the Arabian Gulf region. Climatological data suggests that sea breezes occur on more than 77 percent of days in all months of the year and land breezes occur on more than 70 percent of the days. The occurrence of the sea and land breeze circulations are higher (90-99 percent) during the summer months when large-scale weather patterns are quiescent. Measurements of aerosol concentrations taken during the Unified Aerosol Experiment(2004) experiment are used to investigate aerosols, namely dust, transported in the Arabian Gulf region. Vertical profiles of dust concentration ...
2005-12-01
The Two-Column Aerosol Project (TCAP) Science Plan
Energy Technology Data Exchange (ETDEWEB)
The Two-Column Aerosol Project (TCAP) field campaign will provide a detailed set of observations with which to (1) perform radiative and cloud condensation nuclei (CCN) closure studies, (2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing, (3) extend a previously developed technique to investigate aerosol indirect effects, and (4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) on Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation, and ...
2011-07-27
International Nuclear Information System (INIS)
This study was carried out to evaluate the effects of irradiation (gamma irradiation at dose levels of 0.0, 2.5, 5.0, 10.0 or 20.0 kGy, He-Ne and their combination) on nutritive characteristics of Vicia faba L. seeds (Giza 843). Analyses included levels of anti-nutrients (total phenolic compounds, tannins, phytic acid, trypsin inhibitor and vicine), chemical composition (sugars, crude proteins, fat, dry matter and ash) and fatty acids profile. All treatments caused significant (P<0.05) decreases in the antinutrational factors under investigation. The reduction in the content of tannins and phenolic compounds were more pronounced with He-Ne alone or He-Ne in combination with gamma irradiation. At dose levels 10.0 and 20.0 kGy without or with combination of He-Ne were more efficiency in the reduction of phytic acid content by 24.3, 32.8, 34.5 and 45.5 %, respectively. Also, for trypsin inhibitor activity, the maximum inhibition was observed ...
XPS study of passive films formed on molybdenum-implanted austenitic stainless steels
Energy Technology Data Exchange (ETDEWEB)
Austenitic stainless steels have been implanted with molybdenum ions (Mo[sup +], 100 keV, 2.5 x 10[sup 16] atoms cm[sup -2]). The implanted material has been characterized by XPS and RBS. The implanted region has a thickness of [approx] 1000 A with a maximum molybdenum concentration of [approx] 9 at.% Mo located at [approx] 210 A from the surface. The effects of implanted molybdenum on the passivation of the alloy in 0.5 M H[sub 2]SO[sub 4] have been investigated by electrochemistry and XPS. After XPS analysis the samples were transferred without exposure to air into a glove-box with an inert atmosphere. The electrochemical behaviour of the alloy is significantly modified by the implanted molybdenum. The major effect is that the activation peak disappears. A bilayer structure (outer hydroxide/inner oxide) of the passive film is observed for both the implanted and non-implanted alloys and the thicknesses of the films are similar. On the ...
1992-06-01
XPS study of passive films formed on molybdenum-implanted austenitic stainless steels
International Nuclear Information System (INIS)
Austenitic stainless steels have been implanted with molybdenum ions (Mo"+, 100 keV, 2.5 x 10"1"6 atoms cm"-"2). The implanted material has been characterized by XPS and RBS. The implanted region has a thickness of #approx# 1000 A with a maximum molybdenum concentration of #approx# 9 at.% Mo located at #approx# 210 A from the surface. The effects of implanted molybdenum on the passivation of the alloy in 0.5 M H_2SO_4 have been investigated by electrochemistry and XPS. After XPS analysis the samples were transferred without exposure to air into a glove-box with an inert atmosphere. The electrochemical behaviour of the alloy is significantly modified by the implanted molybdenum. The major effect is that the activation peak disappears. A bilayer structure (outer hydroxide/inner oxide) of the passive film is observed for both the implanted and non-implanted alloys and the thicknesses of the films are similar. On the implanted alloy the outer ...
1991-10-01
The response of quartz crystals coated with thin fatty acid film to organic gases
Energy Technology Data Exchange (ETDEWEB)
We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C{sub 14}), palmitic acid (C{sub 16}), stearic acid (C{sub 18}), and arachidic acid (C{sub 20}) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic ...
1999-07-01
The effect of the alcoholic solvent type on the formation of silica fine particles from alkoxide
Energy Technology Data Exchange (ETDEWEB)
In this paper, we investigated the effect of alcohol solvents (ethanol, n-propanol, and n-butanol) and isomeric alcohol solvents (iso-propanol, iso--butanol, and tert-butanol). In addition, we observed the effect of the mixed alcohol solvents on the particle formation as using a mixture od ethanol and butanol at a ratio od 30/70, 50/50 and 70/30 vol %, respectively. In case of ethanol solvent, particle size of silica showed the smallest and the narrowest size distribution among the various solvent. On the contrary, for the n-butanol solvent, largest broad distribution of particle size was observed. For the synthesis of particles having better spherical morphology and less agglomeration, alcohol solvent having no branches was considered appropriate. When mixed alcohol solvents were used, large silica particles with narrow size distribution were obtained, regardless of the ratio. 8 refs., 5 figs., 1 tab.
2000-04-01
The effect of annealing parameter on corrosion resistance of Zircaloy-2
International Nuclear Information System (INIS)
The effects of equal #SIGMA#Ai for different combinations of the annealing temperature and annealing time on corrosion resistance and evolution of precipitates of Zircaloy-2 were investigated. Nodular corrosion resistance in the out-of-pile corrosion test was degraded with increasing #SIGMA#Ai only when it was increased by extending the annealing time at 894 K but did not depend on #SIGMA#Ai which was increased by raising the annealing temperature for a constant annealing time of 2.5 h. Extensive observation and micro-analysis of precipitates by analytical electron microscope (AEM) suggested the cause of degradation of nodular corrosion resistance to be the remarkable increase in volume fraction of Si-containing precipitates such as Zr_3Si and Zr_2Si, which were observed more frequently in large #SIGMA#Ai only when it was increased by extending the annealing time at 894 K. On the other hand, uniform corrosion resistance was ...
Energy Technology Data Exchange (ETDEWEB)
The investigated hybrid nanocomposite consists of a porous silicon template with electrochemically embedded Ni or Co nanostructures and offers magnetic characteristics which can be tailored by the electrochemical process parameters during fabrication. A twofold magnetic behaviour can be observed, a first one due to the spinmagnetism at magnetic fields below the saturation magnetization of the deposited metals and a second non-saturating term at higher fields (>1 T up to 7 T) above the saturation magnetization. In case of Ni deposited within the pores this non-saturating term shows a paramagnetic characteristic and follows exactly the Curie-Weiss law, whereas for Co/porous silicon samples the temperature dependent magnetization shows some deviations from the Curie Weiss law. In this high field region a difference in the temperature dependence between Ni and Co is observed whereas the non-saturating term does not ...
2009-10-15
International Nuclear Information System (INIS)
We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V #<=# 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R'_H_K is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to have transitioned from ...
2009-07-01
Studies on the Evolution of Silver Nanoparticles in Micelle by UV-Photoactivation
Energy Technology Data Exchange (ETDEWEB)
Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from different ...
2003-12-15
Energy Technology Data Exchange (ETDEWEB)
With an objective to learn reactivity of coal at its surface, surfaces of oxidized coal samples were investigated. Miike coal was oxidized by using {sup 18}O2 in a closed loop system. As the reaction progresses, proportion of CO2 including isotopes increased rapidly as a result of oxidation of CO sites existing in the coal and the newly generated C{sup 18}O sites. The oxidizing reaction progressed via oxygen adsorbing sites generated near the surface, and oxygen containing groups. An FT-IR analysis estimated the depth of the oxidized layer to be 10{mu}m or less from particle surface. The oxidized coal was pulverized to see its surface condition. Functional groups introduced by the oxidation enter into the vicinity of the surface in a form to desorb as CO. CO2 is trapped in inner pores. The coal surface was observed by using an atomic force microscope. No observable openings in the pore structure were discerned on the ...
1996-10-28
Studies on accumulation of uranium by fungus Lentinus sajor-caju
Energy Technology Data Exchange (ETDEWEB)
The untreated, heat- and alkali-treated Lentinus sajor-caju mycelia were used for the recovery of uranium from aqueous solutions. The effect of pH, temperature, initial concentration of UO{sub 2} {sup 2+} ions and contact time parameters were investigated in a batch system. The particles sizes of the fungal mycelia were ranging from 100 to 200 {mu}m. Biosorption equilibriums were established in about 30 min and the correlation regression coefficients show that the adsorption process can be well defined by the Freundlich equation. The alkali treated form had a high biosorption capacity (378 mg/g) than those of the untreated (268 mg/g) and heat-treated fungal mycelia (342 mg/g). Optimum biosorption was observed at pH 4.5 for all the tested fungal preparations and was independent of temperature (5-35 deg. C). In addition, the polarity and surface energy of the fungal biomass film preparations were determined by contact angle measurement. The ...
2006-08-21
Spin correlations in the frustrated square lattice Pb{sub 2}VO(PO{sub 4}){sub 2}
Energy Technology Data Exchange (ETDEWEB)
The new frustrated square-lattice system, Pb{sub 2}VO(PO{sub 4}){sub 2}, has been investigated using polarised neutron scattering. From these studies, made on powdered samples, we have determined the nature of the exchange interactions and the magnetic ordering for this novel quantum magnet. Quantum order from disorder occurs at low temperature, and the ground state observed below the Neel temperature T {sub N}{approx}3.7 K is a collinear antiferromagnet. At room temperature there are no magnetic correlations and it is possible to model the scattering with the V{sup 4+} magnetic form factor. However, at T{approx}20 K, a temperature well into the paramagnetic phase, magnetic correlations are observed, and these spin correlations have been modelled using a high-temperature series expansion. Ferromagnetic nearest-neighbour exchange J {sub 1}{approx}-2 K and antiferromagnetic next-nearest-neighbour exchange J {sub 2}{approx}6.5 ...
2007-03-15
Spark decomposition of SF/sub 6/
Energy Technology Data Exchange (ETDEWEB)
Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into by-products having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that SF/sub 6/, spark-decomposed under specific experimental conditions, can produce cell death. Chemical analysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and by-products. Biological testing of individual by-products or by-product mixtures has indicated that these major decomposition products may not account for the majority of the cell killing effects seen in our assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be produced and accumulate under our specific decomposition conditions and that this ...
1989-07-01
We present new semi-analytical models for the formation of disk galaxies with the purpose of investigating the origin of the near-infrared Tully-Fisher (TF) relation. The models assume that disks are formed by cooling of the baryons inside dark halos with realistic density profiles, and that the baryons conserve their specific angular momentum. Only gas with densities above the critical density given by Toomre's stability criterion is considered eligible for star formation, and a simple recipe for supernovae feedback is included. We emphasize the importance of extracting the proper luminosity and velocity measures from the models, something that has often been ignored in the past. The observed K-band TF relation has a slope that is steeper than simple predictions based on dynamical arguments suggest. Taking the stability related star formation threshold densities into account steepens the TF relation, decreases its scatter, and yields gas mass ...
1999-01-01
Relation between precipitate-free zone width and grain boundary type in 7075-T7 Al alloy
Energy Technology Data Exchange (ETDEWEB)
The effect of grain boundary (GB) type on precipitate-free zone (PFZ) width in friction stir-processed 7075-T7 Al alloy is investigated by transmission electron microscopy (TEM) and stereology. The average half width of PFZs at random GBs is 70.4 {+-} 0.7 nm. For low-angle GBs, an apparent transition of PFZ half width is observed at a misorientation of 11 deg. For coincidence site lattice ({sigma}) GBs, only {sigma}1, {sigma}3 and {sigma}5 have smaller PFZ width than that of random GBs. Crystal-frame stereology is used to recover the GB plane distribution. It is found that the GB plane distribution is relatively isotropic for most {sigma} GBs. Low/high index plane combinations are observed for most {sigma} GBs; furthermore, most {sigma} GBs have both tilt and twist components. The combined results of TEM and stereology suggest that smaller PFZ width is associated only with low {sigma} GBs since the formation and growth of ...
2007-03-15
RF effects on current-driven plasma instabilities
Energy Technology Data Exchange (ETDEWEB)
The Versatile Toroidal Facility (VTF) is a large laboratory plasma machine of 1 meter major radius used to carry out investigations of ionospheric plasma turbulence. Spectral analysis has been performed on plasmas produced by the electron emitters. Interest has focused on the low frequencies below the lower hybrid resonance where ion acoustic and current-convective modes have been observed. Microwaves injected from a 3,000 watt magnetron produce dramatic changes to the low frequency spectrum. First, the parametric decay instability intensifies the ion acoustic modes in the region of plasma heated by the microwaves. Second, the normally dominant current-convective modes are greatly suppressed in the heated region due to the oscillating electric field of the pump wave. When the authors probe beyond the heated region, these two pump wave effects are no longer observed, presumably because the microwaves are denied access to ...
1996-12-31
Preservation of beech and spruce wood by allyl alcohol-based copolymers
International Nuclear Information System (INIS)
Allyl alcohol (AA), acrylonitrile (AN), methyl methacrylate (MMA), monomers and monomer mixtures AA+AN, AA+MMA were used to conserve and consolidate Beech and Spruce. After impregnation, copolymerisation and polymerisation were accomplished by gamma irradiation. The fine structure of wood+polymer(copolymer) composites was investigated by Scanning Electron Microscopy (SEM). It was observed that copolymer obtained from AA+MMA monomer mixture showed the optimum compatibility. The compressional strength and Brinell Hardness Numbers determined for untreated and treated wood samples indicated that the mechanical strength of wood+copolymer composites was increased. It was found that the mechanical strength of the wood samples containing the AA+MMA copolymer was higher than the others. In the presence of P(AA/MMA), at highest conversion, the compressive strength perpendicular to the fibres in Beech and Spruce increased approximately 100 times. The ...
1999-06-01
Phase and microstructural evolution of Ca #alpha#-SiAlON containing elongated grains
International Nuclear Information System (INIS)
Rare earth stabilised #alpha#-SiAlONs are commonly observed with an equiaxed grain morphology. Elongated #alpha#-SiAlON has been observed in some of these systems, however it usually results from special techniques such as pressure sintering. The formation of elongated #alpha#-SiAlON grains during pressureless sintering has been shown to commonly occur in the Ca #alpha#-SiAlON system. Examination of phase and microstructural development in three Ca #alpha#-SiAlON compositions in the temperature range 1400 deg to 1800 deg C showed that phase development and grain growth occurred at different temperatures. It was found that chemical reactions were completed by 1550 deg C, however significant grain growth did not occur at this temperature. Grain growth progressed from 1600 deg C and continued up to 1800 deg C, the maximum temperature investigated. At 1800 deg C, #alpha#-SiAlON was found to be compatible with Aluminium Nitrides ...
1998-09-28
Energy Technology Data Exchange (ETDEWEB)
The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...
1999-05-14
International Nuclear Information System (INIS)
The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...
1999-05-14
On-line video image processing system for real-time neutron radiography
Energy Technology Data Exchange (ETDEWEB)
The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 ...
1983-09-15
Observation of high permittivity in Ho substituted BaZr_0_._1Ti_0_._9O_3 ceramics
International Nuclear Information System (INIS)
The authors observed an extremely high permittivity (#approx#35 000 at T_C) in barium zirconate titanate (BaZr_0_._1Ti_0_._9O_3) ceramics with holmium substitution (1-5 mol %) in Ba site. Careful microstructural investigation and energy dispersive spectroscopy analysis of the 1-2 mol % of Ho substituted ceramics showed the enrichment of a Ho-phase along the grain boundaries with a composition close to the Ho_2Ti_2O_7 pyrochlore. The formation of Ho rich phase resulted in the Maxwell-Wagner polarization mechanism, which leads to this unusually high permittivity. Ceramics with 3 mol % or higher Ho content showed lesser permittivity values compared to 1-2 mol %, probably due to the increase in pyrochlore phase. These high dielectric constant ceramics are useful in nanoscale devices.
2007-07-09
N-body Models of Extended Clusters
We use direct N-body simulations to investigate the evolution of star clusters with large size-scales with the particular goal of understanding the so-called extended clusters observed in various Local Group galaxies, including M31 and NGC6822. The N-body models incorporate a stellar mass function, stellar evolution and the tidal field of a host galaxy. We find that extended clusters can arise naturally within a weak tidal field provided that the tidal radius is filled at the start of the evolution. Differences in the initial tidal filling-factor can produce marked differences in the subsequent evolution of clusters and the size-scales that would be observed. These differences are more marked than any produced by internal evolution processes linked to the properties of cluster binary stars or the action of an intermediate-mass black hole, based on models performed in this work and previous work to date. Models evolved in a ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Rhodopseudomonas viridis was grown in liquid culture at 30 degrees C anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h). The bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1%. Oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor. No growth was observed anaerobically in darkness or in the light when air was present. A variety of additional carbon sources were used to supplement the standard succinate medium, but enhanced stationary-phase cell density was observed only with glucose. Conditions for induction of the photosynthetic reaction center upon the change from microaerophilic to phototrophic growth conditions were investigated and optimized for a mutant functionally defective ...
1989-05-01
DEFF Research Database (Denmark)
The National Survey and Cadastre - Denmark (KMS) has for several years produced gravity anomaly maps over the oceans derived from satellite altimetry. During the last four years, KMS has also conducted airborne gravity surveys along the coast of Greenland dedicated to complement the existing onshore gravity coverage and fill in new data in the very-near coastal area, where altimetry data may contain gross errors. The airborne surveys extend from the coastline to approximately 100 km offshore, along 6000 km of coastline. An adequate merging of these different data sources is important for the use of gravity data especially, when computing geoid models in coastal regions. The presence of reliable marine gravity data for independent control offers an opportunity to study procedures for the merging of airborne and satellite data around Greenland. Two different merging techniques, both based on collocation, are investigated in this paper. Collocation offers a way of ...
2002-01-01
Measurement of the antiproton/proton ratio at few-TeV energies with the ARGO-YBJ experiment
Cosmic ray antiprotons provide an important probe for the study of cosmic-ray propagation in the interstellar space and to investigate the existence of Galactic dark matter. Cosmic rays are hampered by the Moon, therefore a deficit of cosmic rays in its direction is expected (the so-called "Moon shadow"). The Earth-Moon system acts as a magnetic spectrometer. In fact, due to the geomagnetic field the center of the Moon shifts westward by an amount depending on the primary cosmic ray energy. Paths of primary antiprotons are therefore deflected in an opposite sense in their way to the Earth. This effect allows, in principle, the search of antiparticles in the opposite direction of the observed Moon shadow. The ARGO-YBJ experiment, in stable data taking since November 2007 with an energy threshold of a few hundreds of GeV, is observing the Moon shadow with high statistical significance. Using about 1 year data, an upper limit ...
2009-01-01
MRS of normal and impaired fetal brain development
International Nuclear Information System (INIS)
Cerebral maturation in the human fetal brain was investigated by in utero localized proton magnetic resonance spectroscopy (MRS). Spectra were acquired on a clinical MR system operating at 1.5 T. Body phased array coils (four coils) were used in combination with spinal coils (two coils). The size of the nominal volume of interest (VOI) was 4.5 cm"3 (20 mm x 15 mm x 15 mm). The MRS acquisitions were performed using a spin echo sequence at short and long echo times (TE = 30 ms and 135 ms) with a VOI located within the cerebral hemisphere at the level of the centrum semiovale. A significant reduction in myo-inositol and choline and an increase in N-acetylaspartate were observed with progressive age. The normal MR spectroscopy data reported here will help to determine whether brain metabolism is altered, especially when subtle anatomic changes are observed on conventional images. Some examples of impaired fetal brain ...
2006-02-01
International Nuclear Information System (INIS)
Microsecond pulse radiolysis of oxygenated aqueous solutions containing 0.02 mol dm"-"3 sodium formate and 2 mmol dm"-"3 phosphate buffer at pH 7 was used to generate superoxide anion radicals. The influence of some biologically important compounds upon the rate of O_2"."-"b"a"r decay as monitored spectrophotometrically in the range of 245-300 nm. Hematoporphyrin (HP), hemin C (HC), catalase (Cat), cobalt sulfophthalocyanine (CoTSPc) were studied. Among the investigated compounds only Cat was found to show a high catalytic efficiency towards the self-decay of O_2"."-"b"a"r. A red shift of 0_2"."-"b"a"r absorption band and slowing down of its decay were observed to take place by adding HP or CoTSPc to the solutions containing formate ions in excess. This effect is associated with the formation of a transient superoxo-complex. An appearance of an intermediate species with absorption maxima at 350 nm and half-life of about 2 s was ...
Is X(1812) a $(K^*\\bar K^*)$ Molecular State?
We investigate the possibility of producing the $\\omega\\phi$ threshold enhancement recently observed in the $J\\psi\\to\\gamma X(1812),~X(1812)\\to\\omega\\phi$ at BES by assuming the X(1812) to be a candidate of $(K^{*}\\bar K^{*0})$ molecular state. We evaluate the decay rate of $X(1812)\\to\\eta\\eta', \\eta\\eta, \\omega\\phi, K^+K^-, \\rho^+\\rho^-$, $\\omega\\omega, K^{*+}K^{*-}$ and $\\pi^+\\pi^-$ based on the X(1812) to be a candidate of $(\\ksks)$ molecule. It turns out the X(1812) dominantly decays into $\\eta\\eta'$ and $\\eta\\eta$. These channels are suggested to be the laboratory to test the molecular scenario in experiment. We also evaluate the branching fraction $Br(X\\to\\omega\\phi)\\simeq 4.60%$. However, the X(1812) has small branching fractions to decay into other $VV$ or $PP$ final states, from which it seems to be consistent with the experimental observation. In the molecular scenario, the X(1812) ...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
A Real-Time Neutron Radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a CANDU-type 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the CANDU-type rod bundles. A new flow regime is observed and designated Large Amplitude Stratified Wavy flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occurring in the bundle. The rods in the bundle may act as a dampener to the vertical flow and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential direction. The effect of ...
1997-12-31
Energy Technology Data Exchange (ETDEWEB)
A real-time neutron radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a cylindrical 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the cylindrical rod bundles. A new flow regime is observed and designated large amplitude stratified wavy (LASW) flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occuring in the bundle. The rods in the bundle may act as a dampener to the vertical flow component and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential ...
2000-08-01
International Nuclear Information System (INIS)
A Real-Time Neutron Radiography (RTNR) system is used to determine two-phase flow parameters for a horizontal co-current two-phase flow channel with a CANDU-type 37 rod bundle. Image processing techniques are applied to visualize the two-phase flow, and to determine flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution. The experimentally determined flow regime map disagrees with existing flow regime models developed for the CANDU-type rod bundles. A new flow regime is observed and designated Large Amplitude Stratified Wavy flow. The results show that the LASW flow regime may be due to a combination of undeveloped flow phenomena, boundary conditions, and circumferential cross flow occurring in the bundle. The rods in the bundle may act as a dampener to the vertical flow and hinders the development of the wave into plug or slug flow by changing the momentum of the fluid in the circumferential direction. The effect of ...
1997-10-04
Images of very high energy cosmic ray sources in the Galaxy: I. A source towards the galactic centre
Energy Technology Data Exchange (ETDEWEB)
Recent analyses of the anisotropy of cosmic rays at 10{sup 18} eV (the AGASA and SUGAR data) show significant excesses from regions close to the galactic centre and Cygnus. Our aim is to check whether such anisotropies can be caused by single sources of charged particles. We investigate propagation of protons in two models of the galactic regular magnetic field (with the irregular component included) assuming that the particles are injected by a short-lived discrete source lying in the direction of the galactic centre. We show that apart from a prompt image of the source, the regular magnetic field may cause delayed images at quite large angular distances from the actual source direction. The image is strongly dependent on the time elapsed after ejection of particles and it is also very sensitive to their energy. For the most favourable conditions for particle acceleration by a young pulsar, the predicted fluxes are two to four orders of magnitude higher than those ...
2002-08-01
IR double-resonance spectroscopy applied to the 4-aminophenol(H{sub 2}O){sub 1} cluster
Energy Technology Data Exchange (ETDEWEB)
The IR double-resonance techniques IR/R2PI (infrared/resonant 2-photon ionization), IR/PIRI (infrared-photo-induced Rydberg ionization) and IR-photodissociation spectroscopy are valuable tools to investigate structure, vibrations, and dynamical processes of neutral and ionic hydrogen-bonded clusters containing aromatic molecules. In this paper we report on the application of the IR double-resonance techniques to determine the NH and OH stretching vibrations of 4-aminophenol and 4-aminophenol(H{sub 2}O){sub 1}, both in the neutral (S{sub 0}) and ionic (D{sub 0}) ground state. All vibrational frequencies obtained for 4-aminophenol and the cluster are compared with the values obtained from ab initio and DFT calculations. In the S{sub 0} state, a trans-linear arrangement of 4-aminophenol(H{sub 2}O){sub 1} is obtained containing an O-H. O hydrogen bond. In the D{sub 0} state an overlay of two spectra can be observed resulting from the trans-linear ...
2001-03-01
Heat transfer and hydraulics of liquid metal-gas two-phase magnetohydrodynamic flow
International Nuclear Information System (INIS)
Local properties and heat transfer have been investigated in a NaK-nitrogen two-phase flow in a vertical tube under transverse magnetic field. An objective two-phase flow regime identification was also carried out systematically, using the probability distribution function of two-phase electromagnetic flowmeter signals. The application of a magnetic field was bound to bring about a drastic change in the void fraction profile, i.e., asymmetric profile perpendicular to the field direction. This effect was more remarkably observed in bubbly flows. The magnetic field was also observed to decrease the number of bubbles, by promoting the agglomeration of small bubbles into larger ones and also break-up of large slugs, and, thus, to shift the flow regime boundaries. It has been also shown that the two-phase Nusselt number increases in bubbly flows, while it decreases in slug flows. This trend however reduces in the presence of a ...
1986-08-01
Grain boundary transport in x-ray irradiated polycrystalline diamond
International Nuclear Information System (INIS)
The transport properties of a 'thin' polycrystalline diamond film are analyzed after the sample exposure to 8.06-keV x-ray radiation. Structure and morphology of the as-grown film have been evaluated by Raman, x-ray diffraction, and scanning electron microscopy techniques. The transport properties have been investigated by measuring dark current-voltage characteristics in the temperature range of 60 to 360 K. Ohmic transport has been evidenced on the as-grown film up to 1.16x10"5 V/cm. After irradiation, nonlinear contributions to the dark current have been evidenced and related to field-assisted thermal ionization of traps. Below 200 K, hopping mechanisms have been observed. Correlations have been found among x-ray irradiation, density of traps involved in the transport processes, and the nonhomogeneous nature of the sample. A simple model of the grain boundary structure is proposed to explain the observations.
2003-05-15
Grain boundary mobility in Y{sub 2}O{sub 3}: defect mechanism and dopant effects
Energy Technology Data Exchange (ETDEWEB)
The effects of the dopants, Mg{sup 2+}, Sr{sup 2+}, Sc{sup 3+}, Yb{sup 3+}, Gd{sup 3+}, La{sup 3+}, Ti{sup 4+}, Zr{sup 4+}, Ce{sup 4+}, and Nb{sup 5+}, on the grain boundary mobility of dense Y{sub 2}O{sub 3} have been investigated from 1,500 to 1,650 C. Parabolic grain growth has been observed in all cases over a grain size from 0.31 to 12.5 {micro}m. Together with atmospheric effects, the results suggest that interstitial transport is the rate-limiting step for diffusive processes in Y{sub 2}O{sub 3}, which is also the case in CeO{sub 2}. The effect of solute drag cannot be ascertained but the anomalous effect of undersized dopants (Ti and Nb) on diffusion enhancement, previously reported in CeO{sub 2}, is again confirmed. Indications of very large binding energies between aliovalent dopants and oxygen defects are also observed. Overall, the most effective grain growth inhibitor is Zr{sup 4+}, while the most potent grain ...
1996-07-01
Grain boundary mobility in Y_2O_3: defect mechanism and dopant effects
International Nuclear Information System (INIS)
The effects of the dopants, Mg"2"+, Sr"2"+, Sc"3"+, Yb"3"+, Gd"3"+, La"3"+, Ti"4"+, Zr"4"+, Ce"4"+, and Nb"5"+, on the grain boundary mobility of dense Y_2O_3 have been investigated from 1,500 to 1,650 C. Parabolic grain growth has been observed in all cases over a grain size from 0.31 to 12.5 microm. Together with atmospheric effects, the results suggest that interstitial transport is the rate-limiting step for diffusive processes in Y_2O_3, which is also the case in CeO_2. The effect of solute drag cannot be ascertained but the anomalous effect of undersized dopants (Ti and Nb) on diffusion enhancement, previously reported in CeO_2, is again confirmed. Indications of very large binding energies between aliovalent dopants and oxygen defects are also observed. Overall, the most effective grain growth inhibitor is Zr"4"+, while the most potent grain growth promoter is Sr"2"+, both at 1.0% concentration.
Exploring the 2D to 3D dimensionality crossover in thin iron films
Energy Technology Data Exchange (ETDEWEB)
The temperature dependence of the spontaneous magnetization of epitaxial iron films with a thickness ranging from d=20 to 200nm has been measured. The films are grown on GaAs (100) substrates which are covered by a 150nm thick silver (100) buffer layer. For three-dimensional BCC iron it was observed already in 1929 that saturation of the spontaneous magnetization for T->0 is perfectly described by a T{sup 2} power law. On the other hand, for thin two-dimensional (2D) iron films a T{sup 3/2} law has been established in many recent experimental investigations. In our iron films grown on diamagnetic silver, this dimensionality change occurs at a thickness between d=100 and 200nm. Comparison of the here-observed T{sup 3/2} coefficients with those on iron films grown on paramagnetic tungsten (110) shows that the 2D interactions are {approx}20 times larger in the films on tungsten. Recent results on Fe films which are ...
2006-05-15
Energy Technology Data Exchange (ETDEWEB)
The coherent interaction of femtosecond laser pulses and a thin CdSe sample is investigated both experimentally and theoretically. Observation of coherent phenomena in semiconductors is very rare because the incoherent processes occur in the femtosecond time domain in these materials. One example of such a phenomena is the so called optical Stark effect of exciton where a blue shift of the exciton resonance occurs as a result of pumping below the bandgap. The coherent effects involving band-to-band and also exciton transitions. Using femtosecond transmission measurements clear evidence was observed for coherent interference effects of the light field and the driven material polarization. These interferences manifest themselves as oscillatory structures in the differential transmission spectra. The oscillatory features are explained by comparison with a semiclassical theory. Examples of the computed results are presented for ...
1987-01-01
Energy Technology Data Exchange (ETDEWEB)
Water and mud samples were collected from canals and rivers which were adjacent to outlets discharging warm water of 3 power plants in Berlin. Downstream samples from 1 bathing resort were also collected. Free living amoebae were isolated from 138 water and 69 mud samples. From these respectively 156 and 73 strains could be cultured and were administered intranasally to mice for pathogenicity tests. Two Acanthamoeba strains from water and 7 from mud could be reisolated from mouse brain and or lungs, although no pathological disorders could be observed. Five Naegleria strains were negative in mouse inoculation tests. Four Acanthamoeba strains which were positive in mice were cultured at + 45 degrees C; no cytopathogenic effects were observed in tissue cultures. Acanthamoeba infective for mice could also be isolated from samples at low water temperatures. Further investigations have to show, whether changes in virulence of ...
1982-05-01
The purpose of this study was to prepare recombinant human epidermal growth factor (rhEGF) collagen sponges for topical applications and investigate the effects of different types of crosslinked collagen sponges as platforms for the controlled release of rhEGF. The microstructure and the drug release rates of collagen sponges were modified through treatment with different types (glutaraldehyde (GTA), genipin and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)), different concentrations of crosslinking agents and various preparation conditions. A controlled release profile was observed for the crosslinked collagen sponges as compared to the non-crosslinked ones. The results indicated that the GTA crosslinked sponges have the most potent controlling effect. As the amount of GTA increased, a greater rigidity of the collagen sponge structure combined with a lower hydrophilicity was observed, leading to a decreased drug ...
2007-10-04
International Nuclear Information System (INIS)
Nitrogen doped Diamond-like carbon thin films were deposited on n-Si and SiO_2 substrates by rf magnetron sputtering using pure graphite (99.999%) as the target material and mixtures of Ar, N_2 and H_2 for plasma generation. The dependence of structural and optical properties on nitrogen content was investigated using XPS, Raman spectroscopy, FT-IR spectroscopy, and Ellipsometry studies. It was found that as the nitrogen content was increased in the plasma, sp"2 bonding favored. Also it was observed that oxygen contamination increased with nitrogen content. Typical C-H stretching modes connected with diamond-like carbon could be seen in FT-IR spectra. The I_D and I_G bands were well defined and it was observed that as nitrogen content increased I_G band was enhanced. Ellipsometry studies revealed that the optical constants like refractive index (n) and extinction co-efficient (k) increased with increase in nitrogen content ...
2003-03-01
International Nuclear Information System (INIS)
The structural, morphological and optical properties of vacuum-evaporated CdTe thin films were investigated as a function of substrate temperature and post-deposition annealing without and with CdCl2/treatment at 400 C for 30 min. Diffraction patterns are almost the same exhibiting higher preferential orientation corresponding to (111) plane of the cubic phase. The intensity of the (111) peak increased with the CdCl2/annealing treatment. The microstructure observed for all films following the CdCl2/annealing treatment are granular, regardless of the as-deposited microstructure. The grain sizes are increased after the CdCl2/annealing treatment but now contain voids around the grain boundaries. The optical band gaps, Eg, were found to be 1.50, 1.50 and 1.48 eV for films deposited at 200 K and annealed without and with CdCl2/treatment at 400 C for 30 min respectively. A progressive sharpening of the absorption edge upon heat treatment particularly ...
2007-09-01
Internal hydrological processes in suburban watersheds and their effects on water quality warrant investigation. Instrument clusters (throughfall collectors, suction lysimeters, monitoring wells, and shallow and deep piezometers) were installed at several locations within three small (50 - 70 ha) watersheds (one forested, two with different degrees of suburban development) in the Croton Watershed, southeastern New York. Biweekly and storm samples were analyzed for base cations, selected anions, and DOC over a one-year period. The topographic index (TI) quantified landscape position; flowpath analyses determined degree of development at each cluster, using % impervious cover as the metric. Water quality degradation was observed in sites with medium and high TI values; no such effect was observed along the ridges, i.e., low TI values. At medium TI values, areas with more than 5% impervious had degraded water quality. At high ...
2003-12-01
Energy Technology Data Exchange (ETDEWEB)
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to ...
1984-09-01
International Nuclear Information System (INIS)
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the reconstructed image. The image quality could be satisfactory to ...
1984-01-01
Charge and CP asymmetries of $B_q$ meson in unparticle physics
Recently the D{\\O} Collaboration reported an observation of like-sign charge asymmetry (CA), which is about $3.2 \\sigma$ deviation from the standard model (SM) prediction. Inspired by the observation we investigate the scalar unparticle effects, under the color charge of $SU(3)_c$ symmetry, in the CP violation in neutral B meson oscillations as well as the dispersive and absorptive parts of $\\bar B_q\\leftrightarrow B_q$ transition, which can be related to the CA directly. In order to illustrate the peculiar properties of unparticle, our analysis is carried out in two scenarios for the right-handed section: (I) $\\lambda_R=\\lambda_L$ and $U_D^R=U_D^L$, where $\\lambda_{L,R}$ and $U_D^{L,R}$ are the couplings and flavor mixing matrix of left- and right-handed section, respectively; (II) $\\lambda_R >> \\lambda_L$ and $U_D^R$ is completely a free parameter. In scenario I we found that the wrong- and like-sign CA ...
2010-01-01
Bullets in a Core Collapse Supernova Remnant The Vela Remnant
We use two-dimensional hydrodynamical simulations to investigate the properties of dense ejecta clumps (bullets) in a core collapse supernova remnant, motivated by the observation of protrusions probably caused by clumps in the Vela supernova remnant. The ejecta, with an inner flat and an outer steep power law density distribution, were assumed to freely expand into an ambient medium with a constant density, $\\sim 0.1$ H atoms cm$^{-3}$ for the case of Vela. At an age of $10^4$ yr, the reverse shock front is expected to have moved back to the center of the remnant. Ejecta clumps with an initial density contrast $\\chi \\sim 100$ relative to their surroundings are found to be rapidly fragmented and decelerated. In order to cause a pronounced protrusion on the blast wave, as observed in the Vela remnant, $\\chi \\sim 1000$ may be required. In this case, the clump should be near the inflection point in the ejecta density ...
2001-01-01
An on-line video image processing system for real-time neutron radiography
International Nuclear Information System (INIS)
The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 ...
1983-09-01
British Library Electronic Table of Contents (United Kingdom)
Summary Background Treatment of localised renal cell carcinoma consists of partial or radical nephrectomy. A substantial proportion of patients are at risk for recurrence because no effective adjuvant therapy exists. We investigated the use of an autologous, tumour-derived heat-shock protein (glycoprotein 96)-peptide complex (HSPPC-96; vitespen) as adjuvant treatment in patients at high risk of recurrence after resection of locally advanced renal cell carcinoma. Methods In this open-label trial, patients were randomly assigned to receive either vitespen (n=409) or observation alone (n=409) after nephrectomy. Randomisation was done in a one to one ratio by a computer-generated pseudo-random number generator, with a block size of four, and was stratified by performance score, lymph node stat...
2008-01-01
Absorption Features in Spectra of Magnetized Neutron Stars
The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50 - 200 eV, whose nature is not yet well known. To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B ~ 10^{14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS\\,1223 and conclude that the observations can be explained by a thin hydrogen atmosphere above ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Radon concentration measurements in atmosphere were taken in years from 1997 to 1999 in Milan and at pre-alpine sites located north of Lombardy. In this paper the results of measuring campaigns and a comparison of radon levels observed in the hilly area north of the town and on the pre-Alps are reported. The general criteria of the measurements and the interpretative models of radon concentration are presented. The Lake Maggiore area shows evidence of a great nocturnal stability and frequent formation of Nocturnal Stable Layer. The peculiar findings in the high altitude stations confirm the use of radon as an indicator of atmospheric dispersion of pollutants in an area with complex orography. The afternoon minimum values are concordant for the different stations: this implies a remixing in afternoon hours over the whole area investigated.
2006-07-01
British Library Electronic Table of Contents (United Kingdom)
Recent studies have shown Y chromosome microdeletions associated with male infertility. The factors responsible for Y chromosome microdeletions in spermatozoa remain unresolved. However, the environmental pollutants are known to damage DNA in differentiating and maturing germ cells in the male reproductive tract. Therefore, the aim of this study was to investigate the effects of seminal hexachlorocyclohexane (HCH) and its isomers, an environmental pollutant, in 50 fertile and 50 infertile males in relation to semen quality and the incidence of Y chromosome microdeletion in azoospermic factor (AZF) region. As compared to control, an increased HCH level and significantly decreased semen quality were observed in the infertile males. A positive significant association was found between sperm c...
2010-01-01
Wave formation mechanism in magnetic pulse welding
British Library Electronic Table of Contents (United Kingdom)
Wavy interface morphology is observed in Magnetic Pulse Welding (MPW) similarly to that of the Explosion Welding process (EXW). It is recognized that interfacial waves are formed in a periodic manner and have well defined wavelength and amplitude. The phenomenon of wave formation in EXW has been subjected to extensive investigations in which empirical and numerical models have been published. In the present study, a wave formation mechanism for MPW is presented. This wave-creation mechanism was studied by evaluating the influence of sample geometry on wave morphology using stereoscopic optical microscopy. It was found that interfacial waves are formed in a Kelvin-Helmholtz instability mechanism. Reflected shock waves interact with the welding collision point at the weld interface, where in...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
Water-resources data for the 1991 water year for Minnesota consist of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. The volume contains discharge records for 60 gaging stations; stage and contents for 9 lakes and reservoirs; water quality for 18 stream stations, 1 lake station, 22 partial-record sites, 1 precipitation station, 108 wells; and water levels for 119 observation wells. Also included are 59 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are published as miscellaneous measurements or low-flow investigations.
1992-09-01
Varying-G Cosmology with Type Ia Supernovae
The observation that Type Ia supernovae are fainter than expected given their red shifts has led to the conclusion that the expansion of the universe is accelerating. The widely accepted hypothesis is that this acceleration is caused by a cosmological constant or, more generally, some dark energy field that pervades the universe. This hypothesis presents a challenge to physics so severe that one is motivated to explore alternative explanations. In this paper, we explore whether the data from Type Ia supernovae can be explained with an idea that is almost as old as that of the cosmological constant, namely, that the strength of gravity varies on a cosmic timescale. This topic is an ideal one for investigation by an undergraduate physics major because the entire chain of reasoning from models to data analysis is well within the mathematical and conceptual sophistication of a motivated undergraduate.
2009-01-01
Total cross sections of ultracold neutron interactions with some gases
Energy Technology Data Exchange (ETDEWEB)
Measurement results of total interaction cross sections averaged by the spectrum of ultracold neutrons (UCN) within the rate range from 3.2 to 5.7 m/s at the temperatures of 80 and 300 K for the following gases: hydrogen, parahydrogen, helium-4, nitrogen, neon, argon, xenon are presented. The experiment has been conducted conducted in the facility for UCN extraction, mounted in the radial channel of the WWR-K reactor. Experimental dependences of UCN counting rate on pressure of the investigated gases in the chamber varying from 0 to 1.5x10/sup 3/ torr are presented graphically. The measured total cross sections mainly satisfactorily agree with calculations, divergences are observed only for hydrogen and xenon.
1981-11-01
Energy Technology Data Exchange (ETDEWEB)
Generation of anomalous resistivity and dynamical development of collisionless reconnection in the vicinity of a magnetically neutral sheet are investigated by means of a three-dimensional particle simulation. For no external driving source, two different types of plasma instabilities are excited in the current layer. The lower hybrid drift instability (LHDI) is observed to grow in the periphery of current layer in an early period, while a drift kink instability (DKI) is triggered at the neutral sheet in a late period as a result of the nonlinear deformation of the current sheet by the LHDI. A reconnection electric field grows at the neutral sheet in accordance with the excitation of the DKI. When an external driving field exists, the convective electric field penetrates into the current layer through the particle kinetic effect and collisionless reconnection is triggered by the convective electric field earlier than the DKI is excited. It is ...
1999-06-01
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,{tau}) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe{sup 8+}. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe{sup 8+} transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
International Nuclear Information System (INIS)
Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,?) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe8+. The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe8+ transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)
2004-11-30
The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure.
We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p?=?0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+-) genotypes were associated with a decrease in urine naphthalene level (p?0.0001). The NKA show great promise as biomarkers for dermal exposure to naphthalene. Further studies are warranted to characterize the relationship between NKA, other exposure biomarkers, and/or biomarkers of biological effects due to naphthalene and/or PAH exposure. PMID:21961652
2011-09-30
The response of small scale rigid targets to shallow buried explosive detonations
British Library Electronic Table of Contents (United Kingdom)
Experimental and computational investigations were performed in order to better understand the mechanical response of rigid targets with various geometries to the detonation of shallow buried explosives. The motion of the targets was measured by use of high-speed digital video photography. This work involved flat targets, targets that were downwardly convex, and targets that were downwardly concave with explosive charges located at various positions beneath the targets. It was observed that, in general, angled hulls - whether downwardly concave or convex - tended to reduce the amount of momentum imparted to the center of mass of the targets. Computations were performed by use of an arbitrary Langrangian-Eulerian treatment in a nonlinear finite element code. A model based on quasi-static te...
2011-01-01
The geometry emerging from the symmetries of a quantum system
We investigate the relation between the symmetries of a quantum system and its topological quantum numbers, in a general C*-algebraic framework. We prove that, under suitable assumptions on the symmetry algebra, there exists a generalization of the Bloch-Floquet transform which induces a direct-integral decomposition of the algebra of observables. Such generalized transform selects uniquely the set of "continuous sections" in the direct integral, thus yielding a Hilbert bundle. The emerging geometric structure provides some topological invariants of the quantum system. Two running examples provide an Ariadne's thread through the paper. For the sake of completeness, we review two related theorems by von Neumann and Maurin and compare them with our result.
2009-01-01
The effect of excimer laser pretreatment on diffusion and activation of boron implanted in silicon
International Nuclear Information System (INIS)
We have investigated the effect of excimer laser annealing (ELA) on transient enhanced diffusion (TED) and activation of boron implanted in Si during subsequent rapid thermal annealing (RTA). It is observed that ELA with partial melting of the implanted region causes reduction of TED in the region that remains solid during ELA, where the diffusion length of boron is reduced by a factor of #approx#4 as compared to the as-implanted sample. This is attributed to several mechanisms such as liquid-state annealing of a fraction of the implantation induced defects, introduction of excess vacancies during ELA, and solid-state annealing of the defects beyond the maximum melting depth by the heat wave propagating into the Si wafer. The ELA pretreatment provides a substantially improved electrical activation of boron during subsequent RTA.
2005-11-07
The dark matter halos of Draco and Ursa Minor
International Nuclear Information System (INIS)
Published density profiles and central velocity dispersions place important constraints on the stellar velocity ellipsoid and on the distribution of dark matter (DM) in the dwarf spheroidal galaxies Draco and Ursa Minor. Central velocity dispersions of 9 km/s are adopted for Draco and 11 km/s for Ursa Minor. Then, for an isotropic stellar velocity distribution, the central DM densities are 0.8 and 1.0 solar mass/cu pc, respectively, if visible and dark matter have the same core radius. If DM has a much larger core radius than visible matter but nevertheless dominates the potential, these densities are reduced by a factor of 2. Central DM densities can be lower than this only if the stellar velocity distribution is anisotropic. Simple two-component King models are used to investigate this and to look for the smallest DM densities that are consistent with the observations. 36 refs.
The Use of Weighting in Periodicity Searches in All-Sky Monitor Data: Applications to the GLAST LAT
Energy Technology Data Exchange (ETDEWEB)
The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of {gamma}-ray binaries.
2009-06-25
Tantalum nitride as a diffusion barrier between Pd/sub 2/Si or CoSi/sub 2/ and aluminum
Energy Technology Data Exchange (ETDEWEB)
Reactively sputtered tantalum nitride (Ta/sub 2/N) has been investigated as a diffusion barrier between Pd/sub 2/Si and aluminum and CoSi/sub 2/ and Al. Ta/sub 2/N is found to be an excellent matallurgical diffusion barrier for the two systems up to 555 /sup 0/C, with no intermixing observed in Rutherford backscattering and Auger electron spectroscopic studies. Schottky barrier devices n-Si/Pd/sub 2/Si/Ta/sub 2/N/Al were excellent and showed no deterioration after annealing at 500 /sup 0/C. However, similar devices with CoSi/sub 2/ contacts and Ta/sub 2/N barrier showed a creation of high contact resistance between the silicide and the as-deposited nitride.
1989-04-15
A phase 2 study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This report covers the second quarter of work. The major accomplishments were: completion of coal liquefaction autoclave reactor runs with Illinois number 6 coal at processing temperatures of 300, 325, and 350 C, and pressures of 1800 psig; analysis of the filter cake and the filtrate obtained from the treated slurry in each run; and correlation of the coal conversions and the liquid yield quality to the surfactant concentration. An increase in coal conversions and upgrading of the liquid product quality due to surfactant addition was observed for all runs.
1993-03-01
Energy Technology Data Exchange (ETDEWEB)
The effect of {ital in} {ital situ} photoexcitation during boron ion implantation on subsequent transient enhanced B diffusion in Si has been investigated. Photoexcitation using a mercury arc lamp was performed during B{sup +} implantation at 35 keV for a dose of 5{times}10{sup 14} cm{sup {minus}2} at 177 K. A reduction in the electrical activation dip, i.e., reverse annealing effect, in the temperature range 550--700 {degree}C was observed. Also, the transient enhanced diffusion of B, measured using SIMS following 800 {degree}C, 30 min annealing, was suppressed. Both effects demonstrate that the creation of self-interstitials during the implantation process is significantly reduced. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
1995-10-09
International Nuclear Information System (INIS)
The effect of in situ photoexcitation during boron ion implantation on subsequent transient enhanced B diffusion in Si has been investigated. Photoexcitation using a mercury arc lamp was performed during B"+ implantation at 35 keV for a dose of 5x10"1"4 cm"-"2 at 177 K. A reduction in the electrical activation dip, i.e., reverse annealing effect, in the temperature range 550--700 degree C was observed. Also, the transient enhanced diffusion of B, measured using SIMS following 800 degree C, 30 min annealing, was suppressed. Both effects demonstrate that the creation of self-interstitials during the implantation process is significantly reduced. copyright 1995 American Institute of Physics.
Substitution of neodymium in the Formula Not Shown superconductor
British Library Electronic Table of Contents (United Kingdom)
The Fe-based copper oxide Formula Not Shown exhibits superconductivity around 50K only when it is properly annealed in Formula Not Shown atmosphere and subsequently in Formula Not Shown atmosphere. In contract Formula Not Shown does not exhibit superconductivity even if it is annealed along the same process as Formula Not Shown . We have synthesized the polycrystalline samples of Formula Not Shown solid solution system Formula Not Shown to investigate the Nd substitution effects. DC magnetization measurements have shown that, the samples in a range of Formula Not Shown exhibit superconductivity and Formula Not Shown was reduced with increasing the Nd content. However, we could not observe the superconductivity for Formula Not Shown and 1. Rietveld refinement results revealed that due to th...
2008-01-01
Split anterior tibial tendon transfer for varus equinus spastic foot deformity
British Library Electronic Table of Contents (United Kingdom)
Spastic equinovarus foot deformity commonly occurs after stroke or head trauma. Management by split anterior tibial tendon transfer to the lateral border of the foot was chosen by the authors. The purpose of that work was to assess the reliability of this method to improve patient's functional autonomy and investigate the relationship between the initial clinical examination findings and the quality of the functional results. 84 feet, operated in 82 patients out of 130, of mean age 46 years, were reviewed at a mean follow-up of 65 months. Very few complications were observed. Toe deformities remain a commonly associated problem. 80 patients were able to walk barefoot, 74 reported an increase in their walking distance, and 73 could regularly wear normal shoes. There is a strong relationship...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Summary 1. In the Greater Yellowstone Ecosystem, bison Bison bison and elk Cervus canadensis nelsoni act as hosts for Brucella abortus. The presence of B. abortus within wildlife populations is an important conservation issue because of the risk of brucellosis transmission from wildlife to cattle. 2. We investigated conditions facilitating contact between bison (40-60% seroprevalence) and elk on a shared winter range in the Madison headwaters area of Yellowstone National Park. We evaluated the effects of snow pack, season, elk and bison population sizes, and wolf Canis lupus predation risk on the degree of spatial overlap between bison and elk from 1991 to 2006. 3. Sixty-eight per cent of 10 093 independent elk observations occurred within the known bison wintering range, 29% occurred with...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
The influence of radiation on the corrosion of the fuel claddings in a Light Water Reactor (LWR) has been the subject of many investigations, and different aspects of the overall phenomena have been studied by different techniques. Analysis of the evolution of Secondary-Phase Particles (SPPs) for different periods of immersion of the cladding in the reactor enables the rate of corrosion to the structure of the material to be correlated. In the case of Zircaloy-2 in a Boiling Water Reactor (BWR), SPPs are dissolved under irradiation, and their dissolution affects the rate of oxidation and other correlated phenomena. In recent studies, the Zircaloy-2 in claddings loaded in the Leibstadt BWR are analysed after one, three and five cycles. Results are presented, and give an account of the changes which occurred in the materials under irradiation. (authors)
2000-07-01
Energy Technology Data Exchange (ETDEWEB)
The impact of the azimuthal wave refraction in the middle atmosphere on the distribution of gravity wave amplitudes, propagation azimuths, and other wave parameters is investigated using a numerical ray-tracing model of gravity wave propagation through a representative zonal mean reference model of geostrophic winds and temperature in the middle atmosphere. Simulations are first performed with only a single type of gravity wave to help explain some important effects which occur during the refraction process. Then, a multiray simulation is performed which traces a crude spectrum of waves from different altitudes through the atmosphere for every month of a climatological year. The simulated wave climatologies are compared with observations. 108 refs.
1992-10-01
Energy Technology Data Exchange (ETDEWEB)
A number of different theoretical approaches have been used to model to atomic structure and properties of solid-liquid interfaces. Most calculations indicate that ordering occurs in the first several layers of the liquid, adjacent to the crystal surface. In contrast to the numerous theoretical investigations, there have been no direct experimental observations of the atomic structure of a solid-liquid interface for comparison. Saka et al. examined solid-liquid interfaces in In and In-Sb at lattice-fringe resolution in the TEM, but their data do not reveal information about the atomic structure of the liquid phase. The purpose of this study is to determine the atomic structure of a solid-liquid interface using a highly viscous supercooled liquid, i.e., a crystal-amorphous interface.
1996-12-31
British Library Electronic Table of Contents (United Kingdom)
Objective: We have conducted a longitudinal observational study in order to evaluate the prevalence and the incidence of depressive and anxious symptoms in women and men seeking infertility treatment and to analyze associated factors or risk factors for these kinds of disorders. Study design: A total of 1000 consecutive couples that visited our center for the first time were asked to join this study. Depressive and anxious symptoms were assessed with self-rating Zung Depression Scale (ZDS) and Zung Anxiety Scale (ZAS) questionnaires. A second assessment was planned at the time of b HCG dosage (or at the moment of cycle suspension). A standard questionnaire was used to investigate socio-demographic information and the psychological aspects of couples undergoing in vitro fertilization (IVF) ...
2011-01-01
Photoluminescence Decay of Irradiated Herbs
Energy Technology Data Exchange (ETDEWEB)
Thermoluminescence of inorganic dust extract from herbs and spices has been demonstrated to be a useful method to discriminate irradiated food products as well as to estimate the total dose exposure. The time evolution of infrared stimulated luminescence has been systematically investigated in potassium feldspar and albite minerals subjected to different doses of gamma irradiation (ranging from 0 to 8 kGy). Experimental results reveal a 300-600 nm signal which is greatly intensified for irradiated samples, following the same irradiation dose dependence observed in thermoluminescence. The luminescence intensity disappears after few seconds of illumination, following a time evolution which is proportional to (1 + Bt){sup -P}. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)
1999-07-01
Photoluminescence Decay of Irradiated Herbs
International Nuclear Information System (INIS)
Thermoluminescence of inorganic dust extract from herbs and spices has been demonstrated to be a useful method to discriminate irradiated food products as well as to estimate the total dose exposure. The time evolution of infrared stimulated luminescence has been systematically investigated in potassium feldspar and albite minerals subjected to different doses of gamma irradiation (ranging from 0 to 8 kGy). Experimental results reveal a 300-600 nm signal which is greatly intensified for irradiated samples, following the same irradiation dose dependence observed in thermoluminescence. The luminescence intensity disappears after few seconds of illumination, following a time evolution which is proportional to (1 + Bt)"-"P. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)
1998-07-05
Phenomenological dynamics of loop quantum cosmology in Kantowski-Sachs spacetime
The full theory and the semiclassical description of loop quantum cosmology (LQC) have been studied in the Friedmann-Robertson-Walker and Bianchi I models. As an extension to include both anisotropy and intrinsic curvature, this paper investigates the cosmological model of Kantowski-Sachs spacetime with a free massless scalar field at the level of phenomenological dynamics with the LQC discreteness corrections. The LQC corrections are implemented in two different improved quantization schemes. In both schemes, the big bang and big crunch singularities of the classical solution are resolved and replaced by the big bounces when the area or volume scale factor approaches the critical values in the Planck regime measured by the reference of the scalar field momentum. Symmetries of scaling are also noted and suggest that the fundamental spatial scale (area gap) may give rise to a temporal scale. The bouncing scenarios are in an analogous fashion of the Bianchi I model, ...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Phase-separation dynamics are investigated by SALS in aqueous MC solutions in the presence of 5% NaCl, promoted by a quench temperature. The observed scattering peak indicates that the phase separation occurs by the SD mechanism, leading to a bicontinuous structure. A semilog plot of I(q) against time in the early stage of SD gives a straight line, but the position of qmax varies; also, a Cahn-Hilliard plot indicates that diffusive processes dominate and the data can be described by linear CHC theory. Dapp shows a kinetic dependency on the quench temperature. The spinodal temperature of the sample is 41-C. In the late stages, S(q,t) collapses into a universally time-independent curve.
2011-01-01
PKH26 as a fluorescent label for live human umbilical mesenchymal stem cells
British Library Electronic Table of Contents (United Kingdom)
To determine whether PKH26 labeling affects the morphologies, phenotypes, proliferation, and secretion abilities of human umbilical mesenchymal stromal cells (HUMSCs) were investigated. Isolated HUMSCs were labeled with PKH26, and cell morphology was observed under microscope. Cell cycle, apoptotic cell death, expression of PKH26, and the proliferation rate were evaluated. Additionally, fluorescence intensity of PKH26 labeling at different passage times was quantified. There were no detectable differences in cell morphology, cell growth, and proliferation rate after PKH26 labeling. In addition, fluorescence intensity of PKH26 labeling was gradually reduced with increase of the passage times. The PKH26 labeling disappeared after passage six times. In summary, PKH26 labeling is a safe and ef...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Hypertension is one of the most important modifiable risk factors for cardiovascular and cerebrovascular diseases. We investigated the potential antihypertensive effect of the purple passion fruit peel (PFP) extract, a mixture of bioflavonoids, phenolic acids, and anthocyanins, in spontaneously hypertensive rats and human. A high-performance liquid chromatography analysis was performed to identify the active ingredients of the PFP extract. In a rat liver toxicity assay, no hepatotoxicity was observed after 9 hours incubation in the presence of PFP extract (20 ?g/mL). The PFP extract also revealed hepatoprotection against chloroform (1 mmol/L)-induced liver injury. In the experimental model, 24 spontaneously hypertensive rats were divided into 3 treatment groups for a period of 8weeks: cont...
2007-01-01
British Library Electronic Table of Contents (United Kingdom)
The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers' fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to...
2008-01-01
Ocean teleconnections between Antarctica and the Equatorial Pacific and Atlantic.
Environmental Research Database
Objectives(i) Investigate the correlation between Antarctic sea-ice and equatorial sea-surface temperature anomalies in a realistically forced ocean model simulation of the last 50 years. (ii) Determine whether and how the enormous seasonal change in distribution of sea-ice modifies the seasonal cycle at the Equator. (iii) Determine the detailed pathways of wave propagation both in a historically-forced simulation and in response to realistic perturbations. (iv) Quantify the amplitude of the response i [continued...]DescriptionIt is well known that the equatorial ocean-atmosphere system plays a key role in global climate events such as the El Nino-Southern Oscillation (ENSO) phenomenon. There is now compelling evidence that changes in the Antarctic can strongly and quickly affect the equatorial ocean and the ENSO cycle. Observations demonstrate statistically significant correlations (teleconnections) between the Antarctic and the Equator with ...
2009-01-31
Neutron star evolution and emission
This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.
1997-08-01
British Library Electronic Table of Contents (United Kingdom)
The occurrence of persistent organochlorine pesticides (OCPs) in breast milk samples collected from mothers from twelve provinces in mainland China was investigated. Dichlorodiphenyltrichloroethanes (DDTs) were the most prevalent agent, followed by HCHs and HCB, whereas levels of chlordane compounds, drins and mirex were lower. The relatively lower DDE/DDT ratio in the Fujian rural area suggested more recent exposure to DDT than in other areas. The mean level of DDTs in breast milk from the southern China was higher than those from northern China (p < 0.05). A positive correlation was observed between concentration of DDTs in human milk and consumption of animal-origin food, suggesting that this parameter could play an important part in influencing OCPs burdens in lactating women. The mean...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ``parting`` region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ``parting`` region of the welds. (orig.).
1995-12-01
International Nuclear Information System (INIS)
AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ''parting'' region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ''parting'' region of the welds. (orig.).
Measurement of the antiproton/proton ratio in the few-TeV energy range with ARGO-YBJ
Cosmic ray antiprotons provide an important probe for the study of cosmic ray propagation in the interstellar space and to investigate the existence of Galactic dark matter. The ARGO-YBJ experiment is observing the Moon shadow with high statistical significance at an energy threshold of a few hundred GeV. Using all the data collected until November 2009, we set two upper limits on the antip/p flux ratio: 5% at an energy of 1.4 TeV and 6% at 5 TeV with a confidence level of 90%. In the few-TeV range the ARGO-YBJ results are the lowest available, useful to constrain models for antiproton production in antimatter domains.
2010-01-01
Magnetic properties of Fe-Co-Mo-Cu-B nanocrystalline ribbons with stressing surfaces
British Library Electronic Table of Contents (United Kingdom)
Magnetic properties of Fe-Co-Mo-Cu-B alloy system with Co up to 26at.% were investigated. After proper thermal treatment, the nanocrystalline grain remains tiny, the density hardly increases, but the room-temperature saturation attains 1.5T mainly due to a high enough Curie temperature. The generally observed slant hysteresis loops point to ribbon surfaces, which stress the ribbon interior and induce a specific magnetoelastic contribution to hard-ribbon-axis magnetic anisotropy even after vacuum annealing. The effect does not come from cobalt but rather from the lack of silicon. Partial removal of the surfaces resulted in a decrease of the loop tilt.
2011-01-01
International Nuclear Information System (INIS)
This study concerns the Souss upstream basin. The objective is to investigate the characteristics of surface water and groundwater, to assess the impact of artificial recharge as reinforcement of the natural replenishment and assess the renewal of groundwater under semi-arid area. Two major water types are observed: (i) surface waters and upstream springs (least mineralized) and (ii) all groundwater samples (prevailing calcium and magnesium bicarbonate water type). Water isotopes show a low evaporation of precipitations during infiltration. Impoverishment in heavy isotopes is the characteristic of mountain rainfalls, or of a climate colder and wetter than present. Carbon-14 activities (34-94 pmc) indicate a long residence time. The artificial recharge is low compared to the reservoir volume, due to which the renewal rate is also low.
2011-07-01
Ion-induced phase formation in metal-silicon systems
International Nuclear Information System (INIS)
By using megaelectronvolt "4He ion backscattering techniques and transmission electron microscopy, the authors have investigated the interactions of ion beams with thin film structures in a number of silicide-forming systems. The mixed layer was found to be an equilibrium compound for near-noble metals and an amorphous phase for refractory metals. Differences in behavior have also been observed in near-noble metal systems. For palladium, the Pd_2Si phase grew with ion dose and remained crystalline up to high dose. For nickel, the compound Ni_2Si was formed initially and became amorphous on prolonged irradiation. All the results indicate the significance of atomic mobility at target temperatures in determining the phase formation and in explaining the sensitivity of the silicides to ion bombardment. (Auth.).
Interactions at the cofired interface of Ag/Pd electrode and lead-based ferroelectrics
Energy Technology Data Exchange (ETDEWEB)
In the present study, element interdiffusions at the cofired interface of 9/1 Ag/Pd electrode and lead magnesium niobate (PMN)-based ferroelectrics were investigated using Auger Electron Spectroscopy (AES). Intense interdiffusions at the interface were observed while Ag and Pd could penetrate into the ceramics for about 1 {mu}m. Ag-doping experiments were carried out to further study the effects of Ag diffusion on electrical properties of the ceramics. The results showed that Ag could be incorporated into solid solution of the ceramics as Ag{sup +}. As a whole, the Curie temperature (Tc) and dielectric constant of the ceramics decreased with Ag addition. However, Ag addition had no obvious effect on the insulation resistivity. The results inferred that Ag{sup +} could substitute for Pb{sup 2+} at A site of ABO{sub 3} lattice, thereby oxygen vacancies were generated.
2003-05-25
Influence of the X-ray radiation on the lifetime of carriers in the p-n junctions of Si and Ge
International Nuclear Information System (INIS)
Lifetime of minority charae carriers in the Si and Ge p-n unctions has been measured by pulse method of conductivity modulation of base. Its dependence on the X-ray radiation dose has been investigated. Dependence of current transmission coefficients on the dose has been measured and their sharp decrease at low doses and the following saturation at high doses have been observed. Linear dependence of lifetime on X-ray radiation dose has been obtained. Resulting from the comparison of regularities of the change of lifetime due to current characteristics, it has been shown that X-ray radiation leads to the formation of the surface defects, influencing the change of current characteristics as well as to stationary structural defects, causing the decrease of lifetime of the charge carriers with the increase of X-ray radiation dose.
International Nuclear Information System (INIS)
The effect of NaCl and Na_2SO_4 treatments on chlorophyll content, rate of "1"4C assimilation and products of photosynthesis in peanut (Arachish hypogaea L.) variety TMV-10 has been investigated. It was observed that chlorophyll content was affected mainly by NaCl, Na_2SO_4 treatment lowered the rate of photosynthetic "1"4CO_2 fixation. The analysis of labelled products revealed that the salts affect the carbon metabolism differently. The radioactivity was found to be accumulated in fractions of sugars and sugarphosphates in the leaves of NaCl treated plants. Na_2SO_4 treatment brought about considerable decline in labelling of sugars and an increase in labelling of amino acids and sugarphosphates. (orig.).
1980-01-01
Influence of Population III stars on cosmic chemical evolution
British Library Electronic Table of Contents (United Kingdom)
ABSTRACT New observations from the Hubble Ultra Deep Field suggest that the star formation rate at Formula Not Shown drops off faster than previously thought. Using a newly determined star formation rate for the normal mode of Population II/I (PopII/I) stars, including this new constraint, we compute the Thomson scattering optical depth and find a result that is marginally consistent with Wilkinson Microwave Anisotropy Probe 5 results. We also reconsider the role of Population III (PopIII) stars in light of cosmological and stellar evolution constraints. While this input may be needed for reionization, we show that it is essential in order to account for cosmic chemical evolution in the early universe. We investigate the consequences of PopIII stars on the local metallicity distribution fu...
2009-01-01
High-field magnetization of CeRh_2Si_2 and CePd_2Si_2
International Nuclear Information System (INIS)
High-field magnetization properties of single crystalline CeRh_2Si_2 and CePd_2Si_2 were investigated. Two-step metamagnetic transition (H_c_1=25.4 T and H_c_2=26.0 T) was observed in the case of CeRh_2Si_2, whereas no anomaly was found in the magnetization process of CePd_2Si_2 up to 28 T. The mean field analysis has shown that CeRh_2Si_2 is quite anisotropic compared to CePd_2Si_2, which results in the sharp contrast between the magnetization processes of the two compounds
1997-08-04
High coercivity in Nd-Fe-Al-Co-B alloys prepared by mechanical milling
Energy Technology Data Exchange (ETDEWEB)
Nd{sub 40}Fe{sub 30}Al{sub 10}Co{sub 15}B{sub 5} alloys were fabricated by high energy ball milling method under various conditions. Microstructure of the alloys was investigated by X-ray diffraction and electron microscopy techniques. Magnetic properties were characterized by hysteresis and thermomagnetic measurements. The high coercive fields up to 2.36 T have been observed on the samples consisting of Nd{sub 2}(Fe,Co,Al){sub 14}B, Nd{sub 6}(Fe,Co,Al){sub 14} and Nd crystallites imbedded in a residual amorphous matrix.
2008-02-15
Helium-assisted cavity formation in ion-irradiated ceramics
International Nuclear Information System (INIS)
Polycrystalline specimens of spinel (MgAl_2O_4) and alumina (Al_2O_3) were irradiated at room temperature and 650deg C with either dual- or triple-ion beams in order to investigate the effects of simultaneous displacement damage and helium implantation on cavity formation. The cavities in alumina were aligned along the direction of the c-axis, with diameters ranging from < 2 to 10 nm. The cavities in spinel were preferentially associated with dislocation loops and were of similar size as the cavities in alumina. Catastrophic amounts of cavitation were observed at the grain boundaries in spinel when the displacement damage level exceeded a critical value (#approx =# 20 dpa) in the presence of a fusion-relevant (#approx =# 60 appm/dpa) helium environment. (orig.).
1989-12-04
Energy Technology Data Exchange (ETDEWEB)
The Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. For purposes of personnel safety, the spark ignitability of the explosives in the form of unconfined dust layers was also studied. The 20-L data show that most of the explosives dusts were capable of sustaining explosions as dust clouds dispersed in air and some dusts were even capable of sustaining explosions when dispersed in nitrogen. The finest sizes of explosives dusts were less reactive than the larger sizes; this is opposite to the particle size effect observed previously for the pure fuel dusts. The data for the explosives dusts were compared to those for pure fuel dusts. 27 refs., 47 figs.
1989-01-01
Growth mechanisms and thermal stability of ion-beam-induced epitaxial Pd/sub 2/Si films
Energy Technology Data Exchange (ETDEWEB)
Growth mechanisms and thermal stability of ion-beam-induced epitaxial Pd/sub 2/Si films are investigated using Rutherford backscattering and channelling techniques. Epitaxial growth of Pd/sub 2/Si films was observed at room temperature by argon ion implantation into as-deposited Pd/Si(111) structures and furnace-annealed Pd/sub 2/Si(polycrystalline)/Pd/sub 2/Si(epitaxial)/Si(111) structures. Some additional experiments to check the growth mechanisms are also presented, in which the implantation energies, substrate orientations and dose rates were changed. Finally, the stability of the ion-beam-induced epitaxial Pd/sub 2/Si films on subsequent furnace annealing is studied.
1982-06-11
Frequency upconversion properties of Ag: TeO2?ZnO nanocomposites codoped with Yb3+ and Tm3+ ions
British Library Electronic Table of Contents (United Kingdom)
Yb3+?Tm3+ codoped tellurite glasses containing silver nanoparticles (NPs) were synthesized and characterized using transmission electron microscopy and optical techniques. The samples? composition and the nucleation of NPs were investigated using electron diffraction and energy dispersive spectroscopy. For the optical experiments, the samples were excited using a diode laser operating at 980?nm, in resonance with the Yb3+ transition 2F7/2?2F5/2. Photoluminescence (PL) bands corresponding to Tm3+ transitions were observed at 480, 650, and 800?nm due to the Yb3+? Tm3+ energy transfer. PL enhancement was achieved by heat-treatment of the samples at 325?C during different time intervals. The growth of the PL bands correlates with the increase of the silver NPs concentration. The relevant mecha...
2011-01-01
Focused ion beam implantation induced site-selective growth of InAs quantum dots
International Nuclear Information System (INIS)
The site-selective growth of InAs quantum dots (QDs) by a combined focused ion beam (FIB) and molecular beam epitaxy (MBE) process has been demonstrated. An array of FIB modified spots on MBE grown GaAs was fabricated. Thereafter, an in situ annealing step followed by InAs deposition was performed. The InAs QDs were preferentially formed in the holes generated by the FIB. The influences of ion dose, annealing parameters, and InAs amount were investigated. With optimized parameters, the authors observe more than 50% single dot occupancy per holes. Photoluminescence spectra confirm the good optical quality of the QDs.
2007-09-17
Epidemic spreading with nonlinear infectivity in weighted scale-free networks
In this paper, we investigate the epidemic spreading for SIR model in weighted scale-free networks with nonlinear infectivity, where the transmission rate in our analytical model is weighted. Concretely, we introduce the infectivity exponent $\\alpha$ and the weight exponent $\\beta$ into the analytical SIR model, then examine the combination effects of $\\alpha$ and $\\beta$ on the epidemic threshold and phase transition. We show that one can adjust the values of $\\alpha$ and $\\beta$ to rebuild the epidemic threshold to a finite value, and it is observed that the steady epidemic prevalence $R$ grows in an exponential form in the early stage, then follows hierarchical dynamics. Furthermore, we find $\\alpha$ is more sensitive than $\\beta$ in the transformation of the epidemic threshold and epidemic prevalence, which might deliver some useful information or new insights in the epidemic spreading and the correlative immunization schemes.
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2prime-bipyridine)ruthenium(II) (Ru(bpy)32+) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)32+-incorporated clay, graphite powder and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)32+ was investigated. It was observed that the ECL of immobilized Ru(bpy)32+ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri-n-propylamine (TPrA) and the detection limit was found to be 20 pM. In addition, the ECL sensor displayed good stability for TPrA detection and long-term storage stability.
2010-01-01
Effects on focused ion beam irradiation on MOS transistors
Energy Technology Data Exchange (ETDEWEB)
The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.
1997-04-01
British Library Electronic Table of Contents (United Kingdom)
Fatigue crack growth tests of three ferrite-pearlite steels with different size and spacing of pearlite particles, which were uniformly distributed in the ferrite matrix, were carried out to investigate the effect of microstructure on fatigue crack growth behavior in the Paris regime. The fatigue crack growth rates for the three materials did not coincide with each other, even when the crack growth curves were arranged by the effective stress intensity factor range. From in situ observations, crack tip stress shielding phenomena, such as interlocking and branching, were found on the crack wake, which enhanced fatigue crack growth resistance. A small size and spacing of pearlite particle seemed to induce small but frequent crack deflections, which resulted in crack closure phenomena. On the...
2010-01-01
Effects of antipsychotics and amphetamine on social behaviors in spontaneously hypertensive rats
British Library Electronic Table of Contents (United Kingdom)
We have recently reported that spontaneously hypertensive rats (SHRs) exhibit a deficit in contextual fear conditioning that is specifically reversed by antipsychotic and potentiated by psychostimulants and other manipulations thought to produce schizophrenia-like states in rodents. Based on these findings, we suggested that this deficit in fear conditioning could be used as an experimental model of emotional processing impairments observed in schizophrenia. This strain has also been suggested as a model by which to study attention deficit/hyperactivity disorder (ADHD). Considering that schizophrenia and ADHD are both characterized by poor social function, this study aimed to investigate possible behavioral deficits of SHRs in a social context. Furthermore, we sought to examine the effects...
2011-01-01
Effect of smartphone aesthetic design on users' emotional reaction: An empirical study
British Library Electronic Table of Contents (United Kingdom)
Purpose - This paper discusses the impact of aesthetic design of smartphones on users' emotional reactions and preferences towards the product. To this end, the paper presents a study that explores emotional reaction of males to varying aesthetic design of the BlackBerry and empirically evaluates their preferences for the BlackBerry in different colours and overlay patterns. The paper then presents the statistical results of the study in an innovative graphical representation. Design/methodology/approach - A quantitative and qualitative research design was used, including three types of data-collection instruments (direct observations, rating scales, and interviews) to investigate if males have a stronger positive emotional reaction for visually treated BlackBerry Pearl devices over the or...
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
The thermal stability and deformability of Mn-Al-C alloys containing 0.6 pct C are investigated experimentally as a function of excess phase content. It is shown that an increase in Mn content from 68.9 to 73.5 pct leads to increased stability of the high-temperature epsilon phase. The enrichment of the system Mn-Al-Cu in Mn and Al above the optimum composition leads to the formation of nonmagnetic excess phases, eta and beta, which reduce the magnetization of the alloy. In addition, a decrease in thermal stability is observed in the alloy with 73.5 pct Mn due to the decomposition of the ferromagnetic phase. 7 references.
1988-01-01
Diffusion of antimony in silicon in the presence of point defects
Energy Technology Data Exchange (ETDEWEB)
We have investigated the diffusion of Sb in Si in the presence of defects injected by high-energy implantation of Si ions at room temperature. MeV ion implantation increases the concentrations of vacancies, which induce transient-enhanced diffusion of Sb deposited in Si. We observed a significant enhancement of Sb diffusion. Secondary ions mass spectroscopy has been performed on the implanted samples before and after annealing. Rutherford-backscattering spectrometry has been used to characterize the high-energy implantation damage. By fitting diffusion profiles to a linear diffusive model, information about atomic scale diffusion of Sb, i.e. the generation rate of mobile state Sb and its mean migration length were extracted.
2007-08-15
Diffusion of antimony in silicon in the presence of point defects
International Nuclear Information System (INIS)
We have investigated the diffusion of Sb in Si in the presence of defects injected by high-energy implantation of Si ions at room temperature. MeV ion implantation increases the concentrations of vacancies, which induce transient-enhanced diffusion of Sb deposited in Si. We observed a significant enhancement of Sb diffusion. Secondary ions mass spectroscopy has been performed on the implanted samples before and after annealing. Rutherford-backscattering spectrometry has been used to characterize the high-energy implantation damage. By fitting diffusion profiles to a linear diffusive model, information about atomic scale diffusion of Sb, i.e. the generation rate of mobile state Sb and its mean migration length were extracted.
2007-08-01
Determination of radon and thoron permeability through some plastics by track technique
Energy Technology Data Exchange (ETDEWEB)
Experiments have been performed to study the usefulness of several types of plastic foils as filter to separate radon and thoron. Time-integrated alpha-activity measurements have been carried out by using the so-called ''can-technique'' equipped with both LR-115 and CR-39 track detectors. The track density observed on the detectors, taken as a measure of radon activity concentration, has been determined as a function of the thickness of filter foils. The radon permeability and the thoron separation factors have been determined. It is shown that various plastic foils exhibit considerable differences in radon diffusion coefficient owing to their different chemical structures. Among the plastic foils investigated the polyethylene proved to have the highest gas diffusion coefficient.
1986-01-01
Depth dependence of {l_brace}311{r_brace} defect dissolution
Energy Technology Data Exchange (ETDEWEB)
A deep band of {l_brace}311{r_brace} defects was created 520 nm below the silicon surface with a 350 keV Si implant followed by a cluster-forming rapid thermal anneal (800 C, 1000 s). Chemical etching was used to vary the depth to the surface of the {l_brace}311{r_brace}-defect band. Afterwards, the defect dissolution was investigated at 750 C for different times. Varying the depth in this fashion assures that only the depth and no other feature of the cluster distribution is changed. The {l_brace}311{r_brace} defects were analyzed by plan-view, transmission electron microscopy. We show that the dissolution time of the {l_brace}311{r_brace}-defect band varies linearly with depth, confirming that surface recombination controls the dissolution and is consistent with analogous observations of transient enhanced diffusion.
2001-09-03
Depth dependence of #left brace#311#right brace# defect dissolution
International Nuclear Information System (INIS)
A deep band of #left brace#311#right brace# defects was created 520 nm below the silicon surface with a 350 keV Si implant followed by a cluster-forming rapid thermal anneal (800 C, 1000 s). Chemical etching was used to vary the depth to the surface of the #left brace#311#right brace#-defect band. Afterwards, the defect dissolution was investigated at 750 C for different times. Varying the depth in this fashion assures that only the depth and no other feature of the cluster distribution is changed. The #left brace#311#right brace# defects were analyzed by plan-view, transmission electron microscopy. We show that the dissolution time of the #left brace#311#right brace#-defect band varies linearly with depth, confirming that surface recombination controls the dissolution and is consistent with analogous observations of transient enhanced diffusion.
2001-09-03
Dense and diffuse gas in dynamically active clouds
We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should strongly determine the level of background molecular enhancement. We also convolve the ...
2006-01-01
Changes in DNA content during rhizobial nodule development in Lupinus luteus L. 1
International Nuclear Information System (INIS)
Cytophotometric measurements of DNA content after Feulgen's reaction and autoradiography after incubation with "3H-thymidine were performed to investigate the early stages of development of yellow lupin root nodule. The first response of the host plant to the contact with Rhizobium lupini was the enhancement of nuclear DNA endoreplication in root cortex cells. A conversion of the initially mixoploid nodule meristem into a diploid one during root nodule formation was found. Differentiation of bacteroid-containing tissue both from diploid and polyploid cells was observed. The highest content of nuclear DNA in the uninfected root cortex, nodule cortex and in bacteroid-containing tissue was 16 C. (author).
1989-01-01
British Library Electronic Table of Contents (United Kingdom)
In the present study, we report the occurrence of Lyme's borreliosis in patients from the Brazilian Amazon Region. Borreliosis was investigated by immunohistochemistry and focus floating microscopy for Borrelia burgdorferi in skin biopsy samples from 22 patients with both clinical and histopathology evidences compatible with Erythema Migrans. Spirochetes were detected by specific immunohistochemistry and focus floating microscopy for B. burgdorferi in samples from five patients. Clinical cure of the cutaneous lesions was observed in all the patients after treatment with doxycycline regimen as proposed by the Center Disease Control guidelines. A limitation of our study was the fact that we were not able to isolate and culture these organisms. These are the first known Brazilian cases of bor...
2010-01-01
Asymmetric Hydrogenation with Highly Active IndolPhos-Rh Catalysts: Kinetics and Reaction Mechanism
British Library Electronic Table of Contents (United Kingdom)
The mechanism of the IndolPhos-Rh-catalyzed asymmetric hydrogenation of prochiral olefins has been investigated by means of X-ray crystal structure determination, kinetic measurements, high-pressure NMR spectroscopy, and DFT calculations. The mechanistic study indicates that the reaction follows an unsaturate/dihydride mechanism according to Michaelis-Menten kinetics. A large value of KM (KM=5.01+-0.16 M) is obtained, which indicates that the Rh-solvate complex is the catalyst resting state, which has been observed by high-pressure NMR spectroscopy. DFT calculations on the substrate-catalyst complexes, which are undetectable by experimental means, suggest that the major substrate-catalyst complex leads to the product. Such a mechanism is in accordance with previous studies on the mechanism...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15?min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5?...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
In this study we investigated cultural, familial, and individual beliefs that influenced international students? perceptions of therapy and help-seeking behaviors. Included were changes in perception or behavior before and after the students came to the US, and factors that influenced help-seeking behaviors. Six international students from East Asian countries where English is a foreign language, including Taiwan, Mainland China, Japan, and South Korea, were interviewed. We used semi-structured interviews and participant observations for collecting data. The findings indicated changes after students came to the US. Further discussions focus on encouraging and discouraging factors relative to seeing therapists, and culturally sensitive interventions for family therapy clinicians.
2011-01-01
Applicator reconstruction and applicator shifts in 3D MR-based PDR brachytherapy of cervical cancer
British Library Electronic Table of Contents (United Kingdom)
Purpose To evaluate the methods of applicator reconstruction in 3D MR-based planning for brachytherapy of cervical cancer, and to investigate applicator shifts and changes in DVH parameters during PDR treatment. Methods For each application MR scans with applicator in situ were made: three T2-weighted (4.5mm slices) Turbo Spin Echo (TSE) scans and a balanced Steady State Free Precession scan (1.5mm). Three observers tested two applicator reconstruction methods: (A) directly on the bSSFP scan and (B) on a resampled combination of the three T2-weighted scans. For 10 patients MR imaging was repeated on the second day of each PDR fraction to determine applicator shifts and changes in DVH parameters. Results For both applicator reconstruction methods the interobserver variation for the DVH para...
2009-01-01
An assessment of health impacts of electrical power transmission lines
International Nuclear Information System (INIS)
The types of investigations undertaken to test for possible biological effects of extremely low frequency electric fields have been numerous. However, neither animal and plant experimentation nor clinical studies nor experience with operating extremely high voltage transmission lines have to date provided convincing evidence of a harmful effect from exposure to electric fields associated with transmission lines in spite of numerous attempts to find such effects. Analysis of internal fields and currents supports these observations as the levels appear to be too low to affect mammalian cells. Thus, while one can never prove the negative (i.e. that there is no effect), the overwhelming body of evidence indicates that the electric fields associated with high-voltage lines have no deleterious biological effects. (author).
1981-06-26
Aerosol characteristics over coastal regions of the Arabian Sea
Energy Technology Data Exchange (ETDEWEB)
From aerosol spectral optical depths ({tau}{sub p{lambda}}) at wavelengths in the range 380 to 1025 nm estimated at different locations in the near and far coastal regions of the Arabian sea adjoining the western coast of central India, the spatial and spectral characteristics of coastal aerosols and the effect of the proximity to the (urban) continent are investigated. The Aangstroem parameters are deduced from {tau}{sub p{lambda}} values. A significant increase, both in aerosol optical depths at shorter (visible) wavelengths ({lambda} {<=} 600 nm) and the Aangstroem wavelength exponent are observed in the near coastal regions, suggesting an increase in the (relative) concentration of sub micron particles, apparently of anthropogenic origin. The Aangstroem turbidity coefficient remains nearly steady spatially, indicating a (spatially) uniform loading of large particles. 31 refs, 10 figs, 1 tab
1997-09-01
A unified framework for biological evolution and stochastic quantization
We investigate the profound relation between the equations of biological evolution and quantum mechanics by writing a biologically inspired equation for the stochastic dynamics of an ensemble of particles. Interesting behavior is observed which is related to a new type of stochastic quantization. We find that the probability distribution of the ensemble of particles can be decomposed into eigenfunctions associated to a discrete spectrum of eigenvalues. In absence of interactions between the particles, the out-of-equilibrium dynamics asymptotically relaxes towards the fundamental state. This phenomenon can be related with the Fisher theorem in biology. On the contrary, in presence of scattering processes the evolution reaches a steady state in which the distribution of the ensemble of particles is characterized by a Bose-Einstein statistics. In order to show a concrete example of this stochastic quantization we have solved explicitly the case in ...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract One of the most significant problems in industrial bioprocessing of recombinant proteins using engineered mammalian cells is the phenomenon of cell line instability, where a production cell line suffers a loss of specific productivity (qP). This phenomenon occurs with unpredictable kinetics and has been widely observed in Chinese hamster ovary (CHO) cell lines and with all commonly used gene expression systems. The underlying causes (both genetic and physiological) and the precise molecular mechanisms underpinning cell line instability have yet to be fully elucidated, although recombinant gene silencing and loss of recombinant gene copies have been shown to cause qP loss. In this work we have investigated the molecular mechanisms underpinning qP instability over long-term sub-cult...
2011-01-01
A Bayesian approach to analyze energy balance data from lactating dairy cows
British Library Electronic Table of Contents (United Kingdom)
The objective of the present investigation was to develop a Bayesian framework for updating and integrating covariate information into key parameters of metabolizable energy (ME) systems for dairy cows. The study addressed specifically the effects of genetic improvements and feed quality on key parameters in current ME systems. These are net and metabolizable energy for maintenance (NEM and MEM, respectively), efficiency of utilization of ME for milk production (kL) and growth (kG), and efficiency of utilization of body stores for milk production (kT). Data were collated from 38 studies, yielding 701 individual cow observations on milk energy, ME intake, and tissue gain and loss. A function based on a linear relationship between milk energy and ME intake and correcting for tissue energy lo...
2011-01-01
"2"2"2Rn as indicator of atmospheric turbulence: measurements at Lake Maggiore and on the pre-Alps
International Nuclear Information System (INIS)
Radon concentration measurements in atmosphere were taken in years from 1997 to 1999 in Milan and at pre-alpine sites located north of Lombardy. In this paper the results of measuring campaigns and a comparison of radon levels observed in the hilly area north of the town and on the pre-Alps are reported. The general criteria of the measurements and the interpretative models of radon concentration are presented. The Lake Maggiore area shows evidence of a great nocturnal stability and frequent formation of Nocturnal Stable Layer. The peculiar findings in the high altitude stations confirm the use of radon as an indicator of atmospheric dispersion of pollutants in an area with complex orography. The afternoon minimum values are concordant for the different stations: this implies a remixing in afternoon hours over the whole area investigated.
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