Characterization of size, composition and origins of dust in fusion devices. Summary report of the 1. research coordination meeting

International Nuclear Information System (INIS)

Clark, R.E.H.

2009-03-01

Nine experts on dust formation and their physical and behavioural characteristics attended the first Research Coordination Meeting (RCM) on Characterization of Size, Composition and Origins of Dust in Fusion Devices held at IAEA Headquarters on 10-12 December 2008. Participants summarized recent relevant developments related to dust in fusion devices. The specific objectives of the CRP and a detailed work plan were formulated. Discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

Applications of high-speed dust injection to magnetic fusion

International Nuclear Information System (INIS)

Wang, Zhehui; Li, Yangfang

2012-01-01

It is now an established fact that a significant amount of dust is produced in magnetic fusion devices due to plasma-wall interactions. Dust inventory must be controlled, in particular for the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and degrade performance. Safety concerns are due to tritium retention, dust radioactivity, toxicity, and flammability. Performance concerns include high-Z impurities carried by dust to the fusion core that can reduce plasma temperature and may even induce sudden termination of the plasma. We have recognized that dust transport, dust-plasma interactions in magnetic fusion devices can be effectively studied experimentally by injection of dust with known properties into fusion plasmas. Other applications of injected dust include diagnosis of fusion plasmas and edge localized mode (ELM)'s pacing. In diagnostic applications, dust can be regarded as a source of transient neutrals before complete ionization. ELM's pacing is a promising scheme to prevent disruptions and type I ELM's that can cause catastrophic damage to fusion machines. Different implementation schemes are available depending on applications of dust injection. One of the simplest dust injection schemes is through gravitational acceleration of dust in vacuum. Experiments at Los Alamos and Princeton will be described, both of which use piezoelectric shakers to deliver dust to plasma. In Princeton experiments, spherical particles (40 micron) have been dropped in a systematic and reproducible manner using a computer-controlled piezoelectric bending actuator operating at an acoustic (0,2) resonance. The circular actuator was constructed with a 2.5 mm diameter central hole. At resonance (∼ 2 kHz) an applied sinusoidal voltage has been used to control the flux of particles exiting the hole. A simple screw throttle located ∼1mm above the hole has been used to set the magnitude of the flux achieved for a given voltage

Characterization of Size, Composition and Origins of Dust in Fusion Devices. Summary Report of the Second Research Coordination Meeting

International Nuclear Information System (INIS)

Braams, B.J.; Skinner, C.H.

2010-11-01

Eleven experts on processes of dust in fusion experiments met for the 2nd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Characterization of size, composition and origins of dust in fusion devices' held at IAEA Headquarters 21-23 June 2010. Participants summarized their studies on dust in fusion experiments and reviewed progress made since the first RCM. Gaps in knowledge were identified and a plan of work for the remainder of the CRP was developed. Presentations, discussions and recommendations of the RCM are summarized in this report. Eleven experts on processes of dust in fusion experiments met for the 2nd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Characterization of size, composition and origins of dust in fusion devices' held at IAEA Headquarters 21-23 June 2010. Participants summarized their studies on dust in fusion experiments and reviewed progress made since the first RCM. Gaps in knowledge were identified and a plan of work for the remainder of the CRP was developed. Presentations, discussions and recommendations of the RCM are summarized in this report. (author)

Fugitive dust control experiments using soil fixatives on vehicle traffic surfaces

International Nuclear Information System (INIS)

Winberg, M.R.; Wixom, V.E.

1992-08-01

This report presents the results of engineering scale dust control experiments using soil fixative for contamination control during handling of transuranic waste. These experiments focused on controlling dust during retrieval operations of buried waste where waste and soil are intimately mixed. Sources of dust generation during retrieval operations include digging, dumping, and vehicle traffic. Because contaminants are expected to attach to soil particles and move with the generated dust, control of the dust spread may be the key to contamination control. Dust control techniques examined in these experiments include the use of soil fixatives to control generation of fugitive dusts during vehicle traffic operations. Previous experiments conducted in FY 1990 included testing of the soil fixative, ENTAC. These experiments showed that ENTAC was effective in controlling dust generation but had several undesirable properties such as slow cure times and clogged the pumps and application nozzles. Therefore, other products would have to be evaluated to find a suitable candidate. As a result, two soil fixatives were tested in these present experiments, COHEREX-PM, an asphalt emulsion product manufactured by Witco Corporation and FLAMBINDER, a calcium lignosulfonate product manufactured by Flambeau Corporation. The results of the experiments include product performance and recommended application methods for application in a field deployable contamination control unit to be built in FY 1993

Evaluate fundamental approaches to longwall dust control. Phase III report

Energy Technology Data Exchange (ETDEWEB)

Babbitt, C.; Bartlett, P.; Kelly, J.; Ludlow, J.; Mangolds, A.; Rajan, S.; Ruggieri, S.; Varga, E.

1984-03-31

The overall objective of the contract is to evaluate the effectiveness of available dust control technology for double-drum shearer longwall sections in a coordinated, systematic program at a few longwall test sections and to make the results available to the entire coal mining industry. This program is investigating nine different dust control techniques. These nine subprograms encompass a broad range of dust control measures ranging from administrative controls to new hardware. They span not only presently employed methods but also those recently adopted in the United States and those proposed for the future. This report documents the Phase III effort on each of the subprograms. For clarity, the report is divided in sections by subprogram as follows: Section 2, Subprogram A - passive barriers/spray air movers for dust control; Section 3, Subprogram B - practical aspects of deep cutting; Section 4, Subprogram C - stage loader dust control; Section 5, Subprogram D - longwall automation technology; Section 6, Subprogram E - longwall application of ventilation curtains; Section 7, Subprogram F - reversed drum rotation; Section 8, Subprogram G - reduction of shield generated dust; Section 9, Subprogram H - air canopies for longwalls; and Section 10, Subprogram I - mining practices. 43 figures, 11 tables.

Controlling fugitive dust emissions in material handling operations

Energy Technology Data Exchange (ETDEWEB)

Tooker, G E

1992-05-01

The primary mechanism of fugitive dust generation in bulk material handling transfer operations is by dispersion of dust in turbulent air induced to flow with falling or projected material streams. This paper returns to basic theories of particle dynamics and fluid mechanics to quantify the dust generating mechanism by rational analysis. Calculations involving fluid mechanisms are made easier by the availability of the personal computer and the many math manipulating programs. Rational analysis is much more cost effective when estimating collection air volumes to control fugitive emissions; especially in enclosed material handling transfers transporting large volumes of dusty material. Example calculations, using a typical enclosed conveyor-to-conveyor transfer operation are presented to illustrate and highlight the key parameters that determine the magnitude of induced air flow that must be controlled. The methods presented in this paper for estimating collection air volumes apply only enclosed material handling transfers, exhausted to a dust collector. Since some assistance to the control of dust emissions must be given by the material handling transfer chute design, a discussion of good transfer chute design practice is presented. 4 refs., 2 figs., 2 tabs.

Laboratory Studies on the Charging of Dust Grains in a Plasma

Science.gov (United States)

Xu, Wenjun

1993-01-01

The charging of dust grains by the surrounding plasma is studied in a dusty plasma device (DPD) (Xu, W., B. Song, R. L. Merlino, and N. D'Angelo, Rev. Sci. Instrum., 63, 5266, 1992). The dusty plasma device consists of a rotating-drum dust dispersal device used in conjunction with an existing Q-machine, to produce extended, steady state, magnetized plasma columns. The dust density in the dust chamber is controlled by the drum rotation speed. The device is capable of generating a dusty plasma in which as much as about 90% of the negative charge is attached to the dust grains of 1-10mu m size. Measurements of the dust parameter eta, the percentage of negative charge on free electrons in the dusty plasma, are presented. The dust parameter eta is found to depend on the rotational speed of the dust chamber, plasma density and the type and size of different dust. The dust parameter eta is calculated from a pair of Langmuir curves taken with and without dust under the same conditions. The operation of the dust chamber as described above has been confirmed by the agreement between the measurements of eta and the direct mechanical measurements consisting of weighing dust samples collected within the rotation dust chamber, at different rotation rates. By varying the ratio d/lambda_ {rm D} between the intergrain distance and the plasma Debye length, the effects predicted by Goertz and Ip (Goertz, C. K., and W-H. Ip, Geophys. Res. Lett., 11, 349, 1984), and subsequently reanalyzed in a more general fashion by Whipple et al. (Whipple, E. C., T. G. Northrop, and D. A. Mendis, J. Geophys. Rev., 90, 7405, 1985), as "isolated" dust grains become "closely packed" grains, have been demonstrated experimentally (Xu, W., N. D'Angelo, and R. L. Merlino, J. Geophys. Rev., 98, 7843, 1993). Similar results are presented and compared for two types of dust, kaolin and Al_2O _3, which have been studied in the experiment.

Analysis of the three-dimensional trajectories of dusts observed with a stereoscopic fast framing camera in the Large Helical Device

Energy Technology Data Exchange (ETDEWEB)

Shoji, M., E-mail: shoji@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan); Masuzaki, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan); Tanaka, Y. [Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan); Pigarov, A.Yu.; Smirnov, R.D. [University of California at San Diego, La Jolla, CA 92093 (United States); Kawamura, G.; Uesugi, Y.; Yamada, H. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Gifu (Japan)

2015-08-15

The three-dimensional trajectories of dusts have been observed with two stereoscopic fast framing cameras installed in upper and outer viewports in the Large Helical Device (LHD). It shows that the dust trajectories locate in divertor legs and an ergodic layer around the main plasma confinement region. While it is found that most of the dusts approximately move along the magnetic field lines with acceleration, there are some dusts which have sharply curved trajectories crossing over the magnetic field lines. A dust transport simulation code was modified to investigate the dust trajectories in fully three dimensional geometries such as LHD plasmas. It can explain the general trend of most of observed dust trajectories by the effect of the plasma flow in the peripheral plasma. However, the behavior of the some dusts with sharply curved trajectories is not consistent with the simulations.

House dust mite control measures for asthma

DEFF Research Database (Denmark)

Gøtzsche, Peter C.; Johansen, Helle Krogh

2008-01-01

BACKGROUND: The major allergen in house dust comes from mites. Chemical, physical and combined methods of reducing mite allergen levels are intended to reduce asthma symptoms in people who are sensitive to house dust mites. OBJECTIVES: To assess the effects of reducing exposure to house dust mite...... antigens in the homes of people with mite-sensitive asthma. SEARCH STRATEGY: PubMed and The Cochrane Library (last searches Nov 2007), reference lists. SELECTION CRITERIA: Randomised trials of mite control measures vs placebo or no treatment in people with asthma known to be sensitive to house dust mites......), the standardised mean difference was 0.00 (95% confidence interval (CI) -0.10 to 0.10). There were no statistically significant differences either in number of patients improved (relative risk 1.01, 95% CI 0.80 to 1.27), asthma symptom scores (standardised mean difference -0.04, 95% CI -0.15 to 0...

Efficiency of inert mineral dusts in the control of corn weevil

Directory of Open Access Journals (Sweden)

Carlos F. Jairoce

2016-02-01

Full Text Available ABSTRACT Corn weevil (Sitophilus zeamais may cause great losses in the crop and in stored corn grains. This insect is controlled with the use of chemical insecticides, which may cause serious damage to human health. One alternative of control is the use of inert dusts. The objective of this study was to evaluate the efficiency of inert dusts in the control of S. zeamais under laboratory conditions. The experiment was conducted in 2014, in a completely randomized design, and the treatments consisted of basalt dust with three different granulometries (A, B and C and diatomaceous earth, each of which at the doses of 2 and 4 kg t-1 and a control (no application. Each treatment had four replicates, and the sample unit consisted of 20 g of corn grains infected with 10 adults of S. zeamais kept in temperature-controlled chamber at 25 °C, 70% RH and photophase of 12 h. The dust efficiency was calculated using the equation of Abbott. The mortality rate was higher with the use of diatomaceous earth, reaching 100% after 5 days of exposure and the percentage of control for basalt dusts, 29 days after treatment, was above 80%.

Test plan for FY-91 dust control studies

International Nuclear Information System (INIS)

Winberg, M.R.

1991-03-01

This test plan defines basic test procedures for testing commercially available vendor products as soil fixatives and dust suppression agents to determine their capability to control fugitive dust generation during transuranic waste retrieval and handling operations. A description of the test apparatus and methods are provided in this test plan. This test plan defines the sampling procedures, controls, and analytical methods for the samples collected. Data management is discussed, as well as quality assurance and safety requirements for the study. 6 refs., 5 figs

Characterization of Size, Composition and Origins of Dust in Fusion Devices. Summary Report of the Third Research Coordination Meeting

International Nuclear Information System (INIS)

Braams, B.J.

2013-02-01

Twelve experts on processes of dust in fusion experiments met at IAEA Headquarters 30 November - 02 December 2011 for the 3rd Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on ''Characterization of size, composition and origins of dust in fusion devices.'' Participants reviewed their work done in the course of the CRP and the current state of knowledge, and they made plans for a dust database and a final CRP report. Presentations, discussions and recommendations of the RCM are summarized here. (author)

Modeled effectiveness of ventilation with contaminant control devices on indoor air quality in a swine farrowing facility.

Science.gov (United States)

Anthony, T Renée; Altmaier, Ralph; Park, Jae Hong; Peters, Thomas M

2014-01-01

Because adverse health effects experienced by swine farm workers in concentrated animal feeding operations (CAFOs) have been associated with exposure to dust and gases, efforts to reduce exposures are warranted, particularly in winter seasons when exposures increase due to decreased ventilation. Simulation of air quality and operating costs for ventilating swine CAFO, including treating and recirculating air through a farrowing room, was performed using mass and energy balance equations over a 90-day winter season. System operation required controlling heater operation to achieve room temperatures optimal to ensure animal health (20 to 22.5 °C). Five air pollution control devices, four room ventilation rates, and five recirculation patterns were examined. Inhalable dust concentrations were easily reduced using standard industrial air pollution control devices, including a cyclone, filtration, and electrostatic precipitator. Operating ventilation systems at 0.94 m3 s(-1) (2000 cfm) with 75 to 100% recirculation of treated air from cyclone, electrostatic precipitator, and shaker dust filtration system achieves adequate particle control with operating costs under $1.00 per pig produced ($0.22 to 0.54), although carbon dioxide (CO2) concentrations approach 2000 ppm using in-room ventilated gas fired heaters. In no simulation were CO2 concentrations below industry recommended concentrations (1540 ppm), but alternative heating devices could reduce CO2 to acceptable concentrations. While this investigation does not represent all production swine farrowing barns, which differ in characteristics including room dimensions and swine occupancy, the simulation model and ventilation optimization methods can be applied to other production sites. This work shows that ventilation may be a cost-effective control option in the swine industry to reduce exposures.

Tungsten dust remobilization under steady-state and transient plasma conditions

Directory of Open Access Journals (Sweden)

S. Ratynskaia

2017-08-01

Full Text Available Remobilization is one of the most prominent unresolved fusion dust-relevant issues, strongly related to the lifetime of dust in plasma-wetted regions, the survivability of dust on hot plasma-facing surfaces and the formation of dust accumulation sites. A systematic cross-machine study has been initiated to investigate the remobilization of tungsten micron-size dust from tungsten surfaces implementing a newly developed technique based on controlled pre-adhesion by gas dynamics methods. It has been utilized in a number of devices and has provided new insights on remobilization under steady-state and transient conditions. The experiments are interpreted with contact mechanics theory and heat conduction models.

In-vessel dust and tritium control strategy in ITER

Energy Technology Data Exchange (ETDEWEB)

Shimada, M., E-mail: michiya.shimada@iter.org [ITER Organization, Route de Vinon-sur-Verdon, 13115 St. Paul-lez-Durance (France); Pitts, R.A.; Ciattaglia, S.; Carpentier, S.; Choi, C.H.; Dell Orco, G.; Hirai, T.; Kukushkin, A.; Lisgo, S.; Palmer, J.; Shu, W.; Veshchev, E. [ITER Organization, Route de Vinon-sur-Verdon, 13115 St. Paul-lez-Durance (France)

2013-07-15

A baseline strategy for dust and tritium-inventory control and recovery in ITER has been established and preparations are underway for its implementation. Limits on dust and tritium-inventory are an integral part of the ITER safety case and are fixed at 1 kg for tritium, 1000 kg for mobilisable dust and 11 kg (beryllium)/76 kg (tungsten) for dust on hot surfaces. Maximum average T-retention rates of ∼1 g/shot are estimated for baseline inductive operation at Q{sub DT} = 10, suggesting that the in-vessel T-retention could reach the administrative limit of 640 g in as little as ∼2 months of operation. Baking is expected to remove a significant fraction of the T co-deposited on the divertor targets. Despite large uncertainties, dust quantities are expected to remain well below safety limits over the divertor cassette lifetime. In situ aspiration during divertor cassette exchange is foreseen as the main dust removal technique.

Process control device

International Nuclear Information System (INIS)

Hayashi, Toshifumi; Kobayashi, Hiroshi.

1994-01-01

A process control device comprises a memory device for memorizing a plant operation target, a plant state or a state of equipments related with each other as control data, a read-only memory device for storing programs, a plant instrumentation control device or other process control devices, an input/output device for performing input/output with an operator, and a processing device which conducts processing in accordance with the program and sends a control demand or a display demand to the input/output device. The program reads out control data relative to a predetermined operation target, compares and verify them with actual values to read out control data to be a practice premise condition which is further to be a practice premise condition if necessary, thereby automatically controlling the plant or requiring or displaying input. Practice presuming conditions for the operation target can be examined succesively in accordance with the program without constituting complicated logical figures and AND/OR graphs. (N.H.)

Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasmas.

Science.gov (United States)

Choudhary, Mangilal; Mukherjee, S; Bandyopadhyay, P

2016-05-01

A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current glow discharge. These dust particles are found to get trapped in an electrostatic potential well, which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self-excited dust acoustic waves, and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust particle, and some of the preliminary experimental results are presented.

Predistortion control device and method, assembly including a predistortion control device

NARCIS (Netherlands)

Kokkeler, Andre B.J.

2003-01-01

A predistortion control device (1). The device has a first predistortion control input connectable to a power amplifier output (21); a second predistortion control input (11) connectable to a signal contact of a predistortion device; and a predistortion control output (12) connectable to a control

Review of fugitive dust control for uranium mill tailings

International Nuclear Information System (INIS)

Li, C.T.; Elmore, M.R.; Hartley, J.N.

1983-01-01

An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques

Review of fugitive dust control for uranium mill tailings

Energy Technology Data Exchange (ETDEWEB)

Li, C.T.; Elmore, M.R.; Hartley, J.N.

1983-01-01

An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques.

Control rod position control device

International Nuclear Information System (INIS)

Ubukata, Shinji.

1997-01-01

The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

Foam property tests to evaluate the potential for longwall shield dust control.

Science.gov (United States)

Reed, W R; Beck, T W; Zheng, Y; Klima, S; Driscoll, J

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration's lower coal mine respirable dust standard of 1.5 mg/m 3 . Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control.

Dust in flowing magnetized plasma

International Nuclear Information System (INIS)

Pandey, Birendra P.; Samarian, Alex A.; Vladimirov, Sergey V.

2009-01-01

Plasma flows occur in almost every laboratory device and interactions of flowing plasmas with near-wall impurities and/or dust significantly affects the efficiency and lifetime of such devices. The charged dust inside the magnetized flowing plasma moves primarily under the influence of the plasma drag and electric forces. Here, the charge on the dust, plasma potential, and plasma density are calculated self-consistently. The electrons are assumed non-Boltzmannian and the effect of electron magnetization and electron-atom collisions on the dust charge is calculated in a self-consistent fashion. For various plasma magnetization parameters viz. the ratio of the electron and ion cyclotron frequencies to their respective collision frequencies, plasma-atom and ionization frequencies, the evolution of the plasma potential and density in the flow region is investigated. The variation of the dust charge profile is shown to be a sensitive function of plasma parameters. (author)

Dust coma of Halley comet: measurements with the dust counter and mass analyzer (DUSMA)

International Nuclear Information System (INIS)

Simpson, J.A.; Sagdeev, R.Z.; Tuzzolino, A.J.; AN SSSR, Moscow. Inst. Kosmicheskikh Issledovanij)

1986-01-01

The paper represents a preliminary report on measurements of spatial and temporal distribution of mass and flows of dust particles coming from comet nucleus performed by means of devices constructed on the new principle of detecting comet dust specks. The device has a high time resolution (∼ 4 μs) in the wide range of mass and dust flows. On the base of a preliminary analysis the following conclusions are drawn: dust coma in quiet state (''Vega-2'') as well as at the presence of considerable emissions (''Vega-1'') manifests the presence of important short-term out-bursts having by time a quasi-periodic structure. Integral mass spectra show flows intensity growth with the decrease of measured mass (which contradicts some theoretical models). Flow levels lie approximately in the region previously determined by ground observations. The coma is extremely dynamic both in space and in time which proves the complex structure of regions of dust emission from the nucleus

Coupling the Mars Dust and Water Cycles: Investigating the Role of Clouds in Controlling the Vertical Distribution of Dust During N. H. Summer

Science.gov (United States)

Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Wilson, R. J.

2014-01-01

The dust cycle is critically important for the current climate of Mars. The radiative effects of dust impact the thermal and dynamical state of the atmosphere (Gierasch and Goody, 1968; Haberle et al., 1982; Zurek et al., 1992). Although dust is present in the Martian atmosphere throughout the year, the level of dustiness varies with season. The atmosphere is generally the dustiest during northern fall and winter and the least dusty during northern spring and summer (Smith, 2004). Dust particles are lifted into the atmosphere by dust storms that range in size from meters to thousands of kilometers across (Cantor et al., 2001). During some years, regional storms combine to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by as much as 40 K (Smith et al., 2002). Key recent observations of the vertical distribution of dust indicate that elevated layers of dust exist in the tropics and sub-tropics throughout much of the year (Heavens et al., 2011). These observations have brought particular focus on the processes that control the vertical distribution of dust in the Martian atmosphere. The goal of this work is to further our understanding of how clouds in particular control the vertical distribution of dust, particularly during N. H. spring and summer

Simulation of impurity transport in the peripheral plasma due to the emission of dust in long pulse discharges on the Large Helical Device

Directory of Open Access Journals (Sweden)

M. Shoji

2017-08-01

Full Text Available Two different plasma termination processes by dust emission were observed in long pulse discharges in the Large Helical Device. One is a plasma termination caused by large amounts of carbon dust released from a lower divertor region. The other is termination caused by stainless steel (iron dust emission from the surface of a helical coil can. The effect of the dust emission on the sustainment of the long pulse discharges are investigated using a three-dimensional edge plasma transport code (EMC3-EIRENE coupled with a dust transport code (DUSTT. The simulation shows that the plasma is more influenced by the iron dust emission from the helical coil can than by the carbon dust emission from the divertor region. The simulation revealed that the plasma flow in divertor legs is quite effective for preventing dust from terminating the long pulse discharges.

Evaluation of Surface Modification as a Lunar Dust Mitigation Strategy for Thermal Control Surfaces

Science.gov (United States)

Gaier, James R.; Waters, Deborah L.; Misconin, Robert M.; Banks, Bruce A.; Crowder, Mark

2011-01-01

Three surface treatments were evaluated for their ability to lower the adhesion between lunar simulant dust and AZ93, AlFEP, and AgFEP thermal control surfaces under simulated lunar conditions. Samples were dusted in situ and exposed to a standardized puff of nitrogen gas. Thermal performance before dusting, after dusting, and after part of the dust was removed by the puff of gas, were compared to perform the assessment. None of the surface treatments was found to significantly affect the adhesion of lunar simulants to AZ93 thermal control paint. Oxygen ion beam texturing also did not lower the adhesion of lunar simulant dust to AlFEP or AgFEP. But a workfunction matching coating and a proprietary Ball Aerospace surface treatment were both found to significantly lower the adhesion of lunar simulants to AlFEP and AgFEP. Based on these results, it is recommended that all these two techniques be further explored as dust mitigation coatings for AlFEP and AgFEP thermal control surfaces.

Creation of Wood Dust during Wood Processing: Size Analysis, Dust Separation, and Occupational Health

Directory of Open Access Journals (Sweden)

Eva Mračková

2015-11-01

Full Text Available Mechanical separators and fabric filters are being used to remove airborne fine particles generated during the processing and handling of wood. Such particles might have a harmful effect on employee health, not only in small- but also in large-scale wood processing facilities. The amount of wood dust and its dispersion conditions vary according to geometric boundary conditions. Thus, the dispersion conditions could be changed by changing the linear size of the particles. Moreover, the smaller the particles are, the more harmful they can be. It is necessary to become familiar with properties, from a health point of view, of wood dust generated from processing. Wood dust has to be sucked away from the processing area. The fractional separation efficiency of wood dust can be improved using exhaust and filtering devices. Filtration efficiency depends on moisture content, particle size, and device performance. Because of the carcinogenicity of wood dust, the concentration of wood dust in air has to be monitored regularly. Based on the results hereof, a conclusion can be made that both mechanical separators of types SEA and SEB as well as the fabric filters with FINET PES 1 textile are suitable for the separation of wet saw dust from all types of wooden waste produced within the process.

Effect of energetic electrons on dust charging in hot cathode filament discharge

Science.gov (United States)

Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.

2011-03-01

The effect of energetic electrons on dust charging for different types of dust is studied in hydrogen plasma. The hydrogen plasma is produced by hot cathode filament discharge method in a dusty plasma device. A full line cusped magnetic field cage is used to confine the plasma elements. To study the plasma parameters for various discharge conditions, a cylindrical Langmuir probe having 0.15 mm diameter and 10.0 mm length is used. An electronically controlled dust dropper is used to drop the dust particles into the plasma. For different discharge conditions, the dust current is measured using a Faraday cup connected to an electrometer. The effect of secondary emission as well as discharge voltage on charging of dust grains in hydrogen plasma is studied with different dust.

Effect of energetic electrons on dust charging in hot cathode filament discharge

International Nuclear Information System (INIS)

Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.

2011-01-01

The effect of energetic electrons on dust charging for different types of dust is studied in hydrogen plasma. The hydrogen plasma is produced by hot cathode filament discharge method in a dusty plasma device. A full line cusped magnetic field cage is used to confine the plasma elements. To study the plasma parameters for various discharge conditions, a cylindrical Langmuir probe having 0.15 mm diameter and 10.0 mm length is used. An electronically controlled dust dropper is used to drop the dust particles into the plasma. For different discharge conditions, the dust current is measured using a Faraday cup connected to an electrometer. The effect of secondary emission as well as discharge voltage on charging of dust grains in hydrogen plasma is studied with different dust.

Dust control for draglines

Energy Technology Data Exchange (ETDEWEB)

Grad, P.

2009-09-15

Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

Open-air sprays for capturing and controlling airborne float coal dust on longwall faces

Science.gov (United States)

Beck, T.W.; Seaman, C.E.; Shahan, M.R.; Mischler, S.E.

2018-01-01

Float dust deposits in coal mine return airways pose a risk in the event of a methane ignition. Controlling airborne dust prior to deposition in the return would make current rock dusting practices more effective and reduce the risk of coal-dust-fueled explosions. The goal of this U.S. National Institute for Occupational Safety and Health study is to determine the potential of open-air water sprays to reduce concentrations of airborne float coal dust, smaller than 75 µm in diameter, in longwall face airstreams. This study evaluated unconfined water sprays in a featureless tunnel ventilated at a typical longwall face velocity of 3.6 m/s (700 fpm). Experiments were conducted for two nozzle orientations and two water pressures for hollow cone, full cone, flat fan, air atomizing and hydraulic atomizing spray nozzles. Gravimetric samples show that airborne float dust removal efficiencies averaged 19.6 percent for all sprays under all conditions. The results indicate that the preferred spray nozzle should be operated at high fluid pressures to produce smaller droplets and move more air. These findings agree with past respirable dust control research, providing guidance on spray selection and spray array design in ongoing efforts to control airborne float dust over the entire longwall ventilated opening. PMID:29348700

Open-air sprays for capturing and controlling airborne float coal dust on longwall faces.

Science.gov (United States)

Beck, T W; Seaman, C E; Shahan, M R; Mischler, S E

2018-01-01

Float dust deposits in coal mine return airways pose a risk in the event of a methane ignition. Controlling airborne dust prior to deposition in the return would make current rock dusting practices more effective and reduce the risk of coal-dust-fueled explosions. The goal of this U.S. National Institute for Occupational Safety and Health study is to determine the potential of open-air water sprays to reduce concentrations of airborne float coal dust, smaller than 75 µm in diameter, in longwall face airstreams. This study evaluated unconfined water sprays in a featureless tunnel ventilated at a typical longwall face velocity of 3.6 m/s (700 fpm). Experiments were conducted for two nozzle orientations and two water pressures for hollow cone, full cone, flat fan, air atomizing and hydraulic atomizing spray nozzles. Gravimetric samples show that airborne float dust removal efficiencies averaged 19.6 percent for all sprays under all conditions. The results indicate that the preferred spray nozzle should be operated at high fluid pressures to produce smaller droplets and move more air. These findings agree with past respirable dust control research, providing guidance on spray selection and spray array design in ongoing efforts to control airborne float dust over the entire longwall ventilated opening.

Dust control products at Hagerman National Wildlife Refuge, Texas: environmental safety and performance

Science.gov (United States)

Kunz, Bethany K.; Little, Edward E.

2015-01-01

Controlling fugitive dust while protecting natural resources is a challenge faced by all managers of unpaved roads. Unfortunately, road managers choosing between dust control products often have little objective environmental information to aid their decisions. To address this information gap, the U.S. Geological Survey and the U.S. Fish and Wildlife Service collaborated on a field test of three dust control products with the objectives of (a) evaluating product performance under real-world conditions, (b) verifying the environmental safety of products identified as practically nontoxic in laboratory tests, and (c) testing the feasibility of several environmental monitoring techniques for use in dust control tests. In cooperation with refuge staff and product vendors, three products (one magnesium chloride plus binder, one cellulose, and one synthetic fluid plus binder) were applied in July 2012 to replicated road sections at the Hagerman National Wildlife Refuge in Texas. These sections were monitored periodically for 12 months after application. Product performance was assessed by mobile-mounted particulate-matter meters measuring production of fugitive dust and by observations of road conditions. Environmental safety was evaluated through on-site biological observations and leaching tests with samples of treated aggregate. All products reduced dust and improved surface condition during those 12 months. Planned environmental measurements were not always compatible with day-to-day refuge management actions; this incompatibility highlighted the need for flexible biological monitoring plans. As one of the first field tests of dust suppressants that explicitly incorporated biological endpoints, this effort provides valuable information for improving field tests and for developing laboratory or semifield alternatives.

Control in indoor radon decay products by air treatment devices

International Nuclear Information System (INIS)

Hinds, W.C.; Rudnick, S.N.; Maher, E.F.; First, M.W.

1983-01-01

An evaluation of the efficacy of household air cleaning devices as a means to control radon decay products in existing buildings is presented. Previous research on air cleaning methods for airborne radon decay products has been directed primarily to the control of radon decay products in mines and has only limited application to control in residences where dust concentration, air change rate, and humidity are lower than in mines. Results show that room size air cleaners can achieve substantial reductions in working levels in residences. Reductions observed at air infiltration rates of 0.52 air changes per hour ranged from 58 to 89%. Although the two air cleaners tested produced the greatest reductions, the low cost, simplicity, and other benefits of air circulating fans, particularly the ceiling fan, appear to make them most suitable for residences

DeviceNet-based device-level control in SSRF

CERN Document Server

Leng Yong Bin; Lu Cheng Meng; Miao Hai Feng; Liu Song Qiang; Shen Guo Bao

2002-01-01

The control system of Shanghai Synchrotron Radiation Facility is an EPICS-based distributed system. One of the key techniques to construct the system is the device-level control. The author describes the design and implementation of the DeviceNet-based device controller. A prototype of the device controller was tested in the experiments of magnet power supply and the result showed a precision of 3 x 10 sup - sup 5

Integrated control rod monitoring device

International Nuclear Information System (INIS)

Saito, Katsuhiro

1997-01-01

The present invention provides a device in which an entire control rod driving time measuring device and a control rod position support device in a reactor building and a central control chamber are integrated systematically to save hardwares such as a signal input/output device and signal cables between boards. Namely, (1) functions of the entire control rod driving time measuring device for monitoring control rods which control the reactor power and a control rod position indication device are integrated into one identical system. Then, the entire devices can be made compact by the integration of the functions. (2) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated in a central operation board and a board in the site. Then, the place for the installation of them can be used in common in any of the cases. (3) The functions of the entire control rod driving time measuring device and the control rod position indication device are integrated to one identical system to save hardware to be used. Then, signal input/output devices and drift branching panel boards in the site and the central operation board can be saved, and cables for connecting both of the boards is no more necessary. (I.S.)

Control of dust hazards in mines

Energy Technology Data Exchange (ETDEWEB)

Sukhanov, V V

1981-09-01

This paper analyzes health hazards associated with air pollution by respirable coal dust which causes pneumoconioses. The following directions in pneumoconioses prevention are discussed: improved protective systems (e.g. respirators), mining schemes optimized from a health hazards point of view, correct determination of the maximum permissible level of respirable dusts, reducing working time. Safety regulations in the USSR on the critical amount of coal dust in the miner respiratory system are insufficient as the 20 g limit is too high and does not guarantee safety. Using regression analysis influence of the factors which cause pneumoconioses is analyzed. This influence is described by an equation which considers the following factors: number of shifts associated with contact of a miner with coal dusts, dust concentration in mine air, amount of air with coal dust being respirated, miner's age, years as miner, coal rank. It is stated that use of the proposed equation (derived by computer calculations) permits the safe working time to be correctly determined considering all factors which cause pneumoconioses.

Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic Atomization

Science.gov (United States)

Okawa, Hirokazu; Nishi, Kentaro; Shindo, Dai; Kawamura, Youhei

2012-07-01

The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 µm), green tuff (6 µm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without.

[Protecting Safety During Dust Fires and Dust Explosions - The Example of the Formosa Fun Coast Water Park Accident].

Science.gov (United States)

Hsieh, Ming-Hong; Wu, Jia-Wun; Li, Ya-Cing; Tang, Jia-Suei; Hsieh, Chun-Chien

2016-02-01

This paper will explore the fire and explosion characteristics of cornstarch powder as well as strategies for protecting the safety of people who are involved a dust fire or dust explosion. We discuss the 5 elements of dust explosions and conduct tests to analyze the fire and explosion characteristics of differently colored powders (yellow, golden yellow, pink, purple, orange and green). The results show that, while all of the tested powders were difficult to ignite, low moisture content was associated with significantly greater risks of ignition and flame spread. We found the auto-ignition temperature (AIT) of air-borne cornstarch powder to be between 385°C and 405°C, with yellow-colored cornstarch powder showing the highest AIT and pink-colored cornstarch powder showing the lowest AIT. The volume resistivity of all powder samples was approximately 108 Ω.m, indicating that they were nonconductive. Lighters and cigarettes are effective ignition sources, as their lit temperatures are higher than the AIT of cornstarch powder. In order to better protect the safety of individuals at venues where cornstarch powder is released, explosion control measures such as explosion containment facilities, vents, and explosion suppression and isolation devices should be installed. Furthermore, employees that work at these venues should be better trained in explosion prevention and control measures. We hope this article is a reminder to the public to recognize the fire and explosion characteristics of flammable powders as well as the preventive and control measures for dust explosions.

30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

Science.gov (United States)

2010-07-01

... District Manager and posting. 71.301 Section 71.301 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... plan; approval by District Manager and posting. (a) The District Manager will approve respirable dust control plans on a mine-by-mine basis. When approving respirable dust control plans, the District Manager...

Discharge power dependence of carbon dust flux in a divertor simulator

International Nuclear Information System (INIS)

Nishiyama, Katsushi; Morita, Yasuhiko; Uchida, Giichiro; Yamashita, Daisuke; Kamataki, Kunihiro; Seo, Hyunwoong; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu; Ashikawa, Naoko; Masuzaki, Suguru; Nishimura, Kiyohiko; Sagara, Akio; Bornholdt, Sven; Kersten, Holger

2013-01-01

In fusion devices, dust particles are generated due to plasma–wall interactions and may cause safety or operational problems. Therefore it is necessary to clarify the generation and transport mechanisms of dust particles. Here we have measured energy influx from H 2 plasmas toward a graphite target using a calorimetric probe and compared the results with the dust flux toward a dust collecting substrate set on the reactor wall. The dust flux decreases with increasing the energy influx. For the higher discharge power, the more number of dust particles tend to redeposit onto the graphite target due to the higher ion drag force and hence the dust flux toward the reactor wall becomes smaller. The results show that dust inventory depends strongly on energy influx to graphite divertor plates in fusion devices

A smart dust biosensor powered by kinesin motors.

Science.gov (United States)

Fischer, Thorsten; Agarwal, Ashutosh; Hess, Henry

2009-03-01

Biosensors can be miniaturized by either injecting smaller volumes into micro- and nanofluidic devices or immersing increasingly sophisticated particles known as 'smart dust' into the sample. The term 'smart dust' originally referred to cubic-millimetre wireless semiconducting sensor devices that could invisibly monitor the environment in buildings and public spaces, but later it also came to include functional micrometre-sized porous silicon particles used to monitor yet smaller environments. The principal challenge in designing smart dust biosensors is integrating transport functions with energy supply into the device. Here, we report a hybrid microdevice that is powered by ATP and relies on antibody-functionalized microtubules and kinesin motors to transport the target analyte into a detection region. The transport step replaces the wash step in traditional double-antibody sandwich assays. Owing to their small size and autonomous function, we envision that large numbers of such smart dust biosensors could be inserted into organisms or distributed into the environment for remote sensing.

Reactor control device

International Nuclear Information System (INIS)

Fukami, Haruo; Morimoto, Yoshinori.

1981-01-01

Purpose: To operate a reactor always with safety operation while eliminating the danger of tripping. Constitution: In a reactor control device adapted to detect the process variants of a reactor, control a control rod drive controlling system based on the detected signal to thereby control the driving the control rods, control the reactor power and control the electric power generated from an electric generator by the output from the reactor, detection means is provided for the detection of the electric power from said electric generator, and a compensation device is provided for outputting control rod driving compensation signals to the control rod driving controlling system in accordance with the amount of variation in the detected value. (Seki, T.)

Note: Electrostatic detection of stainless steel dust particles for fusion applications

Energy Technology Data Exchange (ETDEWEB)

Landy, P. [Mechanical and Aerospace Engineering Department, Cornell University, Ithaca, New York 14853 (United States); Skinner, C. H.; Schneider, H. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-03-15

Dust accumulation inside next-step fusion devices poses a significant safety concern and dust diagnostics will be needed to assure safe operations. An electrostatic dust detection device has been successfully demonstrated in the National Spherical Torus Experiment, Tore Supra, and the Large Helical Device, and the detector's response to carbon particles was previously characterized in laboratory experiments. This paper presents laboratory results showing that detection of stainless steel particles at levels as low as several μg/cm{sup 2} is also possible.

[Comparative studies of personal and steady-state sampling for determining dust exposure in different job groups].

Science.gov (United States)

Cherneva, P; Lukanova, R

1994-01-01

The variability of the dust concentration in time and space, as well as the change of worker's place during the working process, define the necessity of introducing personal sampling in the hygiene control practice. However, the laboratory equipment with personal devices is still not sufficient. The aim of this work is to assess the dust exposure of the basic professional groups from the ore- and coal production in Bulgaria by personal sampling in comparative studies of the static ambient sampling used up to now. 63 full-shift investigations of the dust factor were performed on professional groups of miners of the polymetal and coal pits by static ambient devices-[Hygitest production] and personal [from firms "Casella", "Strolein" and "Gilian"] devices, after standardized methods. The results are data processed-by means of logarithmic normal distribution of the relation of the respirable dust concentrations, determined personally and by static ambient sampling. The limits of variation of this correlation are from 0.5 to 4.1 at average geometric value -0.95 and standard geometric deviation-1.8 i.e. both types of sampling are intersubstitutional for the examined groups and sites, as in the underground ores the professional risk of respirable dust is underestimated up to 4 times at static ambient sampling.

Generic device controller for accelerator control systems

International Nuclear Information System (INIS)

Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

1987-01-01

A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described

Dust control in Belgian coal mines. Position at the beginning of 1975

Energy Technology Data Exchange (ETDEWEB)

Preat, B; Vanstraelen, M

1975-01-01

A general view is given of dust control in Belgian coal mines at the beginning of 1975. The statistical data received from the mines are presented in tabular form. The length and the output of coal faces treated by the classical methods of pre-spraying of the wall, wet cutting, water infusion and wet pneumatic picks are given separately; in some cases two or more of these techniques are used together on the same coalface. The number of rock headings in which different methods of dust control are used is also given.

Mimicking Martian dust: An in-vacuum dust deposition system for testing the ultraviolet sensors on the Curiosity rover

International Nuclear Information System (INIS)

Sobrado, J. M.; Martín-Soler, J.; Martín-Gago, J. A.

2015-01-01

We have designed and developed an in-vacuum dust deposition system specifically conceived to simulate and study the effect of accumulation of Martian dust on the electronic instruments of scientific planetary exploration missions. We have used this device to characterize the dust effect on the UV sensor of the Rover Environmental Monitoring Station in the Mars science Laboratory mission of NASA in similar conditions to those found on Mars surface. The UV sensor includes six photodiodes for measuring the radiation in all UV wavelengths (direct incidence and reflected); it is placed on the body of Curiosity rover and it is severely affected by the dust deposited on it. Our experimental setup can help to estimate the duration of reliable reading of this instrument during operation. We have used an analogous of the Martian dust in chemical composition (magnetic species), color, and density, which has been characterized by X-ray spectroscopy. To ensure a Brownian motion of the dust during its fall and a homogeneous coverage on the instrumentation, the operating conditions of the vacuum vessel, determined by partial pressures and temperature, have to be modified to account for the different gravities of Mars with respect to Earth. We propose that our designed device and operational protocol can be of interest to test optoelectronic instrumentation affected by the opacity of dust, as can be the degradation of UV photodiodes in planetary exploration

Mimicking Martian dust: An in-vacuum dust deposition system for testing the ultraviolet sensors on the Curiosity rover

Energy Technology Data Exchange (ETDEWEB)

Sobrado, J. M., E-mail: sobradovj@inta.es; Martín-Soler, J. [Centro de Astrobiología (CAB), INTA-CSIC, Torrejón de Ardoz, 28850 Madrid (Spain); Martín-Gago, J. A. [Centro de Astrobiología (CAB), INTA-CSIC, Torrejón de Ardoz, 28850 Madrid (Spain); Instituto de Ciencias de Materiales de Madrid (ICMM–CSIC), Cantoblanco, 28049 Madrid (Spain)

2015-10-15

We have designed and developed an in-vacuum dust deposition system specifically conceived to simulate and study the effect of accumulation of Martian dust on the electronic instruments of scientific planetary exploration missions. We have used this device to characterize the dust effect on the UV sensor of the Rover Environmental Monitoring Station in the Mars science Laboratory mission of NASA in similar conditions to those found on Mars surface. The UV sensor includes six photodiodes for measuring the radiation in all UV wavelengths (direct incidence and reflected); it is placed on the body of Curiosity rover and it is severely affected by the dust deposited on it. Our experimental setup can help to estimate the duration of reliable reading of this instrument during operation. We have used an analogous of the Martian dust in chemical composition (magnetic species), color, and density, which has been characterized by X-ray spectroscopy. To ensure a Brownian motion of the dust during its fall and a homogeneous coverage on the instrumentation, the operating conditions of the vacuum vessel, determined by partial pressures and temperature, have to be modified to account for the different gravities of Mars with respect to Earth. We propose that our designed device and operational protocol can be of interest to test optoelectronic instrumentation affected by the opacity of dust, as can be the degradation of UV photodiodes in planetary exploration.

Control rod selecting and driving device

International Nuclear Information System (INIS)

Isobe, Hideo.

1981-01-01

Purpose: To simultaneously drive a predetermined number of control rods in a predetermined mode by the control of addresses for predetermined number of control rods and read or write of driving codified data to and from the memory by way of a memory controller. Constitution: The system comprises a control rod information selection device for selecting predetermined control rods from a plurality of control rods disposed in a reactor and outputting information for driving them in a predetermined mode, a control rod information output device for codifying the information outputted from the above device and outputting the addresses to the predetermined control rods and driving mode coded data, and a driving device for driving said predetermined control rods in a predetermined mode in accordance with the codified data outputted from the above device, said control rod infromation output device comprising a memory device capable of storing a predetermined number of the codified data and a memory control device for storing the predetermined number of data into the above memory device at a predetermined timing while successively outputting the thus stored predetermined number of data at a predetermined timing. (Seki, T.)

Control rod drive hydraulic device

International Nuclear Information System (INIS)

Takekawa, Toru.

1994-01-01

The device of the present invention can reliably prevent a possible erroneous withdrawal of control rod driving mechanism when the pressure of a coolant line is increased by isolation operation of hydraulic control units upon periodical inspection for a BWR type reactor. That is, a coolant line is connected to the downstream of a hydraulic supply device. The coolant line is connected to a hydraulic control unit. A coolant hydraulic detection device and a pressure setting device are disposed to the coolant line. A closing signal line and a returning signal line are disposed, which connect the hydraulic supply device and a flow rate control valve for the hydraulic setting device. In the device of the present invention, even if pressure of supplied coolants is elevated due to isolation of hydraulic control units, the elevation of the hydraulic pressure can be prevented. Accordingly, reliability upon periodical reactor inspection can be improved. Further, the facility is simplified and the installation to an existent facility is easy. (I.S.)

The control and prevention of dust explosions

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

Papers presented discussed: explosion characteristics and hybrid mixtures explosion characteristics and influencing factors, propagation of dust explosions in ducts, prevention of dust explosions, desensitization, explosion-proof type of construction, explosion pressure relief, optical flame barriers, slide-valves for explosion protection, Ventex explosion barrier valves, grinding and mixing plants, spray driers, dust explosions in silos, and explosion-proof bucket elevators. One paper has been abstracted separately.

Effects of grain dust on lungs prior to and following dust remediation.

Science.gov (United States)

Pahwa, Punam; Dosman, James A; McDuffie, Helen H

2008-12-01

To determine longitudinal estimates of pulmonary function decline in Canadian grain elevator workers before and after dust control by analyzing data collected from five regions of Canada over 15 years. Declines in forced expired volume in one second and forced vital capacity before and after dust control were estimated by using a generalized estimating equations approach. For grain workers who were in the grain industry for 20 or more years both before and after dust control: the mean annual loss of forced expired volume in one second was greatest among current smoking grain workers followed by ex-smokers and nonsmokers, respectively. Similar results were obtained for forced vital capacity. Grain dust control was effective in reducing decline in the lung function measurements among grain workers in all smoking and exposure categories.

Control rod control device

International Nuclear Information System (INIS)

Seiji, Takehiko; Obara, Kohei; Yanagihashi, Kazumi

1998-01-01

The present invention provides a device suitable for switching of electric motors for driving each of control rods in a nuclear reactor. Namely, in a control rod controlling device, a plurality of previously allotted electric motors connected in parallel as groups, and electric motors of any selected group are driven. In this case, a voltage of not driving predetermined selected electric motors is at first applied. In this state an electric current supplied to the circuit of predetermined electric motors is detected. Whether integration or failure of a power source and the circuit of the predetermined electric motors are normal or not is judged by the detected electric current supplied. After they are judged normal, the electric motors are driven by a regular voltage. With such procedures, whether the selected circuit is normal or not can be accurately confirmed previously. Since the electric motors are not driven just at the selected time, the control rods are not operated erroneously. (I.S.)

30 CFR 74.6 - Quality control.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Quality control. 74.6 Section 74.6 Mineral... of the CMDPSU will be maintained in production through adequate quality control procedures, MSHA and... DUST SAMPLING DEVICES Approval Requirements for Coal Mine Dust Personal Sampler Unit § 74.6 Quality...

Complex plasma experimental device – A test bed for studying dust ...

Indian Academy of Sciences (India)

2016-11-03

Nov 3, 2016 ... gas, for inserting the electrode system and carrying out their electrical .... dust particles is found to be sensitive to the distribution of dust particles on the .... which an approximately constant voltage drop across the electrodes is ...

Dust in the wind: Soiling of solar devices : Is there a Holy Grail solution? (Conference Presentation)

Science.gov (United States)

Kazmerski, Lawrence; Costa, Suellen C.; Machado, Marcelo; Diniz, Antonia Sonia A. C.

2016-09-01

Soiling, the sedimentation of particulate matter (on the size scale of 1/10 the diameter of a human hair) on the exposed surfaces of solar collectors, is a growing area of concern for solar-system performance, reliability, maintenance, and cost. In the case of photovoltaics (PV), the condition of this first-surface of interaction of the incident photons is critical for ensuring that the maximum-possible light reaches the conversion devices. This paper begins with a more than seven-decade historical look at the research invested into this problem, highlighting the motivation and milestones; the researchers and the progress. The current growing terrestrial markets for solar have brought a new focus on soiling and dust issues. That is because many of these new markets in the solar-rich geographic regions of our world are ironically also in the most dust-rich and soiling-prone ones as well. This paper continues to provide an overview of the status of current research efforts toward understanding the basic soiling mechanisms, the relationships to the PV technology approaches, the geographical differences (highlighting Brasil, India, and the MENA region) in the severity of the problem, the dust physics and chemistry—all relating to the current and future mitigation approaches. Included are some fundamental microscale through nanoscale examinations at how individual dust particles adhere to module glass surfaces—as well as how the particles might stick to each other under certain environmental conditions. These observations are used to show how fundamental science may lead to the macroscale engineering solutions of these soiling problems. This presentation is designed to both overview the soiling area and highlight some of the current and future research directions, speculate on short-term approaches preventing solar showstoppers, and speculate on some "holy-grail" schemes that might lead to the final solutions.

Beryllium dust generation resulting from plasma bombardment

International Nuclear Information System (INIS)

Doerner, R.; Mays, C.

1997-01-01

The beryllium dust resulting from erosion of beryllium samples subjected to plasma bombardment has been measured in PISCES-B. Loose surface dust was found to be uniformly distributed throughout the device and accounts for 3% of the eroded material. A size distribution measurement of the loose surface dust shows an increasing number of particles with decreasing diameter. Beryllium coatings on surfaces with a line of sight view of the target interaction region account for an additional 33% of the eroded beryllium material. Flaking of these surface layers is observed and is thought to play a significant role in dust generation inside the vacuum vessel. (orig.)

Experimental demonstration and visual observation of dust trapping in an electron storage ring

Directory of Open Access Journals (Sweden)

Yasunori Tanimoto

2009-11-01

Full Text Available Sudden decreases in the beam lifetime, which are attributed to the dust trappings, sometimes occur at the electron storage ring Photon Factory Advanced Ring (PF-AR. Since these dust events cause difficulties in user operations, we have been carefully observing this phenomenon for many years. Our observations indicated that the dust trappings could be caused by electric discharges in vacuum ducts. In order to demonstrate this hypothesis experimentally, we designed a new vacuum device that intentionally generates electric discharges and installed it in PF-AR. Using this device, we could repeatedly induce sudden decreases in the beam lifetime because of the generated electric discharge. We also detected decreases in the beam lifetime caused by mechanical movement of the electrodes in the device. Moreover, we could visually observe the dust trapping phenomenon; the trapped dust particle was observed by two video cameras and appeared as a luminous body that resembled a shooting star. This was the first direct observation of a luminous dust particle trapped by the electron beam.

Comparison of a direct-reading device to gravimetric methods for evaluating organic dust aerosols in an enclosed swine production environment.

Science.gov (United States)

Taylor, C D; Reynolds, S J

2001-01-01

The production of livestock in enclosed facilities has become an accepted practice, driven by the need for increased efficiency. Exposure to organic dusts, containing various bioactive components, has been identified an important risk factor for the high rate of lung disease found among workers in these environments. Assessment of organic dust exposure requires technical skills and instrumentation not readily available to most agricultural enterprises. Development of a simple, cost-effective method for measuring organic dust levels would be useful in evaluating and controlling exposures in these environments. The objective of this study was to evaluate the usefulness of the direct reading MIE PDM-3 Miniram for estimating organic dust concentrations in enclosed swine production facilities. Responses from the MIE PDM-3 Miniram were compared to gravimetric methods for total and inhalable dust. Total dust determinations were conducted in accordance with the National Institute for Occupational Safety and Health (NIOSH) method 0500. Inhalable particulate mass (IPM) sampling was conducted using SKC brand IOM (Institute of Occupational Medicine) sampling cassettes, which meet the American Conference of Governmental Industrial Hygienists ACGIH criteria for inhalable dust sampling. This study design also allowed for the comparison of traditional total dust method to the IPM method, in collecting organic dusts in an agricultural setting. Fifteen sets of side-by-side samples (Miniram, total dust, and IPM) were collected over a period of six months in a swine confinement building. There were statistically significant differences in the results provided by the three sampling methods. Measurements for inhalable dust exceeded those for total dust in eleven of fifteen samples. The Miniram time-weighted average (TWA) response to the organic dust was always the lower of the three methods. A high degree of correlation was found among all three methods. The Miniram performed well under

Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process

Energy Technology Data Exchange (ETDEWEB)

Swain, Basudev, E-mail: Swain@iae.re.kr [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Yongin-Si 449-863 (Korea, Republic of); Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Yongin-Si 449-863 (Korea, Republic of); Lee, Kun-Jae [Department of Energy Engineering, Dankook University, Cheonan 330-714 (Korea, Republic of)

2015-07-15

Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga{sub 0.97}N{sub 0.9}O{sub 0.09} is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga{sub 0.97}N{sub 0.9}O{sub 0.09} of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4 M HCl, 100 °C and pulp density of 100 kg/m{sup 3,} respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. - Highlights: • Waste MOCVD dust is treated through mechanochemical leaching. • GaN is hardly leached, and converted to NaGaO{sub 2} through ball milling and annealing. • Process for gallium recovery from waste MOCVD dust has been developed. • Thermal analysis and phase properties of GaN to Ga{sub 2}O{sub 3} and GaN to NaGaO{sub 2} is revealed. • Solid-state chemistry involved in this process is reported.

Valorization of GaN based metal-organic chemical vapor deposition dust a semiconductor power device industry waste through mechanochemical oxidation and leaching: A sustainable green process.

Science.gov (United States)

Swain, Basudev; Mishra, Chinmayee; Lee, Chan Gi; Park, Kyung-Soo; Lee, Kun-Jae

2015-07-01

Dust generated during metal organic vapor deposition (MOCVD) process of GaN based semiconductor power device industry contains significant amounts of gallium and indium. These semiconductor power device industry wastes contain gallium as GaN and Ga0.97N0.9O0.09 is a concern for the environment which can add value through recycling. In the present study, this waste is recycled through mechanochemical oxidation and leaching. For quantitative recovery of gallium, two different mechanochemical oxidation leaching process flow sheets are proposed. In one process, first the Ga0.97N0.9O0.09 of the MOCVD dust is leached at the optimum condition. Subsequently, the leach residue is mechanochemically treated, followed by oxidative annealing and finally re-leached. In the second process, the MOCVD waste dust is mechanochemically treated, followed by oxidative annealing and finally leached. Both of these treatment processes are competitive with each other, appropriate for gallium leaching and treatment of the waste MOCVD dust. Without mechanochemical oxidation, 40.11 and 1.86 w/w% of gallium and Indium are leached using 4M HCl, 100°C and pulp density of 100 kg/m(3,) respectively. After mechanochemical oxidation, both these processes achieved 90 w/w% of gallium and 1.86 w/w% of indium leaching at their optimum condition. Copyright © 2015 Elsevier Inc. All rights reserved.

Electrodynamic Dust Shield Demonstrator

Science.gov (United States)

Stankie, Charles G.

2013-01-01

The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

'Nuisance Dust' - a Case for Recalibration?

Science.gov (United States)

Datson, Hugh; Marker, Brian

2013-04-01

time). 'Custom and practice' acceptance criteria for dust samples obtained by mass or soiling techniques have been developed and are widely applied even though they were not necessarily calibrated thoroughly and have not been reviewed recently. Furthermore, as sampling techniques have evolved, criteria developed for one method have been adapted for another. Criteria and limit values have sometimes been based on an insufficient knowledge of sampler characteristics. Ideally, limit values should be calibrated for the locality to take differences in dust density and visibility into account. Work is needed on the definition of criteria and limit values, and sampling practices for coarse dust fractions, followed by discussion of good practices for securing effective monitoring that is proportionate and fit for purpose. With social changes and the evolution of environmental controls since the 1960s, the public perception of 'nuisance dust' has changed and needs to be addressed by reviewing existing thresholds in relation to the range of monitoring devices currently in use.

30 CFR 71.100 - Respirable dust standard.

Science.gov (United States)

2010-07-01

... concentration of respirable dust in the mine atmosphere during each shift to which each miner in the active... shall be measured with an approved sampling device and expressed in terms of an equivalent concentration determined in accordance with § 71.206 (Approved sampling devices; equivalent concentrations). ...

Development of an Electrostatic Dust Detector for use in a Tokamak Reactor

International Nuclear Information System (INIS)

Bader, A.; Skinner, C.H.; Roquemore, A.L.; Langish, S.

2003-01-01

Initial results from a novel device to detect dust particles settling on remote surfaces are presented. Dust particle inventories are a concern in next-step fusion devices. The increase in duty cycle will lead to a scale-up in the amount of particles generated by plasma material interactions. These particles will be chemically and radiologically hazardous and it will be important to establish that the in-vessel particle inventory is within regulatory limits. The detection device consists of two interlocking combs of closely spaced conductive traces on a Teflon circuit board. When a DC bias is applied impinging dust creates a transient short circuit between the traces. The increase in bias current generates a signal pulse that is counted by standard nuclear counting electronics. We present data on the response of the device in air and vacuum to carbon particles

The effects of a newsletter on bedding control on house dust mite allergen concentrations in childcare centers in Korea

Directory of Open Access Journals (Sweden)

Jeonghoon Kim

2015-08-01

Full Text Available Objectives Bedding in childcare centers (CCCs can hold house dust mite (HDM allergens. This study examined whether HDM allergen levels can be reduced through the distribution of an educational newsletter on bedding control to parents of CCC children in Korea. Methods All 38 CCCs were measured for Der 1 (sum of Der f 1 and Der p 1 concentrations on classroom floors and bedding before the intervention. Educational newsletters on children’s bedding control were sent to 21 CCCs by mail, and teachers were asked to distribute the newsletters to the parents of the children (intervention group. The remaining 17 CCCs were not sent newsletters (control group. The measurement of Der 1 concentrations in 38 CCCs was repeated after the intervention. Dust samples were collected with a vacuum cleaner and analyzed using enzyme-linked immunosorbent assay methods. Results The Der 1 concentrations on the bedding were significantly higher than those on the floors in 38 CCCs at baseline (p<0.05. Although changes of the Der 1 concentrations for the control group (n=17 were not significant, Der 1 concentrations for the intervention group (n=21 decreased significantly from 2077.9 ng/g dust to 963.5 ng/g dust on the floors and from 3683.9 ng/g dust to 610.4 ng/g dust on bedding (p<0.05. Conclusions The distribution of educational newsletters on bedding control to parents may be an effective means of controlling HDMs in CCCs.

Control system of fuel transporting device

International Nuclear Information System (INIS)

Yokota, Minoru.

1981-01-01

Purpose: To effectively avoid an obstacle in a fuel transporting device by reading the outputs of absolute position detectors mounted on movable trucks, controlling the movements of the trucks, and thereby smoothly and accurately positioning the fuel transporting device at predetermined position and providing a contact detector thereat. Method: The outputs from absolute position detectors which are mounted on a longitudinally movable truck and a laterally movable truck are input to an input/output control circuit. The input/output control circuit serves to compare, the position a fuel transporting device is to be moved to, with the present position on the basis of said input detection signal and a command signal from an operator console, to calculate the amount of movement to be driven, to produce an operation signal therefor to a control panel, and to drive and control the drive motors which are respectively mounted on the trucks for the fuel transfer device. On the other hand, in case that the transfer device comes into contact with an obstacle, the contact detector will immediately operate to produce a stop command through the control panel to the transporting device, and avoid a collision with the obstacle. (Yoshino, Y.)

Observations of dusty plasmas with magnetized dust grains

Science.gov (United States)

Luo, Q.-Z.; D'Angelo, N.

2000-11-01

We report a newly observed phenomenon in a dusty plasma device of the \\mbox{Q-machine} type. At low plasma densities the time required by the plasma to return to its no-dust conditions, after the dust dispenser is turned off, can be as long as many tens of seconds or longer. A tentative interpretation of this observation in terms of magnetized dust grains is advanced. It appears that an important loss mechanism of fine dust grains is by ion drag along the magnetic field lines. The effect of ion drag is somewhat counteracted by the -µ∇B force present when the magnetic field has a mirror geometry.

Investigation of Dusts Effect and Negative Ion in DC Plasmas by Electric Probes

Science.gov (United States)

Oh, Hye Taek; Kang, Inje; Bae, Min-Keun; Park, Insun; Lee, Seunghwa; Jeong, Seojin; Chung, Kyu-Sun

2017-10-01

Dust is typically negatively charged by electron attachment whose thermal velocities are fast compared to that of the heavier ions. The negatively charged particles can play a role of negative ions which affect the quasi-neutrality of background plasma. To investigate effect of metal dusts and negative ion on plasma and materials, metal dusts are injected into background Ar plasma which is generated by tungsten filament using dust dispenser on Cubical Plasma Device (CPD). The CPD has following conditions: size =24x24x24cm3, plasma source =DC filament plasma (ne 1x10x1010, Te 2eV), background gas =Ar, dusts =tungsten powder (diameter 1.89micron). The dust dispenser is developed to quantitate of metal dust by ultrasonic transducer. Electronegative plasmas are generated by adding O2 + Ar plasma to compare negative ion and dust effect. A few grams of micron-sized dusts are placed in the dust dispenser which is located at the upper side of the Cubical Plasma Device. The falling particles by dust dispenser are mainly charged up by the collection of the background plasma. The change in parameters due to negative ion production are characterized by measuring the floating and plasma potential, electron temperature and negative ion density using electric probes.

Diagnostics of mobile dust in scrape-off layer plasmas

International Nuclear Information System (INIS)

Ratynskaia, S; Castaldo, C; Bergsaaker, H; Rudakov, D

2011-01-01

Dust production and accumulation pose serious safety and operational implications for the next generation fusion devices. Mobile dust particles can result in core plasma contamination with impurities, and those with high velocities can significantly contribute to the wall erosion. Diagnostics for monitoring dust in tokamaks during plasma discharges are hence important as they can provide information on dust velocity and size, and-in some cases-on dust composition. Such measurements are also valuable as an input for theoretical models of dust dynamics in scrape-off layer plasmas. Existing in situ dust diagnostics, focusing on the range of dust parameters they can detect, are reviewed. Particular attention is paid to the diagnostics which allow us to detect tails of the dust velocity and size distributions, e.g. small and very fast particles. Some of the techniques discussed have been adopted from space-related research and have been shown to be feasible and useful for tokamak applications as well.

Fluid circulation control device

International Nuclear Information System (INIS)

Benard, Henri; Henocque, Jean.

1982-01-01

Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

Electrostatic Dust Detection and Removal for ITER

International Nuclear Information System (INIS)

C.H. Skinner; A. Campos; H. Kugel; J. Leisure; A.L. Roquemore; S. Wagner

2008-01-01

We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 (micro)m spacing is biased to 30-50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm 2 with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations

A device for the hydraulic control of nuclear reactor control rods

International Nuclear Information System (INIS)

Frisch, Erling; Frisch, D.R.; Andrews, H.N.

1974-01-01

A device for driving and locking the control rods of a nuclear reactor. This device comprises a hydraulic driving piston mounted in a cylinder provided with a construction for absorbing shocks. The piston is provided, at is extremity, with a locking device adapted to engage a stationary lock, it being possible to control the latter for freeing said piston locking device; with such an arrangement, the control rod is normally maintained in position, and it can be freed only by a positive signal. Moreover, the control rod movements are slowed down, so as to prevent the gripping device from being damaged. This device can be used in the nuclear industry [fr

Methods for decreasing dust emission in the mining chemistry industry

Energy Technology Data Exchange (ETDEWEB)

Gal' perin, V I

1981-01-01

Examination is made of the problems concerning the protection of the atmosphere from pollution caused by dust emission from phosphate enterprises. Presentation is made of the results of tests and industrial assimilation of devices, designed for an increase in the effectiveness of dust catching systems.

Monitoring device for withdrawing control rods

International Nuclear Information System (INIS)

Higashigawa, Yuichi.

1985-01-01

Purpose: To improve the sensitivity and the responsivity to an equivalent extent to those in the case where local power range monitors are densely arranged near each of the control rods, with no actual but pseudo increase of the number of local power range monitors. Constitution: The monitor arrangement is patterned by utilizing the symmetricity of the reactor core and stored in a monitor designating device. The symmetricity of control rods to be selected and withdrawn by an operator is judged by a control rod symmetry monitoring device, while the symmetricity of the withdrawn control rods is judged by a control rod withdrawal state monitoring device. Then, only when both of the devices judge the symmetricity, the control rods are subjected to gang driving by the control rod drive mechanisms. In this way, monitoring at a high sensitivity and responsivity is enabled with no increase for the number of monitors. (Yoshino, Y.)

Inactivation of dust mites, dust mite allergen, and mold from carpet.

Science.gov (United States)

Ong, Kee-Hean; Lewis, Roger D; Dixit, Anupma; MacDonald, Maureen; Yang, Mingan; Qian, Zhengmin

2014-01-01

Carpet is known to be a reservoir for biological contaminants, such as dust mites, dust mite allergen, and mold, if it is not kept clean. The accumulation of these contaminants in carpet might trigger allergies or asthma symptoms in both children and adults. The purpose of this study is to compare methods for removal of dust mites, dust mite allergens, and mold from carpet. Carpets were artificially worn to simulate 1 to 2 years of wear in a four-person household. The worn carpets were inoculated together with a common indoor mold (Cladosporium species) and house dust mites and incubated for 6 weeks to allow time for dust mite growth on the carpet. The carpets were randomly assigned to one of the four treatment groups. Available treatment regimens for controlling carpet contaminants were evaluated through a literature review and experimentation. Four moderately low-hazard, nondestructive methods were selected as treatments: vacuuming, steam-vapor, Neem oil (a natural tree extract), and benzalkonium chloride (a quaternary ammonium compound). Steam vapor treatment demonstrated the greatest dust mite population reduction (p 0.05) for both physical and chemical methods. The steam-vapor treatment effectively killed dust mites and denatured dust mite allergen in the laboratory environment.

Dust removal in radio-frequency plasmas by a traveling potential modulation

International Nuclear Information System (INIS)

Li Yangfang; Jiang Ke; Thomas, Hubertus M.; Morfill, Gregor E.

2010-01-01

The dust contamination in plasma deposition processes plays a crucial role in the quality and the yield of the products. To improve the quality and the yield of plasma processing, a favorable way is to remove the dust particles actively from the plasma reactors.Our recent experiments in the striped electrode device show that a traveling plasma modulation allows for a systematic particle removal independent of the reactor size. Besides the rf powered electrode, the striped electrode device includes a segmented electrode that consists of 100 electrically insulated narrow stripes. A traveling potential profile is produced by the modulation of the voltage signals applied on the stripes. The dust particles are trapped in the potential wells and transported with the traveling of the potential profile.The particle-in-cell (PIC) simulation on the potential above the segmented electrode indicates that the traveling potential profile can be realized either by applying low-frequency (0.1-10 Hz) voltage signals with a fixed phase shift between adjacent stripes or high-frequency (10 kHz a circumflex AS 100 MHz) signals with the amplitudes modulated by a low-frequency envelope. The transportation of the dust particles is simulated with a two-dimensional molecular dynamics (MD) code with the potential profile obtained from the PIC simulation. The MD results reproduce the experimental observations successfully.This technology allows for an active removal of the contaminating particles in processing plasmas and it is independent of the reactor size. The removal velocity is controllable by adjusting the parameters for the modulation.

A Three-Year Course of House Dust Mite Sublingual Immunotherapy Appears Effective in Controlling the Symptoms of Allergic Rhinitis.

Science.gov (United States)

Novakova, Silviya M; Novakova, Plamena I; Yakovliev, Plamen H; Staevska, Maria T; Mateva, Nonka G; Dimcheva, Teodora D; Peichev, Jivko L

2018-05-01

Background Allergic rhinitis is the most common allergic disorder. Although the management of the disease is successful in many patients, based on guidelines, some of them remain with symptoms uncontrolled with pharmacotherapy. Presently, there is no substantiated information on the control of allergic rhinitis in patients who underwent sublingual immunotherapy. Objective The purpose of this prospective follow-up study was to assess the control of allergic rhinitis in adults after a three-year course of house dust mite sublingual immunotherapy. Methods This prospective real-life study was designed to include adults with moderate to severe allergic rhinitis sensitized to house dust mite who underwent a three-year course of sublingual immunotherapy. Control of symptoms was assessed by Rhinitis Control Assessment Test (RCAT) after three years of house dust mite sublingual immunotherapy. Additionally, patients assessed their symptoms by utilizing a visual analog scale. Results A total number of 86 consecutively enrolled patients (46 (53.49%) men; mean age 26.10 years (SD = 5.85)) with moderate to severe allergic rhinitis and clinically relevant sensitization to house dust mite were evaluated. When assessed by RCAT on the third year, 74 (86.05%) had well-controlled symptoms and 20 (27.03%) of them were completely controlled. A significant reduction in visual analog scale scores-from 7.52 cm at baseline to 2.31 cm-was established ( P house dust mite sublingual immunotherapy appears effective in controlling the symptoms of allergic rhinitis.

DIII-D dust particulate characterization (June 1998 Vent)

International Nuclear Information System (INIS)

Carmack, W.J.

1999-01-01

Dust is a key component of fusion power device accident source term. Understanding the amount of dust expected in fusion power devices and its physical and chemical characteristics is needed to verify assumptions currently used in safety analyses. An important part of this safety research and development work is to characterize dust from existing experimental tokamaks. In this report, the authors present the collection, data analysis methods used, and the characterization of dust particulate collected from various locations inside the General Atomics DIII-D vacuum vessel following the June 1998 vent. The collected particulate was analyzed at the Idaho National Engineering and Environmental Laboratory (INEEL). Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Choice of collection technique is important because the sampling method used can bias the particle size distribution collected. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Seventeen samples were collected including plasma facing surfaces in lower, upper, and horizontal locations, surfaces behind floor tiles, surfaces behind divert or tiles, and surfaces behind ceiling tiles. The results of the analysis are presented

Design, Implementation & Assessment of Local Exhaust Ventilation System and dust collectors for crushing unit

Directory of Open Access Journals (Sweden)

Farshid Ghorbani shahna

2015-09-01

Full Text Available Background & objective: Industrial ventilation systems and dust collectors are effective solutions to reduce particulate emissions in the workplace and environmental in mineral processes. In this study, Local Exhaust Ventilation System and dust collectors for control of emitted silica, coke, silicon carbide dusts from crushing unit was designed and evaluated. Methods: : Local Exhaust ventilation system based on standards and guides was designed and implemented after field study of the processes and sources of air pollutants. A set comprised of the four parallel cyclones (Stairmand model and a new design of the scrubber had been used for dust control. After set-up of systems, its effectiveness in reducing the exposure of workers in the workshops and dust collecting were assessed. Results: Test results were significant differences between the concentration of particles in both on and off the ventilation system revealed (P <0.05. The system has been implemented as means of personal exposure to pollutants and environmental emissions were reduced 93.01% and 64.64%, respectively. Also, alone and integrated collection efficiency of cyclone and scrubber, were 94.2%, 59.05% and 97.4%, respectively. The results show good agreement with the values of the parameters ventilation system was designed. Conclusion: Implementation of integrated dust collectors is a good option in industries that have the financial and technical constraints to improve change processes and devices. This method with attainment to health and environmental standards not only can be resolve of the pollution problems, but also will be economically justified of such projects with reduction of depreciation expense and dust recycling.

Control method for prosthetic devices

Science.gov (United States)

Bozeman, Richard J., Jr. (Inventor)

1995-01-01

A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

Remote controlled transport device

International Nuclear Information System (INIS)

Nakahira, Masataka; Oka, Kiyoshi; Ito, Akira; Tada, Eisuke; Sato, Masaki

1998-01-01

The present invention provides a device for transporting equipments for maintenance and parts between a maintenance port and a facility for maintenance by remote control in a radioactive material handling facility such as a nuclear power plant. Namely, a power supply bus bar is disposed along a transferring path in order to supply power to a transporting means, and is divided into every region having a predetermined length. Each of the power supply bus bar regions is controlled for the power supply by a control device. Accordingly, the transporting means can be moved and driven successively being independent on every power supply bus bar region. Accordingly, a plurality of transporting means can be operated independently in a transferring path without laying around power cables and control signal cables. (I.S.)

Control of coal-dust in mines. Second edition. Bor'ba s ugol'noi i porodnoi pyl'yu v shakhtakh

Energy Technology Data Exchange (ETDEWEB)

Pemrukhin, P.M.; Grodel, G.S.; Zhilyaev, N.I.; Korenev, A.P.; Krivokhizha, B.M.; Kul' bachnyi, A.N.; Lyubimoba, A.I.; Medvedev, E.N.; Yaremachenko, P.P.

1981-01-01

An examination is made of problems concerned with over-all removal of dust from the air in mines. A description is given of physical and physico-chemical properties of ore mine dust that are of importance to evaluating processes in the formation, propagation and suppression of dust. Results are given for theoretical and on-site studies of dust aerodynamics in mines. A presentation is made of contemporary measures for controlling coal and rock dust in mines as well as means and methods of controlling air dust-level. Technical characteristics are given for new instruments for measuring air dust level. Brief data are given on preliminary wetting of coal in a massif, and a discussion is made of theoretical and practical problems related to hydro-dedusting, dust suppression, and dust removal during the operation of mining machinery as well as instruments for dedusting air on the surface complex of a mine. The book is intended for engineering-technical personnel in coal mines, design-planning and scientific-research institutes. 52 references, 61 tables.

Operation control device under radiation exposure

International Nuclear Information System (INIS)

Kimura, Kiichi; Murakami, Toichi.

1994-01-01

The device of the present invention performs smooth progress of operation by remote control for a plurality of operations in periodical inspections in controlled areas of a nuclear power plant, thereby reducing the operator's exposure dose. Namely, the device monitors the progressing state of the operation by displaying the progress of operation on a CRT of a centralized control device present in a low dose area remote from an operation field through an ITV camera disposed in the vicinity of the operation field. Further, operation sequence and operation instruction procedures previously inputted in the device are indicated to the operation field through an operation instruction outputting device (field CRT) in accordance with the progress of the operation steps. On the other hand, the operation progress can be aided by inputting information from the operation field such as start or completion of the operation steps. Further, the device of the present invention can monitor the change of operation circumstances and exposure dose of operators based on the information from a radiation dose measuring device disposed in the operation circumstance and to individual operators. (I.S.)

Control System for Prosthetic Devices

Science.gov (United States)

Bozeman, Richard J. (Inventor)

1996-01-01

A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that of movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrg position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.

Studies of mobile dust in scrape-off layer plasmas using silica aerogel collectors

Energy Technology Data Exchange (ETDEWEB)

Bergsaker, H., E-mail: henricb@kth.se [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Ratynskaia, S. [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Litnovsky, A. [Institut fur Energieforschung - Plasmaphysik, Forschungszentrum Julich, Trilateral Euregio Cluster, Association EURATOM-FZ Julich, D-52425 Julich (Germany); Ogata, D. [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Sahle, W. [Functional Materials Division, KTH-Electrum 229, Isafjordsgatan 22, SE-16440 Stockholm (Sweden)

2011-08-01

Dust capture with ultralow density silica aerogel collectors is a new method, which allows time resolved in situ capture of dust particles in the scrape-off layers of fusion devices, without substantially damaging the particles. Particle composition and morphology, particle flux densities and particle velocity distributions can be determined through appropriate analysis of the aerogel surfaces after exposure. The method has been applied in comparative studies of intrinsic dust in the TEXTOR tokamak and in the Extrap T2R reversed field pinch. The analysis methods have been mainly optical microscopy and SEM. The method is shown to be applicable in both devices and the results are tentatively compared between the two plasma devices, which are very different in terms of edge plasma conditions, time scale, geometry and wall materials.

Operation control device for nuclear power plants

International Nuclear Information System (INIS)

Suto, Osamu.

1982-01-01

Purpose: To render the controlling functions of a central control console more centralized by constituting the operation controls for a nuclear power plant with computer systems having substantially independent functions such as those of plant monitor controls, reactor monitor management and CRT display and decreasing interactions between each of the systems. Constitution: An input/output device for the input of process data for a nuclear power plant and indication data for a plant control console is connected to a plant supervisory and control computer system and a display computer system, the plant supervisory control computer system and a reactor and management computer system are connected with a CRT display control device, a printer and a CRT display input/output device, and the display computer system is connected with the CRT display control device and the CRT display unit on the central control console, whereby process input can be processed and displayed at high speed. (Yoshino, Y.)

Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

Energy Technology Data Exchange (ETDEWEB)

Yang, Changyi [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Wu, Yiyong; Lv, Gang [National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin (China); Rubanov, Sergey [Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010 (Australia); Jamieson, David N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

2015-04-01

Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

International Nuclear Information System (INIS)

Yang, Changyi; Wu, Yiyong; Lv, Gang; Rubanov, Sergey; Jamieson, David N.

2015-01-01

Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

On interaction of large dust grains with fusion plasma

International Nuclear Information System (INIS)

Krasheninnikov, S. I.; Smirnov, R. D.

2009-01-01

So far the models used to study dust grain-plasma interactions in fusion plasmas neglect the effects of dust material vapor, which is always present around dust in rather hot and dense edge plasma environment in fusion devices. However, when the vapor density and/or the amount of ionized vapor atoms become large enough, they can alter the grain-plasma interactions. Somewhat similar processes occur during pellet injection in fusion plasma. In this brief communication the applicability limits of the models ignoring vapor effects in grain-plasma interactions are obtained.

A controller for controlling a group of lighting devices and a method thereof

OpenAIRE

2017-01-01

A controller (100) for controlling a group (110) of lighting devices (112, 114) is disclosed. The group (110) comprises a first lighting device (112) and a second lighting device (114). The controller (100) comprises a communication unit (102) for communicating with the first and second lighting devices (112, 114), and for receiving a first current light setting of the first lighting device (112) and a second current light setting of the second lighting device (114). The controller (100) furt...

Testing device for control rod drives

International Nuclear Information System (INIS)

Hayakawa, Toshifumi.

1992-01-01

A testing device for control rod drives comprises a logic measuring means for measuring an output signal from a control rod drive logic generation circuit, a control means for judging the operation state of a control rod and a man machine interface means for outputting the result of the judgement. A driving instruction outputted from the control rod operation device is always monitored by the control means, and if the operation instruction is stopped, a testing signal is outputted to the control rod control device to simulate a control rod operation. In this case, the output signal of the control rod drive logic generation circuit is held in a control rod drive memory means and intaken into a logic analysis means for measurement and an abnormality is judged by the control means. The stopping of the control rod drive instruction is monitored and the operation abnormality of the control rod is judged, to mitigate the burden of an operator. Further, the operation of the control rod drive logic generation circuit can be confirmed even during a nuclear plant operation by holding the control rod drive instruction thereby enabling to improve maintenance efficiency. (N.H.)

Reactor core control device

International Nuclear Information System (INIS)

Sano, Hiroki

1998-01-01

The present invention provides a reactor core control device, in which switching from a manual operation to an automatic operation, and the control for the parameter of an automatic operation device are facilitated. Namely, the hysteresis of the control for the operation parameter by an manual operation input means is stored. The hysteresis of the control for the operation parameter is collected. The state of the reactor core simulated by an operation control to which the collected operation parameters are manually inputted is determined as an input of the reactor core state to the automatic input means. The record of operation upon manual operation is stored as a hysteresis of control for the operation parameter, but the hysteresis information is not only the result of manual operation of the operation parameter. This is results of operation conducted by a skilled operator who judge the state of the reactor core to be optimum. Accordingly, it involves information relevant to the reactor core state. Then, it is considered that the optimum automatic operation is not deviated greatly from the manual operation. (I.S.)

The global distribution of mineral dust

International Nuclear Information System (INIS)

Tegen, I; Schepanski, K

2009-01-01

Dust aerosol particles produced by wind erosion in arid and semi arid regions affect climate and air quality, but the magnitude of these effects is largely unquantified. The major dust source regions include the Sahara, the Arabian and Asian deserts; global annual dust emissions are currently estimated to range between 1000 and 3000 Mt/yr. Dust aerosol can be transported over long distances of thousands of kilometers, e.g. from source regions in the Saharan desert over the North Atlantic, or from the Asian deserts towards the Pacific Ocean. The atmospheric dust load varies considerably on different timescales. While dust aerosol distribution and dust effects are important on global scales, they strongly depend on dust emissions that are controlled on small spatial and temporal scales.

Control Strategies for Arrays of Wave Energy Devices

OpenAIRE

Westphalen, J; Bacelli, G; Balitsky, P; Ringwood, John

2011-01-01

In this paper, we investigate the differences between two control strategies for a two-device linear array of wave energy converters (WEC) for device spacings of 4 to 80 times the device diameter. The WECs operate in heave only and are controlled in real time. The control strategies, called the independent device and global array control, estimate the excitation forces and calculate the optimum vertical velocity trajectory and reactive power take off force to achieve the ...

Laser-induced mobilization of dust produced during fusion reactors operation

International Nuclear Information System (INIS)

Vatry, A.

2010-01-01

During tokamak operation, plasma-wall interactions lead to material erosion process and dusts production. These dusts are mainly composed by carbon and tungsten, with sizes ranging from 10 nm to 100 μm. For safety reasons and to guarantee an optimum reactor functioning, the dusts have to be kept in reasonable quantity. The dusts mobilization is a first step to collect them, and the laser is a promising technique for this application. To optimize the cleaning, physical mechanisms responsible for dust ejection induced by laser have been identified. Some particles, such as aggregates, are directly ablated by the laser. The metal droplets are ejected intact by an electrostatic force, induced by the photoelectrons. We also characterized the particles ejection to choose an appropriate collection device. (author) [fr

He Puff System For Dust Detector Upgrade

International Nuclear Information System (INIS)

Rais, B.; Skinner, C.H.; Roquemore, A.L.

2010-01-01

Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a 5 cm x 5 cm grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment (NSTX). We report on a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. The entire surface of the detector was cleared of carbon particles by two consecutive helium puffs delivered by three nozzles of 0.45 mm inside diameter. The optimal configuration was found to be with the nozzles at an angle of 30o with respect to the surface of the detector and a helium backing pressure of 6 bar.

Plasma position and shape control device for thermonuclear device

International Nuclear Information System (INIS)

Takeuchi, Kazuhiro; Abe, Mitsushi; Kinoshita, Shigemi.

1993-01-01

A plasma position and shape control system is constituted with a measuring device, a quenching probability calculation section and a control calculation section. A quenching probability is calculated in the quenching probability calculation section by using a measuring data on temperature, electric current and magnetic field of superconductive coils, based on a margin upto a limit value. The control calculation section selects a control method which decreases applied voltage or current instruction value as the quenching probability of the coils is higher. Since the quenching probability of the superconductive coils can be forecast and a state of low quenching danger can be selected, the safety of the device is improved. When the quenching danger is allowed to a predetermined value, a wide operation region can be provided. (N.H.)

Hypervelocity Dust Impacts in Space and the Laboratory

Science.gov (United States)

Horanyi, Mihaly; Colorado CenterLunar Dust; Atmospheric Studies (CCLDAS) Team

2013-10-01

Interplanetary dust particles continually bombard all objects in the solar system, leading to the excavation of material from the target surfaces, the production of secondary ejecta particles, plasma, neutral gas, and electromagnetic radiation. These processes are of interest to basic plasma science, planetary and space physics, and engineering to protect humans and instruments against impact damages. The Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) has recently completed a 3 MV dust accelerator, and this talk will summarize our initial science results. The 3 MV Pelletron contains a dust source, feeding positively charged micron and sub-micron sized particles into the accelerator. We will present the technical details of the facility and its capabilities, as well as the results of our initial experiments for damage assessment of optical devices, and penetration studies of thin films. We will also report on the completion of our dust impact detector, the Lunar Dust Experiment (LDEX), is expected to be flying onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission by the time of this presentation. LDEX was tested, and calibrated at our dust accelerator. We will close by offering the opportunity to use this facility by the planetary, space and plasma physics communities.

A dust-free dock

Energy Technology Data Exchange (ETDEWEB)

Merrion, D. [E & F Services Ltd. (United Kingdom)

2002-10-01

This paper describes the process of unloading coal, petcoke and other dusty products in environmentally-sensitive areas. It presents a case study of the deepwater Port of Foynes on the west coast of Ireland which imports animal feed, fertiliser, coal and cement clinker, where dockside mobile loaders (DMLs) have eliminated spillage and controlled dust, and a record case study of the Humber International Terminal in the UK, where air curtinas, dust suppression grids and EFFEX{reg_sign} filters overcome the dust problems. 2 photos.

GPK helmet for protection from gas and dust

Energy Technology Data Exchange (ETDEWEB)

Ilinskiy, E.G.; Kogan, Yu.A.; Mazanenko, V.P.

1983-01-01

An examination is made of the purpose, area of application, operating principle, technical characteristics, and also results of testing a new device for individual protection of miners from gas and dust are examined.

FACTS device control strategy using PMU

Directory of Open Access Journals (Sweden)

Mohd Tauseef Khan

2016-09-01

Full Text Available The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

From explosions to black lung: a history of efforts to control coal mine dust.

Science.gov (United States)

Weeks, J L

1993-01-01

Highlights in the history of efforts to prevent occupational lung disease among coal miners in the United States are reviewed. The Federal Coal Mine Health and Safety Act of 1969 is summarized, and the sources and effects of its provisions to prevent coal workers' pneumoconiosis are examined. Descriptions follow of the identification of coal workers' pneumoconiosis as a disease, identification of respirable coal mine dust as its cause, and establishment and enforcement of an exposure limit. The development of prevention efforts focusing on surveillance of both exposure and outcome and of enforcement of dust control methods is examined.

Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

Energy Technology Data Exchange (ETDEWEB)

Jaiswal, S., E-mail: surabhijaiswal73@gmail.com; Bandyopadhyay, P.; Sen, A. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

2016-08-15

We report on experimental observations of flow induced large amplitude dust-acoustic shock waves in a complex plasma. The experiments have been carried out in a Π shaped direct current glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change in the gas flow rate is used to trigger the onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a modified Korteweg-de-Vries-Burgers type equation.

DEVICE FOR CONTROL OF OXYGEN PARTIAL PRESSURE

Science.gov (United States)

Bradner, H.; Gordon, H.S.

1957-12-24

A device is described that can sense changes in oxygen partial pressure and cause a corresponding mechanical displacement sufficient to actuate meters, valves and similar devices. A piston and cylinder arrangement contains a charge of crystalline metal chelate pellets which have the peculiar property of responding to variations in the oxygen content of the ambient atmosphere by undergoing a change in dimension. A lever system amplifies the relative displacement of the piston in the cylinder, and actuates the controlled valving device. This partial pressure oxygen sensing device is useful in controlled chemical reactions or in respiratory devices such as the oxygen demand meters for high altitude aircraft.

Regional and climatic controls on seasonal dust deposition in the southwestern U.S.

Science.gov (United States)

Reheis, M.C.; Urban, F.E.

2011-01-01

Vertical dust deposition rates (dust flux) are a complex response to the interaction of seasonal precipitation, wind, changes in plant cover and land use, dust source type, and local vs. distant dust emission in the southwestern U.S. Seasonal dust flux in the Mojave-southern Great Basin (MSGB) deserts, measured from 1999 to 2008, is similar in summer-fall and winter-spring, and antecedent precipitation tends to suppress dust flux in winter-spring. In contrast, dust flux in the eastern Colorado Plateau (ECP) region is much larger in summer-fall than in winter-spring, and twice as large as in the MSGB. ECP dust is related to wind speed, and in the winter-spring to antecedent moisture. Higher summer dust flux in the ECP is likely due to gustier winds and runoff during monsoonal storms when temperature is also higher. Source types in the MSGB and land use in the ECP have important effects on seasonal dust flux. In the MSGB, wet playas produce salt-rich dust during wetter seasons, whereas antecedent and current moisture suppress dust emission from alluvial and dry-playa sources during winter-spring. In the ECP under drought conditions, dust flux at a grazed-and-plowed site increased greatly, and also increased at three annualized, previously grazed sites. Dust fluxes remained relatively consistent at ungrazed and currently grazed sites that have maintained perennial vegetation cover. Under predicted scenarios of future climate change, these results suggest that an increase in summer storms may increase dust flux in both areas, but resultant effects will depend on source type, land use, and vegetation cover. ?? 2011.

Tungsten dust remobilization under steady-state and transient plasma conditions.

Czech Academy of Sciences Publication Activity Database

Ratynskaia, S.; Tolias, P.; De Angeli, M.; Weinzettl, Vladimír; Matějíček, Jiří; Bykov, I.; Rudakov, D.L.; Vignitchouk, L.; Thorén, E.; Riva, G.; Ripamonti, D.; Morgan, T.; Pánek, Radomír; De Temmerman, G.

2017-01-01

Roč. 12, August (2017), s. 569-574 ISSN 2352-1791. [PSI 2016 - 22nd International Conference on Plasma Surface Interactions in Controlled Fusion Devices/22./. Roma, 30.05.2016-03.06.2016] R&D Projects: GA ČR(CZ) GA14-12837S; GA MŠk(CZ) LM2015045 EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 Keywords : Tungsten * Dust * Remobilization * Tokamak Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) http://www.sciencedirect.com/science/article/pii/S2352179116301168

Optimization of Photovoltaic Performance Through the Integration of Electrodynamic Dust Shield Layers

Science.gov (United States)

Nason, Steven; Davis, Kris; Hickman, Nicoleta; McFall, Judith; Arens, Ellen; Calle, Carlos

2009-01-01

The viability of photovoltaics on the Lunar and Martian surfaces may be determined by their ability to withstand significant degradation in the Lunar and Martian environments. One of the greatest threats is posed by fine dust particles which are continually blown about the surfaces. In an effort to determine the extent of the threat, and to investigate some abatement strategies, a series of experiments were conducted outdoors and in the Moon and Mars environmental chamber at the Florida Solar Energy Center. Electrodynamic dust shield prototypes based on the electric curtain concept have been developed by our collaborators at the Kennedy Space Center [1]. These thin film layers can remove dust from surfaces and prevent dust accumulation. Several types of dust shields were designed, built and tested under high vacuum conditions and simulated lunar gravity to validate the technology for lunar exploration applications. Gallium arsenide, single crystal and polycrystalline silicon photovoltaic integrated devices were designed, built and tested under Moon and Mars environmental conditions as well as under ambient conditions. Photovoltaic efficiency measurements were performed on each individual cell with the following configurations; without an encapsulation layer, with a glass covering, and with various thin film dust shields. It was found that the PV efficiency of the hybrid systems was unaffected by these various thin film dust shields, proving that the optical transmission of light through the device is virtually uninhibited by these layers. The future goal of this project is to incorporate a photovoltaic cell as the power source for the electrodynamic dust shield system, and experimentally show the effective removal of dust obstructing any light incident on the cell, thus insuring power production is maximized over time.

Electronic design of air dust concentration gauge

International Nuclear Information System (INIS)

Machaj, B.; Strzalkowski, J.; Krawczynska, B.

1993-01-01

A new version of isotope dust concentration gauge for monitoring airborne dust pollution of air employs a ready made personal computer as the control and processing unit in the gauge instead of specialized electronics. That solution of the gauge reduces the needed specialized electronics to a simple computer interface coupling the computer to the measuring head. This also reduced electronics of the measuring head itself, i.e. GM detector circuit, power supplies and electronic circuits to switch on/off driving motors. The functioning and operation of the gauge is controlled by the computer program that can be easily modified if needed. The computer program for the gauge enables automatic measurements of dust concentration. Up to fifty measuring cycles can be easily programmed for a day. The results of measurements are presented in the form of data collection, diagram of dust concentration distribution during one day, diagram of dust distribution during 30 successive days or diagram of average dust concentration distribution during a day which may be computed by combining data of the selected number of measurements. Recalibration of the gauge and checking up of the gauge are also carried out under the program control. (author). 6 refs, 9 figs

Brain-controlled body movement assistance devices and methods

Energy Technology Data Exchange (ETDEWEB)

Leuthardt, Eric C.; Love, Lonnie J.; Coker, Rob; Moran, Daniel W.

2017-01-10

Methods, devices, systems, and apparatus, including computer programs encoded on a computer storage medium, for brain-controlled body movement assistance devices. In one aspect, a device includes a brain-controlled body movement assistance device with a brain-computer interface (BCI) component adapted to be mounted to a user, a body movement assistance component operably connected to the BCI component and adapted to be worn by the user, and a feedback mechanism provided in connection with at least one of the BCI component and the body movement assistance component, the feedback mechanism being configured to output information relating to a usage session of the brain-controlled body movement assistance device.

Reactor power control device

International Nuclear Information System (INIS)

Ishii, Yoshihiko; Arita, Setsuo; Miyamoto, Yoshiyuki; Fukazawa, Yukihisa; Ishii, Kazuhiko

1998-01-01

The present invention provides a reactor power control device capable of enhancing an operation efficiency while keeping high reliability and safety in a BWR type nuclear power plant. Namely, the device of the present invention comprises (1) a means for inputting a set value of a generator power and a set value of a reactor power, (2) a means for controlling the reactor power to either smaller one of the reactor power corresponding to the set value of the generator power and the set value of the reactor power. With such procedures, even if the nuclear power plant is set so as to operate it to make the reactor power 100%, when the generator power reaches the upper limit, the reactor power is controlled with a preference given to the upper limit value of the generator power. Accordingly, safety and reliability are not deteriorated. The operation efficiency of the plant can be improved. (I.S.)

Plasma control device

International Nuclear Information System (INIS)

Matsutomi, Akiyoshi.

1995-01-01

Plasma position and shape estimation values are outputted based on measured values of coil current. When the measured values of the position and the shape are judged to be abnormal, position and shape estimation values estimated by a plasma position and shape estimation means are outputted as position and shape feed back values to a plasma position and shape control means instead of the position and shape measured values. Since only a portion of the abnormal position and shape measured values may also be replaced with the position and shape estimation values, errors in the plasma position and shape feed back values can be reduced as a whole. In addition, even if the position and shape measured values are abnormal or if they can not be measured, plasma control can be continued by alternative position and shape estimation values, thereby enabling to avoid interruption of plasma control. Since the position and shape estimation values are obtained not only with the measured values of coil current but also with the position and shape estimation values, the accuracy is improved. Further, noises superposed on the position and shape measured values are filtered, and the device is stabilized compared with a prior art device. (N.H.)

A controller for controlling a group of lighting devices and a method thereof

NARCIS (Netherlands)

2017-01-01

A controller (100) for controlling a group (110) of lighting devices (112, 114) is disclosed. The group (110) comprises a first lighting device (112) and a second lighting device (114). The controller (100) comprises a communication unit (102) for communicating with the first and second lighting

Modulational instability of ultra-low-frequency shear dust Alfvén waves in a plasma medium of positive and negatively charged dust fluids

International Nuclear Information System (INIS)

Mamun, A. A.

2014-01-01

The propagation of finite amplitude ultra-low-frequency shear dust Alfvén (SDA) waves, and their modulational instability in a magnetized plasma medium of positive and negatively charged dust fluids have been theoretically investigated by using the reductive perturbation method. The derivative nonlinear Schrödinger equation is derived to examine the stability analysis of such SDA waves. It is found that the SDA waves propagating in such an opposite polarity dust plasma medium are modulationally unstable, and that the instability criterion and the growth rate of these unstable SDA waves in such a novel opposite polarity dust plasma medium are found to be significantly different from those in electron–ion or electron–positron plasma media. The implications of the present investigation in different space environments and laboratory devices are briefly discussed.

The effective and dust free receiving station and handling for the low calorific value solid fuels; Tehokas ja poelytoen seospolttoaineiden vastaanottoasema sekae kaesittely- ja kuljetinjaerjestelmae

Energy Technology Data Exchange (ETDEWEB)

Nojonen, O. [Finntech Oy, Espoo (Finland); Jaervinen, T. [VTT Energy, Jyvaeskylae (Finland). Energy Use

1995-12-31

The aim of the project was to get higher automatization level and improve dust preventing in solid fuel receiving stations. There are two general types of receiving stations in the Finnish power plants: large unloading stations for the side tipping devices of trucks and small ones for the rear tipping devices of trucks. In the first ones the trucks empty their load (approx. 100 m{sup 3} loose bulk density) divided by hauling unit and trailer within few (5-10) minutes into a rectangular box, which depth is approx. 3 m. The discharging causes a strong counter current air and dust flow (20-40 m{sup 3}/s) upwards and the dust will easily spread out all over the station. In the second ones the discharging takes place from the rear of truck and trailer using loadspace conveyor of the vehicle within 20 minutes. The material falls on a (belt) conveyor, which is on the floor level. The problems in side tipping system are connected with dust and surplus time, which is needed for the preparation and completion of unloading and sampling. For the fine dust control has also been tested water spray (fog) nozzles and tried to utilise a settling chamber for the dust stream. Also the using the settling chamber equipped with air suction connections and cyclone separation may be effective. In the rear tipping system are also applied bag filters because of smaller air quantities. The rapid truck positioning and control in the receiving station is one of the presupposition for the fast and accurate unloading. This can be done using ultrasonic sensing methods. Also the ensuring of accurate discharging can be based on the modern technology. One of the basic things is the enlarging of video control (CCD -cameras)

The effective and dust free receiving station and handling for the low calorific value solid fuels; Tehokas ja poelytoen seospolttoaineiden vastaanottoasema sekae kaesittely- ja kuljetinjaerjestelmae

Energy Technology Data Exchange (ETDEWEB)

Nojonen, O [Finntech Oy, Espoo (Finland); Jaervinen, T [VTT Energy, Jyvaeskylae (Finland). Energy Use

1996-12-31

The aim of the project was to get higher automatization level and improve dust preventing in solid fuel receiving stations. There are two general types of receiving stations in the Finnish power plants: large unloading stations for the side tipping devices of trucks and small ones for the rear tipping devices of trucks. In the first ones the trucks empty their load (approx. 100 m{sup 3} loose bulk density) divided by hauling unit and trailer within few (5-10) minutes into a rectangular box, which depth is approx. 3 m. The discharging causes a strong counter current air and dust flow (20-40 m{sup 3}/s) upwards and the dust will easily spread out all over the station. In the second ones the discharging takes place from the rear of truck and trailer using loadspace conveyor of the vehicle within 20 minutes. The material falls on a (belt) conveyor, which is on the floor level. The problems in side tipping system are connected with dust and surplus time, which is needed for the preparation and completion of unloading and sampling. For the fine dust control has also been tested water spray (fog) nozzles and tried to utilise a settling chamber for the dust stream. Also the using the settling chamber equipped with air suction connections and cyclone separation may be effective. In the rear tipping system are also applied bag filters because of smaller air quantities. The rapid truck positioning and control in the receiving station is one of the presupposition for the fast and accurate unloading. This can be done using ultrasonic sensing methods. Also the ensuring of accurate discharging can be based on the modern technology. One of the basic things is the enlarging of video control (CCD -cameras)

The effect of cleanliness control during installation work on the amount of accumulated dust in ducts of new HVAC installations.

Science.gov (United States)

Holopainen, R; Tuomainen, M; Asikainen, V; Pasanen, P; Säteri, J; Seppänen, O

2002-09-01

The aim of this study was to evaluate the amount of dust in supply air ducts in recently installed ventilation systems. The samples for the determination of dust accumulation were collected from supply air ducts in 18 new buildings that have been constructed according to two different cleanliness control levels classified as category P1 (low oil residues and protected against contaminations) and category P2, as defined in the Classification of Indoor Climate, Construction and Building Materials. In the ducts installed according to the requirements of cleanliness category P1 the mean amount of accumulated dust was 0.9 g/m2 (0.4-2.9 g/m2), and in the ducts installed according to the cleanliness category P2 it was 2.3 g/m2 (1.2-4.9 g/m2). A significant difference was found in the mean amounts of dust between ducts of categories P1 and P2 (P < 0.008). The cleanliness control procedure in category P1 proved to be a useful and effective tool for preventing dust accumulation in new air ducts during the construction process. Additionally, the ducts without residual oil had lower amounts of accumulated dust indicating that the demand for oil free components in the cleanliness classification is reasonable.

Dust and radon: the legal implications

International Nuclear Information System (INIS)

Van Sittert, J.M.O.

1990-01-01

It is known that radon gas is not generally considered to be a major problem when encountered in the working environment. However, in its process of decay, a series of four short lived daughter products are formed. In a dust-laden atmosphere these daughter products, which are ionized readily, attach to the particulate material and when inhaled are deposited in the alveoli of the lungs. Therefore, if respirable dust is controlled, the effects of radon daughters will also be minimized. The legal requirements for dust control in South Africa and their implications are discussed. 1 ill

Utilization of ultrasonic atomization for dust control in underground mining

Science.gov (United States)

Okawa, Hirokazu; Nishi, Kentaro; Kawamura, Youhei; Kato, Takahiro; Sugawara, Katsuyasu

2017-07-01

This study examined dust suppression using water particles generated by ultrasonic atomization (2.4 MHz) at low temperature (10 °C). Green tuff (4 µm), green tuff (6 µm), kaolin, and silica were used as dust samples. Even though ultrasonic atomization makes fine water particles, raising relative air humidity immediately was difficult at low temperature. However, remaining water particles that did not change to water vapor contributed to suppression of dust dispersion. Additionally, the effect of water vapor amount (absolute humidity) and water particles generated by ultrasonic atomization on the amount of dust dispersion was investigated using experimental data at temperatures of 10, 20, and 30 °C. Utilization of ultrasound atomization at low temperature has the advantages of low humidity increments in the working space and water particles remaining stable even with low relative air humidity.

Dose response effect of cement dust on respiratory muscles competence in cement mill workers.

Science.gov (United States)

Meo, Sultan A; Azeem, Muhammad A; Qureshi, Aijaz A; Ghori, G Moinudin; Al-Drees, Abdul Majeed; Feisal Subhan, Mirza Muhammad

2006-12-01

Electromyography (EMG) of respiratory muscles is a reliable method of assessing the ventilatory muscle function, but still its use has not been fully utilized to determine the occupational and environmental hazards on respiratory muscles. Therefore, EMG of intercostal muscles was performed to determine the dose response effect of cement dust on respiratory muscles competence. Matched cross-sectional study of EMG in 50 non-smoking cement mill workers with an age range of 20 - 60 years, who worked without the benefit of cement dust control ventilation or respiratory protective devices. EMG was performed by using surface electrodes and chart recorder. Significant reduction was observed in number of peaks (p competence and stratification of results shows a dose-effect of years of exposure in cement mill.

System for remote control of underground device

Science.gov (United States)

Brumleve, T.D.; Hicks, M.G.; Jones, M.O.

1975-10-21

A system is described for remote control of an underground device, particularly a nuclear explosive. The system includes means at the surface of the ground for transmitting a seismic signal sequence through the earth having controlled and predetermined signal characteristics for initiating a selected action in the device. Additional apparatus, located with or adjacent to the underground device, produces electrical signals in response to the seismic signals received and compares these electrical signals with the predetermined signal characteristics.

System for remote control of underground device

International Nuclear Information System (INIS)

Brumleve, T.D.; Hicks, M.G.; Jones, M.O.

1975-01-01

A system is described for remote control of an underground device, particularly a nuclear explosive. The system includes means at the surface of the ground for transmitting a seismic signal sequence through the earth having controlled and predetermined signal characteristics for initiating a selected action in the device. Additional apparatus, located with or adjacent to the underground device, produces electrical signals in response to the seismic signals received and compares these electrical signals with the predetermined signal characteristics

Paleo-dust insights onto dust-climate interactions

Science.gov (United States)

Albani, S.; Mahowald, N. M.

2017-12-01

Mineral dust emissions are affected by changing climate conditions, and in turn dust impacts the atmospheric radiation budget, clouds and biogeochemical cycles. Climate and public health dust-related issues call for attention on the fate of the dust cycle in the future, and the representation of the dust cycle is now part of the strategy of the Paleoclimate Modelling Intercomparison Project phase 4 and the Coupled Model Intercomparison Project phase 6 (PMIP4-CMIP6). Since mineral aerosols are one of the most important natural aerosols, understanding past dust responses to climate in the paleoclimate will allow us to better understand mineral aerosol feedbacks with climate and biogeochemistry in the Anthropocene. Modern observations and paleoclimate records offer the possibility of multiple, complementary views on the global dust cycle, and allow to validate and/or constrain the numerical representation of dust in climate and Earth system models. We present our results from a set of simulations with the Community Earth System Model for different climate states, including present and past climates such as the pre-industrial, the mid-Holocene and the Last Glacial Maximum. A set of simulations including a prognostic dust cycle was thoroughly compared with a wide set of present day observations from different platforms and regions, in order to realistically constrain the magnitude of dust load, surface concentration, deposition, optical properties, and particle size distributions. The magnitude of emissions for past climate regimes was constrained based on compilations of paleodust mass accumulation rates and size distributions, as well as based on information on dust provenance. The comparison with a parallel set of simulations without dust allows estimating the impacts of dust on surface climate. We analyze impacts of dust on the mean and variability of surface temperature and precipitation in each climate state, as well as the impacts that changing dust emissions had

Effectiveness of dust control methods for crystalline silica and respirable suspended particulate matter exposure during manual concrete surface grinding.

Science.gov (United States)

Akbar-Khanzadeh, Farhang; Milz, Sheryl A; Wagner, Cynthia D; Bisesi, Michael S; Ames, April L; Khuder, Sadik; Susi, Pam; Akbar-Khanzadeh, Mahboubeh

2010-12-01

Concrete grinding exposes workers to unacceptable levels of crystalline silica dust, known to cause diseases such as silicosis and possibly lung cancer. This study examined the influence of major factors of exposure and effectiveness of existing dust control methods by simulating field concrete grinding in an enclosed workplace laboratory. Air was monitored during 201 concrete grinding sessions while using a variety of grinders, accessories, and existing dust control methods, including general ventilation (GV), local exhaust ventilation (LEV), and wet grinding. Task-specific geometric mean (GM) of respirable crystalline silica dust concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled-grinding, while GV was off/on, were 0.17/0.09, 0.57/0.13, 1.11/0.44, and 23.1/6.80, respectively. Silica dust concentrations (mg/m³ using 100-125 mm (4-5 inch) and 180 mm (7 inch) grinding cups were 0.53/0.22 and 2.43/0.56, respectively. GM concentrations of silica dust were significantly lower for (1) GV on (66.0%) vs. off, and (2) LEV:HEPA- (99.0%), LEV:Shop-vac- (98.1%) or wet- (94.4%) vs. uncontrolled-grinding. Task-specific GM of respirable suspended particulate matter (RSP) concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled grinding, while GV was off/on, were 1.58/0.63, 7.20/1.15, 9.52/4.13, and 152/47.8, respectively. GM concentrations of RSP using 100-125 mm and 180 mm grinding cups were 4.78/1.62 and 22.2/5.06, respectively. GM concentrations of RSP were significantly lower for (1) GV on (70.2%) vs. off, and (2) LEV:HEPA- (98.9%), LEV:Shop-vac- (96.9%) or wet- (92.6%) vs. uncontrolled grinding. Silica dust and RSP were not significantly affected by (1) orientation of grinding surfaces (vertical vs. inclined); (2) water flow rates for wet grinding; (3) length of task-specific sampling time; or, (4) among cup sizes of 100, 115 or 125 mm. No combination of factors or control methods reduced an 8-hr exposure level to below the

Testing device for pipeline groups and control method for testing device

International Nuclear Information System (INIS)

Naito, Shinji; Kajiyama, Shigeru; Takahashi, Fuminobu; Tsuchida, Kenji; Tachibana, Yukio; Shigehiro, Katsuya; Mahara, Yoichi.

1995-01-01

The device of the present invention comprises a testing device main body disposed to a rail, a movable mechanism positioning from a reference point, a circumferential direction scanning mechanism, an axial direction scanning mechanism, a posture control mechanism, and a testing probe. Upon testing of pipelines, the detection device main body and auxiliary members are moved from a reference point previously set on a rail for numerical control toward pipelines to be tested in a state where the axial direction scanning mechanism and the testing probe are suspended in the axial direction. The testing is conducted by controlling the position of the testing probe in the axial direction of the pipeline by means of the axial direction scanning mechanism, and scanning the testing probe to the outer circumference of the pipeline along the circumferential track by way of the circumferential direction scanning mechanism. The device can be extremely reduced in the thickness, and can be moved with no interference with pipelines and other obstacles by remote operation even under such undesired condition as the pipelines being crowded, so that non-destructive testing can be conducted accurately. (N.H.)

Power control device

International Nuclear Information System (INIS)

Fukawa, Naohiro.

1982-01-01

Purpose: To alleviate the load of an operator by automatically operating the main controller, the speed controller, etc. of a recirculation control system and safely operating them without erroneous operation for long period of time, thereby improving the efficiency of a plant. Constitution: An electric type hydraulic control device controls loads of a turbine and a generator and outputs a control signal also to the main controller of a recirculation flow rate control system. At this time, the main controller is set at an automatic position, and the speed controller receives a recirculation pump speed signal from the main controller at the automatic position. The speed controller outputs a pump speed control signal to the recirculation pump system, and a reactor generates a power corresponding thereto. When the power control is automatically performed by the recirculation flow rate control, an operator sets a rate of change of the recirculation pump speed and the rate of change of the mean power range monitor at a change rate setting unit. Therefore, the control of the recirculation flow rate under the power control can be substantially entirely automated. (Yoshigara, H.)

Advances in Electrostatic Dust Detection on Remote Surfaces

International Nuclear Information System (INIS)

Voinier, C.; Skinner, C.H.; Roquemore, A.L.

2005-01-01

The inventory of dust in next-step magnetic fusion devices will be regulated for safety reasons, however diagnostics to measure in-vessel dust are still in their infancy. Advances in dust particle detection on remote surfaces are reported. Two grids of interlocking circuit traces with spacing in the range 125 (micro)m to 25 (micro)m are biased to 30 V. Impinging dust creates a short circuit and the result current pulse is recorded. The detector response was measured with particles scraped from a carbon fiber composite tile and sorted by size category. The finest 25 (micro)m grid showed a sensitivity more than an order of magnitude higher than the 125 (micro)m grid. The response to the finest particle categories (5-30 (micro)m) was two orders of magnitude higher than the largest (125-250 (micro)m) category. Longer duration current pulses were observed from the coarser particles. The results indicate a detection threshold for fine particles below 1 (micro)g/cm 2

Studies on plasma profiles and its effect on dust charging in hydrogen plasma

Science.gov (United States)

Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhay, M.

2010-02-01

Plasma profiles and its influence on dust charging are studied in hydrogen plasma. The plasma is produced in a high vacuum device by a hot cathode discharge method and is confined by a cusped magnetic field cage. A cylindrical Espion advanced Langmuir probe having 0.15 mm diameter and 10.0 mm length is used to study the plasma parameters for various discharge conditions. Optimum operational discharge parameters in terms of charging of the dust grains are studied. The charge on the surface of the dust particle is calculated from the capacitance model and the current by the dust grains is measured by the combination of a Faraday cup and an electrometer. Unlike our previous experiments in which dust grains were produced in-situ, here a dust dropper is used to drop the dust particles into the plasma.

Studies on plasma profiles and its effect on dust charging in hydrogen plasma

International Nuclear Information System (INIS)

Kakati, B; Kausik, S S; Saikia, B K; Bandyopadhay, M

2010-01-01

Plasma profiles and its influence on dust charging are studied in hydrogen plasma. The plasma is produced in a high vacuum device by a hot cathode discharge method and is confined by a cusped magnetic field cage. A cylindrical Espion advanced Langmuir probe having 0.15 mm diameter and 10.0 mm length is used to study the plasma parameters for various discharge conditions. Optimum operational discharge parameters in terms of charging of the dust grains are studied. The charge on the surface of the dust particle is calculated from the capacitance model and the current by the dust grains is measured by the combination of a Faraday cup and an electrometer. Unlike our previous experiments in which dust grains were produced in-situ, here a dust dropper is used to drop the dust particles into the plasma.

Automatic exchange unit for control rod drive device

International Nuclear Information System (INIS)

Nasu, Seiji; Sasaki, Masayoshi.

1982-01-01

Purpose: To enable automatic reoperation and continuation without external power interruption remedy device at the time of recovering the interrupted power soruce during automatic positioning operation. Constitution: In case of an automatic exchange unit for a control rod drive device of the control type for setting the deviation between the positioning target position and the present position of the device to zero, the position data of the drive device of the positioning target value of the device is automatically read, and an interlock of operation inhibit is applied to a control system until the data reading is completed and automatic operation start or restart conditions are sequentially confirmed. After the confirmation, the interlock is released to start the automatic operation or reoperation. Accordingly, the automatic operation can be safely restarted and continued. (Yoshihara, H.)

30 CFR 71.101 - Respirable dust standard when quartz is present.

Science.gov (United States)

2010-07-01

... during each shift to which each miner is exposed at or below a concentration of respirable dust computed... per cubic meter of air as measured with an approved sampling device and in terms of an equivalent concentration determined in accordance with § 71.206 (Approved sampling devices; equivalent concentrations...

30 CFR 70.101 - Respirable dust standard when quartz is present.

Science.gov (United States)

2010-07-01

... concentration of respirable dust in the mine atmosphere during each shift to which each miner in the active... of air as measured with an approved sampling device and in terms of an equivalent concentration determined in accordance with § 70.206 (Approved sampling devices; equivalent concentrations), computed by...

Response of the Eastern Mediterranean microbial ecosystem to dust and dust affected by acid processing in the atmosphere

Directory of Open Access Journals (Sweden)

Michael David Krom

2016-08-01

Full Text Available Acid processes in the atmosphere, particularly those caused by anthropogenic acid gases, increase the amount of bioavailable P in dust and hence are predicted to increase microbial biomass and primary productivity when supplied to oceanic surface waters. This is likely to be particularly important in the Eastern Mediterranean Sea (EMS, which is P limited during the winter bloom and N&P co-limited for phytoplankton in summer. However, it is not clear how the acid processes acting on Saharan dust will affect the microbial biomass and primary productivity in the EMS. Here, we carried out bioassay manipulations on EMS surface water on which Saharan dust was added as dust (Z, acid treated dust (ZA, dust plus excess N (ZN and acid treated dust with excess N (ZNA during springtime (May 2012 and measured bacterioplankton biomass, metabolic and other relevant chemical and biological parameters. We show that acid treatment of Saharan dust increased the amount of bioavailable P supplied by a factor of ~40 compared to non-acidified dust (18.4 nmoles P mg-1 dust vs. 0.45 nmoles P mg-1 dust, respectively. The increase in chlorophyll, primary and bacterial productivity for treatments Z and ZA were controlled by the amount of N added with the dust while those for treatments ZN and ZNA (in which excessive N was added were controlled by the amount of P added. These results confirm that the surface waters were N&P co-limited for phytoplankton during springtime. However, total chlorophyll and primary productivity in the acid treated dust additions (ZA and ZNA were less than predicted from that calculated from the amount of the potentially limiting nutrient added. This biological inhibition was interpreted as being due to labile trace metals being added with the acidified dust. A probable cause for this biological inhibition was the addition of dissolved Al, which forms potentially toxic Al nanoparticles when added to seawater. Thus, the effect of anthropogenic acid

Automatic operation device for control rods

International Nuclear Information System (INIS)

Sekimizu, Koichi

1984-01-01

Purpose: To enable automatic operation of control rods based on the reactor operation planning, and particularly, to decrease the operator's load upon start up and shutdown of the reactor. Constitution: Operation plannings, demand for the automatic operation, break point setting value, power and reactor core flow rate change, demand for operation interrupt, demand for restart, demand for forecasting and the like are inputted to an input device, and an overall judging device performs a long-term forecast as far as the break point by a long-term forecasting device based on the operation plannings. The automatic reactor operation or the like is carried out based on the long-term forecasting and the short time forecasting is performed by the change in the reactor core status due to the control rod operation sequence based on the control rod pattern and the operation planning. Then, it is judged if the operation for the intended control rod is possible or not based on the result of the short time forecasting. (Aizawa, K.)

Control rod guide tube cleaning device

International Nuclear Information System (INIS)

Tsuji, Tadashi; Shiota, Yoshiaki.

1990-01-01

Since there was no exclusive device for cleaning control rods, no effective cleaning could not be conducted and there was a possibility that obstacles may not be recovered. Then, there are disposed a first pump for supplying pressurized water, a spray nozzle for forming a swirling flow in a control rod guide tube, a second pump for pressurizing water introduced by a sucking pipeline and a collecting device for recovering obstacles intruding to water from the second pump. The pressurized water supplied from the first pump is introduced to a head passing through a blowing pipe and jetted from the spray nozzle to the control rod guide tube. In this case, a swirling stream occurs and obstacles in the control guide tube are mixed into water. The water containing the obstacles passes from the sucking port through a pipeline, introduced to the second pump and recovered to the collecting device. Since there is no water staying portion upon cleaning operation, the obstacles accumulating over the entire region of the bottom of the guide tube can be recovered reliably and efficiently. (N.H.)

Radioisotopic control and automation of food mills

International Nuclear Information System (INIS)

Pertsovskij, E.S.; Sakharov, Eh.V.; Dolinin, V.A.

1980-01-01

Domestic and foreign experience in application of radioisotope devices to process control in fool industry, is described. The diagrams of devices to block and account the production in systems of process monitoring and control are considered. The methods of determining chemical composition of substances are discussed, as sell as the devices used for those purposes and based on recording β-and γ-radiation absorption by substance. The methods for determining dust and smoke content in premises using radioisotope devices. Level indicators, moisture gages and densitimeters usedf ctol level humidity, density and concentration of food products in the process of production are described [ru

Feedwater control method and device therefor

International Nuclear Information System (INIS)

Nakahara, Mitsugu; Ichikawa, Yoshiaki; Ishii, Yoshikazu; Suzuki, Katsuyuki; Tanikawa, Naoshi; Mizuki, Fumio.

1997-01-01

The present invention provides a method of and a device for easily changing the constitution of feedwater systems without causing change in the water level of a reactor even when a plurality of feedwater systems have imbalance points. Namely, a feedwater control device comprises at least two feedwater systems capable of feeding water to tanks independently respectively and a controller capable of controlling water level in the tanks by controlling these feedwater systems. There is disposed a means for outputting gradually increasing driving signals to other feedwater systems, when the water level controller automatically controls one of the feedwater systems. There is also disposed a means for switching from automatic control for one of the feedwater systems to automatic control for the other feedwater system by a water level controller when the other feedwater system is in a stable operation region. As a result, entire feedwater flow rate is not temporarily changed and the water level in the tanks can be maintained constant. (N.H.)

Plasma control device

International Nuclear Information System (INIS)

Takase, Haruhiko.

1987-01-01

Purpose: To obtain the optimum controllability for the plasmas and the thermonuclear device by selectively executing control operation for proportion, integration and differentiation (PID) by first and second controllers respectively based on selection instruction signals. Constitution: Deviation between a vertical direction equilibrium position: Zp as the plasma status amount measured in a measuring section and an aimed value Zref thereof is inputted to a first PID selection controller. The first controller selectively executes one of the PID control operations in accordance with the first selection signal instruction instructed by a PID control operation instruction circuit. Further, Zp is also inputted to a second PID selection controller, which selectively executes one of the PID control operations in accordance with the second selection instruction signal in the same manner as in the first controller. The deviation amount u between operations signals u1 and u2 from the first and second PID selection controllers is inputted to a power source to thereby supply a predetermined current value to control coils that generate equilibrium magnetic fields for making the vertical direction equilibrium position of plasmas constant. (Kamimura, M.)

A safety control device for detecting undesirable conditions

Energy Technology Data Exchange (ETDEWEB)

1974-09-26

The invention relates to safety control devices. It deals with a device adapted to transmit a warning signal and to the detection of an undesirable condition in an associated apparatus, said device comprising switching means comprising transistors mounted in a reaction path, feeding means for opening the switching means whenever an undesirable condition has been detected by sensors, whereby an oscillator is caused to stop oscillating, and an outlet device controlled by the oscillator stoppage. This can be applied to the supervision of nuclear reactor.

Plasma particle lofting : experimental investigation of dust removal force

NARCIS (Netherlands)

Heijmans, L.C.J.; Nijdam, S.

2015-01-01

Dust is everywhere. Sometimes it's harmless, but sometimes it needs to be removed. Especially in modern optical machinery, dust control can be of vital importance. In this research we look at dust on a surface. We focus on the behaviour under influence of a plasma. The dust particles will stick to a

Inhalation of road dust by human subjects.

Science.gov (United States)

Takishima, T; Nakamura, M; Sasaki, M; Miyano, M; Yamaya, M; Sasaki, H

1987-11-01

We measured pneumomagnetic field strength (PMFS) in 42 healthy control subjects living in districts of Northern Japan with low levels of road dust pollution and in 39 healthy subjects living in areas with high levels of road dust pollution. Suspended road dust produced by studded tires increases from 30 micrograms/m3 during the summer season to levels as high as 400 micrograms/m3 during the snow season in the downtown areas of Sendai, Japan. Road dust retained in the lungs, containing 3% iron, was magnetized from the surface of the chest wall, and PMFS was measured. Three to 5 sequential PMFS measurements were made in each subject in March and October of 1984 and 1985, and in March 1986. The PMFS in control subjects in March 1984 was 37 +/- 14 pico-Tesla (mean +/- SD) and did not significantly differ from the PMFS in October 1984 or that in March 1985. In March 1984, the PMFS of the subjects in highly polluted areas was 95 +/- 100 pico-Tesla (mean +/- SD) and was significantly higher than that of control subjects (p less than 0.01) and subsequently decreased in March 1985 and in March 1986, corresponding to a decrease in suspended road dust brought about by a campaign to eliminate the use of studded tires. Our findings suggest that some road dust caused by studded tires is retained in the lungs.

Wind turbine remote control using Android devices

Science.gov (United States)

Rat, C. L.; Panoiu, M.

2018-01-01

This paper describes the remote control of a wind turbine system over the internet using an Android device, namely a tablet or a smartphone. The wind turbine workstation contains a LabVIEW program which monitors the entire wind turbine energy conversion system (WECS). The Android device connects to the LabVIEW application, working as a remote interface to the wind turbine. The communication between the devices needs to be secured because it takes place over the internet. Hence, the data are encrypted before being sent through the network. The scope was the design of remote control software capable of visualizing real-time wind turbine data through a secure connection. Since the WECS is fully automated and no full-time human operator exists, unattended access to the turbine workstation is needed. Therefore the device must not require any confirmation or permission from the computer operator in order to control it. Another condition is that Android application does not have any root requirements.

Device Configuration Handler for Accelerator Control Applications at Jefferson Lab

International Nuclear Information System (INIS)

Bickley, Matt; Chevtsov, P.; Larrieu, T.

2003-01-01

The accelerator control system at Jefferson Lab uses hundreds of physical devices with such popular instrument bus interfaces as Industry Pack (IPAC), GPIB, RS-232, etc. To properly handle all these components, control computers (IOCs) must be provided with the correct information about the unique memory addresses of the used interface cards, interrupt numbers (if any), data communication channels and protocols. In these conditions, the registration of a new control device in the control system is not an easy task for software developers. Because the device configuration is distributed, it requires the detailed knowledge about not only the new device but also the configuration of all other devices on the existing system. A configuration handler implemented at Jefferson Lab centralizes the information about all control devices making their registration user-friendly and very easy to use. It consists of a device driver framework and the device registration software developed on the basis of ORACLE database and freely available scripting tools (perl, php)

GPS User Devices Parameter Control Methods

OpenAIRE

Klūga, A; Kuļikovs, M; Beļinska, V; Zeļenkovs, A

2007-01-01

In our day’s wide assortment of GPS user devices is manufacture. How to verify that parameters of the real device corresponds to parameters that manufacture shows. How to verify that parameters have not been changed during the operation time. The last one is very important for aviation GPS systems, which must be verified before the flight, but the values of parameter in time of repair works. This work analyses GPS user devices parameters control methods.

Selection of input devices and controls for modern process control consoles

International Nuclear Information System (INIS)

Hasenfuss, O.; Zimmermann, R.

1975-06-01

In modern process control consoles man-machine communication is realized more and more by computer driven CRT displays, the most efficient communication system today. This paper describes the most important input devices and controls for such control consoles. A certain number of facts are given, which should be considered during the selection. The aptitude of the described devices for special tasks is discussed and recommendations are given for carrying out a selection. (orig.) [de

Dust particle removal efficiency of a venturi scrubber

International Nuclear Information System (INIS)

Ali, Majid; Yan, Changqi; Sun, Zhongning; Gu, Haifeng; Mehboob, Khurram

2013-01-01

Highlights: ► Experimental and theoretical study of dust removal efficiency in venturi scrubber. ► Dust removal efficiency 99.5% is achieved at throat gas velocity 220 m/s. ► Results obtained from mathematical model concur well with experimental results. - Abstract: The venturi scrubber is one of the most efficient gas cleaning devices to remove the contaminated particles from gaseous stream during severe accident in nuclear power plant. This study is focused on the dust particle removal efficiency of the venturi scrubber experimentally and theoretically. The venturi scrubber encapsulates the dust particles in petite water droplets flowing into it. The water injected into the scrubber is in the form of water film. The study investigates the removal efficiency of venturi scrubber for throat gas velocities of 130, 165 and 200 m/s and liquid flow rates 0.3–1 m 3 /h, whereas dust concentration ranges between 0.1 and 1 g/m 3 . The hydrophobic titanium dioxide (TiO 2 ) particles having density 4.23 g/cm 3 and mean diameter of 1 μm are used as dust particles in this research. Filtration technique is used to measure the concentration of dust particles at inlet and outlet. Experimental results show that the removal efficiency is higher with the increase of throat gas velocity and liquid flow rate. A mathematical model is employed for the verification of experimental results. The model concurs well with the experimental results

Device for controlling gas recovery

International Nuclear Information System (INIS)

Ichioka, Atsushi.

1976-01-01

Purpose: To provide a controlling device for UF 6 gas recovery device, which can increase working efficiency and to discriminate normality and abnormality of the recovery device. Constitution: The gas recovery device comprises a plurality of traps, which are connected in series. The UF 6 gas is introduced into the first trap where adsorbing work is taken place to accumulate UF 6 gases, and the UF 6 gases partly flow into the succeeding trap. Even in this trap, when the adsorbing work begins, the succeeding trap is operated in series fashion. In this manner, two traps are continuously operated to recover the gases while performing the steps of adsorbing, waiting and regenerating in that order. The switching operation of the aforesaid steps is accomplished on the basis of concentration of the UF 6 detected between two traps, which are continuously driven. (Kamimura, M.)

42 CFR 84.1141 - Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

Science.gov (United States)

2010-10-01

... mist respirators designed for respiratory protection against fumes of various metals having an air... HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist....1141 Isoamyl acetate tightness test; dust, fume, and mist respirators designed for respiratory...

Field evaluation of air-blocking shelf for dust control on blasthole drills

Energy Technology Data Exchange (ETDEWEB)

J. Drew Potts; W. Randolph Reed [Office of Mine Safety and Health Research, NIOSH, Pittsburgh, PA (United States). Dust Control, Ventilation, and Toxic Substance Branch

2011-03-15

In previous studies, an air-blocking shelf has been shown to be successful in reducing respirable dust leakage from the drill shroud in a laboratory setting. Dust reductions of up to 81% were achieved with the shelf under operating conditions consisting of a 1.9:1 collector-to-bailing airflow ratio and a 5.1-cm gap between the shroud and ground. Recent research focused on evaluating the shelf on two actual operating blasthole drills, in much more severe environments. In the field, the shelf reduced dust levels in the areas surrounding one operating blasthole drill by 70%. Dust reductions measured in the immediate vicinity of the shroud were reduced by 66% at one mine and 81% at the other mine. These field tests confirm that the air-blocking shelf is useful for reducing respirable dust generation from blasthole drills.

Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

Directory of Open Access Journals (Sweden)

Ivković Sanja

2014-01-01

Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

Method and device for controlling radiation

International Nuclear Information System (INIS)

Wilhelm, G.M.

1979-01-01

A device which will control radiation emanating from colour television sets is described. It consists of two transparent plates the same size as a television screen, with a thin layer of transparent mineral oil sealed between them. The device may be installed by the manufacturer or bought separately and installed by the user. (LL)

Control system and method for prosthetic devices

Science.gov (United States)

Bozeman, Richard J., Jr. (Inventor)

1992-01-01

A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the movable body part through the full-shrug position of the movable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the movable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective movable prosthesis device and its sub-prosthesis.

Role of the convergence zone over West Africa in controlling Saharan mineral dust load and transport in the boreal summer

Directory of Open Access Journals (Sweden)

Owen M. Doherty

2014-07-01

Full Text Available During summer, large amounts of mineral dust are emitted and transported from North Africa over the tropical North Atlantic towards the Caribbean with the exact quantity varying greatly from year to year. Much effort has been made to explain the variability of summer season mineral dust load, for example, by relating dust variability to teleconnection indices such as ENSO and the NAO. However, only weak relationships between such climate indices and the abundance of mineral dust have been found. In this work, we demonstrate the role of the near-surface convergence zone over West Africa in controlling dust load and transport of mineral dust. We apply the ‘Center of Action’ approach to obtain indices that quantify the movement and strength of the convergence zone using NCEP/NCAR Reanalysis data. The latitudinal position of the convergence zone is significantly correlated with the quantity of mineral dust at Barbados over the period 1965–2003 (r=−0.47. A southward displacement of the convergence zone is associated with both increased near-surface flow and decreased precipitation over the dust source regions of the southern Saharan desert, Sahel and Lake Chad. This in turn reduces soil moisture and vegetation, furthering the potential for dust emission. In contrast, the intensity of the convergence zone is not correlated with dust concentration at Barbados. We conclude that the coupling of changes in near-surface winds with changes in precipitation in source regions driven by a southward movement of the convergence zone most directly influence dust load at Barbados and over the tropical North Atlantic during summer.

Dust exposure and pneumoconiosis in a South African pottery. 1. Study objectives and dust exposure.

Science.gov (United States)

Rees, D; Cronje, R; du Toit, R S

1992-07-01

Dust exposure and pneumoconiosis were investigated in a South African pottery that manufactured wall tiles and bathroom fittings. This paper describes the objectives of the investigation and presents dust measurement data. x Ray diffraction showed that the clays used by the pottery had a high quartz content (range 58%-23%, mean 38%). Exposure to respirable dust was measured for 43 workers and was highest (6.6 mg/m3) in a bathroom fitting fettler. Quartz concentrations in excess of 0.1 mg/m3 were found in all sections of the manufacturing process from slip production to biscuit firing and sorting. The proportion of quartz in the respirable dust of these sections was 24% to 33%. This is higher than is usually reported in English potteries. Four hundred and six (80%) of the 509 workers employed at the pottery were potentially at risk of occupational lung disease. The finding of large numbers of pottery workers exposed to unacceptable dust concentrations is not surprising as poor dust control was found in all six wall tile and sanitary ware factories surveyed by the National Centre for Occupational Health between 1973 and 1989. Dust related occupational disease can be expected in potters for many years to come.

Effects of dust on forest tree health in Zagros oak forests.

Science.gov (United States)

Moradi, A; Taheri Abkenar, K; Afshar Mohammadian, M; Shabanian, N

2017-10-10

Dust is one of the most devastating factors for the environment threatening all animal and plant species. In many regions, the ecological and economic impact of microdust on scarce species is critical. In the western region of Iran, the Zagros forests have been exposed to dust storms for many years. In this study, the effect of dust on oak trees, the most important trees of Zagros forests, is investigated. For this purpose, 3-year-old seedlings of three species of oak trees under natural conditions were exposed to dust during spring and summer months. Seedlings were divided into two groups; one group was assigned as dust treatment and the other as control that the control group washed regularly to remove dust. Anatomical characteristics of leaves and dust deposits on leaves during the study period were examined by scanning electron microscope (SEM). The rate of photosynthesis and gas exchange in control and treated plants was examined by IRGA, LCI. SEM images showed that stomata structure, trichome density, and epicuticular waxes of leaves are different in all three species. This difference in micromorphology of species influences the effects of dust deposited on the leaves. A comparison of leaf species images in control and dust treatment showed that in dust treatment the percentage of stomata blocked by dust in three species (per unit area) of Quercus infectoria, Q. libni, and Q. brantii were 61/6, 48/4, and 38/1%, respectively. The results of leaf gas exchange investigation indicated that stomatal occlusion by dust had a negative impact on the examined parameters of three oak species (P ≤ 0.01). Thus, gas exchange and photosynthetic rates of the treated species were significantly reduced. The results of both parts of the study showed the vulnerability of the three species to dust as Q. infectoria > Q. libni > Q. brantii. Therefore, based on these findings, dust can disrupt the physiological activities of the studied species and the continuation of the

Wearable Device Control Platform Technology for Network Application Development

Directory of Open Access Journals (Sweden)

Heejung Kim

2016-01-01

Full Text Available Application development platform is the most important environment in IT industry. There are a variety of platforms. Although the native development enables application to optimize, various languages and software development kits need to be acquired according to the device. The coexistence of smart devices and platforms has rendered the native development approach time and cost consuming. Cross-platform development emerged as a response to these issues. These platforms generate applications for multiple devices based on web languages. Nevertheless, development requires additional implementation based on a native language because of the coverage and functions of supported application programming interfaces (APIs. Wearable devices have recently attracted considerable attention. These devices only support Bluetooth-based interdevice communication, thereby making communication and device control impossible beyond a certain range. We propose Network Application Agent (NetApp-Agent in order to overcome issues. NetApp-Agent based on the Cordova is a wearable device control platform for the development of network applications, controls input/output functions of smartphones and wearable/IoT through the Cordova and Native API, and enables device control and information exchange by external users by offering a self-defined API. We confirmed the efficiency of the proposed platform through experiments and a qualitative assessment of its implementation.

Occupational dust exposure and head and neck squamous cell carcinoma risk in a population-based case–control study conducted in the greater Boston area

International Nuclear Information System (INIS)

Langevin, Scott M; McClean, Michael D; Michaud, Dominique S; Eliot, Melissa; Nelson, Heather H; Kelsey, Karl T

2013-01-01

Head and neck cancers account for an estimated 549,000 global cancer diagnoses each year. While tobacco use, alcohol consumption, and HPV16 infection are considered to be the major risk factors for this disease, occupational risk factors, including exposure to asbestos, have also been described, although dust exposures other than asbestos have been historically understudied. We have investigated the relationship between occupational exposures to five types of dusts, including sawdust, concrete dust, leather dust, metal dust, and chimney soot, and head and neck squamous cell carcinomas (HNSCC) in the greater Boston area. We report findings from a population-based case–control study involving 951 incident HNSCC cases and 1193 controls, frequency matched on age (±3 years), sex, and town/neighborhood of residence. Multivariable logistic regression was used to assess the association between occupational exposure to each type of dust and HNSCC, overall and by primary tumor site. After adjusting for age, sex, race, smoking, alcohol consumption, education, and HPV16 serology, laryngeal carcinoma risk increased for each decade of occupational exposure to sawdust (OR = 1.2, 95% CI: 1.0, 1.3) and metal dust (OR = 1.2, 95% CI: 1.0, 1.4); and HNSCC risk increased for each decade of occupational leather dust exposure (OR = 1.5, 95% CI: 1.2, 1.9). We have provided evidence for an association between occupational sawdust and metal dust and laryngeal squamous cell carcinoma, and leather dust and HNSCC, with increasing risk with longer duration at the exposed occupation

Occupational dust exposure and head and neck squamous cell carcinoma risk in a population-based case-control study conducted in the greater Boston area.

Science.gov (United States)

Langevin, Scott M; McClean, Michael D; Michaud, Dominique S; Eliot, Melissa; Nelson, Heather H; Kelsey, Karl T

2013-12-01

Head and neck cancers account for an estimated 549,000 global cancer diagnoses each year. While tobacco use, alcohol consumption, and HPV16 infection are considered to be the major risk factors for this disease, occupational risk factors, including exposure to asbestos, have also been described, although dust exposures other than asbestos have been historically understudied. We have investigated the relationship between occupational exposures to five types of dusts, including sawdust, concrete dust, leather dust, metal dust, and chimney soot, and head and neck squamous cell carcinomas (HNSCC) in the greater Boston area. We report findings from a population-based case-control study involving 951 incident HNSCC cases and 1193 controls, frequency matched on age (±3 years), sex, and town/neighborhood of residence. Multivariable logistic regression was used to assess the association between occupational exposure to each type of dust and HNSCC, overall and by primary tumor site. After adjusting for age, sex, race, smoking, alcohol consumption, education, and HPV16 serology, laryngeal carcinoma risk increased for each decade of occupational exposure to sawdust (OR = 1.2, 95% CI: 1.0, 1.3) and metal dust (OR = 1.2, 95% CI: 1.0, 1.4); and HNSCC risk increased for each decade of occupational leather dust exposure (OR = 1.5, 95% CI: 1.2, 1.9). We have provided evidence for an association between occupational sawdust and metal dust and laryngeal squamous cell carcinoma, and leather dust and HNSCC, with increasing risk with longer duration at the exposed occupation. © 2013 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Object oriented programming techniques applied to device access and control

International Nuclear Information System (INIS)

Goetz, A.; Klotz, W.D.; Meyer, J.

1992-01-01

In this paper a model, called the device server model, has been presented for solving the problem of device access and control faced by all control systems. Object Oriented Programming techniques were used to achieve a powerful yet flexible solution. The model provides a solution to the problem which hides device dependancies. It defines a software framework which has to be respected by implementors of device classes - this is very useful for developing groupware. The decision to implement remote access in the root class means that device servers can be easily integrated in a distributed control system. A lot of the advantages and features of the device server model are due to the adoption of OOP techniques. The main conclusion that can be drawn from this paper is that 1. the device access and control problem is adapted to being solved with OOP techniques, 2. OOP techniques offer a distinct advantage over traditional programming techniques for solving the device access problem. (J.P.N.)

Comparative study of the characteristics of some suction devices for gas sampling applications

International Nuclear Information System (INIS)

Donguy, R.; Drouet, J.

1959-06-01

Gas sampling (used to determine the characteristics of dusts or aerosols contained in a gas) needs a suction device. In order to select the right device and the right conditions of use, the characteristics and performances of various suction devices (helicoidal and centrifugal aspirators, air pumps, volumetric pumps) have been experimentally measured: flow rate, head loss, sampling volume and duration, aerosol and dust concentration, gas density, nature of the gas, suction circuit configuration, etc

Climatic controls of the interannual to decadal variability in Saudi Arabian dust activity: Towards the development of a seasonal prediction tool

Science.gov (United States)

Yu, Y.; Notaro, M.; Liu, Z.; Alkolibi, F.; Fadda, E.; Bakhrjy, F.

2013-12-01

Atmospheric dust significantly influences the climate system, as well as human life in Saudi Arabia. Skillful seasonal prediction of dust activity with climatic variables will help prevent some negative social impacts of dust storms. Yet, the climatic regulators on Saudi Arabian dust activity remain largely unaddressed. Remote sensing and station observations show consistent seasonal cycles in Saudi Arabian dust activity, which peaks in spring and summer. The climatic controls on springtime and summertime Saudi Arabian dust activity during 1975-2010 are studied using observational and reanalysis data. Empirical Orthogonal Function (EOF) of the observed Saudi Arabian dust storm frequency shows a dominant homogeneous pattern across the country, which has distinct interannual and decadal variations, as revealed by the power spectrum. Regression and correlation analyses reveal that Saudi Arabian dust activity is largely tied to precipitation on the Arabian Peninsula in spring and northwesterly (Shamal) wind in summer. On the seasonal-interannual time scale, warm El Niño-Southern Oscillation (ENSO) phase (El Niño) in winter-to-spring inhibits spring dust activity by increasing the precipitation over the Rub'al Khali Desert, a major dust source region on the southern Arabian Peninsula; warm ENSO and warm Indian Ocean Basin Mode (IOBM) in winter-to-spring favor less summer dust activity by producing anomalously low sea-level pressure over eastern north Africa and Arabian Peninsula, which leads to the reduced Shamal wind speed. The decadal variation in dust activity is likely associated with the Atlantic Multidecadal Oscillation (AMO), which impacts Sahel rainfall and North African dust, and likely dust transport to Saudi Arabia. The Pacific Decadal Oscillation (PDO) and tropical Indian Ocean SST also have influence on the decadal variation in Saudi Arabian dust activity, by altering precipitation over the Arabian Peninsula and summer Shamal wind speed. Using eastern

Detection device for control rod scram

International Nuclear Information System (INIS)

Ishiyama, Satoshi.

1989-01-01

The device of the present invention comprises a control rod dropping separately from a control rod driving mechanism main body, a following tube falling separately accompanying therewith and a guide tube for guiding the dropping of the control rod and the following tube. Further, rare earth permanent magnets are embedded with the pole being axially oriented in the following tube and bobbins each mounted with an inner flange made of high magnetic permeability material are disposed to the guide tube. Coils are wound in the bobbin. In this control rod scram detection device, since magnetic fluxes can effectively be supplied to the coils, it is possible to obtain stable and highly reliable scram detection signals. Further, since the coils and the bobbins can be manufactured separately from the guide tube, their assemblies can be tested independently from the guide tube. (K.M.)

Testing of a Plasmadynamic Hypervelocity Dust Accelerator

Science.gov (United States)

Ticos, Catalin M.; Wang, Zhehui; Dorf, Leonid A.; Wurden, G. A.

2006-10-01

A plasmadynamic accelerator for microparticles (or dust grains) has been designed, built and tested at Los Alamos National laboratory. The dust grains are expected to be accelerated to hypervelocities on the order of 1-30 km/s, depending on their size. The key components of the plasmadynamic accelerator are a coaxial plasma gun operated at 10 kV, a dust dispenser activated by a piezoelectric transducer, and power and remote-control systems. The coaxial plasma gun produces a high density (10^18 cm-3) and low temperature (˜ 1 eV) plasma in deuterium ejected by J x B forces, which provides drag on the dust particles in its path. Carbon dust particles will be used, with diameters from 1 to 50 μm. The plasma parameters produced in the coaxial gun are presented and their implication to dust acceleration is discussed. High speed dust will be injected in the National Spherical Torus Experiment to measure the pitch angle of magnetic field lines.

A proposed protocol for remote control of automated assessment devices

International Nuclear Information System (INIS)

Kissock, P.S.; Pritchard, D.A.

1996-01-01

Systems and devices that are controlled remotely are becoming more common in security systems in the US Air Force and other government agencies to provide protection of valuable assets. These systems reduce the number of needed personnel while still providing a high level of protection. However, each remotely controlled device usually has its own communication protocol. This limits the ability to change devices without changing the system that provides the communications control to the device. Sandia is pursuing a standard protocol that can be used to communicate with the different devices currently in use, or may be used in the future, in the US Air Force and other government agencies throughout the security community. Devices to be controlled include intelligent pan/tilt mounts, day/night video cameras, thermal imaging cameras, and remote data processors. Important features of this protocol include the ability to send messages of varying length, identify the sender, and more importantly, control remote data processors. This paper describes the proposed public domain protocol, features, and examples of use. The authors hope to elicit comments from security technology developers regarding format and use of remotely controlled automated assessment devices

Dust remobilization in fusion plasmas under steady state conditions

NARCIS (Netherlands)

Tolias, P.; Ratynskaia, S.; de Angeli, M.; De Temmerman, G.; Ripamonti, D.; Riva, G.; I. Bykov,; Shalpegin, A.; Vignitchouk, L.; Brochard, F.; Bystrov, K.; Bardin, S.; Litnovsky, A.

2016-01-01

The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. The main theoretical aspects of remobilization in fusion devices under steady state conditions are analyzed. In particular, the dominant role of adhesive forces is highlighted and generic

Characterization of dust particles produced in an all-tungsten wall tokamak and potentially mobilized by airflow

Energy Technology Data Exchange (ETDEWEB)

Rondeau, A., E-mail: anthony.rondeau@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, 91192 Gif-sur-Yvette (France); Peillon, S.; Roynette, A.; Sabroux, J.-C.; Gelain, T.; Gensdarmes, F. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES, SCA, 91192 Gif-sur-Yvette (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Grisolia, C. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Chassefière, E. [Laboratoire Géosciences Paris Sud (GEOPS), UMR 8148, Université Paris Sud, 91403 Orsay Cedex (France)

2015-08-15

At the starting of the shutdown of the AUG (ASDEX Upgrade: Axially Symmetric Divertor EXperiment) German tokamak, we collected particles deposited on the divertor surfaces by means of a dedicated device called “Duster Box”. This device allows to collect the particles using a controlled airflow with a defined shear stress. Consequently, the particles collected correspond to a potentially mobilizable fraction, by an airflow, of deposited dust. A total of more than 70,000 tungsten particles was, analysed showing a bimodal particle size distribution with a mode composed of flakes at 0.6 μm and a mode composed of spherical particles at 1.8 μm.

Method for installing a control rod driving device in a reactor

International Nuclear Information System (INIS)

Sato, Haruo; Watanabe, Masatoshi.

1975-01-01

Object: To install a device using a wire rope, including individually moving up and down a control rod and a control rod driving device thereby enabling to install them within a low house and to reduce time required for installing operation. Structure: The control rod is temporarily attached to a support structure for the control rod driving device, the control rod driving device is suspended on a crane positioned upwardly of the support structure, a rope connected to the control rod driving device is connected to the control rod, a sagged portion of the rope is then wound about a rotary cylinder, the control rod is disconnected from its temporary attachment, and the wound rope is wound back while the rotary cylinder is rotated to move down the control rod. After the rope has been released from the rotary cylinder, the control rod driving device is moved down by the crane. (Kamimura, M.)

DustEM: Dust extinction and emission modelling

Science.gov (United States)

Compiègne, M.; Verstraete, L.; Jones, A.; Bernard, J.-P.; Boulanger, F.; Flagey, N.; Le Bourlot, J.; Paradis, D.; Ysard, N.

2013-07-01

DustEM computes the extinction and the emission of interstellar dust grains heated by photons. It is written in Fortran 95 and is jointly developed by IAS and CESR. The dust emission is calculated in the optically thin limit (no radiative transfer) and the default spectral range is 40 to 108 nm. The code is designed so dust properties can easily be changed and mixed and to allow for the inclusion of new grain physics.

30 CFR 90.301 - Respirable dust control plan; approval by District Manager; copy to part 90 miner.

Science.gov (United States)

2010-07-01

... District Manager; copy to part 90 miner. 90.301 Section 90.301 Mineral Resources MINE SAFETY AND HEALTH... control plan; approval by District Manager; copy to part 90 miner. (a) The District Manager will approve... District Manager shall consider whether: (1) The respirable dust control measures would be likely to...

Simulation of dust production in ITER transient events

Energy Technology Data Exchange (ETDEWEB)

Pestchanyi, S. [Forschungszentrum Karlsruhe (Germany)

2007-07-01

The tritium retention problem is a critical issue for the tokamak ITER performance. Tritium is trapped in redeposited T-C layers and at the surface of carbon dust, where it is retained in form of various hydrocarbons. The area of dust surface and hence, the amount of tritium deposited on the surface depends on the dust amount and of the dust sizes. The carbon dust appears as a result of brittle destruction at the surface of the carbon fibre composite (CFC) which is now the reference armour material for the most loaded part of tokamak divertor. Stationary heat flux on the ITER divertor armour does not cause its brittle destruction and does not produce dust. However, according to the modern understanding of tokamak fusion devices performance, the most attractive regime of ITER operation is the ELMy H mode. This regime is associated with a repetitive short time increase of heat flux at the CFC divertor armour of 2-3 orders of magnitude over its stationary value during edge localized modes (ELMs). Under influence of these severe heat shocks CFC armour can crack due to the thermostress, producing a dust of carbon. Besides, a carbon dust produced during disruptions due to brittle destruction of the armour under influence of thermoshock. Most of the modern tokamaks do not produce the ELMs powerful enough to cause CFC brittle destruction at the divertor surface, except of very special regimes in JET. This is why the CFC erosion and dust production could be investigated now only theoretically and experimentally in plasma guns and electron beam facilities. Simulation of the CFC brittle destruction has been done using the code PEGASUS already developed and tested in FZK for simulation of erosion for ITER candidate materials under the heat shocks. After upgrades the code was used for simulation of the amount of carbon dust particles and of the distribution of their sizes. The code has been tested against available experimental data from the plasma gun MK-200UG and from the

Simulation of dust production in ITER transient events

International Nuclear Information System (INIS)

Pestchanyi, S.

2007-01-01

The tritium retention problem is a critical issue for the tokamak ITER performance. Tritium is trapped in redeposited T-C layers and at the surface of carbon dust, where it is retained in form of various hydrocarbons. The area of dust surface and hence, the amount of tritium deposited on the surface depends on the dust amount and of the dust sizes. The carbon dust appears as a result of brittle destruction at the surface of the carbon fibre composite (CFC) which is now the reference armour material for the most loaded part of tokamak divertor. Stationary heat flux on the ITER divertor armour does not cause its brittle destruction and does not produce dust. However, according to the modern understanding of tokamak fusion devices performance, the most attractive regime of ITER operation is the ELMy H mode. This regime is associated with a repetitive short time increase of heat flux at the CFC divertor armour of 2-3 orders of magnitude over its stationary value during edge localized modes (ELMs). Under influence of these severe heat shocks CFC armour can crack due to the thermostress, producing a dust of carbon. Besides, a carbon dust produced during disruptions due to brittle destruction of the armour under influence of thermoshock. Most of the modern tokamaks do not produce the ELMs powerful enough to cause CFC brittle destruction at the divertor surface, except of very special regimes in JET. This is why the CFC erosion and dust production could be investigated now only theoretically and experimentally in plasma guns and electron beam facilities. Simulation of the CFC brittle destruction has been done using the code PEGASUS already developed and tested in FZK for simulation of erosion for ITER candidate materials under the heat shocks. After upgrades the code was used for simulation of the amount of carbon dust particles and of the distribution of their sizes. The code has been tested against available experimental data from the plasma gun MK-200UG and from the

Air ionizer application for electrostatic discharge (ESD) dust removal in automotive painting industry

Science.gov (United States)

Yosri, M. H.; Muhamad, P.; Ismail, M. A.; Yatim, N. H. M.

2018-01-01

Dust and fiber have been identified among the highest contributor for the defect in automotive painting line with range from 40% to 50% of total defect breakdown. Eventually, those defects will effect on both visual appearance and also the performance of the parts. In addition, the significance of controlling dust in an assembly line is crucial in order to maintain the quality of the product, part performance yield and effect on workers’ health [1]. By considering the principle and technology applied in electronic clean room technology, the ionizer have been introduce to control dust contamination in automotive painting line. The first auto maker industry whom found the effectiveness of the clean room application to reduce the defect and production line downtime was Chrysler [2]. By doing so, it’s allowed the transmission plant to offer 50 000 mile guarantee on the transmission systems. The main objective of this research is to verify the effectiveness of ionizer device in order to reduce the rejection contribute by dust and fiber particle in the automotive painting line. Towards the main objective, a few sub areas will be explored, as a supporting factor to ensure the result gain from this study is solid and constructive. The experiment start by verifying the electrostatic value of the raw material (substrate) before and after the ionizer treatment. From here the correlation of the electrostatic value generated by the raw material that effect to production pass rate can be explored. At the meantime, the performance of the production pass rate after the ionizer treatment which related to the painted surface area can be determined.

Field trials of an electret based passive dust sampler in coal mines

Energy Technology Data Exchange (ETDEWEB)

Hemingway, M.A.; Brown, R.C.; Arthur, J. [Health and Safety Laboratory, Sheffield (United Kingdom)

1997-12-31

An electret-based passive dust sampler has been developed by the Health and Safety Laboratory, UK. The device consists of a small disc of electret (polymer holding a permanent electric charge) held between earthen plates, and it acts by attaching charged dust particles to itself. The device does not require a pump and its rate of sampling is independent of external air velocity, provided that the velocity exceeds a low limiting value. Experiments have been carried out in two coal mines. In each experiment two passive sampler were mounted alongside an MRE sampler at the statutory sampling point in the return roadway. Both passive samplers were mounted vertically but in one the plane of the electret was parallel to the air flow and in the other it was perpendicular. The result obtained from the first mine showed a good correlation between gravimetric estimates of dust concentration obtained with the passive samplers and respirable dust concentrations obtained with MRE. The correlation between the two sets of results at the second mine was not quite as good as those of the first, but was reasonable. In no instance was any significant difference observed between samples obtained from pairs of passive samples in different orientations. 8 refs., 5 figs., 2 tabs.

Wood-related occupations, wood dust exposure, and sinonasal cancer.

Science.gov (United States)

Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

1986-10-01

A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

A controlled intervention study concerning the effect of intended temperature rise on house dust mite load

DEFF Research Database (Denmark)

Sidenius, Kirsten E; Hallas, Thorkil E; Poulsen, Lars K.

2002-01-01

In epidemiological studies, increased indoor temperature--producing a lower relative humidity--is associated with low house dust mite (HDM) load. Twenty-eight dwellings were allocated for either intervention (12/15 completed) or control (11/13 completed). In the intervention group, participants w...

Reactor control device

International Nuclear Information System (INIS)

Kinoshita, Mitsuo.

1991-01-01

Heretofore, since the aimed value of a reactor power has been determined only based on the deviation between a temperature variation coefficient and the aimed value, it involves a problem that a region for finely determining a control constant is complicated. In view of the above, in the present invention, an approximate value of the aimed reactor power value is determined based on the aimed value for the temperature variation coefficient, then a compensation value for the aimed power value is determined based on the deviation between the temperature variation coefficient and the aimed value and, further, the aimed power value is determined based on the approximate value and the compensation value. Control elements are automatically operated so that the power follows the aimed value after determining the aimed value. Then, since the aimed reactor power value is controlled finely so that the responsiveness of the temperature variation coefficient is satisfactory and the temperature variation coefficient agrees with the aimed value, the stability for the control of temperature variation coefficient is satisfactory. That is, high performance control is enabled by a simple control algorithm to reduce the number of the steps for the design and the device control. (N.H.)

A magnetorheological fluid-based multifunctional haptic device for vehicular instrument controls

International Nuclear Information System (INIS)

Han, Young-Min; Kim, Chan-Jung; Choi, Seung-Bok

2009-01-01

This paper presents control performances of a magnetorheological (MR) fluid-based multifunctional haptic device which is applicable to vehicular instrument controls. By combining in-vehicle functions into a single device, the proposed haptic device can transmit various reflection forces for each comfort function to a driver without requiring the driver's visual attention. As a multifunctional haptic device, a MR knob is proposed in this work and then devised to be capable of both rotary and push motions with a single knob. Under consideration of the spatial limitations of vehicle dashboards, design parameters are optimally determined by finite element analysis, and the objective function is to maximize a relative control torque. The proposed haptic device is then manufactured, and in-vehicle comfort functions are constructed in a virtual environment which makes the functions to communicate with the haptic device. Subsequently, a feed-forward controller using torque/force maps is formulated for the force tracking control. Control performances such as reflection force of the haptic device are experimentally evaluated via the torque/force map-based feed-forward controller

Micro-Scalable Thermal Control Device

Science.gov (United States)

Moran, Matthew E. (Inventor)

2002-01-01

A microscalable thermal control module consists of a Stirling cycle cooler that can be manipulated to operate at a selected temperature within the heating and cooling range of the module. The microscalable thermal control module is particularly suited for controlling the temperature of devices that must be maintained at precise temperatures. It is particularly suited for controlling the temperature of devices that need to be alternately heated or cooled. The module contains upper and lower opposing diaphragms, with a regenerator region containing a plurality of regenerators interposed between the diaphragms. Gaps exist on each side of each diaphragm to permit it to oscillate freely. The gap on the interior side one diaphragm is in fluid connection with the gap on the interior side of the other diaphragm through regenerators. As the diaphragms oscillate working gas is forced through the regenerators. The surface area of each regenerator is sufficiently large to effectively transfer thermal energy to and from the working gas as it is passed through them. The phase and amplitude of the oscillations can be manipulated electronically to control the steady state temperature of the active thermal control surface, and to switch the operation of the module from cooling to heating, or vice versa. The ability of the microscalable thermal control module to heat and cool may be enhanced by operating a plurality of modules in series, in parallel, or in connection through a shared bottom layer.

Control system devices : architectures and supply channels overview.

Energy Technology Data Exchange (ETDEWEB)

Trent, Jason; Atkins, William Dee; Schwartz, Moses Daniel; Mulder, John C.

2010-08-01

This report describes a research project to examine the hardware used in automated control systems like those that control the electric grid. This report provides an overview of the vendors, architectures, and supply channels for a number of control system devices. The research itself represents an attempt to probe more deeply into the area of programmable logic controllers (PLCs) - the specialized digital computers that control individual processes within supervisory control and data acquisition (SCADA) systems. The report (1) provides an overview of control system networks and PLC architecture, (2) furnishes profiles for the top eight vendors in the PLC industry, (3) discusses the communications protocols used in different industries, and (4) analyzes the hardware used in several PLC devices. As part of the project, several PLCs were disassembled to identify constituent components. That information will direct the next step of the research, which will greatly increase our understanding of PLC security in both the hardware and software areas. Such an understanding is vital for discerning the potential national security impact of security flaws in these devices, as well as for developing proactive countermeasures.

Determinants of dust exposure in tunnel construction work.

Science.gov (United States)

Bakke, Berit; Stewart, Patricia; Eduard, Wijnand

2002-11-01

In tunnel construction work, dust is generated from rock drilling, rock bolting, grinding, scaling, and transport operations. Other important dust-generating activities are blasting rock and spraying wet concrete on tunnel walls for strength and finishing work. The aim of this study was to identify determinants of dust exposure in tunnel construction work and to propose control measures. Personal exposures to total dust, respirable dust, and alpha-quartz were measured among 209 construction workers who were divided into 8 job groups performing similar tasks: drill and blast workers, shaft drilling workers, tunnel boring machine workers, shotcreting operators, support workers, concrete workers, outdoor concrete workers, and electricians. Information on determinants was obtained from interviewing the workers, observation by the industrial hygienist responsible for the sampling, and the job site superintendent. Multivariate regression models were used to identify determinants associated with the dust exposures within the job groups. The geometric mean exposure to total dust, respirable dust, and alpha-quartz for all tunnel workers was 3.5 mg/m(3) (GSD = 2.6), 1.2 mg/m(3) (GSD = 2.4), and 0.035 mg/m(3) (GSD = 5.0), respectively. A total of 15 percent of the total dust measurements, 5 percent of the respirable dust, and 21 percent of the alpha-quartz exceeded the Norwegian OELs of 10 mg/m(3), 5 mg/m(3), and 0.1 mg/m(3), respectively. Job groups with highest geometric mean total dust exposure were shotcreting operators (6.8 mg/m(3)), tunnel boring machine workers (6.2 mg/m(3)), and shaft drilling workers (6.1 mg/m(3)). The lowest exposed groups to total dust were outdoor concrete workers (1.0 mg/m(3)), electricians (1.4 mg/m(3)), and support workers (1.9 mg/m(3)). Important determinants of exposure were job group, job site, certain tasks (e.g., drilling and scaling), the presence of a cab, and breakthrough of the tunnel. The use of ventilated, closed cabs appeared to be

Dust acoustic shock wave at high dust density

International Nuclear Information System (INIS)

Ghosh, Samiran; Sarkar, Susmita; Khan, Manoranjan; Avinash, K.; Gupta, M. R.

2003-01-01

Dust acoustic (DA) shock wave at high dust density, i.e., the dust electroacoustic (DEA) or dust Coulomb (DC) shock wave has been investigated incorporating the nonadiabatic dust charge variation. The nonlinear DEA (DC) shock wave is seen to be governed by the Korteweg-de Vries Burger equation, in which the Burger term is proportional to the nonadiabaticity generated dissipation. It is seen that the shock strength decreases but after reaching minimum, it increases as the dust space charge density |q d n d | increases and the shock strength of DA wave is greater than that of DEA (DC) wave. Moreover the DEA (DC) shock width increases appreciably with increase mass m i of the ion component of the dusty plasma but for DA shock wave the effect is weak

Automatic control device for the reduction of reactor power

International Nuclear Information System (INIS)

Sumida, Susumu; Mizuno, Hiroshi.

1982-01-01

Purpose: To early detect troubles in condensate pipeways and feedwater pipeways of BWR-type reactor. Constitution: Detectors are provided to a condensate pipe, a condensator, a low pressure condensate pump, a condensate desalting device and a high pressure condensate pump for constituting condensate pipeways, as well as to a feedwater heater, a feedwater pipe and a feedwater pump for constituting feedwater pipeways. Each of the detectors is connected by way of a lead wire to an abnormal detection and processing device. The abnormal detection and processing device, which are connected to a recycling control device, monitor the input from the detector and sends a control signal to the recycling control system upon calculation of a trouble signal from the detector. (Sekiya, K.)

Experimental Method for Measuring Dust Load on Surfaces in Rooms

DEFF Research Database (Denmark)

Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms, there is a n......A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions....

Evaluation of an Electrostatic Dust Removal System with Potential Application in Next-Step Fusion Devices

International Nuclear Information System (INIS)

Friesen, F.Q.L.; John, B.; Skinner, C.H.; Roquemore, A.L.; Calle, C.I.

2011-01-01

The ability to manage inventories of carbon, tritium, and high-Z elements in fusion plasmas depends on means for effective dust removal. A dust conveyor, based on a moving electrostatic potential well, was tested with particles of tungsten, carbon, glass and sand. A digital microscope imaged a representative portion of the conveyor, and dust particle size and volume distributions were derived before and after operation. About 10 mm3 volume of carbon and tungsten particles were moved in under 5 seconds. The highest driving amplitude tested of 3 kV was the most effective. The optimal driving frequency was 210 Hz (maximum tested) for tungsten particles, decreasing to below 60 Hz for the larger sand particles. Measurements of particle size and volume distributions after 10 and 100 cycles show the breaking apart of agglomerated carbon, and the change in particle distribution over short timescales (<1 s).

Cometary Dust

Science.gov (United States)

Levasseur-Regourd, Anny-Chantal; Agarwal, Jessica; Cottin, Hervé; Engrand, Cécile; Flynn, George; Fulle, Marco; Gombosi, Tamas; Langevin, Yves; Lasue, Jérémie; Mannel, Thurid; Merouane, Sihane; Poch, Olivier; Thomas, Nicolas; Westphal, Andrew

2018-04-01

This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.

Study on coal dust wettability measurement using cold briquetting technique

Energy Technology Data Exchange (ETDEWEB)

Li, M.; Xu, H.; Shu, X. [North China Institute of Science and Technology, Beijing (China). Department of Resource and Environmental Engineering

2008-12-15

Quantitative measuring of coal dust wettability is essential for the research and development of chemical coal dust suppressants in the field of dust control with wetting-agent-added water. The causes of low repeat rate and poor consistency in present lab testing of coal dust wettability are discussed. The influence of different briquetting pressure (from 0 to 6.5108 Pa) on the wet behavior of coal dust is investigated as a new way to quantitatively evaluate coal dust wettability. The study shows that there is a fairly high coincidence between the coal dust wettability data measured by the briquetting technique and the results gained from the lab dust suppression tests using an MCYZ apparatus designed by the authors. 9 refs., 8 figs., 2 tabs.

Power control device of an atomic power plant

International Nuclear Information System (INIS)

Ootsuka, Shiro; Ito, Takero.

1980-01-01

Purpose: To improve the power controllability of an atomic power plant by improving the controllability, response and stability of the recirculation flow rate. Constitution: The power control device comprises a power detector of the reactor, which detects and operates the reactor power from the thermal power, neutron flux or the process quantity controlling the same, and a deviation detector which seeks deviation between the power signal of the power detector and the power set value of the reactor or power station. By use of the power control device constituted in this manner, the core flow rate is regulated by the power signal of the deviation detector thereby to control the power. (Aizawa, K.)

Experimental study on effects of drilling parameters on respirable dust production during roof bolting operations.

Science.gov (United States)

Jiang, Hua; Luo, Yi; McQuerrey, Joe

2018-02-01

Underground coalmine roof bolting operators exhibit a continued risk for overexposure to airborne levels of respirable coal and crystalline silica dust from the roof drilling operation. Inhaling these dusts can cause coal worker's pneumoconiosis and silicosis. This research explores the effect of drilling control parameters, specifically drilling bite depth, on the reduction of respirable dust generated during the drilling process. Laboratory drilling experiments were conducted and results demonstrated the feasibility of this dust control approach. Both the weight and size distribution of the dust particles collected from drilling tests with different bite depths were analyzed. The results showed that the amount of total inhalable and respirable dust was inversely proportional to the drilling bite depth. Therefore, control of the drilling process to achieve proper high-bite depth for the rock can be an important approach to reducing the generation of harmful dust. Different from conventional passive engineering controls, such as mist drilling and ventilation approaches, this approach is proactive and can cut down the generation of respirable dust from the source. These findings can be used to develop an integrated drilling control algorithm to achieve the best drilling efficiency as well as reducing respirable dust and noise.

Optically controlled multiple switching operations of DNA biopolymer devices

International Nuclear Information System (INIS)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

2015-01-01

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

Optically controlled multiple switching operations of DNA biopolymer devices

Energy Technology Data Exchange (ETDEWEB)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2015-12-21

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

Highly tunable local gate controlled complementary graphene device performing as inverter and voltage controlled resistor.

Science.gov (United States)

Kim, Wonjae; Riikonen, Juha; Li, Changfeng; Chen, Ya; Lipsanen, Harri

2013-10-04

Using single-layer CVD graphene, a complementary field effect transistor (FET) device is fabricated on the top of separated back-gates. The local back-gate control of the transistors, which operate with low bias at room temperature, enables highly tunable device characteristics due to separate control over electrostatic doping of the channels. Local back-gating allows control of the doping level independently of the supply voltage, which enables device operation with very low VDD. Controllable characteristics also allow the compensation of variation in the unintentional doping typically observed in CVD graphene. Moreover, both p-n and n-p configurations of FETs can be achieved by electrostatic doping using the local back-gate. Therefore, the device operation can also be switched from inverter to voltage controlled resistor, opening new possibilities in using graphene in logic circuitry.

Ground calibration of DREAMS-H relative humidity device

Science.gov (United States)

Komu, M.; Genzer, M.; Nikkanen, T.; Schmidt, W.; Haukka, H.; Kemppinen, O.; Harri, A.-M.

2014-04-01

DREAMS (Dust Characterization, Risk Assessment and Environmental Analyzer on the Martian Surface) instrument suite is to be launched as part of ESA ExoMars 2016/Entry, Descent and Landing Demonstration Module (EDM). DREAMS consists of an environmental package for monitoring temperature, pressure, relative humidity, winds and dust opacity, as well as atmospheric electricity of Martian atmosphere. DREAMS instruments and scientific goals are described in [1]. Here we describe ground calibration of the relative humidity device, DREAMS-H, provided to DREAMS payload by Finnish Meteorological Institute and based on proprietary technology of Vaisala, Inc. Same kind of device is part of REMS instrument package onboard MSL Curiosity Rover [2][3].

A Computer-Controlled SEM-EDX Routine for Characterizing Respirable Coal Mine Dust

Directory of Open Access Journals (Sweden)

Victoria Johann-Essex

2017-01-01

Full Text Available A recent resurgence in coal workers’ pneumoconiosis (or “black lung” and concerns over other related respiratory illnesses have highlighted the need to elucidate characteristics of airborne particulates in occupational environments. A better understanding of particle size, aspect ratio, or chemical composition may offer new insights regarding causal factors of such illnesses. Scanning electron microscopy analysis using energy dispersive X-ray (SEM-EDX can be used to estimate these particle characteristics. If conducted manually, such work can be very time intensive, limiting the number of particles that can be analyzed. Moreover, potential exists for user bias in interpretation of EDX spectra. A computer-controlled (CC routine, on the other hand, can allow similar analysis at a much faster rate, increasing total particle counts and reproducibility of results. This paper describes a CCSEM-EDX routine specifically developed for analysis of respirable dust samples from coal mines. The routine is verified based on reliability of results obtained on samples of known materials, and reproducibility of results obtained on a set of 10 dust samples collected in the field. The characteristics of the field samples are also discussed with respect to mine occupational environments.

Device provides controlled gas leaks

Science.gov (United States)

Kami, S. K.; King, H. J.

1968-01-01

Modified palladium leak device provides a controlled release /leak/ of very small quantities of gas at low or medium pressures. It has no moving parts, requires less than 5 watts to operate, and is capable of releasing the gas either continuously or in pulses at adjustable flow rates.

The Mars Dust and Water Cycles: Investigating the Influence of Clouds on the Vertical Distribution and Meridional Transport of Dust and Water

Science.gov (United States)

Kahre, Melinda A.; Haberle, Robert M.; Hollingsworth, Jeffery L.; Brecht, Amanda S.; Urata, Richard A.

2015-11-01

The dust and water cycles are critical to the current Martian climate, and they interact with each other through cloud formation. Dust modulates the thermal structure of the atmosphere and thus greatly influences atmospheric circulation. Clouds provide radiative forcing and control the net hemispheric transport of water through the alteration of the vertical distributions of water and dust. Recent advancements in the quality and sophistication of both climate models and observations enable an increased understanding of how the coupling between the dust and water cycles (through cloud formation) impacts the dust and water cycles. We focus here on the effects of clouds on the vertical distributions of dust and water and how those vertical distributions control the net meridional transport of water. We utilize observations of temperature, dust and water ice from the Mars Climate Sounder (MCS) on the Mars Reconnaissance Orbiter (MRO) and the NASA ARC Mars Global Climate Model (MGCM) to show that the magnitude and nature of the hemispheric exchange of water during NH summer is sensitive to the vertical structure of the simulated aphelion cloud belt. Further, we investigate how clouds influence atmospheric temperatures and thus the vertical structure of the cloud belt. Our goal is to isolate and understand the importance of radiative/dynamic feedbacks due to the physical processes involved with cloud formation and evolution on the current climate of Mars.

The Mars Dust and Water Cycles: Investigating the Influence of Clouds on the Vertical Distribution and Meridional Transport of Dust and Water.

Science.gov (United States)

Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Brecht, A. S.; Urata, R.

2015-01-01

The dust and water cycles are critical to the current Martian climate, and they interact with each other through cloud formation. Dust modulates the thermal structure of the atmosphere and thus greatly influences atmospheric circulation. Clouds provide radiative forcing and control the net hemispheric transport of water through the alteration of the vertical distributions of water and dust. Recent advancements in the quality and sophistication of both climate models and observations enable an increased understanding of how the coupling between the dust and water cycles (through cloud formation) impacts the dust and water cycles. We focus here on the effects of clouds on the vertical distributions of dust and water and how those vertical distributions control the net meridional transport of water. We utilize observations of temperature, dust and water ice from the Mars Climate Sounder (MCS) on the Mars Reconnaissance Orbiter (MRO) and the NASA ARC Mars Global Climate Model (MGCM) to show that the magnitude and nature of the hemispheric exchange of water during NH summer is sensitive to the vertical structure of the simulated aphelion cloud belt. Further, we investigate how clouds influence atmospheric temperatures and thus the vertical structure of the cloud belt. Our goal is to isolate and understand the importance of radiative/dynamic feedbacks due to the physical processes involved with cloud formation and evolution on the current climate of Mars.

The Coupled Mars Dust and Water Cycles: Understanding How Clouds Affect the Vertical Distribution and Meridional Transport of Dust and Water.

Science.gov (United States)

Kahre, M. A.

2015-01-01

The dust and water cycles are crucial to the current Martian climate, and they are coupled through cloud formation. Dust strongly impacts the thermal structure of the atmosphere and thus greatly affects atmospheric circulation, while clouds provide radiative forcing and control the hemispheric exchange of water through the modification of the vertical distributions of water and dust. Recent improvements in the quality and sophistication of both observations and climate models allow for a more comprehensive understanding of how the interaction between the dust and water cycles (through cloud formation) affects the dust and water cycles individually. We focus here on the effects of clouds on the vertical distribution of dust and water, and how those vertical distributions control the net meridional transport of water. For this study, we utilize observations of temperature, dust and water ice from the Mars Climate Sounder (MCS) on the Mars Reconnaissance Orbiter (MRO) combined with the NASA ARC Mars Global Climate Model (MGCM). We demonstrate that the magnitude and nature of the net meridional transport of water between the northern and southern hemispheres during NH summer is sensitive to the vertical structure of the simulated aphelion cloud belt. We further examine how clouds influence the atmospheric thermal structure and thus the vertical structure of the cloud belt. Our goal is to identify and understand the importance of radiative/dynamic feedbacks due to the physical processes involved with cloud formation and evolution on the current climate of Mars.

Peach leaf responses to soil and cement dust pollution.

Science.gov (United States)

Maletsika, Persefoni A; Nanos, George D; Stavroulakis, George G

2015-10-01

Dust pollution can negatively affect plant productivity in hot, dry and with high irradiance areas during summer. Soil or cement dust were applied on peach trees growing in a Mediterranean area with the above climatic characteristics. Soil and cement dust accumulation onto the leaves decreased the photosynthetically active radiation (PAR) available to the leaves without causing any shade effect. Soil and mainly cement dust deposition onto the leaves decreased stomatal conductance, photosynthetic and transpiration rates, and water use efficiency due possibly to stomatal blockage and other leaf cellular effects. In early autumn, rain events removed soil dust and leaf functions partly recovered, while cement dust created a crust partially remaining onto the leaves and causing more permanent stress. Leaf characteristics were differentially affected by the two dusts studied due to their different hydraulic properties. Leaf total chlorophyll decreased and total phenol content increased with dust accumulation late in the summer compared to control leaves due to intense oxidative stress. The two dusts did not cause serious metal imbalances to the leaves, except of lower leaf K content.

Reactor power control device

International Nuclear Information System (INIS)

Doi, Kazuyori.

1981-01-01

Purpose: To automatically control the BWR type reactor power by simple and short-time searching the load pattern nearest to the required pattern at a nuclear power plant side. Constitution: The reactor power is automatically regulated by periodical modifying of coefficients fitting to a reactor core model, according as a required load pattern. When a load requirement pattern is given, a simulator estimates the total power change and the axial power distribution change from a xenon density change output calculated by a xenon dynamic characteristic estimating device, and a load pattern capable of being realized is searched. The amount to be recirculated is controlled on the basis of the load patteren thus searched, and the operation of the BWR type reactor is automatically controlled at the side of the nuclear power plant. (Kamimura, M.)

Dusty plasma phase in a steady state plasma device

International Nuclear Information System (INIS)

Liang Xiaoping; Zheng Jian; Ma Jinxiu; Liu Wangdong; Zhuang Ge; Xie Jinlin; Wang Congrong; Yu Changxuan

2000-01-01

A DC discharge dusty plasma device used for study of waves in dusty plasma is introduced. A dusty plasma column is produced with about 30 cm in length and about 8.4 cm in diameter. The electron saturation current of Langmuir probe is obviously decreasing while the dust grains are present in the plasma. The negative charge on dust grains is directly proportional to the rotation rate of the dispenser. And the dust grains carry up to 40% of the negative charges in the whole plasma

High-latitude dust in the Earth system

Science.gov (United States)

Bullard, Joanna E; Baddock, Matthew; Bradwell, Tom; Crusius, John; Darlington, Eleanor; Gaiero, Diego; Gasso, Santiago; Gisladottir, Gudrun; Hodgkins, Richard; McCulloch, Robert; NcKenna Neuman, Cheryl; Mockford, Tom; Stewart, Helena; Thorsteinsson, Throstur

2016-01-01

Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high-latitude (≥50°N and ≥40°S) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 km2 and contribute at least 80–100 Tg yr−1 of dust to the Earth system (~5% of the global dust budget); both are projected to increase under future climate change scenarios.

High Latitude Dust in the Earth System

Science.gov (United States)

Bullard, Joanna E.; Baddock, Matthew; Bradwell, Tom; Crusius, John; Darlington, Eleanor; Gaiero, Diego; Gasso, Santiago; Gisladottir, Gudrun; Hodgkins, Richard; McCulloch, Robert;

Medical Devices; Immunology and Microbiology Devices; Classification of the Assayed Quality Control Material for Clinical Microbiology Assays. Final order.

Science.gov (United States)

2017-07-27

The Food and Drug Administration (FDA, Agency, or we) is classifying the assayed quality control material for clinical microbiology assays into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the assayed quality control material for clinical microbiology assays' classification. The Agency is classifying the device into class II (special controls) to provide a reasonable assurance of safety and effectiveness of the device.

Environmental impacts of oil and gas brine applications for dust and ice control in New York : final report.

Science.gov (United States)

2016-04-01

Transportation agencies are required to treat roads for dust and ice control to ensure adequate safety for travelers. This is commonly achieved through application of solid and liquid chemicals. These materials can be conventional rock salt, brine fr...

Fipronil and its degradates in indoor and outdoor dust

Science.gov (United States)

Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Zaugg, S.D.; Burkhardt, M.R.

2009-01-01

Fipronil is a potent insecticide used for control of termites, fleas, roaches, ants, and other pests. We measured fipronil, fipronil sulfide, and desulfinyl fipronil concentrations in indoor and outdoor dust from 24 residences in Austin, Texas. At least one of these three fipronil compounds was detected in every sample. Fipronil accounted for most of the total fipronil (T-fipronil; fipronil+desulfinyl fipronil+fipronil sulfide), followed by desulfinyl fipronil and fipronil sulfide. Nineteen of 24 samples of indoor dust had T-fipronil concentrations less than 270 ??g/kg; the remaining five had concentrations from 1320 to 14,200 ??g/kg. All three of the residences with a dog on which a flea-control product containing fipronil was used were among the five residences with elevated fipronil concentrations. In outdoor dust, all concentrations of T-fipronil were less than 70??g/kg with one exception (430??g/kg). For every residence, the concentration of T-fipronil in indoor dust exceeded that in outdoor dust, and the median concentration of T-fipronil was 15 times higher indoors than outdoors.

Implementation of Adaptive Digital Controllers on Programmable Logic Devices

Science.gov (United States)

Gwaltney, David A.; King, Kenneth D.; Smith, Keary J.; Monenegro, Justino (Technical Monitor)

2002-01-01

Much has been made of the capabilities of FPGA's (Field Programmable Gate Arrays) in the hardware implementation of fast digital signal processing. Such capability also makes an FPGA a suitable platform for the digital implementation of closed loop controllers. Other researchers have implemented a variety of closed-loop digital controllers on FPGA's. Some of these controllers include the widely used proportional-integral-derivative (PID) controller, state space controllers, neural network and fuzzy logic based controllers. There are myriad advantages to utilizing an FPGA for discrete-time control functions which include the capability for reconfiguration when SRAM-based FPGA's are employed, fast parallel implementation of multiple control loops and implementations that can meet space level radiation tolerance requirements in a compact form-factor. Generally, a software implementation on a DSP (Digital Signal Processor) or microcontroller is used to implement digital controllers. At Marshall Space Flight Center, the Control Electronics Group has been studying adaptive discrete-time control of motor driven actuator systems using digital signal processor (DSP) devices. While small form factor, commercial DSP devices are now available with event capture, data conversion, pulse width modulated (PWM) outputs and communication peripherals, these devices are not currently available in designs and packages which meet space level radiation requirements. In general, very few DSP devices are produced that are designed to meet any level of radiation tolerance or hardness. The goal of this effort is to create a fully digital, flight ready controller design that utilizes an FPGA for implementation of signal conditioning for control feedback signals, generation of commands to the controlled system, and hardware insertion of adaptive control algorithm approaches. An alternative is required for compact implementation of such functionality to withstand the harsh environment

Dust Measurements in Tokamaks

International Nuclear Information System (INIS)

Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

2008-01-01

Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 (micro)m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics

Spherical cauliflower-like carbon dust formed by interaction between deuterium plasma and graphite target and its internal structure

Energy Technology Data Exchange (ETDEWEB)

Ohno, N. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)], E-mail: ohno@ees.nagoya-u.ac.jp; Yoshimi, M. [Department of Energy Engineering and Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tokitani, M. [National Institute for Fusion Science, Oroshi 322-6, Toki 509-5292 (Japan); Takamura, S. [Department of Electronics, Aichi Institute of Technology, Yakusa-cho, Toyota 470-0392 (Japan); Tokunaga, K.; Yoshida, N. [Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2009-06-15

Simulated experiments to produce carbon dust particles with cauliflower structure have been performed in a liner plasma device, NAGDIS-II by exposing high density deuterium plasma to a graphite sample (IG-430U). Formation of carbon dust depends on the surface temperature and the incident ion energy. At a surface temperature 600-700 K, a lot of isolated spherical dust particles are observed on the graphite target. The internal structure of an isolated dust particle was observed with Focused Ion Beam (FIB) system and Transmission Electron Microscope (TEM) in detail. FIB analysis clearly shows there exist honey-combed cell structure with thin carbon walls in the dust particle and the dust particle grows from the graphite surface. TEM image also shows that the dust particle is made of amorphous carbon with crystallized grains with diameters of 10-50 nm.

40 CFR 1700.14 - Marine Pollution Control Device (MPCD) Performance Standards. [Reserved

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Marine Pollution Control Device (MPCD... UNIFORM NATIONAL DISCHARGE STANDARDS FOR VESSELS OF THE ARMED FORCES Marine Pollution Control Device (MPCD) Performance Standards § 1700.14 Marine Pollution Control Device (MPCD) Performance Standards. [Reserved] ...

Reactor power control device

International Nuclear Information System (INIS)

Imaruoka, Hiromitsu.

1994-01-01

A high pressure water injection recycling system comprising injection pipelines of a high pressure water injection system and a flow rate control means in communication with a pool of a pressure control chamber is disposed to a feedwater system of a BWR type reactor. In addition, the flow rate control means is controlled by a power control device comprising a scram impossible transient event judging section, a required injection flow rate calculation section for high pressure water injection system and a control signal calculation section. Feed water flow rate to be supplied to the reactor is controlled upon occurrence of a scram impossible transient event of the reactor. The scram impossible transient event is judged based on reactor output signals and scram operation demand signals and injection flow rate is calculated based on a predetermined reactor water level, and condensate storage tank water or pressure control chamber pool water is injected to the reactor. With such procedures, water level can be ensured and power can be suppressed. Further, condensate storage tank water of low enthalpy is introduced to the pressure suppression chamber pool to directly control elevation of water temperature and ensure integrity of the pressure vessel and the reactor container. (N.H.)

Piezo Voltage Controlled Planar Hall Effect Devices.

Science.gov (United States)

Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

2016-06-22

The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

Control of house-dust mites with home disinfectants

NARCIS (Netherlands)

Schober, G.; Wetter, G.; Bischoff, E.; Bronswijk, van J.E.M.H.; Kniest, F.M.

1987-01-01

Chemical disinfectants and biocidal preparations used in households were tested in the laboratory for their ability to kill the house-dust miteDermatophagoides farinae. Batches of ten specimens were soaked in aqueous solutions or suspensions containing 0.0, 0.1, 0.3, 1.0, 3.0 and 10.0% (by volume)

Fast-acting nuclear reactor control device

International Nuclear Information System (INIS)

Kotlyar, O.M.; West, P.B.

1993-01-01

A fast-acting nuclear reactor control device is described for controlling a safety control rod within the core of a nuclear reactor, the reactor controlled by a reactor control system, the device comprising: a safety control rod drive shaft and an electromagnetic clutch co-axial with the drive shaft operatively connected to the safety control rod for driving and positioning the safety control rod within or without the reactor core during reactor operation, the safety rod being oriented in a substantially vertical position to allow the rod to fall into the reactor core under the influence of gravity during shutdown of the reactor; the safety control rod drive shaft further operatively connected to a hydraulic pump such that operation of the drive shaft simultaneously drives and positions the safety control rod and operates the hydraulic pump such that a hydraulic fluid is forced into an accumulator, filling the accumulator with oil for the storage and supply of primary potential energy for safety control rod insertion such that the release of potential energy in the accumulator causes hydraulic fluid to flow through the hydraulic pump, converting the hydraulic pump to a hydraulic motor having speed and power capable of full length insertion and high speed driving of the safety control rod into the reactor core; a solenoid valve interposed between the hydraulic pump and the accumulator, said solenoid valve being a normally open valve, actuated to close when the safety control rod is out of the reactor during reactor operation; and further wherein said solenoid opens in response to a signal from the reactor control system calling for shutdown of the reactor and rapid insertion of the safety control rod into the reactor core, such that the opening of the solenoid releases the potential energy in the accumulator to place the safety control rod in a safe shutdown position

Fusion oriented plasma research in Bangladesh: theoretical study on low-frequency dust modes and edge plasma control experiment in tandem mirror

International Nuclear Information System (INIS)

Khairul Islam, Md.; Salimullah, Mohammed; Yatsu, Kiyoshi; Nakashima, Yousuke; Ishimoto, Yuki

2003-01-01

A collaboration with a Japanese institute in the field of plasma-wall interaction and dusty plasma has been formed in order to understand the physical properties of edge plasma. Results of the theoretical study on dusty plasma and the experimental study on GAMMA10 plasma are presented in this paper. Part A deals with the results obtained from the theoretical investigation of the properties and excitation of low-frequency electrostatic dust modes, e.g. the dust-acoustic (DA) and dust-lower-hybrid (DLH) waves, using the fluid models. In this study, dust grain charge is considered as a dynamic variable in streaming magnetized dusty plasmas with a background of neutral atoms. Dust charge fluctuation, collisional and streaming effects on DA and DLH modes are discussed. Part B deals with the results of the plasma control experiment in a non-axisymmetric magnetic field region of the anchor cell of GAMMA10. The observations, which indicate the comparatively low-temperature plasma formation in the anchor cell, are explained from the viewpoint of enhanced outgassing from the wall due to the interaction of the drifted-out ions. The drifting of ions is thought to be due to the effect of a local non-axisymmetric magnetic field. Experimental results on the control of the wall-plasma interaction by covering the flux tube of a non-axisymmetric magnetic field region by conducting plates are given. Possible influences of the asymmetric magnetic field and conducting plates on the GAMMA10 plasma parameters are discussed. (author)

Semi-active control of helicopter vibration using controllable stiffness and damping devices

Science.gov (United States)

Anusonti-Inthra, Phuriwat

Semi-active concepts for helicopter vibration reduction are developed and evaluated in this dissertation. Semi-active devices, controllable stiffness devices or controllable orifice dampers, are introduced; (i) in the blade root region (rotor-based concept) and (ii) between the rotor and the fuselage as semi-active isolators (in the non-rotating frame). Corresponding semi-active controllers for helicopter vibration reduction are also developed. The effectiveness of the rotor-based semi-active vibration reduction concept (using stiffness and damping variation) is demonstrated for a 4-bladed hingeless rotor helicopter in moderate- to high-speed forward flight. A sensitivity study shows that the stiffness variation of root element can reduce hub vibrations when proper amplitude and phase are used. Furthermore, the optimal semi-active control scheme can determine the combination of stiffness variations that produce significant vibration reduction in all components of vibratory hub loads simultaneously. It is demonstrated that desired cyclic variations in properties of the blade root region can be practically achieved using discrete controllable stiffness devices and controllable dampers, especially in the flap and lag directions. These discrete controllable devices can produce 35--50% reduction in a composite vibration index representing all components of vibratory hub loads. No detrimental increases are observed in the lower harmonics of blade loads and blade response (which contribute to the dynamic stresses) and controllable device internal loads, when the optimal stiffness and damping variations are introduced. The effectiveness of optimal stiffness and damping variations in reducing hub vibration is retained over a range of cruise speeds and for variations in fundamental rotor properties. The effectiveness of the semi-active isolator is demonstrated for a simplified single degree of freedom system representing the semi-active isolation system. The rotor

Fluid control structures in microfluidic devices

Science.gov (United States)

Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

2017-05-09

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

Stabilizing device for control rod tip

International Nuclear Information System (INIS)

Verdone, G.F.

1982-01-01

A control rod has a spring device on its lower end for eliminating oscillatory contact of the rod against its adjacent guide tube wall. The base of the device is connected to the lower tip of the rod. A plurality of elongated extensions are cantilevered downward from the base. Each extension has a shoulder for contacting the guide tube, and the plurality of shoulders as a group has a transverse dimension that is preset to be larger than the inner diameter of the guide tube such that an interference fit is obtained when the control rod is inserted in the tube. The elongated extensions form an open-ended, substantially hollow member through which most of the liquid coolant flows, and the spaces between adjacent extensions allow the flow to bypass the shoulders without experiencing a significant pressure drop

Laboratory Investigation of Space and Planetary Dust Grains

Science.gov (United States)

Spann, James

2005-01-01

Dust in space is ubiquitous and impacts diverse observed phenomena in various ways. Understanding the dominant mechanisms that control dust grain properties and its impact on surrounding environments is basic to improving our understanding observed processes at work in space. There is a substantial body of work on the theory and modeling of dust in space and dusty plasmas. To substantiate and validate theory and models, laboratory investigations and space borne observations have been conducted. Laboratory investigations are largely confined to an assembly of dust grains immersed in a plasma environment. Frequently the behaviors of these complex dusty plasmas in the laboratory have raised more questions than verified theories. Space borne observations have helped us characterize planetary environments. The complex behavior of dust grains in space indicates the need to understand the microphysics of individual grains immersed in a plasma or space environment.

Control rod withdrawal monitoring device

International Nuclear Information System (INIS)

Ebisuya, Mitsuo.

1984-01-01

Purpose: To prevent the power ramp even if a plurality of control rods are subjected to withdrawal operation at a time, by reducing the reactivity applied to the reactor. Constitution: The control rod withdrawal monitoring device is adapted to monitor and control the withdrawal of the control rods depending on the reactor power and the monitoring region thereof is divided into a control rod group monitoring region a transition region and a control group monitoring not interfere region. In a case if the distance between a plurality of control rods for which the withdrawal positions are selected is less than a limiting value, the coordinate for the control rods, distance between the control rods and that the control rod distance is shorter are displayed on a display panel, and the withdrawal for the control rods are blocked. Accordingly, even if a plurality of control rods are subjected successively to the withdrawal operation contrary to the control rod withdrawal sequence upon high power operation of the reactor, the power ramp can be prevented. (Kawakami, Y.)

Control device for handling device of control rod drive

International Nuclear Information System (INIS)

Sasaki, Toshiya

1998-01-01

A predetermined aimed portion of control rod drives disposed in a pedestal is photographed, and image data and camera data including the position of the camera are outputted. Edge cut out processing image data are formed based on the outputted image data, and aimed image data and aimed camera data obtained when previously positioning the handling device precisely to a predetermined aimed position are stored. The aimed image data are taken out from the aimed image data file to prepare computer graphic image data, and there is disposed an image superposing processing portion for comparing images based on the computer graphic image data and images based on the image data for edge cut out processing, as well as comparing the aimed camera data and the camera data, and displaying each of them to an image display portion. (I.S.)

Bioaccessibility of Fipronil Sorbed to Soil and House Dust

Science.gov (United States)

Fipronil is a phenylpyrazole insecticide with uses ranging from soil treatment, to the control of household pests and ectoparasites on pets. Soils and house dusts readily sorb fipronil and when these soils and dusts are ingested, the fipronil may become bioaccessible for uptake ...

Dust confinement and dust acoustic waves in a magnetized plasma

Science.gov (United States)

Piel, A.

2005-10-01

Systematic laboratory experiments on dust acoustic waves require the confinement of dust particles. Here we report on new experiments in a magnetized plasma region in front of an additional positively biased disk electrode in a background plasma which is generated in argon at 27MHz between a disk and grid electrode. The plasma diffuses through the grid along the magnetic field. The three-dimensional dust distribution is measured with a horizontal sheet of laser light and a CCD camera, which are mounted on a vertical translation stage. Depending on magnetic field and discharge current, cigar or donut-shaped dust clouds are generated, which tend to rotate about the magnetic field direction. Measurements with emissive probes show that the axial confinement of dust particles with diameters between 0.7-2 μm is achieved by a balance of ion-drag force and electric field force. Dust levitation and radial confinement is due to a strong radial electric field. Dust acoustic waves are destabilized by the ion flow or can be stimulated by a periodic bias on the disk electrode. The observed wave dispersion is compared with fluid and kinetic models of the dust acoustic wave.

Controlled human exposure to indoor air, dust, and ozone; XDOZ

DEFF Research Database (Denmark)

Elholm, Grethe; Bønløkke, Jakob; Schlünssen, Vivi

2017-01-01

. All participants were subjected to four different exposure scenarios in the climate chamber.Exp. 1: Dust (250 – 300 µg/m3)Exp. 2: Ozone (100 ppb)Exp. 3: Dust (250 – 300 µg/m3) + ozone (100 ppb)Exp. 4: Filtered air (<20µg/m3)The exposure time was 5½ hours for each session.The health effects were...... evaluated at baseline and specific follow-up times in relation to selected respiratory and cardiovascular outcomes, such as; nasal volume, exhaled nitric oxide (FENO), spirometry (FEV1 and FVC), exhaled breath condensate (EBC), nasal lavage, blood samples, EndoPat. Questionnaires were used for assessment...

Allergies, asthma, and dust

Science.gov (United States)

Reactive airway disease - dust; Bronchial asthma - dust; Triggers - dust ... Things that make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are ...

Prototyping of concurrent control systems implemented in FPGA devices

CERN Document Server

Wiśniewski, Remigiusz

2017-01-01

This book focuses on prototyping aspects of concurrent control systems and their further implementation and partial reconfiguration in programmable devices. Further, it lays out a full prototyping flow for concurrent control systems. Based on a given primary specification, a system is described with an interpreted Petri net, which naturally reflects the concurrent and sequential relationships of the design. The book shows that, apart from the traditional option of static configuration of the entire system, the latest programmable devices (especially FPGAs) offer far more sophistication. Partial reconfiguration allows selected parts of the system to be replaced without having to reprogram the entire structure of the device. Approaches to dynamic and static partial reconfiguration of concurrent control systems are presented and described in detail.< The theoretical work is illustrated by examples drawn from various applications, with a milling machine and a traffic-light controller highlighted as representat...

Norms concerning the programmable automatic control devices

International Nuclear Information System (INIS)

Fourmentraux, G.

1995-01-01

This presentation is a report of the studies carried out by the Work Group on Functioning Safety of Programmable Automatic Control Devices and by the Group for Prevention Studies (GEP) from the CEA. The objective of these groups is to evaluate the methods which could be used to estimate the functioning safety of control and instrumentation systems involved in the Important Elements for Safety (EIS) of the Basic Nuclear Installations (INB) of the CEA, and also to carry out a qualification of automatic control devices. Norms, protocols and tools for the evaluation are presented. The problem comprises two aspects: the evaluation of fault avoidance techniques and the evaluation of fault control techniques used during the conceiving. For the fault avoidance techniques, the quality assurance organization, the environment tests, and the software quality plans are considered. For the fault control techniques, the different available tools and fault injection models are analysed. The results of an analysis carried out with the DEF.I tool from the National Institute for Research and Safety (INRS) are reported. (J.S.). 23 refs

Optimising a fall out dust monitoring sampling programme at a ...

African Journals Online (AJOL)

GREG

Key words: Fall out dust monitoring, cement plant, optimising, air pollution sampling, fall out dust sampler locations. .... applied for those areas where controls are in place. Sampling ..... mass balance in the total cement manufacturing process.

Carbohydrate and protein contents of grain dusts in relation to dust morphology.

Science.gov (United States)

Dashek, W V; Olenchock, S A; Mayfield, J E; Wirtz, G H; Wolz, D E; Young, C A

1986-01-01

Grain dusts contain a variety of materials which are potentially hazardous to the health of workers in the grain industry. Because the characterization of grain dusts is incomplete, we are defining the botanical, chemical, and microbial contents of several grain dusts collected from grain elevators in the Duluth-Superior regions of the U.S. Here, we report certain of the carbohydrate and protein contents of dusts in relation to dust morphology. Examination of the gross morphologies of the dusts revealed that, except for corn, each dust contained either husk or pericarp (seed coat in the case of flax) fragments in addition to respirable particles. When viewed with the light microscope, the fragments appeared as elongated, pointed structures. The possibility that certain of the fragments within corn, settled, and spring wheat were derived from cell walls was suggested by the detection of pentoses following colorimetric assay of neutralized 2 N trifluoroacetic acid hydrolyzates of these dusts. The presence of pentoses together with the occurrence of proteins within water washings of grain dusts suggests that glycoproteins may be present within the dusts. With scanning electron microscopy, each dust was found to consist of a distinct assortment of particles in addition to respirable particles. Small husk fragments and "trichome-like" objects were common to all but corn dust. Images FIGURE 4. FIGURE 5. PMID:3709476

Observation of Dust in DIII-D Divertor and SOL by Visible Imaging

International Nuclear Information System (INIS)

Rudakov, D L; West, W P; Groth, M; Yu, J H; Wong, C C; Boedo, J A; Brooks, N H; Evans, T E; Fenstermacher, M E; Hollmann, E M; Hyatt, A W; Lasnier, C J; McLean, A G; Moyer, R A; Pigarov, A; Smirnov, R; Solomon, W M; Watkins, J G

2007-01-01

Dust is commonly found in fusion devices. Though generally of no concern in the present day machines, dust may pose serious safety and operational concerns for ITER. Micron-size dust usually dominates the samples collected from tokamaks. During a plasma discharge micron-size dust particles can become highly mobile and travel over distances of a few meters. Once inside the plasma, dust particles heat up to over 3000 K and emit thermal radiation that can be detected by visible imaging techniques. Observations of naturally occurring and artificially introduced dusts have been performed in DIII-D divertor and scrape-off layer (SOL) using standard frame rate CMOS cameras, a gated-intensified CID camera, and a fast-framing CMOS camera. In the first 2-3 plasma discharges after a vent with personnel entry inside the vacuum vessel ('dirty vent') dust levels were quite high with thousands of particles observed in each discharge. Individual particles moving at velocities of up to a few hundred m/s and breakup of larger particles into pieces were observed. After about 15 discharges dust was virtually gone during the stationary portion of a discharge, and appeared at much reduced levels during the plasma initiation and termination phases. After a few days of plasma operations (about 70 discharges) dust levels were further reduced to just a few observed events per discharge except in discharges with current disruptions that produced significant amounts of dust. An injection of a few milligram of micron-size (6 micron median diameter) carbon dust into a high-power lower single-null ELMing H-mode discharge with strike points swept across the lower divertor floor was performed. A significant increase of the core carbon radiation was observed for about 250 ms after the injection, as the total radiated power increased twofold. Dust particles from the injection were observed by the fast framing camera in the outboard SOL near the midplane. The amount of dust observed by the fast

Dust Devil Tracks

Science.gov (United States)

2002-01-01

(Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

Plasma Equilibrium Control in Nuclear Fusion Devices 2. Plasma Control in Magnetic Confinement Devices 2.1 Plasma Control in Tokamaks

Science.gov (United States)

Fukuda, Takeshi

The plasma control technique for use in large tokamak devices has made great developmental strides in the last decade, concomitantly with progress in the understanding of tokamak physics and in part facilitated by the substantial advancement in the computing environment. Equilibrium control procedures have thereby been established, and it has been pervasively recognized in recent years that the real-time feedback control of physical quantities is indispensable for the improvement and sustainment of plasma performance in a quasi-steady-state. Further development is presently undertaken to realize the “advanced plasma control” concept, where integrated fusion performance is achieved by the simultaneous feedback control of multiple physical quantities, combined with equilibrium control.

Experience with dust suppression in mining a thick, dirty seam

Energy Technology Data Exchange (ETDEWEB)

Siepmann, D; Kohlhauer, H

1975-11-20

Dust suppression measures used when mining a thick, dirty seam are described. Dust sprays inside and outside the shearer drum helped to reduce coarse dust, but the resulting increase in moisture content of the coal limits the extent to which this method can be used. The shields were also fitted with sprays. Because of the dirt in the seam, continuous, remotely controlled deep infusion was used. This reduced the dust concentration from more than 10 mg/m/sup 3/ to between 3.9 and 6.6 mg/m/sup 3/.

Digital Control of External Devices through the Parallel Port of a ...

African Journals Online (AJOL)

Digital Control of External Devices through the Parallel Port of a Computer Using Visual Basic. ... Nigerian Journal of Technology ... Keywords: device controller, digital switching, digital interfacing, visual basic, computer parallel port ...

Bidirectional Telemetry Controller for Neuroprosthetic Devices

Science.gov (United States)

Sharma, Vishnu; McCreery, Douglas B.; Han, Martin; Pikov, Victor

2010-01-01

We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s, allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes ∼420 mW and operates without recharge for 8 h. It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 μs after the end of the stimulus pulse applied in the cochlear nucleus. PMID:19933010

Bidirectional telemetry controller for neuroprosthetic devices.

Science.gov (United States)

Sharma, Vishnu; McCreery, Douglas B; Han, Martin; Pikov, Victor

2010-02-01

We present versatile multifunctional programmable controller with bidirectional data telemetry, implemented using existing commercial microchips and standard Bluetooth protocol, which adds convenience, reliability, and ease-of-use to neuroprosthetic devices. Controller, weighing 190 g, is placed on animal's back and provides bidirectional sustained telemetry rate of 500 kb/s , allowing real-time control of stimulation parameters and viewing of acquired data. In continuously-active state, controller consumes approximately 420 mW and operates without recharge for 8 h . It features independent 16-channel current-controlled stimulation, allowing current steering; customizable stimulus current waveforms; recording of stimulus voltage waveforms and evoked neuronal responses with stimulus artifact blanking circuitry. Flexibility, scalability, cost-efficiency, and a user-friendly computer interface of this device allow use in animal testing for variety of neuroprosthetic applications. Initial testing of the controller has been done in a feline model of brainstem auditory prosthesis. In this model, the electrical stimulation is applied to the array of microelectrodes implanted in the ventral cochlear nucleus, while the evoked neuronal activity was recorded with the electrode implanted in the contralateral inferior colliculus. Stimulus voltage waveforms to monitor the access impedance of the electrodes were acquired at the rate of 312 kilosamples/s. Evoked neuronal activity in the inferior colliculus was recorded after the blanking (transient silencing) of the recording amplifier during the stimulus pulse, allowing the detection of neuronal responses within 100 mus after the end of the stimulus pulse applied in the cochlear nucleus.

Experimental and simulated control of lift using trailing edge devices

Science.gov (United States)

Cooperman, A.; Blaylock, M.; van Dam, C. P.

2014-12-01

Two active aerodynamic load control (AALC) devices coupled with a control algorithm are shown to decrease the change in lift force experienced by an airfoil during a change in freestream velocity. Microtabs are small (1% chord) surfaces deployed perpendicular to an airfoil, while microjets are pneumatic jets with flow perpendicular to the surface of the airfoil near the trailing edge. Both devices are capable of producing a rapid change in an airfoil's lift coefficient. A control algorithm for microtabs has been tested in a wind tunnel using a modified S819 airfoil, and a microjet control algorithm has been simulated for a NACA 0012 airfoil using OVERFLOW. In both cases, the AALC devices have shown the ability to mitigate the changes in lift during a gust.

Control-rod scram device

International Nuclear Information System (INIS)

Matsui, Yoshiro; Saito, Koji.

1986-01-01

Purpose: To eliminate the requirement for the nitrogen gas system in a scram device and enable safety and reliable shutdown of a water-cooled reactor power plant. Constitution: A piston and a spring are contained within a hydraulic vessel, and the piston is driven by the energy stored in the spring so as to supply hydraulic water to control mechanisms. During usual reactor operation, a scram valve is closed and a high water pressure of about 130 kg/cm 2 is applied to the water filled in the vessel through a check valve. Upon occurrence of abnormal conditions and generation of scram signals, the scram valve is opened to supply the water filled in the vessel through the scram valve to the control rod drive mechanisms. When the water pressure in the vessel is decreased, since the piston is urged upwardly by the energy stored in the spring, the water filled in the vessel is intermitently supplied to the control rod drive mechanisms. Thus, control rods can be inserted into the nuclear reactor to shutdown the same. (Horiuchi, T.)

Scattering and extinction of ion beams in a dusty plasma device

International Nuclear Information System (INIS)

Nakamura, Y.

2001-01-01

Collisions of ions with charged dust grains are important for the propagation of low frequency waves such as dust acoustic waves and dust ion-acoustic waves. The collision cross-sectional area of charged dust grains depends on the velocity of an ion beam. The collision cross-sectional area of charged dust grains with beam ions is measured. It is compared with the geometrical cross-sectional area of the grain. The experiment is performed in a dusty double-plasma device with glass beads of 8.9 μm in average diameter. The ion beam current and energy are measured with a directional retarding potential analyzer. It is observed that, when dust density inside the system is increased, the beam current ratio is reduced. From the reduction of the ion beam current, the effective cross-sectional area of the dust particle is estimated as a function of the beam energy

Lead in Chinese villager house dust: Geographical variation and influencing factors

International Nuclear Information System (INIS)

Bi, Xiangyang; Liu, Jinling; Han, Zhixuan; Yang, Wenlin

2015-01-01

House dust has been recognized as an important contributor to Pb exposure of children. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The influences of outdoor soil Pb concentrations, dates of construction, house decoration materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with a median concentration of 42 mg/kg. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decoration materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. Principal component analysis (PCA) confirmed that elemental compositions of the house dust were controlled by both anthropogenic and geogenic sources. Using scanning electron microscopy (SEM), the Pb bearing particles in the house dust were also studied. - Highlights: • Geographical variation in house dust Pb concentrations were observed. • Dust Pb concentrations were not associated with house age and decoration materials. • Soil, coal combustion, and site specific pollution were potential Pb sources. • Pb bearing particles were identified by SEM-EDX. - The variations of Pb in Chinese villager house dust were controlled by outdoor soil, coal combustion, and site specific pollution sources.

Practical design control implementation for medical devices

CERN Document Server

Justiniano, Jose

2003-01-01

Bringing together the concepts of design control and reliability engineering, this book is a must for medical device manufacturers. It helps them meet the challenge of designing and developing products that meet or exceed customer expectations and also meet regulatory requirements. Part One covers motivation for design control and validation, design control requirements, process validation and design transfer, quality system for design control, and measuring design control program effectiveness. Part Two discusses risk analysis and FMEA, designing-in reliability, reliability and design verific

Worker exposure to silica dust in South African non-mining industries in Gauteng: An exploratory study

CSIR Research Space (South Africa)

Khoza, NN

2012-06-01

Full Text Available %, and sandblasting 2.4%. The overall maximum and minimum exposures were 5.772 and 0.009 mg/m?, respectively. Conclusion: Workers are potentially at high risk of contracting silicosis and other diseases associated with respirable silica dust. Dust control... and monitoring were inadequate in the industries visited. It is recommended that an in-depth study be conducted and that airborne dust-control programmes be implemented. Key words: non-mining industries, silica dust, respirable crystalline silica dust...

Kuiper Belt Dust Grains as a Source of Interplanetary Dust Particles

Science.gov (United States)

Liou, Jer-Chyi; Zook, Herbert A.; Dermott, Stanley F.

1996-01-01

The recent discovery of the so-called Kuiper belt objects has prompted the idea that these objects produce dust grains that may contribute significantly to the interplanetary dust population. In this paper, the orbital evolution of dust grains, of diameters 1 to 9 microns, that originate in the region of the Kuiper belt is studied by means of direct numerical integration. Gravitational forces of the Sun and planets, solar radiation pressure, as well as Poynting-Robertson drag and solar wind drag are included. The interactions between charged dust grains and solar magnetic field are not considered in the model. Because of the effects of drag forces, small dust grains will spiral toward the Sun once they are released from their large parent bodies. This motion leads dust grains to pass by planets as well as encounter numerous mean motion resonances associated with planets. Our results show that about 80% of the Kuiper belt grains are ejected from the Solar System by the giant planets, while the remaining 20% of the grains evolve all the way to the Sun. Surprisingly, the latter dust grains have small orbital eccentricities and inclinations when they cross the orbit of the Earth. This makes them behave more like asteroidal than cometary-type dust particles. This also enhances their chances of being captured by the Earth and makes them a possible source of the collected interplanetary dust particles; in particular, they represent a possible source that brings primitive/organic materials from the outer Solar System to the Earth. When collisions with interstellar dust grains are considered, however, Kuiper belt dust grains around 9 microns appear likely to be collisionally shattered before they can evolve toward the inner part of the Solar System. The collision destruction can be applied to Kuiper belt grains up to about 50 microns. Therefore, Kuiper belt dust grains within this range may not be a significant part of the interplanetary dust complex in the inner Solar

Respirable dust and respirable silica exposure in Ontario gold mines.

Science.gov (United States)

Verma, Dave K; Rajhans, Gyan S; Malik, Om P; des Tombe, Karen

2014-01-01

A comprehensive survey of respirable dust and respirable silica in Ontario gold mines was conducted by the Ontario Ministry of Labor during 1978-1979. The aim was to assess the feasibility of introducing gravimetric sampling to replace the assessment method which used konimeters, a device which gave results in terms of number of particles per cubic centimeter (ppcc) of air. The study involved both laboratory and field assessments. The field assessment involved measurement of airborne respirable dust and respirable silica at all eight operating gold mines of the time. This article describes the details of the field assessment. A total of 288 long-term (7-8 hr) personal respirable dust air samples were collected from seven occupational categories in eight gold mines. The respirable silica (α-quartz) was determined by x-ray diffraction method. The results show that during 1978-1979, the industry wide mean respirable dust was about 1 mg/m(3), and the mean respirable silica was 0.08 mg/m(3.)The mean% silica in respirable dust was 7.5%. The data set would be useful in future epidemiological and health studies, as well as in assessment of workers' compensation claims for occupational diseases such as silicosis, chronic obstructive pulmonary disease (COPD), and autoimmune diseases such as renal disease and rheumatoid arthritis.

Hygienic evaluation of new technology for control of methane and dust in coal mines

Energy Technology Data Exchange (ETDEWEB)

Gadzhiev, G P; Deynega, V G; Sukhanov, V V; Levshina, I M; Yarym, N T; Petrenko, G A

1977-07-01

Exploitation of available new technology for mining is hindered by the dangers of gas evolution, and the need for maintenance of hygienic standards. The Moscow Mining Institute has developed, and proposed for industrial introduction, a new process for control of methane and dust in mine shafts; the method will help to raise significantly the productivity of excavating machines in high gas factor shafts. The process to combat methane and dust consists essentially in drilling boreholes from the side of the gallery, or from the outer surface, into the coal-bearing stratum. These boreholes are injected with a 24% solution of urea-formaldehyde resin (binder M/sub 2/), with 1% solution of ammonium chloride hardener. After several months this plastic is removed. The new technology involves the escape of toxic substances into the air, hence the need for hygienic testing. Additional study must estimate the danger of accidents, e.g., shaft fires, toxicity of combustion products of coal or binder. Study is also needed on pathologies which might occur to miners engaged in removal of the plastic with the new technology.

Migrated Essure permanent birth control device: sonographic findings.

Science.gov (United States)

Khati, Nadia Juliet; Gorodenker, Joseph; Brindle, Kathleen Ann

2014-05-01

We report a case of a migrated Essure permanent birth control device. The correct diagnosis was made on conventional two-dimensional and three-dimensional pelvic sonography 7 years after placement of the device when the patient presented with persistent right-sided pain. The 3-month post placement hysterosalpingogram had shown an appropriately occluded right fallopian tube but had overlooked the abnormal position of the right Essure device, which was too proximal and extending slightly in the uterine cavity. Copyright © 2013 Wiley Periodicals, Inc.

Comparison of conventional and bio-treated methods as dust suppressants.

Science.gov (United States)

Naeimi, Maryam; Chu, Jian

2017-10-01

Dust is an environmental, geotechnical, health, and economical hazard. Fugitive dust emanating along transportation systems such as roads, railways, and airports especially can have significant impacts on health, safety, material loss, cost of maintenance, and interfere with the facilities. Quantitative studies on the effectiveness of the proper dust palliatives and their environmental impact have been studied with a number of biological and chemical methods. The objective of this study was to establish a method for using the microbial Induced calcium carbonate precipitation (MICP) approach to reduce the percent of mass loss against erosive force of wind regarding to the concentration and characteristics of aggregate used, climate, and traffic amounts. The results of this study showed that the required precipitation for dust control of sand by 70% is less than 15 g CaCO 3 /m 2 between sand grains in bio-treated sand. The wind tunnel test results of this study also indicate that the effectiveness of the bio-treatment method for dust control depends on many variables, such as the percent of precipitated calcium carbonate and tensile strength.

Product screening for sources of halogenated flame retardants in Canadian house and office dust

Energy Technology Data Exchange (ETDEWEB)

Abbasi, Golnoush [Department of Geography, University of Toronto, 100 St. George St., Toronto M5S 3G3 (Canada); Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4 (Canada); Goosey, Emma [Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1 (Canada); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4 (Canada)

2016-03-01

Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing. - Highlights: • Concentrations of flame retardants in dust correlated with product surface wipes • Most abundant FRs in electronics were PBDEs, TDCPP, DBDPE, EH-TBB and BEHTBP. • Descending order of FRs in CRTs, TVs, PCs, A-V devices, and small household appliances • Product wipe testing, but not XRF, useful for non

Product screening for sources of halogenated flame retardants in Canadian house and office dust

International Nuclear Information System (INIS)

Abbasi, Golnoush; Saini, Amandeep; Goosey, Emma; Diamond, Miriam L.

2016-01-01

Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing. - Highlights: • Concentrations of flame retardants in dust correlated with product surface wipes • Most abundant FRs in electronics were PBDEs, TDCPP, DBDPE, EH-TBB and BEHTBP. • Descending order of FRs in CRTs, TVs, PCs, A-V devices, and small household appliances • Product wipe testing, but not XRF, useful for non

Modeling Respiratory Toxicity of Authentic Lunar Dust

Science.gov (United States)

Santana, Patricia A.; James, John T.; Lam, Chiu-Wing

2010-01-01

The lunar expeditions of the Apollo operations from the 60 s and early 70 s have generated awareness about lunar dust exposures and their implication towards future lunar explorations. Critical analyses on the reports from the Apollo crew members suggest that lunar dust is a mild respiratory and ocular irritant. Currently, NASA s space toxicology group is functioning with the Lunar Airborne Dust Toxicity Assessment Group (LADTAG) and the National Institute for Occupational Safety and Health (NIOSH) to investigate and examine toxic effects to the respiratory system of rats in order to establish permissible exposure levels (PELs) for human exposure to lunar dust. In collaboration with the space toxicology group, LADTAG and NIOSH the goal of the present research is to analyze dose-response curves from rat exposures seven and twenty-eight days after intrapharyngeal instillations, and model the response using BenchMark Dose Software (BMDS) from the Environmental Protection Agency (EPA). Via this analysis, the relative toxicities of three types of Apollo 14 lunar dust samples and two control dust samples, titanium dioxide (TiO2) and quartz will be determined. This will be executed for several toxicity endpoints such as cell counts and biochemical markers in bronchoaveolar lavage fluid (BALF) harvested from the rats.

Whither Cometary Dust?

Science.gov (United States)

Lisse, Carey M.

2010-10-01

In this paper I will discuss recent findings that have important implications for our understanding of the formation and evolution of primitive solar system dust, including: - Nesvorny et al. (2010), following up on their dynamical analyses of the zodiacal dust bands as sourced by the breakup of the Karin (5Mya) and Veritas (8Mya) asteroid families, argue that over 90% of the interplanetary dust cloud at 1 AU comes from JFC comets with near-circularized, low inclination orbits. This implies that the noted IPD collections of anhydrous and hydrous dust particles are likely to be from Oort cloud and JFC comets, respectively, not from asteroids and comets as thought in the past. Hydrous dust particles from comets like 85P/Wild2 and 9P/Tempel 1 would be consistent with results from the STARDUST and Deep Impact experiments. - Estimates of the dust particle size distributions (PSDs) in the comae of 85P/Wild2 (Green et al. 2004, 2007) and 73P/SW-3 (Sitko et al. 2010, Vaubaillon & Reach 2010) and in the trails of comets (Reach et al. 2007) have broken power law structure, with a plateau enhancement of particles of 1 mm - 1 cm in size. This size is also the size of most chondritic inclusions, and the predicted size range of the "aggregational barrier", where collisions between dust particles become destructive. - Studies of the albedo and polarization properties of cometary dust (Kolokolova et al. 2007) suggest there are 2 major groupings, one with low scattering capability and one with high. While these families could possibly have been explained by systematics in the PSDs of the emitted dust, independent work by Lisse et al. (2008) on the mineralogy of a number of highly dusty comets has shown evidence for one family of comets with highly crystalline dust and another with highly amorphous dust.

Integrative Analysis of Desert Dust Size and Abundance Suggests Less Dust Climate Cooling

Science.gov (United States)

Kok, Jasper F.; Ridley, David A.; Zhou, Qing; Miller, Ron L.; Zhao, Chun; Heald, Colette L.; Ward, Daniel S.; Albani, Samuel; Haustein, Karsten

2017-01-01

Desert dust aerosols affect Earths global energy balance through interactions with radiation, clouds, and ecosystems. But the magnitudes of these effects are so uncertain that it remains unclear whether atmospheric dust has a net warming or cooling effect on global climate. Consequently, it is still uncertain whether large changes in atmospheric dust loading over the past century have slowed or accelerated anthropogenic climate change, and the climate impact of possible future alterations in dust loading is similarly disputed. Here we use an integrative analysis of dust aerosol sizes and abundance to constrain the climatic impact of dust through direct interactions with radiation. Using a combination of observational, experimental, and model data, we find that atmospheric dust is substantially coarser than represented in current climate models. Since coarse dust warms global climate, the dust direct radiative effect (DRE) is likely less cooling than the 0.4 W m superscript 2 estimated by models in a current ensemble. We constrain the dust DRE to -0.20 (-0.48 to +0.20) W m superscript 2, which suggests that the dust DRE produces only about half the cooling that current models estimate, and raises the possibility that dust DRE is actually net warming the planet.

Signaling Pathways Involved in Lunar Dust Induced Cytotoxicity

Science.gov (United States)

Zhang, Ye; Lam, Chiu-Wing; Scully, Robert R.; Williams, Kyle; Zalesak, Selina; Wu, Honglu; James, John T.

2014-01-01

The Moon's surface is covered by a layer of fine, reactive dust. Lunar dust contain about 1-2% of very fine dust (pathways involved in lunar dust-induced toxicity. F344 rats were exposed for 4 weeks (6h/d; 5d/wk) in nose-only inhalation chambers to concentrations of 0 (control air), 2.1, 6.1, 21, and 61 mg/m(exp 3) of lunar dust. Five rats per group were euthanized 1 day, 1 week, 1 month, and 3 months after the last inhalation exposure. The total RNAs were isolated from the blood or lung tissue after being lavaged, using the Qigen RNeasy kit. The Rat Fibrosis RT2 Profile PCR Array was used to profile the expression of 84 genes relevant to fibrosis. The genes with significant expression changes are identified and the gene expression data were further analyzed using IPA pathway analysis tool to determine the signaling pathways with significant changes.

Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 m. Particle concentrations not exceeding 3.5 106 particles/m3 (100 000/ft 3) are covered for all particles equal to and larger than the minimum size measured. 1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size. Note 1The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling...

Experimental and simulated control of lift using trailing edge devices

International Nuclear Information System (INIS)

Cooperman, A; Blaylock, M; Van Dam, C P

2014-01-01

Two active aerodynamic load control (AALC) devices coupled with a control algorithm are shown to decrease the change in lift force experienced by an airfoil during a change in freestream velocity. Microtabs are small (1% chord) surfaces deployed perpendicular to an airfoil, while microjets are pneumatic jets with flow perpendicular to the surface of the airfoil near the trailing edge. Both devices are capable of producing a rapid change in an airfoil's lift coefficient. A control algorithm for microtabs has been tested in a wind tunnel using a modified S819 airfoil, and a microjet control algorithm has been simulated for a NACA 0012 airfoil using OVERFLOW. In both cases, the AALC devices have shown the ability to mitigate the changes in lift during a gust

Oxydative stress in rats caused by coal dust plus cigarette smoke

Directory of Open Access Journals (Sweden)

Nia Kania

2016-02-01

Full Text Available Coal dust and cigarette smoke are pollutants found in coal mines that are capable of inducing oxidative stress, the effects of which on blood malondialdehyde (MDA level and serum superoxide dismutase (SOD level are still unknown. The purpose of the present study was to evaluate the effect of coal dust and cigarette smoke on levels of MDA and SOD in rats. An experimental study was done on Wistar male rats divided into the following groups: control (C, coal dust exposure (14 days (CDE, cigarette smoke exposure (14 days (CSE, coal dust exposure (7 days followed by cigarette smoke exposure (7 days (CDE+CSE, cigarette smoke exposure (7 days followed by coal dust exposure (7 days (CSE+CDE. All exposures increased MDA levels and decreased SOD activity significantly between groups (p=0.000. All exposure groups had significantly increased blood MDA levels, compared to the control group, although there was no difference between CSE + CDE and CDE + CSE. For SOD levels, all exposure groups had significantly decreased the SOD levels compared to control. But there were no significant differences between CSE vs CDE and CDE + CSE vs CSE + CDE. We conclude that exposure to cigarette smoke significantly increases blood MDA level and decreases serum SOD activity, which was not found in exposure to coal dust. Combined exposures also increase blood MDA level and decrease serum SOD activity significantly.

Oxydative stress in rats caused by coal dust plus cigarette smoke

Directory of Open Access Journals (Sweden)

Nia Kania

2011-08-01

Full Text Available Coal dust and cigarette smoke are pollutants found in coal mines that are capable of inducing oxidative stress, the effects of which on blood malondialdehyde (MDA level and serum superoxide dismutase (SOD level are still unknown. The purpose of the present study was to evaluate the effect of coal dust and cigarette smoke on levels of MDA and SOD in rats. An experimental study was done on Wistar male rats divided into the following groups: control (C, coal dust exposure (14 days (CDE, cigarette smoke exposure (14 days (CSE, coal dust exposure (7 days followed by cigarette smoke exposure (7 days (CDE+CSE, cigarette smoke exposure (7 days followed by coal dust exposure (7 days (CSE+CDE. All exposures increased MDA levels and decreased SOD activity significantly between groups (p=0.000. All exposure groups had significantly increased blood MDA levels, compared to the control group, although there was no difference between CSE + CDE and CDE + CSE. For SOD levels, all exposure groups had significantly decreased the SOD levels compared to control. But there were no significant differences between CSE vs CDE and CDE + CSE vs CSE + CDE. We conclude that exposure to cigarette smoke significantly increases blood MDA level and decreases serum SOD activity, which was not found in exposure to coal dust. Combined exposures also increase blood MDA level and decrease serum SOD activity significantly.

DUST PROPERTIES OF LOCAL DUST-OBSCURED GALAXIES WITH THE SUBMILLIMETER ARRAY

International Nuclear Information System (INIS)

Hwang, Ho Seong; Andrews, Sean M.; Geller, Margaret J.

2013-01-01

We report Submillimeter Array observations of the 880 μm dust continuum emission for four dust-obscured galaxies (DOGs) in the local universe. Two DOGs are clearly detected with S ν (880 μm) =10-13 mJy and S/N > 5, but the other two are not detected with 3σ upper limits of S ν (880 μm) =5-9 mJy. Including an additional two local DOGs with submillimeter data from the literature, we determine the dust masses and temperatures for six local DOGs. The infrared luminosities and dust masses for these DOGs are in the ranges of 1.2-4.9 × 10 11 (L ☉ ) and 4-14 × 10 7 (M ☉ ), respectively. The dust temperatures derived from a two-component modified blackbody function are 23-26 K and 60-124 K for the cold and warm dust components, respectively. Comparison of local DOGs with other infrared luminous galaxies with submillimeter detections shows that the dust temperatures and masses do not differ significantly among these objects. Thus, as argued previously, local DOGs are not a distinctive population among dusty galaxies, but simply represent the high-end tail of the dust obscuration distribution

Dust Destruction in the ISM: A Re-Evaluation of Dust Lifetimes

Science.gov (United States)

Jones, A. P.; Nuth, J. A., III

2011-01-01

There is a long-standing conundrum in interstellar dust studies relating to the discrepancy between the time-scales for dust formation from evolved stars and the apparently more rapid destruction in supernova-generated shock waves. Aims. We re-examine some of the key issues relating to dust evolution and processing in the interstellar medium. Methods. We use recent and new constraints from observations, experiments, modelling and theory to re-evaluate dust formation in the interstellar medium (ISM). Results. We find that the discrepancy between the dust formation and destruction time-scales may not be as significant as has previously been assumed because of the very large uncertainties involved. Conclusions. The derived silicate dust lifetime could be compatible with its injection time-scale, given the inherent uncertainties in the dust lifetime calculation. The apparent need to re-form significant quantities of silicate dust in the tenuous interstellar medium may therefore not be a strong requirement. Carbonaceous matter, on the other hand, appears to be rapidly recycled in the ISM and, in contrast to silicates, there are viable mechanisms for its re-formation in the ISM.

EXOS research on master controllers for robotic devices

Science.gov (United States)

Marcus, Beth A.; An, Ben; Eberman, Brian

1992-01-01

Two projects are currently being conducted by EXOS under the Small Business Innovation Research (SBIR) program with NASA. One project will develop a force feedback device for controlling robot hands, the other will develop an elbow and shoulder exoskeleton which can be integrated with other EXOS devices to provide whole robot arm and hand control. Aspects covered are the project objectives, important research issues which have arisen during the developments, and interim results of the projects. The Phase 1 projects currently underway will result in hardware prototypes and identification of research issues required for complete system development and/or integration.

Agglomeration of dust in convective clouds initialized by nuclear bursts

Science.gov (United States)

Bacon, D. P.; Sarma, R. A.

Convective clouds initialized by nuclear bursts are modeled using a two-dimensional axisymmetric cloud model. Dust transport through the atmosphere is studied using five different sizes ranging from 1 to 10,000 μm in diameter. Dust is transported in the model domain by advection and sedimentation. Water is allowed to condense onto dust particles in regions of supersaturation in the cloud. The agglomeration of dust particles resulting from the collision of different size dust particles is modeled. The evolution of the dust mass spectrum due to agglomeration is modeled using a numerical scheme which is mass conserving and has low implicit diffusion. Agglomeration moves mass from the small particles with very small fall velocity to the larger sizes which fall to the ground more readily. Results indicate that the dust fallout can be increased significantly due to this process. In preliminary runs using stable and unstable environmental soundings, at 30 min after detonation the total dust in the domain was 11 and 30%, respectively, less than a control case without agglomeration.

Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

Science.gov (United States)

Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

2009-12-01

was developed for this task. The dust separation system includes a fluidized bed, an elutriation flask, and a cyclone. The product dust is collected on a membrane filter with 0.45 micrometer pore size. Collection and separation efficiencies, and particle size distribution measurements of the material retained in the various components are tracked as development and tests proceed. Calculations show that respirable-sized particles, if released in a habitat, would remain suspended in the air for extended periods of time. Without active dust control, most of this fine dust would end up in the crew’s lungs. Dust exposure standards, similar to those established for quartz on Earth, will determine the design, mass, power, and cost of dust control systems incorporated into lunar habitats and pressurized rovers.

Particle and impurity control in toroidal fusion devices

International Nuclear Information System (INIS)

Wootton, A.J.

1986-01-01

A review of working particle and impurity control techniques used in and proposed for magnetic fusion devices is presented. The requirements of both present-day machines and envisaged fusion reactors are considered. The various techniques which have been proposed are characterized by whether they affect sources, sinks, or fluxes; in many cases a particular method or device can appear in more than one category. Examples are drawn from published results. The solutions proposed for the large devices which will be operating during the next 5 years are discussed

Models of surface convection and dust clouds in brown dwarfs

International Nuclear Information System (INIS)

Freytag, B; Allard, F; Ludwig, H-G; Homeier, D; Steffen, M

2008-01-01

The influence of dust grains on the atmospheres of brown dwarfs is visible in observed spectra. To investigate what prevents the dust grains from falling down, or how fresh condensable material is mixed up in the atmosphere to allow new grains to form, we performed 2D radiation-hydrodynamics simulations with CO5BOLD of the upper part of the convection zone and the atmosphere containing the dust cloud layers. We find that unlike in models of Cepheids, the convective overshoot does not play a major role. Instead, the mixing in the dust clouds is controlled by gravity waves.

Consumer-grade EEG devices: are they usable for control tasks?

Directory of Open Access Journals (Sweden)

Rytis Maskeliunas

2016-03-01

Full Text Available We present the evaluation of two well-known, low-cost consumer-grade EEG devices: the Emotiv EPOC and the Neurosky MindWave. Problems with using the consumer-grade EEG devices (BCI illiteracy, poor technical characteristics, and adverse EEG artefacts are discussed. The experimental evaluation of the devices, performed with 10 subjects asked to perform concentration/relaxation and blinking recognition tasks, is given. The results of statistical analysis show that both devices exhibit high variability and non-normality of attention and meditation data, which makes each of them difficult to use as an input to control tasks. BCI illiteracy may be a significant problem, as well as setting up of the proper environment of the experiment. The results of blinking recognition show that using the Neurosky device means recognition accuracy is less than 50%, while the Emotiv device has achieved a recognition accuracy of more than 75%; for tasks that require concentration and relaxation of subjects, the Emotiv EPOC device has performed better (as measured by the recognition accuracy by ∼9%. Therefore, the Emotiv EPOC device may be more suitable for control tasks using the attention/meditation level or eye blinking than the Neurosky MindWave device.

Using an Instrumented Drone to Sample Dust Devils

Science.gov (United States)

Jackson, Brian; Lorenz, Ralph; Davis, Karan; Lipple, Brock

2017-10-01

Dust devils are low-pressure, small (many to tens of meters) convective vortices powered by surface heating and rendered visible by lofted dust. Dust devils occur in arid climates on Earth, where they degrade air quality and pose a hazard to small aircraft. They also occur ubiquitously on Mars, where they may dominate the supply of atmospheric dust. Since dust contributes significantly to Mars’ atmospheric heat budget, dust devils probably play an important role in its climate. The dust-lifting capacity of a devil likely depends sensitively on its structure, particularly the wind and pressure profiles, but the exact dependencies are poorly constrained. Thus, the exact contribution to Mars’ atmosphere remains unresolved. Moreover, most previous studies of martian dust devils have relied on passive sampling of the profiles via meteorology packages on landed spacecraft, resulting in random encounter geometries which non-trivially skew the retrieved profiles. Analog studies of terrestrial devils have employed more active sampling (instrumented vehicles or manned aircraft) but have been limited to near-surface (few meters) or relatively high altitude (hundreds of meters) sampling. Unmanned aerial vehicles (UAVs) or drones, combined with miniature, digital instrumentation, promise a novel and uniquely powerful platform from which to sample dust devils via (relatively) controlled geometries at a wide variety of altitudes. In this presentation, we will describe a pilot study using an instrumented quadcopter on an active field site in southeastern Oregon, which (to our knowledge) has not previously been surveyed for dust devils. We will present preliminary results from the resulting encounters, including stereo image analysis and encounter footage collected onboard the drone.

AmbiGaze : direct control of ambient devices by gaze

OpenAIRE

Velloso, Eduardo; Wirth, Markus; Weichel, Christian; Abreu Esteves, Augusto Emanuel; Gellersen, Hans-Werner Georg

2016-01-01

Eye tracking offers many opportunities for direct device control in smart environments, but issues such as the need for calibration and the Midas touch problem make it impractical. In this paper, we propose AmbiGaze, a smart environment that employs the animation of targets to provide users with direct control of devices by gaze only through smooth pursuit tracking. We propose a design space of means of exposing functionality through movement and illustrate the concept through four prototypes...

Life cycle and reproduction of house-dust mites: environmental factors influencing mite populations.

Science.gov (United States)

Hart, B J

1998-01-01

An understanding of the life cycle of house-dust mites, as well as environmental factors influencing mite populations, can be exploited in mite control. The most important limiting factor for house-dust-mite populations is air humidity. House-dust mites osmoregulate through the cuticle and therefore require a high ambient air humidity to prevent excessive water loss. In addition, the supracoxal glands actively take up ambient water vapour, and the protonynph stage of the life cycle is resistant to desiccation. Larger house-dust-mite populations are found when the absolute indoor air humidity is above 7 g/kg (45% relative humidity at 20 degrees C). Consequently, ventilation by air-conditioning systems is being developed as a means of control. A number of other aspects of the domestic environment are also being manipulated in an integrated approach to render the habitat less suitable for mites. The potential exists for developing models for house-dust mite populations, environmental characteristics, and the effects of various approaches to control.

Testing Dust Control Preparation with Respect to Mine Employee Exposure to Inhalling Chemical Agents

Directory of Open Access Journals (Sweden)

Eugeniusz Orszulik

2013-01-01

Full Text Available This paper presents the results of tests used in dust hazard prevention for air-water spraying devices in collieries. The purpose of the tests was to evaluate mine employees’ exposure to inhalling chemical agents when the ZWILKOP ZW-10 preparation is used. The paper presents the results of the measurements of concentration, in a mine atmosphere, of the following chemical agents: hazardous substances 2-(2-butoxyethoxyethanol and 2-ethylhexan-1-ol, constituting ingredients of the preparation at mine employees’ workstations. The tests were performed during work related to the mining of coal in inclined drift C31, seam 415/1-2 on the premises of “Borynia-Zofiówka-Jastrzębie” Hard Coal Mine, Jastrzębie-Zdrój, Poland, using the TELESTO mist systems. Using aqueous solutions for the preparation at concentrations of 15 and 20‰ causes no exceedance of the allowable mine air concentrations for the chemical agents tested.

Past, present and future of dust research at the Elliot Lake Laboratory

International Nuclear Information System (INIS)

Grenier, M.; Bigu, J.

1985-12-01

A brief history of the dust research work at the Elliot Lake Laboratory is given. Two decades of dust research work are studied and reviewed. This review clearly shows where, when, and with what intensity various components of dust research were performed. From the data presented here, it is suggested that a major portion of the future efforts be aimed at research directed towards the control and suppression of dust in underground mines

Assessment of state-of-the-art dust emission scheme in GEOS

Science.gov (United States)

Darmenov, A.; Liu, X.; Prigent, C.

2017-12-01

The GEOS modeling system has been extended with state-of-the-art parameterization of dust emissions based on the vertical flux formulation described in Kok et al., 2014. The new dust scheme was coupled with the GOCART and MAM aerosol models. In the present study we compared dust emissions, aerosol optical depth (AOD) and radiative fluxes from GEOS experiments with the standard and new dust emissions. AOD from the model experiments were also compared with AERONET and satellite based AOD product. Based on this comparative analysis we concluded that the new parameterization improved the GEOS capability to model dust aerosols originating from African sources, however it led to overestimation of dust emissions from Asian and Middle-Eastern sources. Further regional tuning of key parameters controlling the threshold friction velocity may be required in order to attain more definitive and uniform improvement in the dust modeling skill with the newly implemented dust emissions scheme.

Nuclear reactor power control device

International Nuclear Information System (INIS)

Koshi, Yuji; Sakata, Akira; Karatsu, Hiroyuki.

1987-01-01

Purpose: To control abrupt changes in neutron fluxes by feeding back a correction signal obtained from a deviation between neutron fluxes and heat fluxes for changing the reactor core flow rate to a recycling flow rate control system upon abrupt power change of a nuclear reactor. Constitution: In addition to important systems, that is, a reactor pressure control system and a recycling control system in the power control device of a BWR type power plant, a control circuit for feeding back a deviation between neutron fluxes and heat fluxes to a recycling flow rate control system is disposed. In the suppression circuit, a deviation signal is prepared in an adder from neutron flux and heat flux signals obtained through a primary delay filter. The deviation signal is passed through a dead band and an advance/delay filter into a correction signal, which is adapted to be fed back to the recycling flow rate control system. As a result, the reactor power control can be conducted smoothly and it is possible to effectively suppress the abrupt change or over shoot of the neutron fluxes and abrupt power change. (Kamimura, M.)

Re-Active Passive devices for control of noise transmission through a panel

Science.gov (United States)

Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Dan

2008-01-01

Re-Active Passive devices have been developed to control low-frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The Re-Active Passive device uses passive constrained layer damping to cover relatively high-frequency range (>150 Hz), reactive distributed vibration absorber to cover the medium-frequency range (50-200 Hz), and active control for controlling low frequencies (transmission through a panel mounted in the Transmission Loss Test Facility at Virginia Tech. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three Re-Active Passive devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 g to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

DUST PROPERTIES OF LOCAL DUST-OBSCURED GALAXIES WITH THE SUBMILLIMETER ARRAY

Energy Technology Data Exchange (ETDEWEB)

Hwang, Ho Seong; Andrews, Sean M.; Geller, Margaret J., E-mail: hhwang@cfa.harvard.edu, E-mail: sandrews@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-11-01

We report Submillimeter Array observations of the 880 μm dust continuum emission for four dust-obscured galaxies (DOGs) in the local universe. Two DOGs are clearly detected with S{sub ν}(880 μm) =10-13 mJy and S/N > 5, but the other two are not detected with 3σ upper limits of S{sub ν}(880 μm) =5-9 mJy. Including an additional two local DOGs with submillimeter data from the literature, we determine the dust masses and temperatures for six local DOGs. The infrared luminosities and dust masses for these DOGs are in the ranges of 1.2-4.9 × 10{sup 11}(L{sub ☉}) and 4-14 × 10{sup 7}(M{sub ☉}), respectively. The dust temperatures derived from a two-component modified blackbody function are 23-26 K and 60-124 K for the cold and warm dust components, respectively. Comparison of local DOGs with other infrared luminous galaxies with submillimeter detections shows that the dust temperatures and masses do not differ significantly among these objects. Thus, as argued previously, local DOGs are not a distinctive population among dusty galaxies, but simply represent the high-end tail of the dust obscuration distribution.

An LDEF 2 dust instrument for discrimination between orbital debris and natural particles in near-Earth space

Science.gov (United States)

Tuzzolino, A. J.; Simpson, J. A.; Mckibben, R. B.; Voss, H. D.; Gursky, H.

1993-01-01

The characteristics of a space dust instrument which would be ideally suited to carry out near-Earth dust measurements on a possible Long Duraction Exposure Facility reflight mission (LDEF 2) is discussed. As a model for the trajectory portion of the instrument proposed for LDEF 2, the characteristics of a SPAce DUSt instrument (SPADUS) currently under development for flight on the USA ARGOS mission to measure the flux, mass, velocity, and trajectory of near-Earth dust is summarized. Since natural (cosmic) dust and man-made dust particles (orbital debris) have different velocity and trajectory distributions, they are distinguished by means of the SPADUS velocity/trajectory information. The SPADUS measurements will cover the dust mass range approximately 5 x 10(exp -12) g (2 microns diameter) to approximately 1 x 10(exp -5) g (200 microns diameter), with an expected mean error in particle trajectory of approximately 7 deg (isotropic flux). Arrays of capture cell devices positioned behind the trajectory instrumentation would provide for Earth-based chemical and isotopic analysis of captured dust. The SPADUS measurement principles, characteristics, its role in the ARGOS mission, and its application to an LDEF 2 mission are summarized.

Reactor water level control device

International Nuclear Information System (INIS)

Utagawa, Kazuyuki.

1993-01-01

A device of the present invention can effectively control fluctuation of a reactor water level upon power change by reactor core flow rate control operation. That is, (1) a feedback control section calculates a feedwater flow rate control amount based on a deviation between a set value of a reactor water level and a reactor water level signal. (2) a feed forward control section forecasts steam flow rate change based on a reactor core flow rate signal or a signal determining the reactor core flow rate, to calculate a feedwater flow rate control amount which off sets the steam flow rate change. Then, the sum of the output signal from the process (1) and the output signal from the process (2) is determined as a final feedwater flow rate control signal. With such procedures, it is possible to forecast the steam flow rate change accompanying the reactor core flow rate control operation, thereby enabling to conduct preceding feedwater flow rate control operation which off sets the reactor water level fluctuation based on the steam flow rate change. Further, a reactor water level deviated from the forecast can be controlled by feedback control. Accordingly, reactor water level fluctuation upon power exchange due to the reactor core flow rate control operation can rapidly be suppressed. (I.S.)

Electronic adherence monitoring device performance and patient acceptability: a randomized control trial.

Science.gov (United States)

Chan, Amy Hai Yan; Stewart, Alistair William; Harrison, Jeff; Black, Peter Nigel; Mitchell, Edwin Arthur; Foster, Juliet Michelle

2017-05-01

To investigate the performance and patient acceptability of an inhaler electronic monitoring device in a real-world childhood asthma population. Children 6 to 15 years presenting with asthma to the hospital emergency department and prescribed inhaled corticosteroids were included. Participants were randomized to receive a device with reminder features enabled or disabled for use with their preventer. Device quality control tests were conducted. Questionnaires on device acceptability, utility and ergonomics were completed at six months. A total of 1306 quality control tests were conducted; 84% passed pre-issue and 87% return testing. The most common failure reason was actuation under-recording. Acceptability scores were high, with higher scores in the reminder than non-reminder group (median, 5 th -95 th percentile: 4.1, 3.1-5.0 versus 3.7, 2.3-4.8; p 90%) rated the device easy to use. Feedback was positive across five themes: device acceptability, ringtone acceptability, suggestions for improvement, effect on medication use, and effect on asthma control. This study investigates electronic monitoring device performance and acceptability in children using quantitative and qualitative measures. Results indicate satisfactory reliability, although failure rates of 13-16% indicate the importance of quality control. Favorable acceptability ratings support the use of these devices in children.

Method and device for controlling nuclear reactor power

International Nuclear Information System (INIS)

Takigawa, Yukio; Ebata, Shigeo.

1988-01-01

Purpose: To detect and suppress the special power oscillations in the reactor core. Method: Four pairs of LPRM detectors, each pair comprising two detectors are disposed at an identical axial direction of the reactor core and situated at substantially insymmetrical positions at least in longitudinal, vertical and orthogonal directions with respect to the center of te reactor core and LPRM signals from them are inputted into a device for judging special power oscillations. In this case, a standardized mutual relation function is determined on every pair for the respective LPRM signals. Generation of special power oscillations in the reactor core is judged when it is detected that peaks appearing at least in one of the function forms for each pair are negative and have absolute values exceeding a predetermined value and that time of peak is within a predetermined time. The judged signal is inputted to a selected control rod insertion device. The selected control rod insertion device, upon preceiving the signal, inserts selected control rods into the reactor core to suppress the special power oscillations. Accordingly, it is possible to improve the fuel integrity. (Horiuchi, T.)

Collisionless damping of nonlinear dust ion acoustic wave due to dust charge fluctuation

International Nuclear Information System (INIS)

Ghosh, Samiran; Chaudhuri, Tushar K.; Sarkar, Susmita; Khan, Manoranjan; Gupta, M.R.

2002-01-01

A dissipation mechanism for the damping of the nonlinear dust ion acoustic wave in a collisionless dusty plasma consisting of nonthermal electrons, ions, and variable charge dust grains has been investigated. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust ion acoustic wave propagation to be described by the damped Korteweg-de Vries equation. Due to the presence of nonthermal electrons, the dust ion acoustic wave admits both positive and negative potential and it suffers less damping than the dust acoustic wave, which admits only negative potential

Demonstration of a dust control system for boom-type roadheader. Open-file report September 1979-July 1981

International Nuclear Information System (INIS)

Burnett, M.; Pokora, R.J.; Muldoon, T.

1981-09-01

This program was initiated by the Bureau of Mines to quantify the respirable dust problem caused by the use of roadheaders in underground metal-nonmetal mines with special emphasis on this problem in uranium mines. The objective was to develop methods or equipment to alleviate respirable dust and to implement a solution in a mine. Attempts to quantify the dust problem were made by a survey of MSHA records, a survey of State nine enforcement agencies, a survey of mine records, and dust measurements taken at two mines using roadheaders. The results are not conclusive because of limited and sometimes less than useful data; however, the study does indicate that a serious dust problem could and may exist. The report discusses the available data concerning respirable dust problems and presents a solution that can potentially help to solve the problem. The solution requires the use of blowing ventilation, onboard dust extraction at the source, filtration, and continued continued use of water sprays

Bounded dust-acoustic waves in a cylindrically bounded collisional dusty plasma with dust charge variation

International Nuclear Information System (INIS)

Wei Nanxia; Xue Jukui

2006-01-01

Taking into account the boundary, particle collisions, and dust charging effects, dust-acoustic waves in a uniform cylindrically bounded dusty plasma is investigated analytically, and the dispersion relation for the dust-acoustic wave is obtained. The effects of boundary, dust charge variation, particle collision, and dust size on the dust-acoustic wave are discussed in detail. Due to the bounded cylindrical boundary effects, the radial wave number is discrete, i.e., the spectrum is discrete. It is shown that the discrete spectrum, the adiabatic dust charge variation, dust grain size, and the particle collision have significant effects on the dust-acoustic wave

Control rod driving hydraulic device

International Nuclear Information System (INIS)

Sugano, Hiroshi.

1993-01-01

In a control rod driving hydraulic device for an improved BWR type reactor, a bypass pipeline is disposed being branched from a scram pipeline, and a control orifice and a throttle valve are interposed to the bypass pipeline for restricting pressure. Upon occurrence of scram, about 1/2 of water quantity flowing from an accumulator of a hydraulic control unit to the lower surface of a piston of control rod drives by way of a scram pipeline is controlled by the restricting orifice and the throttle valve, by which the water is discharged to a pump suction pipeline or other pipelines by way of the bypass pipeline. With such procedures, a function capable of simultaneously conducting scram for two control rod drives can be attained by one hydraulic control unit. Further, an excessive peak pressure generated by a water hammer phenomenon in the scram pipeline or the control rod drives upon occurrence of scram can be reduced. Deformation and failure due to the excessive peak pressure can be prevented, as well as vibrations and degradation of performance of relevant portions can be prevented. (N.H.)

Protective effect of the DNA vaccine encoding the major house dust mite allergens on allergic inflammation in the murine model of house dust mite allergy

Directory of Open Access Journals (Sweden)

Lee Jaechun

2006-02-01

Full Text Available Abstract Background Vaccination with naked DNA encoding antigen induces cellular and humoral immunity characterized by the activation of specific Th1 cells. Objective To evaluate the effects of vaccination with mixed naked DNA plasmids encoding Der p 1, Der p 2, Der p 3, Der f 1, Der f 2, and Der f 3, the major house dust mite allergens on the allergic inflammation to the whole house dust mites (HDM crude extract. Methods Three hundred micrograms of these gene mixtures were injected into muscle of BALB/c mice. Control mice were injected with the pcDNA 3.1 blank vector. After 3 weeks, the mice were actively sensitized and inhaled with the whole house dust mite extract intranasally. Results The vaccinated mice showed a significantly decreased synthesis of total and HDM-specific IgE compared with controls. Analysis of the cytokine profile of lymphocytes after challenge with HDM crude extract revealed that mRNA expression of interferon-γ was higher in the vaccinated mice than in the controls. Reduced infiltration of inflammatory cells and the prominent infiltration of CD8+ T cells were observed in histology of lung tissue from the vaccinated mice. Conclusion Vaccination with DNA encoding the major house dust mite allergens provides a promising approach for treating allergic responses to whole house dust mite allergens.

Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

Directory of Open Access Journals (Sweden)

Yue Ma

2018-01-01

Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

The Lunar Dust Environment

Science.gov (United States)

Szalay, Jamey Robert

Planetary bodies throughout the solar system are continually bombarded by dust particles, largely originating from cometary activities and asteroidal collisions. Surfaces of bodies with thick atmospheres, such as Venus, Earth, Mars and Titan are mostly protected from incoming dust impacts as these particles ablate in their atmospheres as 'shooting stars'. However, the majority of bodies in the solar system have no appreciable atmosphere and their surfaces are directly exposed to the flux of high speed dust grains. Impacts onto solid surfaces in space generate charged and neutral gas clouds, as well as solid secondary ejecta dust particles. Gravitationally bound ejecta clouds forming dust exospheres were recognized by in situ dust instruments around the icy moons of Jupiter and Saturn, and had not yet been observed near bodies with refractory regolith surfaces before NASA's Lunar Dust and Environment Explorer (LADEE) mission. In this thesis, we first present the measurements taken by the Lunar Dust Explorer (LDEX), aboard LADEE, which discovered a permanently present, asymmetric dust cloud surrounding the Moon. The global characteristics of the lunar dust cloud are discussed as a function of a variety of variables such as altitude, solar longitude, local time, and lunar phase. These results are compared with models for lunar dust cloud generation. Second, we present an analysis of the groupings of impacts measured by LDEX, which represent detections of dense ejecta plumes above the lunar surface. These measurements are put in the context of understanding the response of the lunar surface to meteoroid bombardment and how to use other airless bodies in the solar system as detectors for their local meteoroid environment. Third, we present the first in-situ dust measurements taken over the lunar sunrise terminator. Having found no excess of small grains in this region, we discuss its implications for the putative population of electrostatically lofted dust.

Use of integrity control and automatic start of reserve in a multi-channel temperature and flow rate control device

International Nuclear Information System (INIS)

Strzalkowski, L.

1975-01-01

A way to increase reliability of process quantity control is control of the integrity of the control plants themselves. The possibilities of integrity control on control devices having simply duplicated control channels or working on the basis of the ''two-from-three'' principle are valued. A highly reliable integrity control is possible by use of test signals. For an appropriate control device, structure and function of the assemblies are described. The integrity control device may be used in the water coolant temperature and flow rate control system for all technological channels of the research reactor ''Maria''

Traffic Control Device Evaluation Program : FY 2017

Science.gov (United States)

2018-03-01

This report presents findings on the activities conducted in the Traffic Control Device Evaluation Program during the 2017 fiscal year. The research on sponsored changeable message signs (continued from the previous year) was terminated by the Federa...

Control rod excess withdrawal prevention device

International Nuclear Information System (INIS)

Takayama, Yoshihito.

1992-01-01

Excess withdrawal of a control rod of a BWR type reactor is prevented. That is, the device comprises (1) a speed detector for detecting the driving speed of a control rod, (2) a judging circuit for outputting an abnormal signal if the driving speed is greater than a predetermined level and (3) a direction control valve compulsory closing circuit for controlling the driving direction of inserting and withdrawing a control rod based on an abnormal signal. With such a constitution, when the with drawing speed of a control rod is greater than a predetermined level, it is detected by the speed detector and the judging circuit. Then, all of the direction control valve are closed by way of the direction control valve compulsory closing circuit. As a result, the operation of the control rod is stopped compulsorily and the withdrawing speed of the control rod can be lowered to a speed corresponding to that upon gravitational withdrawal. Accordingly, excess withdrawal can be prevented. (I.S)

Design controls for the medical device industry

CERN Document Server

Teixeira, Marie B

2013-01-01

The second edition of a bestseller, Design Controls for the Medical Device Industry provides a comprehensive review of the latest design control requirements, as well as proven tools and techniques to ensure your company's design control program evolves in accordance with current industry practice. The text assists in the development of an effective design control program that not only satisfies the US FDA Quality System Regulation (QSR) and ISO 9001 and 13485 standards, but also meets today's third-party auditor/investigator expectations and saves you valuable time and money.The author's cont

Motion control, motion sickness, and the postural dynamics of mobile devices.

Science.gov (United States)

Stoffregen, Thomas A; Chen, Yi-Chou; Koslucher, Frank C

2014-04-01

Drivers are less likely than passengers to experience motion sickness, an effect that is important for any theoretical account of motion sickness etiology. We asked whether different types of control would affect the incidence of motion sickness, and whether any such effects would be related to participants' control of their own bodies. Participants played a video game on a tablet computer. In the Touch condition, the device was stationary and participants controlled the game exclusively through fingertip inputs via the device's touch screen. In the Tilt condition, participants held the device in their hands and moved the device to control some game functions. Results revealed that the incidence of motion sickness was greater in the Touch condition than in the Tilt condition. During game play, movement of the head and torso differed as a function of the type of game control. Before the onset of subjective symptoms of motion sickness, movement of the head and torso differed between participants who later reported motion sickness and those that did not. We discuss implications of these results for theories of motion sickness etiology.

An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia

Science.gov (United States)

El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.

2015-01-01

We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532

Ultrasonic Sorter for Handling and Collecting Dust or Soil Particles Separated by Size/Density

Science.gov (United States)

Gonzalez, I.; Pinto, A.

2018-04-01

A new device is proposed consisting of an endless screw attached to a small sorter actuated by ultrasounds where particles collect from soil or dust to be separated and collected in different reservoirs for their return to the Earth.

Coupling Mars' Dust and Water Cycles: Effects on Dust Lifting Vigor, Spatial Extent and Seasonality

Science.gov (United States)

Kahre, M. A.; Hollingsworth, J. L.; Haberle, R. M.; Montmessin, F.

2012-01-01

The dust cycle is an important component of Mars' current climate system. Airborne dust affects the radiative balance of the atmosphere, thus greatly influencing the thermal and dynamical state of the atmosphere. Dust raising events on Mars occur at spatial scales ranging from meters to planet-wide. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. Generally, a low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading were observed by MGS/TES: one peak occurred before northern winter solstice at Ls 200-240, and one peak occurred after northern winter solstice at L(sub s) 305-340. These maxima in dust loading are thought to be associated with transient eddy activity in the northern hemisphere, which has been observed to maximize pre- and post-solstice. Interactive dust cycle studies with Mars General Circulation Models (MGCMs) have included the lifting, transport, and sedimentation of radiatively active dust. Although the predicted global dust loadings from these simulations capture some aspects of the observed dust cycle, there are marked differences between the simulated and observed dust cycles. Most notably, the maximum dust loading is robustly predicted by models to occur near northern winter solstice and is due to dust lifting associated with down slope flows on the flanks of the Hellas basin. Thus far, models have had difficulty simulating the observed pre- and post- solstice peaks in dust loading. Interactive dust cycle studies typically have not included the formation of water ice clouds or their radiative effects. Water ice clouds can influence the dust cycle by scavenging dust from atmosphere and by interacting with solar and infrared radiation

Evaluation of effectiveness of hydrolyzed dextran in treatment of dust-induced bronchitis

Energy Technology Data Exchange (ETDEWEB)

Slinchenko, N.Z.; Filipchenko, L.L.; Volkova, V.M.

1986-05-01

An experimental group and a control group identical in age, work experience, dust exposure and expression of disease were treated for dust-induced bronchitis. The control group received broncholytics, anti-inflammatory preparations and physiotherapy; the experimental group received same treatment plus 200 ml of rheopolyglucin, a 10% solution of dextran (water-soluble polysaccharide of glucose), twice a week for 2 to 3 weeks. In addition to general laboratory and clinical methods of investigation, cytologic analysis of sputum before and after treatment was carried out. Results of experiment are given in 3 tables showing: Dynamics of Allergic Signs after Treatment with Rheopolyglucin, Dynamics of Content of Eosinophils in Blood after Treatment, and Cytologic Characteristics of Mucus of Patients with Dust-Induced Bronchitis. Patients treated with rheopolyglucin improved more than control group in abatement of suppurative process in lungs, strengthening of specific cellular and humoral mechanisms of immune response at level of bronchopulmonary system, increased expulsion of mineral dust from lungs and significant reduction of allergic reaction. Results quantitated in tables prove advantages of adding rheopolyglucin to traditional therapy in treatment of dust-induced bronchitis. 19 refs.

Fractal dust grains in plasma

International Nuclear Information System (INIS)

Huang, F.; Peng, R. D.; Liu, Y. H.; Chen, Z. Y.; Ye, M. F.; Wang, L.

2012-01-01

Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

Re-active Passive (RAP) Devices for Control of Noise Transmission through a Panel

Science.gov (United States)

Carneal, James P.; Giovanardi, Marco; Fuller, Chris R.; Palumbo, Daniel L.

2008-01-01

Re-Active Passive (RAP) devices have been developed to control low frequency (transmission through a panel. These devices use a combination of active, re-active, and passive technologies packaged into a single unit to control a broad frequency range utilizing the strength of each technology over its best suited frequency range. The RAP device uses passive constrained layer damping to cover the relatively high frequency range (>200 Hz), reactive distributed vibration absorber) to cover the medium frequency range (75 to 250 Hz), and active control for controlling low frequencies (transmission through a panel mounted in a transmission loss test facility. Experimental results are presented for the bare panel, and combinations of passive treatment, reactive treatment, and active control. Results indicate that three RAP devices were able to increase the overall broadband (15-1000 Hz) transmission loss by 9.4 dB. These three devices added a total of 285 grams to the panel mass of 6.0 kg, or approximately 5%, not including control electronics.

Design and development of a dust dispersion chamber to quantify the dispersibility of rock dust.

Science.gov (United States)

Perera, Inoka E; Sapko, Michael J; Harris, Marcia L; Zlochower, Isaac A; Weiss, Eric S

2016-01-01

Dispersible rock dust must be applied to the surfaces of entries in underground coal mines in order to inert the coal dust entrained or made airborne during an explosion and prevent propagating explosions. 30 CFR. 75.2 states that "… [rock dust particles] when wetted and dried will not cohere to form a cake which will not be dispersed into separate particles by a light blast of air …" However, a proper definition or quantification of "light blast of air" is not provided. The National Institute for Occupational Safety and Health (NIOSH) has, consequently, designed a dust dispersion chamber to conduct quantitative laboratory-scale dispersibility experiments as a screening tool for candidate rock dusts. A reproducible pulse of air is injected into the chamber and across a shallow tray of rock dust. The dust dispersed and carried downwind is monitored. The mass loss of the dust tray and the airborne dust measurements determine the relative dispersibility of the dust with respect to a Reference rock dust. This report describes the design and the methodology to evaluate the relative dispersibility of rock dusts with and without anti-caking agents. Further, the results of this study indicate that the dispersibility of rock dusts varies with particle size, type of anti-caking agent used, and with the untapped bulk density. Untreated rock dusts, when wetted and dried forming a cake that was much less dispersible than the reference rock dust used in supporting the 80% total incombustible content rule.

Scalability of voltage-controlled filamentary and nanometallic resistance memory devices.

Science.gov (United States)

Lu, Yang; Lee, Jong Ho; Chen, I-Wei

2017-08-31

Much effort has been devoted to device and materials engineering to realize nanoscale resistance random access memory (RRAM) for practical applications, but a rational physical basis to be relied on to design scalable devices spanning many length scales is still lacking. In particular, there is no clear criterion for switching control in those RRAM devices in which resistance changes are limited to localized nanoscale filaments that experience concentrated heat, electric current and field. Here, we demonstrate voltage-controlled resistance switching, always at a constant characteristic critical voltage, for macro and nanodevices in both filamentary RRAM and nanometallic RRAM, and the latter switches uniformly and does not require a forming process. As a result, area-scalability can be achieved under a device-area-proportional current compliance for the low resistance state of the filamentary RRAM, and for both the low and high resistance states of the nanometallic RRAM. This finding will help design area-scalable RRAM at the nanoscale. It also establishes an analogy between RRAM and synapses, in which signal transmission is also voltage-controlled.

Wood Dust

Science.gov (United States)

Learn about wood dust, which can raise the risk of cancers of the paranasal sinuses and nasal cavity. High amounts of wood dust are produced in sawmills, and in the furniture-making, cabinet-making, and carpentry industries.

Dust collector

Energy Technology Data Exchange (ETDEWEB)

Sahourin, H.

1988-03-22

This invention relates to a dust collector or filter which may be used for large volume cleaning air for gases or for separating out industrial byproducts such as wood chips, sawdust, and shavings. It relies on filtration or separation using only a uniquely configured medium. A primary, but not exclusive, purpose of the invention is to enable very large throughput, capable of separating or filtering of gases containing up to three or more tons of byproduct with a minimum pressure-drop across the device. No preliminary cycloning, to remove major particulates is necessary. The collector generally comprises a continuous and integral filter medium which is suspended from a plurality of downwardly extending frames forming a series of separate elements having a triangular cross-section, each element being relatively wide at the top and narrow at the bottom to define, between adjacent elements, a divergent collecting space which is wide at the bottom. 11 figs.

Thirteen years of Aeolian dust dynamics in a desert region (Negev desert, Israel): analysis of horizontal and vertical dust flux, vertical dust distribution and dust grain size

NARCIS (Netherlands)

Offer, Z.Y.; Goossens, D.

2004-01-01

At Sede Boqer (northern Negev desert, Israel), aeolian dust dynamics have been measured during the period 1988–2000. This study focuses on temporal records of the vertical and horizontal dust flux, the vertical distribution of the dust particles in the atmosphere, and the grain size of the

Control device for a nuclear reactor with a multitude of control rods, extending into the reactor core from above, with linear drive mechanisms and additional gripper devices

International Nuclear Information System (INIS)

Bevilacqua, F.

1979-01-01

The components of the additional gripper devices with magnetically operated finger-shaped latches are separated from the also magnetically operated latches of the linear drive mechanisms in order to avoid common-mode failures when fast shutdown is required. Only part of the safety rods are held by the additional gripping devices in the withdrawn position. There is provided for recording elements indicating positively which one of the safety locks is gearing with the control rods. At the upper end of each control rod there is a coupling head held by electromagnetically operated locking devices in the withdrawn position, if control power is available. (DG) [de

Electronic control devices

International Nuclear Information System (INIS)

Hartill, D.L.

1981-01-01

The subject of these lectures is the translation of information from particle detectors to computers. Large solid angle general purpose detectors at the intersection regions of high energy e+e- storage rings and pp and pp storage rings are discussed. Three choices for data acquisition are reviewed: use CAMAC (Computer Aided Measurement and Control), start from scratch and design a system, or wait for the final version of the proposed FASTBUS to be developed. The do-it-yourself procedure includes designs of drift chamber discriminator, time to amplitude converter, and data card block diagram. Trigger systems, the fast decision making systems judging an event interesting enough for a read-out cycle to be initiated, are discussed. Finally, a FASTBUS system layout, with its goals of minimum bus speed, general system topologies, and support multiple smart devices is given

Quantitative detection of mass concentration of sand-dust storms via wind-profiling radar and analysis of Z- M relationship

Science.gov (United States)

Wang, Minzhong; Ming, Hu; Ruan, Zheng; Gao, Lianhui; Yang, Di

2018-02-01

With the aim to achieve quantitative monitoring of sand-dust storms in real time, wind-profiling radar is applied to monitor and study the process of four sand-dust storms in the Tazhong area of the Taklimakan Desert. Through evaluation and analysis of the spatial-temporal distribution of reflectivity factor, it is found that reflectivity factor ranges from 2 to 18 dBz under sand-dust storm weather. Using echo power spectrum of radar vertical beams, sand-dust particle spectrum and sand-dust mass concentration at the altitude of 600 ˜ 1500 m are retrieved. This study shows that sand-dust mass concentration reaches 700 μg/m3 under blowing sand weather, 2000 μg/m3 under sand-dust storm weather, and 400 μg/m3 under floating dust weather. The following equations are established to represent the relationship between the reflectivity factor and sand-dust mass concentration: Z = 20713.5 M 0.995 under floating dust weather, Z = 22988.3 M 1.006 under blowing sand weather, and Z = 24584.2 M 1.013 under sand-dust storm weather. The retrieval results from this paper are almost consistent with previous monitoring results achieved by former researchers; thus, it is implied that wind-profiling radar can be used as a new reference device to quantitatively monitor sand-dust storms.

SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures.

Science.gov (United States)

Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

2017-04-01

Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9 m -by-10 m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user's wrist is stationary.

Real-Time Occupant Based Plug-in Device Control Using ICT in Office Buildings

Directory of Open Access Journals (Sweden)

Woo-Bin Bae

2016-03-01

Full Text Available The purpose of this study is to reduce the unnecessary plug loads used by computers, monitors, and computer peripheral devices, all of which account for more than 95% of the entire plug loads of an office building. To this end, an occupant-based plug-in device control (OBC-P software was developed. The OBC-P software collects real-time information about the presence or absence of occupants who are connected to the access point through the Wifi and controls the power of monitors or computers, while a standby power off device controls computer peripheral devices. To measure the plug load saving of the occupant-based plug-in device control, an experiment was conducted, targeting 10 occupants of three research labs of the graduate school, for two weeks. The experiment results showed that it could save the plug loads of monitors and computer peripheral devices by 15% in the Awake mode, and by 26% in the Sleep mode.

Development of a Laser Ablation System Kit (LASK) for Tokamak in vessel tritium and dust inventory control

International Nuclear Information System (INIS)

Hernandez, C.; Roche, H.; Pocheau, C.; Grisolia, C.; Gargiulo, L.; Semerok, A.; Vatry, A.; Delaporte, P.; Mercadier, L.

2009-01-01

During Tokamak operation, Plasma Facing Components (PFCs) are subjected to severe interaction with plasma. As a consequence and independently of the PFCs composition, materials eroded and then re-deposited in the form of layers on the surfaces, can flake and produce dusts. These fragile structures are able to trap part of the hydrogenated species (tritium for example) in vessel inventory. For safety reasons, it is mandatory to measure and to control vessel dust and tritium inventory. Up to now, laser techniques are a part of the most promising methods able to solve these ITER open issues. Of special interest are laser systems loaded on a miniature tool that can be attached to a Multi Purpose Deployer (MPD) and used for laser treatments (detritiation and other), for PFCs chemical analysis as well as for micro particles recovery of dust produced during laser ablation. Such a system (Laser Ablation System Kit: LASK) is currently under development at IRFM and the following presentation will describe the current achievements of this project and the perspectives. In this paper, we will present an innovative compact system, which, loaded on a Multi Purpose Deployer, could allow operation in a harsh environment (pressure range from atmospheric to Ultra High Vacuum and temperature up to 120 deg. C). According to the process conditions, different treatments can be performed: at low laser fluence, PFCs thermal treatment will be expected, while at high laser fluence material will be ablated allowing Dust (and T) recovery as well as chemical analysis of material. This 'in-line' chemical analysis based on Laser Induced Breakdown Spectroscopy (LIBS) enables the ablation process to be controlled and preserves the substrate integrity. The paper will be focussed on the methodology followed during the LASK development and the method used to determine a laser process window able to remove co-deposited film without damaging the bulk material and taking into account external parameter

A Multiposture Locomotor Training Device with Force-Field Control

Directory of Open Access Journals (Sweden)

Jianfeng Sui

2014-11-01

Full Text Available This paper introduces a multiposture locomotor training device (MPLTD with a closed-loop control scheme based on joint angle feedback, which is able to overcome various difficulties resulting from mechanical vibration and the weight of trainer to achieve higher accuracy trajectory. By introducing the force-field control scheme used in the closed-loop control, the device can obtain the active-constrained mode including the passive one. The MPLTD is mainly composed of three systems: posture adjusting and weight support system, lower limb exoskeleton system, and control system, of which the lower limb exoskeleton system mainly includes the indifferent equilibrium mechanism with two degrees of freedom (DOF and the driving torque is calculated by the Lagrangian function. In addition, a series of experiments, the weight support and the trajectory accuracy experiment, demonstrate a good performance of mechanical structure and the closed-loop control.

Characterization of airborne float coal dust emitted during continuous mining, longwall mining and belt transport.

Science.gov (United States)

Shahan, M R; Seaman, C E; Beck, T W; Colinet, J F; Mischler, S E

2017-09-01

Float coal dust is produced by various mining methods, carried by ventilating air and deposited on the floor, roof and ribs of mine airways. If deposited, float dust is re-entrained during a methane explosion. Without sufficient inert rock dust quantities, this float coal dust can propagate an explosion throughout mining entries. Consequently, controlling float coal dust is of critical interest to mining operations. Rock dusting, which is the adding of inert material to airway surfaces, is the main control technique currently used by the coal mining industry to reduce the float coal dust explosion hazard. To assist the industry in reducing this hazard, the Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health initiated a project to investigate methods and technologies to reduce float coal dust in underground coal mines through prevention, capture and suppression prior to deposition. Field characterization studies were performed to determine quantitatively the sources, types and amounts of dust produced during various coal mining processes. The operations chosen for study were a continuous miner section, a longwall section and a coal-handling facility. For each of these operations, the primary dust sources were confirmed to be the continuous mining machine, longwall shearer and conveyor belt transfer points, respectively. Respirable and total airborne float dust samples were collected and analyzed for each operation, and the ratio of total airborne float coal dust to respirable dust was calculated. During the continuous mining process, the ratio of total airborne float coal dust to respirable dust ranged from 10.3 to 13.8. The ratios measured on the longwall face were between 18.5 and 21.5. The total airborne float coal dust to respirable dust ratio observed during belt transport ranged between 7.5 and 21.8.

Quantifying Anthropogenic Dust Emissions

Science.gov (United States)

Webb, Nicholas P.; Pierre, Caroline

2018-02-01

Anthropogenic land use and land cover change, including local environmental disturbances, moderate rates of wind-driven soil erosion and dust emission. These human-dust cycle interactions impact ecosystems and agricultural production, air quality, human health, biogeochemical cycles, and climate. While the impacts of land use activities and land management on aeolian processes can be profound, the interactions are often complex and assessments of anthropogenic dust loads at all scales remain highly uncertain. Here, we critically review the drivers of anthropogenic dust emission and current evaluation approaches. We then identify and describe opportunities to: (1) develop new conceptual frameworks and interdisciplinary approaches that draw on ecological state-and-transition models to improve the accuracy and relevance of assessments of anthropogenic dust emissions; (2) improve model fidelity and capacity for change detection to quantify anthropogenic impacts on aeolian processes; and (3) enhance field research and monitoring networks to support dust model applications to evaluate the impacts of disturbance processes on local to global-scale wind erosion and dust emissions.

Autotuning of PID controller by means of human machine interface device

Directory of Open Access Journals (Sweden)

Michał Awtoniuk

2017-06-01

Full Text Available More and more control systems are based on industry microprocessors like PLC controllers (Programmable Logic Controller. The most commonly used control algorithm is PID (Proportional-Integral-Derivative algorithm. Autotuning procedure is not available in every PLC. These controllers are typically used in cooperation with HMI (Human Machine Interface devices. In the study two procedures of autotuning of the PID controller were implemented in the HMI device: step method and relay method. Six tuning rules for step methods and one for relay method were chosen. The autotuning procedures on simulated controlled object and PLC controller without build-in autotuning were tested. The object of control was first order system plus time delay.

Increasing Severity of Pneumoconiosis Among Younger Former US Coal Miners Working Exclusively Under Modern Dust-Control Regulations.

Science.gov (United States)

Graber, Judith M; Harris, Gerald; Almberg, Kirsten S; Rose, Cecile S; Petsonk, Edward L; Cohen, Robert A

2017-06-01

Coal workers' pneumoconiosis (CWP) steadily declined among US miners following dust control regulations in 1970. In 2000, severe forms of this disease reemerged among young miners, and are well described among working-but not former-miners. Black lung benefits program (BLBP) data (2001 to 2013) were used to estimate respiratory disease burden among former miners including: (1) CWP (simple; advanced CWP, and progressive massive fibrosis [CWP/PMF]); and (2) respiratory impairment (FEV1 percent reference: mild, moderate, ≥moderately-severe). Among 24,686 claimants, 8.5% had advanced CWP/PMF; prevalence was highest among younger (less than or equal to 56 years: 10.8%) and older (greater than 70 years: 8.4%) miners and those who began work after versus before 1970 (8.3% vs. 4.0%). BLBP claims provide potentially useful data for monitoring the burden and severity of coal mine dust lung disease, and assessing efficacy of protective regulations.

Occupational exposure to wood dust and risk of nasal and nasopharyngeal cancer: A case-control study among men in four nordic countries-With an emphasis on nasal adenocarcinoma.

Science.gov (United States)

Siew, Sie Sie; Martinsen, Jan Ivar; Kjaerheim, Kristina; Sparén, Pär; Tryggvadottir, Laufey; Weiderpass, Elisabete; Pukkala, Eero

2017-12-15

The current study aims to provide stronger evidence to aid in our understanding of the role of cumulative occupational exposure to (softwood-dominated) mixed wood dust in aetiology of nasal cancer. We included broad exposure occurred in a range of wood-processing occupation across varied industries in four Nordic countries. A population-based case-control study was conducted on all male cases with nasal adenocarcinoma (393 cases), other types of nasal cancer (2,446) and nasopharyngeal cancer (1,747) diagnosed in Finland, Sweden, Norway and Iceland between 1961 and 2005. For each case, five male controls, who were alive at the time of diagnosis of the case (index date), were randomly selected, matched by birth-year and country. Cumulative exposures (CE)s to wood dust and formaldehyde before the index date were quantified based on a job-exposure matrix linked to occupational titles derived from population censuses. Hazard ratios (HRs) for the CE of wood dust were estimated by conditional logistic regression, adjusted for CE to formaldehyde and 95% confidence intervals (CIs) were calculated. There was an increasing risk of nasal adenocarcinoma related to wood dust exposure. The HR in the highest CE category of wood dust (≥ 28.82 mg/m 3 -years) was 16.5 (95% CI 5.05-54.1). Neither nonadenocarcinoma of the nose nor nasopharyngeal cancer could be linked to wood dust exposure. CE to softwood-dominated mixed wood dusts is strongly linked with elevated risk in nasal adenocarcinoma but not with other types of nasal or nasopharyngeal cancer. © 2017 UICC.

Development and control of a magnetorheological haptic device for robot assisted surgery.

Science.gov (United States)

Shokrollahi, Elnaz; Goldenberg, Andrew A; Drake, James M; Eastwood, Kyle W; Kang, Matthew

2017-07-01

A prototype magnetorheological (MR) fluid-based actuator has been designed for tele-robotic surgical applications. This device is capable of generating forces up to 47 N, with input currents ranging from 0 to 1.5 A. We begin by outlining the physical design of the device, and then discuss a novel nonlinear model of the device's behavior. The model was developed using the Hammerstein-Wiener (H-W) nonlinear black-box technique and is intended to accurately capture the hysteresis behavior of the MR-fluid. Several experiments were conducted on the device to collect estimation and validation datasets to construct the model and assess its performance. Different estimating functions were used to construct the model, and their effectiveness is assessed based on goodness-of-fit and final-prediction-error measurements. A sigmoid network was found to have a goodness-of-fit of 95%. The model estimate was then used to tune a PID controller. Two control schemes were proposed to eliminate the hysteresis behavior present in the MR fluid device. One method uses a traditional force feedback control loop and the other is based on measuring the magnetic field using a Hall-effect sensor embedded within the device. The Hall-effect sensor scheme was found to be superior in terms of cost, simplicity and real-time control performance compared to the force control strategy.

Plasma surface interactions in controlled fusion devices

Energy Technology Data Exchange (ETDEWEB)

Ghendrih, Ph.; Becoulet, M.; Costanzo, L. [and others

2000-07-01

This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak.

Plasma surface interactions in controlled fusion devices

International Nuclear Information System (INIS)

Ghendrih, Ph.; Becoulet, M.; Costanzo, L.

2000-07-01

This report brings together all the contributions of EURATOM/CEA association to the 14. international conference on plasma surface interactions in controlled fusion devices. 24 papers are presented and they deal mainly with the ergodic divertor and the first wall of Tore-supra tokamak

A simple optical fibre-linked remote control system for multiple devices

Indian Academy of Sciences (India)

We report on the development of a simple control system which can handle multiple devices through an optical fibre data link. The devices are controlled using a set of DACs through serial data communication via a serial port of a PC. Serial data from the PC get converted to parallel mode using a homemade “serial in ...

Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations

Science.gov (United States)

Singh, Aditi; Iyengar, Gopal R.; George, John P.

2016-05-01

Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.

Control rod position detection device

International Nuclear Information System (INIS)

Akita, Haruo; Ogiwara, Sakae.

1996-01-01

The device of the present invention is used in a back-up shut down system of an LMFBR type reactor which is easy for maintenance, has high reliability and can recognize the position of control rods accurately. Namely, a permanent magnet is disposed to a control rod extension tube connected to the lower portion of the control rod. The detector guide tube is disposed in the vicinity of the control rod extension tube. A detector having a detection coil is inserted into a detector tube. With such constitution, the control rod can be detected at one position using the following method. (1) the movement of the magnetic field of the permanent magnet is detected by the detection coil. (2) a plurality of grooves are formed on the control rod extension tube, and the movement of the grooves is detected. In addition, the detection coil is inserted into the detector guide tube, and the signals from the detection coil are inputted to a signal processing circuit disposed at the outside of the reactor vessel using an MI cable to enable the maintenance of the detector. Further, if the detector comprises a detection coil and an excitation coil, the position of a dropped control rod can be recognized at a plurality of points. (I.S.)

[Microcomputer control of a LED stimulus display device].

Science.gov (United States)

Ohmoto, S; Kikuchi, T; Kumada, T

1987-02-01

A visual stimulus display system controlled by a microcomputer was constructed at low cost. The system consists of a LED stimulus display device, a microcomputer, two interface boards, a pointing device (a "mouse") and two kinds of software. The first software package is written in BASIC. Its functions are: to construct stimulus patterns using the mouse, to construct letter patterns (alphabet, digit, symbols and Japanese letters--kanji, hiragana, katakana), to modify the patterns, to store the patterns on a floppy disc, to translate the patterns into integer data which are used to display the patterns in the second software. The second software package, written in BASIC and machine language, controls display of a sequence of stimulus patterns in predetermined time schedules in visual experiments.

Reactor feedwater control device

International Nuclear Information System (INIS)

Koshi, Yuji.

1993-01-01

In the device of the present invention, an excess response is not caused in a reactor feed water system even when voids are fluctuated by using an actual water level signal as a reactor water level signal. That is, a standard water level signal and a reactor water level signal are inputted to a comparator. An adder adds water level difference signal outputted from the comparator and mismatch flow rate signal prepared by multiplying the difference between a main steam flow rate signal and a feed water flow rate signal by a mismatch gain. A feed water controller integrates the added signal and outputs flow rate demand signal. A feed water system receives the flow rate demand signal as input. A water level calculation means is disposed to such a device for calculating an actual water level based on the change of coolant possessing amount of the reactor, and the output thereof is defined as a reactor water level signal. With such procedures, excessive elevation of water level of the reactor can be prevented even upon occurrence of void fluctuation phenomenon or the like in the reactor such as upon sole scram operation. Accordingly, plant shut down caused thereby can be avoided safely. (I.S.)

Fuel control device for various gas turbine configurations

Energy Technology Data Exchange (ETDEWEB)

Stearns, C F; Tutherly, H W

1980-09-29

The hydromechanic fuel control device can be adapted for various engine configurations as for example turbofan-, turbopro-, and turboshaft engines by providing those elements which are common for all engine configurations in the main housing and a detachable block for each individual configuration with all control elements and flow channels necessary for the respective configuration.

Non-Hebbian learning implementation in light-controlled resistive memory devices.

Science.gov (United States)

Ungureanu, Mariana; Stoliar, Pablo; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E

2012-01-01

Non-Hebbian learning is often encountered in different bio-organisms. In these processes, the strength of a synapse connecting two neurons is controlled not only by the signals exchanged between the neurons, but also by an additional factor external to the synaptic structure. Here we show the implementation of non-Hebbian learning in a single solid-state resistive memory device. The output of our device is controlled not only by the applied voltages, but also by the illumination conditions under which it operates. We demonstrate that our metal/oxide/semiconductor device learns more efficiently at higher applied voltages but also when light, an external parameter, is present during the information writing steps. Conversely, memory erasing is more efficiently at higher applied voltages and in the dark. Translating neuronal activity into simple solid-state devices could provide a deeper understanding of complex brain processes and give insight into non-binary computing possibilities.

Device for controlling the hydraulic lifter of drilling unit

Energy Technology Data Exchange (ETDEWEB)

Kraskov, P N

1981-04-10

A device is suggested for controlling the hydraulic lifter of a drilling unit. It contains a throttling valve with cylinder for servocontrol, mechanism for assigning the program for lowering velocity connected to the power cylinder, and oil tank. In order to improve the reliable concentration of the drilling unit by guaranteeing possible alternation for halting descent when the string falls on a projection in the well, the device is equipped with a normally open two-position hydraulically controlled distributor with spring return connected to the working surface of the power cylinder and valve connected to it with logical function of ILI for hydraulic control of the normally opened two-position distributor. The latter connects the working cavity of the servocontrol cylinder with the oil tank.

Climate change and climate systems influence and control the atmospheric dispersion of desert dust: implications for human health

Science.gov (United States)

Griffin, Dale W.; Ragaini, Richard C.

2010-01-01

The global dispersion of desert dust through Earth’s atmosphere is greatly influenced by temperature. Temporal analyses of ice core data have demonstrated that enhanced dust dispersion occurs during glacial events. This is due to an increase in ice cover, which results in an increase in drier terrestrial cover. A shorter temporal analysis of dust dispersion data over the last 40 years has demonstrated an increase in dust transport. Climate systems or events such as the North Atlantic Oscillation, the Indian Ocean subtropical High, Pacific Decadal Oscillation, and El Nino-Sothern Oscillation are known to influence global short-term dust dispersion occurrence and transport routes. Anthropogenic influences on dust transport include deforestation, harmful use of topsoil for agriculture as observed during the American Dust Bowl period, and the creation of dry seas (Aral Sea) and lakes (Lake Owens in California and Lake Chad in North Africa) through the diversion of source waters (for irrigation and drinking water supplies). Constituents of desert dust both from source regions (pathogenic microorganisms, organic and inorganic toxins) and those scavenged through atmospheric transport (i.e., industrial and agricultural emissions) are known to directly impact human and ecosystem health. This presentation will present a review of global scale dust storms and how these events can be both a detriment and benefit to various organisms in downwind environments.

Voltage-Controlled Reconfigurable Spin-Wave Nanochannels and Logic Devices

Science.gov (United States)

Rana, Bivas; Otani, YoshiChika

2018-01-01

Propagating spin waves (SWs) promise to be a potential information carrier in future spintronics devices with lower power consumption. Here, we propose reconfigurable nanochannels (NCs) generated by voltage-controlled magnetic anisotropy (VCMA) in an ultrathin ferromagnetic waveguide for SW propagation. Numerical micromagnetic simulations are performed to demonstrate the confinement of magnetostatic forward volumelike spin waves in NCs by VCMA. We demonstrate that the NCs, with a width down to a few tens of a nanometer, can be configured either into a straight or curved structure on an extended SW waveguide. The key advantage is that either a single NC or any combination of a number of NCs can be easily configured by VCMA for simultaneous propagation of SWs either with the same or different wave vectors according to our needs. Furthermore, we demonstrate the logic operation of a voltage-controlled magnonic xnor and universal nand gate and propose a voltage-controlled reconfigurable SW switch for the development of a multiplexer and demultiplexer. We find that the NCs and logic devices can even be functioning in the absence of the external-bias magnetic field. These results are a step towards the development of all-voltage-controlled magnonic devices with an ultralow power consumption.

A device for automatic photoelectric control of the analytical gap for emission spectrographs

Science.gov (United States)

Dietrich, John A.; Cooley, Elmo F.; Curry, Kenneth J.

1977-01-01

A photoelectric device has been built that automatically controls the analytical gap between electrodes during excitation period. The control device allows for precise control of the analytical gap during the arcing process of samples, resulting in better precision of analysis.

SeleCon: Scalable IoT Device Selection and Control Using Hand Gestures

Science.gov (United States)

Alanwar, Amr; Alzantot, Moustafa; Ho, Bo-Jhang; Martin, Paul; Srivastava, Mani

2018-01-01

Although different interaction modalities have been proposed in the field of human-computer interface (HCI), only a few of these techniques could reach the end users because of scalability and usability issues. Given the popularity and the growing number of IoT devices, selecting one out of many devices becomes a hurdle in a typical smarthome environment. Therefore, an easy-to-learn, scalable, and non-intrusive interaction modality has to be explored. In this paper, we propose a pointing approach to interact with devices, as pointing is arguably a natural way for device selection. We introduce SeleCon for device selection and control which uses an ultra-wideband (UWB) equipped smartwatch. To interact with a device in our system, people can point to the device to select it then draw a hand gesture in the air to specify a control action. To this end, SeleCon employs inertial sensors for pointing gesture detection and a UWB transceiver for identifying the selected device from ranging measurements. Furthermore, SeleCon supports an alphabet of gestures that can be used for controlling the selected devices. We performed our experiment in a 9m-by-10m lab space with eight deployed devices. The results demonstrate that SeleCon can achieve 84.5% accuracy for device selection and 97% accuracy for hand gesture recognition. We also show that SeleCon is power efficient to sustain daily use by turning off the UWB transceiver, when a user’s wrist is stationary. PMID:29683151

Preliminary analysis of hydrogen risk caused by dust in ITER

International Nuclear Information System (INIS)

Cheng Kun; Tong Lili; Cao Xuewu

2012-01-01

A lot of dust will be generated during ITER operation,and hydrogen will be produced by the interaction of hot dust with water in the case of coolant ingress accident. The accumulated hydrogen will bring risk of combustion and explosion,which will damage the device. CFD method has been used to analyze the produced hydrogen in 'wet bypass' scenario, and come to the results that hydrogen will burn and explode at the beginning of the accident, different hydrogen risk will be brought by different coolant leakage, and hydrogen risk will be inert if the leakage is massive.Injecting CO 2 to inert the vacuum vessel has also been discussed, the risk of hydrogen will be suppressed by injecting CO 2 with a large rate at the beginning of accident. (authors)

Parameterizing the interstellar dust temperature

Science.gov (United States)

Hocuk, S.; Szűcs, L.; Caselli, P.; Cazaux, S.; Spaans, M.; Esplugues, G. B.

2017-08-01

The temperature of interstellar dust particles is of great importance to astronomers. It plays a crucial role in the thermodynamics of interstellar clouds, because of the gas-dust collisional coupling. It is also a key parameter in astrochemical studies that governs the rate at which molecules form on dust. In 3D (magneto)hydrodynamic simulations often a simple expression for the dust temperature is adopted, because of computational constraints, while astrochemical modelers tend to keep the dust temperature constant over a large range of parameter space. Our aim is to provide an easy-to-use parametric expression for the dust temperature as a function of visual extinction (AV) and to shed light on the critical dependencies of the dust temperature on the grain composition. We obtain an expression for the dust temperature by semi-analytically solving the dust thermal balance for different types of grains and compare to a collection of recent observational measurements. We also explore the effect of ices on the dust temperature. Our results show that a mixed carbonaceous-silicate type dust with a high carbon volume fraction matches the observations best. We find that ice formation allows the dust to be warmer by up to 15% at high optical depths (AV> 20 mag) in the interstellar medium. Our parametric expression for the dust temperature is presented as Td = [ 11 + 5.7 × tanh(0.61 - log 10(AV) ]χuv1/5.9, where χuv is in units of the Draine (1978, ApJS, 36, 595) UV field.

Resuspension of carbon dust collected in Tore Supra and exposed to turbulent airflow: Controlled experiments and comparison with model

Energy Technology Data Exchange (ETDEWEB)

Peillon, S., E-mail: samuel.peillon@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SCA/LPMA, Saclay, Gif-sur-Yvette 91192 (France); Roynette, A. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SCA/LPMA, Saclay, Gif-sur-Yvette 91192 (France); Grisolia, C. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Gensdarmes, F. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SCA/LPMA, Saclay, Gif-sur-Yvette 91192 (France)

2014-11-15

Highlights: • Mobilization of dust is a key issue for the safety assessment of fusion reactors. • Carbon dust has been collected on the plasma facing components of Tore Supra. • Samples exhibit bimodal particle size distributions. • Samples have been exposed to turbulent airflows for dust resuspension studies. • A comparison with the so-called Rock’n roll resuspension model is proposed. - Abstract: This work presents the results of experiments conducted with carbon microparticles collected in the tokamak Tore Supra in order to characterize their resuspension behaviour from a stainless-steel substrate when exposed to turbulent airflow. Experiments were conducted in a wind tunnel with controlled velocity profiles and monitored environmental conditions. A consequent amount of dust has been collected in the vessel of the tokamak and a bimodal particle size distribution of samples is first demonstrated. Comparison with resuspension of alumina powders with equivalent particle size distributions under turbulent airflow is also discussed. Results for both carbon and alumina microparticles are then compared to a theoretical resuspension model. Data reveal that exposing multilayer deposits with bimodal particle size distributions to low-speed flows (i.e. 3–10 m/s) induces a significant reduction of the mobilized fractions compared to what was predicted by the model. In addition, results helped to highlight some limitations in the model to physically describe changes in the adhesive strength that can occur with a polydisperse deposit.

40 CFR 63.985 - Nonflare control devices used to control emissions from storage vessels and low throughput...

Science.gov (United States)

2010-07-01

... included. (E) For condensers, the design evaluation shall include the final temperature of the stream vapors, the type of condenser, and the design flow rate of the emission stream. (ii) Performance test. A... control device design evaluation or performance test requirements. When using a control device other than...

Controlling Access to Input/Output Peripheral Devices

Directory of Open Access Journals (Sweden)

E. Y. Rodionov

2010-03-01

Full Text Available In this paper the author proposes a system that manages information security policy on enterprise. Problems related to managing information security policy on enterprise and access to peripheral devices in computer systems functioning under control of Microsoft Windows NT operating systems are considered.

Physics of interstellar dust

CERN Document Server

Krugel, Endrik

2002-01-01

The dielectric permeability; How to evaluate grain cross sections; Very small and very big particles; Case studies of Mie calculus; Particle statistics; The radiative transition probability; Structure and composition of dust; Dust radiation; Dust and its environment; Polarization; Grain alignment; PAHs and spectral features of dust; Radiative transport; Diffuse matter in the Milky Way; Stars and their formation; Emission from young stars. Appendices Mathematical formulae; List of symbols.

Algorithm for Public Electric Transport Schedule Control for Intelligent Embedded Devices

Science.gov (United States)

Alps, Ivars; Potapov, Andrey; Gorobetz, Mikhail; Levchenkov, Anatoly

2010-01-01

In this paper authors present heuristics algorithm for precise schedule fulfilment in city traffic conditions taking in account traffic lights. The algorithm is proposed for programmable controller. PLC is proposed to be installed in electric vehicle to control its motion speed and signals of traffic lights. Algorithm is tested using real controller connected to virtual devices and real functional models of real tram devices. Results of experiments show high precision of public transport schedule fulfilment using proposed algorithm.

Dust collection capacity of plants growing in coal mining areas

International Nuclear Information System (INIS)

Maiti, S.K.

1993-01-01

Plant can act as living filter of dust pollution in coal mining areas, where the amount of suspended particulate matter and dust fall rate is very high. Therefore, plant species growing in coal mining areas are classified as evergreen or deciduous with simple and compound leaf basis. The dust arresting capacity of each leaf is measured and expressed in g/m 2 . The study indicated that evergreen plants with simple, pilose surface, like - Alstonia, Ficus cunea, F. benghalensis and Mangifera indica are good dust catcher than evergreen compound leaves of Cassia siamea, Acacia arabica and Leucaena leucocephala. Deciduous with simple leaves, such as Zizyphus mauritiana, F. religiosa, Psidium guyava are also good dust collectors. Suitable plant species also help in quick reclamation of mined out areas; one practical difficulty for establishment of trees as green belts or reclamation purpose, has been incidence of cattle grazing. This study suggested a systematic way of selecting plant species on the basis of their efficiency in dust control and resistance to cattle grazing. (author). 16 refs., 3 tabs

Plant control device

International Nuclear Information System (INIS)

Sato, Masuo; Ono, Makoto.

1995-01-01

A plant control device comprises an intellectual instrumentation group for measuring a predetermined process amount, an intellectual equipment group operating in accordance with a self-countermeasure, a system information space for outputting system information, a system level monitoring and diagnosing information generalization section for outputting system information, a system level maintenance information generalization section for outputting information concerning maintenance, a plant level information space and a plant level information generalization section. Each of them determines a state of the plant autonomously, and when abnormality is detected, each of the intellectual instrumentation, equipments and systems exchange information with each other, to conduct required operations including operations of intellectual robots, as required. Appropriate countermeasures for gauges, equipments and systems can be conducted autonomously at a place where operators can not access to improve reliability of complicate operations in the working site, as well as improve plant safety and reliability. (N.H.)

Risk Assessment to Dust Exposure in Room Maintenance

Directory of Open Access Journals (Sweden)

Saiku Rokhim

2017-04-01

Full Text Available As one of the particulate chemicals, dust could occur in most of the production process and can create interference for workers health and safety. As one of the air pollution sources, dust could became a potential hazard which exist in room maintenances. Protection to workers is a must in order to reduce the risk of respiratory tract syndrome that often could be found in this cases. The aim of this study is to conduct a risk assessment to dust exposure in room maintenance, which held by contractors in PT. X (Persero building in Surabaya. This is an cross sectional study with obsevation approach. The object of this research is the repairing  works. The results indicate that the activities which could produce dust, such as: walls sanding using sandpaper, the tiles dismantle, sawmilling, the wood fiber refining, grinding, mixing and stirring cast  materials, and room cleaning. Dust produced from a variety of works including sanddust, cement, lime, wood and dust mixed with paint. The results show that three types of works considere as high-risk activity (value > 12-25, 3 types of work consider as midle risk activities (value > 5-12, and one activity considered as a low-risk work (grades 1-5. The dusk factors controlling should be held regularly, in order to minimize the risk leveln againts the workers.

The Continuous Monitoring of Desert Dust using an Infrared-based Dust Detection and Retrieval Method

Science.gov (United States)

Duda, David P.; Minnis, Patrick; Trepte, Qing; Sun-Mack, Sunny

2006-01-01

Airborne dust and sand are significant aerosol sources that can impact the atmospheric and surface radiation budgets. Because airborne dust affects visibility and air quality, it is desirable to monitor the location and concentrations of this aerosol for transportation and public health. Although aerosol retrievals have been derived for many years using visible and near-infrared reflectance measurements from satellites, the detection and quantification of dust from these channels is problematic over bright surfaces, or when dust concentrations are large. In addition, aerosol retrievals from polar orbiting satellites lack the ability to monitor the progression and sources of dust storms. As a complement to current aerosol dust retrieval algorithms, multi-spectral thermal infrared (8-12 micron) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Meteosat-8 Spinning Enhanced Visible and Infrared Imager (SEVIRI) are used in the development of a prototype dust detection method and dust property retrieval that can monitor the progress of Saharan dust fields continuously, both night and day. The dust detection method is incorporated into the processing of CERES (Clouds and the Earth s Radiant Energy System) aerosol retrievals to produce dust property retrievals. Both MODIS (from Terra and Aqua) and SEVERI data are used to develop the method.

Efficacy evaluation of a pollen blocker cream against dust-mite allergy: A multicenter, randomized, double-blind, placebo-controlled crossover trial.

Science.gov (United States)

Li, Yanqing; Cheng, Lei; Chen, Xiaoning; Yang, Beibei; Wang, Dehui

2015-01-01

To further evaluate the efficacy and safety of a pollen blocker cream against dust-mite allergy. A multicenter, randomized, double-blind, placebo-controlled, crossover trial was conducted in a Chinese population. Patients diagnosed with perennial allergic rhinitis, sensitive to dust-mite allergy including Dermatophagoides farinae and Dermatophagoides pteronyssinus were randomly allocated to receive a pollen blocker cream or placebo, which was applied and spread evenly to the lower internal nose region three times daily for a total of 30 days. The primary outcome measurements for efficacy were total nasal symptom score (TNSS) and individual nasal symptom score (iNSS). Adverse events were also monitored. After application of a pollen blocker, the mean TNSS decreased from 23.1 to 13.8, the decrease of the pollen blocker group (9.3) was highly significant compared with the placebo group (5.2; p 0.05), and no severe systematic reactions were observed. Pollen Blocker is a safe and effective alternative to the drugs for treatment of AR, especially for Chinese people allergic to dust-mite allergy.

Diffusion coefficients of Fokker-Planck equation for rotating dust grains in a fusion plasma

Science.gov (United States)

Bakhtiyari-Ramezani, M.; Mahmoodi, J.; Alinejad, N.

2015-11-01

In the fusion devices, ions, H atoms, and H2 molecules collide with dust grains and exert stochastic torques which lead to small variations in angular momentum of the grain. By considering adsorption of the colliding particles, thermal desorption of H atoms and normal H2 molecules, and desorption of the recombined H2 molecules from the surface of an oblate spheroidal grain, we obtain diffusion coefficients of the Fokker-Planck equation for the distribution function of fluctuating angular momentum. Torque coefficients corresponding to the recombination mechanism show that the nonspherical dust grains may rotate with a suprathermal angular velocity.

Sensitivity of transatlantic dust transport to chemical aging and related atmospheric processes

KAUST Repository

Abdelkader, Mohamed; Metzger, Swen; Steil, Benedikt; Klingmü ller, Klaus; Tost, Holger; Pozzer, Andrea; Stenchikov, Georgiy L.; Barrie, Leonard; Lelieveld, Jos

2017-01-01

We present a sensitivity study on transatlantic dust transport, a process which has many implications for the atmosphere, the ocean and the climate. We investigate the impact of key processes that control the dust outflow, i.e., the emission flux

Dust as a surfactant

International Nuclear Information System (INIS)

Ignatov, A M; Schram, P P J M; Trigger, S A

2003-01-01

We argue that dust immersed in a plasma sheath acts as a surfactant. By considering the momentum balance in a plasma sheath, we evaluate the dependence of the plasma surface pressure on the dust density. It is shown that the dust may reduce the surface pressure, giving rise to a sufficiently strong tangential force. The latter is capable of confining the dust layer inside the sheath in the direction perpendicular to the ion flow

Measuring device for control rod driving time

International Nuclear Information System (INIS)

Tanaka, Kazuhiko; Hanabusa, Masatoshi.

1993-01-01

The present invention concerns a measuring device for control driving time having a function capable of measuring a selected control rod driving time and measuring an entire control rod driving time simultaneously. A calculation means and a store means for the selected rod control rod driving time, and a calculation means and a store means for the entire control rod driving time are disposed individually. Each of them measures the driving time and stores the data independent of each other based on a selected control rod insert ion signal and an entire control rod insertion signal. Even if insertion of selected and entire control rods overlaps, each of the control rod driving times can be measured reliably to provide an advantageous effect capable of more accurately conducting safety evaluation for the nuclear reactor based on the result of the measurement. (N.H.)

Modular manual control device for manipulators

International Nuclear Information System (INIS)

Dzholdasbekov, U.A.; Lukyanov, A.T.; Slutsky, L.I.; Safontsev, E.A.; Dzhamalov, N.K.

1991-01-01

The device described in this patent comprises a base, a series of connected modules, each with a position pickup and a handle. One module is provided for each degree of mobility of the manipulator being controlled; the modular construction enables the control of manipulators with differing degrees of mobility. One rotary movement module and three orthogonal linear movement modules are provided. Each linear module has two parallel guides between which a carriage is supported for movement by balls. The position pickup is provided on the carriage. The rotary module comprises inner and outer casings, relative movement of which is detected by pickup. Further rotary pickups may be provided for rotation about axes. A close/open switch and a speed control pickup may also be provided. (author)

INFRARED LUMINOSITIES AND DUST PROPERTIES OF z ∼ 2 DUST-OBSCURED GALAXIES

International Nuclear Information System (INIS)

Bussmann, R. S.; Dey, Arjun; Jannuzi, B. T.; Borys, C.; Desai, V.; Sheth, K.; Soifer, B. T.; Le Floc'h, E.; Melbourne, J.

2009-01-01

We present SHARC-II 350 μm imaging of twelve 24 μm bright (F 24μm > 0.8 mJy) Dust-Obscured Galaxies (DOGs) and Combined Array for Research in Millimeter-wave Astronomy (CARMA) 1 mm imaging of a subset of two DOGs. These objects are selected from the Booetes field of the NOAO Deep Wide-Field Survey. Detections of four DOGs at 350 μm imply infrared (IR) luminosities which are consistent to within a factor of 2 of expectations based on a warm-dust spectral energy distribution (SED) scaled to the observed 24 μm flux density. The 350 μm upper limits for the 8 non-detected DOGs are consistent with both Mrk 231 and M82 (warm-dust SEDs), but exclude cold dust (Arp 220) SEDs. The two DOGs targeted at 1 mm were not detected in our CARMA observations, placing strong constraints on the dust temperature: T dust > 35-60 K. Assuming these dust properties apply to the entire sample, we find dust masses of ∼3 x 10 8 M sun . In comparison to other dusty z ∼ 2 galaxy populations such as submillimeter galaxies (SMGs) and other Spitzer-selected high-redshift sources, this sample of DOGs has higher IR luminosities (2 x 10 13 L sun versus 6 x 10 12 L sun for the other galaxy populations) that are driven by warmer dust temperatures (>35-60 K versus ∼30 K) and lower inferred dust masses (3 x 10 8 M sun versus 3 x 10 9 M sun ). Wide-field Herschel and Submillimeter Common-User Bolometer Array-2 surveys should be able to detect hundreds of these power-law-dominated DOGs. We use the existing Hubble Space Telescope and Spitzer/InfraRed Array Camera data to estimate stellar masses of these sources and find that the stellar to gas mass ratio may be higher in our 24 μm bright sample of DOGs than in SMGs and other Spitzer-selected sources. Although much larger sample sizes are needed to provide a definitive conclusion, the data are consistent with an evolutionary trend in which the formation of massive galaxies at z ∼ 2 involves a submillimeter bright, cold-dust, and star

Lunar Dust Mitigation Screens

Science.gov (United States)

Knutson, Shawn; Holloway, Nancy

With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

Reducing dust and allergen exposure in bakeries

Directory of Open Access Journals (Sweden)

Howard J Mason

2017-12-01

Full Text Available Bakers have a continuing high incidence of occupational allergic asthma. In factory bakeries they are exposed not only to flour dust containing allergens, but also improvers whose ingredients enhance the strength and workability of the dough and its speed of rising. Improvers are flour-based but can contain added soya, fungal or bacterial enzymes that are also allergenic, as well as vegetable oil, calcium sulphate/silicate and organic esters. This study investigated the dustiness of the components used in factory bakeries and whether altering improver ingredients could reduce dust and allergen exposure. A standardised rotating drum test was employed on the individual components, as well as a representative improver and three practicable improver modifications by decreasing calcium sulphate, calcium silicate or increasing oil content. Levels of dust, the allergens wheat flour amylase inhibitor (WAAI and soya trypsin inhibitor (STI were measured in the generated inhalable, thoracic and respirable sized fractions. A “scooping and pouring” workplace simulation was also performed. Initial tests showed that dustiness of several wheat flours was relatively low, and even lower for soya flour, but increased in combination with some other improver components. All three improver modifications generally reduced levels of dust, STI and WAAI, but increasing oil content significantly decreased dust and STI in comparison to the standard improver and those improvers with reduced calcium silicate or sulphate. The simulation demonstrated that increased oil content reduced inhalable levels of gravimetric dust, STI and WAAI. Changing improver formulation, such as increasing oil content of flour by a small amount, may represent a simple, practical method of reducing bakery workers’ exposure to dust and allergens where improvers are used. It may be a useful adjunct to engineering control, changes to work practices and appropriate training in reducing the risk to

Real-time measurement of dust in the workplace using video exposure monitoring: Farming to pharmaceuticals

International Nuclear Information System (INIS)

Walsh, P T; Forth, A R; Clark, R D R; Dowker, K P; Thorpe, A

2009-01-01

Real-time, photometric, portable dust monitors have been employed for video exposure monitoring (VEM) to measure and highlight dust levels generated by work activities, illustrate dust control techniques, and demonstrate good practice. Two workplaces, presenting different challenges for measurement, were used to illustrate the capabilities of VEM: (a) poultry farming activities and (b) powder transfer operations in a pharmaceutical company. For the poultry farm work, the real-time monitors were calibrated with respect to the respirable and inhalable dust concentrations using cyclone and IOM reference samplers respectively. Different rankings of exposure for typical activities were found on the small farm studied here compared to previous exposure measurements at larger poultry farms: these were mainly attributed to the different scales of operation. Large variations in the ratios of respirable, inhalable and real-time monitor TWA concentrations of poultry farm dust for various activities were found. This has implications for the calibration of light-scattering dust monitors with respect to inhalable dust concentration. In the pharmaceutical application, the effectiveness of a curtain barrier for dust control when dispensing powder in a downflow booth was rapidly demonstrated.

Extracting lunar dust parameters from image charge signals produced by the Lunar Dust Experiment

Science.gov (United States)

Stanley, J.; Kempf, S.; Horanyi, M.; Szalay, J.

2015-12-01

The Lunar Dust Experiment (LDEX) onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) is an impact ionization dust detector used to characterize the lunar dust exosphere generated by the impacts of large interplanetary particles and meteor streams (Horanyi et al., 2015). In addition to the mass and speed of these lofted particles, LDEX is sensitive to their charge. The resulting signatures of impact events therefore provide valuable information about not only the ambient plasma environment, but also the speed vectors of these dust grains. Here, impact events produced from LDEX's calibration at the Dust Accelerator Laboratory are analyzed using an image charge model derived from the electrostatic simulation program, Coulomb. We show that parameters such as dust grain speed, size, charge, and position of entry into LDEX can be recovered and applied to data collected during LADEE's seven-month mission.

Control Board Digital Interface Input Devices – Touchscreen, Trackpad, or Mouse?

Energy Technology Data Exchange (ETDEWEB)

Thomas A. Ulrich; Ronald L. Boring; Roger Lew

2015-08-01

The authors collaborated with a power utility to evaluate input devices for use in the human system interface (HSI) for a new digital Turbine Control System (TCS) at a nuclear power plant (NPP) undergoing a TCS upgrade. A standalone dynamic software simulation of the new digital TCS and a mobile kiosk were developed to conduct an input device study to evaluate operator preference and input device effectiveness. The TCS software presented the anticipated HSI for the TCS and mimicked (i.e., simulated) the turbine systems’ responses to operator commands. Twenty-four licensed operators from the two nuclear power units participated in the study. Three input devices were tested: a trackpad, mouse, and touchscreen. The subjective feedback from the survey indicates the operators preferred the touchscreen interface. The operators subjectively rated the touchscreen as the fastest and most comfortable input device given the range of tasks they performed during the study, but also noted a lack of accuracy for selecting small targets. The empirical data suggest the mouse input device provides the most consistent performance for screen navigation and manipulating on screen controls. The trackpad input device was both empirically and subjectively found to be the least effective and least desired input device.

From Desert to Dessert: Why Australian Dust Matters.

Science.gov (United States)

Hunter, K. A.; Mackie, D. S.; Boyd, P. W.; McTainsh, G. H.

2006-12-01

The growth of some types of phytoplankton in several parts of the world ocean, including much of the Southern Ocean, is limited by the supply of iron. Large Australian dust storms uplift, transport and abrade soils, to produce aeolian dust that is a significant source iron to the Southern Ocean. Atmospheric processes that enhance the dissolution of iron from aeolian dusts are of interest and have been studied for material from major dust producing regions like the Sahara, Gobi and Australian deserts; the reported solubility of iron from aeolian dusts ranges from <0.01% to 80%. The characteristic red soils, sands and dusts from Australia are generally believed to consist of quartz grains with a coating of fine grains and crystals of iron oxides, primarily hematite and goethite. The precise mineralogy of soil and dust grain coatings is poorly understood and it also not well known how the coatings are altered during uplift and transport to the ocean. Current models to understand the processes operating during the transport and atmospheric processing of dust include some generalisations and simplifications that are not always warranted and our work has shown the overlooked complexity of the system. Models for aeolian-iron dissolution based on Northern Hemisphere data commonly include the pollutants SOx and NOx. The modern Southern Hemisphere is less polluted and thus resembles past environmental systems. The dissolution of iron from soils of the Saharan, Gobi and Australian deserts in the presence of protons only (i.e. without SOx and NOx) occurs in two phases. The first, faster phase, representing up to 20% of total iron is via a surface-controlled mechanism. The rate determining variable is the exposed surface area of the iron oxides and not the size of the underlying quartz grain. The second, slower, phase of dissolution occurs via the transport-controlled formation of a leached layer. During the simulated aeolian abrasion of Australian soils from dust producing

Effect of ecological restoration programs on dust concentrations in the North China Plain: a case study

Science.gov (United States)

Long, Xin; Tie, Xuexi; Li, Guohui; Cao, Junji; Feng, Tian; Zhao, Shuyu; Xing, Li; An, Zhisheng

2018-05-01

In recent decades, the Chinese government has made a great effort in initiating large-scale ecological restoration programs (ERPs) to reduce the dust concentrations in China, especially for dust storm episodes. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover product, the ERP-induced land cover changes are quantitatively evaluated in this study. Two obvious vegetation protective barriers arise throughout China from the southwest to the northeast, which are well known as the Green Great Wall (GGW). Both the grass GGW and forest GGW are located between the dust source region (DSR) and the densely populated North China Plain (NCP). To assess the effect of ERPs on dust concentrations, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust) is applied to investigate the evolution of dust plumes during a strong dust storm episode from 2 to 8 March 2016. The WRF-DUST model generally performs reasonably well in reproducing the temporal variations and spatial distributions of near-surface [PMC] (mass concentration of particulate matter with aerodynamic diameter between 2.5 and 10 µm) during the dust storm event. Sensitivity experiments have indicated that the ERP-induced GGWs help to reduce the dust concentration in the NCP, especially in BTH (Beijing, Tianjin, and Hebei). When the dust storm is transported from the upwind DSR to the downwind NCP, the [PMC] reduction ranges from -5 to -15 % in the NCP, with a maximum reduction of -12.4 % (-19.2 µg m-3) in BTH and -7.6 % (-10.1 µg m-3) in the NCP. We find the dust plumes move up to the upper atmosphere and are transported from the upwind DSR to the downwind NCP, accompanied by dust decrease. During the episode, the forest GGW is nonsignificant in dust concentration control because it is of benefit for dry deposition and not for emission. Conversely, the grass GGW is beneficial in controlling dust erosion and is the dominant reason for [PMC] decrease in the NCP

Effect of ecological restoration programs on dust concentrations in the North China Plain: a case study

Directory of Open Access Journals (Sweden)

X. Long

2018-05-01

Full Text Available In recent decades, the Chinese government has made a great effort in initiating large-scale ecological restoration programs (ERPs to reduce the dust concentrations in China, especially for dust storm episodes. Using the Moderate Resolution Imaging Spectroradiometer (MODIS land cover product, the ERP-induced land cover changes are quantitatively evaluated in this study. Two obvious vegetation protective barriers arise throughout China from the southwest to the northeast, which are well known as the Green Great Wall (GGW. Both the grass GGW and forest GGW are located between the dust source region (DSR and the densely populated North China Plain (NCP. To assess the effect of ERPs on dust concentrations, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust is applied to investigate the evolution of dust plumes during a strong dust storm episode from 2 to 8 March 2016. The WRF-DUST model generally performs reasonably well in reproducing the temporal variations and spatial distributions of near-surface [PMC] (mass concentration of particulate matter with aerodynamic diameter between 2.5 and 10 µm during the dust storm event. Sensitivity experiments have indicated that the ERP-induced GGWs help to reduce the dust concentration in the NCP, especially in BTH (Beijing, Tianjin, and Hebei. When the dust storm is transported from the upwind DSR to the downwind NCP, the [PMC] reduction ranges from −5 to −15 % in the NCP, with a maximum reduction of −12.4 % (−19.2 µg m−3 in BTH and −7.6 % (−10.1 µg m−3 in the NCP. We find the dust plumes move up to the upper atmosphere and are transported from the upwind DSR to the downwind NCP, accompanied by dust decrease. During the episode, the forest GGW is nonsignificant in dust concentration control because it is of benefit for dry deposition and not for emission. Conversely, the grass GGW is beneficial in controlling dust erosion and is the

Effective mitigation efforts to reduce road dust near industrial sites: assessment by mobile pollution surveys.

Science.gov (United States)

DeLuca, Patrick F; Corr, Denis; Wallace, Julie; Kanaroglou, Pavlos

2012-05-15

Assessment of spatial variation of fugitive dust sources, particularly road dust track-out from industrial sites and its subsequent re-suspension is difficult with fixed air quality monitoring stations given their sparse distribution and the highly localized nature of road dust. Mobile monitoring was employed to measure levels of road dust in the industrial area of the City of Hamilton, Ontario, Canada. Results of this monitoring were used in a Fugitive Dust Control workshop held for local stakeholders, where fugitive dust control solutions were presented. After the workshop, the City of Hamilton and cooperative industrial groups executed enhanced street cleaning and individual industries and facilities performed on-site control activities. Post-workshop mobile air monitoring was performed for comparison to the initial values to determine effectiveness of these approaches. A regression model testing the difference pre- and post-workshop yielded a statistically significant difference in PM(10) measurements demonstrating improvement. The average value of PM(10) prior to the workshop was 114 μg/m(3). Post-workshop the average value dropped to 73 μg/m(3). Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical Prediction of Dust. Chapter 10

Science.gov (United States)

Benedetti, Angela; Baldasano, J. M.; Basart, S.; Benincasa, F.; Boucher, O.; Brooks, M.; Chen, J. P.; Colarco, P. R.; Gong, S.; Huneeus, N.;

Sahara Dust Cloud

Science.gov (United States)

2005-01-01

[figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24 A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean. These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward. In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005. In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the AIRS retrieved total water

Reduction of airborne radioactive dust by means of a charged water spray.

Science.gov (United States)

Bigu, J; Grenier, M G

1989-07-01

An electrostatic precipitator based on charged water spray technology has been used in an underground uranium mine to control long-lived radioactive dust and short-lived aerosol concentration in a mine gallery where dust from a rock breaking/ore transportation operation was discharged. Two main sampling stations were established: one upstream of the dust precipitator and one downstream. In addition, dust samplers were placed at different locations between the dust discharge and the end of the mine gallery. Long-lived radioactive dust was measured using cascade impactors and nylon cyclone dust samplers, and measurement of the radioactivity on the samples was carried out by conventional methods. Radon and thoron progeny were estimated using standard techniques. Experiments were conducted under a variety of airflow conditions. A maximum radioactive dust reduction of about 40% (approximately 20% caused by gravitational settling) at a ventilation rate of 0.61 m3/sec was obtained as a result of the combined action of water scrubbing and electrostatic precipitation by the charged water spray electrostatic precipitator. This represents the optimum efficiency attained within the range of ventilation rates investigated. The dust reduction efficiency of the charged water spray decreased with increasing ventilation rate, i.e., decreasing air residence time, and hence, reduced dust cloud/charged water droplets mixing time.

RIO EPICS device support application case study on an ion source control system (ISHP)

Energy Technology Data Exchange (ETDEWEB)

Sanz, Diego [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Ruiz, Mariano, E-mail: mariano.ruiz@upm.es [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Eguiraun, Mikel [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Arredondo, Iñigo [ESS Bilbao Consortium, Zamudio (Spain); Badillo, Inari; Jugo, Josu [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Vega, Jesús; Castro, Rodrigo [Asociación EURATOM/CIEMAT, Madrid (Spain)

2015-10-15

Highlights: • A use case example of RIO/FlexRIO design methodology is described. • Ion source device is controlled and monitored by means EPICS IOCs. • NIRIO EPICS device support demonstrates that is able to manage RIO devices. • Easy and fast deployment is possible using RIO/FlexRIO design methodology using NIRIO-EDS. • RIO/FlexRIO technology and EPICS are a good combination for support large scale experiments in fusion environments. - Abstract: Experimental Physics and Industrial Control System (EPICS) is a software tool that during last years has become relevant as a main framework to deploy distributed control systems in large scientific environments. At the moment, ESS Bilbao uses this middleware to perform the control of their Ion Source Hydrogen Positive (ISHP) project. The implementation of the control system was based on: PXI Real Time controllers using the LabVIEW-RT and LabVIEW-EPICS tools; and RIO devices based on Field-Programmable Gate Array (FPGA) technology. Intended to provide a full compliant EPICS IOCs for RIO devices and to avoid additional efforts on the system maintainability, a migration of the current system to a derivative Red Hat Linux (CentOS) environment has been conducted. This paper presents a real application case study for using the NIRIO EPICS device support (NIRIO-EDS) to give support to the ISHP. Although RIO FPGA configurations are particular solutions for ISHP performance, the NIRIO-EDS has permitted the control and monitoring of devices by applying a well-defined design methodology into the previous FPGA configuration for RIO/FlexRIO devices. This methodology has permitted a fast and easy deployment for the new robust, scalable and maintainable software to support RIO devices into the ISHP control architecture.

CV-Dust: Atmospheric aerosol in the Cape Verde region: carbon and soluble fractions of PM10

Science.gov (United States)

Pio, C.; Nunes, T.; Cardoso, J.; Caseiro, A.; Custódio, D.; Cerqueira, M.; Patoilo, D.; Almeida, S. M.; Freitas, M. C.

2012-04-01

Every year, billions of tons of eroded mineral soils from the Saharan Desert and the Sahel region, the largest dust source in the world, cross Mediterranean towards Europe, western Asia and the tropical North Atlantic Ocean as far as the Caribbean and South America. Many aspects of the direct and indirect effects of dust on climate are not well understood and the bulk and surface chemistry of the mineral dust particles determines interactions with gaseous and other particle species. The quantification of the magnitude of warming or cooling remains open because of the strong variability of the atmospheric dust burden and the lack of representative data for the spatial and temporal distribution of the dust composition. CV-Dust is a project that aims at provide a detailed data on the size distribution and the size-resolved chemical and mineralogical composition of dust emitted from North Africa using a natural laboratory like Cape Verde. This archipelago is located in an area of massive dust transport from land to ocean, and is thus ideal to set up sampling devices that are able to characterize and quantify dust transported from Africa. Moreover, Cape Verde's future economic prospects depend heavily on the encouragement of tourism, therefore it is essential to elucidate the role of Saharan dust may play in the degradation of Cape Verde air quality. The main objectives of CV-Dust project are: 1) to characterize the chemical and mineralogical composition of dust transported from Africa by setting up an orchestra of aerosol sampling devices in the strategic archipelago of Cape Verde; 2) to identify the sources of particles in Cape Verde by using receptor models; 3) to elucidate the role Saharan dust may play in the degradation of Cape Verde air quality; 4) to model processes governing dust production, transport, interaction with the radiation field and removal from the atmosphere. Here we present part of the data obtained throughout the last year, involving a set of more