Science.gov (United States)

As both computer and mobile phone reach nearly ubiquity in the U.S. market, the slow uptake of mobile video, in contrast to the thriving usage of PC-based video, warrants a deeper understanding of user-oriented factors contributing to the two diffusion paths. Unlike the majority of existing diffusion research practices, the dissertation examines the differences between mobile and PC video diffusion patterns through the lenses of user-oriented influences in the user-technology relationship. Built upon the established adoption user group classification, the research is informed by the Uses and Gratification theory, the Social Technical theory, and the Technical Affordance perspective. These synergistic theoretical arguments share the recognition of the role of user in the dynamic, usually socially intertwined user-technology interactions. The key research questions that the dissertation sets out to answer include: Does the ...

Medline Plus

English - Evacuation and Community Shelters Click to Stop Video Click to Start Video To Listen to the ...

Medline Plus

English - Chemical Emergencies Click to Stop Video Click to Start Video To Listen to the Audio or ...

Energy Technology Data Exchange (ETDEWEB)

The Advanced Networking Integration Department at Sandia National Laboratories has used the annual Supercomputing conference sponsored by the IEEE and ACM for the past three years as a forum to demonstrate and focus communication and networking developments. For Supercomputing `95, Sandia elected: to demonstrate the functionality and capability of an AT&T Globeview 20Gbps Asynchronous Transfer Mode (ATM) switch, which represents the core of Sandia`s corporate network, to build and utilize a three node 622 megabit per second Paragon network, and to extend the DOD`s ACTS ATM Internet from Sandia, New Mexico to the conference`s show floor in San Diego, California, for video demonstrations. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations supports Sandia`s overall strategies in ATM networking.

CERN Document Server

The nucleation and propagation of hydrofractures by injection of over pressured fluids in an elastic and isotropic medium are studied experimentally. Non-Newtonian fluids are injected inside a gelatine whose mechanical properties are assumed isotropic at the experimental strain rates. Linear elastic theory predicts that plastic deformation associated to breakage of gelatin bonds is limited to a small zone ahead of the tip of the propagating fracture and that propagation will be maintained while the fluid pressure exceeds the normal stress to the fracture walls (Ch\\'avez-\\'Alvarez,2008) (i.e., the minimum compressive stress), resulting in a single mode I fracture geometry. However, we observed the propagation of fractures type II and III as well as nucleation of secondary fractures, with oblique to perpendicular trajectories with respect to the initial fracture. In the Video (http://hdl.handle.net/1813/14122) experimental evidence shows that ...

Science.gov (United States)

... Wiki Leaks (The Sunshine Press) Video, 39 min., 2010, electronic video, http://www.collateralmurder.com and http://wikileaks.org/ (accessed 11 ...

National Aeronautics and Space Administration (NASA)

The International Space Station video update for Oct. 19, 2011.

National Aeronautics and Space Administration (NASA)

The International Space Station video update for Oct. 17, 2011.

National Aeronautics and Space Administration (NASA)

The International Space Station video update for Oct. 13, 2011. n

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Nowadays there is a lot of welding processes giving an answer to the great diversity of joints to realize and to the characteristics of the metals employed. The first chapter describes the different power sources used in welding. After that, a more detailed explanation of arc welding is given. Finally we present the design of a welding test bed. One can, of course, use an empirical approach to optimize a process. Nevertheless there are advantages in choosing an analytical approach since we can expect significant progress in the understanding of the dynamical interactions in the arc. That's why we present in the second chapter the theoretical knowledge concerning the behaviour of the molten metal transferred during Gas Metal Arc Welding. This work involves as well an experimental aspect required for the elaboration of the databases used to build the model. The recordings were made at CTAS on a test bed equipped with an acquisition system for measuring voltage, current, wire ...

Science.gov (United States)

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. ...

National Aeronautics and Space Administration (NASA)

The weekly International Space Station video recap for Oct. 10-14, 2011.

Science.gov (United States)

System). From collecting terabytes of video footage to tracking the movements of the submarines, this software is essential to the science team as they explore unique structures on...

Medline Plus

... the nature of DNA testing. 07:56 - President / CEO of a Biotechnology / Pharmaceutical Company - Sherri Bale President ...

Science.gov (United States)

Biochar is fantastic for enriching soil, and you can make it yourself. Screen capture from video of sea ice minimum for 2010. ...

British Library Electronic Table of Contents (United Kingdom)

Between 1986 and 1990 the eruptive activity of Erebus volcano was monitored by a video camera with on-screen time code and recorded on video tape. Corresponding seismic and acoustic signals were recorded from a network of 6 geophones and 2 infrasonic microphones. Two hundred Strombolian explosions and three lava flows which were erupted from 7 vents were captured on video. In December 1986 the Strombolian eruptions ejected bombs and ash. In November 1987 large bubble-bursting Strombolian eruptions were observed. The bubbles burst when the bubble walls thinned to ?20?cm. Explosions with bomb flight-times up to 14.5?s were accompanied by seismic signals with our local size estimate, ?unified magnitudes?? (mu), up to 2.3. Explosions in pools of lava formed by flows in the Inner Crater were co...

Science.gov (United States)

... system size exhibit a stochastic decomposition property ... to manage congestion in the primary queue. ... video at individual computer network terminals. ...

Science.gov (United States)

test bed (ADTT) tools technology. Glenn. Research. Center: Aircraft icing training video for regional and cor- porate pilots. Numerical propulsion ...

Science.gov (United States)

... and (3) the exchange of information; materials or perspectives. In 1977, a conference of ... their peers), to products (e.g., curriculum materials, guidebooks, or videos). We will also take ...

Science.gov (United States)

... s guides and "how-to" videos and other materials, and 7. Receive continuing support from GLOBE's ... and educational materials that result from international proposals in its materials and support ...

International Nuclear Information System (INIS)

A series of real-time, neutron radiography, experiments are ongoing at the Texas A and M Nuclear Science Center Reactor (NSCR). These tests determine the resolving capabilities for radiographic imaging of two phase water and air flow regimes through small diameter flow channels. Though both film and video radiographic imaging is available, the real-time video imaging was selected to capture the dynamic flow patterns with results that continue to improve. (author)

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 ...

Science.gov (United States)

BACKGROUND: : Skills related to cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use by lay responders decay rapidly after training, and efforts are required to maintain competence among trainees. We examined whether repeated viewing of a reminder video on a mobile phone would be an effective means of maintaining CPR and AED skills in lay responders. METHODS: : In a single-blind case-control study, 75 male students received training in CPR and AED use. They were allocated either to the control or to the video-reminded group, who received a memory card containing a video clip about CPR and AED use for their mobile phone, which they were repeatedly encouraged to watch by SMS text message. CPR and AED skills were assessed in scenario format by examiners immediately and 3 months after initial training. RESULTS: : Three months after initial training, the video-reminded group ...

British Library Electronic Table of Contents (United Kingdom)

In this article, self-organizing-map-based video object segmentation is proposed, assuming that either Y-quantification or HSV-quantification can be systematically selected. Given a video sequence, the value of the probability density function for each component value is calculated according to a kernel estimation at the first frame. Some areas randomly chosen from the background are then examined, using each component value, to judge whether or not they include the target object. The quantification is determined so that the frequency of occurrence of false extractions can be reduced. The data presented to the maps are generated based on the selected quantification. Experimental results show that the proposed method recognizes the target object well.

UK PubMed Central (United Kingdom)

Reliable dietary assessment is a challenging yet essential task for determining general health. Existing efforts are manual, require considerable effort, and are prone to underestimation and misrepresentation...Full Text Available

UK PubMed Central (United Kingdom)

This paper describes Image Engine, an object-oriented, microcomputer-based, multimedia database designed to facilitate the storage and retrieval of digitized biomedical still images, video, and text...Full Text Available

Science.gov (United States)

Install. Inspect. Protect. Smoke Alarm Campaign Video 10/28/2009 | 04:09 Cooking_4 Cooking Fire Safety: Watch What You Heat 10/26/2007 | 01:40 Cooking_3 Cooking Fire...

Medline Plus

September 14, 2010 ADHD: Signs, Symptoms, Research NIMH researchers talk about the symptoms of ADHD as well as the latest research. Download this video. Watch on YouTube. Transcript Announcer: ADHD- Attention Deficit Hyperactivity Disorder- is one of the ...

UK PubMed Central (United Kingdom)

A case of severe intractable angina pectoris with normal angiography is presented. Following video assisted thoracic sympathectomy the patient died of heart failure. Microvascular cardiac amyloidosis...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

By means of a global mode analysis of ideal MHD modes for Mercier-unstable equilibria in a planar axis L=2/M=10 heliotron/torsatron system with an inherently large Shafranov shift, the conjecture from local mode analysis for Mercier-unstable equilibria given in [N. Nakajima, Phys. Plasmas 3, 4556 (1996)] has been confirmed and the properties of pressure-driven modes, namely, ballooning modes and interchange modes, inherent to such three-dimensional systems have been clarified. The change of the local magnetic shear due to the Shafranov shift, which is related to toroidicity, reduces the field line bending stabilizing effects on ballooning modes. According to the degree of the reduction of the local magnetic shear by the Shafranov shift, the Mercier-unstable equilibria are categorized into toroidicity-dominant (strong reduction) and ...

Wastenet

... Thursday: South Brisbane Sailing Club, Orleigh Park Hill End Terrace, West End. Friday: Booroodabin Bowls Club, 126 Breakfast Creek Road, Newstead. Related Photos Six months on: Kerrin Quinn's Story (Emma Sykes - ABC Local) Map Fernvale 4306 Subscribe/RSS Subscribe to ABC Brisbane videos Subscribe to all ABC Local videos Topics: disasters-and-accidents, floods Locations: brisbane-4000, fernvale-4306 Print page ...

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CHRONIC HEALTH EFFECTS

Energy Technology Data Exchange (ETDEWEB)

We use the method of Padg approximants and Fourier transform techniques to treat analytically the problem of transverse and longitudinal mode evolution in FELs. We obtain simple relations providing a transparent understanding of the dynamic of pulse propagation effects and of transverse mode guiding. We discuss the interplay with inhomogeneous broadening effects and derive gain formulae including longitudinal and transverse mode couplings.

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Aimed at some typical constraints of police dogs and robots used in the areas of reconnaissance and counterterrorism currently, the multifunction anti-terrorism robotic system based on police dog has been introduced. The system is made up of two parts: portable commanding device and police dog robotic system. The portable commanding device consists of power supply module, microprocessor module, LCD display module, wireless data receiving and dispatching module and commanding module, which implements the remote control to the police dogs and takes real time monitor to the video and images. The police dog robotic system consists of microprocessor module, micro video module, wireless data transmission module, power supply module and offence weapon module, which real time collects and transmits video and image data of the counter-terrorism sites, and gives military attack based on commands. The system combines police dogs" ...

International Nuclear Information System (INIS)

The transverse modes of a submillimetre laser cavity that contains waveguides and open parts were studied theoretically and experimentally with the purpose of finding methods for mode selection. Two methods based on the filtering of the Fourier spectra of the waveguide modes and the use of their interference were substantiated numerically and realised in experiment. Special attention was paid to the mode selection in tunable lasers. Scaling laws allowing one to use the obtained results in a wide range of the cavity parameters and wavelengths are presented. (laser applications and other topics in quantum electronics)

British Library Electronic Table of Contents (United Kingdom)

The piano repertoire preparation of three undergraduate students at three different academic levels - the first, fifth and eighth semesters - was followed during an academic semester. A phenomenological approach was used to collect data in three stages: an introductory interview, observations of the repertoire under preparation and a final observation of the student's recall about his/her study process. In these steps, four complementary research techniques were employed: a semi-structured interview, observation of video recordings of repertoire performances, an unstructured interview about the repertoire under preparation and a recall-stimulated interview in which the student reflected on audio and video recordings of his/her performance. Data were analysed from an Aristotelian perspectiv...

CERN Document Server

Research shows that comment spamming (comments which are unsolicited, unrelated, abusive, hateful, commercial advertisements etc) in online discussion forums has become a common phenomenon in Web 2.0 applications and there is a strong need to counter or combat comment spamming. We present a method to automatically detect comment spammer in YouTube (largest and a popular video sharing website) forums. The proposed technique is based on mining comment activity log of a user and extracting patterns (such as time interval between subsequent comments, presence of exactly same comment across multiple unrelated videos) indicating spam behavior. We perform empirical analysis on data crawled from YouTube and demonstrate that the proposed method is effective for the task of comment spammer detection.

Science.gov (United States)

In this paper, we propose a method based on the Laplacian in the frequency domain for video text detection. Unlike many other approaches which assume that text is horizontally-oriented, our method is able to handle text of arbitrary orientation. The input image is first filtered with Fourier-Laplacian. K-means clustering is then used to identify candidate text regions based on the maximum difference. The skeleton of each connected component helps to separate the different text strings from each other. Finally, text string straightness and edge density are used for false positive elimination. Experimental results show that the proposed method is able to handle graphics text and scene text of both horizontal and nonhorizontal orientation. PMID:20733217

Energy Technology Data Exchange (ETDEWEB)

This report describes the experimental researches on the polarization Characteristics of symmetric GaAs-GaAlAsP double heterojunction lasers, and analyses the mode-competition processes of these lasers. The experiments showed that semiconductor laser is emitted spontaneously and does not indicate optical polarization characteristic when it is biased under the threshold current. When it is biased above the threshold current, the laser for thin active layer of d = 0.15approx.0.40 ..mu..m is generally observed only in fundamental order mode, and TE mode polarization is predominant. At this time, polarization selection is dependent on Fabry-Perot cavity facet (cleaved face) mode reflectivity R/sub 0/. But TM mode is saturated at the threshold, the current applied to the laser above the threshold is used to enhance the TE polarization when the active thickness d is larger than 0.4 ...

UK PubMed Central (United Kingdom)

INTRODUCTIONLevel T4 video-assisted thoracoscopic sympathectomy proved superior to T3-T4 treatment for controlling axillary hyperhidrosis at the initial and six-month follow-ups...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Methods of solving Navier-Stokes equations for turbulent channel flow are given. These numerical solutions utilize either Neumann or Dirichlet boundary conditions. Computer codes were written and tested and are discussed. Digital image processing of flow visualization video sequences, taken simultaneously with vorticity probe measurements in a turbulent boundary layer, were carried out. 4 figs. (GHH)

Energy Technology Data Exchange (ETDEWEB)

The need for a Combustion and Melting Research Facility focused on the solution of glass manufacturing problems common to all segments of the glass industry was given high priority in the earliest version of the Glass Industry Technology Roadmap (Eisenhauer et al., 1997). Visteon Glass Systems and, later, PPG Industries proposed to meet this requirement, in partnership with the DOE/OIT Glass Program and Sandia National Laboratories, by designing and building a research furnace equipped with state-of-the-art diagnostics in the DOE Combustion Research Facility located at the Sandia site in Livermore, CA. Input on the configuration and objectives of the facility was sought from the entire industry by a variety of routes: (1) through a survey distributed to industry leaders by GMIC, (2) by conducting an open workshop following the OIT Glass Industry Project Review in September 1999, (3) from discussions with numerous glass engineers, scientists, and executives, and (4) during visits to ...

UK PubMed Central (United Kingdom)

The mechanism of influenza virus (INFV)-induced immunosuppression and the mode of inosiplex action against INFV infection were studied. INFV suppressed both anti-lipopolysaccharide and anti-sheep erythrocyte...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This book contains over 20 selections. Some of the titles are: Continuum damage mechanics studies on the dynamic fracture of concrete; Dynamic compressive strength of cementitious materials; Rate-sensitivity of mode I and mode II fracture concrete; and An impact damage model of concrete.

UK PubMed Central (United Kingdom)

BackgroundThe default mode network (DMN) is a set of brain regions that exhibit synchronized low frequency oscillations at resting-state, and is believed to be relevant to attention...Full Text Available

KoreaScience (Korea)

Full Text Available

CERN Document Server

The possibility of the existence of stable tetrahedral deformations at spin zero is investigated using the Skyrme-HFBCS approach and the generator coordinate method (GCM). The study is limited to nuclei in which the tetrahedral mode has been predicted to be favored on the basis of non self-consistent models. Our results indicate that a clear identification of tetrahedral deformations is unlikely as they are strongly mixed with the axial octupole mode. However, the excitation energies related to the tetrahedral mode are systematically lower than those of the axial octupole mode in all the nuclei included in this study.

Wastenet

complex -agriculture sector in a local community -blast furnace -cokes oven -cement kiln

CERN Document Server

Three dimensional rotatory modes of oscillations in a one-dimensional chain of rodlike charged particles or dust grains in a plasma are investigated. The dispersion characteristics of the modes are analyzed. The stability of different equilibrium orientations of the rods, phase transitions between the different equilibria, and a critical dependence on the relative strength of the confining potential are analyzed. The relations of these processes with liquid crystals, nanotubing, and plasma coating are discussed.

International Nuclear Information System (INIS)

It is shown that the section of the energy surface corresponding to the longitudinal mode by the principal xy-plane for the A-15 compounds will degenerate into four points at the corners of a square at very low temperatures in the cubic phase. When the quasi-shear mode propagating along the (110) direction becomes soft, simultaneously the longitudinal mode will exhibit unusually high phonon focussing. (author).

Energy Technology Data Exchange (ETDEWEB)

The Rotary Mode Core Sample System (RMCSS) is used to obtain stratified samples of the waste deposits in single-shell and double-shell waste tanks at the Hanford Site. The samples are used to characterize the waste in support of ongoing and future waste remediation efforts. Four sampling trucks have been developed to obtain these samples. Truck I was the first in operation and is currently being used to obtain samples where the push mode is appropriate (i.e., no rotation of drill). Truck 2 is similar to truck 1, except for added safety features, and is in operation to obtain samples using either a push mode or rotary drill mode. Trucks 3 and 4 are now being fabricated to be essentially identical to truck 2.

International Nuclear Information System (INIS)

An ultrasonic signal processing technique is applied to multi-mode arrival time estimation from Lamb waveforms. The basic tool is a simplified time-scale projection called a dynamic wavelet fingerprint (DWFP) which enables direct observation of the variation of features of interest in non-stationary ultrasonic signals. The DWFP technique was used to automatically detect and evaluate each candidate through-transmitted Lamb mode. The area of the dynamic wavelet fingerprint was then used as a feature to distinguish false modes caused by noise and other interference from the true modes of interest. The set of estimated arrival times were then used as inputs for tomographic reconstruction. The Lamb wave tomography images generated with these estimated arrival times were able to indicate different defects in aluminum plates.

Energy Technology Data Exchange (ETDEWEB)

An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without ...

Energy Technology Data Exchange (ETDEWEB)

Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD), which has a large shear, complicates the analysis of the ECE spectrum. In a sheared magnetic field the propagation of X and O-mode polarization through the plasma are coupled, causing mode conversion and polarization rotation. Mode scrambling is also caused by wall reflections. In this report, this mode conversion in LHD is numerically analyzed. It was found that at low density mode conversion scrambles the ECE spectra. However, at higher density (n{sub eo} > 1.0{center_dot}10{sup 19} m{sup -3}) the polarization mode is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Wall reflections ...

International Nuclear Information System (INIS)

Previous flow regime studies have been for horizontal, vertical, and inclined pipe flow. As such, only a few studies have been performed on bundle geometries. The present paper examines the flow regimes for a vertical hexagonal flow channel with and without a finned fuel bundle. This type of a 36 finned rod hexagonal fuel bundle in parallel hexagonal flow channels is used in a MAPLE (Multi- purpose Applied Physics Lattice Experimental) type nuclear reactor. An experiment apparatus was designed consisting of the flow channel, inlet plenum and an air-water separator. The inlet plenum is used to provide a uniform mixture of air and water before entering the hexagonal flow channel. A turbine flow meter is used to determine the water flow rate. The turbine flow meter is calibrated for a low flow range and limits the measurable flow to 50 l/min. Flow pattern observation is determined by a SONY video camera, Real-Time Neutron Radiography, pressure transducer and ...

International Nuclear Information System (INIS)

A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average value is 0:70 +- 0:09 mm. (author)

International Nuclear Information System (INIS)

As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT 1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical imagings by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the rating method. The area under the ROC curve was 91.6#+-#2.6% via satellite, and ...

Energy Technology Data Exchange (ETDEWEB)

A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. Imaging techniques such as real-time video, high speed video, and ...

Energy Technology Data Exchange (ETDEWEB)

Electric utilities are actively seeking ways of optimizing the economics of their operations by improving productivity and reducing time and money spent on maintenance. Iberdrola, a Spanish utility, is using advanced machine condition-monitoring technology to centralize control and maintenance of its hydropower projects as a means of achieving those goals. The company is using a blend of technologies to supervise their projects from a regional control center. The monitoring scheme makes use of data from on-line, machine-condition monitors, displays from in-plant audio asnd video equipment, and analysis from the control center`s SCADA system.

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Site has successfully used robots, teleoperators, and remote video to reduce exposure to ionizing radiation, improve worker safety, and improve the quality of operations. Previous reports have described the use of mobile teleoperators in coping with a high level liquid waste spill, the removal of highly contaminated equipment, and the inspection of nuclear reactor vessels. This report will cover recent applications at the Savannah River, as well as systems which SRS has delivered to other DOE site customers.

Energy Technology Data Exchange (ETDEWEB)

An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation.

Energy Technology Data Exchange (ETDEWEB)

The effects of automation and optimization on the day-to-day activities of oil field operators are sketched in this lead-in editorial comment on a series of articles designed to provide an overview of the revolution that computers have brought to the petroleum industry. The articles that follow detail the role of databases in tracking production information, new system architectures based on common integrated data repositories that provide corporation-wide access, the way video and single-site supervisory control and data acquisition are combined to control wellsite production, and a case study about the integrated processes introduced by Wascana Energy to automate its fields.

International Nuclear Information System (INIS)

The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)

Wastenet

...Heinz Dahl: presenting offshore wind energy for Australia NexTgen Wind. Next month, Heinz L Dahl will speak about offshore wind energy and its prospects for Australia. Skip to the navigation. Skip to the content. Events Models Movements Opinion Policies Research SCRT Videos Seeking ... August guest speaker: Heinz Dahl, managing director, NexTgen Wind. Next month, Heinz L Dahl will speak about offshore wind energy and its prospects for Australia. Heinz is the managing director of NexTgen Wind, a leading edge company that is focused on the cost ...

DEFF Research Database (Denmark)

Promoted as the first academic conference to be held completely in graphical cyberspace, Avatars 98 took place in November 1998. The virtual conference site was built and inhabited using software that supports multi-party presence over the Internet in a simulated, navigable environment. During the conference, avatar-embodied speakers using text chat performed to virtual audiences, 'webcams' (re)broadcast live video images of CNN and other remote sites, and a 'webcast' sent audiovisual representations captured by video camera of certain key participants in their physical locations. Such a novel and spectacular multi-media event raises many questions. How do we conceive of the recent developments in media technology and social computing that are impacting on what we have traditionally called 'the mass media'? How is interaction and talk mediated and adapted to new media genres? And how do participants construct and maintain senseful talk in a ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to investigate the feasibility of visualization and void fraction measurement of air-water two-phase flow in a small diameter tube (I.D.: 4.08 mm) by using the real-time neutron radiography and image processing techniques. Video images of two-phase flow were taken by using the real-time neutron radiography system (thermal neutron radiography facility No.2) installed at the Japan Research Reactor 3M of the Japan Atomic Energy Research Institute. The shape of bubbles and its moving behavior were clearly observed from the video images. The image corrections for dark current, shading, field intensity fluctuation and electrical system drift were examined in order to measure the void fraction from the video images. Though, generally speaking, the effect of the scattered neutron could not be ignored for quantification of the images taken by the neutron radiography, the scattered neutron could not ...

International Nuclear Information System (INIS)

The purpose of this study is to investigate the feasibility of visualization and void fraction measurement of air-water two-phase flow in a small diameter tube (I.D.: 4.08 mm) by using the real-time neutron radiography and image processing techniques. Video images of two-phase flow were taken by using the real-time neutron radiography system (thermal neutron radiography facility No.2) installed at the Japan Research Reactor 3M of the Japan Atomic Energy Research Institute. The shape of bubbles and its moving behavior were clearly observed from the video images. The image corrections for dark current, shading, field intensity fluctuation and electrical system drift were examined in order to measure the void fraction from the video images. Though, generally speaking, the effect of the scattered neutron could not be ignored for quantification of the images taken by the neutron radiography, the scattered neutron could not ...

Energy Technology Data Exchange (ETDEWEB)

Washboard (WB) modes (Smeulders P et al 1999 Plasma Phys. Control. Fusion 41 1303) are a very common edge instability regularly observed in the H-mode regime in JET. They are detected as (normally several) bands of continuously fluctuating magnetic activity rotating in the direction of the electron diamagnetic drift with typical frequencies in the range of 10-90 kHz. The time evolution of the WB mode frequency is found to follow qualitatively the evolution of the electron temperature measured near the pedestal top, probably due to the strong diamagnetic drift associated with the large pedestal gradients. Evidence for their involvement in the pedestal and ELM dynamics will be presented. Increasing WB mode amplitude is correlated with an increase in the time between consecutive type-I ELMs. In situations in which a sudden increase (decrease) of WB mode activity is observed, the ...

International Nuclear Information System (INIS)

In this paper, a relatively high gain (#approx =# 25 to 40 percent) free-electron laser (FEL) with an optical ring resonator is simulated using the code FELEX. The laser system corresponds to the ''burst mode'' FEL scheduled for operation at Boeing Aerospace Company in 1988. The ring consists of paraboloids, grazing incidence by hyperboloids, and a grating rhomb. The wiggler is 5 m in length and has an adjustable taper, while the electron beam is produced by an RF linac. The optical elements of the ring together with the FEL interaction in the wiggler are modeled in three spatial dimensions to investigate the system from start-up to saturation. Both single frequency and finite pulse simulations are performed. The study illustrates the necessity of mode matching the loaded resonator to maximize the extraction efficiency. The mode matching is necessary because the FEL interaction significantly alters the optical beam focus ...

CERN Document Server

We investigate strong nonlinear damping effects which occur during high amplitude oscillations of neutron stars, and the gravitational waves they produce. For this, we use a general relativistic nonlinear hydrodynamics code in conjunction with a fixed spacetime (Cowling approximation) and a polytropic equation of state (EOS). Gravitational waves are estimated using the quadrupole formula. Our main interest are $l=m=2$ $f$-modes subject to the CFS (Chandrasekhar, Friedman, Schutz) instability, but we also investigate axisymmetric and quasi-radial modes. We study various models to determine the influence of rotation rate and EOS. We find that axisymmetric oscillations at high amplitudes are predominantly damped by shock formation, while the non-axisymmetric $f$-modes are mainly damped by wave breaking and, for rapidly rotating models, coupling to non-axisymmetric inertial modes. From the observed ...

International Nuclear Information System (INIS)

We study the production of three gauge bosons (W"+W"-Z"0 and W"+W"-#gamma#) at the next generation of linear e"+e"- colliders operating in the #gamma##gamma# mode. We analyze the total cross sections as well as several kinematical distributions of the final state particles. We find out that a linear e"+e"- machine operating in the #gamma##gamma# mode will produce 5--10 times more three-gauge-boson states compared to the standard e"+e"- mode at high energies.

Energy Technology Data Exchange (ETDEWEB)

Information that describes the use of the Otto cycle engines in transportation is summarized. The transportation modes discussed in this report include the following: automobiles, light trucks, heavy trucks, marine, recreational vehicles, motorcycles, buses, aircraft, and snowmobiles. These modes account for nearly 100% of the gasoline and LPG consumed in transportation engines. The information provided on each of these modes includes descriptions of the average energy conversion efficiency of the engine, the capital stock, the amount of energy used, and the activity level as measured in ton-miles. Estimates are provided for the years 1980 and 2000.

Energy Technology Data Exchange (ETDEWEB)

Solid-state acoustic sensors for monitoring conditions at a surface immersed in a liquid and for monitoring concentrations of species in a liquid and for monitoring electrical properties of a liquid are formed by placing interdigital input and output transducers on a piezoelectric substrate and propagating acoustic plate modes therebetween. The deposition or removal of material on or from, respectively, a thin film in contact with the surface, or changes in the mechanical properties of a thin film in contact with the surface, or changes in the electrical characteristics of the solution, create perturbations in the velocity and attenuation of the acoustic plate modes as a function of these properties or changes in them.

Energy Technology Data Exchange (ETDEWEB)

Measurements of the relaxation of the D{sub 2}O stretch mode in vitreous As{sub 2}S{sub 3} are presented. Because the bending mode of the molecule offers an intra-molecular decay channel for the stretch mode, the decay scheme of the D{sub 2}O molecule is more complex than that of diatomic molecules. The asymmetric stretch mode of D{sub 2}O has a frequency of 2680 cm{sup -1}. To study the relaxation of this mode we applied a pump-probe technique, using intense psec; pulses of the Stanford Free Electron Laser. Due to the small cross-section of the vibrational mode, successful efforts were made to improve the signal to noise ratio by using a laser stabilization system and a tightly focused beam to increase the intensity, by averaging the signal with a kHz repetition rate and by using samples with an optimized D{sub 2}O concentration. A rapid relaxation rate on the ...

Science.gov (United States)

The authors report on temperature dependent characteristics and single mode performance of one-wave cavity, planar implanted, AlGaInP-based vertical-cavity surface emitting lasers. By optimizing the overlap between the gain peak and the cavity mode of the structure, they demonstrate record device performance, including 8.2 mW maximum output power and 11% power conversion efficiency for multimode operation and 1.9 mW and 9.6% power conversion efficiency for single mode operation at 687 nm. Improved performance at elevated temperatures is also achieved, with 1.5 mW output power demonstrated at 50 C from a 15-{micro}m-diameter device.

British Library Electronic Table of Contents (United Kingdom)

The microdynamics of soliton waves and localized modes of nonlinear vibrations of the acoustic and optical types in uranium nitride has been investigated. It has been shown that, with an increase in the excitation energy in the spectral gap between the bands of optical and acoustic phonons, the energies of solitons increase, whereas the energies of local modes decrease. The previously experimentally observed unidentified quasi-resonant features, which shift in the gap with variations in the temperature, can represent the revealed soliton waves and local modes. The microdynamics of heat conduction of uranium nitride has been studied for the stochastic generation of soliton waves and local modes in the case of spatially distant energy absorption. The thermal conductivity coefficient determin...

CERN Document Server

Within a fully relativistic framework, we derive and solve numerically the perturbation equations of relativistic stars, including the stresses produced by a non-vanishing shear viscosity in the stress-energy tensor. With this approach, the real and imaginary parts of the frequency of the modes are consistently obtained. We find that, approaching the inviscid limit from the finite viscosity case, the continuous spectrum is regularized and we can calculate the quasi-normal modes for stellar models that do not admit solutions at first order in perturbation theory when the coupling between the polar and axial perturbations is neglected. The viscous damping time is found to agree within factor 2 with the usual estimate obtained by using the eigenfunctions of the inviscid limit and some approximation for the energy dissipation integrals. We find that the frequencies and viscous damping times for relativistic $r-$modes lie ...

Energy Technology Data Exchange (ETDEWEB)

The Muon Ionization Cooling Experiment (MICE) focusing solenoid magnets focus the muon beam within the MICE cooling channel on a liquid or solid absorber that is within the warm bore of solenoid. The focusing magnet has a warm bore of 470 mm. his magnet consists of two coils 210-mm long that is separated by an aluminum mandrel that is 200 mm long. Each of the coils has its own leads. The coils may be operated in either the non-flip mode (solenoid mode with both coils at the same polarity) or the lip mode (quadrupole focusing mode where both coils are at opposite polarity). This report describes the focusing solenoid magnet design that will be built by the vendor. The progress on the construction of the first of the focusing magnets will also be discussed in this report. Ultimately three of these magnets will be built. These magnets will be cooled using a pair 1.5 W (at 4.2 K) pulse tube coolers.

International Nuclear Information System (INIS)

We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.

Science.gov (United States)

... one for each node, and an i/o queue to manage ... ecuted as if it came from a terminal attached to a ... In its default mode PC-NETSIM is stochastic, that is ...

International Nuclear Information System (INIS)

Natural cooling conditions of the nuclear fuel in the channel type reactor after its shut down are commonly determined with relatively high uncertainty. This is not only to he lack of adequate measurements of thermal parameters i.e. the residual power generation, the coolant flow and temperatures, but also due to indeterminate model of convection mechanism. The numerical simulation of natural convection in multitube fuel assembly in the fuel channel leads to various convection modes including evidently chaotic behaviour. To determine the real cooling conditions in the MARIA research reactor a series of experiments has been performed with fuel assembly equipped with a set of thermocouples. After some forced cooling period (the shortest was half an hour after the reactor shut down) the reactor was left with the only natural convection. Two completely different cooling modes have been observed. The MARIA core consists of series of individual fuel ...

Energy Technology Data Exchange (ETDEWEB)

Dynamic stability enhancement of composite mode oscillations of interconnected power systems by means of a hybrid power system stabilizer is discussed here. The proposed Hybrid PSS is of a two-level structure composed of a local PSS for local mode and a global PSS for inter-area mode damping. Here, the input of the global stabilizer is the center of inertia speed deviation of slow-coherent generators. The paper is focused on the practical considerations in implementation of the proposed stabilizer. First, the optimum allocation of this stabilizer is discussed. The authors introduce an index of mode-input-assignability, by which the best sites of the stabilizer can be identified. Next, for practical applications, an estimation method for the approximation of the input of the global PSS is introduced. An approximated value of the center of inertia speed is obtained from a suitable combination of the rotor ...

Energy Technology Data Exchange (ETDEWEB)

The role of shear in determining the ideal MHD stability properties of tokamaks is discussed. In particular, we assess the effects of low shear within the plasma upon pressure-driven modes. The standard ballooning theory is shown to break down, as the shear is reduced and the growth rate is shown to be an oscillatory function of n, the toroidal mode number, treated as a continuous parameter. The oscillations are shown to depend on both the pressure and safety-factor profiles. When the shear is sufficiently weak, the oscillations can result in bands of unstable n values which are present even when the standard ballooning theory predicts complete stability. These instabilities are named ''infernal modes.'' The occurrence of these instabilities at integer n is shown to be a sensitive function of q-axis, raising the possibility of a sharp onset as plasma parameters evolve. 20 refs., 31 figs.

Science.gov (United States)

... The subjects in this field experiment were volunteer infantrymen from the 82nd Airborne Division and the 101st Airborne Division (Air Assault). ...

Energy Technology Data Exchange (ETDEWEB)

Due to the well-establish corrosion problems of Alloy 600 as a steam-generator material and the subsequent focus on thermally treated (TT) Alloy 690 and Alloy 800 as alternative materials, a systematic analysis of the corrosion behavior of these two latter alloys is warranted. Corrosion test results for Alloys 690 TT and 800 were collected and organized in the form of corrosion mode diagrams. Selected data for mill annealed (MA) Alloy 600 were also included for reference. The corrosion mode diagrams correlate the modes of corrosion degradation observed in tests as functions of the environment pH and electrochemical potential (ECP). The diagrams confirm that Alloys 690TT shows some susceptibility in caustic environments, and Alloy 800 shows susceptibility in both caustic and highly acidic environments. (authors). 6 figs., 5 refs.

Science.gov (United States)

Externally powered prostheses have been studied for many years, to provide more effective rehabilitation of amputees. To take advantage of the benefits offered by external power in prostheses, however, the mode of control of the prosthesis by the amputee ...

UK PubMed Central (United Kingdom)

OBJECTIVE: To review the body of international literature regarding lung surfactant supplements in order to determine: 1) the current knowledge of the antenatal routes of administration of surfactant...Full Text Available

Science.gov (United States)

A Pulsed Radiation Dosimetry System designed to measure radiation produced by particle accelerators is described. The problems associated with total-dose measurement of irregular shaped pulses of ionizing radiation have been simplified. The system responds to extremely narrow pulses of charged particles or X-rays using a pin diode as the detector. Direct readout of dose in rads (Si) is displayed on a 3-1/2 digit digital panel meter. The system will operate in either the multiple-pulse or single-pulse mode. The multiple-pulse mode would be useful in monitoring or tuning a linear accelerator. In the single-pulse mode the system will automatically display total dose of a transient event in real time and hold that measurement indefinitely or until the next measurement is made. The system features an automatic reset in either mode.

UK PubMed Central (United Kingdom)

The modes of action of the five major endo-(1----4)-beta-D-glucanases (I, II, III, IV and V) purified from Penicillium pinophilum cellulase were compared by h.p.l.c. analysis, with normal, 1-3H-labelled...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A CO/sub 2/ laser chain able to supply approx.=30 MW on a single mode TEM/sub 00/ is described. The coupling of a modified Lumonics 101 module with a low-pressure cell constitues the oscillator and two further Lumonics 103 stages two amplifiers. The final pulse achieves the energy of 4.0 J with 90% of this energy in a peak of 100 ns FWHM.

International Nuclear Information System (INIS)

Photonic band gap structures with single or multiple defects show potential for use in single-beam and multi-beam klystrons and particle accelerators. The primary concerns are the coupling between the modes at each individual defect site and the damping of unwanted higher order modes. A conceptual design of a PBG based, multi-beam klystron and methods to damp HOMs and to cool and tune the structure are presented.

Energy Technology Data Exchange (ETDEWEB)

We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in {gamma}{gamma} mode at the TeV energy scale. Final states with one or two H{sup {+-}} bosons are considered, as produced by both tree- and loop-level interactions. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A gas-diesel dual fuel engine apparatus is described having a diesel engine, a diesel fuel supply system including a diesel fuel injection pump, a gaseous fuel supply system including a gaseous fuel regulating valve, and a governing and controlling device for governing the speed of the engine through the control of fuel supplied to the engine and controlling the switchover of the operation of the engine between a diesel fuel mode and a gaseous fuel mode. The improvement of the governing and controlling device consists of: (a) at least one electronic governor means adapted to compare a speed signal representing the actual operating speed of the diesel engine with a set speed signal representing the set speed thereof; (b) a pair of electric actuator means having respective power amplifier circuits and mechanically connected to the diesel fuel injection pump and the gaseous fuel regulating valve, respectively, for the actuation thereof; (c) ...

CERN Document Server

Predictions and measurements of a multimode waveguide interferometer operating in a fibre coupled, ``dual-mode'' regime are reported. With a 1.32 micrometer source, a complete switching cycle of the output beam is produced by a 10.0 nanometer incremental change in the 8.0 micrometer width of the hollow planar mirror waveguide. This equates to a fringe spacing of $\\sim\\lambda /130$. This is an order of magnitude smaller than previously reported results for this form of interferometer.

Energy Technology Data Exchange (ETDEWEB)

This document provides data on aerosol concentrations in tank head spaces, total mass of aerosols in the tank head space and mass of aerosols sent to the exhauster during Rotary Mode Core Sampling from November 1994 through June 1999. A decontamination factor for the RMCS exhauster filter housing is calculated based on operation data.

Energy Technology Data Exchange (ETDEWEB)

Different sized ROIs within the femoral head and different modes of calculation were used in (/sup 99m/Tc)MDP scintimetry after femoral neck fracture. In preoperative scintimetry, correction for increased trochanteric uptake gave the best discrimination, whereas in postoperative scintimetry the direct ratio fractured/intact femoral head was superior. The change in ROI size had little influence.

International Nuclear Information System (INIS)

The high-frequency precessional mode of a hot-electron-stabilized magnetic configuration has previously been shown to be stable in a window of core-plasma mass. Under conditions of frequency matching, the resulting stable negative-energy precessional wave can be destabilized by coupling to positive-energy shear-Alfven waves. Coupling is avoided when the hot-electron precession frequency exceeds the core-plasma ion gyrofrequency.

CERN Document Server

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.

CERN Document Server

The PLL (Phase Locked Loop) has two modes: search mode and locking mode. The mode is determined by how far apart the internal frequency is from the external frequency. When the internal - and exter nal frequencies are close, the PLL is in locking mode. While locking on the external frequency, the PLL can largely be expressed as a linear term superimposed with a small "noise" term. We can t herefore calculate a transfer function that will completely describe the performance of the PLL apart from the precision, which is determined by the noise term. Two ideas are presented on how to re duce the noise term. The first idea is to compensate the noise term with an equal value of opposite sign. This completely removes the noise when the PLL locks on a steady frequency. Unfortunately it can not be used for the LEP Q-meter which is plagued by the presence of satellite frequencies. For other ...

Energy Technology Data Exchange (ETDEWEB)

A newly developed discrete-time adaptive sliding mode power system stabilizer (PSS) is proposed in this paper. Because the proposed PSS is developed in the pure discrete-time domain it is able to maintain the stability with the rather slower smapling frequency compared to discretized conventional continuous-time sliding mode PSS. The proposed PSS has the three main superiorities to the conventional PSS. First, because the proposed PSS utilizes the sliding mode control method, it has the strong robustness to the variations of the system parameters. Hence, it can overcome the minor disturbances such as identification errors, modeling errors, etc. Second, the proposed PSS needs only input/output measurements as feedback signals. Hence, it does not need the measurements of the state variables as the conventional sliding mode PSS or PSS based on the linear quadratic control method does. Finally, because the ...

International Nuclear Information System (INIS)

MR images of steady and pulsatile disturbed flow, obtained with use of flow-compensated spin-echo (SE) and cine pulse sequences, revealed excellent flow visualization in three dimensions. Phantoms, built from molds of actual blood vessels, reproduced laminar, disturbed, or turbulent flow. Video recording (VR), performed under conditions equivalent to those of the MR experiments, showed separation zones identical to those seen on SE images. Pulsatile flow studies showed complex patterns of vortical flow on cine images and VR. Varying pulse sequence details changed contrast but not flow patterns. The validation of MR observations by VR has implications for clinical cine imaging and low abnormal signals observed on MR angiograms.

Energy Technology Data Exchange (ETDEWEB)

Real-time neutron radiography has been used to study the dynamic behavior of two-phase flow and measure vapor fractions in a steam-water duct at atmospheric pressure. This unique experimental technique offers one the opportunity to observe and record on videotape now Patterns and transient behavior of two-phase flow inside opaque containers without perturbing the environment. The neutron radiographic technique is non-intrusive and requires no special transparent window region. Data are recorded simultaneously over a large area of interest. Image processing of the video data can be employed to measure bubble velocities and time-averaged and Instantaneous vapor fractions.

British Library Electronic Table of Contents (United Kingdom)

Background The crucial role of cigarette smoking in the development of pneumothorax is unclear because nonsmokers can also develop primary spontaneous pneumothorax. The purpose of this study was to clarify the pathophysiologic effects of cigarette smoking and its clinical correlations in primary spontaneous pneumothorax. Methods Included were 115 specimens of lung tissue from patients with primary spontaneous pneumothorax who underwent video-assisted thoracoscopic surgery from January 2001 to December 2002. We reviewed the clinical features of 56 smokers and 59 nonsmokers with an average follow-up of 67 months. The pathologic findings of resected lung specimens were analyzed retrospectively. Results There were no statistical differences in sex, age, body height, body weight, body mass inde...

British Library Electronic Table of Contents (United Kingdom)

It has been considered that dry-out occurs easily in boiling heat transfer for a small channel, a mini- or microchannel, because the channel was easily filled with coalescing vapor bubbles. In the present study, the experiments of subcooled flow boiling of water were performed under atmospheric conditions for a horizontal rectangular channel for which the size is 1 mm height and 1 mm width, with a flat heating surface of 10 mm length and 1 mm width placed on the bottom of the channel. The heating surface has a top of copper heating block and is heated by ceramic heaters. In the high heat flux region of nucleate boiling, about 70-80% of the heating surface was covered with a large coalescing bubble and the boiling reached critical heat flux as observed by high-speed video. In the beginning ...

Energy Technology Data Exchange (ETDEWEB)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Illinois. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain quantitative information on the object being imaged.

Wastenet

...Polymer Fuel Cells Challenge Publications News Events Login Register Search Content type All Web pages Case studies Publications News Video Home ...Buildings Carbon capture & storage Combined heat & power Electricity transmission & distribution Energy storage Fuel cells Geothermal Hydroelectric Hydrogen Industry Lighting Marine Metering Nuclear Solar Transport Wind ...Home Emerging technologies Current focus areas Polymer Fuel Cell Challenge Polymer Fuel Cells Challenge The objective of the Polymer Fuel Cells Challenge is to develop,...prove and commercialise novel polymer fuel cell technologies that have the potential to deliver a step-change in overall system cost. What are ...

Energy Technology Data Exchange (ETDEWEB)

A multiprocessor architecture inspired by the Disney multiplane camera is proposed. For many applications, this approach produces a natural mapping of processors to objects in a scene. Such a mapping promotes parallelism and reduces the hidden-surface work with minimal interprocessor communication and low-overhead cost. Existing graphics architectures store the final picture as a monolithic entity. The architecture here stores each object's image separately. It assembles the final composite picture from component images only when the video display needs to be refreshed. This organization simplifies the work required to animate moving objects that occlude other objects. In addition, the architecture has multiple processors that generate the component images in parallel. This further shortens the time needed to create a composite picture. In addition to generating images for animation, the architecture has the ability to decompose images.

Energy Technology Data Exchange (ETDEWEB)

A neutron imaging system (NIS) has been recently installed at the University of Texas TRIGA reactor facility. The imaging system establishes new capabilities for beam diagnostics at the Texas Cold Neutron Source (TCNS) for real-time neutron radiography (RTNR) and for neutron computed tomography (NCT) research. The NIS will also be used for other research projects. The system consists of two subsystems as follows: (1) Thomson 9-in. neutron image intensifier (NII) tube sensitive to cold, thermal, and epithermal neutrons, (2) image-processing unit consisting of vidicon camera, two high-resolution monitors, image enhancement and measurement processor, and video printer. The NIS is installed at the cold neutron beam of the TCNS for testing and cold neutron beam diagnostics.

CERN Document Server

We present a new modular traffic signs recognition system, successfully applied to both American and European speed limit signs. Our sign detection step is based only on shape-detection (rectangles or circles). This enables it to work on grayscale images, contrary to most European competitors, which eases robustness to illumination conditions (notably night operation). Speed sign candidates are classified (or rejected) by segmenting potential digits inside them (which is rather original and has several advantages), and then applying a neural digit recognition. The global detection rate is ~90% for both (standard) U.S. and E.U. speed signs, with a misclassification rate 150 minutes of video. The system processes in real-time ~20 frames/s on a standard high-end laptop.

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)

National Aeronautics and Space Administration (NASA)

GPM moves from the clean room to the test chamber on a dolly without wheels. Compressed air is pumped out under airpads that float the Spacecraft on a bed of air. nThe wind generated when the centrifuge moves at its maximum speed are more than 200 mph - that's tornado speed. But since they move with the centrifuge the satellites tested only feel 20 mph winds. nLeaning outward at 45 degrees for one test orientation, GPM comes within 28 inches of the wall. When lifted onto the platform it cleared the ceiling by only five inches. nNatural audio only. nVideo Credit: Brooke Harris n

Science.gov (United States)

The purpose of this study is to search for a new method of dispersing spilled heavy oil, which has a detrimental effect on the natural environment and marine ecosystem. A method ejecting a waterjet vertically downward to heavy oil on the water surface was studied, particularly focusing on the effect of the guide nozzle shape. The waterjet comprised heavy oil and minute air bubbles, and passed through the hole of the guide nozzle. Thirteen guide nozzle shapes were tested and compared. The dispersion efficiency of a tapered hole was the best among the 13 nozzles. The flow in the hole of the guide nozzles was recorded by a high-speed video camera. The occurrence of two flows, regular and counter flows, was observed in the taper guide nozzle. It seemed that the counter flows generated the shearing force between the waterjet and the heavy oil layer. It is considered that the shearing force determines the surplus efficiency of disperse.

CERN Document Server

Web conferencing tools have entered the mainstream of business applications. Using web conferencing for IEEE conferences has a good potential of adding value to both organizers and participants. Authors propose a concept of Truly Integrated Conference (TIC) according to which a multi-point worldwide-distributed network of conference online authors/participants will enhance the standard (centralized) IEEE conference model, which requires attendance of the participants in person at the main conference location. The concept entails seamless integration of the onsite and online conference systems, including data/presentation, video, audio channels. Benefits and challenges of the TIC concept are analyzed. Requirements to the web conferencing system capable of supporting the TIC conference are presented and reviewed against commercial web conferencing tools. Case study of the IEEE Toronto International Conference ? Science and Technology for Humanity, which was the first ...

Science.gov (United States)

In a nutshell, the existing Internet provides to us content in the forms of videos, emails and information served up in web pages. With Cloud Computing, the next generation of Internet will allow us to "buy" IT services from a web portal, drastic expanding the types of merchandise available beyond those on e-commerce sites such as eBay and Taobao. We would be able to rent from a virtual storefront the basic necessities to build a virtual data center: such as CPU, memory, storage, and add on top of that the middleware necessary: web application servers, databases, enterprise server bus, etc. as the platform(s) to support the applications we would like to either rent from an Independent Software Vendor (ISV) or develop ourselves. Together this is what we call as "IT as a Service," or ITaaS, bundled to us the end users as a virtual data center.

International Nuclear Information System (INIS)

Solid state nuclear track detectors (SSNTD) are widely used for radon measurements and CR-39 is one of the most popular SSNTD. In this work it was determined the calibration factor for radon concentration measurements through the passive method with CR-39 detectors. The detectors were put in a proper device (an adapted Lucas cell) and exposed to the standard radon concentration through the Pylon Model RN-150 flow through radon gas source. After exposure, the detectors were etched for 5.5 hours in a KOH solution at 80 deg C in a bath at a constant temperature. The track density was read in an Axiolab-Zeiss optical microscope, with nominal magnification of X10 connected to a video camera and to a personal computer. The calibration factor was obtained through the relation between standard radon concentration, track density and exposure time. (author)

International Nuclear Information System (INIS)

A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the U.S. Department of Energy's remedial action survey programs. The unit consists of NaI(Tl) detectors housed in a specially equipped van. The system is operator controlled through an on-board minicomputer with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided on floppy disk. Multichannel analysis capabilities are included for qualitative radionuclide identification. A "2"2"6Ra-specific algorithm is currently employed to identify locations containing residual radium-bearing materials.

Energy Technology Data Exchange (ETDEWEB)

Silica microspheres were deposited into two-dimensional periodic arrays and coated with a thin layer of silicon nanocrystals. The luminescence from the silicon nanocrystals coupled into the whispering gallery modes of the spheres, with Q factors that depended on a range of parameters including sphere size, position on the sphere, viewing direction, and thickness of the nanocrystal coating. Scattering from the film-sphere and/or the sphere-substrate contacts resulted in a lower Q for modes that intersect these regions. The highest Q factors obtained in this work were {approx}1500. The results suggest that silica microspheres may be promising candidates for high-Q cavities that incorporate silicon nanocrystals for cavity QED or nonlinear optical effects.

International Nuclear Information System (INIS)

We consider a SQUID ring inductively coupled to an electromagnetic field mode, both treated quantum mechanically. We demonstrate a method for creating a maximally entangled state between the ring and the field mode. Our method utilises a non-adiabatic external magnetic flux pulse to move into and out of a transition region. Hence, our approach is fundamentally different to techniques based on Landau-Zener tunnelling that can also be used to achieve similar results. Our analysis is extended to include the effects of coupling the system to a dissipative environment. With this model we show that although such an environment makes a noticeable difference to the time evolution of the system, it need not destroy the entanglement of this coupled system over time scales required for quantum technologies.

Energy Technology Data Exchange (ETDEWEB)

A novel system for real-time radiation monitoring in reactor or accelerator facilities has been studied using an imaging plate. The authors made a feasibility study on a new neutron detection system using both photostimulated luminescence (PSL) and prompt luminescence (PL) generated in a neutron imaging plate (NIP) when the NIP is irradiated by neutrons. A readout system consisting of a semiconductor laser and a photomultiplier tube was fabricated for the purpose. It was confirmed that the system can measure both PSL and PL, where Am-Li was used as a neutron source. It may be possible to establish a new wide-range neutron monitoring system using the developed system as a PL mode normally, and as a PSL mode in case of intense neutron dose that cannot be measured in a PL mode because of saturation of the detection system. (author)

International Nuclear Information System (INIS)

InP-quantum dots (QDs) are promising sources of single-photons and as active laser medium, emitting in the red part of the visible spectrum and thus in the range of the highest sensitivity of current silicon detectors. The self assembled QDs were grown by metal organic vapor phase epitaxy and are embedded in between distributed Bragg reflectors (DBRs), afterwards the sample was processed by a Focused Ion Beam to fabricate micro-pillars. The DBRs and the high refractive index step between pillar and air results in a three dimensional mode confinement and highly directed emission and thus higher intensity. We have investigated the mode spectra by micro-photoluminescence measurements for different pillar diameters and compared the spectra with a theoretical model showing up good consistency. Q-factors up to 3600 were achieved.

British Library Electronic Table of Contents (United Kingdom)

Various SST indices in the Indo-Pacific region have been proposed in the literature in light of a long-range seasonal forecasting of the Indian Summer Monsoon (ISM). However, the dynamics associated with these different indices have never been compared in detail. To this end, the present work re-examines the variabilities of ISM rainfall, onset and withdrawal dates at interannual timescales and explores their relationships with El Ni?o-Southern Oscillation (ENSO) and various modes of coupled variability in the Indian Ocean. Based on recent findings in the literature, five SST indices are considered here: Ni?o3.4 SST index in December?January both preceding [Nino(?1)] and following the ISM [Nino(0)], South East Indian Ocean (SEIO) SST in February?March, the Indian Ocean Basin (IOB) mode in ...

Energy Technology Data Exchange (ETDEWEB)

The electron cyclotron resonance layer in a tokamak, {omega}={omega}{sub c}(r), is not accessible by the extraordinary wave from the low field side, because it is shielded by a cutoff layer. However, a X-mode launched with a nonzero toroidal angle propagates at the cutoff parallel to the magnetic field and has a circular polarization. Therefore it can already at the cutoff layer interact efficiency with electrons via the Doppler shifted resonance. The driven current can be substantially higher than that driven by the second harmonic X-mode. The applicability of this current drive scheme is limited to rather low values of {omega}{sub p}{sup 2}/{omega}{sub c}{sup 2}, but may be of interest for high magnetic field devices. (author)

British Library Electronic Table of Contents (United Kingdom)

Abstract We performed hydrodynamical simulations to investigate the formation and evolution of protostars and circumstellar discs from the pre-stellar cloud. As the initial state, we adopted the molecular cloud core with two non-dimensional parameters representing the thermal and rotational energies. With these parameters, we derived 17 models and calculated the cloud evolution--104 yr-after the protostar formation. We found that early evolution of the star-disc system can be qualitatively classified into four modes: the massive-disc, early-fragmentation, late-fragmentation, and protostar-dominant modes. In the -massive-disc mode-, to which the majority of models belong, the disc mass is greater than the protostellar mass for over 104 yr and no fragmentation occurs in the circumstellar dis...

International Nuclear Information System (INIS)

A very simple theoretical scheme is proposed to implement two- and three-qubit controlled-phase gates firstly only using a single resonant interaction between ladder-type three-level atoms and the single-mode cavity. In the presented protocol, the quantum information is encoded on the stable ground states of the atoms (as the controlling qubits) and the zero- and one-photon Fock states of cavity-field (as the target qubit). Under the influence of the atomic spontaneous emission, the decay of the cavity-mode, and deviation of the coupling strength, the three-qubit controlled-phase gate may have a comparatively high fidelity. The experimental feasibility of controlled-phase gate and the case that is extended to realize N-qubit controlled-phase gate are also discussed. (general)

International Nuclear Information System (INIS)

To develop a work in an area with high radiation, it requires of a detailed knowledge of the surroundings work, a communication and effective vision, a near dosimetric control. In a work where the spaces variables and reduced accesses exist, noise that hinders the communication, defendant operative condition, radiation field and taking of decision, it is necessary to have tools that allow a total control of the environment to make opportune and effective decisions, there where the task is developed. Under this elementary concept, it was developed in the Laguna Verde Central a project that it allowed a mechanism, interactive of control in spaces complex; to see, to hear, to speak, to measure. This concept takes to the creation of an equipped system with closed circuit of television, wireless communication systems, tele dosimetry wireless systems, VHS and DVD recording equipment, uninterrupted energy units. The system requires of an electric power socket, and the installation of two ...

Energy Technology Data Exchange (ETDEWEB)

The Transportation Energy Data Book: Edition 12 is a statistical compendium prepared and published by Oak Ridge National Laboratory under contract with the Office of Transportation Technologies in the Department of Energy. Designed for use as a desk-top reference, the data book represents an assembly and display of statistics and information that characterize transportation activity, and presents data on other factors that influence transportation energy use. The purpose of this document is to present relevant statistical data in the form of tables and graphs. Each of the major transportation modes--highway, air, water, rail, pipeline--is treated in separate chapters or sections. Chapter 1 compares US transportation data with data from seven other countries. Aggregate energy use and energy supply data for all modes are presented in Chapter 2. The highway mode, which accounts for over three-fourths of total transportation ...

UK PubMed Central (United Kingdom)

We use a novel normal mode analysis of an elastic network model drawn from configurations generated during microsecond all-atom molecular dynamics simulations to analyze the mechanism of auto-inhibition...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundInternationally, there is increasing use of telephone consultations, particularly for triaging requests for acute care. However, little is known about how this mode of...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundBuruli ulcer, the third mycobacterial disease after tuberculosis and leprosy, is caused by the environmental mycobacterium M. ulcerans. Various modes of...Full Text Available

Science.gov (United States)

... presumed first instar Geocharidius. Anillines occur in deep forest litters, beneath rocks and in soil (endogean), or as ... their small size and cryptic mode of life. Forest litter inhabiting anillines ma...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Various energy sources and motors of divers types can be used in electric cars with operating modes subjected to a number of particular constraints. As a result, the possible structures of the converters, that are analysed in detail, are about a dozen in number. Also considered is the use of solid-state components - thyristors, power transistors and new components.

UK PubMed Central (United Kingdom)

RNase BN, the Escherichia coli homolog of RNase Z, was previously shown to act as both a distributive exoribonuclease and an endoribonuclease on model RNA substrates and to be inhibited...Full Text Available

UK PubMed Central (United Kingdom)

ObjectiveTo investigate the effect of maternal obesity on mode of delivery following induction of labour (IOL) for prolonged pregnancy and subsequent intrapartum and neonatal complications.DesignRetrospective...Full Text Available

UK PubMed Central (United Kingdom)

By use of a new computer-assisted u.v.-spectrophotometric assay method, the kinetic parameters of the reaction catalysed by Bacillus licheniformis 749/C beta-lactamase were re-examined and the mode...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe study aimed at (i) characterizing the mode of transmission of bla_CTX-M and bla_TEM-1 among extended-spectrum-β-lactamase...Full Text Available

UK PubMed Central (United Kingdom)

Background and AimsMany plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized...Full Text Available

UK PubMed Central (United Kingdom)

Tamoxifen (TAM) is a selective estrogen receptor modulator widely used in the prevention and treatment of breast cancer. A major mode of metabolism of the major active metabolites of TAM, 4-OH-TAM...Full Text Available

UK PubMed Central (United Kingdom)

We used the idea of hierarchical control to study multi-muscle synergies during a whole-body sway task performed by a standing person. Within this view, at the lower level of the hierarchy,...Full Text Available

UK PubMed Central (United Kingdom)

Alternatives for developing chronic exposure limits for noncancer effects of trichloroethylene (TCE) were evaluated. These alternatives were organized within a framework for dose-response assessment--exposure:dosimetry...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A micro-mechanistic understanding of bone fracture thatencompasses how cracks interact with the underlying microstructure anddefines their local failure mode is lacking, despite extensive research nthe response of bone to a variety of factors like aging, loading, and/ordisease.

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 ...

Energy Technology Data Exchange (ETDEWEB)

Operating the Stanford Linear Collider (SLC) at 120Hz repetition rate requires the presence of two bunches in both the electron and the positron damping ring. The {pi}-mode instability, a coupled bunch instability where the two bunches oscillate with a phase difference of 180{degrees}, had been observed in both rings with low current thresholds of 7{sup *}10{sup 9} particles per bunch. To avoid the instability, the RF system had to be operated in ways which in general reduced the cavity gap voltages and required constant operational attention. For the 1992 running cycle a passive cavity was installed and successfully tested. It is tuned to the frequency of the lower synchrotron oscillation sideband of an odd revolution harmonic. The impedance of the cavity then damps {pi}-mode oscillations very similar to the Robinson damping provided by the main RF cavities which damps O-mode synchrotron oscillations. In this report we ...

UK PubMed Central (United Kingdom)

The hierarchical arrangement of collagen and mineral into bone tissue presumabley maximizes fracture resistance with respect to the predominant strain mode in bone. Thus, the ability of cortical...Full Text Available

International Nuclear Information System (INIS)

The predicted results of INDAC code were compared with measured "3H concentrations in air and pine-needle around the Wolsung site. The optimal sets of input data to INDAC were in addition selected by comparing the measured values with the predicted values of INDAC based on various conditions such as the release modes of effluents into the environment, the classification of wind classes, and the consideration of terrain. The predicted "3H concentrations in air and pine-needle were shown to have good agreement with measured values, although there are some limitations such as uncertainties in measured values, complex topology around the site, and the land-sea breeze effects. The assumption on the "3H behavior in vegetables or plants that the ratio of "3H concentration in plant water to "3H concentration in atmospheric water is 1/2 was shown to be conservative in terms of the audit calculation performed by the regulator. It was also found that data sets based on mixed ...

Science.gov (United States)

A survey of theoretical research on acoustic plasmons is given and prospects for the observation of these elusive modes are examined. Possible acoustic plasmon contributions to the transition temperatures of the superconducting A-15 compounds are considered. Directions for future experiments and theory are suggested.

Energy Technology Data Exchange (ETDEWEB)

We study the constraints on the anomalous coupling {ital g}{sub 5}{sup {ital Z}} that can be obtained from the analysis of the reaction {gamma}{gamma}{r_arrow}{ital W}{sup +}{ital W}{sup {minus}}{ital Z} at future linear {ital e}{sup +}{ital e}{sup {minus}} colliders. We find out that a 0.5 (1) TeV {ital e}{sup +}{ital e}{sup {minus}} collider operating in the {gamma}{gamma} mode can probe values of {ital g}{sub 5}{sup {ital Z}} of the order of 0.15 (4.5{times}10{sup {minus}2}) for an integrated luminosity of 10 fb{sup {minus}1}. This shows that the ability to search for this anomalous interaction of the {gamma}{gamma} mode is better than the one of the usual {ital e}{sup +}{ital e}{sup {minus}} mode, and it is similar to the ability of the {ital e}{gamma} mode.

Energy Technology Data Exchange (ETDEWEB)

A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

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 are presented with engine operation in a ...

UK PubMed Central (United Kingdom)

BackgroundThere are various treatment options for congenital melanocytic nevus (CMN), including surgical excision, dermabrasions, curettage, laser treatment, chemical peels and cryosurgery....Full Text Available

International Nuclear Information System (INIS)

Mass distributions of fragments in the low-energy fission of nuclei from "1"8"7Ir to "2"1"3At have been analysed. This analysis has shown that shell effects in symmetric-mode fragment mass yields from the fission of pre-actinide nuclei could be described if one assumes the existence of two strongly deformed neutron shells in the arising fragments with neutron numbers N_1#approx#52 and N_2#approx#68. A new method has been proposed for quantitatively describing the mass distributions of the symmetric fission mode for pre-actinides with A#approx#180-220. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The double-mode cepheid Y Car has been found to have a variable centre-of-mass velocity. Though the observations did not cover a cycle, an orbital period of about 400-600 days was estimated. Radial-velocity observations of this star have now been continued in order to derive the orbital elements. Observations were made with the photoelectric radial-velocity spectrophotometer at the coude focus of the 1.88-m reflector at Sutherland. The velocity system was standardized by frequent nightly observations of stars in the Mount Wilson catalogue with 'a'-quality radial velocities.

Science.gov (United States)

A finite three-dimensional layer-by-layer photonic crystal with planar defects in a layer is shown to drastically modify the spontaneous emission rate of an embedded dipole. Finite-difference time-domain calculations with one quarter symmetric boundary condition and perfectly matched layer demonstrate the strong enhancement effects induced by the cavity resonance of defect modes and band-edge resonant modes. Simulation shows that the emission spectra are quite different when the position or polarization of the dipole is changed. Moreover, the extraction efficiency is calculated to observe the percentage of light leakage through a substrate.

Energy Technology Data Exchange (ETDEWEB)

The problem of thermal instability of compressible, electrically conducting couple-stress fluids in the presence of a uniform magnetic field is considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the compressibility, couple-stress, and magnetic field postpone the onset of convection. Graphs have been plotted by giving numerical values of the parameters to depict the stability characteristics. The principle of exchange of stabilities is found to be satisfied. The magnetic field introduces oscillatory modes in the system that were non-existent in its absence. The case of overstability is also studied wherein a sufficient condition for the non-existence of overstability is obtained. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A 2D matrix allows a fairly rapid verification of irradiation parameters transferred on computer processing equipment without expanding the dosimetry means to implement. Associated to 'Multicheck and Verisoft' software it will handle some of the regulatory recommendations of the A.F.S.S.A.P.S. for quality control of accelerators and ensure the traceability of testing carried out. (N.C.)

Science.gov (United States)

Effective-index approach is applied for modeling of channel plasmon polaritons (CPPs) propagating in rectangular grooves (trenches) and triangular (V-shaped) grooves in gold, accounting for the main features of CPP guiding and elucidating its underlying physics. The effective indexes of CPP modes along with the corresponding propagation lengths are calculated for different configurations and wavelengths while varying the groove depth. The results obtained allow one to identify the parameter range for realizing the single-mode CPP guiding featuring subwavelength confinement and moderate propagation loss at telecom wavelengths.

International Nuclear Information System (INIS)

Heat transfer augmentation has developed into a major specialty area in heat transfer research and development. A bibliography of world literature on augmentation is presented. The literature is classified into passive augmentation techniques, which require no external power, and active techniques, which do require external power. The fourteen techniques are grouped in terms of their application to the various modes of heat transfer. Mass transfer is included for completeness. Key words are included with each citation for technique/mode identification. The total number of publications cited is 1,967, including 75 surveys of various techniques and 42 papers on performance evaluation of passive techniques. Patents are not included as they will be the subject of a future topical report.

Energy Technology Data Exchange (ETDEWEB)

Gold and silver nanoparticles display extraordinarily large apparent refractive indices near their plasmon resonance (PR) wavelengths. These nanoparticles show good contrast in a narrow spectral band but are poorly resolved at other wavelengths in differential interference contrast (DIC) microscopy. The wavelength dependence of DIC contrast of gold/silver nanoparticles is interpreted in terms of Mie's theory and DIC working principles. We further exploit this wavelength dependence by modifying a DIC microscope to enable simultaneous imaging at two wavelengths. We demonstrate that gold/silver nanoparticles immobilized on the same glass slides through hybridization can be differentiated and imaged separately. High-contrast, video-rate images of living cells can be recorded both with and without illuminating the gold nanoparticle probes, providing definitive probe identification. Dual-wavelength DIC microscopy thus presents a new approach to the simultaneous ...

Energy Technology Data Exchange (ETDEWEB)

A system for real-time neutron radiography of moving objects is described. It comprise a source adapted to generate a continuous uninterrupted series of neutron pulses. Each pulse has a predetermined peak power and duration compatible with the framing times of a real-time video imaging system. A transporter moves an object to be examined to bring sequentially position selected portions of the object in the path of the pulses. Where the object itself has moving components, pulses are sequentially incident on the object. According to any dissimilarities, the object will alter the intensity of the neutrons passing therethrough. In order to record separately the changes in the neutron intensity, for each pulse, an imager is positioned to receive the neutron beam pulses which have been altered by their passage through the object and produce images indicating intensity alterations. A refrigerated beryllium filter can be used to effectively eliminate thermal neutrons from ...

Energy Technology Data Exchange (ETDEWEB)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed Tomography (X-CT) system are used to determine the flow regime, the instantaneous cross-sectional averaged void fraction, and the time averaged void fraction in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements are obtained for gas flow rates form 0.0 to 30.0 l/min. The flow regimes observed by all three measurement systems via image analysis shows that the results agree well with each other. Both the RTNR and the X-CT systems show that the time averaged and cross-sectional averaged void fraction increases with increasing superficial gas velocity. Time and cross-sectional averaged void fractions determined by the RTNR system agree within 4% with those determined by the high speed X-ray CT technique. (orig.).

International Nuclear Information System (INIS)

A real-time neutron radiography system was installed at the neutron radiography facility of Sumitomo Heavy Industries where a sub-compact cyclotron is used as a neutron generator and nominal neutron flux was observed as 1.1 x 10"6 n/cm"2/sec. Preliminary tests were made for various kinds of such components as collimators, scintillators, cameras and lenses and the system was chosen to give the highest quality images. Especially for the scintillator screen, screening tests were carried out for compounds of LiF/ZnS(Ag) and Gd_2O_3/ZnS(Ag) by radiographic film method. The neutron radiography image was converted to fluorescent images by means of the converter and observed by a SIT type TV camera. The video signal was directly displayed on a CRT or after processed with digital image processing devices. The characteristics of this system as for the resultant resolution are presented together with some actual application to dynamical fluid motion of real-time neutron ...

International Nuclear Information System (INIS)

In neutron radiography, as in other forms of NDE, it is sometimes desirable to observe dynamic events. This need has generated increased interest in real-time neutron radiography systems. As in other forms of radiography, a standard method for measuring the image forming capability of real-time systems is necessary in order to compare the various methods and systems used. A technique which has been used extensively in general photography and has been applied in the characterization of several screen-film combinations used in conventional neutron radiography is to determine the imaging system's modulation transfer function (MTF). This gives a graphical representation of the system's spatial resolution capabilities and was therefore chosen as the method for evaluation of the real-time neutron radiography facility at the University of Missouri Research Reactor (MURR). The method used was to image a knife-edge, differentiate the edge gradient to obtain the line spread function (LSF) to ...

Science.gov (United States)

The proceedings of a conference on the development of language capabilities to prepare United States scientists to share in scientific and technological development with Japan include these papers: "Are Japanese Language Programs Reaching Scientists and Engineers?"; "Japanese Language Study for Engineers: High Tech Perspectives"; "Applied Japanese Studies for Science and Engineering at American Universities"; "Training and Certifying Japanese Technical Translators"; "Designing Effective Language Teaching for Professionals"; "Problems in Teaching Technical Japanese"; "Commentary" A Cautious and Deliberate Strategy Is Needed"; "Establishing a Japanese High-Technology Information Company in the United States"; "The Problems of Operating a Technical Translation Company in Japan";"The Japan Information Center of Science and Technology"; "A National Agenda for Japanese Language Training"; "National Language Policies and the 99th Congress"; "Machine Translations: Developments and Prospects"; ...

Energy Technology Data Exchange (ETDEWEB)

By both increasing the optical iris of the video camera and removing the grid in fluoroscopic procedures involved in placement of a Dubbhoff feeding tube, the radiation dose to patients and staff was reduced by five to seven times. An average expected dose to a patient of about 300 mGy per procedure was reduced by two to three times when the grid was removed and by an additional three times when an iris of increased diameter was used. Because Dobbhoff procedures do not involve obtaining a diagnosis, the image degradation was acceptable and did not affect the total exposure times or ability to conduct the procedure. With the grid out, the difference between the mean exposure times of 5.1 minutes in 96 patient studies done with a normal iris opening and 4.0 minutes in 52 studies done with an enlarged iris was not statistically significant. The importance of reducing patient dose is reinforced by the finding that one-third of the patients underwent repeated ...

Energy Technology Data Exchange (ETDEWEB)

The SCILS program investigates and demonstrates concepts of operation for dispersed theater forces C3. The dispersal concept would increase the number of potential targets for nuclear strike, make these targets smaller, more highly mobile and harder to find, and introduce functional redundancy. The SCILS system is a microcomputer-based approach to preserving and enhancing the effectiveness of C3 operation in a dispersed configuration. In this program, the system was implemented for testing for the 9th Infantry Division in coordination with the Army's Distributed Command and Control System. Technical highlights of the system include a distributed, replicated data base, a video map/graphics-oriented Commander's Decision Display System, a packet switched Multi-Media Network that operates with deployed field communication systems, and a Voice/Data Conferencing System that supports remote coordination/briefing in a dispersed configuration. The program ...

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system and a high speed X-ray Computed tomography (X-CT) system are compared for measurement of two-phase flow. Each system is used to determine the flow regime, and the void fraction distribution in a vertical annulus flow channel. A standard optical video system is also used to observe the flow regime. The annulus flow channel is operated as a bubble column and measurements obtained for gas flow rates from 0.0 to 30.01/min. The flow regimes observed by all three measurement systems through image analysis shows that the two-dimensional void fraction distribution can be obtained. The X-CT system is shown to have a superior temporal resolution capable of resolving the void fraction distribution in an (r,#theta#) plane in 33.0 ms. Void fraction distribution for bubbly flow and slug flow is determined.

CERN Multimedia

At the inauguration of the new CMS visitor centre. The CMS experiment inaugurated a new visitor centre at its Cessy site on 14 June. This will allow the thousands of people who come to CERN each year to follow the construction of one the Laboratory's flagship experiments first-hand. CERN receives over 20,000 visitors each year. Until recently, many of them were taken on a guided tour of one of the LEP experiments. With the closure of LEP, however, trips underground are no longer possible, and the Visits' Service has put in place a number of other itineraries (Bulletin 46/2000). Since the CMS detector will be almost entirely constructed in a surface hall, it is now taking a big share of the limelight. The CMS visitor centre has been built on a platform overlooking CMS construction. It contains a set of clear descriptive posters describing the experiment, along with a video projection showing animations and movies about CMS construction. In the coming weeks, a ...

International Nuclear Information System (INIS)

Radiation exposure control is one of the most important aspects in any nuclear facility . It encompasses continuous monitoring of the various areas of the facility to detect any increase in the radiation level and/or the air activity level beyond preset limits and alarm the O and M personnel working in these areas. Detection and measurement of radiation level and the air activity level is carried out by a number of monitors installed in the areas. These monitors include Area Gamma Monitors, Continuous Air Monitors, Pu-In-Air Monitors, Criticality Monitors etc. Traditionally, these measurements are displayed and recorded on a Central Radiation Protection Console(CRPC), which is located in the central control room of the facility. This methodology suffers from the shortcoming that any worker required to enter a work area will have to inquire about the radiation status of the area either from the CRPC or will get to know the same directly from the installed only after entering the area. ...

International Nuclear Information System (INIS)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are investigated. Measurements of flow regime, void ...

Energy Technology Data Exchange (ETDEWEB)

Ion diamagnetic effects on the m=1 (poloidal mode number) and n=1 (toroidal mode number) kinetic internal kink mode are studied numerically by the three-field gyro-reduced-MHD code in the cylindrical coordinates, GRM3F-CY. In the derivation of the gryo-reduced-MHD model including the ion diamagnetic effects, finite gyroradius effects of ions are added to the gyrokinetic Poisson equation (quasi-neutral condition) and the convection term of the conservation law of the ion density. It is found that the long wavelength approximation, ksub(perpendicular) {rho}{sub ti} << 1, where ksub(perpendicular) is the wavenumber perpendicular to the magnetic field and {rho}{sub ti} is the thermal ion gyroradius, fails to reproduce the correct dispersion relation; the formulation valid even for ksub(perpendicular) {rho}{sub ti} >> 1 is necessary. The results of numerical calculation coincide with the theory for ...

Energy Technology Data Exchange (ETDEWEB)

This report describes progress on the Advanced Coal Liquefaction project by the Gulf Research and Development Company's Merriam Laboratory during the months of January through March 1983. The liquefaction behavior of Illinois No. 6 coal beneficiated in various ways was studied in both single-stage recycle (SRC II) and short contact time (SCT) modes of operation. The distillate yield increased as the iron level in the feed slurry increased in both modes of operation. In the SCT mode, the conversion increased at greater depths of cleaning. In the SRC II mode, the distillate yield and conversion were much higher with deep cleaning and add-back of pyrite than with conventional cleaning. Pyrite addition resulted in a significant increase in short contact time conversion of subbituminous Belle Ayr coal in both high and low quality solvents. Solvent quality itself, however, had little effect on ...

Energy Technology Data Exchange (ETDEWEB)

A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower pressures, the emittance apparently ...

Science.gov (United States)

Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of the composite to such an extent that there is virtually very little difference between vacuum impregnation and normal ...

Energy Technology Data Exchange (ETDEWEB)

We investigate the two-body decay modes {rho}{rho}, {pi}{pi}{sup *} (1300) and {sigma}{sigma} of the f{sub 0}(1500), all leading to the four pion decay channel, in a three-state mixing scheme, where the f{sub 0}(1500) is a mixture of the lowest lying scalar glueball with the nearby isoscalar states of the 0{sup ++}Q Q-bar nonet. In the leading order of this scheme, the decay mechanism of the f{sub 0}(1500) proceeds dominantly via its quarkonium components, which can be described in the framework of the {sup 3}P{sub 0} pair creation model. We predict the hierarchy of decay branching ratios B with B({rho}{rho}) {>=} B({pi}{pi}) {>=} B({sigma}{sigma}) > B({pi}{pi}{sup *}), providing a key signature of the proposed mixing scheme in this leading order approach. (authors)

Energy Technology Data Exchange (ETDEWEB)

Microelectronic failure analysis (FA) has been an integral part of the development of state-of-the-art integrated circuits. FA of MicroElectroMechanical Systems (MEMS) is moving from its infancy stage to assume an important role in the successful design, fabrication, performance and reliability analysis for this new technology. In previous work, the authors focused on the application of several techniques developed for integrated circuit analysis to an earlier version of a surface micromachined microengine fabricated at Sandia. Recently, they have identified important new failure modes in binary counters that incorporate a newer design of the microengine, using a subset of integrated circuit failure analysis techniques including optical microscopy, focused ion beam (FIB) techniques, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The primary failure mode they have identified is directly related to visible wear on bearing ...

Energy Technology Data Exchange (ETDEWEB)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

Energy Technology Data Exchange (ETDEWEB)

A Bragg waveguide consisting of multiple dielectric layers with alternating index of refraction becomes an excellent option to form electron accelerating structure powered by high power laser sources. It provides confinement of a synchronous speed-of-light mode with extremely low loss. However, laser field can not be coupled into the structure collinearly with the electron beam. There are three requirements in designing input coupler for a Bragg electron accelerator: side-coupling, selective mode excitation, and high coupling efficiency. We present a side coupling scheme using a distributed grating-assisted coupler to inject the laser power into the waveguide. Side coupling is achieved by a grating with a period on the order of an optical wavelength. The phase matching condition results in resonance coupling thus providing selective mode excitation capability. The coupling efficiency is limited by profile matching between ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the buffeting of a slender, circular, flexible beam-rod in an axial turbulent flow. The principal excitation mechanisms are the turbulent wall pressure fluctuations and the motion-dependent (self-excited) aerodynamic force caused by the beam motion. On the assumption that the turbulent wall pressure fluctuations are independent of the beam motion, a linear forced-vibration model is used to determine the buffeting response of the beam and to investigate the length scale effects of turbulences on the beam buffeting. Transverse buffeting of the beam in an axial turbulent flow depends largely on the ratio of the longitudinal scale of the turbulences to the bending wavelength of the beam and on the ratio of the circumferential scale of the turbulences to the radius of the beam. The spectra and the mean square values of the buffeting displacement of the beam become vanishingly small, both when either of these ratios is very small (<10/sup -2/) and when the latter is ...

Energy Technology Data Exchange (ETDEWEB)

Low-energy focused ion beam (FIB) is a useful tool for shallow doping, gas-assisted etching, and other uses to minimize substrate damage in semiconductor device fabrication. The possibility to form a finely FIB of low energy under 1 keV was suggested in the investigations on the retarding mode in electron optical systems. The abilities of the simplest type of retarding mode FIB column are examined here. The optical properties are calculated for the corresponding model and some images are observed with Ga/sup +/ ion beams <0.3 ..mu..m in diameter for beam energies, 10, 5, and 1 keV, using a retarding mode one-lens FIB system. 1-keV and 100-eV Ga/sup +/ FIB was implanted to Ga/As substrate, and the defects are analyzed by deep-level transient spectroscopy. The defect concentration for 100 eV was < (1)/(5) that for 1000 keV.

International Nuclear Information System (INIS)

The radio, optical, x-ray and gamma-ray nebulae that surround many pulsars are thought to arise from synchrotron and inverse Compton emission. The energy powering this emission as well as the magnetic fields and relativistic particles are supplied by a 'wind' driven by the central object. The inner parts of the wind can be described using the equations of MHD, but these break down in the outer parts, when the density of charge carriers drops below a critical value. This paper reviews the wave properties of the inner part (striped wind), and uses a relativistic two-fluid model (cold electrons and positrons) to re-examine the nonlinear electromagnetic modes that propagate in the outer parts. It is shown that in a radial wind, two solutions exist for circularly polarized electromagnetic modes. At large distances one of them turns into a freely expanding flow containing a vacuum wave, whereas the other decelerates, corresponding to a confined flow.

Energy Technology Data Exchange (ETDEWEB)

The superconducting Tevatron accelerator at Fermi National Accelerator Laboratory (Fermilab) has surpassed twenty years of operation. The Tevatron is still the highest energy particle accelerator in the world and will remain so until the commissioning of the LHC in Europe later this decade. The Tevatron has operated in a Fixed Target mode, accelerating a proton beam into stationary targets/detectors, as well as a Colliding Beam mode, continuously colliding counter rotating beams of protons and antiprotons. Upon completion, the Tevatron cryogenic system became the world's largest helium refrigeration system. In 1993, the Tevatron cryogenic system was given the designation of International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The operational history, experiences and statistics of the Tevatron, with an emphasis on the cryogenic system, is presented. Improvements, upgrades and current ...

CERN Document Server

Consider the flow of a thin layer of non-Newtonian fluid over a solid surface. I model the case of a viscosity that depends nonlinearly on the shear-rate; power law fluids are an important example, but the analysis here is for general nonlinear dependence. The modelling allows for large changes in film thickness provided the changes occur over a large enough lateral length scale. Modifying the surface boundary condition for tangential stress forms an accessible base for the analysis where flow with constant shear is a neutral critical mode, in addition to a mode representing conservation of fluid. Perturbatively removing the modification then constructs a model for the coupled dynamics of the fluid depth and the lateral momentum. For example, the results model the dynamics of gravity currents of non-Newtonian fluids even when the flow is not very slow.

International Nuclear Information System (INIS)

Radiation from an ultrastable 240 GHz solid state source has been injected, through an isolator, into the cavity of the University of California, Santa Barbara millimeter-wave free-electron laser (FEL). High-power FEL emission, normally distributed among many of the cavity's longitudinal modes, is concentrated into the single mode to which the solid state source has been tuned. The linewidth of the FEL emission is 0.5 MHz, consistent with the Fourier transform limit for the 2 #mu#s pulses. This demonstration of frequency-stable, ultranarrow-band FEL emission is a critical milestone on the road to FEL-based pulsed electron paramagnetic resonance spectroscopy.

International Nuclear Information System (INIS)

A reasonable understanding of PWR steam generator corrosion mechanisms such as denting and wastage has been developed, and adequate chemistry control programs defined to obviate the magnitude and effects of these modes of attack. However, relatively unique corrosion attack modes have been encountered at several plants notwithstanding the presence of a reasonable to very good chemistry control program when considered in light of the Steam Generator Owners Group chemistry guidelines. The uniqueness of attack also suggests that parameters not routinely measured or monitored may be playing a significant role. In the authors opinions, the only reasonable method of routinely identifying corrosion accelerating species present in crevices, sludge piles, and deposits in PWR steam generators is by performing detailed chemical return studies during power transients, shutdowns, and long term layups. Although it would be preferable to obtain samples from ...

British Library Electronic Table of Contents (United Kingdom)

Many new technologies and approaches to the provision of comfort inside buildings such as displacement ventilation, mixed-mode strategies, personally controllable (task-ambient) designs, chilled beams as well as some old but recently fashionable ones such as natural ventilation are prompting a rethink of the accepted comfort wisdom. How can a single combination of thermal environmental parameters be deemed unacceptable in a conventional heating ventilation and air-conditioning setting, and yet be regarded as acceptable, or even pleasant, in a naturally ventilated or mixed-mode setting? Why do current comfort standards prescribe static and isothermal conditions for comfort in one building, and dynamic and spatially variable indoor climates for comfort in another? The phenomenon of alliesthe...

British Library Electronic Table of Contents (United Kingdom)

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.

British Library Electronic Table of Contents (United Kingdom)

We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure Formula Not Shown , above which the circular shape of the cross-section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs. Cross-sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 ...

Energy Technology Data Exchange (ETDEWEB)

Recently, we showed (Yu, Phys. Rev. E 58 (1998) 4991) that the widely used simulation code TDA3D, even though a single-frequency code, can be used to determine the power spectrum in the SASE process with excellent approximation in the exponential growth regime. In this paper, we apply this method to the BNL Cornell Wiggler A SASE experiment as an example. When the gain is not very high, there are many modes in the radiation, which seems to make the analytical calculation very difficult. However, we show that the increment of the radiation due to SASE over the spontaneous radiation can be expanded in terms of guided modes with rapid convergence. Thus when the spontaneous radiation is subtracted from the SASE power during the calculation, there is a good agreement between the analytical theory and the numerical simulation.

CERN Document Server

We study perturbations of a Schwarzschild black hole in Chern-Simons modified gravity. We begin by showing that Birkhoff's theorem holds for a wide family of Chern-Simons coupling functions, a scalar field present in the theory that controls the strength of the Chern-Simons correction to the Einstein-Hilbert action. After decomposing the perturbations in spherical harmonics, we study the linearized modified field equations and find that axial and polar modes are coupled, in contrast to general relativity. The divergence of the modified equations leads to the Pontryagin constraint, which forces the vanishing of the Cunningham-Price-Moncrief master function associated with axial modes. We analyze the structure of these equations and find that the appearance of the Pontryagin constraint yields an overconstrained system that does not allow for generic black hole oscillations. We illustrate this situation by studying the case characterized by a ...