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EN
Particle size distribution is an important factor governing whether aerosols can be deposited in various respiratory tract regions in humans. Recently, electronic cigarette (EC), as the alternative of tobacco cigarette, has become increasingly popular all over the world. However, emissions from ECs may contribute to both indoor and outdoor air pollution; moreover, comments about their safety remain controversial, and the number of users is increasing rapidly. In this investigation, aerosols were generated from ECs and studied in the indoor air and in a chamber under controlled conditions of radon concentration. The generated aerosols were characterized in terms of particle number concentrations, size, and activity distributions by using aerosol diffusion spectrometer (ADS), diffusion battery, and cascade impactor. The range of ADS assessment was from 10–3 µm to 10 µm. The number concentration of the injected aerosol particles was between 40 000 and 100 000 particles/cm3. The distribution of these particles was the most within the ultrafi ne particle size range (0–0.2 µm), and the other particle were in the size range from 0.3 µm to 1 µm. The surface area distribution and the mass size distribution are presented and compared with bimodal distribution. In the radon chamber, all distributions were clearly bimodal, as the free radon decay product was approximately 1 nm in diameter, with a fraction of 0.7 for a clean chamber (without any additional source of aerosols). The attached fraction with the aerosol particles from the ECs had a size not exceeding 1.0 µm.
EN
The survey of ambient airborne particle size distribution is important when the deposition of radioactive particles is considered in the human lung and the assessment of radiation hazard in occupational exposures or contaminated environments. CLOR (the Central Laboratory for Radiological Protection) in cooperation with CMI (the Central Mining Institute) performed simultaneous measurements of the activity size distribution of radon progeny and ambient aerosols using different types of aerosols. Measurements were performed in a radon chamber with a volume of 17m3, where radon was generated by a radium-226 open source, and ambient aerosols by an oil candle, vax candle, and incense sticks. Such measurements were also made in an aerosol depleted atmosphere after cleaning the chamber air by means of a high-efficiency pump and filters. The size distribution of radioactive aerosols containing radon progeny was measured by RPPSS (Radon Progeny Particle Size Spectrometer) with the measuring size ranging from 0.6 nm to approximately 2500 nm. The key parts of this device are the impaction plates and diffusion screen batteries, which collect aerosols of different sizes, and semiconductor alpha detectors which detect the activity of the collected particles. The SMPS (Scanning Mobility Particle Sizer Spectrometer) and APS (Aerodynamic Particle Sizer) were applied to evaluate the size distribution of all aerosols with sizes from approximately 3 nm to 20 μm. Based on the results obtained by these spectrometers, the activity size distributions and related dose conversion factors (DCF) were evaluated both for the exposed workers and the general population.
EN
Nowadays, there is increasing demand for the use of renewable energy sources such as woodchips. One of the important qualitative parameters of woodchips is the size distribution. The aim of this article is to determine the effect of a woodchipper disc’s torsional vibration on the evenness of woodchip length, as well as propose a mathematical solution to this problem by assuming one harmonic component of disc speed and the uniform feed of chipped material. The presented mathematical solution can be used to determine the unevenness of woodchip length when the parameters of torsional vibration are known.
EN
The aim of this work was to investigate the influence of distilled water flowrate in two different porousmembrane modules on the size of generated nitrogen nanobubbles. Modules had different diameter and number of membrane tubes inside the module. As bubbles are cut off from the membrane surface by a shear stress induced by the liquid flow, the change in the linear liquid velocity should result in a change of the generated bubble diameter. For both modules, higher flowrate of liquid induced generation of smaller bubbles, which was consistent with our expectations. This effect can help us in generation of bubbles of desired size.
EN
Finding an efficient way to eliminate fine dust (particle diameter of 1-15 µm) from a room can be a challenging problem. Acoustic radiation emitters are widely used to accelerate particle coagulation and sedimentation. In this study, we propose one more method for depositing harmful particles – dispersion of electrostatically charged particles. These particles attract uncharged particles from the air and accelerate coagulation. The paper is devoted to a comparison of methods for the acoustic and electrostatic sedimentation of aerosols. The mathematical model for the coagulation of aerosols on the basis of Smoluchowski’s equation is proposed in the options corresponding to acoustic and electrostatic coagulation. A number of conclusions about the most effective conditions of sedimentation were made on the basis of the analysis of a kernel type of Smoluchowski’s integral equation. The results of the experiments on acoustic and electrostatic sedimentation of the model aerosol media (coal dust) are given. The results of the calculations according to the mathematical model of coagulation taking into account the proposed mechanisms for the sedimentation of aerosols in the acoustic field and electrostatic charging of particles are given.
EN
The aim of the research was to identify aerosols of bacterial origin, including aerobic and anaerobic bacteria, peptidoglycans and endotoxins in working rooms of waste management facility, which included sorting and composting of municipal waste. Four sampling points were located in the plant: in the pre-sorting cab, in sorting hall at conveyor belts, in the composting bunkers hall, as well as in the front of entrance gate, as a sample of external background. Air samples for the presence of bacteria were collected using a 6-stage Andersen impactor, wherein two types of microbial media were loaded: TSA agar with defibrinated sheep blood for aerobic bacteria and Schaedler's agar for anaerobic bacteria. Air samples for the presence of endotoxins and peptidoglycans were carried out using 8-stage cascade impactor, wherein the glass fiber filters were provided. Biochemical API tests were used for a detailed identification of bacteria. Determination of peptidoglycans was carried out using the SLP test (Silkworm Larvae Plasma) and endotoxin - LAL assay (Limulus Amebocyte Lysate). The results of the quantitative analysis of bioaerosols at the three tested working rooms showed the following geometric mean (GM) concentrations: aerobic bacteria – 4348 cfu/m3 (geometric standard deviation, GSD = 1.14); anaerobic bacteria – 19914 cfu/m3 (GSD = 3.65); endotoxins – 173.6 ng/m33. Anaerobic bacteria were the dominant group and accounted for 82% of all identified microorganisms. A total of 22 species of bacteria, belonging to 13 genera was identified in waste management facility. The greatest taxonomic diversity was observed in the sorting area (21 species), composting – 15, while in the background samples – 13 species. Among the identified species, six (Actinomyces israelii, A. meyeri, A. naeslundii, Clostridium perfrin-gens, Proteus vulgaris, and Streptomyces spp. can be treated as potentially harmful to waste workers, as they were classified into the second risk group by the ordinance of Minister of Health from 2005. Analysis of size distributions of bacteria showed that they occurred mostly in the form of single cells with an aerodynamic diameter in the range of 1.1-2.1 µm, and in the range of 4.7-7.0 µm, where the process of aggregation of bacterial cells with organic dust particles takes place. In the case of endotoxins and peptidoglycans we found a gradual increase in the concentrations of particles with aerodynamic diameters in the range of 3.3-11.0 µm. On the basis of the study it can be stated that the working rooms in waste management facility were heavily contaminated with aerosols of bacterial origin. Examination provided the pioneer results for anaerobic bacteria, which were the dominant group. Bacteria that can pose a health risk to exposed workers were also found in the air. The analysis of particle size distribution suggests that the bioaerosols observed in these rooms can accumulate in the middle and upper respiratory tract of employees, causing irritation of the nose and throat.
7
Content available Mineral matter in municipal solid waste
EN
Municipal solid waste (MSW) contains mineral materials which are seldom considered as a potential resource. Currently, the waste management sector pays attention to recyclable parts, biodegradable material, waste-to-energy fraction, and residues after waste reuse and recycle. In contrast, this study focus as on the mineral matter in MSW. The aim was to analyze and discuss the sources of mineral matter in MSW, the impact which the minerals have on waste management technologies, and finally, the possibility to recycle the mineral matter. The contribution of inorganic matter in the MSW stream is significant (about 20 wt.%). In the years 2012–2015, the average content of mineral matter in mixed MSW in Poland ranged from 16 wt.% to 36 wt.%, and the content of organic in MSW ranged from 20 wt.% to 42 wt.%. Minerals in MSW have rather negative impact on waste management technologies and their final products, and can be sorted out from the MSW stream, either in the households or in a central sorting line. However, in central collection and separation systems it is difficult to obtain a mineral matter fraction in subsequent processing steps due to technological limitations (inefficiency of devices), high degree of waste fragmentation and pollution of mineral matter with other waste. This indicates a hampered ability to separate minerals in a form available for reuse, so an effective system should be based on improved segregation at the source.
PL
Celem pracy było porównanie właściwości fizykochemicznych odmian i nowych linii odmianowych komosy ryżowej. Materiałem badawczym były nasiona trzech odmian komosy ryżowej: Faro, Titicaca, Pinio oraz trzech linii odmianowych S1, S2 i S3. Przeprowadzono oznaczenia charakteryzujące wybrane właściwości fizykochemiczne. Stwierdzono, że badane odmiany i linie odmianowe cechują się zróżnicowanymi właściwościami fizykochemicznymi. Mogą stanowić źródło wartościowego białka i polifenoli. Odmiana Faro oraz linia S1 mogą być wykorzystane w przemyśle farmaceutycznym z uwagi na wysoką zawartość saponin. Odmiana Tiricaca jest obiecującym surowcem dla przemysłu spożywczego.
EN
The aim of this study was to compare physicochemical properties of cultivars and new cultivar lines of quinoa. Seeds of three varieties of quinoa: Faro, Titicaca, Puno and three cultivar lines S1, S2 and S3 were taken as experimental material. Assays characterizing selected physicochemical properties were performed. Based on the obtained results ts it was found that the tested varieties and cultivar lines are characterized by diverse physicochemical properties. They can be used as a valuable source of protein and polyphenols. Faro variation and the line S1 may be applied in pharmaceutical industry due to their high content of saponins. Titicaca is promising raw material for food industry.
EN
Nanoparticles from a HD-Diesel engine and their composition were investigated in the present paper. Three variants of fuel additivities were applied to allow the balances of certain tracer-substances after the tests: 2% of additives-free lube oil; 2% of market lube oil with additive package and Fe-based regeneration additive (FBC) with 40 ppm Fe. The analysed SMPS particle size distributions indicated that by blending of the market lube oil to the fuel the combined effects of metals or metal oxides from the additive packages and of the heavy HC’s from the lube oil matrix contribute the most to the increase of nuclei mode. From the masses of Fe, Zn and Ca, which were introduced with the fuel, only parts were found as integral masses at all ELPI-stages – Fe 43.5%, Zn 36.6%, Ca 65.5%. The majority of mass of some metals, or metal oxides emissions on ELPI-stages (up to 80%) is in the size ranges below 100 nm.
EN
The main advantages of using direct injection in an SI engine, such as lower fuel consumption and higher thermal efficiency, implicate a new problem concerning gasoline engines: the emission of particulate matter. The observed issue has been a significant direction of development of the contemporary DISI engine over the last decade. This paper contains an overview of the results of PN emission, which were obtained from experiments conducted at BOSMAL and from the literature. Current and future legal regulations regarding PN emissions were collated to the test results.
PL
Główne korzyści z zastosowania bezpośredniego wtrysku benzyny w silnikach ZI, takie jak mniejsze zużycie paliwa czy większa sprawność termiczna silnika, wiążą się także z problemem niespotykanym dotąd w silnikach ZI, tj. z emisją cząstek stałych. Przez ostatnią dekadę zjawisko to wyznaczyło kierunek rozwoju współczesnych silników benzynowych z bezpośrednim wtryskiem. Artykuł ten zawiera przegląd wyników badań emisji liczby cząstek stałych w trakcie różnych projektów badawczych zrealizowanych w Instytucie BOSMAL, a także przedstawionych w literaturze. Wyniki odniesiono do obecnych i przyszłych wymogów prawnych dotyczących emisji cząstek stałych.
11
EN
Acoustic radiation sources are successfully applied to cleaning rooms from dust of fairly large particle sizes (ten micrometers and larger). The sedimentation of fine aerosols (particle diameter of 1–10 microns) is a more complicated challenge. The paper is devoted to the substantiation of the acoustic sedimentation method for such aerosols. On the basis of the mathematical model analysis for aerosol sedimentation by the acoustic field the mechanisms of this process have been determined and include the particle coagulation acceleration and radiation pressure effect. The experimental results of the acoustic sedimentation of a model aerosol (NaCl) are shown. The calculation results according to the mathematical model for coagulation and sedimentation, on the basis of the Smolukhovsky’s equation taking into account various mechanisms of aerosol sedimentation by sound depending on the particle sizes and sound intensity, are given. The necessity to use intensive sources of high-frequency sound has been confirmed, suggesting that these sources must be located above dust clouds.
EN
Estimation of size distribution by image analysis is a key issue in mineral engineering. However, only the surface information of ore piles can be captured, which is a headache problem in this field while only a few researchers pay attention to this problem. A new surface probability model was proposed for estimation of size distribution on a conveyor belt based on the Chavez Model in this investigation. This model was tested and verified to have smaller errors in single size fraction but have bigger errors in multiple size fractions. Several error trends were found and a correction factor was introduced to correct the higher errors. A series of linear equations were developed to calculate this specific correction factor according to Dm (average particle size) and the height of pile. Therefore, empirical probability can be estimated by the specific correction factor and calculated probability, and the surface information of ore piles can be converted into the global information of piles.
EN
The objective of the paper was to analyse by means a laser diffraction method, the granulometric composition of dust which settled on various surfaces of factory floors, where pellet was produced. A laser analyser of the size of particles MASTERSIZER 2000 was used in the research. Based on the research, it was found out that the sample of dust contained a limited amount of fractions particularly dangerous for health, i.e. PM4 and PM10 respectively 1.4% and 5.1%. The content of particles of dimension up to 100 μm did not exceed 60% of total volume of the analysed dust. Moreover, a shape of particles was analysed with the use of optic and scanning microscope and NIS –Elements BR software. Values of shape coefficients and histograms of their distribution were determined. Furthermore, relations between the size of particles and its shape were described.
PL
Celem pracy była analiza metodą dyfrakcji laserowej składu granulometrycznego pyłów osiadłych na różnych powierzchniach hal, w których produkowano pelet. W badaniach wykorzystano laserowy analizator wielkości cząstek model MASTERSIZER 2000. Na podstawie badań stwierdzono, że próbki pyłu zawierały ograniczone ilości frakcji szczególnie niebezpiecznych dla zdrowia, tj. PM4 oraz PM10 odpowiednio 1,4% oraz 5,1%. Zawartość cząstek o wymiarach do 100 μm nie przekraczała 60% ogólnej objętości analizowanego pyłu. Analizowano również kształt cząstek z wykorzystaniem mikroskopu optycznego i skaningowego oraz oprogramowania NIS-Elements BR. Wyznaczono wartości współczynników kształtu oraz określono histogramy ich rozkładu. Określono również zależności zachodzące pomiędzy rozmiarem cząstek a jej kształtem.
EN
The article presents investigation on the grinding rate constant. A selection function was measured for different raw materials using a ball mill, and effects of the grinding ball diameter and feed particle sizes on the materials grinding rate constant were investigated. The study was conducted for the mill on a semi-technical scale. The process was carried out periodically using several sets of grinding media. Relations for all investigated materials were expressed by the modified Snow equation. Additionally, the descriptions of the grinding rate was examined. The tendency in the variation of the grinding rate constant with the particle size was similar for all materials used, and was independent of the ball diameter. The author used two selection functions derived theoretically by Tanaka.
EN
Crushing is a process which is widely used in mineral processing plants, cement factories, aggregates plants and some other industrial plants. Specific fracture energy of the particles is not the only fundamental property that is important: the particle strength also plays a significant role in determining the overall comminution properties of the material. In the drop weight test, a known mass falls through a given height onto a single particle providing an event that allows characterization of the ore under impact breakage. It is known that there are many difficulties and problems in the drop weight and twin pendulum test methods such as being laborious, requiring long test time and requiring a special apparatus. In this study, breakage behavior of slag in different laboratory crushers was investigated. A new size distribution model equation was developed by a t-family value evaluation approach, and the validity of equation was tested.
PL
Przedstawiono ocenę wpływu warunków nawilżania złoża w procesie granulacji talerzowej, na powstawanie i wzrost aglomeratów w okresie dostarczania cieczy wiążącej. Proces granulacji prowadzono w sposób okresowy w granulatorze talerzowym o średnicy D = 0,5 m i wysokości obrzeża H = 0,10 m, przy stałej prędkości obrotowej n = 0,167 s-1 i stałym kącie nachylenia osi talerza do poziomu α = 48°. Stosowano stałe objętościowe wypełnienie granulatora surowcem drobnoziarnistym ϕ = 0,05. Określano wpływ wilgotności złoża, intensywności nawilżania i położenia zraszacza na skład granulometryczny złoża otrzymanego bezpośrednio po zakończeniu dozowania cieczy wiążącej.
EN
Evaluation of the influence of bed wetting conditions during periodic disc granulation on the nucleation and growth of agglomerates is presented. The process of granulation was carried out in a disc granulator of diameter D = 0.5 m, rim height H= 0.1 m, at constant rotational speed n = 0.167 s-1 and slope angle between the disc and horizontal level α = 48°. A fixed volumetric disc filling with powder material equal to ϕ = 0.05 was used. The influence of bed moisture content, wetting intensity and location of sprinkler on particle size distribution of feed obtained after completing the wetting was determined.
17
Content available remote Metoda racjonalnego projektowania samozagęszczającego się betonu
PL
W pracy podano propozycję racjonalnej metody projektowania betonu samozagęszczającego się. W oparciu o badania wytrzymałości i urabialności tego betonu, ustalono że następujące czynniki: upakowanie, wymiary kruszywa, stosunek kruszywa drobnego do całkowitej zawartości kruszywa, zawartość popiołu lotnego, cementu i wody mają najważniejsze znaczenie. Wynika stąd, że te czynniki, których wielkość zakładano w metodzie projektowania betonu podanej przez Nan Su, są ważne i racjonalna metoda projektowania mieszanki powinna opierać się na danych doświadczalnych. Zaproponowana metoda racjonalnego projektowania betonu samozagęszczającego się obejmuje wszystkie jego klasy. Równocześnie jest ona prosta i pokazuje wykorzystanie danych doświadczalnych.
EN
This paper proposes a rational mix design procedure for Self Compacting Concrete (SCC). From the strength and workability studies conducted on SCC in the present investigation, it was noted that the parameters viz., packing factor, effective size of aggregate, fine aggregate - total aggregate ratio, fly ash content, cement content and water content influence the mix proportion to a great extent. It was hence felt that these parameters, which were assumed in case of Nan Su method of mix design, are of reasonable importance and a rational mix design methodology modifying the existing Nan Su method needs to be proposed. This rational mix design procedure can be adopted for designing any grade of self compacting concrete. In the present work a simplified and direct mix design methodology for SCC is proposed based on experimental observations.
18
Content available remote Spawanie stali – narażenie na cząstki zawarte w dymach spawalniczych
PL
W artykule przedstawiono wyniki badania stężeń i rozkładów wymiarowych cząstek emitowanych do środowiska pracy podczas spawania stali elektrodami ER-150/F 6013. Badania wykonane metodą filtracyjno-wagową (próbniki typu PCIS) oraz metodami zliczania (AERO-TRAK, GRIMM, DUST-TRAK) wykazały, że podczas całego dnia pracy spawacz może być narażony na zmienne ilości cząstek z reguły o wymiarach poniżej 10 mikrometrów, przy czym dymy spawalnicze zwykle zawierają znaczne ilości cząstek ultradrobnych i drobnych o wymiarach poniżej 1 mikrometra.
EN
The article presents results of investigation of concentrations and size distribution of particles emitted to the working environmental during welding of steel with using of electrodes type ER-150/F 6013. Investigations carried out with gravimetric method (PCIS samplers) and with counting methods (AERO-TRAK, GRIMM, DUST-TRAK) shown, that during whole working day welder can be exposed on variable amount of particles usually with diameter less then 10 micrometer, however welding fumes contain considerable amount of ultrafine and fine particles with diameter less than 1 micrometer.
19
Content available remote Nucleation and granule formation during disc granulation process
EN
The study of nucleation and granule formation in a bed of fine-grained material during the phase of batch damping in the process of periodical disc granulation was conducted. The study was carried out on laboratory disc (diameter - 0.5 m), with the use of constant disc filling with powder material, constant slope angle 50 between the disk axis and level and constant rotational speed of device. Foundry bentonite was used as the examined material and distilled water as a binding liquid. The binding liquid was added in the form of droplets having constant size. The size of droplets was changed in the range 2.44.9 mm. The influence of number and size of binding liquid droplets delivered to bed, as well as of their delivery height on the size distribution of nuclei generated in the dumping phase was determined.
PL
W pracy przedstawiono wyniki badań wpływu wybranych parametrów procesowo-aparaturowych na właściwości produktu wytworzonego w procesie mokrej granulacji talerzowej w układzie ciągłym. Jako zmienne parametry stosowano prędkość obrotową talerza, kąt nachylenia jego osi oraz natężenie podawania surowca proszkowego. Jako modelowy materiał drobnoziarnisty stosowano bentonit odlewniczy, a jako ciecz wiążącą użyto wodę destylowaną. Stosowano stały stosunek natężenia podawania cieczy wiążącej do natężenia podawania surowca, równy 0,4 kg cieczy/kg proszku. Opracowano zależność wpływu badanych parametrów na wartość średniego rozmiaru granul w produkcie końcowym, otrzymanym po ustaleniu się warunków procesu ciągłego.
EN
The paper presents the results of the study of process-equipment parameters influence on the properties of product formed in the continuous, wet, drum granulation process. Plate rotational speed, the inclination angle of its axis and the intensity of powder material delivery were treated as variable parameters. Foundry bentonite powder was used as model of fine-grained material and distilled water as binding liquid. Constant ratio between the intensity of binding liquid delivery and the intensity of raw material delivery, equal to 0.4 kg of liquid/kg of powder, was applied. The influence of study parameters on the average size of granules in the final product obtained after the establishment of continuous process conditions was worked out in this study.
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