Wyniki wyszukiwania - Biblioteka Nauki

1

Investigation of Dust Levels in Different Areas of Underground Coal Mines

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Onder M. , Onder S. , Akdag T. , Ozgun F.

International Journal of Occupational Safety and Ergonomics

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2009

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tom Vol. 15, No. 1

125--130

EN

Dust concentration levels in underground coal mines are of primary importance and have to be controlled to prevent pulmonary disease in miners. Different mining areas are exposed to different dust levels and to minimize the probability of occupational respiratory disease of coal miners, it is necessary to evaluate dust concentration in the different working areas. This study aimed to evaluate dust concentration levels in different areas of underground coal mines. Data obtained from the measurements in 1978–2006 were evaluated with the analysis of variance (ANOVA) and the Tukey-Kramer procedure. It was concluded that production areas had higher dust concentration levels; thus, production workers may have respiratory disorders related to exposure to coal dust in their work environment.

2

Analysis of Minimum Ignition Temperatures in Chosen Wooden Dust Layers Exposed to External Heated

100%

Półka M.

Archivum Combustionis

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2009

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tom Vol. 29 nr 1-2

5-10

EN

The results of experimental laboratory studies of minimum ignition temperatures for chosen wood dust in heap up layer have been presented in this paper. Samples of wood dust of varying layer thickness and granulation were exposed to a heated furnace plate according to PN-EN 50281:2002. Basing on previous tests related to chosen dusts stated was the allowed minimum temperature of installation or electrical devices which are exposed to contact with dust created of layers.

3

Gray Extinction in the Orion Trapezium

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Krełowski J. , Galazutdinov G. A. , Strobel A. , Mulas G.

Acta Astronomica

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2016

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tom Vol. 66, No. 4

469--480

EN

We estimated distances to several Orion Trapezium stars using our CaII-method and confirm the distance recommended by Menten et al. However, we found that in the case of HD 37020 both individual distances (based on the trigonometric VLBI parallax and/or CaII-method) differ from the spectrophotometric distance by a factor of 2.5. We interpret this fact as a result of presence of gray (neutral) extinction of about 1.8 mag in front of this star. The correctness of the applied spectral type/ luminosity class, Sp/L, (based on new original spectra from HARPS-N) and measurements of color indices is discussed

4

Stars with ISM Polarization Observed with HPOL

80%

Weitenbeck A. J.

Acta Astronomica

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1999

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tom Vol. 49, No. 1

59--71

EN

Polarization data are given for stars whose polarizations are mostly interstellar which were observed for various programs with the University of Wisconsin spectropolarimeter (HPOL) during 1989-1994.

5

Stars with ISM Polarization Observed with HPOL. III

80%

Weitenbeck A. J.

Acta Astronomica

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2008

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tom Vol. 58, No. 4

433--439

EN

Polarization data are given for stars whose polarizations are mostly interstellar which were observed with the University of Wisconsin spectropolarimeter (HPOL) during 1995-2004.

6

Collection of mobile dust in the T2R reversed field pinch

80%

Bykov I. , Bergsaker H. , Ogata D. , Petersson P. , Ratynskaia S.

Nukleonika

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2012

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tom Vol. 57, No. 1

55-60

EN

Intensive plasma-wall interactions in fusion devices result in the impurity production and the formation of films of redeposited material, debris and dust. In present day devices, with short pulses, the mobile dust does not pose any serious operational problems, but it is a matter of serious concern for ITER and for later power producing devices with a high duty cycle. We report results of a dust collection experiment carried out at the T2R reversed field pinch device and related heavy impurity flux measurements. Dust and impurities were collected on passive Si surface probes and on ultralow density silica aerogel collectors. The advantage of the latter method is the possibility of nondestructive capture of the micron- and submicron-sized dust particles. The toroidal and radial deposition fluxes of dust particles and impurities are estimated and discussed in the light of the dominant forces acting on the dust.

7

Buckminster Fullerene and Interstellar Extinction

80%

Gnaciński P.

Acta Astronomica

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2023

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tom Vol. 73, No. 2

179--186

EN

Most of over 500 Diffuse Interstellar Bands (DIBs) can not be assigned to any carrier. Only the infrared DIBs at 9348-9632 Å are known to be absorption lines of the buckminster fullerene cation C60+. We show that equivalent width of the 9577 Å DIB is correlated with the bump area on the ultraviolet extinction curve and with interstellar reddening E(B-V). Physical conditions must be similar for forming dust particles responsible for the UV-bump and forming C60+.

8

On the Relation between Interstellar Spectral Features and Reddening

80%

Krełowski J. , Galazutdinov G. , Godunova V. , Bondar A.

Acta Astronomica

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2019

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tom Vol. 69, No. 2

159--175

EN

It is well known that interstellar spectral features correlate with color excess E(B-V). This suggests that measuring intensities of these features allows one to estimate reddening of stars. The aim of this paper is to check how tight intensities of interstellar diffuse bands (DIBs) are related to the amount of extinction, measured using E(B-V). We have measured equivalent widths of the strongest DIBs (centered at λλ 5780.6 Å, 5797.0 Å, 6196.0 Å, 6379.3 Å, 6613.5 Å, and 8620 Å), as well as of CH (near 4300.3 Å) and CH+ (near 4232.5 Å) in high resolution, high S/N ratio échelle spectra from several spectrographs. The equivalent widths of the 8620 DIB in noisy spectra were measured using a template which was constructed using the high quality spectrum of BD+40 4220. DIB relations with the color excess in the range 0.1-2.0 mag were examined. Our analysis demonstrates that all the above mentioned interstellar spectral features (except for, perhaps, 6379 DIB) do correlate with E(B-V) relatively tightly (with the Pearson's correlation coefficient of 0.8+). Moreover, the observed scatter is apparently not caused by measurement errors but of physical origin. We present several examples where the strength ratios of a DIB/molecule to E(B-V) are different than the average.

9

Analysis of dustiness state in a driven underground dog heading ventilating by auxiliary air-duct

80%

Brodny J. , Tutak M.

Management Systems in Production Engineering

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2020

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tom nr 2 (28)

73--77

EN

Dustiness of the mine atmosphere during carrying out exploitation is one of the most hazardous factors threaten to health and life of employees. Also it is large hazard for all type of mechanical and electrical devices operating in mining headings. Coal dust is also very dangerous due to its possibility of explosion. Currently applied technologies of rock mass mining process, entire transport process of output and applied ventilation system cause that rock and coal dust is presented practically in each of the mining heading. Practically, is impossible to eliminate dust from mining headings. However, one can determine its parameters and potential ways its displacement. In the paper there is presented modeling research methodology of dustiness state in a driven dog heading. Developed model is the basis for this methodology, including the diphase flow of mixture of air and dust in the mining heading. Analysis was performed for real driven dog heading. Based on performed analyses, distributions of particular fraction and movement trajectories of selected dust grains were determined. Developed methodology gives a lot of opportunities for analysis of dustiness state in mining headings and in other compartments. It enables to determine parameters of particular grains and their impact on ventilation parameters of the air stream in the tested headings. Obtained results can also be used to reduce dust hazard.

10

Stars with ISM Polarization Observed with HPOL. II

80%

Weitenbeck A. J.

Acta Astronomica

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2004

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tom Vol. 54, No. 1

87--102

EN

Polarization data are given for stars whose polarizations are mostly interstellar which were observed with the University of Wisconsin spectropolarimeter (HPOL) during 1995-2003. Several cases are found for which K in the Serkowski Law for ISM polarization is higher than allowed by published formulas.

11

Wykorzystanie metody optoelektronicznej w pomiarach stężenia pyłu zawieszonego PM2,5 i PM10

80%

Mazur M. , Dziugieł M.

Ochrona Powietrza i Problemy Odpadów

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2011

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tom Vol. 45, nr 3

94-103

PL

Pomiary ilości i stężenia cząstek stałych w powietrzu prowadzone są w celu określenia stanu zanieczyszczenia atmosfery na danym obszarze. W niniejszej pracy przedstawiono wyniki badań stężenia pyłu zawieszonego PM2,5 i PM10 w powietrzu, przeprowadzonych z wykorzystaniem optoelektronicznego analizatora wielkości cząstek typu IPS-P (Kamika Instruments) z izokinetycznym poborem strumienia powietrza. Pomiary odniesienia przeprowadzono referencyjnym pyłomierzem grawimetrycznym niskoobjętościowym PNS3D15/LVS3D (Atmoservice). Pomiary prowadzono równolegle w punkcie pomiarowym zlokalizowanym na terenie Akademii Górniczo- Hutniczej w Krakowie. Badania realizowane były w trybie 24h przez okres 3 miesięcy, od 15.01.2011 do 31.03.2011r., w różnych warunkach meteorologicznych. Uzyskane wyniki porównano oraz poddano analizie w kierunku wpływu wybranych czynników meteorologicznych na uzyskane wartości stężeń.

EN

The use of the optoelectronic method in the PM2.5 and PM10 mass concentration measurements Particulates number and mass concentration measurements in the air are conducted to determine the atmosphere condition in the area. This paper presents the results of PM2.5 and PM10 mass concentration measurements in the air, carried out with optical/electronic particle size analyzer type IPS-P (Kamika Instruments) with isokinetic air stream aspiration. Reference measurements were carried out with low-volume dust gravimetric sampler PNS3D15/LVS3D (Atmoservice). Measurements were carried out simultaneously at the measuring point located at the AGH University of Science and Technology in Krakow. Daily studies were made in different weather conditions for a 3 months period from 15.01.2011 to 31.03.2011. The results were compared and analyzed in terms of the impact of selected meteorological factors on the mass concentration results.

12

Organic matter sources in aerosol PM10 from Wrocław, Poland

80%

Rybicki M. , Górka M. , Simoneit B. R. T. , Marynowski L.

Geology, Geophysics and Environment

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2014

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tom Vol. 40, no. 1

122

EN

The natural and anthropogenic contributions of hydrocarbon groups (aliphatic and aromatic), as well as total organic carbon, in atmospheric PM10 dust (particulate matter < 10 (µm) collected from Wrocław (SW Poland) were assessed using combined molecular (gas chromatography-mass spectrometry GC-MS) and stable carbon isotopic (isotope-ratio mass spectrometry IR-MS) analyses. The PM10 samples were taken using the hi-flow sampler Stamplex Air Division with Whatmann quartz filter (0.06237 m2), and a constant air flow of 1.13 m3/ min in the seasonal sampling program in 2007, and represent air pollution in all months of the year. The δ13C values of the total carbon varied seasonally from -27.6 to -25.3‰. The isotopic mass balance calculations showed greater coal burning input, reaching 70.5%, in the heating season and dominant transported sources 47.0% in the vegetative season. The δ13C values of the aliphatic fractions (from -36.6‰ to -29.4‰), indicated a dominant anthropogenic origin (gasoline/diesel/ coal combustion). The n-alkane distribution with relatively low CPI (carbon preference index) values confirmed that coal combustion and petroleum product use in vehicles were important sources of the PM10 in Wroclaw. On the other hand, high values of % WNA (wax n-alkane content), especially in vegetative season, and Cmax (carbon number maximum) ≥27 in 81% of the samples suggested that the influence of biogenic sources was also significant. Petroleum and coal combustion emissions were confirmed by the presence of hopanes and moretanes. The molecular analysis of the concentrations and diagnostic ratios of the polycyclic aromatic hydrocarbons (PAHs) and the δ13C values of the aromatic fractions (from -35.4‰ to -26.8‰) indicated that the main PAH sources were also represented collectively by combustion of liquid fuels and coal. Based on PAH discrimination diagrams it is also clear that the main organic carbon source is derived from coal, biomass and petroleum combustion in both seasons. However, taking into account the PAH concentrations during the vegetative and heating seasons, coal and biomass burning seem to be their major source. The high concentration of polar organic compounds such as levoglucosan, mannosan and galactosan confirmed a significant contribution of biomass burning to the total anthropogenic input, especially in the heating season. The general conclusions derived from coupling of organic tracer analysis and carbon isotopic data of PM10 was that the total carbon (including insoluble soot) is likely derived from fossil fuel combustion, while the extractable organic matter is a mixture from different sources with significant inputs of biomass burning. We have also shown that dominant organic tracers do not always represent the major input source in aerosol PM and the unresolved part of the organic matter (soot) is important in the carbon budget.

13

Dust arising during steelmaking processes

80%

Popielska-Ostrowska P. , Siwka J. , Sorek S. , Niesler M.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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tom Vol. 55, nr 2

772--776

EN

Purpose: This paper describes the dust arising during steelmaking processes. Design/methodology/approach: Steelmaking dusts may be a viable alternative for obtaining valuable and widely used metal which is zinc. On the other hand, heavy metals, it was as dangerous to the environment, and this in turn means that development of steelmaking dusts in the best possible way. Findings: The analysis of the formation of steelmaking dust. Research limitations/implications: Understanding the mechanism of steelmaking dusts will help to increase the participation of zinc recycling from wastes. Practical implications: Contained zinc in the dust can be recovered from the positive economic effect, and neutralization of hazardous waste to the desired environmental effect. Origmalily/value: Description of the mechanism of steelmaking dust, with particular emphasis on the distribution of zinc. The information is very important in the development of metal recovery technology from waste.

14

Photometric Study of Kepler Asteroseismic Targets

80%

Molenda-Żakowicz J. , Jerzykiewicz M. , Frasca A.

Acta Astronomica

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2009

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tom Vol. 59, No. 2

213--237

EN

Reported are UBV and uvbyβ observations of 15 candidates for Kepler primary asteroseismic targets and 14 other stars in the Kepler field, carried out at the M.G. Fracastoro station of the Catania Astrophysical Observatory. These data serve to plot the 29 stars in two-parameter diagrams with the photometric indices (such as B-V or δm1) and the atmospheric parameters (such as the MK type or [Fe/H]) as coordinates. The two-parameter diagrams show no evidence of interstellar reddening. The photometric indices B-V and β are then used to derive photometric effective temperatures, Teff(B-V) and Teff(β). For Teff(B-V)>6400 K, the photometric effective temperatures turn out to be systematically higher than spectroscopic effective temperatures by 311±34 K and 346±91 K for Teff(B-V) and Teff(β), respectively. For Teff(B-V)<6250 K, the agreement between Teff(B-V) and the spectroscopic effective temperatures is very good. The photometric surface gravities, derived from c1 and β, show a range of about a factor of two greater than their spectroscopic counterparts do.

15

On the Distance Measurements in the Thin Milky Way Disk

80%

Krełowski J. , Strobel A. , Galazutdinov G. A. , Musaev F. , Bondar A.

Acta Astronomica

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2018

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tom Vol. 68, No. 3

285--300

EN

We present a test how far the direct, trigonometric parallax measurements and those, based on interstellar CaII H and K lines lead to distances to OB stars similar to those, based on spectrophotometrically determined ones. For this we use relatively nearby objects where the extinction effects are negligible. A test is based on observations of interstellar CaII H and K lines, that determine distances, in spectra of bright, nearby objects, free of extinction effects. For these objects one can find also trigonometric parallaxes. CaII H and K lines are weak in spectra of nearby stars and thus measurable only in high S/N ratio spectra. Such spectra being at our disposal also allow us to check the spectral classification of our targets and thus to comment the observed differences between distances acquired using different methods. Using four methods, we determined distances to nearly fifty B0-5 type stars, practically free of any extinction effects. We demonstrate that direct, astrometric, CaII H and K and spectrophotometric distances agree reasonably well in the absence of substantial interstellar extinction and when spectral classification is reliable. Apparently the absolute magnitude calibration, provided by Schmidt-Kaler, appears to be correct.

16

Organic dusts and farmers' lung problems

80%

Malmberg P.

Annals of Agricultural and Environmental Medicine

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1994

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tom 01

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nr 2

17

Mucosal membrane symptoms in relation to work operations in farmers

80%

Melbostad E. , Eduard W.

Annals of Agricultural and Environmental Medicine

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1994

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tom 01

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nr 2

18

Transient plasma loads to the ITER divertor surfaces : simulation experiments with QSPA Kh - 50

70%

Garkusha I. E. , Aksenov N. N. , Chuvilo A. A. , Landman I. S. , Makhlaj V. A. , Malykhin S. V. , Pugachev A. T. , Sadowski M. J. , Skladnik-Sadowska E.

Nukleonika

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2012

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tom Vol. 57, No. 2

167-170

EN

Experimental simulations of International Thermonuclear Experimental Reactor (ITER) transient events with relevant heat load and particle load parameters have been performed with a quasi-stationary plasma accelerator QSPA Kh-50. Pulsed plasma guns PPA and IBIS were also used for comparative studies of surface damages appearing under varying plasma parameters and sorts of plasma ions. Particular attention is paid to the material erosion due to particles ejection from the tungsten surfaces both in the form of droplets and solid dust. Generation mechanisms of the dust in the course of ELM-like plasma impacts to the tungsten surfaces are discussed

19

Pochodzenie materii meteorytowej

70%

Kozłowski S.

Acta Societatis Metheoriticae Polonorum

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2023

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tom 14

100-113

EN

In this article, I briefly review the history of the elements in the Universe, starting from cosmic inflation and ending at the creation of elements and minerals that we find in meteorites.

20

Use of Biological Adhesive for Effective Dust Suppression in Mining Operations

70%

Danilov A. S. , Smirnov Y. D. , Pashkevich M. A.

Journal of Ecological Engineering

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2015

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tom Vol. 16, nr 5

9--14

EN

This article explores modern methods of reclamation of lands disturbed processes of mining, based on monitoring disturbed lands using unmanned aircraft and dusty surfaces coated biologically active adhesive, biological foam. In the article new highly efficint methods of remote monitoring of environment components are considered on based of unmanned aircrafts. For monitoring, it is suggested to draw complexes based of small unmanned aircraft vehicle, equipped with special equipment (a digital camera, a thermal imaging camera, dust meter). Land reclamation on the biological stage is encouraged by using new bioadhesives, developed on the basis of polysaccharides and various microorganisms. This composition helps reduce the consumption of fertilizers, pesticides and other components, pioneer in growing crops on dusty surfaces in the disturbed lands. As a result of such an event, dust discharge from the surface technogenic structures is reduced up to 10 times.